| With the intensification of the world’s energy crisis,the enhancement of environmental protection,energy conservation and emission reduction technology are increasingly valued,so new energy development paths must be found.The low-level waste heat resources in severe cold areas are very abundant but not fully recycled.Although the industrial sector has a large amount of low-grade waste heat,the utilization rate is still low during the low-grade waste process.In response to this problem,the cooling cycle of the Cold Cooling Circulating Circulating Water Rooping Project in Anshan Steel Cold Rolling Work is studied.The key technologies of low-quality heat utilization are studied,including the modeling and energy efficiency analysis of double-effect lithium bromide absorbent heat pumps,establishing a complete optimization configuration method and exergy analysis of heating system,which not only solves the phenomenon of energy waste,but also provides a reference for central heating in severely cold regions.The main research contents are as follows:Based on the principle of temperature pairing and step utilization,the thermal analysis of the vapor type dual-efficiency lithium bromide is thermally analyzed through the mathematical model of heat pump unit established by conservation of mass and energy,and the results calculated by compared with the process method,the heat pump is compared.The average error rate of the equipment load is 0.1%,and the performance coefficient error rate is 0.4%,indicating the accuracy of the numerical model of the heat pump unit.Analysis of the three external factors of hot mesh water supply temperature,evaporator waste heat water inlet temperature and driving heat source temperature.The numerical calculation results show that when the heat source temperature is driven,the hot mesh water supply temperature is about 49℃.The heat pump system COP is preferably 2.677;the evaporator inlet low temperature heat water temperature is about 47℃,the heat pump system COP is preferably2.682,the results of the study show that appropriate adjustment of the evaporator imported heat water temperature can make the performance of the absorbent heat pump better.Taking a hot-heat cell as an example,based on the mathematical model of the absorbent heat pump unit,the heat load dynamic changes of heat-transport residential building through Dest simulation,combined with hot mesh water supply temperature,residual heat water temperature on system performance affects curve fitting functions,the target function is established with the minimum steam consumption,and the capacity configuration of the unit is optimized.The optimization results show: 2 capacities of 3490 k W absorbent heat pump units are the optimal unit configuration.By comparison,the configuration scheme saves 88 t steam consumption than five absorption heat pumps with capacity of 1160 k W and saves787,097 yuan annual cost than three absorption heat pumps with capacity of 2330 k W.The project of absorption of heat pump recovery waste heat,according to the exergy analysis method,combined with the established thermodynamic model of evaporator,condenser,absorber,solution heat exchanger,generator,calculate the efficiency of the order,dual-efficiency absorption heat pump system respectively.The results show that the double-effect absorbent heat pump is 3.7% higher than the single-active absorbent heat pump.The economic analysis of absorbent heat pump recovery waste heat water and conventional gas boiler plan showes that the investment recovery period of the absorbent heat pump was about 2.92 years,and the boiler system was in a loss.The equivalent net annual value of the absorbent heat pump was 3.137 million yuan,and the boiler system is-40.593 million,consequently,the economy of the absorbent heat pump is best.When the heating area in the cold regionis large,the number of installed absorbent heat pumps is less,and the area of equipment room is small.Therefore,the absorbent heat pumps are preferred as heat sources for central heating items. |
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