Energy Saving Research Of Combined Cooling, Heating And Power System Based On Absorption Refrigeration

This paper builds the mathematical model of the three electric energy supply systems: Combined Cooling,Heating and Power system(CCHP),Combined Heating and Power system (CHP) with independent electric refrigeration,and independent Heating,Cooling and Power system(IHCP).From the view of primary energy consume and primary energy consume ratio, it analyses energy saving property of the CCHP system;then it analyses the characters of the energy efficiency and energy consume;Finally,it has studied and discussed the cost allocation system of thermoelectric cogeneration.From the system point of view,the refrigeration system equivalent coefficient used as an evaluating indicator of the cogeneration refrigeration system energy saving is carried out. Based on relevant documents and theoretical analysis,a formula for calculatingμvalue of CCHP is educed.It is concluded that variable is influenced by steamμparameters of steam turbine,such as inlet steam pressure and temperature,extraction pressure and temperature,or backing pressure.And it is pointed out thatμvalue essentially is the allocation proportion of energy among heating,power and cooling in CCHP system.After the calculating of primary energy consumption and equivalent thermodynamic coefficient between absorption refrigeration and electric compression refrigeration systems,it concludes that energy saving performance in refrigeration system of CCHP is related to COP coefficient of performance of refrigerator and the parameters.The mathematical models of the primary energy consumption is built based on the comparison model between cogeneration and dividend system,by choosing a different type of back-pressure steam turbine,utility boiler and lithium bromide refrigerator,they make up the CCHP system and make calculation,comparison and analysis to the energy-saving compared to CHP system from the primary energy consume and primary energy rate aspects.The result indicates that CCHP system is energy-saving compared to CHP system.And if the steam turbine is backpressure,the amount of energy saving is larger.The major factors which influence the energy saving of CCHP system are as following:①capacity and steam parameters of steam turbine;②coefficient of performance of refrigerator;③heating load rate;④average national heat generating electricity efficiency.Attempting to discuss the efficiency changes regularity of the CCHP system in the partial load and in a smaller run-time load,then through the calculating and analysis of the total energy efficiency of cogeneration system under different loads,we found that:the CCHP system is not all in a state of high energy-efficient,and the power efficiency and total efficiency decline with generate electricity capacity.Later,we analysis and study the energy consumption features,and build the condition expression model of cogeneration system energy saving from the system the primary energy consume and primary energy saving rate. The model was validated with actual plant performance data.The impacts of the changes in various factors(ratio of heat to power,energy utilization factor and absorption chiller COP) on the energy conservation of tri-generation were investigated in detail.The research indicates that,the necessary condition need satisfied on the thermoelectric and it's heating,cooling and power cogeneration.Relatively speaking,combining cooling and power generation is stricter than that for heating and power cogeneration.Targeting several existing common problems in cogeneration system and by way of multi-layer analysis,the author has come up with a new conception of apportionment;from the stave using of energy,a new method for cost allocation is proposed based on the Exergy method and the reduced Exergy method,and mathematical model of Exergy loss method is obtained.