Coupling Optimization For Air Source Heat Pump And Auxiliary Electric Heating Combined Heating System

With the rapid development of China’s economy,the total energy consumption of the society has gradually increased,of which building energy consumption accounts for nearly one-third.Among the building energy consumption,China’s current urban heating energy consumption in the northern region accounts for 22%,which is one of the main sources of building energy consumption.In the northern heating period,coal-fired heating is used in the north,which emits a large amount of atmospheric pollutants such as exhaust gas,dust and small particles.Coal-fired heating has increased air pollution by about 20%,driving the emergence of haze and environmental problems.The air source heat pump heating system has the advantages of wide application range,high efficiency,energy saving,clean and environmental protection.It has a positive effect on energy saving and emission reduction.The combination of air source heat pump and floor radiation for low temperature heating is characterized by high efficiency,stability and environmental protection.However,the significant disadvantage of the air source heat pump unit is that the supply and demand do not match.During the whole heating period,as the outdoor temperature decreases,the indoor heat load demand gradually increases,and the unit heat capacity of the unit gradually decreases.In order to solve this contradiction,it is usually necessary to add auxiliary electric heating equipment to improve the operation reliability of the heat pump unit.When the proportion of the heat load of the floor radiant heating system occupied by the air source heat pump is larger,the energy saving of the entire heating system is better,but the initial investment is larger.On the contrary,the initial investment of the whole heating system is lower,but the energy saving is poor.Since the radiator heating system generally requires a higher water supply temperature,the air source heat pump can generate hot water generally not exceeding 50 ° C,which cannot meet the needs of radiator heating.For the air source heat pump radiator heating system,it is necessary to increase the auxiliary electric heating equipment to increase the water supply temperature to meet the system heating demand.When the water supply temperature of the air source heat pump radiator heating system is lower,the proportion of the entire heating heat load undertaken by the air source heat pump is larger,and the auxiliary electric heating equipment bears a relatively small heat load.At this time,the whole system has better energy saving,but the initial investment is high.On the contrary,the initial investment of the whole system is lower,but the energy saving is poor.In order to comprehensively evaluate and optimize the coupling mode of two kinds of composite heating systems from the aspects of energy conservation and economy,the concept of unit price energy efficiency coefficient is proposed.The unit price energy efficiency coefficient indicates the energy saving situation under the system unit price.The higher the unit price energy efficiency coefficient of the system,the better the energy saving of the system at the same price,and the higher the cost performance.On the contrary,it means that the system is less energy-efficient at the same price,and the lower the price/performance ratio.In this paper,TRNSYS is used to construct a simulation model of composite heating system based on both the floor radiation and the radiator.Experiments were carried out by setting up a test bench,and the experimental data was compared with the simulated data to verify the accuracy of the simulation model.For air source heat pump and auxiliary electric heating floor radiant heating system,this paper comprehensively analyzes the energy conservation and economy of residential,shopping malls and office buildings in three different cities of Taiyuan,Zhengzhou and Jinzhou,and the unit price energy efficiency coefficient was used as an indicator to evaluate it.The results show that for the air source heat pump and auxiliary electric heating floor radiant heating system of residential buildings in Taiyuan,Zhengzhou and Jinzhou,when the air source heat pump units account for 60%,60% and 75% of the heat load of the entire heating design,the unit price energy efficiency coefficient is the highest;for the air source heat pump and auxiliary electric heating floor radiant heating system of shopping malls in Taiyuan,Zhengzhou and Jinzhou,when the air source heat pump unit accounts for 60%,60%,60% of the total heating design heat load,the system unit price energy efficiency is the highest;for the air source heat pump and auxiliary electric heating floor radiant heating system of the office building in Taiyuan,Zhengzhou and Jinzhou,when the air source heat pump unit accounts for 60%,60%,60% of the heat load of the entire heating design,the unit price energy efficiency coefficient is the highest.For air source heat pump and auxiliary electric heating radiator h eating system,this paper comprehensively analyzes the energy conservatio n and economy of residential buildings in three different cities of Taiyuan,Zhengzhou and Jinzhou,and the unit price energy efficiency coefficient was used as an indicator to evaluate it.The results show that for the air source heat pump and auxiliary electric heating radiator heating system of residential buildings in Taiyuan,Zhengzhou and Jinzhou,when the designe d supply water temperature is 60/35°C,the system unit energy efficiency coefficient is the highest.That is to say,the best energy saving effect at the same price,the highest cost performance.