[Truck House Draft] Nowadays, parking air conditioners are more and more recognized by card friends, but the high cost of modification and the common shortcomings of parking air conditioners make many people discouraged. This article will continue with the last article, "Air conditioning the cab, the truck driver is a professional! ",from the principle of parking air conditioning, modification methods, modification costs, optimization measures, etc.
The parallel parking air conditioner is actually a self-modified form of the original parking air conditioner of the high-equipped model, which is basically similar in form and exactly the same in principle, so card friends don’t have to worry about the problem that the service life of this form of modification is not as good as other modified forms.
Here, let me talk about the principle of automobile air conditioning. In fact, it means that the refrigerant circulates in the air conditioning system, and the evaporator of the refrigerant in the cab changes from liquid to gas, which reduces the temperature in the cab. In the condenser, it is cooled by high-temperature and high-pressure gas and converted into liquid state, thus taking heat out of the cab to the outside of the cab.
The core of automobile air conditioning is the compressor, which plays a role in promoting the whole refrigerant cycle. Therefore, the most important parts of the whole air conditioning system are the evaporator inside the cab, the condenser outside the cab and the compressor. In fact, the air conditioning system is a relatively independent system. As long as the refrigerant circulation is promoted, the air conditioning system can operate normally.
Parallel parking air conditioning is to connect an electric compressor and an air conditioning compressor in parallel to the air conditioning system, so that the refrigerant can be circulated by the air conditioning compressor when it is running, or by the electric compressor when the engine stops running.
The principle is very simple. The next step is to buy accessories and modify the air conditioning system. What is needed is a 24V electric compressor, two three-way valves, two one-way valves, and several air conditioning pipelines …
The first step is to find a suitable position to fix the electric compressor. It is best to be near the frame (that is, the girder) of the automobile compressor. It is suggested to burn a simple bracket with steel plate, fix the bracket on the frame with bolts, and cushion the rubber in the middle for shock absorption. It must not be directly welded to the frame, which will have an impact on the frame.
Then the electric compressor is fixed on the frame by bolts, and a little rubber is also padded in the middle, which can not only reduce vibration, but also prolong the service life of the electric compressor. Note that the installation space must be large enough, otherwise the cab may be perforated and the air conditioning system may be damaged due to vibration and friction at the bottom of the cab when the car is running.
Step 2, discharge the refrigerant. Clean the refrigerant with a refrigerant filling instrument, cut the high-pressure pipe near the automobile air-conditioning compressor at about 30-50 cm, and cut the low-pressure pipe near the air-conditioning compressor at 30-50 cm.
Step 3, parallel pipelines. Connect the cut low-pressure pipeline, the low-pressure pipeline of automobile compressor and the low-pressure pipeline of electric compressor with a tee, and the joint must be tied tightly, then arrange the pipeline and bind it on the frame. A one-way valve is connected to the high-pressure pipeline of the automobile air-conditioning compressor, so that the refrigerant can only flow out from the high-pressure end of the automobile air-conditioning compressor and cannot flow backwards.
Similarly, the high-pressure end of the electric compressor is also connected with a one-way valve. Similarly, only the refrigerant can flow out from the high-pressure end of the electric air-conditioning compressor, and it cannot flow backwards. Be sure to see the direction of the one-way valve clearly when installing, otherwise it will damage the air conditioning system when using it later.
Finally, a tee is used to connect the high-pressure pipe from the compressor with the high-pressure pipe from the electric compressor and the high-pressure pipe to the condenser. At this point, the connection on the refrigeration pipeline is finished. Finally, wrap the pipeline, check whether there is interference in the pipeline and so on.
Step 4, install the condenser fan. For most of them, the air-conditioning condenser is usually in front of the water tank, and the heat dissipation of the air-conditioning condenser depends on the fan of the engine. However, when the parking air conditioner is used, the engine is not running, so an electronic fan must be installed. Some or some models have an electronic fan integrated on the condenser, and this step can be omitted. Just find out the power cord of the electronic fan. At present, there are electronic fans supporting the condensers of various models on the Internet. Generally, the condensers can be installed at a distance of 7CM from the mask.
The fifth step is the connection of electrical wiring. At present, the electric air-conditioning compressors purchased online are generally full frequency conversion. In addition to the electric air-conditioning compressors, they are also equipped with frequency conversion modules, control modules, etc. The wiring is generally complicated, and everyone only needs to wire them according to the schematic diagram.
I won’t talk about the control and the wiring of the frequency conversion module. Every product is different. The main point here is that the power cord of the electric compressor must be thicker, because this power is relatively large, and a conductor with a larger cross-sectional area is needed.
For the motor of evaporator and condenser, we must find the power cord, which is the key to determine the normal operation of evaporator and condenser. The better the heat dissipation of condenser, the better the cooling effect of refrigerant and the cooler the cab.
As for the modification cost, I showed it to the card friends online. If I buy a package, the price is basically around 2700, including an integrated inverter compressor, tee, tee with two check valves, condenser fan, controller and some accessories.
Here, I suggest that you buy it separately. The integrated inverter compressor is about 1600-1800 yuan, the condenser fan is generally within 150 yuan, the tee joint and the tee joint with two one-way valves and other pipeline fittings are 200 yuan, and the parking intelligent air conditioner controller is about within 150 yuan, plus the modification fee of the air conditioner master 300 yuan. The total modification is about 2500 yuan.
After the parking air conditioner is installed, we need to calculate how long a group of batteries can support the parking air conditioner.
For example, let’s take an air conditioning system with an electric compressor with an input power of 800 watts and a refrigeration capacity of about 2,000 watts as an example. In addition, there are two condensing fans with an input power of 120 watts each and an evaporator motor of 80 watts, that is, the total power reaches 1,120 watts. We calculate it as 1,100 watts. A set of batteries in 24V220A stores 5280W*H, and deep discharge of batteries is strictly prohibited, which will accelerate the aging of batteries. Generally, we can only use 70% of the power, that is, 3696W*H at most. 3696W*H divided by 1100W is about 3 hours. Because of the frequency conversion technology adopted by electric compressor, it can be used for about 4 hours.
The biggest disadvantage of parking air conditioner is that it can’t be used for a long time. In order to solve the power problem, I have two schemes.
The first plan is to add a set of batteries. The two batteries of 220A are almost 3,000 yuan, which is a bit expensive, and most people can’t afford it. Moreover, a battery bracket should be fixed on the frame. I don’t really recommend this plan.
The second option is to buy a 24V gasoline or diesel generator, and the price is about 1200 yuan. After installing the low-voltage control circuit, the generator can automatically start when the battery is low and charge the battery. When the battery is full, the generator will automatically stop, which not only avoids the deep discharge of the battery and damages the battery, but also avoids the long-term operation of the generator and the noise disturbing the people.
The author believes that the perfect modification method of parking air conditioner at present is what the appeal said. By connecting the electric air conditioner compressor in parallel with the original air conditioning system, supplemented by the automatic start-stop generator, the dream of blowing the air conditioner as long as you want can be achieved at low cost. (Text/Truck House Contributor: Cars come and go)
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