What Are the Different Types of Refrigeration Tools?

An energy-saving hot water system for a ship refrigeration device belongs to the technical field of refrigeration and ship engineering, including condensers, expansion water tanks, hot water shut-off valves, check valves, thermometers, flow meters, programmable controllers, make-up valves, circulating water pumps, and return Water shutoff valve, seawater cooling circuit, three-way valve, float valve, hot water tank. The working principle of the marine refrigeration system is that when the low-pressure refrigerant flows through the evaporator, it absorbs heat from the cold storage to reduce the temperature of the storage, and the refrigerant itself vaporizes into steam, which can become superheated steam at the evaporator outlet. In order to make the evaporator The medium pressure can keep a low value, and can recycle the refrigerant for recycling.

Vapor compression refrigeration is the most widely used mechanical refrigeration today, and it is also the main refrigeration method used by ships. The vapor compression refrigeration system consists of a compressor, a condenser, an expansion valve, and an evaporator, which are connected into a closed system by pipes. The refrigerant circulates in the refrigeration system and exchanges energy with the outside world to achieve refrigeration. Actual refrigeration unit, except

The working principle of the marine refrigeration system is that when the low-pressure refrigerant flows through the evaporator, it absorbs heat from the cold storage to reduce the temperature of the storage, and the refrigerant itself vaporizes into steam, which can become superheated steam at the evaporator outlet. In order to make the evaporator The medium pressure can keep a low value, and can recycle the refrigerant for recycling. The compressor continuously extracts the generated vapor from the evaporator, compresses it, and discharges it under high pressure. The compressed high-temperature and high-pressure superheated steam is pressed into the condenser. Here, cooling the superheated vapor of the refrigerant to the saturation temperature is called the condensation temperature at this time, and the refrigerant liquid condensed into a high-pressure liquid condenser may have a certain degree of subcooling. The expansion valve is used to throttle the high-pressure liquid, and the low-pressure and low-temperature wet steam after the throttle is entered

Refrigerant is a working medium in a refrigeration device, also known as a refrigerant. The refrigerant circulates in the refrigeration system and exchanges energy with the outside world to achieve refrigeration. For marine refrigeration equipment, the safety of the refrigerant is often the first factor to consider. At the same time, general marine refrigeration equipment mostly belongs to single-stage compression, medium and high temperature refrigeration, and mostly lies in the range of medium and small refrigeration capacity. R22 is a refrigerant widely used in marine refrigeration installations, especially certain fluorocarbons are banned. Today, before a new refrigerant more suitable for marine refrigeration installations has been identified, it has become a major transition refrigerant. . ^[1]

Ship food cold storage is usually located near the kitchen and as far away from the engine room and boiler room as possible to reduce the penetration of hot walls. Considering that different types of food have their own different optimal refrigerated temperatures and optimal air relative humidity, and some fishy foods must be separated from other foods, the storage of different foods in separate warehouses generally has greater endurance. Most of the large and medium-sized sea vessels are divided into five reservoirs such as fish, meat, vegetables, food, and beverages. Even on sea vessels with small endurance, at least the high-temperature reservoir temperature should be higher than 0 ° C and the low-temperature reservoir temperature should be low. At 0 ° C. Generally, there is a corridor between the main storage door of the food cold storage and each branch storage door, which is called a buffer room. Some buffer rooms have larger volumes and are equipped with cooling coils. This Suichong Room can also be used as a dry warehouse.

Adjustment of evaporation temperature

For refrigeration equipment with natural convection air in the storehouse, the temperature difference between the evaporation temperature and the storehouse temperature is generally 10-15 ° C. Refrigeration equipment with a pump forcing water or brine to flow, the temperature difference is generally 5-10 ° C. The adjustment of the evaporation temperature is achieved by adjusting the opening degree of the expansion valve. As the opening degree increases, the refrigerant flow rate increases, and the evaporation pressure and evaporation temperature increase, and vice versa, the evaporation temperature decreases. Therefore, during the operation, the opening degree of the expansion valve can be judged according to the change of the suction pressure of the compressor.

Adjustment of condensing temperature

In general, the water-cooled condensation temperature is 5-9 ° C higher than the inlet temperature. The specified condensing temperature is that the R22 refrigeration unit should be below 40 ° C. Therefore, when water is used as the cooling medium, the normal condensation pressure is generally

The degree of automation of modern ships is getting higher and higher, and the role of ship food cold storage as one of the survival conditions of ships has been increasingly recognized and valued. Most of the marine cold storage refrigeration systems use a "one machine with multiple storages" system, that is, during normal work, a refrigeration compressor serves several cold storages at the same time, and the temperature of each storage is different. The difference is very large, and the corresponding evaporation temperature settings are very different. Therefore, the setting of temperature and pressure is very important. ^[1]