Transcritical carbon dioxide air conditioning system for electric bus

Abstract

A transcritical carbon dioxide air conditioning system for an electric bus comprises a compressor, a three-way valve, an external heat exchanger, a first drying filter, a second drying filter, an internal heat exchanger, a gas-liquid separator and a heat regenerator, an outlet of the compressor is connected with a first connector of the three-way valve, and a second connector of the three-way valve is connected with an inlet of the external heat exchanger. A third connector of the three-way valve is connected with an inlet of the in-vehicle heat exchanger, one path of an outlet of the out-vehicle heat exchanger is sequentially connected with the first ball valve, the first drying filter, the in-vehicle heat exchanger, the gas-liquid separator, the heat regenerator and an air suction port of the compressor, and the other path of the outlet of the out-vehicle heat exchanger is connected with the gas-liquid separator. A pure natural environment-friendly CO2 refrigerant is adopted, the problem that a pure electric bus is low in heating efficiency in winter is solved, combined valves such as a pressure release valve and a ball valve are adopted, the situation that the system is blocked or abnormal high pressure of the system is caused under other abnormal conditions is prevented, and the heat regenerator in the system can effectively increase the suction superheat degree of the compressor and prevent liquid impact of the compressor.

Description

technical field [0001] The invention relates to the field of passenger car air conditioning, in particular to a transcritical carbon dioxide air conditioning system for electric buses. Background technique [0002] With the popularity of urban public transport and the support and subsidies of relevant national policies, there are more and more pure electric buses. Since there is no waste heat from the engine to use, at this stage we can only rely on PTC heaters or heat pumps to achieve the purpose of heating in winter, but PTC The efficiency of the heater is less than 1, which greatly increases the power consumption of the vehicle in winter and seriously reduces the cruising range; the working fluid of the heat pump system is R407C or R410A, and these two refrigerants are mixed refrigerants, which are not very environmentally friendly and In winter, the heating efficiency is lower than 2, and the ambient temperature can only work normally above -20 degrees Celsius, which can...

AI Technical Summary

Problems solved by technology

[0002] With the popularity of urban public transport and the support and subsidies of relevant national policies, there are more and more pure electric buses. Since there is no waste heat from the engine to use, at this stage we can only rely on PTC heaters or heat pumps to achieve the purpose of heating in winter, but PTC The efficiency of the heater is less than 1, which greatly increases the power consumption of the vehicle in winter and seriously reduces the cruising range; the working fluid of the heat pump system is R407C or R410A, and these two refrigerants are mixed refrigerants, which are not very environmentally friendly and In winter, the heating efficiency is lower than 2, and the ambient temperature can only work normally above -20 degrees Celsius, which cannot meet the heating needs of cold regions, nor can it meet the environmental protection requirements of European and American countries

It is understood that the industry is studying the technology of supplementing air to increase enthalpy to increase the ambient temperature below -20 degrees Celsius for heating, but the system has a complex structure, requires many valves and requires high control accuracy, and cannot solve the problem of exporting overseas. environmental protection issues; some manufacturers use environmentally friendly working fluid 1234yf to meet the needs of single-cooling systems, but the intellectual property rights of this working fluid have not been fully disclosed, resulting in the cost of the refrigerant thousands of dollars, and the air-conditioning refrigeration charge of the bus is relatively large. Only the cost of refrigerant needs to increase by more than 10,000 yuan; in addition, the problem of heating in winter cannot be effectively solved

Images