Study On Characteristics Of The Heat Pump Heating System With Seasonal Thermal Storage Of The Condensed Waste Heat Of The Cogeneration Plant

With the continuous expansion of distract heating scale and the rapid growth of people’s livelihood heating demand in China,the problems of insufficient heating capacity of existing heat sources and environmental pollution caused by large-scale coal-fired heating have become increasingly prominent.It is an important task to tap the heating potential of existing heat sources and vigorously promote the application of clean heat sources represented by soil sources.Based on this,this paper proposes a new type of exhaust steam waste heat-hot water absorption ground source heat pump system based on seasonal soil storage of power plant waste heat.And carried out research on the characteristics of the heat exchange variable conditions of the system,hoping to provide a reference for the further optimization analysis and application of the system.Firstly,aiming at exploring the energy-saving potential of system heating,under the guidance of the second law of thermodynamics,the irreversible rake losses existing at the heat source,heat station and the end of heating equipment of conventional cogeneration central heating system are quantitatively analyzed,and its energy-saving potential is discussed.The measures to reduce the return water temperature of primary network are analyzed.Based on this,a new system is put forward,and the thermodynamic perfection of the new system is analyzed,and the advantages of the new system are pointed out.For the construction of system mathematical model,the calculation models of absorption heat pump,water-water heat exchanger and buried pipe heat exchanger are established;the energy consumption evaluation model of "heating equivalent electricity" is introduced;the environmental protection evaluation model of greenhouse gas and pollutant discharge per unit of heat supply is introduced;and the economic evaluation model of incremental investment recovery period is taken as the important basis for system evaluation.Aiming at the heat exchange characteristics of the new system and with the goal of reducing the heat consumption of the new system,the effects of circulating water flow rate,number of water collector connections at the source and side of soil,inlet and outlet temperature,soil heat storage temperature and heating distance on the comprehensive heat consumption of the new system are analyzed.The optimization direction of heat exchange characteristics under variable operating conditions for the new system is indicated.Taking actual engineering case as an example,the feasibility of the new system is verified by comparing the new system with the conventional system from three aspects:energy conservation,environmental protection and economy.