Knowledge of refrigerator condenser and evaporator

1. Condenser

1. The role of refrigerator condenser

The refrigerator condenser is one of the heat exchangers in the refrigeration system. Its function is to dissipate the heat of the high-pressure, high-temperature refrigerant gas sent by the compressor to the outer space of the refrigerator. The refrigerant liquid is liquefied after heat dissipation and cooling, and becomes a high-pressure, normal-temperature refrigerant liquid.

2. The shape of refrigerator condenser

According to the way of heat dissipation, it can be divided into two types: natural convection cooling and forced convection cooling. Natural convection cooling uses the surrounding air to naturally flow through the surface of the condenser, so that the heat of the condenser can be dissipated. Forced convection cooling uses an electric fan to force air to flow through the surface of the condenser to dissipate heat from the condenser. Refrigerators above 300L generally use forced convection condensers, and refrigerators below 300L generally use natural convection condensers.

3. The condenser is structured according to the shape

It can be divided into flat plate type, shutter type, steel wire coil type, fin coil type and built-in type. Among them, flat plate, louvered, steel wire coil and built-in condensers are natural convection condensers; finned coil condensers are forced convection condensers.

The heat dissipation area of the flat-plate condenser is relatively small, and the heat transfer coefficient is not very high. It is the structure used in the early stage of the condenser.

2. Evaporator

1. The role of the evaporator

The evaporator and the condenser are also the heat exchangers of the refrigeration system. Its function is to make the low-pressure liquid refrigerant evaporate and absorb heat, so that the temperature in the refrigerator is lowered. In order to achieve this goal, the evaporator has a large pipe diameter and the materials used have good thermal conductivity. In addition, while reducing the temperature in the box, the evaporator will also condense and separate the water vapor in the air in the box and condense into frost, thereby dehumidifying. The lower the surface temperature of the evaporator, the more significant the dehumidification effect.

2. The shape of the evaporator

Most of the evaporator is a gas-liquid mixing zone. When the refrigerant enters the evaporator, its gas content is only about 10%, and the rest is liquid. As the refrigerant flows and absorbs heat in the evaporator, the liquid gradually vaporizes into a gas. When the refrigerant approaches the exit of the evaporator, it becomes completely gas. In this process, the evaporation temperature of the refrigerant is always constant and corresponds to the evaporation pressure.

3. The evaporator is structured according to the shape

The evaporator of a refrigerator can be divided into two types: natural convection and forced convection according to the different ways of air circulation and convection. According to the different shape and structure, it can be divided into tube-plate type, composite plate type, steel wire coil type, fin coil type and single-ridge fin type.