Cogeneration-its definition and its application

1. COGENERATION
PresentedBy:
PRUTHIRAJ SWAIN(12PS21F)

2. Definition :

Cogeneration is the simultaneous generation in one process of
thermal energy and electrical and/or mechanical energy;

Useful heat is heat produced in a cogeneration process to satisfy
an economically justifiable demand for heating or cooling;
 The heat produced by cogeneration can be delivered through
various mediums, including warm water (e.g., for space heating
and hot water systems), steam or hot air (e.g., for commercial and
industrial uses).
 It is also possible to do Trigeneration, the production of
electricity, heat and cooling.
 Trigeneration is an attractive option in situations where all three
needs exist, such as in production processes with cooling
requirements.

3. Cogeneration technologies

Combined cycle gas turbine with heat
recovery

Steam backpressure turbine

Steam condensing extraction turbine

Gas turbine with heat recovery

Internal combustion engine

Micro turbines

Sterling engines

Steam engines

Fuel cells

ORC

4.  Other classifications:
Topping cycle
Bottoming cycle

Cogeneration units:

Micro-cogeneration means below 50 kWe;

Small-scale cogeneration means below 1 MWe.

Power to heat ratio (P/H):

the ratio between electricity from cogeneration and
useful heat when operating in full cogeneration mode

5. Efficiency coefficient for heat generation
only
Fuel type Overall
efficiency
Solid fuels Hard coal/coke 0.88
Peat 0.86
Wood fuels 0.86
Oil, LPG 0.89
Biofuels 0.89
Natural gas 0.9
Biogas 0.7

6. Efficiency coefficient for electricity
generation only
Fuel type Overall
efficiency
Solid fuels Hard coal/coke 0.442
Peat 0.390
Wood fuels 0.330
Oil, LPG 0.442
Biofuels 0.442
Natural gas 0.525
Biogas 0.420

7. Alternatives for heat and electricity supply
Condensing power plant
Electricity
CHP
Electricity
Heat energy
Heat energy
Boiler house

8. Where can CHP be Economically
Attractive?
Data Centers Nursing Homes
Colleges & Universities Office Buildings
Ethanol/ Biofuel Process Large Multi-Family
Plants Apartments
Food Processing Plants Refrigerated Warehouses
Hospitals Restaurants
Hotels Supermarkets
Ice Arenas Theatres
Chemicals, Pulp & Paper, Greenhouses
Fabricated Metals, Plastics Wastewater Treatment
Facilities

9. Why is There an Opportunity?
 Rising Concerns Over
 – Blackouts/Brownouts
 – Power Supply Constraints
 – Marked Increases in Electricity & Fuel Prices
 Selected Power Outage Costs

10. Generators
Two Types of Generators
Induction Synchronous
• Requires Grid Power • Self Excited (Does
Source to Operate Not Need Grid to
Operate)
• When Grid Goes
Down, CHP System • CHP System can
Goes Down Continue to
Operate thru Grid
• Less Complicated & Outages
Less Costly to • More Complicated &
Interconnect Costly to
• Preferred by Utilities Interconnect (Safety)
• Preferred by
Customers

11. CHP Recycles the Waste Heat from Power
Generation achieving efficiencies of over 80%.

12. CHP and separate generation
Fuel input Output Fuel input
Separate
generation CHP
Power station Electricity Electricity
81 35%
43% 35
100
Useful heat
53 Heat
Boiler house 50%
50
95%
Total 134 Total 100
134 − 100
Primary energy savings = = 25%
134

13. Benefits of CHP
High Efficiency, On-Site Generation Means :
 Improved Reliability.(Avoiding business disruptions)
 50% less CO2 emissions.(Monetizing Environmental benefits)
 Up to 80% energy efficient.(Reducing Fuel use)
 Removes requirement for back-up diesels (Conserve Natural Resources)
 Can uplift Green Star ratings by 1-2 stars.
 Usually cost-effective.
 Support Grid Infrastructure
 Fewer T&D Constraints
 Defer Costly Grid Upgrades
 Price Stability
 Facilitates Deployment of New Clean Energy Technologies

14. Environmental benefits
250
200
150
W
100
O
h
C
2
k
/
50
O mo
h
n
C 2e
a
g
y
s
r
t
f
,
i
0
2005 2006 2007 2008 2009 2010 2011 2013 2015 2018 2020

CO2 emissions reduced by 75%-90% (44-54 thousand Tonnes/year)

Overall efficiency in CHP mode – 89%

15. Efficiency Benefits of CHP

16. Environmental Benefits of CHP
(NOx)

17. Conclusion:
The main reasons for higher specific energy
consumption in Indian Industries are obsolete
technology, lower capacity utilization and poor
operating and maintenance practices.
EC has received increased attention in India since
the mid seventies but its impact is felt at a low
face due to inhibiting attitudes, insufficient
technical know-how, market distortions, high cost
of efficient end use devices, capital shortage etc.
There is a need to design interventions in terms
of policies and institutions which addresses these
issues and create incentives for energy
conservation.

18. THANK YOU