This document analyzes the design of a beta type Stirling engine with a rhombic drive mechanism. It discusses various design considerations that must be accounted for, such as operating constraints, geometric constraints, and tolerances. The work focuses on the design methodology for a beta type Stirling engine and optimizing the phase angle by considering the effect of overlapping volume between the compression and expansion spaces. The aim is to develop a feasible design for a single cylinder, 1.5 kWe beta type Stirling engine for rural electrification applications.
Blu-Smart has carried out a comparative of India Vs countries like China, Belgium, Germany, Italy and many more with respect to electric vehicle policies, tax benefits & incentives applicable.
國際能源總署(IEA)每年定期公布「潔淨能源技術發展進程追蹤報告」(Tracking Clean Energy Progress, TCEP),過往主要是探討各技術是否符合IEA永續發展情境(Sustainable Development Scenario, SDS)所需趨勢;今年(2022年)則因應全球淨零排放,係針對55項對潔淨能源轉型至關重要的技術探討是否符合IEA 2050淨零路徑規劃軌跡(Net Zero Emission Scenario, NZE) ,並就如何“走上正軌”提供建議。該報告針對各項能源技術,分別提出全球淨零能源技術發展之最新趨勢、發展進程與挑戰、各國相關政策彙整、以及給政策制定者之建議。本報告分享工研院TIMES團隊整理之摘要分析,瞭解國際淨零評估下全球能源發展趨勢。
Video Surveillance Market in India - A Blueprint to Enhance SalesNeil Dave
The Video Surveillance Market in India is expected to reach USD 4.8 Billion by the year 2025, growing at a CAGR of 16.2% during the forecast period of 2020-2025.
The focus of this presentation is to keep Industry Participants abreast of major infrastructure developments across 8 key end-user sectors that are expected to result in high-value sales opportunities in the near term future.
This presentation also sheds light on the key trends within the Video Surveillance Market in India in terms of market size and growth forecasts, market segmentation, market drivers and restraints.
Blu-Smart has carried out a comparative of India Vs countries like China, Belgium, Germany, Italy and many more with respect to electric vehicle policies, tax benefits & incentives applicable.
國際能源總署(IEA)每年定期公布「潔淨能源技術發展進程追蹤報告」(Tracking Clean Energy Progress, TCEP),過往主要是探討各技術是否符合IEA永續發展情境(Sustainable Development Scenario, SDS)所需趨勢;今年(2022年)則因應全球淨零排放,係針對55項對潔淨能源轉型至關重要的技術探討是否符合IEA 2050淨零路徑規劃軌跡(Net Zero Emission Scenario, NZE) ,並就如何“走上正軌”提供建議。該報告針對各項能源技術,分別提出全球淨零能源技術發展之最新趨勢、發展進程與挑戰、各國相關政策彙整、以及給政策制定者之建議。本報告分享工研院TIMES團隊整理之摘要分析,瞭解國際淨零評估下全球能源發展趨勢。
Video Surveillance Market in India - A Blueprint to Enhance SalesNeil Dave
The Video Surveillance Market in India is expected to reach USD 4.8 Billion by the year 2025, growing at a CAGR of 16.2% during the forecast period of 2020-2025.
The focus of this presentation is to keep Industry Participants abreast of major infrastructure developments across 8 key end-user sectors that are expected to result in high-value sales opportunities in the near term future.
This presentation also sheds light on the key trends within the Video Surveillance Market in India in terms of market size and growth forecasts, market segmentation, market drivers and restraints.
Electric Vehicles: Industry Analysis and ForecastLevVirine
Due to technology innovations battery cost is expected gradually decline in next few years. Incorrys expects that electric cars will reach cost parity with gasoline cars in after 2024. It will lead to significant growth in electric car production. The report includes:
- Electric Car Stock Per Country
- Market Share of New Electric Vehicles
- Charging Infrastructure Forecast
- Electric Vehicle Battery Cost Forecast
- Electric Vehicle Price vs. Battery Capacity and Range
- Electric Vehicle Efficiency Forecast
- Annual Sales of Electric Vehicles Forecast
- Total Number of Electric Vehicles Forecast
For more information please visit Incorrys web site: https://www.incorrys.com
Faststream’s Predictive maintenance platform uses condition-monitoring equipment to evaluate an asset’s performance in real-time in the manufacturing Industries. Using our Predictive maintenance for industry 4.0 we were able to prevent asset failure of various Factories and Manufacturing Companies. By analyzing production data to identify patterns and predict issues before they happen.
Using our IoT based Predictive Maintenance Solutions the Factory managers and machine operators can carry out scheduled maintenance and regularly repaired machine parts to prevent downtime. Our IoT allows for different assets and systems to connect, work together, share, analyze, and make actionable decisions on the data.
Faststream's Predictive Maintenance on Factory Maintenance helps maintenance managers and manufacturers to predict the likelihood of future failures and determine asset failure factors that could impact elevator operations. By incorporating Faststream Technologies IoT gateway, sensor node, and Microsoft Azure/AWS/Thinkspace Cloud platform, our solution can entitle with data statistics, state monitoring, fault alarming, remote management, maintenance supervision, emergency response advertisement placement, and other features.
An overview of potential future lifecycle impacts of low carbon vehicles. Shifting to hybrid and electric vehicles will mean that an increasing share of lifecycle GHG emissions come from the production of the vehicle and electricity. Presentation given at the annual LowCVP conference by Nik Hill, knowledge leader for transport technology at Ricardo-AEA
Over the past few years, India’s cities have been witnessing an increasing trend in road traffics. It is mainly because of the increase in motorization on the roads of Indian cities. This results into the issues like deteriorating the air quality and noise pollution. To get out of this gridlock there have been calls to promote public transport. It is in this context that electric vehicles can play a positive role, as there are several benefits associated with the shift from conventional petrol or diesel vehicles to electric vehicles. In spite of many positive benefits related to electric vehicle technology, certain challenges are also there like currently Electric Vehicle is associated with significant capital costs, certain safety parameters like a concern of a fire hazard. The use of solar energy converted in to electrical energy can be more environmental friendly. Using solar energy as an electrical energy to charge the vehicle batteries will reduce the cost on fuel.
Have you pulled your car up to the gas/petrol pump lately and been shocked by the high
price of gasoline? As the pump clicked past Rs1400 or 1500, maybe you thought about
trading in that SUV for something that gets better mileage. Or maybe you are worried
that your car is contributing to the greenhouse effect. Or maybe you just want to have
the coolest car on the block. Currently, there is a solution for all this problems, it's the
hybrid electric vehicle.
The vehicle is lighter and roomier than a purely electric vehicle, because there is less
need to carry as many heavy batteries. The internal combustion engine in hybrid-electric
is much smaller and lighter and more efficient than the engine in a conventional vehicle.
In fact, most automobile manufacturers have announced plans to manufacture their own
hybrid versions. Hybrid electric vehicles are all around us. Most of the locomotives we
see pulling trains are diesel-electric hybrids. Cities like Seattle have diesel-electric
buses -- these can draw electric power from overhead wires or run on diesel when they
are away from the wires. Giant mining trucks are often diesel-electric hybrids.
Submarines are also hybrid vehicles -- some are nuclear-electric and some are dieselelectric. Any vehicle that combines two or more sources of power that can directly or
indirectly provide propulsion power is a hybrid.
The talk explains basic properties of reverberation chambers and presents some exemplary practical chambers with their parameters. The normative chamber validation as well as emission measurements and immunity tests are briefly explained. Finally, advantages and disadvantages are discussed.
HYBRID ELECTRIC VEHICLES
1. INTRODUCTION
A hybrid electric vehicle (HEV) has two types of energy storage units, electricity and fuel.
Electricity means that a battery (sometimes assisted by ultracaps) is used to store the energy, and that an electromotor (from now on called motor) will be used as traction motor.
Fuel means that a tank is required, and that an Internal Combustion Engine (ICE, from now on called engine) is used to generate mechanical power, or that a fuel cell will be used to convert fuel to electrical energy. In the latter case, traction will be performed by the electromotor only. In the first case, the vehicle will have both an engine and a motor.
Depending on the drive train structure (how motor and engine are connected), we can distinguish between parallel, series or combined HEVs.
Depending on the share of the electromotor to the traction power, we can distinguish between mild or micro hybrid (start-stop systems), power assist hybrid, full hybrid and plug-in hybrid.
Depending on the nature of the non-electric energy source, we can distinguish between combustion (ICE), fuel cell, hydraulic or pneumatic power, and human power. In the first case, the ICE is a spark ignition engines (gasoline) or compression ignition direct injection (diesel) engine. In the first two cases, the energy conversion unit may be powered by gasoline, methanol, compressed natural gas, hydrogen, or other alternative fuels.
Motors are the "work horses" of Hybrid Electric Vehicle drive systems. The electric traction motor drives the wheels of the vehicle. Unlike a traditional vehicle, where the engine must "ramp up" before full torque can be provided, an electric motor provides full torque at low speeds. The motor also has low noise and high efficiency. Other characteristics include excellent "off the line" acceleration, good drive control, good fault tolerance and flexibility in relation to voltage fluctuations.
The front-running motor technologies for HEV applications include PMSM (permanent magnet synchronous motor), BLDC (brushless DC motor), SRM (switched reluctance motor) and AC induction motor.
A main advantage of an electromotor is the possibility to function as generator. In all HEV systems, mechanical braking energy is regenerated.
The maximum operational braking torque is less than the maximum traction torque; there is always a mechanical braking system integrated in a car.
The battery pack in a HEV has a much higher voltage than the SIL automotive 12 Volts battery, in order to reduce the currents and the I2R losses.
Accessories such as power steering and air conditioning are powered by electric motors instead of being attached to the combustion engine. This allows efficiency gains as the accessories can run at a constant speed or can be switched off, regardless of how fast the combustion engine is running. Especially in long haul trucks, electrical power steering saves a lot of energy.
In this minute lecture, the main cost components of electricity are presented, demonstrating large variations in electricity cost across countries, and across market segments.
Embedded systems, especially in-vehicle embedded systems, are ubiquitously related to our everyday life. The development of embedded systems greatly facilitates the comfort of people’s life, changes our view of things, and has a significant impact on society
Electric Vehicles: Industry Analysis and ForecastLevVirine
Due to technology innovations battery cost is expected gradually decline in next few years. Incorrys expects that electric cars will reach cost parity with gasoline cars in after 2024. It will lead to significant growth in electric car production. The report includes:
- Electric Car Stock Per Country
- Market Share of New Electric Vehicles
- Charging Infrastructure Forecast
- Electric Vehicle Battery Cost Forecast
- Electric Vehicle Price vs. Battery Capacity and Range
- Electric Vehicle Efficiency Forecast
- Annual Sales of Electric Vehicles Forecast
- Total Number of Electric Vehicles Forecast
For more information please visit Incorrys web site: https://www.incorrys.com
Faststream’s Predictive maintenance platform uses condition-monitoring equipment to evaluate an asset’s performance in real-time in the manufacturing Industries. Using our Predictive maintenance for industry 4.0 we were able to prevent asset failure of various Factories and Manufacturing Companies. By analyzing production data to identify patterns and predict issues before they happen.
Using our IoT based Predictive Maintenance Solutions the Factory managers and machine operators can carry out scheduled maintenance and regularly repaired machine parts to prevent downtime. Our IoT allows for different assets and systems to connect, work together, share, analyze, and make actionable decisions on the data.
Faststream's Predictive Maintenance on Factory Maintenance helps maintenance managers and manufacturers to predict the likelihood of future failures and determine asset failure factors that could impact elevator operations. By incorporating Faststream Technologies IoT gateway, sensor node, and Microsoft Azure/AWS/Thinkspace Cloud platform, our solution can entitle with data statistics, state monitoring, fault alarming, remote management, maintenance supervision, emergency response advertisement placement, and other features.
An overview of potential future lifecycle impacts of low carbon vehicles. Shifting to hybrid and electric vehicles will mean that an increasing share of lifecycle GHG emissions come from the production of the vehicle and electricity. Presentation given at the annual LowCVP conference by Nik Hill, knowledge leader for transport technology at Ricardo-AEA
Over the past few years, India’s cities have been witnessing an increasing trend in road traffics. It is mainly because of the increase in motorization on the roads of Indian cities. This results into the issues like deteriorating the air quality and noise pollution. To get out of this gridlock there have been calls to promote public transport. It is in this context that electric vehicles can play a positive role, as there are several benefits associated with the shift from conventional petrol or diesel vehicles to electric vehicles. In spite of many positive benefits related to electric vehicle technology, certain challenges are also there like currently Electric Vehicle is associated with significant capital costs, certain safety parameters like a concern of a fire hazard. The use of solar energy converted in to electrical energy can be more environmental friendly. Using solar energy as an electrical energy to charge the vehicle batteries will reduce the cost on fuel.
Have you pulled your car up to the gas/petrol pump lately and been shocked by the high
price of gasoline? As the pump clicked past Rs1400 or 1500, maybe you thought about
trading in that SUV for something that gets better mileage. Or maybe you are worried
that your car is contributing to the greenhouse effect. Or maybe you just want to have
the coolest car on the block. Currently, there is a solution for all this problems, it's the
hybrid electric vehicle.
The vehicle is lighter and roomier than a purely electric vehicle, because there is less
need to carry as many heavy batteries. The internal combustion engine in hybrid-electric
is much smaller and lighter and more efficient than the engine in a conventional vehicle.
In fact, most automobile manufacturers have announced plans to manufacture their own
hybrid versions. Hybrid electric vehicles are all around us. Most of the locomotives we
see pulling trains are diesel-electric hybrids. Cities like Seattle have diesel-electric
buses -- these can draw electric power from overhead wires or run on diesel when they
are away from the wires. Giant mining trucks are often diesel-electric hybrids.
Submarines are also hybrid vehicles -- some are nuclear-electric and some are dieselelectric. Any vehicle that combines two or more sources of power that can directly or
indirectly provide propulsion power is a hybrid.
The talk explains basic properties of reverberation chambers and presents some exemplary practical chambers with their parameters. The normative chamber validation as well as emission measurements and immunity tests are briefly explained. Finally, advantages and disadvantages are discussed.
HYBRID ELECTRIC VEHICLES
1. INTRODUCTION
A hybrid electric vehicle (HEV) has two types of energy storage units, electricity and fuel.
Electricity means that a battery (sometimes assisted by ultracaps) is used to store the energy, and that an electromotor (from now on called motor) will be used as traction motor.
Fuel means that a tank is required, and that an Internal Combustion Engine (ICE, from now on called engine) is used to generate mechanical power, or that a fuel cell will be used to convert fuel to electrical energy. In the latter case, traction will be performed by the electromotor only. In the first case, the vehicle will have both an engine and a motor.
Depending on the drive train structure (how motor and engine are connected), we can distinguish between parallel, series or combined HEVs.
Depending on the share of the electromotor to the traction power, we can distinguish between mild or micro hybrid (start-stop systems), power assist hybrid, full hybrid and plug-in hybrid.
Depending on the nature of the non-electric energy source, we can distinguish between combustion (ICE), fuel cell, hydraulic or pneumatic power, and human power. In the first case, the ICE is a spark ignition engines (gasoline) or compression ignition direct injection (diesel) engine. In the first two cases, the energy conversion unit may be powered by gasoline, methanol, compressed natural gas, hydrogen, or other alternative fuels.
Motors are the "work horses" of Hybrid Electric Vehicle drive systems. The electric traction motor drives the wheels of the vehicle. Unlike a traditional vehicle, where the engine must "ramp up" before full torque can be provided, an electric motor provides full torque at low speeds. The motor also has low noise and high efficiency. Other characteristics include excellent "off the line" acceleration, good drive control, good fault tolerance and flexibility in relation to voltage fluctuations.
The front-running motor technologies for HEV applications include PMSM (permanent magnet synchronous motor), BLDC (brushless DC motor), SRM (switched reluctance motor) and AC induction motor.
A main advantage of an electromotor is the possibility to function as generator. In all HEV systems, mechanical braking energy is regenerated.
The maximum operational braking torque is less than the maximum traction torque; there is always a mechanical braking system integrated in a car.
The battery pack in a HEV has a much higher voltage than the SIL automotive 12 Volts battery, in order to reduce the currents and the I2R losses.
Accessories such as power steering and air conditioning are powered by electric motors instead of being attached to the combustion engine. This allows efficiency gains as the accessories can run at a constant speed or can be switched off, regardless of how fast the combustion engine is running. Especially in long haul trucks, electrical power steering saves a lot of energy.
In this minute lecture, the main cost components of electricity are presented, demonstrating large variations in electricity cost across countries, and across market segments.
Embedded systems, especially in-vehicle embedded systems, are ubiquitously related to our everyday life. The development of embedded systems greatly facilitates the comfort of people’s life, changes our view of things, and has a significant impact on society
A Stirling engine is a heat engine that operates by cyclic compression and expansion of air or other gas (the working fluid) at different temperatures, such that there is a net conversion of heat energy to mechanical work. More specifically, a closed-cycle regenerative heat engine with a permanently gaseous working fluid.
The Stirling engine is noted for its high efficiency compared to steam engines, quiet operation, and the ease with which it can use almost any heat source.This engine is currently exciting interest as the core component of micro combined heat and power (CHP) units, in which it is more efficient and safer than a comparable steam engine.
Solar powered stirling engine driven water pumpeSAT Journals
Abstract Depletion of non-renewable resources has been a major problem that we face in today’s world, thus taking this into consideration, in this paper we deal with the powering of water pump using solar energy, for this purpose we use the principle of stirling cycle to achieve the desired result. Parabolic mirror is used to concentrate the solar beams onto the area where enough energy is produced to drive the stirling engine which works on the basic principal of the conversion of the heat energy to mechanical work depending on the heat difference being provided. A country like India, where energy crisis is a frequently observed problem, our system could be of great use especially in the areas where water deficiency is high, where shortage of electricity is a known fact. Our system uses the only abundant renewable energy that is the sun light for drawing out water from underground water beds which can be used to generate electric power, this method can act as an important tool. Keywords: Stirling engine, temperature difference, load, solar energy, water pump.
Dr. Keith Lovegrove unveiled the ANU's new solar thermal dish in September at the SolarPACES international solar thermal conference in Berlin to much acclaim. This will be the first time it will be presented in Melbourne.
It is the world's biggest solar dish that comes with a mass production system that can build one dish a day. The dish has the highest optical efficiency of any commercial solar technology in the world and a field of 500 produces 100MW electrical power. ANU's dishes can be used on undulating ground, which is difficult for current solar thermal systems that use mirror fields or troughs.
Dr. Keith Lovegrove will also talk about replacing all of Australia's energy needs with this solar technology used in conjunction with thermal salt storage.
Dr. Keith Lovegrove is a senior lecturer in Engineering in the Faculty of Engineering and Information Technology at the Australian National University (ANU). He heads the ANU Solar Thermal Group which works on a range of projects involving high and low temperature thermal conversion of solar energy. This includes looking at dish and trough concentrators and thermochemical energy storage. He is widely published in scientific journals and has advised the Australian Government on CSP . Dr Lovegrove and his team are at the forefront of International research into concentrated solar power.
Concentrated Solar Power Course - Session 3 : Central Receiver and Parabolic ...Leonardo ENERGY
Parabolic dishes
* general description
* main elements: parabolic concentrator, structure and tracking system, receiver, stirling engine and generator
* state of the art: types of dish-stirling systems; operational aspects; performance and economy
* future developments
Central receiver systems
* general description
* main elements: heliostat, tower, receiver, power conversion system
* state of the art: technology options; operational aspects; performance and economy
* future developments
Bulk Solar Power Generation :CSP and CPV technologiesLeonardo ENERGY
Thin film, silicon, concentrated solar power (CSP), concentrated photovoltaics (CPV), ... These are just some of the terms demonstrating that solar technologies are rapidly entering the electricity system in countries such as the United States, Spain or Australia. Furthermore, the largest improvements, which will bring generation cost closer to competitive prices are just around the corner.
This webinar is dedicated to utility scale and baseload solar technologies: CSP and CPV.
What is the status of these technologies, their improvement potential and perspectives for the future? What are the running projects and expectations in terms of market development? How is the levelized energy price expected to evolve in the near future to reach grid parity? Additionally, more practical aspects will be presented, as the conditions required by a CSP project to be viable or the keys to successfully finance the project.
After this briefing presentation, a discussion with participants will be launched on questions such as storage capabilities and system operation. Other questions from attendees are welcome to guide the discussion.
A OVERVIEW OF THE RANKIN CYCLE-BASED HEAT EXCHANGER USED IN INTERNAL COMBUSTI...IAEME Publication
The majority of the heat produced by automobiles, primarily by diesel engines, is squandered in various ways. If this waste heat is collected, it can be applied in a variety of other ways. Recently, increased emphasis has been placed on the global issue of rapid economic growth, a relative energy scarcity, internal combustion engine exhaust waste heat, and environmental degradation. The remaining heat is released into the environment through exhaust gases and engine cooling systems, leading to an increase in entropy and significant environmental pollution, so it is necessary to convert waste heat into useful work. Of the total heat supplied to the engine in the form of fuel, approximately 30 to 40% is converted into useful mechanical work. At 4000 RPM, the exhaust gas temperature is at its highest. So a recovery system is created for a constant RPM of 4000. A shell and tube heat exchanger and a uniflow steam engine connected to the main engine make up the recovery system. By reducing the frictional power at the main engine's power stroke and idle stroke, the linked steam engine increases the efficiency of the main engine. Due to the additional recovery system, the system's initial cost is significant. But over time, the system turns out to be profitable.
A sample of shoppers was selected and asked questions regarding co.docxannetnash8266
A sample of shoppers was selected and asked questions regarding consumer behavior. One of the questions asked was "Do you enjoy shopping for clothing?" Information regarding the responses is below:
· Total Responses: 500
· Males: 136 responded "yes" and 104 responded "no"
· Females: 224 responded "yes" and 36 responded "no"
Construct a contingency table summarizing the above results and answer the following questions:
1. What is the probability a shopper likes to shop for clothing?
2. Given a shopper is male, what is the probability the shopper likes to shop for clothing?
3. Given a shopper is male, what is the probability the shopper does not like to shop for clothing?
4. Given a shopper is female, what is the probability a shopper does not like to shop?
Renewable Energy 28 (2003) 873–886
www.elsevier.com/locate/renene
Technical and economical evaluation of solar
thermal power generation
Theocharis Tsoutsosa,∗, Vasilis Gekasb, Katerina Marketakib
a Centre for Renewable Energy Sources (CRES), 19th km Marathon Avenue, 19009 Pikermi, Greece
b Department of Environmental Engineering, Technical University of Crete, Crete, Greece
Received 23 July 2002; accepted 24 July 2002
Abstract
This article presents a feasibilty on a solar power system based on the Stirling dish (SD)
technology, reviews and compares the available Stirling engines in the perspective of a solar
Stirling system.
The system is evaluated, as a parameter to alleviate the energy system of the Cretan island
while taking care of the CO2 emissions. In the results a sensitivity analysis was implemented,
as well as a comparison with conventional power systems.
In the long-term, solar thermal power stations based on a SD can become a competitive
option on the electricity market, if a concerted programme capable of building the forces of
industry, finance, insurance and other decision makers will support the market extension for
this promising technology.
2002 Elsevier Science Ltd. All rights reserved.
Keywords: Technical and economical evaluation; Solar electricity generation; Solar thermal power; Stir-
ling engine
1. Introduction
The electrical generating demand has increased in the island of Crete due to the
economic growth during recent years. The rate of this increase becomes dramatical
during the summer. Conventional fossil fuel plants generate the electricity and this
∗ Corresponding author. Tel.:+30-1603-9900; fax:+30-1603-9904.
E-mail address: [email protected] (T. Tsoutsos).
0960-1481/03/$ - see front matter 2002 Elsevier Science Ltd. All rights reserved.
PII: S 0 9 6 0 -1 4 8 1 ( 0 2 ) 0 0 1 5 2 - 0
874 T. Tsoutsos et al. / Renewable Energy 28 (2003) 873–886
energy production cost is very high (Table 1); this cost can be higher in other Greek
islands [1].
The power generation should be increased over the next years in order to satisfy
the power demand. The new power plants should be environmentally since there
already exist some conventional foss.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Experimental Investigations on Solid Desiccant Cooling Systemijtsrd
Space cooling has become a necessity in present climatic conditions. A considerable fraction of today’s energy consumption is due to air conditioning of buildings, involving both heating and cooling. Maintaining comfortable indoor conditions in office building and industrial environments, it results higher energy bills due to heavy dependency on electrically operated air conditioning systems. Energy cost and environmental concerns force designers to find sustainable solutions. In order to explore ways and means to improve the energy efficiency and alternative energy resources, a feasibility study was conducted for combined cooling, heating and power system suitable for a tropical country This research has been conducted to evaluate the performance and applicability of desiccant cooling systems under Indian climatic conditions. The system has been analysed experimentally for the month of March and April. The performance of solid desiccant wheel at different rph rotation per hour was experimentally investigated in the month of March. The optimum speed for maximum value of average adsorption and regeneration rates was found to be 40 rph of both process and regeneration sectors. The variation of COP for the experiment has been analyzed with day time. It has been found that the COP ranges between 0.43 .54 for the months of March.OBJECTIVEThe aim of the experiments is to investigate the performance of a solid desiccant air conditioning system with a rotary desiccant wheel. Chandrashekhar Kumar | Prof. Ranjeet Arya "Experimental Investigations on Solid Desiccant Cooling System" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-6 , October 2020, URL: https://www.ijtsrd.com/papers/ijtsrd35821.pdf Paper Url: https://www.ijtsrd.com/engineering/mechanical-engineering/35821/experimental-investigations-on-solid-desiccant-cooling-system/chandrashekhar-kumar
OPTIMAL PLACEMENT OF DISTRIBUTED GENERATION FOR LOSS REDUCTION IN DISTRIBUTIO...ijiert bestjournal
Due to the increasing interest on renewable sources in recent times,the studies on integration of distributed generation to the power grid have rapid ly increased. Distributed generations (DGs) play an important role in distribution networks. Am ong many of their merits,loss reduction and voltage profile improvement can be the salient spec ifications of Distributed generations (DG). Non-optimal locations and non-optimal sizes of Dist ributed generations (DG) units may lead to increase losses,together with bad effect on voltag e profile. Proper location of Distributed generations (DGs) in power systems is important for obtaining their maximum potential benefits. Distributed generation (DG) units reduce electric p ower losses and hence improve reliability and voltage profile. Determination of appropriate size and location of Distributed generation (DG) is important to maximize overall system efficiency. In this project,Newton raphson method optimization technique has been presented to determ ine the appropriate size and proper allocation of Distributed generation (DG) in a dist ribution network.So,this project focus towards,at determining optimal DG allocation and s izing as well as analyzing the impact of Distributed generation (DG) in an electric power sy stem in terms of voltage profile improvement and line loss reduction
Analysis and Design Methodology for Thermoelectric Power Generation System fr...Omkar Kamodkar
This paper combines heat transfer and
thermoelectric conversion techniques to create a
thermoelectric generator device for a single-cylinder, fourstroke petrol engine. The system is made up of heat absorbers,
thermoelectric generator, Thermoelectric Generator (TEG)
modules, and an external heat sink. To achieve the goal of
absorbing heat and increasing thermoelectric conversion
efficiently, the heat exchanger surface area and heat-exchange
time could be increased. Thermoelectric generators convert
waste heat into energy directly. This technology will also help
energy conversion systems work better overall. Despite the
fact that TEG production is limited by available technologies,
feasible electricity generation is possible from waste heat
generated by automobiles. The effect of using passive heat
sinks and heat absorbers made of a flat plate with fins of
various cross-sectional areas and materials with forced
convection heat transfer, as well as how current, voltage, and
power are varied, is investigated and presented in tabular
format in the current numerical analysis. By plotting the
results of the analytical and numerical method on relevant
graph, the results of both methods were compared
Modelling, Fabrication & Analysis of Pelton Turbine for Different Head and Ma...ijceronline
India is a country with huge population and variety of geographical locations. It has many places where high altitude mountains are present and have potential to generate the electricity through Hydro power plants. For high head power projects Pelton turbine is the first choice for the alternators. As he Efficiency is better in the above turbine as the research and the previous study has shown. The material by which the turbine is constructed matters a lot in achieving speed as well as efficiency of the entire system Here an attempt is to model construct the design the Pelton wheel turbine for such high altitude areas on Indian subcontinents especially in north and north east part of the country, some places in Madhya Pradesh may also discovers with such location to create micro hydel power plants. The present work is a combination of mathematical modeling, fabrication of the proposed work, its Drafting and analysis using Creo & ANSY Work bench 12.0 and ultimately forecasting of speed and efficiency using artificial neural network
IRJET- Performance and Evaluation of Aqua Ammonia Air Conditioner System ...
An analysis of beta type stirling engine with rhombic drive mechanism
1. Renewable Energy 36 (2011) 289e297
Contents lists available at ScienceDirect
Renewable Energy
journal homepage: www.elsevier.com/locate/renene
An analysis of beta type Stirling engine with rhombic drive mechanism
D.J. Shendage a, S.B. Kedare a, S.L. Bapat b, *
a
Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
b
Department of Mechanical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
a r t i c l e i n f o a b s t r a c t
Article history: Stirling engine system is one of the options for electrifying a remote community not serviceable by the
Received 27 October 2009 grid, which can operate on energy input in the form of heat. Major hurdle for the wide-spread usage of
Accepted 28 June 2010 rhombic drive beta type Stirling engine is complexity of the drive and requirement of tight tolerances for
Available online 24 July 2010
its proper functioning. However, if the operating and geometrical constraints of the system are accounted
for, different feasible design options can be identified. In the present work, various aspects that need to
Keywords:
be considered at different decision making stages of the design and development of a Stirling engine are
Stirling engine
addressed. The proposed design methodology can generate and evaluate a range of possible design
Rhombic drive
Overlapping volume
alternatives which can speed up the decision making process and also provide a clear understanding of
the system design considerations. The present work is mainly about the design methodology for beta
type Stirling engine and the optimization of phase angle, considering the effect of overlapping volume
between compression and expansion spaces. It is also noticed that variation of compression space
volume with phase angle remains sinusoidal for any phase difference. The aim of the present work is to
find a feasible solution which should lead to a design of a single cylinder, beta type Stirling engine of
1.5 kWe capacity for rural electrification.
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction be cheaper compared to solar photovoltaic units for 1.5 kWe capacity.
There are 96,000 villages in India to be electrified [1]. Of these more
Stirling engines are again becoming relevant due to shortage and than 20,000 villages are in remote and difficult areas of the country,
high cost of fossil fuel. Stirling engines can run quietly on combus- 3e30 km away from grid, with number of households below 200,
tion of any fuel. These do not use valves and are generally compact average population less than 500, with time for power requirement
and reliable, as combustion takes place outside the working space. quite low (of the order of 4e6 h/day) for minimal facilities. The grid
Stirling engines also do not have the Ozone depletion potential. connection for such villages is a very costly proposition and hence not
Stirling engines work on Stirling cycle and have high efficiency. The easily taken up. Therefore, a Stirling engine with capacity of about
ideal Stirling cycle consists of two isothermal and two isochoric 1.5 kWe seems to be the most viable option. It will, at least partially,
processes as depicted on PeV diagram in Fig. 1. The cycle operates help to overcome the present problem of scarcity of electrical energy
between minimum and maximum temperatures, TC and TE. The limit in India, especially in remote regions. If biomass or agricultural waste
on TE is dependent on the material of construction for the system. is available as fuel many more applications may come up at small
The regenerator is a thermodynamic sponge, a porous mass of finely companies and communities [2].
divided material and alternately accepts (process 4e1) and rejects Stirling engines of various configurations are developed over the
(process 2e3) heat from working fluid as shown in Fig. 1. years. Also different analysis methodologies are used for the
Since Stirling engines are external heat source engines, they can purpose of analysis and comparison between systems. Shoureshi
also operate on concentrated solar energy and any gaseous or liquid has compared Stirling, Rankine and Brayton engines at different
fuels. practical temperature-ratios conditions and shows that Stirling
Thermal efficiency of Stirling engine is expected to be higher than engines are more efficient than others [3]. The “V”-type Stirling
that of Rankine cycle based systems. Stirling engine may also prove to engines with sealed and dry crank-cases and fuelled by natural gas
are presently under development at the Physical-Technical Institute
and one of the major issues in improving kinematic Stirling engine
performance was proper guiding of piston rings, while developing
* Corresponding author. Fax: þ91 22 25 72 68 75.
E-mail addresses: shendagedj@iitb.ac.in (D.J. Shendage), sbkedare@iitb.ac.in
Radioisotope Stirling engines [4]. In other words, one has to design
(S.B. Kedare), slbapat@iitb.ac.in (S.L. Bapat). drive mechanism such that it should have minimum side thrust and
0960-1481/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.renene.2010.06.041
2. 290 D.J. Shendage et al. / Renewable Energy 36 (2011) 289e297
and schematically has simple arrangement. In beta configuration,
both displacer and cylinder are accommodated in same cylinder and
1-2: Heat rejection at TC has comparatively complex arrangement. Gamma configuration
3 Isothermal 2-3: Heat added by includes displacer and piston in separate cylinders and has simple
expansion regenerator arrangement. Though beta configuration is complex, it has merit
3-4: Heat addition at TE
4 over other types due to its ability to provide overlapping volume. The
4-1: Heat rejected by
regenerator beta machine can have almost 30% larger heat exchangers than that
Pressure
for gamma machine for the same compression ratio [6]. In short, beta
engine is selected due to its advantages like compactness, lower
2 Isothermal dead space involved and overlapping of volume.
compression The studies were carried out for different configurations,
1 working fluid and heat sources. Miyabe et al. conducted various
experiments on alpha type, Nitrogen charged, kinematic Stirling
Volume engine using crank mechanism with phase angle 90 and proposed
design method for regenerator matrix [7]. Erich selected the a-type
Fig. 1. Ideal Stirling cycle with complete regeneration. Stirling engine with crank mechanism due to cost reasons. Air or
jerky moment. The prime motivation for carrying out the present nitrogen as working fluid and many parts from industrial mass
work was (i) to investigate the methodology for kinematic analysis, production had been used for development [2]. Biedermann et al.
and (ii) to link kinematic analysis to the thermodynamic cyclic has developed 35 kWe pilot plant with more than 5000 h of
analysis, so that the mechanical phase angle, geometrical and successful operation utilising wood chip fuels with overall electric
operating parameters can be optimised. The paper addresses efficiency 9.2% [8]. The engine uses, Helium as working fluid at
various aspects that need to be considered at different decision 4.5 MPa mean pressure, the crank mechanism operating at
making stages of the design and development of Stirling engine. 1010 rpm and has four cylinders and looking for improved reli-
The rhombic drive mechanism chosen for the present work is ability of driving mechanism. Thomas et al. have compared four
analysed and designed in detail. The design methodology is Dish-Stirling systems, named as Sun Dish, Euro Dish, SES and WGA,
proposed that will help in optimising Stirling engine. It is intended which are developed for commercial applications [9]. The highest
to exploit the advantage of overlapping volume to the fullest extent. overall efficiency of the solar power generation system is nearly
The objective of the present work is to analyse the rhombic drive by 30% and the issues for commercialising are cost and reliability
considering different aspects which include [9,10]. TEDOM Company developed the functional prototype of
kinematic Stirling engine, which has output of 7.9 kW at 1500 rpm
(1) selection of configuration of Stirling engine, with engine efficiency of 24.13% at 670 C/50 C temperatures at
(2) design consideration in rhombic drive from assembly point of 11.2 MPa mean pressure of helium [11]. They observed that reli-
view, analysis of beta type engine with rhombic drive i.e. ability of piston ring matters for long running of life and can be
calculation of stroke, calculation of phase angle, selection of increased by proper design and selection of drive mechanism. Halit
relative eccentricity ratio (3), calculation of overlapped volume, et al. analysed and tested a beta type Stirling engine with a lever
(3) mechanical design of rhombic drive by considering torque on controlled displacer driving mechanism, with pressurised crank-
crankshaft and buckling of piston rods and displacer rod and case kinematic and thermodynamics points of view [12e14]. The
(4) methodology to link the thermodynamic analysis and rhombic engine developed by Halit et al. is water cooled with helium
drive analysis with limitations and challenges in rhombic drive. charged and produces 183 W at 590 rpm [12]. It can be noticed that
main challenges to develop reliable engine, are sealing of working
fluid at high pressures and design of drive mechanism with
minimum side thrust.
2. Selection of configuration of Stirling engine and drive Can has analysed and developed a beta type Stirling engine
mechanism using crank mechanism with air as working fluid at atmospheric
pressure [15]. The same is cooled by water and has 90 phase angle
As shown in Fig. 2, three configurations, namely the alpha, beta and produces 5.98 W at 208 rpm with the hot-source temperature
and gamma configurations, are commonly used in Stirling engine of 1000 C. Youssef et al. have developed model considering ther-
[5]. Alpha configuration includes two pistons in separate cylinders modynamic analysis and can be useful to understand the influence
of various geometrical and operating parameters for beta type
Stirling engine [16]. Similarly, it is needed to develop methodology
for the kinematic analysis of rhombic drive, which will consider
effect of acceleration of links, and will able to couple with ther-
modynamic analysis. Hence, the designed engine will have long life
with reliability. Mirunalini et al. have numerically analysed
performance of a beta Stirling solar thermal engine system [17]. It
can be observed that phase angle and regenerator volume plays
vital role in engine performance [17,18]. But in beta type Stirling
engine with rhombic drive mechanism, one can make use of
overlapping volume in compression space and modify the
mechanical phase angle for more power output with negligible
sacrifice in efficiency.
It is clear from the above-reported studies that the requirement
is of a reliable (with high reproducibility), long life engine with high
specific power output and low fuel consumption presently. The
Fig. 2. Three basic mechanical configurations for Stirling engine. drive mechanism has to be capable of providing the reciprocating
3. D.J. Shendage et al. / Renewable Energy 36 (2011) 289e297 291
motion to both; the piston and the displacer; and simultaneously reciprocating motion to the piston (1). Similar to piston, the con-
ensure the desired phase difference between their motions. There necting rods (9 and 9’) of equal length provide the link between the
are three different considerations for selecting a suitable drive cranks (5 and 5’) and the displacer yoke (8). If the two pairs of con-
mechanism for a Stirling engine. The first is to choose a mechanism, necting rod i.e. 4, 4’ and 9, 9’ are made of identical lengths, they will
which will carry the working gas through the cycle and provide the form a rhombus. The name rhombic drive is for this reason.
desired level of work output based on the heat input. The second The displacer rod (7), connecting the displacer (6) to displacer
consideration is mechanical efficiency, which means that the yoke (8) has to pass through the piston 1 and also the compression
mechanism should have low frictional losses. The third consider- space formed between the top surface of the piston and the bottom
ation is the practical aspect such as the size, reliability and cost. surface of displacer. It needs to be noted that the volume of
Rhombic drive mechanism is chosen with clear expectation that all compression space varies due to movement of not only the piston but
the three criteria as above will be satisfied. Beta engine with also the displacer. However, the expansion space varies over a cycle
rhombic drive gives minimum side thrust, ensures silent working of only due to movement of the displacer. This movement of displacer
engine. On analysis of the drive mechanisms viz., crank drive and rod through the piston needs a proper sealing arrangement as
rhombic drive, it was found that the rhombic drive mechanism provided by bush (11). One of the shafts is generally used for cranking
gives a maximum power output 10% higher than the crank drive during ‘start up’ and the other shaft is used to provide energy output.
mechanism whereas its thermal efficiency is about 0.5% lower [19].
3.1. Design considerations in rhombic drive from assembly point of
view
3. Beta type engine with rhombic drive
1) There are two ways of fixing the connecting rods on the crank
Rhombic drive was originally developed around 1900 for the twin-
pins shown in Fig. 4 as (a) Spilt connecting rod for piston yoke
cylinder Lanchester car engine where it allowed perfect balancing of
and (b) spilt connecting rod for displacer yoke [19]. The spilt
the inertial forces on both pistons [20]. The rhombic drive mechanism
connecting rod for piston arrangement has been chosen
for Stirling engine was invented by Meijer of Philips, Holland in 1959
because of the following reason:
and used it extensively for beta type engines [19]. Fig. 3 shows the
(i) From assembly point of view, it is easy to assemble/
schematic diagram indicating the arrangement of components and
disassemble.
the linkages used to provide reciprocating motion without side thrust
(ii) Gas forces on piston links will be higher than that of dis-
for both, the piston (1) and the displacer (6). The two spur gears (10
placer. It will ensure safety from mechanical design point of
and 10’) mesh together and rotate in opposite directions as shown in
view.
Fig. 3. The whole arrangement is symmetric with respect to center line
2) Arrangement of linking piston and piston yoke (upper arm) can
of the piston as well as the displacer. The two cranks (5 and 5’) are of
be achieved by two methods (a) Piston and two solid piston
equal length r. Connecting rods (4 and 4’) of equal length provide the
rods arrangement and (b) Piston and annular piston rod
link between the crank and the piston yoke (3). Piston rod (2)
arrangement. Arrangement with two solid piston rods (Fig. 5
connects the piston yoke (3) with the piston (1) and thus provides the
(a)) is adopted. It serves following purposes:
(i) Confirmation of piston in horizontal plane during assembly.
(ii) It provides ease in piston seal assembly and inspection.
Piston rods can be integral part of piston.
3) Alignment of crankshafts (Fig. 3) plays vital role in smooth and
quiet running of the drive assembly. Gearwheels (10 and 10’)
ensure exact symmetry of the system at all times. The two
crankshafts being geared together, the entire shaft output can
be taken off from either of them. Although the gears are
completely reliable, they tend to be subjectively noisy when
compared to the overall quietness of the rest of Stirling engine.
The gear noise can be reduced by reducing module of spur gear
or using backlash free gearwheels.
3.2. Analysis and design considerations in rhombic drive
The special form of the rhombic drive mechanism is derived
from the general form by excluding link between crank pin and
Fig. 3. Schematic of Stirling engine with the rhombic drive mechanism. 1: Piston; 2:
Piston rod; 3: Piston yoke; 4, 4’: Connecting rod (for piston yoke); 5, 5’: Crank; 6:
Displacer; 7: Displacer rod; 8: Displacer yoke; 9, 9’: Connecting rod (for displacer
yoke); 10, 10’: Spur Gears; 11: Bush, 12: Regenerator, 13: Multiple heater tubes, 14:
Connecting duct, 15: Expansion space, 16: Compression space, 17: Cylinder head, 18:
Crankcase, 19: Cooler, 20: Coolant. Fig. 4. Spilt connecting rod for piston yoke for rhombic drive mechanism.
4. 292 D.J. Shendage et al. / Renewable Energy 36 (2011) 289e297
Fig. 5. (a) Piston and two piston rod arrangement (b) Piston and annular piston rod arrangement.
connecting rod and swivel joint, resulting in equal displacer and the 1 X
N
cos c ¼ Bn cosðnjÞ (3)
piston strokes as shown in Fig. 6 [19]. Analysis of rhombic drive l n¼0
includes determination of stroke, phase angle and overlapping
volumes for particular dimensions of crank length r, connecting rod where,
length (L) and eccentricity (e). J ¼ 0, when both cranks are in same line and face each other, and
c ¼ angle which the piston connecting rod makes with x-axis as
3.2.1. Calculation of stroke shown in Fig. 6.
The stroke of the piston is equal to that of the displacer, because of The coefficient B1 as function of l and 3 can be calculated [19].
the symmetry of the rhombic drive about y-axis as shown in Fig. 6. Then, one can calculate, Phase angle (a) ¼ 2 tanÀ1(B1).
The displacer is in its lowest position when the displacer connecting
rod and crank are in one straight line and its top position when 3.2.3. Selection of relative eccentricity ratio (3)
displacer connecting rod covers the crank [19]. It follows that, In present analysis relative eccentricity ratio (3) is selected as 1.5
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi due to following reason:
S 1
ð1 þ lÞ Àl 32 À ð1 À lÞ Àl 32
2 2 2 2
¼ (1) As relative eccentricity ratio, 3 increases, buckling force on
r l
connecting rod increases. This happens because the value of
where, acceleration for the whole mechanism increases. Thus, though
power output is increasing as relative eccentricity ratio increases,
Eccentricity ratio ¼ 3 ¼ e=r ð3 1Þ its value is to be restricted. Based on the data available for two
manufactured units with rhombic drive (Table 1), we also
and l ¼ r=L ðe þ rÞ L
considered eccentricity ratio only up to 1.5 in present work.
Thus, stroke can be calculated by using simple relation, having 3
and l as variables. 3.2.4. Calculation of overlapped volume
Overlap volume is the volume of cylinder which is used both
3.2.2. Calculation of phase angle by the movement of the displacer and the piston as shown in
For the purpose of analysis, the cycle is combined to be split into Fig. 7 (a).
a large number of equal intervals. The start of the cycle, for which Modeling the expansion space height Hexp, from Fig. 7 (b) we
the crank angle (F) should be 0 is the top most position of the get,
displacer. Thus, at crank angle 0 , the expansion space volume is
the minimum. Next, the value of crank angle when the piston will Hexp ¼ ðhe À hc Þ À r$sin a1 þ L$sin b1 (4)
be in top most position is determined, knowing the various Similarly, for compression space height Hcomp
parameters. This will be the difference in motion between displacer
and piston when the displacer leads the piston motion. Hcomp ¼ ðhc À h2 À h1 Þ À 2L$sin b1 (5)
For ease of calculations (particularly for forces calculations)
modified crank angle (j) is defined on basis of crank position for Also, from geometrical constraints,
drive analysis. It is zero (00) when cranks are horizontal with inward
e ¼ r$cos a1 þ L$cos b1 ¼ constant (6)
position. Hence,
0 1
Angle difference between crank at
Modified crank angleðJ½iŠÞ ¼ F½iŠ þ @ displacer TDC position and A (2)
horizontal position
Meijer [19] has given numerical solution which uses series expansion Now, using the fact that,
of cos(nj). The sign convention for X is shown in Fig. 6. The abscissa of Minimum{Hexp} ¼ Minimum{Hcomp} ¼ 0, and using above three
the displacer yoke is xd and that of the piston yoke is xp. Then, we have, equations, eliminating constants [22], we finally get,
5. D.J. Shendage et al. / Renewable Energy 36 (2011) 289e297 293
Fig. 6. Special form of rhombic drive obtained from general form [19].
rffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
e 2
Hexp ¼ ÀðL À rÞ 1À À r$sin a1 þ L$sin b1 (7)
LÀr
and,
2sffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 3
2
Hcomp ¼ 2L 4 1À eÀr À sin b1 5 (8)
L
The overlap length, as can be seen from Fig. 7(a and b), can be
written as,
È É
OHmax ¼ Maximum Hexp þ h1
È É
À Minimum Hexp þ Hcomp þ h1
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi'
OHmax ¼ 2 ðr þ LÞ2 Àe2 À L2 À ðe À rÞ2 (9) Fig. 7. (a) Overlap volume region. (b) Terminology for analysis of overlap volume.
where, OHmax ¼ Maximum overlapping height Considering above aspect, maximum overlapping height is
which is again obtained by using previous equation. Values of r, restricted only to 0.55 times of stroke for further analysis.
L and e have to be chosen such that we get maximum possible
overlap ensuring that the cylinder volume is properly utilised. OHmax
i:e: z0:55 (11)
It is observed that for particular value of set of phase angle S
(78.5 ), maximum overlapping stroke is 0.596 times stroke. During
For further analysis, overlapping volume and clearance volume
operations some wear is expected. This can cause a play in bushes
can be evaluated as follows,
at crankshafts, crank pins, connecting rods, displacer yoke and
piston yoke. To account for these, clearance is provided in between p
piston and displacer. This clearance is calculated using the Vdiscle ¼ ðddis Þ2 *CLmin (12)
4
following relationship.
! pÀ Á
S Vpiscle ¼ dpis À ddisrod *CLmin (13)
CLmin ¼ 0:005x þ 0:5 =1000 (10) 4
1000
p
VpisOVERLAPPING ¼ d2 À d2
pis disrod *ðOverlapping lengthÞ (14)
4
where,
Table 1
Vdiscle ¼ Displacer clearance volume
Major dimensional data for the rhombic drive for the two engines (Mean pressures
are different for engines). VpisOVERLAPPING ¼ Overlapping volume
30 kW, Beta type, 3 kW, GPU-3
Meijer’s engine [19] Engine [21] 3.3. Mechanical design of rhombic drive
r  102 (m) 2.65 1.397
e  102 (m) 3.92 2.065 In the present case, the stroke of piston is equal to that of the
L Â 102 (m) 8.8 4.602 displacer, because of the symmetry of the rhombic drive about the
e/r 1.4792 1.478 vertical axis. The displacer is in its lowest position (BDC) when
L/r 3.32 3.294
the displacer connecting rod forms a continuation of the crank. And
6. 294 D.J. Shendage et al. / Renewable Energy 36 (2011) 289e297
it is at top position (TDC) when the displacer connecting rod covers
1
(coincides with) the crank. For analysis and mechanical design of Fp3 ½iŠ ¼ Fp ½iŠ À mo €i sec c
xpis (18)
2
Rhombic drive first step to follow is to determine stroke (S), angle
with vertical axis (X) at various crank angle (F) with use of Eqs. (1)
Fp4 ½iŠ ¼ 0 (19)
and (2). Then, calculate torque on crankshafts due to the gas forces
and inertia forces as discussed below. apc 2
Fp5 ½iŠ ¼ Fp3 ½iŠsinðc½iŠ À j½iŠÞ À mpc 1 À ru (20)
3.3.1. Calculation of torque on crankshaft L
The calculation of the torque is based on the energy balance of the
engine. The rhombic drive is symmetrical at any instant during oper- Fp ½iŠ ¼ Fp3 ½iŠcosðc½iŠ À j½iŠÞ (21)
ation. It is assumed that the drive is completely balanced. Hence, half of
Similarly, forces on displacer drive linkages for ith interval are:
the rhombic drive mechanism is considered for analysis. Various
forces and moments occurring in the rhombic drive mechanism are 1
shown in Fig. 8. Resultant torque on crankshaft is summation of torque Fd1 ½iŠ ¼ À Fd ½iŠ À md €i
xdis (22)
2
due to gas forces, inertia forces and friction, and is evaluated as:
P
_
1 xp 1 xd _ Pf E d
Tt ¼ Fp þ F À À (15)
|{z} 2 u 2 du
|fflfflfflfflfflfflfflfflfflfflffl{zfflfflfflfflfflfflfflfflfflfflffl}u
|{z} dj
Resultant |fflffl{zfflffl}
Torque due to gas forces Torque due to Torque due to inertia
torque
of circuit and crankcase friction forces
1
Different torques considered to calculate resultant torque are as Fd2 ½iŠ ¼ À Fd ½iŠ À mo €i tan c
xdis (23)
follows: 2
1
1. Torque due to gas forces on piston: It is resultant of forces due Fd3 ½iŠ ¼ À Fd ½iŠ À mo €i sec c
xdis (24)
to working space pressure and buffer/crankcase pressure acting 2
on the piston itself and crankcase pressure acting on piston rod.
2. Torque due to gas forces on displacer: The gas force on the Fd4 ½iŠ ¼ 0 (25)
displacer is due to the pressure difference between the
a
expansion space and compression space, which is caused by
Fd5 ½iŠ ¼ Fd3 ½iŠsinðc½iŠ þ j½iŠÞ À mdc 1 À dc r u2 (26)
flow resistance in heat exchangers and by the force on displacer L
rod caused by pressure in the working space and in crankcase.
3. Torque due to inertia forces: It depends on speed and masses of Fd6 ½iŠ ¼ Fd3 ½iŠcosðc½iŠ þ j½iŠÞ (27)
rotating gearwheels and reciprocating components in engine
assembly. Data is generated for calculating masses of components. F7 ½iŠ ¼ Fp3 ½iŠsinðc½iŠ À j½iŠÞ þ Fd3 ½iŠsinðc½iŠ þ j½iŠÞ þ mo r u2 (28)
4. Torque due to friction: It requires knowledge of the coefficient
of friction of piston and bearings, which is largely lacking since
these variables depend on a large number of factors. From
F8 ½iŠ ¼ Fp3 ½iŠcosðc½iŠ À j½iŠÞ À Fd3 ½iŠcosðc½iŠ þ j½iŠÞ (29)
experience of IC Engines, generally torque due to friction is not
iþ2 #,
major share on crankshaft. However, the total power of a well sdpis þ sdiþ1
pis sdiþ1 þ sdi
pis pis
built Stirling engine is only about 10% of the power delivered by xiþ1
_ pis ¼ À ðInterval timeÞ (30)
2 2
the engine [19]. In present work, frictional power in drive
mechanism and engine subassemblies is considered as 15% of #,
power developed by the engine. sdiþ2 þ sdiþ1 sdiþ1 þ sdi
xiþ1
_ dis ¼ dis dis
À dis dis
ðInterval timeÞ (31)
2 2
The formulae given below are used in programming to calculate
forces on different linkages. It is assumed that connecting rods are h i.
replaced by weightless rods and with certain masses at ends having
€iþ1 ¼ xiþ1 À xi
xpis _ pis _ pis ðInterval timeÞ (32)
certain moments of inertia [19]. However, calculation of torque due
to inertia forces does not give actual force distribution along con- h i.
€iþ1 ¼ xiþ1 À xi
xdis _ dis _ dis ðInterval timeÞ (33)
necting rods but a mean value, which is sufficient for the strength
calculations. For analysis the forces on the piston drive mechanism
for the ith interval are, p p p
Fd ½iŠ ¼ d2 Pexp ½iŠ À
dis d2 À d2 Pcomp ½iŠ À d2 Pavg
4 4 dis disrod 4 disrod
1
Fp1 ½iŠ ¼ Fp ½iŠ À mp €i
xpis (16) (34)
2
1
p p 2
Fp2 ½iŠ ¼ Fp ½iŠ À mo €i tan c
xpis (17) Fp ½iŠ ¼ d2 À d2
pis
2
disrod Pcomp ½iŠ À 4 dpis À ddisrod Pavg (35)
2 4
7. D.J. Shendage et al. / Renewable Energy 36 (2011) 289e297 295
UO ¼ ðEmax Þ À ðEmin Þ (39)
3.3.2. Design for buckling of piston rods and displacer rod
In present work, two piston rods are provided. Hence, the critical
load will be shared by both piston rods equally. The maximum force
on piston Fp[i] is calculated for particular set of operating conditions.
Assuming factor of safety, length of rod and diameter of rod is
calculated using Johnson and Euler’s theory for buckling of rod [23].
Simultaneously this procedure is extended for displacer rod by using
maximum force on displacer rod for same set of operating conditions.
3.4. Methodology to link the thermodynamic analysis and rhombic
drive analysis
1. The procedure takes into account all constraints discussed
above. Initially, by using Beale number, average pressure and
using bore to stroke ratio, stroke length is calculated. Eccen-
tricity ratio (3) is iterated such that it satisfies l 1.5 to calcu-
late prescribed stroke.
2. One cycle of operation is divided into large intervals. For each
interval compression space height (Hcomp) and expansion space
height (Hexp) is calculated. It is also ensured that mechanism
operates within the geometrical constraints.
3. Overlapping volume, compression space and expansion space
live volumes are calculated for each interval. These volumes are
input for cyclic analysis of Stirling engine.
4. Piston and displacer velocities are calculated using displacement of
respective links and interval time for a given speed i.e. 1440 rpm. It
makes possible to use generator on same shaft of the engine.
5. Then, phase angle of engine is optimised on basis of maximum
net brake power of engine.
6. Various forces and moments occurring in the rhombic drive
mechanism are calculated by using energy balance and link
velocities. Resultant torque is summation of all torques on
crankshaft.
3.5. Limitations and challenges in rhombic drive
Usage of rhombic drive Beta type Stirling engine is presently
Fig. 8. Various forces and moments occurring in the rhombic drive mechanism [19]. quite restricted due to the drive’s complexity and requirement of
tight tolerances for its proper functioning. If during the operation
Tt[i] is torque on crankshaft at particular crank angle, can be there is an unsymmetrical wear of the pins or joints of the drive
calculated using above equations. Average torque throughout arrangement then it could lead to severe damage to the engine
interval Ttavg ½iŠ can be calculated as, [6,24]. It involves large no. of moving parts in the assembly, which
could again lead to wear and tear of various rubbing parts.
Tt ½i þ 1Š þ Tt ½iŠ Some demerits of Beta engine which can be overcome by
Ttavg ½iŠ ¼ (36)
2 advancement of technology are discussed below.
Energy output throughout interval E[i] can be calculated as,
a) These designs are complex to construct as to fit both the dis-
E½iŠ ¼ Ttavg ½iŠ*dj (37) placer and the piston in one cylinder. And it requires a high
quality of precision fit to be done.
Mean torque ðTtmean Þ throughout the cycle can be calculated as,
b) Piston seal leakage depends on clearance between piston bush
P and displacer rod. And it is difficult task to maintain appro-
E½iŠ
Ttmean ¼ P (38) priate clearance in running condition for long time as both are
dj
continuously moving. Hence, alignment during drive assembly
By using Ttavg ½iŠ variation of torque with crank angle is plotted. This should be done with almost care. Use of different fixtures will
is known as turning moment diagram. From graph maximum help a lot.
energy point and minimum energy point can be calculated by using c) Major reason for vibrations during operation is jerky motion of
Eq. (39). Hence, flywheel can be designed by considering two links. It can be controlled by suitably selecting crank radius,
different basis: i) on basis of energy released, coefficient of fluctu- eccentricity and length of connecting rod dimensions. From
ations (Cf), mass moment of inertia, density of gear material, table provided for different eccentricity ratio (B1) values by
module and pitch circle diameter of gear. ii) on basis of starting Meijer [19], it is observed that B1 should be less than 1.5 to
torque to ensure sufficient strength. avoid jerking motion.
8. 296 D.J. Shendage et al. / Renewable Energy 36 (2011) 289e297
50
Mass of piston = 1.1 kg
Resultant torque
Expansion space curve 40
Mass of displacer = 1.1 kg
Mean pressure = 24 bar
Speed = 1440 rpm Torque due to
30 Working fluid = Hydrogen gas forces
3
Volume, m
Torque, N.m
20
0 Tmean = 7.35 N.m
180 127.5, 20.3
Compression space curve 10
0
0 30 60 90 120 150 180 210 240 270 300 330 360
o
-10
Crankangle,
Torque due to mass inertia 260, -7.5
Fig. 9. Expansion and compression volume variations. -20
0 30 60 90 120 150 180 210 240 270 300 330 360
0
d) Backlash in gear and bearing clearance creates vibrations in Crank angle (ψ ),
machine. But in present case forces on teeth at running
Fig. 11. The torque due to gas forces (working spaces) and torque due to the inertia
condition are at same direction. Engine operation depends on
(constant angular velocity) on one crankshaft at 24 bar mean pressure.
smooth operation of drive and gear assembly.
It can be seen from Fig. 11 that torque due to gas forces has
4. Results and discussion major contribution in resultant torque.
i) On analysis of the drive mechanisms viz., crank drive and
rhombic drive, it was found that the rhombic drive mecha-
nism gives a maximum power output 10% higher than the 5. Conclusions
crank drive mechanism whereas its thermal efficiency is
about 0.5% lower. In the present work, rhombic drive mechanism for Stirling engine
ii) Fig. 9 shows volume variation of non-sinusoidal motion with application is analysed. The present work is mainly about the design
respect to crank angle. At crank angle equal to zero, displacer is procedure for beta type Stirling engine and the optimization of
at TDC position and we will get maximum compression space phase angle, considering the effect of overlapping volume between
volume at particular instant. As shown in Fig. 9, maximum compression and expansion spaces. Methodology to link the ther-
average pressure intervals and overall time achieved for modynamic analysis and rhombic drive analysis is also reported.
expansion is more by this configuration. Expansion takes place Major conclusions from the present work are listed below:
from 0 to 212.5 crank angle (i.e. approximately 60% of total
cycle interval). Hence power output increases. Fig. 10 shows 1. As eccentricity ratio increases, it will enhance the power
stroke (S) variation of non-sinusoidal motion with respect to output. Simultaneously, it will demand for increase in con-
crank angle. Theoretically, maximum overlapping stroke can necting rod length. Then, buckling problem will become
be achieved is 0.596 times the stroke of displacer or piston. predominant. It will result into an unsymmetrical wear of the
iii) It is also noticed that compression space volume curve pins or joints of the drive arrangement during the operation.
remains sinusoidal for any phase difference. To increase dis- Then, it could lead to severe damage to the engine. Hence,
placer dwelling period at compression piston and increase in eccentricity ratio for rhombic drive mechanism is fixed as 1.5.
overlapping volume one can think of shifting of compression 2. It is also noticed that variation of compression space volume
curve towards left. But it is not recommended because indi- with phase angle remains sinusoidal for any phase difference. It
rectly length of connecting rod has to increase and accelera- improves power output (by around 10%) compared to crank
tion of links will increase. It will cause buckling of connecting driven beta Stirling engine for same geometrical and operating
rods and its intensity will be higher due to cyclic stresses. parameters.
iv) Fig. 11 shows torque variation due to gas forces and mass 3. It discusses about various aspects to be considered in rhombic
inertia forces for 1500 We engine at designed conditions. drive by assembly point of view e.g. assembly of connecting
rods and piston rods.
TDC-Displacer 4. The effect of displacer and piston mass, connecting rods and
yokes is considered along with pressure forces in working
spaces for plotting the turning moment diagram. It also gives
TDC-Piston
basis for flywheel design.
Overlapping 5. Present work gives design methodology for beta type Stirling
Stroke, m
length engine and optimization of phase angle considering effect of
BDC-Displacer overlapping volume.
6. The proposed design methodology can generate and evaluate
a range of possible design alternatives which can speed up the
BDC-Piston decision making process and also provide a clear under-
-50 0 50 100 150 200 250 300 350 400
standing of the system design considerations. The aim of the
0 present work is to find a feasible solution which should lead to
Crank angle,
a design of a single cylinder, beta type Stirling engine of 1.5 kWe
Fig. 10. Stroke variations of piston and displacer. capacity for rural electrification.
9. D.J. Shendage et al. / Renewable Energy 36 (2011) 289e297 297
Acknowledgement 3: Eccentricity ratio, e/r
F: Crank angle, radian
The authors acknowledge the financial support from Ministry of c: Angle which the piston connecting rod makes with X-axis,
New and Renewable Energy, Government of India, to carry out the radian
present work. u: Angular velocity, rad/sec
b1: Angle which the piston connecting rod makes with X-axis,
Nomenclature radian
a1: Angle which the crank makes with Y-axis, radian
adc: Distance from center of big end connecting rod of displacer
and center of gravity of displacer connecting rod, m Subscripts
apc: Distance from center of big end connecting rod of piston and avg: Average
center of gravity of displacer connecting rod, m cle: Clearance
B1: Expansion series coefficient (constant) comp: Compression space
Cf: Coefficient of fluctuations d, dis: Displacer
CLmin: Minimum clearance, m exp: Expansion Space
Cs: Starting coefficient max: Maximum
ddis: Diameter of displacer, m min: Minimum
ddisrod: Diameter of displacer rod, m p, pis: Piston
dpis: Diameter of the piston, m
e: Eccentricity in rhombic drive mechanism, m
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