Automotive Air Conditioning Compressor for New Energy Vehicles: The Comfort Center Empowered by Innovation
Overview of the Air Conditioning System for New Energy Vehicles
The air conditioning system of new energy vehicles plays a vital role in the vehicle, as it directly affects the comfort of drivers and passengers. The air conditioning system of new energy vehicles mainly consists of the refrigeration system, heating system, air supply system, control system and air purification system.
The refrigeration system usually consists of electric compressor, condenser, pressure sensor, electronic expansion valve, evaporator and so on. Among them, the electric compressor is the core component of the refrigeration system. The electric compressor sucks in low-temperature and low-pressure gaseous refrigerant, compresses it into high-temperature and high-pressure gas, and then discharges it out of the compressor. The condenser cools the high-temperature and high-pressure superheated refrigerant gas, condenses it into liquid, and releases a large amount of heat. The electronic expansion valve and evaporator are responsible for adjusting the flow and pressure of the refrigerant, so that the refrigerant expands and absorbs heat in the evaporation box, thereby cooling the air blown by the blower.
There are several types of heating systems. One type is heating through a PTC heater. The PTC heater is generally installed under the floor between the driver’s seat and the front passenger seat, and consists of electric heating PTC heater elements, cooling fans, coolant flow paths, control boards and other components. Another type is the heat pump air conditioning system, which is improved on the basis of traditional fuel vehicles. The compressor is directly driven by a permanent magnet DC brushless motor. There is also a parking heater for heating. The fuel is pumped to the metal felt in front of the combustion chamber through a metering oil pump. After the igniter is heated, the splashed tiny oil droplets are vaporized. Air mixes with gasoline and is ignited. The heat energy is transferred to the engine coolant, and then the coolant is circulated by the electric circulation water pump into the radiator in the evaporation box to heat the air inside the vehicle.
The working principle of the air conditioning system of new energy vehicles is similar to that of traditional fuel vehicles to a certain extent, but there are also differences. For example, in terms of refrigeration, both are realized through the compressor and refrigerant. But in terms of heating, traditional fuel vehicles mainly rely on the thermal effect of engine coolant, while new energy vehicles need to generate heat through electric heating elements or heat pump technology.
In short, the composition and working principle of the air conditioning system of new energy vehicles are relatively complex, but they are of great significance for improving the comfort of drivers and passengers and the overall performance of the vehicle.
MinKa Compressor(042400-0233)
Types Of Compressors
(1) Classification by Driving Method
Traditional engine-driven:This type is commonly used in traditional fuel vehicles, and some hybrid electric vehicles among new energy vehicles may also adopt it. It is characterized in that the compressor is driven by the engine drive belt.Advantages: mature technology, relatively simple manufacturing process, low cost.Disadvantages: when the engine stalls, the air conditioning compressor also stops working, which affects the use of the vehicle air conditioner. Moreover, its working efficiency is greatly affected by engine speed.
Hybrid type driven by engine and electric motor:For automakers that need to improve the efficiency of existing internal combustion engines and achieve miniaturization, compressors driven by traditional engine drive belts are provided.For vehicles with the engine as the main power and the electric motor as the auxiliary power (Mild HEV), hybrid compressors supporting both belt drive and electric motor drive are provided.Advantages: the appropriate driving method can be selected according to different working conditions to improve energy efficiency.Disadvantages: relatively complex structure, high cost.
Pure variable frequency electric motor-driven:For vehicles with the electric motor as the main power (strong HEV, EV), electric compressors are provided.It is characterized in that the compressor is directly driven by the electric motor, with high working efficiency and fast response speed. The compressor can automatically adjust the rotating speed according to the vehicle interior temperature demand to achieve accurate temperature control.At the same time, since there are no engine transmission parts, energy loss is reduced, making it more energy-saving and environmentally friendly.
(2) Classified by working principle: Fixed displacement compressors have their discharge volume increase proportionally with the increase in engine speed. The working principle is to control the start and stop of the compressor by collecting temperature signals from the evaporator outlet or the pressure of the air conditioning system. When the temperature reaches the set value or the pressure in the pipeline is too high, the compressor stops working; when the temperature rises or the pressure drops, the compressor restarts. Its advantages are simple structure, mature manufacturing technology, and relatively low price. However, it cannot automatically change the power output according to the cooling demand, has a significant impact on engine fuel consumption, and will frequently start and stop during operation, which affects comfort and the lifespan of the compressor.
Variable displacement compressors: Variable displacement compressors can automatically adjust the power output according to the set temperature. The air conditioning control system does not collect temperature signals from the evaporator outlet, but instead controls the compression ratio of the compressor based on the change signal of the pressure in the air conditioning pipeline to automatically adjust the outlet temperature. During the entire cooling process, the compressor is always in operation. Its advantages are that it can automatically adjust the cooling intensity according to actual needs, improve energy utilization efficiency, and reduce energy consumption. However, its structure is complex, the cost is high, and the requirements for the control system are also higher.
(3) Classification by working mode: Reciprocating compressors: The working process is divided into four stages: compression, exhaust, expansion, and intake. When the crankshaft rotates, it drives the piston to move back and forth through the connecting rod, causing the working volume formed by the inner wall of the cylinder, the cylinder head, and the piston top to undergo periodic changes, thereby playing a role in compressing and transporting refrigerant in the refrigeration system. The advantages are mature manufacturing technology, simple structure, low requirements for processing materials and processing techniques, lower cost, strong adaptability, and strong repairability. The disadvantages are that it cannot achieve high rotational speed, the machine is large and heavy, it is difficult to achieve lightweighting, the exhaust is discontinuous, the airflow is prone to fluctuation, and there is significant vibration during operation. Currently, it is mostly applied in large-displacement air conditioning systems of buses and trucks. Axial piston type: Common types include rocker plate type or inclined plate type compressors, which are the mainstream products in automotive air conditioning compressors. The cylinders are arranged around the center axis of the compressor, and the piston movement direction is parallel to the compressor's main shaft. The inclined plate is fixed together with the compressor's main shaft, and the edge of the inclined plate pushes the piston to perform axial reciprocating motion. The advantages are that it is easy to achieve miniaturization and lightweighting, can achieve high rotational speed operation, has a compact structure, high efficiency, and reliable performance. After achieving variable displacement control, it is widely used in automotive air conditioning.
Rotary compressor :Rotary vane type :The cylinder has circular and elliptical shapes.The main shaft of the rotor has a certain eccentricity or coincidence with the cylinder. The vanes divide the cylinder into several spaces. When the main shaft drives the rotor to rotate, the volume of these spaces changes continuously to realize suction, compression and discharge of refrigerant.Advantages: small size and light weight, easy to arrange in a narrow engine compartment, low noise and vibration, high volumetric efficiency.Disadvantages: high requirements for processing accuracy, high manufacturing cost.
Scroll type:As the fourth-generation compressor, its structural features include a pair of spirally wound fixed scroll and orbiting scroll, brushless motor, etc.The working principle is divided into three processes: suction, compression and discharge.In the suction process, gaseous refrigerant is sucked from the air inlet into the compression chamber, which expands as the orbiting scroll rotates.In the compression process, the volume of the compression chamber gradually decreases, and the gaseous refrigerant is compressed and discharged to the center of the fixed scroll.In the discharge process, when the gaseous refrigerant is compressed to a high pressure, it is discharged from the central discharge port of the fixed scroll by pressing the discharge valve.Advantages: high efficiency, low noise, reliability, energy saving, etc.Disadvantages: relatively complex technology, high cost.
