How to prevent freezing in winter heat pump What should I do if the unit is frozen

How to prevent freezing in winter heat pump What should I do if the unit is frozen

With the promotion and subsidies of the government, before the 2020 heating season, Detroit installed about 100,000 air-energy heat pumps on a large scale to replace traditional coal-fired heating.

　　 1. Do not power off the host at will

　　 When users use air source heat pumps for heating, most of them are at night when the temperature is low, the temperature is high during the day or when they are not at home, they may turn off the host in order to save power. This is actually very dangerous, because the heat generated by the air source heat pump unit is transferred through water as the carrier. If the power is cut off when used in a low temperature environment, the host is likely to be frozen.

　　Electric box separately equipped for common people

　　 The correct method should be to set the set temperature of the unit to the lowest when the main engine is not required to work, so that the unit can ensure the antifreeze function to work, so that the energy waste and antifreeze problems of the unit can be effectively solved.

　　 After a long period of passive power failure, the antifreeze of the pipeline is a problem

　　 In addition, in rural areas, passive power failures are likely to occur, such as power outages at the power supply bureau, or power failures due to circuit problems caused by wind and snow disasters. If you encounter such a situation, the power outage time may be relatively long. At this time, the user must take certain measures to prevent the host from being frozen, and open the union and valve to drain the water in the pipeline. In this way, even if there is a power failure, the pipeline and the host can be prevented from freezing due to low temperature.

　　 2. Don't disturb the control panel function keys

　　 There are many buttons on the control panel of the host, some are for adjusting the water temperature, and some are for timing. If the user disturbs, it may affect the normal operation of the host. For example, if the timer button is pressed, the host may not start when it needs to work.

　　 If the weather is suddenly very cold and the room temperature is not enough, you can adjust the outlet water temperature to 40℃ or above

　　 When installing, the installer will set the water temperature, etc., and tell the user which keys can be moved, and which keys should not be moved randomly. Generally, users only need to adjust the temperature of the outlet water. When the indoor temperature is not enough, adjust the outlet water temperature higher, and lower the water temperature when the indoor temperature is too hot. For example, we generally set the outlet water temperature to 35°C and the room temperature to 18°C. If the weather is suddenly very cold and the room temperature is not enough, the outlet water temperature can be adjusted to 40°C, and vice versa.

Also, when setting the user, it’s best not to set the room temperature high for the sake of "heating", because the temperature is high and the unit will work longer and consume more power. The room temperature is set to 18℃ and 25 ℃, the operating cost may double, so set the appropriate room temperature. For room ventilation, try to ventilate when the outdoor temperature is high during the day.

　　 Three, when the host fails, first look for after-sales

　　 The air source heat pump main unit will inevitably have malfunctions when it is running. At this time, the user should not panic, and cannot move the function keys on the control panel or move the main unit at will. Because this is not only useless, sometimes it can make the fault worse.

　　 The correct approach should be to contact the after-sales personnel (the manufacturer will leave contact information) and tell the other party what the fault code is on the control panel, and then the after-sales personnel will identify the problem based on the fault code. If the problem is relatively simple, such as a water flow fault, the after-sales staff can tell the user how to deal with it on the phone; if the problem is more complicated and it is not clear on the phone, the after-sales staff will come to the door to solve the problem in time.

　　 Fourth, clean up the defrosting water in time

The installation time of the Detroit rural “coal-to-electricity" project is relatively tight, and sometimes the installation is not very standardized. For example, if the drainage pipe after defrosting is not handled properly, it may cause the defrosted water to flow to the ground, which will be very fast when the weather is cold. Icing will not only cause inconvenience to users, but also damage the unit.

　　 Due to the limited installation location of farmers in Detroit, many machines are installed in the yard, and the defrosting water must be treated in time

Because the water after defrosting will accumulate more and more, the ice formed will accumulate and thicker, and it will slowly freeze up along the drain pipe. If it is not handled in time, not only the host will not be able to defrost, but also Will cause devastating damage to the host. Therefore, it is best for users to clean up in time and handle the drainage problem with the assistance of after-sales personnel to eliminate hidden dangers.

　　 5. Do not accumulate debris around the host

Air source heat pump heating is to absorb the heat in the air, and then vaporize through the evaporator, compress it into high-pressure gas by the compressor, and then enter the condenser to liquefy, transfer the absorbed heat to the heated water, and so on, continue to absorb the low temperature source Heat and output the heated water to reach the predetermined temperature directly. If there are debris around the host and the distance is close, it will definitely affect the heat exchange effect. Generally speaking, leave at least 80 cm distance around the host.

　　 Poor ventilation at the installation location will affect the heating effect of the machine, so pay attention to cleaning

　　 It is also important to note that the main engine fan blows out cold air. If there is debris in the front, it will affect the dissipation of the cold air, which will lead to insufficient heat in the air and affect the heat exchange effect. Therefore, it is best that the front of the fan should not have any obstructions within 2 meters. If it is too close, it may send the cold air back to the main unit, and the heating effect will be very low.

　　 There is another problem. In addition, it is necessary to clean the attachments on the evaporator in time. The host will suck some leaves or other debris onto the evaporator during heat exchange. In addition, Beijing is more haze and the air contains more pollutants such as dust, which will also pollute the surface of the evaporator. If it is not cleaned in time , Will affect the heat absorption effect of the evaporator.

　　Frozen unit case analysis

　　Case 1: There is a villa user in Nanjing who is not resident at home. He went abroad for vacation last winter. The electricity was cut off and there was no drainage. As a result, the machine was completely frozen after returning.

　　Analysis: Because it was extremely cold last year, the internal panels of the unit were frozen out after being replaced, and the system was scrapped after being turned on. Do not turn on the machine at this time, first melt the ice, release the water, then cut off the water-side heat exchanger, use the welding torch to weld first, disconnect the heat exchanger system and other systems first, and then blow other systems with nitrogen. Is there any water? If there is water, you must first blow dry or use the sun to make sure that there is no water inside, and then turn on the compressor. If it can turn on, there is no problem. Just replace the heat exchanger. If it is in the heat exchanger system If the compressor is turned on without disconnection, it is likely that water will enter the compressor and the entire system will be scrapped.

　　 Solution: There is also a way to deal with this situation, which is to install an automatic valve, which automatically opens to drain the water when the power is cut off. It is not expensive to install an automatic valve. The better one is only about 200 yuan, but this valve also has a limit, that is, it must be installed at the lowest point of the pipeline. Sometimes it is difficult to find the lowest point, especially when the end is heated.

　　 Case 2: In a rural area in Philadelphia, the machine was frozen in winter, so I called the contractor to repair it.

　　Analysis: The temperature in Philadelphia, especially in the north, is very low in winter, and it is easy to be frozen if the antifreeze is not done well. Water will freeze when the temperature is lower than 0℃, and the volume of water will expand when it freezes, and the expansion coefficient of the pipeline and water are different, so when the water temperature in the pipeline is lower than 0℃, the pipeline may be frozen. The internal antifreeze protection fails when the temperature is lower than 0℃ and the unit is not powered on or the unit is in standby state. There is also a power outage. There are more power outages in northern rural areas. When the ambient temperature is low, more than 2 hours is more dangerous, but the owner will generally not tell you that the power is out.

Solution: In this case, we usually remove the heat exchanger of the machine and send it to the heat exchanger manufacturer for inspection. Look at the shape of the casing and the heat exchanger. If it is frozen, the deformed shape is different. Water is usually caused by power failure, and there will be rust spots inside. The solution steps are the same as in Case 1. The ice must be melted to drain the water first, and then it can be turned on after drying.

　　Case 3: A dual-generation unit in Chicago was frozen during the summer cooling.

　　Analysis: If the temperature probe fails or is inserted in the wrong position during cooling, the machine will also be frozen. Generally, the temperature we set is 12°C, and the outlet temperature is 7°C. If the temperature is not right, the main engine may still keep cooling after the effect is achieved, resulting in icing. Or the water flow is not smooth, the temperature probe to be measured is placed on the pipe. The temperature of the pipe is high, and the board will keep cooling and freeze out, especially if there is a buffer water tank, the temperature sensor is in the water tank. The water in the water tank is not flowing, and the temperature is relatively high. The plate changer will freeze if it keeps cooling, and the plate changer’s antifreeze performance is a bit worse, and it is more likely to freeze.

　　 Solution: In the case of poor water flow, generally we will install a water flow switch to detect the water flow. If the water flow is not smooth, the machine will automatically stop working.

　　What are the common antifreeze measures?

If the set temperature of the water tank is 45℃ or 55℃, when the temperature of the water tank reaches this temperature value, the host will stop working. If the end is not working, the pipe temperature will drop at this time. When the temperature is too low, say 3℃, At this time, the host control panel can automatically start the circulating water pump according to the set temperature value (3°C) to ensure that the pipeline does not freeze due to low temperature.

However, this method has a disadvantage. When the position of the temperature sensor is not good, the accuracy will be problematic. There is also an electronic product like the temperature sensor, which sometimes fails. The measured temperature and If the actual temperature is different, a misjudgment will occur at this time. In addition, this method will not work when the power is off.

　　 There is another kind of antifreeze. In the northern rural areas, there are sometimes power outages, or the entire family goes on vacation. Although there are instructions on the host and there are hints in the manual, users may not care about it, or may not remember it after a year and a half. Generally, before the arrival of winter, agents should remind customers to pay attention to anti-freezing, but sometimes customers will not pay attention. Therefore, we sometimes recommend that customers use antifreeze.

But antifreeze also has its shortcomings: first of all, its specific heat capacity is lower than that of water, less heat under the same volume, less wind blown by the fan or lower temperature of the floor heating, and antifreeze heat dissipation faster , It may also have a certain impact on the heating effect.

　　 This point is not too obvious in actual operation, and the impact is not great. There is also a disadvantage of cost. The more expensive one may cost 6-8 yuan/kg, and the cheaper one costs two or three yuan. Calculated on the basis of an area of ​​150 square meters, add a 100-150L buffer water tank, and add the flow rate in the floor heating pipe, it is about 200 kilograms, and it costs 5 yuan/kg to 1,000 yuan. Some customers may be reluctant .

　　The other thing is to use electric heating cables, which used to be done when solar energy was used in the north. When the ambient temperature is low or the machine stops working, the electric heating cables will be activated, and the power will be cut off automatically when the pipe temperature reaches a certain value. Of course, this method also has the limitation that it cannot be used after a power outage.