If the cooling effect of the air conditioner at home is getting worse and worse, many people's first reaction is to add fluoride to the air conditioner. In fact, this is a wrong understanding. When will the air conditioner be fluoridated? How to add fluoride to air conditioner? How much fluorine does the air conditioner contain? (05 12-6070-0075)

First, the difference between different types of refrigerants.

At present, the commonly used refrigerant models are R4 10a, R 134a, R407C and R22. Let's briefly analyze the difference between the two. (05 12-6070-0075)

R 134a is a single-component refrigerant, and R407C and R4 10a are mixed refrigerants. Wherein R4 10a is a mixture of R32 and R 125, and R407C is a mixture of R32, R 125 and R 134a. The advantage of mixed refrigerant is that synthetic refrigerant can be customized according to specific use requirements by considering various characteristics such as flammability, capacity, exhaust temperature and efficiency.

There are many factors to consider when choosing a refrigerant, because choosing any refrigerant will have a certain impact on the overall operation, reliability, cost and market acceptance of the air conditioning system. Everyone is very interested that new refrigerants have different refrigerant transmission performance due to different heat transfer and pressure drop, which will eventually have a significant impact on system design and system performance. We briefly discuss the differences in performance characteristics between these common refrigerants.

The capacity of R 134a is less than R22, and the pressure is lower than R22. Because of these characteristics, the R 134a air conditioner with the same capacity needs to be equipped with a larger displacement compressor, a larger evaporator, a condenser and pipelines. Finally, the cost of manufacturing and operating a system with the same cooling capacity as R22 will be higher, and the R 134a system will need higher cost.

The capacity of R407C refrigerant R4 10a refrigerant has a higher capacity and pressure than R22, and its working pressure is 50%-60% higher. Because of high pressure and high gas density, not only compressors with smaller displacement can be used, but also pipes and valves with smaller diameters can be used. The use of high-pressure exhaust valve eliminates the hidden danger caused by high condensation pressure in the system. The thick compressor shell enables the system to withstand higher working pressure. Another advantage of making the compressor thicker is that the operating noise of R4 10a is obviously 2-4 decibels lower than that of R22 compressor.

Compared with R22 system, R4 10a refrigerant system has obvious heat transfer advantages-the heat transfer of evaporator is 35% higher and that of condenser is 5% higher. The heat transfer coefficients of R 134a and R407C are lower than R22. Under the same mass flow rate, the pressure drop of R4 10a is small, which makes it possible to use smaller pipes and valves than R22 or other refrigerants. This will reduce the cost of materials for manufacturing R4 10a system, which is more likely and more advantageous in long-term housekeeping computers and multi-line systems. Of course, only by redesigning the system can we give full play to the advantages of R4 10a in heat transfer and pressure drop-for example, we can consider adopting the following optimization technologies, using smaller diameter coils and different fin structures, increasing the length of the circulation loop and reducing the number of refrigeration loops. Finally, we can see that in the redesigned system for R4 10a refrigerant, the cost is lower and the refrigerant charge can be reduced by up to 30%. The reduction of refrigerant charge can not only reduce the cost, but also improve the reliability of the whole system.

In the system with the same refrigeration capacity and condensation temperature, the system energy efficiency ratio (COP) of R4 10a refrigerant can be 6% higher than R22. This is because the loss of compressor in the compression process is lower, the heat transfer between evaporator and condenser is stronger, and the pressure drop of the whole system is smaller. Efficient heat transfer and small pressure drop make it lower in condensation temperature and higher in evaporation temperature under the same working conditions, so that the compressor can obtain a better operating range, lower in power consumption and higher in efficiency ratio. In addition, for the low compression loss characteristic of R4 10a, the large compressor in the small commercial air-conditioning system benefits more than the small household air-conditioning compressor.

Second, the commonly used refrigerant models of household air conditioners are R22 and R4 10a.

R22 is used in fixed-frequency air conditioners, which is a transitional refrigerant because of its destructive effect on the ozone layer.

Characteristics of R22: It is a colorless and almost odorless gas at room temperature, non-flammable, non-explosive and non-corrosive, slightly more toxic than R 12, but it is still a safe refrigerant classified as A 1. Pressurized liquid can be liquefied into colorless and transparent liquid. R22 has high chemical stability and thermal stability, especially in the absence of water, and cannot react with ordinary metals below 200℃. In the presence of water, it only reacts slowly with alkali. But it will crack at high temperature. R22 is a low-temperature refrigerant, which can obtain a refrigeration temperature of -80℃.

R4 10a is used for inverter air conditioning. It is a new type of environmental protection refrigerant, which does not destroy the ozone layer. Its working pressure is about 1.6 times that of ordinary R22 air conditioner, and its refrigeration (heating) efficiency is high, which improves the performance of air conditioner and does not destroy the ozone layer.

Characteristics of R4 10a: The new refrigerant of R4 10a is composed of R32 and R 125 quasi-boiling mixtures, each accounting for 50%, and mainly composed of hydrogen, fluorine and carbon (recorded as hfc), which is stable and non-toxic and has excellent performance. At the same time, because it does not contain chlorine, it will not react with ozone, that is, it will not destroy the ozone layer. In addition, the performance of air conditioners with new refrigerants will be improved to some extent. R4 10A is internationally recognized as the most suitable refrigerant to replace R22, and has been popularized in Europe, America, Japan and other countries. The global substitution trend and prospect of R4 10A in major international markets, and the trend of entering the international market.

3. What are the three types of central air conditioners? What are the advantages and disadvantages?

At present, there are three main systems of central air conditioning, namely refrigerant system, water system and air duct system. Let's take a detailed inventory of the advantages and disadvantages of three types of central air conditioners.

Central air conditioning completely bid farewell to the traditional image of "aristocratic products" and become a functional household equipment that everyone wants to try. Say goodbye to the disadvantages of high price and huge volume, so it has achieved quite rapid development in recent years and has the potential to replace traditional air conditioners. At present, there are three main systems of central air conditioning, namely refrigerant system, water system and air duct system. Let's take a detailed inventory of the advantages and disadvantages of the three types of central air conditioners, so that everyone can choose the most suitable central air conditioner according to their own needs and easily bid farewell to the choice syndrome.