CoGen - Cogeneration in water boiler cycles 


The innovative CoGen co-generation system is designed for heating cycles in water-pipe boilers for the production of combined heat and power. The dry water vapor produced in the process of isentalpic throttling, superheated in the exhaust stream, supplies a steam condensing turbine that generates power to drive the power generator. The return water from the external distribution is directed to the cooling of the wet steam in the condenser after the condensing turbine. The applied solutions ensure reduction of thermal losses to the environment and increase of efficiency of the heating cycle with cogeneration. The cogeneration installation is external to the water pipe, and the technological connection system does not limit boiler operation.


Characteristics of the investment for the WR-25 boiler under constant fuel consumption conditions:

  • In the WR25 boiler without cogeneration, the heat output of 29MWt is generated with the efficiency of the boiler room and the efficiency of the boiler is 84%.

  • In a cogeneration unit (boiler WR25 with cogeneration), a thermal power of 27.75 MWh is produced and electrical power 2.41MWe with a co-generation factor fc = 2.41 / 27.75 = 0.087 with boiler efficiency and cogeneration efficiency 88.84%> 80% which fulfills the condition of generating electricity in cogeneration and applying for the award of red certificates.

  • The use of waste energy (exhaust gas heat 1.95MWt and condensate condensate heat 8.75MWt) creates the conditions for applying for white certificates.


Economic comparison of cogeneration and heating plant efficiency:

  • Heat sales revenues / fuel costs = 170.85%

  • (revenues from the sale of heat + avoided costs of electricity) / fuel costs = 191.68%


The estimated simple payback period for modernization expenditures is 1.9 years.