The CHP System Energy Analysis And Optimized Reconstruction Research Based On Energy Quality Character

CHP is an important way of realizing energy cascade utilization. It has a positive significance to the energy conservation and CO₂ emission reduction so as to achieve a low carbon society. In this paper, the current situation, national policies and prospects of CHP at both home and abroad were discussed. Based on the actual operation CHP system in Tianjin Guohua energy Co., Ltd, this paper did the heat economic analysis and exergy analysis to this CHP system. And specific to the example of Tianjin Guohua CHP, the direction and measures of optimizing energy saving reconstruction to this system were pointed out in this paper.In this paper, it introduced the main heat economic indicators in CHP system and three allocation methods between heat and power in total heat consumption, and according to the allocation methods, we can get the partial heat economic indicators of heat and power. This paper calculated the heat economic indicators of the main energy equipments in Guohua CHP system, and analyzed the potential of energy saving. It pointed out that low energy efficiency of the boiler and low relative internal efficiency of the steam turbine, excessive use of temperature and pressure reducer, and large energy consumption of electric feed pump are the main disadvantages to these small CHP systems. So the enterprise reconstructed the condensing turbine with extraction to back pressure turbine, and electric feed pump to Steam feed pump to improve its economy.In this paper, the concept of the Energy quality character was introduced, and the Energy quality character of main form of energy are ensured. Based on it, the exergy evaluation method of energy system was proposed, the general formula among energy coefficient, exergy efficiency and Energy quality character was got, and the general basis principles that reasonable energy use should be followed was refined out. According to the exergy analysis, this paper did the exergy analysis calculations to the main equipment in Guohua CHP system, and ensured the equipment of big energy consumption and big exergy consumption to provide the theory basis for the optimization energy saving conformation of system.Finally, the main difficult and the direction of reconstruction and development of small and medium CHP were discussed, and according to it, the improvement effect of condensing turbine with extraction to back pressure turbine, electric feed pump to Steam feed pump, and condensation water recycle use were analyzed in this paper. This paper pointed out that condensing turbine with extraction and back pressure turbine should be operation rationally matched, and strengthen condensation water recycle use. At the same time, this paper suggests installing small rearwards back pressure turbine to achieve the heat cascade utilization.