Cogeneration Systems

Cogeneration, also referred to as combined heat and power (CHP), is the simultaneous generation of both electricity and useful heat. In a normal setting where there is electrical production, thermal energy (heat) typically gets rejected as waste heat. In cogeneration however, this thermal energy is used to maximize fuel efficiencies. Cogeneration Designs can greatly reduce operating costs while dramatically increasing system efficiencies.

Mandates and efficiency demands are constantly changing, and alongside, rebates and incentives are also changing. In today's world of uncertain rising costs, a cogeneration plant can help reduce the associated financial risks of energy and heating expenses. Consult with EMCo Systems Solutions to get a better understanding of how Cogeneration can maximize your system's efficiencies. EMCo has the experience and knowledge to deliver the best Cogeneration Solutions that are suited for your specific available resources and needs.

Types of Cogeneration Plants

Large cogeneration systems provide heating water and power for an industrial site or an entire town. To understand cogeneration here are two types of Cogeneration Plants Topping Cycle plants and Bottoming Cycle plants.

Topping cycle plants primarily produce electricity from a steam turbine. The exhausted steam is then condensed and the low temperature heat that is released from this condensation is utilized for local district heating purposes.

Bottoming Cycle plants start with the production of high temperature heat for industrial processes, which then applies a Waste Heat Recovery System to feed an electrical plant, usually an ORC Turbine. Bottoming cycle plants are more typically used when the industrial processes require very high temperatures such as furnaces for glass and metal manufacturing, so they are less common. A recent development to facilitate the production of electricity from Low-Grade waste heat is through the development of the Elecratherm Green Machine. Process facilities can now produce electricity from Waste Heat Recovery System with temperatures of only 240 farenheit or greater. Below is a diagram of a Bottoming Cycle Cogeneration System with an Electratherm Green Machine.

The same by-product heat from electrical generation used for heating purposes can also be used in absorption chilers for cooling at more moderate temperatures (212-356°F/100-180°C). A plant producing electricity, heat and cold is sometimes called Trigeneration or more generally, a Polygeneration plant. Trigeneration designs can allow versatile system applications. Cogeneration and Trigeneration designs can administer an unparalleled return on investment in as little as 3 to 5 years.

Learn more about Waste Heat Recovery from the ElectraTherm Green Machine

Common Cogeneration Plant Types

Gas Turbine CHP plants using the waste heat in the flue gas of gas turbines. The gaseous fuel used is typically natural gas

Gas engine CHP plants use a reciprocating gas engine which is generally more competitive than a gas turbine up to about 5 MW. The gaseous fuel used is normally natural gas.

Biofuel engine CHP plants use an adapted reciprocating gas engine or diesel engine, depending upon which biofuel is being used, and are otherwise very similar in design to a Gas engine CHP plant. The advantage of using a biofuel is one of reduced hydrocarbon fuel consumption and thus reduced carbon emissions. Another variant is the wood gasifier CHP plant whereby a wood pellet or wood chip biofuel is gasified in a zero oxygen high temperature environment; the resulting gas is then used to power the gas engine.

Combined cycle power plants adapted for CHP is an assembly of heat engines that work in tandem off the same source of heat, converting it into mechanical energy, which in turn usually drives electrical generators. The principle is that the exhaust of one heat engine is used as the heat source for another, thus extracting more useful energy from the heat, increasing the system's overall efficiency. 

Let EMCo know how we can help