In refrigeration systems, compressors, condensers, expansion valves (throttle valves), and evaporators are the four major mechanical components in a refrigeration system.
1. The compressor compressor is the main equipment of the refrigeration system. Its function is to absorb the low-pressure low-temperature refrigerant vapor in the evaporator, compress it into high-temperature and high-pressure superheated steam, and promote the circulation of the refrigerant in the system to achieve the purpose of refrigeration. .
The basic working principle is divided into two categories: volume type and speed type.
Volumetric compressors can be divided into two categories, one is a reciprocating compressor, and the other is a rotary compressor.
2. Condenser The condenser is one of the main equipments in the refrigeration system of a vapor compressor. The function is to condense the high-temperature refrigerant vapor discharged from the compressor into a saturated liquid of condensing pressure. In the condenser, the refrigerant vapor transfers heat to a surrounding medium, such as water or air, so the condenser is actually a heat exchange device.
The heat released by the refrigerant in the condenser includes three parts: the heat absorbed by the liquid refrigerant in the evaporator when boiling; the energy converted by the mechanical work consumed by the refrigerant vapor compressed in the compressor; the refrigerant vapor from the evaporator The amount of heat absorbed from the surrounding medium as it flows through the low pressure line (return pipe) of the compressor.
3. Expansion valve expansion valve, also known as throttle valve, functions to reduce the pressure of the high-pressure refrigerant liquid from the condenser and regulate the flow rate, so that the pressure of the refrigerant liquid with the condensing pressure is reduced to the required evaporation pressure. At the same time of depressurization, the refrigerant liquid absorbs heat due to boiling evaporation, lowers its own temperature to the required low temperature, and then delivers the low-pressure low-temperature refrigerant liquid to the evaporator at the required flow rate.
v The expansion valve has many forms, but the basic principle is to force the high-pressure liquid refrigerant to generate a pressure drop through a small hole that adapts to the flow of the system, to vaporize a part of the liquid into a vapor, and to inhale the latent heat of vaporization from itself. The expanded gasified mixed fluid becomes a low pressure and low temperature state.
4. Evaporator The function of the evaporator is to transfer the heat of the cooled medium to the refrigerant through heat exchange.
v (1) An evaporator for cooling a brine such as brine or water, such as a vertical evaporator, a horizontal evaporator, a spiral tube evaporator, or the like.
v (2) Evaporators for cooling air, such as natural convection cooling pipes installed in cold storage, forced cooling fans for cooling air, etc.
v (3) Freeze device evaporators, such as contact cooling plate freezers.
V. Auxiliary equipment of the chiller In the refrigeration cycle system, the refrigerant must undergo continuous circulation of gaseous and liquid, and undergo changes in physical parameters such as pressure, velocity, density and temperature. Therefore, some refrigerant will appear in the system. Some refrigerant oil, such as the refrigerant gas discharged from the compressor, will infiltrate some problems in the system. In order to improve the working conditions of the refrigeration system, some components are usually added to the system, collectively referred to as ancillary equipment. The associated components generally vary with the requirements of the refrigeration system. For example, a refrigeration system that requires a high degree of automation will have an increase in its associated equipment.
6. The intermediate cooler is in the form of a vertical steel shell with a coil. The upper and lower ends are welded by a sealing head. The cooler is covered with a heat insulating layer. At the upper end of the cooler, the tube is extended from the sealing head into the cooler. Extend to 150 to 200 (four) below the normal ammonia level. Its role is to ensure that the low pressure exhaust can be fully washed and cooled. The bottom of the inlet is open and welded with a bottom plate. The purpose is to prevent the incoming gas from directly impacting the bottom of the cooler and flushing the lubricating oil. Two porous umbrella-shaped baffles are provided on the upper part of the cooler to separate the droplets in the ammonia vapor. A pressure balance hole is opened in the pipe wall above the liquid level of the intake pipe to prevent ammonia from entering the ammonia gas pipe during shutdown. The lower part of the cooler is provided with a set of coils for the purpose of making the ammonia liquid too cold. The cooler is also equipped with observation and safety features such as level indicators, pressure gauges and safety valves. The intercooler works as follows: the ammonia gas enters the liquid surface from the straight pipe, is rapidly cooled by the washing of the ammonia liquid, and the ammonia gas is sent to the high pressure stage, and the ammonia gas with the droplets rises during the ascending process. The droplets in the vapor are separated as they pass through the perforated umbrella baffle in the upper portion of the cooler during the ascent. At the same time, the ammonia liquid absorbs the heat of the low-pressure exhaust gas and evaporates.
7. Water Cooling Device In the cooling device of the refrigeration equipment, the circulating cooling water system is often used to cool the refrigeration system to ensure that the condensation temperature of the refrigeration system does not exceed the allowable working conditions of the compressor. In circulating cooling water systems, there are many cooling devices used to reduce the temperature of circulating water, such as general-purpose equipment such as natural draft cooling towers and mechanical ventilation cooling towers.