Characteristics and application analysis of cold storage evaporator

Characteristics and application analysis of cold storage evaporator

As one of the four major components of refrigeration, the evaporator plays a vital role in the entire refrigeration system. Therefore, the compressor and evaporator can only be matched reasonably to make the entire refrigeration system perform better. Therefore, the choice of evaporator It is very important to be allocated to the entire refrigeration system.

　　The two most common evaporators in low-temperature refrigerators are air coolers and platoons. Actual air coolers and platoons have their own advantages and disadvantages:

　　1, enclosure structure

Regardless of whether the cold storage adopts civil construction or steel structure, the load-bearing capacity of the top must be considered, which is called suspended load in the design. When seamless steel pipes are used to make pipes, the design suspension load reference value is 70～80Kg/㎡; if aluminum alloy is used When making the top row of pipes, the design suspension load reference value is 40～50Kg/㎡; if the air cooler is used, only the hanging load of the air cooler needs to be considered locally.

　　2, refrigerant charge

The air cooler occupies a small area and the internal volume is relatively small, so the fluorine capacity of the air cooler occupies a small proportion in the entire refrigeration system; the pipe diameter of the exhaust pipe generally ranges from Φ22 to Φ38, and the more the pipe diameter is The larger the fluorine capacity of the entire refrigeration system increases.

　　The pipe library generally has 2 to 4 times more freon than the fan library. In the future, the price of freon continues to rise and the form of freon replacement, the cost of freon is also a part that can not be ignored.

　　3, defrost method

At present, the common defrosting methods of cold storage air coolers are: natural defrost, water frost, electric defrost and hot fluorine defrost. The automatic defrost of the air cooler is relatively easy to achieve, and the defrosted water flows to the defrost downpipe of the air cooler. Outside the cold storage. Aluminum alloy pipes are mostly used for hot fluorine defrosting, but the pipes are distributed in the warehouse and the water droplets will fall when defrosting. Therefore, when defrosting, the goods should generally be transferred or covered with waterproof plastic cloth. The air cooler is so flexible and convenient to defrost.

　　4, later power consumption

Under the same other conditions, the forced convection of the air cooler relies on the motor to drive the fan and the air cooler defrosts 1 to 2 times a day to produce a certain amount of power consumption; for the exhaust pipe, the exhaust pipe belongs to natural convection, and the general exhaust pipe In addition to about 2 frosts a year, compared with the later power consumption, the aluminum tube is relatively cheaper than the air cooler.

　　 5. Cold storage capacity

The air cooler belongs to forced convection and the cooling speed is fast; the aluminum tube belongs to natural convection, and the cooling speed is relatively slow. Therefore, in the actual cold storage operation, if the main refrigeration equipment is basically the same, the air cooler library and the tube library, and the compressor startup time Similar.

The cold storage capacity of aluminum platoon pipes does not play a big role in the maintenance of the overall storage temperature. The key to the maintenance of the storage temperature is the storage enclosure structure and insulation practices, as well as the cold storage capacity of the stored goods. , The low-temperature cold storage with integral polyurethane foam spraying inside the civil construction frame will save much more electricity than the assembled cold storage structure with single-layer, steel structure, and polyurethane sandwich double-sided color steel plate;

　　 6, dry goods consumption

　　The main factors affecting the dry consumption of goods are: heat transfer temperature difference, wind speed, evaporator working time and packaging method.

Generally speaking, the dry consumption of the goods stored in the cold storage using the air cooler is greater than that of the cold storage using the pipe. However, it should be noted that the main body of the dry consumption refers to the goods rather than the cold storage or the evaporator. So which evaporator to use z* Reasonable, the key issue is what kind of goods are stored and how they are packed. Goods sealed in plastic bags do not need to consider dry consumption.

　　7, efficiency and quality stability

The air cooler is a stereotyped and mature product. It is assembled by professional skilled workers and assembly lines in the factory, and the pipe is assembled on site. The assembly level of the worker has a great influence on the uniformity of the liquid supply of the pipe, and the uniformity of the liquid supply of the air cooler is relatively relatively high. it is good.

The failure point of the air cooler is mainly the motor and electrical components as the running parts. The use of word-of-mouth brand products to prevent the failure rate from being greatly reduced; and the pipe, especially the aluminum alloy pipe, because the welding process requires high, the rigidity is relatively poor, so If the welding is not good, or the force is uneven during hoisting, the probability of leakage of the pipe is very high. As the safety of the refrigeration system is paid more and more attention, the quality control of the equipment will become more and more standardized, and standardized production and management will become an insurmountable threshold for piping.