Why is the application of frequency conversion technology slow in freezing and refrigeration
In household air conditioners, inverter technology has become popular. Compared with household air conditioners, the use of frequency conversion technology in refrigeration and refrigeration systems is of greater significance, because cold storage, especially in the freezing process, is a variable temperature evaporation system. Through frequency conversion speed regulation, the performance of the refrigeration compressor can be greatly improved and significant energy savings.
However, frequency conversion technology has not been widely used in cold storage because of the wrong direction of thinking.
First of all, the evaporation temperature of the air-conditioning system is basically constant. When the load of the air-conditioning room becomes smaller, energy saving can be achieved by reducing the speed of the compressor through frequency conversion technology. The freezing process of a cold storage is a variable evaporation temperature system, such as a meat freezing room. The temperature of the goods in the warehouse is 39℃, and the temperature of the goods out of the warehouse is -15℃. The evaporation temperature will gradually decrease with the change of the temperature of the goods, and cause the refrigeration compressor The cooling capacity and shaft power also gradually decrease, and the coefficient of refrigeration decreases. In this case, reducing the speed of the compressor according to the idea of air conditioner frequency conversion can only further reduce the refrigeration coefficient, and cannot achieve the purpose of energy saving.
Secondly, the frequency conversion technology is a systematic project. Only when the compressor, terminal equipment, and refrigerant transmission system are synchronized frequency conversion will have more significant energy-saving benefits. There is obviously a big gap between cold storage and air conditioning system in terms of automatic control.
Third, the lack of relevant control strategies and operation and maintenance experience may be the bottleneck restricting the application of frequency conversion technology in domestic cold storage.
Fourth, for freezing and refrigeration systems, the application of frequency conversion technology will bring about many corresponding problems, such as the amount of oil returned (because of the low pressure difference) and other effects.
Fifth, the frequency conversion technology has more obvious energy-saving benefits in the quick-freezing warehouse. For the fresh-keeping warehouse, the multi-head parallel technology can completely achieve the energy-saving purpose.
For the variable evaporating temperature system in the freezing room, the opposite idea to the frequency conversion of the air conditioning system can be adopted. The load in the front stage of the cooling process is large, and the compressor speed is reduced through frequency conversion to ensure that the motor is not overloaded; The compressor speed improves the refrigeration coefficient.
In terms of frequency conversion technology application, the refrigeration and refrigeration industry lags far behind the air conditioning industry. Frequency conversion in the freezing process is a good breakthrough. As long as the ideas are correct and the measures are appropriate, I believe that frequency conversion technology will develop rapidly.
