| At present,coal-fired power generation is still the main form of power generation in China.Most of China's thermal power plant is used in closed circulating water cooling system,not only need a lot of circulating water in the cooling tower cooling steam turbine exhaust,and will cause a large number of circulating water loss and heat loss,heat loss is about 60% of the total heat loss.However,as the temperature of circulating water is too low,it is often discharged directly,which not only wastes the resources,but also destroys the ecological balance.With the maturity of technology such as heat pump and heat pipe,lo w quality waste heat is reused and become a necessary trend of energy saving.Therefore,the recovery of low quality waste heat has become an important part of energy saving and consumption reduction in China's power industry.This article first introduces the analysis of the utilization of one energy in the world and in our country,and understand that our country faces the threat of energy is very serious,and the characteristics of circulating water of power plants in China were analyzed using T-S epigram theory to analyze the evaporation temperature of heat pump(water temperature)and condensing temperature(user recovery temperature)effect on the performance of heat pump;according to the quality and flow rate is proportional to the impact analysis the water flow side and user side flow on the performance of heat pump.Secondly,the waste heat utilization is divided into two different utilization types in winter and transition season,and the effects of different working conditions on heat pump energy consumption and COP are analyzed.In winter conditions,1)transverse analysis of the experiment shows that,with the increase of circulating water temperature,the evaporating temperature of the evaporator increases,the heat absorption increases,the external heat release increases,and the heat pump COP increases.2)on the longitudinal comparison,in the circulating water temperature,with the increase of circulating water pump import temperature,evaporating pressure evaporator decreases,no evaporation temperature decreased,reducing heat absorption heat pump,heat pump condenser parameters remain unchanged,the heat pump compressor heat pump power consumption increases,COP decreases.In the transition conditions,The feasibility of water source heat pump for reclaiming waste heat in a power plant and the effect of heating process on heat pump COP and energy consumption are analyzed.With the deepening of the heat pump heating,the water temperature in the tank by 25? gradually increased to 55?,condenser pressure and temperature increasing,which leads to the compressor power consumption increases,because the evaporator parameters remained unchanged,the condensation of refrigerant pressure is far higher than the evaporation pressure in the heating process with throttling loss elevated temperature of water in the water tank is increasing,COP decreases gradually with increasing temperature of water in the water tank.Again,through the water pump experiment further analysis found that the circulating water temperature increases,the evaporation pressure decreases constantly,invariant condenser parameters,the outlet of the compressor pressure ratio increases,and the power consumption of the compressor increases rapidly to reduce faster rate than the energy consumption of water pump and lead to COP of heat pump system in the circulating water temperature increases that first increases and then decreases,the circulating water temperature difference of 7?,the maximum coefficient of performance of heat pump system.So the circulation water temperature difference heat pump is not the greater the better the temperature difference,the circulation water temperature difference at 7-9?,the heat pump operation is the most energy-saving. |
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