Analisis rewetting time dan distribusi temperatur plat english rev04moh rohmatulloh
This document analyzes the effect of gap size on rewetting time and temperature distributions during the cooling process in a vertical rectangular narrow channel. The experiment used two vertical plates with an initial temperature of around 600°C. Cooling water with a flow rate of 0.09 L/s and saturated temperature was flowed through gaps of 1 mm, 2 mm, and 3 mm. The results showed that smaller gap sizes led to longer rewetting times, as smaller gaps increase vapor pressure and decrease the cooling water mass flow rate. Temperature distributions were similar initially for all gap sizes but decreased more slowly over time for smaller gaps.
A three-dimensional numerical analysis of laminar natural convection with entropy generation in an open trapezoidal cavity filled with water has been carried out. In this investigation, the inclined wall is maintained at isothermal hot temperature while cold water enters into the cavity from its right open boundary and all other walls are assumed to be perfect thermal insulators. Attention is paid on the effects of buoyancy forces on the flow structure and temperature distribution inside the open enclosure. Rayleigh number is the main parameter which changes from 103 to 105 and Prandtl number is fixed at Pr =6.2. Obtained results have been presented in the form of particles trajectories, iso-surfaces of temperature and those of entropy generated as well as the average Nusselt number. It has been found that the flow structure is sensitive to the value of Rayleigh number and that heat transfer increases with increasing this parameter.
Joule Heating in a Current Carrying Busbar FinalRobert Neal
1) The document describes simulations analyzing joule heating of an aluminum 6061-T6 busbar with different air flow conditions using COMSOL.
2) With no air flow, temperatures in the system exceeded 3000K, while cross flow of 2 ft/s air lowered the maximum temperature to around 330K. Parallel flow of 2 ft/s resulted in a maximum temperature of around 470K.
3) Future work includes simulating turbulent air flow inside and around the busbar, as well as evaluating the simulations with insulation on the busbar ends.
Effect of controlling parameters on heat transfer during spray impingement co...BIBHUTI BHUSAN SAMANTARAY
The heat transfer characteristics of air-water spray impingement cooling of stationary steel plate was experimentally investigated. Experiments were conducted on an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm. The controlling parameters taken during the experiments were air-water pressures, water flow rate, nozzle tip to target distance and mass impingement density. The effects of the controlling parameters on the cooling rates were critically examined during spray impingement cooling. Air assisted DM water was used as the quenchant media in the work. The cooling rates were calculated from the time dependent temperature profiles were recorded by NI-cRIO DAS at the desired locations of the bottom surface of the plate embedded with K-type thermocouples. By using MS-EXCEL the effects of these cooling rate parameters were analysed The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods in the present steel industries.
Experimental study of natural convection heat transfer in anAlexander Decker
This document summarizes an experimental study on the effects of mechanical vibration on natural convection heat transfer in an enclosed cubic cavity. Thermocouples measured temperature fields as the cavity was vibrated at different frequencies for two heat flux values. Vibration enhanced heat transfer more at low Rayleigh number, where vibration convection dominated over gravitational convection. Higher vibration frequencies accelerated the cavity reaching a steady temperature state. Results agreed with other studies on thermovibrational convection in cubic cells.
Isentropic Blow-Down Process and Discharge CoefficientSteven Cooke
The document describes an experiment to study the transient discharge of a pressurized tank through orifices of varying diameters, as well as a long tube, and compare the actual blowdown processes to an ideal isentropic process. An MKS pressure transducer and T-type thermocouple were calibrated. Pressure and temperature data were recorded during blowdown for each orifice/tube. The actual temperature decayed much more than the calculated isentropic temperature due to heat transfer. Discharge coefficients were calculated and ranged from 0.59 to 0.71, decreasing with smaller orifices/tubes due to friction.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
The document discusses various concepts related to thermal heat gain and loss in buildings, including:
- Thermal conductivity, resistivity, conductance, and resistance, which describe the ability of materials to allow heat to pass through them.
- Time lag and decrement factor, which characterize periodic heat flow patterns as outdoor temperatures fluctuate daily.
- Methods for calculating conduction, convection, radiation, and ventilation heat exchange in buildings.
- The concept of sol-air temperature, which combines radiant and convective heating effects on buildings.
- Factors like solar gain factor and surface conductance that influence a building's absorption of solar heat gain.
Analisis rewetting time dan distribusi temperatur plat english rev04moh rohmatulloh
This document analyzes the effect of gap size on rewetting time and temperature distributions during the cooling process in a vertical rectangular narrow channel. The experiment used two vertical plates with an initial temperature of around 600°C. Cooling water with a flow rate of 0.09 L/s and saturated temperature was flowed through gaps of 1 mm, 2 mm, and 3 mm. The results showed that smaller gap sizes led to longer rewetting times, as smaller gaps increase vapor pressure and decrease the cooling water mass flow rate. Temperature distributions were similar initially for all gap sizes but decreased more slowly over time for smaller gaps.
A three-dimensional numerical analysis of laminar natural convection with entropy generation in an open trapezoidal cavity filled with water has been carried out. In this investigation, the inclined wall is maintained at isothermal hot temperature while cold water enters into the cavity from its right open boundary and all other walls are assumed to be perfect thermal insulators. Attention is paid on the effects of buoyancy forces on the flow structure and temperature distribution inside the open enclosure. Rayleigh number is the main parameter which changes from 103 to 105 and Prandtl number is fixed at Pr =6.2. Obtained results have been presented in the form of particles trajectories, iso-surfaces of temperature and those of entropy generated as well as the average Nusselt number. It has been found that the flow structure is sensitive to the value of Rayleigh number and that heat transfer increases with increasing this parameter.
Joule Heating in a Current Carrying Busbar FinalRobert Neal
1) The document describes simulations analyzing joule heating of an aluminum 6061-T6 busbar with different air flow conditions using COMSOL.
2) With no air flow, temperatures in the system exceeded 3000K, while cross flow of 2 ft/s air lowered the maximum temperature to around 330K. Parallel flow of 2 ft/s resulted in a maximum temperature of around 470K.
3) Future work includes simulating turbulent air flow inside and around the busbar, as well as evaluating the simulations with insulation on the busbar ends.
Effect of controlling parameters on heat transfer during spray impingement co...BIBHUTI BHUSAN SAMANTARAY
The heat transfer characteristics of air-water spray impingement cooling of stationary steel plate was experimentally investigated. Experiments were conducted on an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm. The controlling parameters taken during the experiments were air-water pressures, water flow rate, nozzle tip to target distance and mass impingement density. The effects of the controlling parameters on the cooling rates were critically examined during spray impingement cooling. Air assisted DM water was used as the quenchant media in the work. The cooling rates were calculated from the time dependent temperature profiles were recorded by NI-cRIO DAS at the desired locations of the bottom surface of the plate embedded with K-type thermocouples. By using MS-EXCEL the effects of these cooling rate parameters were analysed The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods in the present steel industries.
Experimental study of natural convection heat transfer in anAlexander Decker
This document summarizes an experimental study on the effects of mechanical vibration on natural convection heat transfer in an enclosed cubic cavity. Thermocouples measured temperature fields as the cavity was vibrated at different frequencies for two heat flux values. Vibration enhanced heat transfer more at low Rayleigh number, where vibration convection dominated over gravitational convection. Higher vibration frequencies accelerated the cavity reaching a steady temperature state. Results agreed with other studies on thermovibrational convection in cubic cells.
Isentropic Blow-Down Process and Discharge CoefficientSteven Cooke
The document describes an experiment to study the transient discharge of a pressurized tank through orifices of varying diameters, as well as a long tube, and compare the actual blowdown processes to an ideal isentropic process. An MKS pressure transducer and T-type thermocouple were calibrated. Pressure and temperature data were recorded during blowdown for each orifice/tube. The actual temperature decayed much more than the calculated isentropic temperature due to heat transfer. Discharge coefficients were calculated and ranged from 0.59 to 0.71, decreasing with smaller orifices/tubes due to friction.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
The document discusses various concepts related to thermal heat gain and loss in buildings, including:
- Thermal conductivity, resistivity, conductance, and resistance, which describe the ability of materials to allow heat to pass through them.
- Time lag and decrement factor, which characterize periodic heat flow patterns as outdoor temperatures fluctuate daily.
- Methods for calculating conduction, convection, radiation, and ventilation heat exchange in buildings.
- The concept of sol-air temperature, which combines radiant and convective heating effects on buildings.
- Factors like solar gain factor and surface conductance that influence a building's absorption of solar heat gain.
The document discusses nucleate boiling heat transfer during flow boiling. It begins by describing the onset of nucleate boiling, which occurs when the wall temperature exceeds the local saturation temperature, allowing vapor bubbles to nucleate and grow. An energy balance relationship is presented to relate the temperature difference needed for nucleate boiling onset to the axial location along the tube. Various correlations for predicting the two-phase heat transfer coefficient during flow boiling are also presented, including the Chen correlation which accounts for both nucleate boiling and convective heat transfer contributions. The document concludes with a discussion of the Steiner-Taborek asymptotic model, which defines physical limits on the heat transfer coefficient during boiling.
This document discusses key concepts related to air conditioning and psychrometrics including:
1) Moist air is a mixture of dry air and water vapor, with the maximum quantity of water vapor an air parcel can hold dependent on temperature.
2) The dew point temperature is the temperature at which water molecules in the air start condensing.
3) Relative humidity is the ratio of the partial pressure of water vapor in an air-water vapor mixture to the saturated vapor pressure of water at a given temperature.
Refrigeration and air conditioning - psychrometry and air conditioning load e...NITIN AHER
This document provides an overview of psychrometrics and air conditioning load estimation. It defines key psychrometric concepts such as dry bulb temperature, relative humidity, humidity ratio, enthalpy, and introduces the psychrometric chart. It describes basic psychrometric processes including sensible heating and cooling, humidification, and dehumidification. It also discusses human comfort factors, the comfort chart, and an introduction to cooling load estimation.
The document discusses the principles of refrigeration and how it works. It begins by defining refrigeration as the process of removing heat from one substance and transferring it to another. It then explains the key concepts of heat, temperature, methods of heat transfer, latent heat, sensible heat, and the refrigeration cycle. Specifically:
- Refrigeration involves removing heat from one substance (the evaporator) and transferring it to another (the condenser) using a refrigerant that changes state from liquid to vapor and back.
- As the refrigerant absorbs heat in the evaporator, it changes from liquid to vapor. It then transfers the heat to the condenser, where it condenses back to liquid form after
This document discusses heat transfer in bioprocesses. It describes how heat is transferred between fluids through solid walls in equipment like heat exchangers to facilitate temperature regulation. Several common heat exchanger designs are examined, including double-pipe, shell-and-tube, and plate-fin heat exchangers. Heat transfer occurs primarily through conduction, with various flow arrangements and factors like surface area affecting the rate of transfer. Heat generation from microbial growth can be calculated based on substrate utilization and enthalpy balances are required to understand heat evolution in bioprocesses.
This document provides an overview of psychrometrics and psychrometric charts. It defines psychrometrics as the determination of physical and thermodynamic properties of gas-vapor mixtures. A psychrometric chart is a graphical representation of these properties at constant pressure, with two variables determining all other properties. The document outlines key psychrometric properties like dry bulb temperature, wet bulb temperature, dew point temperature, and relative humidity. It also describes common psychrometric processes and how to read a psychrometric chart. The conclusion emphasizes the importance of understanding psychrometrics for analyzing indoor conditions and designing optimal HVAC systems.
1) Boyle's law states that the pressure and volume of a gas are inversely proportional at constant temperature. Charles' law states that the volume of a gas is directly proportional to its temperature at constant pressure.
2) A refrigerant is a substance used in refrigeration to absorb heat from the space being refrigerated and release it elsewhere. Common refrigerants like Freon gas are used in refrigerators.
3) A refrigerator uses a vapor-compression cycle to cool its interior. Freon gas is compressed, condenses while releasing heat outside, then evaporates in the interior, absorbing heat and cooling the refrigerator. This cycle repeats continuously.
This document analyzes critical heat flux (CHF) in vertical rectangular narrow channels. It summarizes several previous studies that experimentally analyzed CHF in narrow channels using different fluids, channel dimensions, and heating conditions. The document then describes the author's own experiment on CHF using a vertical stainless steel plate with a 1 mm gap. Results showed the highest CHF occurred at the middle of the plate and CHF decreased towards the upper and lower parts. CHF values were compared to several existing correlations, with some correlations showing better agreement with results from different plate positions. The study contributes to understanding CHF in narrow channels.
This document discusses boiling and condensation processes. It defines boiling as the transition of a liquid to vapor when heated to the saturation temperature. There are different types of boiling including pool boiling, where fluid motion is from natural convection, and flow boiling, where an external pump forces liquid motion.
The boiling curve is presented, outlining the different boiling regimes of natural convection, nucleate boiling, transition boiling, and film boiling that occur as heat flux increases. Correlations are provided for calculating heat transfer in the nucleate and film boiling regimes.
Condensation occurs when vapor temperature decreases below saturation. It can be dropwise or film condensation, with dropwise having higher heat transfer. The rate of heat transfer
The document describes experiments conducted to calibrate flow rates, analyze heat transfer coefficients, and measure heat loss in a heat exchange system. Key findings include:
1) Calibration curves were developed to correlate pneumatic valve pressure to flow rates for different operation modes.
2) Heat transfer coefficients for process and cooling water were consistent with theoretical models based on Reynolds number.
3) Fouling was observed in the cooling water heat exchanger, indicated by higher heat transfer coefficients compared to the process water exchanger.
4) Total heat loss from the system was approximately 4 kW, representing around 10% of the total heat transferred from steam.
This document discusses psychrometric terms and relations. It defines dry air, moist air, saturated air, degree of saturation, humidity, absolute humidity, relative humidity, dry bulb temperature, wet bulb temperature, wet bulb depression, dew point temperature, dew point depression, and psychrometer. It describes Dalton's law of partial pressures and key psychrometric relations regarding specific humidity, degree of saturation, relative humidity, pressure of water vapor, and absolute humidity. An example problem is included to demonstrate calculating relative humidity, specific humidity, dew point temperature, enthalpy per kg of dry air, and volume of air mixture per kg of dry air given dry bulb temperature, wet bulb temperature, and barometric pressure.
Psychrometry: Properties and processes discusses key concepts in psychrometry including:
- Psychrometry is the study of properties of air-water vapor mixtures, commonly known as moist air. Moist air consists of dry air, water vapor, and other inert gases.
- Key psychrometric properties include specific humidity, relative humidity, dry bulb temperature, wet bulb temperature, dew point temperature, and degree of saturation.
- The sling psychrometer is used to measure wet bulb temperature by whirling two thermometers, one dry and one wet, through the air. Wet bulb depression indicates the specific humidity of air.
- Dew point temperature is the temperature at which air becomes saturated when cooled at constant
Thermodynamic Property Relations
Properties of pure substances
Maxwell Relations
P-v diagram of a pure substance
pvt surface diagram
How to read steam table using an example
The document discusses vapor-gas mixtures and air conditioning. It defines key temperature measurements including dry bulb temperature, wet bulb temperature, and dew point temperature. Wet bulb temperature is the temperature air would reach if cooled by evaporation until saturated. Dew point is the saturation temperature corresponding to vapor pressure. The document also examines adiabatic saturation temperature, which is the temperature of air at 100% relative humidity after passing through a long channel without heat transfer. It notes that adiabatic saturation temperature and wet bulb temperature are almost equal numerically for common applications.
The specific heat (C) is the quantity of heat required to raise the temperature of one gram of a substance by one degree Celsius or Kelvin. A calorimeter constant is a constant that measures the heat capacity of the calorimeter. It is calculated by applying a known amount of the heat and determining the resultant change in temperature in the calorimeter
This document provides an overview of psychrometry, which is the study of air and water vapor mixtures. It defines important psychrometric properties like dry bulb temperature, wet bulb temperature, humidity ratio, and enthalpy. It explains psychrometric processes like sensible heating, cooling, and humidification. The psychrometric chart is introduced as a tool to represent the thermodynamic properties of moist air. Common psychrometric devices like air washers are also discussed.
This document discusses psychrometrics and psychrometric processes. It defines key psychrometric concepts like dry bulb temperature, specific humidity, and psychrometric chart. It then explains various psychrometric processes like sensible cooling, heating, humidification, dehumidification, and combinations of these processes. These include the mixing of air streams using mass, moisture, and energy balances. Diagrams are provided to illustrate each process and how they affect dry bulb temperature and specific humidity on a psychrometric chart. An air washer is also described that can perform several psychrometric processes by varying the temperature of water sprayed into an air stream.
The Low-Temperature Radiant Floor Heating System Design and Experimental Stud...IJRES Journal
In order to analyze the temperature distribution of the low-temperature radiant floor heating system
that uses the condensing wall-hung boiler as the heat source, the heating system is designed according to a typical
house facing south in Shanghai. The experiments are carried out to study the effects of the supply water
temperature on the thermal comfort of the system. Eventually, the supply water temperature that makes people in
the room feel more comfortable is obtained. The result shows that in the condition of that the outside temperature
is 8~15℃ and the relative humidity is 30~70%RH, the temperature distribution in the room is from high to low
when the height is from bottom to top. The floor surface temperature is highest, but its uniformity is very poor.
When the heating system reaches the steady state, the air temperature of the room is uniform. When the supply
water temperature is 63℃ The room is relatively comfortable at the above experimental condition.
1. This document describes a laboratory experiment on thermal convection. The experiment uses a benchtop unit with an air duct, heating elements of different shapes, and sensors to study free and forced convection.
2. Calculations are shown to determine the heat transfer coefficient (h) for flat, pipe bundle, and fin-shaped heating elements. The h value is highest for the fin-shaped element and lowest for the flat element.
3. The conclusion states that different materials and heating element designs have varying heat transfer coefficients, which provides insight into how long it takes different objects to cool from the inside out.
The document discusses nucleate boiling heat transfer during flow boiling. It begins by describing the onset of nucleate boiling, which occurs when the wall temperature exceeds the local saturation temperature, allowing vapor bubbles to nucleate and grow. An energy balance relationship is presented to relate the temperature difference needed for nucleate boiling onset to the axial location along the tube. Various correlations for predicting the two-phase heat transfer coefficient during flow boiling are also presented, including the Chen correlation which accounts for both nucleate boiling and convective heat transfer contributions. The document concludes with a discussion of the Steiner-Taborek asymptotic model, which defines physical limits on the heat transfer coefficient during boiling.
This document discusses key concepts related to air conditioning and psychrometrics including:
1) Moist air is a mixture of dry air and water vapor, with the maximum quantity of water vapor an air parcel can hold dependent on temperature.
2) The dew point temperature is the temperature at which water molecules in the air start condensing.
3) Relative humidity is the ratio of the partial pressure of water vapor in an air-water vapor mixture to the saturated vapor pressure of water at a given temperature.
Refrigeration and air conditioning - psychrometry and air conditioning load e...NITIN AHER
This document provides an overview of psychrometrics and air conditioning load estimation. It defines key psychrometric concepts such as dry bulb temperature, relative humidity, humidity ratio, enthalpy, and introduces the psychrometric chart. It describes basic psychrometric processes including sensible heating and cooling, humidification, and dehumidification. It also discusses human comfort factors, the comfort chart, and an introduction to cooling load estimation.
The document discusses the principles of refrigeration and how it works. It begins by defining refrigeration as the process of removing heat from one substance and transferring it to another. It then explains the key concepts of heat, temperature, methods of heat transfer, latent heat, sensible heat, and the refrigeration cycle. Specifically:
- Refrigeration involves removing heat from one substance (the evaporator) and transferring it to another (the condenser) using a refrigerant that changes state from liquid to vapor and back.
- As the refrigerant absorbs heat in the evaporator, it changes from liquid to vapor. It then transfers the heat to the condenser, where it condenses back to liquid form after
This document discusses heat transfer in bioprocesses. It describes how heat is transferred between fluids through solid walls in equipment like heat exchangers to facilitate temperature regulation. Several common heat exchanger designs are examined, including double-pipe, shell-and-tube, and plate-fin heat exchangers. Heat transfer occurs primarily through conduction, with various flow arrangements and factors like surface area affecting the rate of transfer. Heat generation from microbial growth can be calculated based on substrate utilization and enthalpy balances are required to understand heat evolution in bioprocesses.
This document provides an overview of psychrometrics and psychrometric charts. It defines psychrometrics as the determination of physical and thermodynamic properties of gas-vapor mixtures. A psychrometric chart is a graphical representation of these properties at constant pressure, with two variables determining all other properties. The document outlines key psychrometric properties like dry bulb temperature, wet bulb temperature, dew point temperature, and relative humidity. It also describes common psychrometric processes and how to read a psychrometric chart. The conclusion emphasizes the importance of understanding psychrometrics for analyzing indoor conditions and designing optimal HVAC systems.
1) Boyle's law states that the pressure and volume of a gas are inversely proportional at constant temperature. Charles' law states that the volume of a gas is directly proportional to its temperature at constant pressure.
2) A refrigerant is a substance used in refrigeration to absorb heat from the space being refrigerated and release it elsewhere. Common refrigerants like Freon gas are used in refrigerators.
3) A refrigerator uses a vapor-compression cycle to cool its interior. Freon gas is compressed, condenses while releasing heat outside, then evaporates in the interior, absorbing heat and cooling the refrigerator. This cycle repeats continuously.
This document analyzes critical heat flux (CHF) in vertical rectangular narrow channels. It summarizes several previous studies that experimentally analyzed CHF in narrow channels using different fluids, channel dimensions, and heating conditions. The document then describes the author's own experiment on CHF using a vertical stainless steel plate with a 1 mm gap. Results showed the highest CHF occurred at the middle of the plate and CHF decreased towards the upper and lower parts. CHF values were compared to several existing correlations, with some correlations showing better agreement with results from different plate positions. The study contributes to understanding CHF in narrow channels.
This document discusses boiling and condensation processes. It defines boiling as the transition of a liquid to vapor when heated to the saturation temperature. There are different types of boiling including pool boiling, where fluid motion is from natural convection, and flow boiling, where an external pump forces liquid motion.
The boiling curve is presented, outlining the different boiling regimes of natural convection, nucleate boiling, transition boiling, and film boiling that occur as heat flux increases. Correlations are provided for calculating heat transfer in the nucleate and film boiling regimes.
Condensation occurs when vapor temperature decreases below saturation. It can be dropwise or film condensation, with dropwise having higher heat transfer. The rate of heat transfer
The document describes experiments conducted to calibrate flow rates, analyze heat transfer coefficients, and measure heat loss in a heat exchange system. Key findings include:
1) Calibration curves were developed to correlate pneumatic valve pressure to flow rates for different operation modes.
2) Heat transfer coefficients for process and cooling water were consistent with theoretical models based on Reynolds number.
3) Fouling was observed in the cooling water heat exchanger, indicated by higher heat transfer coefficients compared to the process water exchanger.
4) Total heat loss from the system was approximately 4 kW, representing around 10% of the total heat transferred from steam.
This document discusses psychrometric terms and relations. It defines dry air, moist air, saturated air, degree of saturation, humidity, absolute humidity, relative humidity, dry bulb temperature, wet bulb temperature, wet bulb depression, dew point temperature, dew point depression, and psychrometer. It describes Dalton's law of partial pressures and key psychrometric relations regarding specific humidity, degree of saturation, relative humidity, pressure of water vapor, and absolute humidity. An example problem is included to demonstrate calculating relative humidity, specific humidity, dew point temperature, enthalpy per kg of dry air, and volume of air mixture per kg of dry air given dry bulb temperature, wet bulb temperature, and barometric pressure.
Psychrometry: Properties and processes discusses key concepts in psychrometry including:
- Psychrometry is the study of properties of air-water vapor mixtures, commonly known as moist air. Moist air consists of dry air, water vapor, and other inert gases.
- Key psychrometric properties include specific humidity, relative humidity, dry bulb temperature, wet bulb temperature, dew point temperature, and degree of saturation.
- The sling psychrometer is used to measure wet bulb temperature by whirling two thermometers, one dry and one wet, through the air. Wet bulb depression indicates the specific humidity of air.
- Dew point temperature is the temperature at which air becomes saturated when cooled at constant
Thermodynamic Property Relations
Properties of pure substances
Maxwell Relations
P-v diagram of a pure substance
pvt surface diagram
How to read steam table using an example
The document discusses vapor-gas mixtures and air conditioning. It defines key temperature measurements including dry bulb temperature, wet bulb temperature, and dew point temperature. Wet bulb temperature is the temperature air would reach if cooled by evaporation until saturated. Dew point is the saturation temperature corresponding to vapor pressure. The document also examines adiabatic saturation temperature, which is the temperature of air at 100% relative humidity after passing through a long channel without heat transfer. It notes that adiabatic saturation temperature and wet bulb temperature are almost equal numerically for common applications.
The specific heat (C) is the quantity of heat required to raise the temperature of one gram of a substance by one degree Celsius or Kelvin. A calorimeter constant is a constant that measures the heat capacity of the calorimeter. It is calculated by applying a known amount of the heat and determining the resultant change in temperature in the calorimeter
This document provides an overview of psychrometry, which is the study of air and water vapor mixtures. It defines important psychrometric properties like dry bulb temperature, wet bulb temperature, humidity ratio, and enthalpy. It explains psychrometric processes like sensible heating, cooling, and humidification. The psychrometric chart is introduced as a tool to represent the thermodynamic properties of moist air. Common psychrometric devices like air washers are also discussed.
This document discusses psychrometrics and psychrometric processes. It defines key psychrometric concepts like dry bulb temperature, specific humidity, and psychrometric chart. It then explains various psychrometric processes like sensible cooling, heating, humidification, dehumidification, and combinations of these processes. These include the mixing of air streams using mass, moisture, and energy balances. Diagrams are provided to illustrate each process and how they affect dry bulb temperature and specific humidity on a psychrometric chart. An air washer is also described that can perform several psychrometric processes by varying the temperature of water sprayed into an air stream.
The Low-Temperature Radiant Floor Heating System Design and Experimental Stud...IJRES Journal
In order to analyze the temperature distribution of the low-temperature radiant floor heating system
that uses the condensing wall-hung boiler as the heat source, the heating system is designed according to a typical
house facing south in Shanghai. The experiments are carried out to study the effects of the supply water
temperature on the thermal comfort of the system. Eventually, the supply water temperature that makes people in
the room feel more comfortable is obtained. The result shows that in the condition of that the outside temperature
is 8~15℃ and the relative humidity is 30~70%RH, the temperature distribution in the room is from high to low
when the height is from bottom to top. The floor surface temperature is highest, but its uniformity is very poor.
When the heating system reaches the steady state, the air temperature of the room is uniform. When the supply
water temperature is 63℃ The room is relatively comfortable at the above experimental condition.
1. This document describes a laboratory experiment on thermal convection. The experiment uses a benchtop unit with an air duct, heating elements of different shapes, and sensors to study free and forced convection.
2. Calculations are shown to determine the heat transfer coefficient (h) for flat, pipe bundle, and fin-shaped heating elements. The h value is highest for the fin-shaped element and lowest for the flat element.
3. The conclusion states that different materials and heating element designs have varying heat transfer coefficients, which provides insight into how long it takes different objects to cool from the inside out.
FINAL_201 Thursday A-3 Convective and Radiant Heat TransferKaylene Kowalski
This document describes an experiment on heat transfer through various modes. Thermocouples measured the temperature of a heated cylinder surface and surrounding air temperature. The experiment determined heat loss coefficients and amounts due to radiation, natural convection, and forced convection by varying voltage, temperature, and air velocity. Total heat loss was calculated from individual heat losses to understand heat transfer under different conditions.
This document summarizes a numerical study of heat transfer characteristics inside a bottom-heated square enclosure. Simulations were conducted for air and Al2O3-water nanofluid inside the enclosure as the conducting medium. Results showed that heat transfer rate, as measured by Nusselt number, increased with increasing hot wall temperature. For air, heat transfer occurred through bulk fluid motion, while for nanofluid it occurred through local interactions. However, nanofluids also exhibited bulk motion at higher temperatures. Isotherm and streamline patterns revealed higher heat transfer and more organized flow for nanofluids compared to air.
Study on Natural Convection in a Square Cavity with Wavy right vertical wall ...IOSRJMCE
In the present study, natural convection problem has been solved in a cavity having three flat walls and the right vertical wall consisting of one undulation and three undulations. The two vertical and bottom walls are cold walls maintained at a fixed temperature whereas the top wall is heated with spatially varying temperature distribution. Air has been taken as the working fluid with Pr =0.71. This problem is solved by SIMPLE algorithm with deferred QUICK scheme in curvilinear co-ordinates. A wide range of Rayleigh number (103 to 106 ) has been chosen for this study. For small Ra, the heat transfer was dominated by conduction across the fluid layers. With increase of Ra, the process began to be dominated by convection. In the presence of undulation the peak point of the heat rejection (negative local Nusselt number) in the right wall increases by 5.54% than left wall for Ra = 104 . The three undulations case had maximum heat transfer to the uppermost undulation compared to that of the one undulation case
Introduction
Mechanism of Heat Flow
Conduction
Heat Flow through a Cylinder-Conduction
Conduction through fluids
Convection
Film type condensation
Cold liquid-boiling of liquids
Modes of Feed-Heat Transfer
Thermal Radiation
Black Body
Grey body
Equipments
References
2.1 Heat
Heat is a form of energy. According to the principle of thermodynamics whenever a physical or chemical transformation occurs heat flow into or leaves the system.
A number of sources of heat are used for industrial scale operations steam and electric power is the chief sources to transfer heat. It is essential to cover steam without any loses to the apparatus in which it is used. The study of heat transfer processes helps in be signing the plant efficiently and economically
2.2 Heat Transfer:-
Work is one of the basic modes of energy transfer in machines the action of force on a moving body is identified as work. The work is done by a force as it acts upon a body moving in the direction of the force.
Work transfer is considered as occurring between the system and the surroundings work is said to be done by a system is the sole effect on things external to the system can be reduced to the raising of a weight.
If a system has a non-adiabatic boundary its temperature is not independent of the temperature of the surroundings and for the system between the states 1 and 2 the work w depends on path and the differential d-w is inexact. The work depends on the terminal state 1 and 2 as well as non-adiabatic path connecting them. For consistency with the principle of conservation of energy. Some type of energy transfer must have occurred because of the temperature difference between the system and its surroundings and it is identified as heat thus when an effect in a system occurs solely as result of temperature difference between the system and some other system the process in which the effect occur shall be called a transfer of heat from the system at the higher temperature to the system at the lower temperature.
1.1 Evaporation
1.2 Distillation
1.3 Drying
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A Study on the Performance of Cooling Ceiling Panel
1. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-20052
A Study on the Performance of
Cooling Ceiling Panel
Dr. Chirdpun Vitooraporn1
and Aryut Wattanawanichakorn2
1
Lecturer at Building Technology and Environment Laboratory,
2
Former graduate student
Mechanical Engineering Department, Chulalongkorn University,
Phyathai Rd, Patumwan, Bangkok, Thailand, 10330
Tel: 662-2218-6622 Fax: 662-2252-2889 E-mail: chirdpun@chula.com1
In this research the performance of cooling ceiling panel in transferring heat is studied. The
parameters considered in the experiment are supplied chilled water temperature, supplied chilled water
flow rate, and the cooling performance of the panel. From the experiment, it is found that supplied chilled
water temperature has an effect on the surface temperature of the panel, the room temperature and the
heat transfer rate of the panel at the steady state condition. Low supplied chilled water temperature
increases the heat transfer rate of the panel, and, at the same time, decreases the surface temperature
of the panel as well as the room temperature. In the contrary, the supplied chilled water flow rate does
not significantly affect the surface temperature of the panel, the room temperature, and the heat transfer
rate of the panel at the steady state condition. However, the supplied chilled water flow rate has an effect
on the time gradient required for the surface temperature of the panel, the room temperature and the
heat transfer rate of the panel to approach the steady state condition. The surface temperature of the
panel, the room temperature and the heat transfer rate of the panel approach the steady state
condition faster as the supplied chilled water flow rate increases. Furthermore, heat load also plays an
important effect on the surface temperature of the panel and the room temperature at the steady state
condition. Higher heat load results in higher surface temperature of the panel and room
temperature at the steady state condition. Results from experiment are used to derive the equations that
represent the cooling performance of the panel at the steady state condition.
Abstract
2. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-2005 3
1. Introduction
The cooling ceiling panel transfers heat to
or from a room by convection and radiation. The
radiant loads from the wall as well as from the
persons and objects within the room are treated
directly. The natural convection occurs at the air
layer near the cooling ceiling panel. This heated air
then moves and mixes with the air inside the room
under the buoyancy force. This mechanism hap-
pens because of the low panel temperature. The
panel is the metal ceiling panel bonded to the cop-
per tube. The tube contains the re-circulated
cooling media which is water. The combined
radiant and convection heat transfer is then trans-
ferred to the panel through the conduction heat
transfer happened at the tubes. Water inside the
tube is then gradually heated up and circulated back
to the chiller where all the heat contained is
dissipated.
2.1 Radiation Heat Transfer
The radiation heat transfer rate for the
cooling ceiling panel is calculated using the
equation from Walton (1980). The mean radiant
temperature (MRT) method is used to calculate the
radiation heat transfer in the multi-surface
enclosure. This multi-surface enclosure is reduced
to a two-surface approximation. For radiant
interchange in a room, one surface is occupied by
the cooling ceiling panel where the average
surface temperature is tp
. The other surface is oc-
cupied by other multi-surface enclosure. This sur-
face is assumed to be a fictitious surface that has
an area emissivity and temperature giving, tr
, about
the same heat transfer from the surface as the real
multi-surfaceenclosure.TheMRTequationisshown
in equation (1)
(1)
where
Fr
= Radiation interchange factor (dimensionless)
= Stefan-Boltzman constant = 5.669x10-8
(W/m2
-K4
)
qr
= Net radiation heat transferred by cooling
ceiling panel (W/m2
)
The fictitious surface temperature, tr
, is
calculated by using the weighted average
temperature and the emissivity of all un-cooled
surfaces. When the emissivities of un-cooled
surfaces are closely equal then the fictitious
surface temperature, tr
, can be approximated from
the weighted surface temperature of all un-cooled
surfaces.
2. Related Theory
The cooling loads considered for the
cooling ceiling panel in this research are radiation
load from floors and walls, natural convection load,
and heat load from lighting fixtures.
Figure 1 Heat transfer mechanism of the cooling ceiling panel
radiation
convection
heat transfer profile
heat source
cooling water
pipe
cooling
element
3. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-20054
In practice, the emissivity of nonmetallic or
painted metal nonreflecting surfaces is about 0.9.
When this emissivity is used, the radiation
interchange factor is about 0.87 for most rooms.
Therefore equation (1) can be rewritten as follow;
(2)
where
tp
= Surface temperature of the cooling
ceiling panel (o
C)
AUST = Area-weighted average temperature of
un-cooled surfaces in room (o
C)
2.2 Natural Convection Heat Transfer
The convection heat transfer in the
cooling ceiling panel system is normally natural. The
air motion is generated by the cooling of the
boundary layer of air near the panel. However, in
practice, many factors such as, infiltration or the
movement of persons may interfere and affect
natural convection or even induces forced
convection.
The convection heat transfer for the
cooling ceiling panel is calculated by using the
equationfromSchutrumandVouris(1954).Schutrum
and Vouris also showed that the room size
normally has no significant effect to the rate of
natural convection heat transfer except for the
very large size of room. Therefore the natural
convection heat transfer rate for the panel is
calculated as follow;
(3)
where
qc
= Heat transfer by natural convection (W/m2
)
tp
= Surface temperature of the panel (o
C)
ta
= Air temperature (o
C)
2.3 Radiation Heat Transfer from
Lighting Fixtures
The heat load inside the set up room in
this research comes from the 40 W light fixture.
The number of light fixture used are varied
depended on each case study. This heat load can
be calculated from
(4)
where
qb
= Radiation heat transfer from light fixture to
panel (W/m2
)
tb
= Surface temperature of light fixture (K)
tp
= Surface temperature of the panel (K)
Ab-p
= Surface area of light fixture (m2
)
nb
= No. of light fixture per unit area (set/m2
)
b
= Emissivity of light fixture surface
= Stefan-Boltzman constant = 5.669x10-8
W/(m2
-K4
)
3. Experimental Set Up
The set up room is 1x2 m. with 1 m. in
height. Eight ceiling cooling panels with size
50x50 cm. are installed inside the room. Closed
cell insulation is used to cover the top of the panel.
Details of the panel is shown in fig. 2. Figure 3
shows the chilled water circuit used in the
experiment. The supplied chilled water
4. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-2005 5
Figure 2 Details of cooling ceiling panel
Figure 3 Chilled water circuit
temperature, supplied chilled water flow rate, and
heat load inside the room are varied in order to
study the effect of these parameters to the cooling
performance of the panel. Five case studies are set
up where the supplied chilled water temperature
to the panel is 6.3, 8.5, 11.1, 14.4, and 16.3 o
C.
Seven additional sub-case studies for each constant
supplied chilled water temperature are also set up
as shown in table 1. Therefore the no. of
experiment is in total of thirty five case studies.
Table 1 7 sub case studies for each constant
supplied chill water temperature
In each experiment, the following
parameters are measured at various time until they
reach the steady state condition, ie. surface
temperature of the panel, floor and internal wall
temperature, supplied and return chilled water
temperature to the panel, and room temperature.
No. Flow rate Internal heat load
1 0.5 liter/min. -
2 1.0 liter/min. -
3 1.5 liter/min. -
4 1.5 liter/min. 1 set of 40 watt light fixture
5 1.5 liter/min. 2 sets of 40 watt light fixture
6 1.5 liter/min. 3 sets of 40 watt light fixture
7 1.5 liter/min. 4 sets of 40 watt light fixture
5. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-20056
4. Data Analysis
4.1 Chilled Water Temperature Effect to
the Cooling Performance of the Panel
Results from the experiment in all cases
show that the panel surface temperature decreases
rapidly at the beginning. After that the rate is slow
down and the temperature becomes constant. It is
also found that lower supplied chilled water
temperature results in lower panel surface
temperature provided that the internal heat load is
unchanged. The supplied chilled water temperature
also affects the rate of change of panel surface
temperature at the beginning, ie. at low supplied
chilled water temperature, the panel surface
temperature changes faster than that at high
supplied chilled water temperature as shown in
fig. 4.
The effect of supplied chilled water
temperature to room temperature is shown in fig.
5. With the same heat load, low supplied chilled
water provides lower room temperature at steady
state condition than that at high supplied chilled
water temperature. The supplied chilled water
temperature also has an effect to the rate of change
of room temperature, ie: with low supplied chilled
water temperature, the room temperature changes
faster than that at high supplied chilled water
temperature.
Figure 4 Comparison of mean panel surface temperature for
various chilled water temperature at 1.5 liter/min.
with 2 light fixtures at 40 W. each
Figure 5 Comparison of room temperature for various
supplied chilled water temperature at 1.5 liter/min.
with 2 light fixtures at 40 W. each
Figure 6 Comparison of heat transfer amount of the cooling
ceiling panel and room temperature at steady state
condition for supplied chilled water temperature 6.3,
8.5, 11.1,14.4, and 16.3 o
C at 1.5 liter/min and
2 light fixtures with 40 W each.
6. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-2005 7
The effect of supplied chilled water
temperature to the rate of heat transfer of the panel
is shown in fig. 6. With the same heat load, low
supplied chilled water temperature provides higher
rate of heat transfer of the panel than that at high
supplied chilled water temperature. This is because
the panel surface temperature at steady state
condition is lower at low supplied chilled water
temperature as mentioned earlier. The cooling
performance of the panel increases as the panel
surface temperature decreases. Since the cooling
performance of the panel increases when supplied
chilled water temperature is low, then the panel
can maintain lower room temperature than that
in the case of high supplied chilled water
temperature for the same internal heat load.
4.2 Effect of Chilled Water Flow Rate
to the Cooling Performance of the Panel
Supplied chilled water flow rate has an
important effect to the time required for the panel
surface temperature to approach the steady state
condition. With constant supplied chilled water
temperature, the panel surface temperature
approaches the steady state condition faster at high
supplied chilled water flow rate than that at low
supplied chilled water flow rate. However, supplied
chilled water flow rate plays no effect to the panel
surface temperature at steady state condition as
shown in fig. 7. Similar effect also occurs for the
room temperature as shown in fig. 8.
Fig.9. shows the effect of supplied chilled
water flow rate to the heat transfer rate of the
panel. There is no vivid effect of supplied chilled
water flow rate to the amount of heat transfer of
the panel at steady state condition since the
supplied chilled water flow rate has no effect to
the panel surface temperature at steady state
condition as mentioned earlier.
Figure 7 Comparison of mean panel surface temperature when
supplied chilled water temperature is 8.5 o
C at 0.5,
1, and 1.5 liter/min with no internal heat load
Figure 8 Comparison of room temperature when supplied
chilled water temperature is 8.5 o
C at 0.5, 1, 1.5
liter/min with no internal heat load
7. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-20058
Theinternalheatloadalsoaffectstheroom
temperature at steady state condition as shown in
fig.11.Theroomtemperatureapproachesthesteady
state condition at higher temperature for high
internal heat load. The amount of internal
heat load also affects the rate of change of
room temperature at the beginning. The room
temperature changes slower when high amount of
internal heat load is applied.
Figure 10 Comparison of room temperature for 0, 1, 2, 3,
and 4 light fixtures at 40 W. each at 8.5 o
C and
1.5 liter/min. of supplied chilled water flow rate
4.3 Effect of Internal Heat Load to the
Cooling Performance of the Panel
The amount of internal heat load has an
effect to the panel surface temperature at steady
state condition. The panel surface temperature is
higher at high amount of internal heat load while
the rate of change of panel surface temperature is
slower at high internal heat load as shown in
fig. 10
Figure 9 Comparison of heat transfer amount of the panel
and room temperature at steady state condition
when supplied chilled water flow rate is 0.5, 1, 1.5
liter/min at 11.1 o
C with no internal heat load
Figure 10 Comparison of mean panel surface temperature with
0, 1, 2, 3, and 4 light fixtures at 40 W. each for
8.5 o
C and 1.5 liter/min. supplied chilled water flow
rate 5. Derivation of Equations
Data received from the experiment are used
to develop the equations for the panel. The
equations developed are proposed to use as a
guideline to design the cooling ceiling panel.
5.1 EquationforCalculatingtheSurface
Temperature of the Panel
Since conduction heat transfer occurs
between the surface of the panel and chilled water
8. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-2005 9
inside the tube, therefore the main parameter is
the total thermal resistance of the panel (Ru
). It is
the result from the thermal resistance of the tube
wall (rt
), the thermal resistance between the chilled
water tube and the panel (rp
)
Consider the total thermal resistance of the
panel per unit area
(5)
where
Ru
= Total thermal resistance of the panel(m2
-K/W)
rt
= Thermal resistance of the tube wall per unit
distance between the tube (m-K/W)
rs
= Thermal resistance between the tube and
panel per unit distance between the tube
(m-K/W)
rp
= Thermal resistance of the panel (m2
-K/W)
M = Distance between the tubes measured from
center of the tube (m)
rt
and rp
of the panel can be calculated using the
following equations;
(6)
(7)
where
Do
, Di
= Inside and outside diameter of the tube
(m)
kp
= Thermal conductivity of the panel
(W/m-K)
xp
= Thickness of the panel (m)
For the thermal resistance between the tube
and panel per unit distance between the tubes,
ASHRAE (1992) indicates that the thermal
resistance depends on the installed configuration
of the tube to the panel which has no relation to
the tube diameter. Therefore this thermal resistance
can be calculated by developing the relationship
between the difference of panel surface
temperature and mean chilled water temperature,
ie. tm
shown in equation 8, and the amount of
heat transfer through the panel at steady state
condition (qt
) . The result is shown in equation 9
(8)
where
tp
= Mean surface temperature of the panel (o
C)
twi
= Inlet chilled water temperature (o
C)
two
= Outlet chilled water temperature (o
C)
or
(9)
where k is the constant value determined
from the regression analysis and equal to 47.46943
W/m2
-o
C. This k value is in fact the total heat
transfer coefficient of the panel (U) or
(10)
where U is equal to 0.02107 m2
-o
C/W
The total thermal resistance is then used,
along with the rt
and rp
, to calculate the thermal
resistance between the tube and the panel
according to equation 5. Its value is 0.2106 m2
-o
C/W.
Equation 5 is then rearranged along with
tm
from equation 8, rt
and rp
from equation 6
and 7 such that the surface temperature of the
panel is in the left hand side of the equation. The
new arranged equation, equation 11, can be used
to predict the surface temperature of the panel at
steady state condition when the dimension related
9. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-200510
where
qt
= Heat flux of the panel at steady state
condition (W/m2
)
tr
= Room temperature at steady state
condition (o
C)
tp
= Mean surface temperature of the panel at
steady state condition (o
C)
A,B= Constants to be found from the
experimental results
The coefficient A and B found from the
experimental results are equal to 7.9194 and 1.1675
respectively. Therefore equation (12) is then
(13)
Substitute tp
from equation 11 into equation 13
The equation above can be used to
calculate the cooling performance of the panel when
knowing the configuration of the tube inside the
panel.
to the panel and the chilled water temperature are
known.
where
tp
= Mean surface temperature of the panel at
steady state condition (o
C)
qt
= Heat flux of the panel at steady state
condition (W/m2
)
tw_avg
=Mean chilled water temperature =
0.5 (twi + two) (o
C)
M =Distancebetweenthetubemeasuredfrom
center of the tube (m)
Do
=Outside diameter of the tube (m)
Di
=Inside diameter of the tube (m)
kt
=Thermal conductivity of the tube (W/m-K)
xp
=Thickness of the panel (m)
kp
=Thermal conductivity of the panel
(W/m-K)
The equation above is then used to develop
the equation for calculating the cooling performance
of the panel.
5.2 Equation for Calculating the
Cooling Performance of the Panel at Steady
State Condition
Results from the experiment are used to
find the relation among the cooling performance of
the panel, the surface temperature of the panel,
and room temperature at steady state condition.
The relation found is shown in equation below
(12)
(11)
(14)
10. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-2005 11
6. Conclusion
Result from the experiment can be concluded as follow;
4. Total rate of heat transfer of the panel
depends on the level of supplied chilled water
temperature. Low supplied chilled water
temperature results in higher rate of heat transfer
of the panel. In the contrary, supplied chilled water
flow rate has no vivid effect to the rate of heat
transfer of the panel at steady state condition.
1. Supplied chilled water temperature has
an effect to the surface temperature of the panel
and room temperature at steady state condition.
Low supplied chilled water temperature results in
lower surface temperature of the panel and room
temperature at the same internal heat load.
2. Supplied chilled water flow rate has no
vivid effect to the level of surface temperature of
the panel and room temperature at steady state
condition. However it affects the time for the panel
surface temperature and room temperature to
approach the steady state condition. High supplied
chilled water flow rate to the panel results in faster
approaching time for the surface temperature of
the panel and room temperature to reach the steady
state condition.
3. The amount of internal heat load has
an effect to the level of surface temperature of the
panel and room temperature at steady state
condition. Higher internal heat load results in higher
surface temperature of the panel and room
temperature at steady state condition.
11. A S H R A E T h a i l a n d C h a p t e r
ASHRAE Journal 2004-200512
References
[1] ASHRAE, 1992, ASHRAE Systems and Equipment Handbooks (SI) 1992. Atlanta:
American Society of Heating, Refrigeration and Air-Conditioning Engineers, Inc.
[2] Incropera, F.P., and Dewitt, D.P., 1996, Fundamentals of Heat and Mass Transfer.
4th
ed. New York : John Wiley & Sons.
[3] Walton, G.N., 1980, A new algorithm for radian interchange in room loads calculations.
ASHRAE Transactions 86, p.190-208.
[4] Schutrum, L.F. and J.D. Vouris, 1954, Effects of room size and non-uniformity of panel
temperature on panel performance. ASHRAE Transaction 60, p.455.
[5] Aryut Wattanawanichakorn, 2003, A study of the performance of cooling ceiling panel,
ME thesis, Department of Mechanical Engineering, Chulalongkorn University.