What is Combined Heat and Power (cogeneration)
Cogeneration or Combined Heat and Power (CHP) Technology converts gas into both electricity and heat in a single process at the point of use.
How Does Cogeneration Work
Cogeneration uses a single process to generate both electricity and usable heat or cooling. The propositions of heat and power needed (Heat: Power) vary from site to site, so the type of plant must be selected carefully and an appropriate operating regime must be established to match demands as closely as possible.
Cogeneration System consists of four elements
- A primary mover (engine)
- An electricity generator
- A heat recovery system
- A control system
Suitability of Cogeneration
Cogeneration has long history of use in many industries. In recent years the greater availability and wider choice of suitable technology has meant that cogeneration has become an attractive and practical proposition for wide range of industries. These include the process industries, commercial and public sector buildings and district heating schemes, all of which have considerable heat demand. We also lists renewable fuels that can enhance the value of cogeneration, although fossil fuels, particularly natural gas and more widely used
- Pharmaceuticals
- Paper and board manufacture
- Brewing, distilling & malting
- Ceramics
- Brick
- Cement
- Food Processing
- Textile Processing
- Minerals Processing
- Oil Refineries
- Iron and Steel
- Motor Industry
- Horticulture and glasshouses
- Timber Processing
Buildings
- District Heating
- Hotels
- Hospitals
- Leisure Centers
- Airport
- Prisons
- Supermarkets
- Office Buildings
- Individual Houses
Renewable Energy
- Sewage treatment works
- Poultry and other farm sites
- Short rotation coppice woodland
- Energy cops
- Agro-wastes
Energy From Waste
- Gasified Municipal Solid Waste
- Municipal Incinerators
- Landfill sites
- Hospital waste incinerators
Future of Cogeneration
Cogeneration is well proven-technology, recognized world wide as a cleaner alternative to traditional centralized generation. Its long-term future in the global energy markets is secured by its ability to provide operational financial and environmental benefits from a single unit of fuel.
Benefits of Cogeneration
Operational Advantages:
- Base load electricity supply
- Security of supply
- Legislative compliance of EBPD
- Increased diversity on heating and hot water
- Steam raising capabilities
- Trigeneration, using absorption mechanical chillers for cooling
Environmental Advantages
- Improved fuel efficiency
- Reduced CO2 emissions
- No Transmission Losses
- Reduction of energy consumed
- Lower SOx emissions with the use of natural gas a fuel
Operational Advantages
- Base Load electricity supply
- Security of supply
- Legislative compliance of EBPD
- Increased diversity on heating and hot water
- Steam raising capabilities
- Trigenration, using absorption/mechanical chillers for cooling
When to consider Cogeneration Technology
- Designing a new building
- Installing new boiler plant
- Existing site re-development
- Continuity of power
- Increasing energy efficiency
- Improving Financial Performance
- Positive environment impact
- Supporting the Company’s Green Image
Cogeneration Solutions and Technology Providers
There are various companies in the UK and Europe providing Cogeneration solutions and technologies. Below we have listed a few leading Cogeneration, Renewable Energy and Energy Management services provider
1. Ener.G Group
Most of these companies provide wide range of cogeneration solutions both in terms of the technology and procurement options available.
Cogeneration Technologies
Cogeneration Systems are available from 33W to 100MG typical applications run on natural gas, however system can also be fuelled by propane, biogas or diesel.
A typical cogeneration system consists of an engine, steam turbine, or combustion turbine that drives an electrical generator. A waste heat exchanger recovers waste heat from the engine and/or exhaust gas to produce hot water or steam. Cogeneration produces a given amount of electric power and process heat with 10% to 30% less fuel than it takes to produce the electricity and process heat separately.
There are two main types of cogeneration techniques: “Topping Cycle” plants, and “Bottoming Cycle” plants.
A topping cycle plant generates electricity or mechanical power first. There are four types of topping cycle cogeneration systems.
1. The first type burns fuel in a gas turbine or diesel engine to produce electrical or mechanical power.
2. The second type of system burns fuel (any type) to produce high-pressure steam that then passes through a steam turbine to produce power.
3. A third type burns a fuel such as natural gas, diesel, wood, gasified coal, or landfill gas.
4. The fourth type is a gas-turbine topping system. A natural gas turbine drives a generator.
Bottoming cycle plants are much less common than topping cycle plants. These plants exist in heavy industries such as glass or metals manufacturing where very high temperature furnaces are used.
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Q-Online
http://www.articlesbase.com/environment-articles/what-is-combined-heat-and-power-cogeneration-135429.html
What is the difference between a cogeneration power plant and a combined cycle power plant?
I understand the two process can be combined and used together; is cogeneration when waste heat is recovered and combined cycle is when heat is an intended component of the process (instead of a waste that is utilized)? There has to be something I’m missing here… Thanks much in advance!!
I suggest looking at the these pages… I don’t know how reliable Wikipedia is but it may be worth the look…
http://en.wikipedia.org/wiki/Cogeneration
http://en.wikipedia.org/wiki/Combined_cycle_power_plant
References :
Combined cycle is a term applied to gas turbine generators in which the exhaust heat from the gas turbine is used to produce steam (in a heat recovery steam generator - HRSG), which is then fed to a steam turbine.
The steam turbine may be on the same shaft as the gas turbine generator, or it may be a completely separate steam turbine & electrical generator.
Cogeneration is when the heat produced from a combustion process is split between electrical generation and industrial process steam.
The ‘combustion process’ can be either a boiler or a gas turbine with HRSG. The ‘industrial process’ steam can be for truly industrial chemical processes, or it could be for non-industrial steam plants, such as campus heating & cooling.
In summary, “combined cycle” refers specifically to a gas turbine generator with an exhaust-heated steam turbine generator to increase overall power plant efficiency. “Cogeneration” is making heat through whatever means, and dividing the heat energy between electric generation and other process needs.
References :
Electric power engineer