Common auxiliary equipment and functions of refrigeration and refrigeration systems

       1. Oil separator
Using the different densities of oil and refrigerant, when the cross-section of the channel increases suddenly, the flow velocity drops sharply (from 10~25m/s to 0.8~1m/s), the heavier oil droplets fall under the action of gravity; the gas flow direction is changed inside the oil or centrifugal action is used to separate the dense oil droplets; the mixed gas is cooled by using the refrigerant liquid or cooling water pipe, so that the oil vapor entrained in it condenses into larger particles of oil droplets; and the filtration equipment is used to filter. From the appearance structure, it is divided into vertical oil and horizontal oil.
2. Vapor-liquid separator
The function of the vapor-liquid separator is to prevent the liquid droplets in the evaporator that have not evaporated from entering the compressor with the air flow, causing liquid shock. Its structure is similar to that of an oil separator, and it also uses the change in speed to make the gravitational droplets settle down. The low-pressure circulating barrel is also a kind of vapor-liquid separator, which is an important equipment for gravity liquid supply system and pump liquid supply system. During operation, a certain liquid level must be maintained. Systems with different evaporation temperatures should be equipped with separate vapor-liquid separators.
3. Air separator
Another important piece of equipment in the ammonia system is the air separator, which is used to vent non-condensable gases such as air in the system, especially for systems that often operate at low temperatures or sub-atmospheric pressures. For small and medium-sized Freon systems, air separators are usually not added, but are discharged directly from high-pressure equipment such as condensers.
4. a liquid reservoir
The liquid reservoir is used to store the refrigerant liquid condensed by the condenser in the refrigeration system, to regulate the supply and demand relationship of the refrigerant liquid between the condenser and the evaporator, and to prevent the refrigerant gas from the high-pressure system from channeling into the low-pressure system (liquid seal), which is called the high-pressure liquid reservoir.
5. a liquid drain bucket
It is mainly used in gravity liquid supply systems to contain the refrigerant liquid discharged back during hot gas defrosting. Its structure is the same as that of a high-pressure reservoir.
6. Low-pressure circulating barrel
The low-pressure circulating barrel is the key equipment of the pump liquid supply system. Its function is to store and maintain a certain liquid, stable low-pressure refrigerant liquid required by the circulating pump, and at the same time play the role of a vapor-liquid separator, and can be used as a drain tank if necessary. The structure is basically similar to that of a vapor-liquid separator.
7. an oil collector
The oil collector is an important piece of equipment in the ammonia system, which is used to recover and discharge the lubricating oil stored in each equipment in the system. The oil collector is composed of a barrel body, an oil inlet valve, an oil drain valve, a return valve, a grease mirror and a pressure gauge.
8. an oil cooler
The lubricating oil separated from the oil absorbs the heat of friction and the heat of the gas, which increases the temperature (close to the exhaust temperature). The normal service temperature of lubricating oil is 30~60 °C, and the viscosity of the oil is too high to decrease, which will weaken the sealing effect, increase the internal leakage, and reduce the efficiency of the compressor, so the lubricating oil must be cooled before it can be recycled. The oil cooler is the role of cooling the oil.
9. Oil filter
In order to protect the normal operation of the oil pump, the impurities are filtered through the crude oil filter before the lubricating oil enters the oil pump. The filter consists of a housing and a metal strainer, and the housing is equipped with a refueling valve, through which the initial refueling is passed. Refueling can be done by vacuuming the system or by the oil pump. For the first operation of the machine, check the cleanliness of the crude oil filter after the initial operation, and regularly disassemble the filter according to the cleanliness of the system.
10. Suction filter
The suction filter is mainly composed of a shell and a metal filter, etc., and the suction filter is used to eliminate impurities in the medium to protect the normal use of valves and equipment
11. an oil pressure regulating valve
The function of the oil pressure control valve is to regulate the fuel injection pressure of the compressor. If the oil pressure entering the compressor is too high, the amount of fuel injected will be too large, which will not only affect the suction volume of the compressor, but also increase the power consumption of the compressor, and will increase the possibility of oil leakage from the shaft seal;
12. a regulating station
In ammonia refrigeration systems, especially for large and medium-sized cold stores (more than 500t), the refrigeration system usually has multiple evaporation temperatures and multiple liquid supply pipelines. To meet the demands of the refrigeration process, throttle valves are required for each evaporation temperature or supply line to control liquids and gases. The regulating station is actually a valve group that centralizes all the throttle valves for easy operation. The regulating station includes the general liquid regulating station in the computer room and the liquid and gas sub-regulating station in the warehouse.
13. a liquid supply pump
Liquid supply pumps, especially solution pumps, play an important role in ammonia refrigeration systems. Main function: to provide normal circulating flow, ensure the absorption of ammonia in the absorber, and improve the efficiency of the refrigeration system. the efficiency of the refrigeration system.
14. Evaporator pressure regulating valve
Also known as evaporative pressure regulating valves or pressure reducing valves, they are a critical component in a steam system. Its main function is to maintain the stability of the evaporation pressure in all parts of the refrigeration system and to prevent the evaporator pressure (and thus the evaporation temperature) from dropping below the specified value. In some cases, evaporator pressure regulators are also used to adjust the load of the evaporator to accommodate changes in system load.
15. Hydraulic protector
It is used to monitor and protect the pressure of the lubricating oil from damage to the system caused by too low or too high oil pressure.