RU2285869C2 - Refrigeration plant with pump-circulation cooling system - Google Patents

Abstract

FIELD: refrigeration or cooling, particularly compression machines, plant or systems with non-reversible cycle.

SUBSTANCE: refrigeration plant comprises two-step compressor, condenser, receiver, regulating valve, economizer, air cooler and mixing chamber. The receiver is provided with coil and may act as liquid separator, circulation, linear and drain receivers to provide dosed coolant supply into cooling system. The first compressor stage cylinders may suck coolant from receiver and feed coolant in mixing chamber. Vapor exiting from economizer is also fed into the mixing chamber. The second stage cylinders suck vapor from mixing chamber and supply vapor to condenser. Liquid coolant from condenser passes into receiver via economizer and coil and then into air cooler through regulation valve. Vapor from air cooler enters receiver.

EFFECT: reduced ammonia consumption, power inputs, costs and increased plant safety.

Description

The invention relates to refrigeration and can be used both in single-stage and in two-stage with economizer refrigeration units with pump-circulation cooling systems.

Known refrigeration unit with a pump-circulation cooling system in which compressors, a liquid separator, a circulation receiver, linear and drainage receivers, as well as intermediate vessels are used [1 Pokrovsky N.K. Chillers and installations. M.: Food Industry, 1969, p.177, Fig. 126.]

The disadvantage of this refrigeration unit is the presence of a large number of capacitive equipment, valves and pipelines, which leads to a significant increase in the ammonia consumption of the system, the area of the compressor shop, the cost of the installation and to increased danger during its operation.

The technical result of the invention is a significant reduction in energy consumption, ammonia system, the cost of the refrigeration unit and increase its safety.

The technical result is achieved by the fact that the refrigeration unit with a pump-circulation cooling system is equipped with a mixing chamber, the receiver has a calculated volume for placement of liquid ammonia, necessary to ensure the operation of the refrigeration unit, a volume for dumping the vapor-liquid mixture during defrosting of cooling devices, a safe steam volume that excludes wet stroke and water hammer in the compressor, equipped with a coil and made with the possibility of providing a metered charge of refrigerant in the cooling system, the compressor filled with the ability to suck the first stage of refrigerant from the receiver by cylinders and supply it to the mixing chamber, into which the vapors are supplied from the economizer, and with the possibility of suction of vapors from the mixing chamber by the second stage cylinders into the condenser, the liquid refrigerant from the condenser enters the receiver through the economizer and the coil, liquid refrigerant is supplied from the receiver through the control valve to the air cooler, steam from the air cooler enters the receiver.

The technical result is also achieved by the fact that in a refrigeration unit with a pump-circulation cooling system, a bypass line with a shut-off solenoid valve is used to defrost the “snow coat” from the surface of the air coolers.

A comparative analysis of the proposed technical solution with the prototype shows that the proposed refrigeration unit with a pump-circulation cooling system differs in combining the functions of a liquid separator, a circulation receiver, a linear and drainage receivers, a coil in one receiver, as well as the use of two-stage compressors with economizers.

The drawing shows a diagram of a refrigeration unit with a pump-circulation cooling system.

The refrigeration unit contains two-stage compressors 1 with economizers 20, a receiver 2, an oil separator 3, a condenser 4, a float valve 5, shut-off solenoid valves 6, 10, 11, 12, 13, 21, electric control valves 7, 22, an air cooler 8, a refrigerating chamber 9, a filling valve 14, a column 15 with a level switch 16, a water pump 17, an ammonia pump 18. a coil 19, a mixing chamber 23, a bypass line 24.

A refrigeration unit with a pump-circulation cooling system operates as follows.

Through a shut-off valve 14, a certain amount of refrigerant is charged into the receiver 2, calculated according to the capacity of the system based on the maximum filling of the receiver 2 in the amount of not more than 70%, thereby receiver 2 acts as a linear receiver.

Two-stage compressors 1 with low-level cylinders suck in refrigerant vapor from the receiver 2 and pump it into the mixing chamber 23, into which cold refrigerant vapor is supplied from the economizer 20.

From the mixing chamber 23, the cooled vapors are sucked up by high-level cylinders and pumped through the oil separator 3 into the condenser 4, where the vapors are condensed into the liquid by irrigation of the heat exchanger with the water supplied by the pump 17. Then, the liquid refrigerant passing through the float valve enters the coils for cooling economizers 20, then into the coil 19 and through the solenoid valve 21, the control valve 22 enters the receiver 2 to constantly maintain the liquid level in it.

The ammonia pump 18 draws liquid refrigerant from the receiver 2 and delivers it through the open valve 6 and the control valve 7 to the air cooler 8 of the chamber 9. In this case, the receiver 2 acts as a liquid separator and a circulation receiver.

Taking heat from the product in the chamber 9, the liquid refrigerant boils in the air cooler 8, the steam formed, passing through the solenoid valve 10, enters the receiver 2. There is a cooling process.

When removing the "snow coat" from the surface of the cooling devices, the refrigeration unit operates in the normal mode, and receiver 2 functions as a drainage receiver. During defrost, the solenoid valves 6, 10 are closed, and the valves 11, 12 open. Hot vapors passing through valve 12 enter the heat exchanger of air cooler 8 and heat its surface, while they themselves condense into liquid, which, passing through valve 11 and float valve 5, enters receiver 2.

To remove oil from the heat exchanger, the air cooler 8 by creating a flow rate in it periodically according to the program briefly opens the solenoid valve 13 on the bypass line 24 and the vapor with the liquid enters the receiver 2.

At the end of the defrosting process of the air cooler 8, the solenoid valves 11, 12 are closed, and the valves 10, 6 open. Cooling in progress.

To monitor the level of refrigerant in receiver 2, column 15 with a level 16 switch is used.

When the receiver 2 is filled to 70%, two duplicated level 16 relays stop the refrigeration unit while simultaneously turning on the light and sound alarms.

The process of production and consumption of cold is carried out automatically.

This technical solution will significantly reduce the ammonia capacity of the system, capacitive equipment, the number of valves, pipelines and improve the safety of the refrigeration unit.

The economic effect of using the proposed refrigeration unit with a pump-circulation cooling system is formed due to a significant reduction in the ammonia consumption of the cooling system, energy consumption, installation cost and increasing its safety.

Claims (2)

1. Refrigeration unit with a pump-circulation cooling system, including a two-stage compressor, condenser, receiver, control valve, economizer and air cooler, characterized in that the installation is equipped with a mixing chamber, the receiver is equipped with a coil and is designed to perform the functions of a liquid separator, circulating, linear and drainage receivers and providing a metered charge of refrigerant into the cooling system, the compressor is capable of suction of cylinders of the first stage of chlorine adagent from the receiver and its supply to the mixing chamber, into which the vapors from the economizer are supplied, and with the possibility of suction of vapors from the mixing chamber by the second stage cylinders into the condenser, the liquid refrigerant from the condenser enters the receiver through the economizer and the coil, and the liquid refrigerant is supplied from the receiver through the control valve into the air cooler, steam from the air cooler enters the receiver. 2. The refrigeration unit according to claim 1, characterized in that for defrosting the "snow coat" from the surface of the air coolers, a bypass line with a shut-off solenoid valve is used.