Research On The Configuration Of Congeneration System Based On Waste Heat Recovery Of The Air Cooling Plant

With the increase of the heating energy consumption in the northern towns of our country, “clean-heating” and “energy conservation and emissions reduction” have become an important task of energy supply business. The cogeneration units improve the efficiency of heating and environmental protection. However, a lot of condensing waste heat existed in units at the run time has not been used. In the field of CHP, even the thermal power generation, building clean-heating system based on condensing waste heat recovery is imperative, and is an important direction. Aimed at air cooling units, this paper establish an organic combination among the three technical route-“high back pressure”, “heat pump” and “low temperature backwater of the heat network”, then puts forward a new kind of cogeneration heating system based on condensing waste heat recovery, recovering waste heat in depth, increasing energy efficiency and improving the feasibility of the project. This paper focuses on the integration configuration of the new system process, clearing the optimization direction of technology. The research will be used for guiding the system integration design.(1) According to the safe operation of the large-scale units cause by the waste heat recovery, this paper presents the calculation method of “minimum flow rate of cooling” through the analysis of security feature index of the last stage long blade, and indicates the choice basis of extraction steam and back pressure under condition of safety. In view of the energy efficiency of the cogeneration system cause by the waste heat recovery, through the analysis of effect of extraction and exhausted steam parameters on the unit capacity(heating and power generation), this paper introduces the “equivalent electric of heating”, providing the analysis standards of energy efficiency. Both of the work provide necessary theoretical basis for the configuration optimization of the new system.(2) For two unit air cooling units, this paper establishes an organic combination among the “high back pressure”, “heat pump” and “low temperature backwater of the heat network”, and then constructs a cascade heating process of backwater based on waste heat recovery. The added “bypass water” can regulate the “back pressure” and “heat pump capacity”. The new system constructs a cascade heating process with exhausted steam, heat pump, extraction steam, achieving higher energy efficiency of the system. After that, This paper established a mathematical calculation model of the new system, which provides the theoretical foundation for the integrated configuration.(3) In view of integration configuration of the new process based on different heat pumps, at different ratio of extraction and exhausted steam and different bypass water flow, this paper research the effect of changes of important system parameters on the system configuration, energy efficiency and economy further, clearing the optimization direction of the new system performance and makes the “high back pressure” and “heat pump” achieve the best match. On this basis, this paper optimizes the ratio of extraction and exhausted steam between the units, realizing the energy cascade utilization, then achieves better system efficiency.(4) Take Xing Neng Gu Jiao power plant in Shanxi Province as an example, this paper design comparison schemes of waste heat recovery. Through the analysis of energy efficiency and economic benefit, this paper proves the advantage of new system on energy efficiency and economic, verifying the actual application significance of research content.