Screw Two-stage Condenser Performance Study Of Air Source Heat Pump Heating System

The screw type two-stage condenser air source heat pump heating system is a new type of air source heat pump system.The screw compressor heat pump use jet enthalpy technology,that make the air source heat pump unit can still work properly when the outdoor environment is lower than minus 25 degrees Celsius.The two-stage condenser technology of this system is convenient for the air source heat pump system to adjust the operating quality according to the outdoor environmental conditions.The system has better energy saving than the traditional air source heat pump heating multipled system,and can effectively solve the problem of excessive operation cost of gas boiler under the policy of "coal to gas".In this paper,the screw type double stage condenser air source heat pump heating system analyzes the working principle and process in the actual construction process,to establish the mathematical model of the main components of the system,and the simulation model of the screw type two-stage condenser air source heat pump heating system was established using the TRNSYS simulation software,through the contrast verification the measured data and simulation data,prove the correctness of the simulation model.In this paper,the screw type two-stage condenser air source heat pump heating system only open a set of heat pump units at the beginning and end of cold period a optimize the operation scheme of cold to open the two sets of heat pump units,the simulation model validation after respectively simulate the operation of different circumstances of the whole heating period only run a set of heat pump units and always open two sets of heat pump units based on different conditions of system operation comfort and energy saving,so as to optimize the system operation mode.In addition,the difference of economy and energy saving between two heating systems of the screw type double stage condenser air source heat pump heating system and the traditional coal fired boiler and the hot steam boiler are compared.In this paper,the main contents and conclusions on the basis of actual data and simulation data as follows:(1)It establish the mathematical model of the building load and mathematical model of the main components in the screw two-stage condenser performance study of air source heat pump heating system,it provide theoretical support for the establishment of system simulation model;(2)According to the actual case installed a screw two-stage condenser air source heat pump heating system,the establishment of screw type double stage condenser air source heat pump heating system simulation model using TRNSYS software.Combined with the actual case of test data,compared with the simulation data by using the TRNSYS software to establish the simulation model,and analyze the reasons of the errors,the accuracy of the simulation model is proved,which can replace the actual condition;(3)It use TRNSYS software to establish the screw type two-stage condenser air source heat pump heating system simulation model,simulated operation of the heating system of a heat pump unit and has been running two sets of heat pump units in the case of the whole heating period,dynamic indoor temperature and the coefficient of performance analysis of the system,it can not meet the demand of heating time the only operation of a heat pump system,this time to open the second sets of pump unit time control logic.The optimization of the operation mode is based on the actual case of typical local meteorological parameters;(4)In this paper,the screw two-stage condenser air source heat pump heating system cold period and at the end of the cold in the early stage only open the level of heat pump units,the cold period of open operation scheme optimization of two-stage heat pump units,based on the simulation model is validated,then the whole heating period respectively runs only level 1 heat pump units and the whole heating period has been opened the different situation of two-stage heat pump units using TRNSYS software to run the simulation,analysis of system dynamic indoor temperature and the coefficient of performance,compare the comfort and energy saving of the system is under different conditions,it is concluded that only when run level of heat pump system can't meet the demand of heating period,this period of time to open the secondary time control logic of the heat pump units,so as to optimize system operation mode,based on the optimization of operation of taiyuan meteorological parameters on the basis of typical years,in which there are limitations.(5)In the annual cost of the economic analysis of the screw type double stage condenser air source heat pump heating system,and the traditional coal-fired boiler heating system with gas-fired boiler heating system of the initial investment cost,operation cost and annual cost were analyzed,considering the large temperature difference of screw type double stage air condenser source heat pump heating system the best economy.In addition,this paper calculates the primary energy consumption of three kinds of heating systems,and compares them with the standard coal consumption.Considering the two aspects of economy and energy saving,the large temperature difference screw type double stage condenser air source heat pump heating system is better than other heating systems.