This is for energy conservation and management , More information about energy efficiency in thermal utilities & systems.

1. BVM ENGINEERING COLLEGE
ENERGY CONSERVATION & MANAGEMENT [3ME84]
GUIDED BY: HITESH A. BHARGAV.

2. INTRODUCTION
 NAME: SAMAR SATTARBHAI MANSURI
 ID NUMBER: 20CE151
 BATCH : C07K
 BRANCH: CIVIL
 SUBJECT: ENERGY CONSERVATION & MANAGEMENT [3ME84]
 TOPIC NAME: ENERGY EFFICIENCY IN THERMAL UTILITIES & SYSTEMS

3. ENERGY EFFICIENCY
 It can be termed as the ratio of useful energy output to the total energy input.
 It’s denoted by Ƞ.
 Equipments are said to be efficient if they are utiliting maximum amount of input energy.

4. ENERGY PERFORMANCE ASSESSMENT OF BOILER
Purpose of performance test
 To find out efficiency of boiler
 To find out evaporation ratio
The purpose of performance test is to determine actual
performance and efficiency of boiler and compare it with
design values and norms.

5. 1. Boiler efficiency, Ƞ=
𝐻𝑒𝑎𝑡 𝑜𝑢𝑡𝑝𝑢𝑡
𝐻𝑒𝑎𝑡 𝑖𝑛𝑝𝑢𝑡
×100
Ƞ=
𝐻𝑒𝑎𝑡 𝑜𝑢𝑡𝑝𝑢𝑡 𝑖𝑛 𝑓𝑜𝑟𝑚 𝑜𝑓 𝑠𝑡𝑒𝑎𝑚 (𝑘𝐶𝑎𝑙𝑠)
𝐻𝑒𝑎𝑡 𝑖𝑛𝑝𝑢𝑡 𝑖𝑛 𝑓𝑜𝑟𝑚 𝑜𝑓 𝑓𝑢𝑒𝑙 (/𝑘𝐶𝑎𝑙𝑠)
×100
2. Evaporation ratio =
𝑄𝑢𝑎𝑛𝑡𝑖𝑡𝑦 𝑜𝑓 ℎ𝑒𝑎𝑡 𝑔𝑒𝑛𝑒𝑟𝑎𝑡𝑒𝑑
𝑄𝑢𝑎𝑛𝑡𝑖𝑡𝑦 𝑜𝑓 𝑓𝑢𝑒𝑙 𝑐𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛

6. BOILER EFFICIENCY CAN BE TESTED BY FOLLOWING METHOD:
1. Direct Method: Where the energy gain of working fluid (water and steam) is compared with energy
content of boiler fuel.
2. Indirect Method: Where the efficiency is the difference between losses and energy input.

7. DIRECT METHOD
 It is also known as “Input-Output Method” due to fact that it needs only the useful output (steam) and
the heat input (i.e. fuel) for evaluating the efficiency.
Boiler Efficiency=
𝐻𝑒𝑎𝑡 𝑂𝑢𝑡𝑝𝑢𝑡
𝐻𝑒𝑎𝑡 𝐼𝑛𝑝𝑢𝑡

8.  Efficiency =
𝐻𝑒𝑎𝑡 𝑎𝑑𝑑𝑖𝑡𝑖𝑜𝑛 𝑡𝑜 𝑆𝑡𝑒𝑎𝑚
𝐺𝑟𝑜𝑠𝑠 𝐻𝑒𝑎𝑡 𝑖𝑛 𝐹𝑢𝑒𝑙
× 100
 Boiler Efficiency=
𝑆𝑡𝑒𝑎𝑚 𝑓𝑙𝑜𝑤 ×(𝑠𝑡𝑒𝑎𝑚 𝑒𝑛𝑡ℎ𝑎𝑙𝑝𝑦 −𝑓𝑒𝑒𝑑 𝑤𝑎𝑡𝑒𝑟 𝑒𝑛𝑡ℎ𝑎𝑙𝑝𝑦)
𝐹𝑢𝑒𝑙 𝑓𝑖𝑟𝑖𝑛𝑔 𝑟𝑎𝑡𝑒 × 𝑔𝑟𝑜𝑠𝑠 𝑐𝑎𝑙𝑜𝑟𝑖𝑓𝑖𝑐 𝑣𝑎𝑙𝑢𝑒
100

9.  Boiler efficiency =
𝑄 × 𝐻−ℎ ×100
(𝑞 ×𝐺𝐶𝑉)
Where, Q =Quantity of steam generated per hour (kg/hr)
q =Quantity of fuel used per hour (kg/hr)
GCV=Gross calorific value of the fuel (kCal/kg)
H =Enthalpy of steam (kCal/kg)
h =Enthalpy of feed water (kCal/kg)

10. MERITS & DEMERITS OF DIRECT METHOD:
 Merits:
 Plant people can evaluate quickly the efficiency of boilers
 Requires few parameters for computation
 Needs few instruments for monitoring
 Demerits:
 Does not give clues to operate as to why efficiency of system is lower
 Does not calculate various losses accountable for various efficiency levels

11. INDIRECT METHOD
 The disadvantages of the direct method can be overcome by this method, which calculates the various
heat losses associated with boiler.
 An important advantage of this method is that the error in measurement do not make significant change
in efficiency.
 In indirect method, 1% error in measurement of losses will result in Efficiency = 100 – (10 ±0.1)
90 ± 0.1 = 89.9 𝑡𝑜 90.1

13. LOSSES APPLICABLE TO LIQUID, GAS & SOLID FIRED BOILER
L1. Loss due to dry flue gas (sensible heat)
L2. Loss due to hydrogen in fuel (H2)
L3. Loss due to moisture in fuel (H2O)
L4. Loss due to moisture in air (H2O)
L5. Loss due to carbon monoxide (CO)
L6. Loss due to surface radiation, convection and other unaccounted.
L7. Unburnt losses in fly ash (Carbon)
L8. Unburnt losses in bottom ash (Carbon)
Boiler Efficiency by indirect method,
= 100 – (L1 + L2 + L3 + L4 + L5 + L6 + L7 + L8)

14. FACTORS AFFECTING BOILER PERFORMANCE
 Periodic cleaning of boilers
 Periodic soot blowing
 Proper water treatment programme and blow down control
 Draft control
 Excess air control
 Percentage loading of boiler
 Steam Generation pressure and temperature
 Boiler insulation
 Quality of fuel

15. ENERGY PERFORMANCE ASSESSMENT OF FURNACES
 To find out the efficiency of the furnace.
 To find out the Specific energy consumption.
 The purpose of the performance test is to determine efficiency of the furnace and specific energy
consumption for comparing with design values or best practice norms. There are many factors affecting
furnace performance such as capacity utilization of furnaces, excess air ratio, final heating temperature
etc. It is the key for assessing current level of performances and finding the scope for improvements and
productivity.

16. EQUATIONS

17. DIRECT METHOD TESTING
 The efficiency of the furnace can be computed by measuring the amount of fuel consumed per unit weight of
material produced from the furnace.
 Thermal efficiency of the furnace =
 (Q) to the stock can be found from the formula Q = m x Cp (t2 – t1)
 Where Q = Quantity of heat in kCal
 m = Weight of the material in kg
 Cp = Mean specific heat, kCal/kg°C
 t2 = Final temperature desired, °C
 t1 = Initial temperature of the charge before it enters the furnace, °

18. INDIRECT METHOD TESTING
 Similar to the method of evaluating boiler efficiency by indirect method, furnace efficiency can also be
calculated by indirect method. Furnace efficiency is calculated after subtracting sensible heat loss in flue
gas, loss due to moisture in flue gas, heat loss due to openings in furnace, heat loss through furnace skin
and other unaccounted losses from the input to the furnace. In order to find out furnace efficiency using
indirect method, various parameters that are required are hourly furnace oil consumption, material
output, excess air quantity, temperature of flue gas, temperature of furnace at various zones, skin
temperature and hot combustion air temperature. Efficiency is determined by subtracting all the heat
losses from 100.

19. FACTORS AFFECTING FURNACE PERFORMANCE
 The important factors, which affect the efficiency, are listed below for critical analysis.
 Under loading due to poor hearth loading and improper production scheduling
 Improper Design
 Use of inefficient burner
 Insufficient draft/chimney
 Absence of Waste heat recovery
 Absence of Instruments/Controls
 Improper operation/Maintenance
 High attack loss
 Improper insulation/refactories

20. ENERGY PERFORMANCE ASSESSMENT OF
 The purpose of the cogeneration plant performance test is to determine the power output and plant
heat rate. In certain cases, the efficiency of individual components like steam turbine is addressed
specifically where performance deterioration is suspected. In general, the plant performance will be
compared with the base line values arrived at for the plant operating condition rather than the design
values. The other purpose of the performance test is to show the maintenance accomplishment after a
major overhaul. In some cases the purpose of evaluation could even be for a total plant revamp.

21. EQUATIONS

22. EQUATIONS

23. EQUATIONS