Why does the use of cold and air conditioning in a car increase fuel consumption because the car cannot carry a compressor? Automotive air conditioning system _ compressor power is not high
Knowledge point: The principle of the "refrigeration system" of automobile air conditioners is the same as that of domestic air conditioners. Both use compressors to drive refrigerants to achieve cooling by the principle of "evaporation and heat absorption".
Many people think that the power of the air conditioner will be very high, because the internal and external units of the home air conditioner have a huge volume, and it seems to be a very powerful machine. However, these large-scale housings are mainly designed for aesthetics, followed by seemingly large but low-power blowers (fans) occupying a lot of space. The core compressor is actually not large, and the power is often only so-called "a few horses". The space inside the car is very small and does not require a fan of a large size and power, so the volume of the system is not very exaggerated, and the compressor power is actually only "a few horses". _ Concept analysis
Pferdestarke (German) _ metric/metric horsepower unit, abbreviated as PS_ hp is a transliteration. The general unit of measurement in China is "metric horsepower", so there will always be "horse" to call it. The concept is that 1 horsepower can complete 75 kg per meter of work in 1 second. The popular explanation is that it can drive a 75 kg object to move at a speed of "one meter and one second". Therefore, horsepower is a large base energy unit, and 1PS can generate a strong driving force.
The power of the automobile air-conditioning compressor is generally about 3kw, and the power conversion to horsepower only needs "×1.36". In other words, the horsepower of the compressor is generally around 4PS, which will not affect the normal driving level for the car. Because even the most common "1.0L-L3" inline three-cylinder engine, its peak power can reach about 60kw; when driving in the middle and low speed range, the engine's output power is generally the peak [~], about 15 ~20kw-Can I still drive the compressor? Compressor & fuel consumption
The use of automotive air conditioning and refrigeration systems will increase fuel consumption, why? 1: Reason for idle speed! The idling speed of the car when the air conditioning system is not used is about 800rpm, and the output power at this time is as low as 8~10kw. The power standard can only meet the engine's non-stop (self-running). If the power is consumed by about 3kw, the thermal energy generated by the combustion will not be enough to drive the piston crankshaft to self-run. Generally speaking, the engine will stop.
Therefore, after turning on the compressor through the "A/C switch", the ECU driving computer will actively increase the speed to the 1100/1200rpm speed range, on the premise of increasing the speed (intake and fuel injection) to produce about 3kw of power- —Ensure that 8/10kw power meets the self-operation, and the increased power of about 3kw meets the compressor consumption, and high speed is equal to high fuel consumption.
2: Reasons for driving! ——The power is getting worse! Different from the above, the ECU will actively increase the speed at idle to stabilize the flame, but the medium speed driving while driving has met the requirements of "high speed and high power _ no flame", then the ECU will not be driving Increase the speed based on the speed. Then, in the engine speed range where the engine output power is only "~", the power is occupied by the compressor about 3kw, which will obviously lower the performance.
The acceleration of the car becomes "meat" will affect the driving quality, and the smaller the displacement, the worse the power of the car will be more obvious; at this time, the driver will unconsciously increase the throttle driving, and the actual throttle control is the engine throttle. The deeper the accelerator pedal is, the greater the air intake amount and the fuel injection amount (fuel consumption) will increase immediately.
In summary: mass-produced cars do not have the "unable to move" air-conditioning compressors, and some micro-card micro-faces that are not equipped with cold air-conditioning systems are just to reduce manufacturing costs. As for the refrigeration principle, it is also very simple. The "tetrafluoroethane" in the drive line of the compressor is a substance that evaporates to a gaseous state at minus 26 degrees Celsius; the tetrafluoroethane is pushed by the compressor to the radiator for cooling , When it reaches the drying tank, it will be dehydrated, and it will become a lower temperature liquid through the pressure adjustment at the position of the expansion valve. Eventually, it boils and absorbs the heat of the evaporator in the evaporator whose temperature is higher than zero. The blower blows the hot air through the low-temperature evaporator to cool down and becomes the cold air sent into the car. This is also the principle of home air conditioning for reference.
Figure 1: Structural features of the engine and compressor and refrigeration system.
Figure 2: The dynamic principle of the refrigeration system.
Knowledge point: The air-conditioning heating system does not increase power consumption, because the water heating system is used!
The principle is that the internal combustion engine will inevitably generate high temperatures during operation, and the antifreeze coolant will be heated to the range of 90/120 degrees Celsius during the flow of the constant temperature of the body; the warm air system leads the high temperature antifreeze coolant out of a pipeline and adds a group Heater small water tank.
The flow of high-temperature liquid will heat the water tank. At this time, the blower blows cold air through the high-temperature water tank to heat it, and the warm air is sent into the car. Only the blower of the whole system has power consumption, but its power is only about 50 watts (w), and the original generator of the car has a rated power standard of 1200/1500w (1.2/1.5kw), and the redundant and sufficient power generation can be ignored The power consumption of the blower and the oil consumption behind are for reference.
