RU2760881C1 - Refrigeration unit with double throttling - Google Patents

Abstract

FIELD: refrigeration.

SUBSTANCE: invention relates to refrigeration equipment, more specifically, to circuits of refrigeration units, and can be used in manufacture of refrigeration machines. The refrigeration unit with double throttling comprises a compressor, an evaporator, a condenser, an intermediate receiver, and control valves. The refrigerating agent is compressed in the compressor and supplied to the condenser, cooled therein to a saturated state and condensed, and supplied to the linear receiver. The formed liquid refrigerating agent is throttled by means of a control valve into the intermediate receiver, wherein the separated liquid is passed through an electronic heat regulating valve to the evaporator, and the formed vapour is supplied to the suction pipeline of the compressor through an upstream pressure controller.

EFFECT: increase in the amount of liquid contained in the vapour and liquid mixture at the input of the evaporator of the refrigeration unit, and corresponding increase in the coefficient of heat transfer from the refrigerating agent to the surface of the evaporator.

1 cl, 1 dwg

Description

The invention relates to refrigeration equipment, and more precisely to circuits of freon refrigeration units, and can be used in the design and operation of refrigeration systems.

Known one-stage refrigeration unit with throttling of the refrigerant to boiling pressure, containing a compressor, condenser, throttle device and evaporator [1].

The disadvantage of this installation is the large amount of steam in the vapor-liquid mixture, which flows after throttling into the evaporative part of the refrigeration unit, and, as a consequence, a low heat transfer coefficient.

As the closest analogue, a refrigeration unit with throttling of a refrigerant to boiling pressure and subsequent separation of oil and vapors in a hydrocyclone was chosen, containing a compressor, a condenser, a heat exchanger-evaporator, a regenerative heat exchanger and an evaporator [2]. The installation allows to reduce the mass vapor content of the refrigerant at the inlet to the evaporator.

The disadvantage of this installation is the complex hardware design and the impossibility of complete separation of steam from the vapor-liquid mixture in the hydrocyclone, as well as the complexity of the hydrocyclone operation with a variable flow rate through the throttle device.

The technical result of the proposed refrigeration unit is an increase in the amount of liquid contained in the vapor-liquid mixture at the inlet to the evaporator of the refrigeration unit, and, accordingly, an increase in the heat transfer coefficient from the refrigerant to the surface of the evaporator.

The technical result is achieved by the fact that the refrigeration unit includes an intermediate receiver with a pressure regulator in it and an electronic thermostatic valve.

Figure 1 shows a diagram of the proposed installation.

The installation contains a refrigerating machine with compressor 1, condenser 2, linear receiver 3, thermostatic valve 4, intermediate receiver 5, pressure regulator “upstream” in intermediate receiver 6, electronic thermostatic valve 7 and evaporator 8.

The installation works as follows.

The refrigerant is compressed in compressor 1 and enters the condenser 2, where it is cooled to a saturated state and condenses, and enters the linear receiver 3. The formed liquid refrigerant is throttled by means of the control valve 4 into the intermediate receiver 5. In the intermediate receiver, the separated liquid is directed through an electronic thermostatic valve 7 into the evaporator 8, and the formed steam through the pressure regulator "to itself" 6 enters the suction pipe of the compressor 1.

In order to obtain a refrigerant with a lower mass vapor content at the inlet to the evaporating devices of the refrigeration unit, double throttling of the refrigerant after the condenser and simultaneous regulation of the intermediate pressure before the second throttling are provided. Intermediate pressure regulation is achieved by including an intermediate receiver in the refrigeration machine and a pressure regulator "upstream" to maintain the pressure in it above the boiling pressure of the refrigerant by 2-3 atm. The first throttling is carried out into the intermediate receiver 5 by means of a thermostatic valve 4, in which the pressure is maintained by a pressure regulator "upstream" 6. From the intermediate receiver, the refrigerant is throttled into the evaporating system at a pressure difference of more than 2 atm by means of an electronic thermostatic valve 7.

Reducing the mass vapor content at the inlet to the evaporator after throttling is a distinctive feature of this refrigeration unit. The evaporator receives a vapor-liquid mixture with a high content of liquid refrigerant in comparison with the scheme with single throttling, which, accordingly, leads to an increase in the heat transfer coefficient in evaporators with in-line boiling of the refrigerant.

In the proposed refrigeration unit, due to the introduction of an intermediate receiver, a pressure regulator "upstream" and an electronic control valve, a decrease in the vapor content at the inlet to the evaporator is achieved, which favorably affects the distribution of the refrigerant and the heat transfer coefficient from the refrigerant side in the evaporative part of the refrigerant. That allows you to get a more efficient refrigeration unit.

Literature sources

1. Refrigerating machines: a textbook for students. universities, training. by special "Technology and physics of low temperatures" / A.V. Baranenko, N.N. Bukharin, V.I. Pekarev. 2nd ed., Rev. and add. - SPb .: Polytechnic, 2007 .-- 994 p.

2. АС No. 2115069 USSR, F25B 1/00. Refrigeration unit / Oleinik V.V. -No. 9611648 / 06-06; declared 09/19/1996; publ. 10.07.1998.

Claims (1)

Refrigeration plant with double throttling, containing a compressor, an evaporator, a condenser, characterized in that the refrigerant is compressed in the compressor and enters the condenser, where it is cooled to a saturated state and condensed, and enters the linear receiver, the resulting liquid refrigerant is throttled by the control valve in an intermediate receiver, in which the separated liquid is directed through an electronic thermostatic valve to the evaporator, and the formed steam through the pressure regulator "upstream" enters the compressor suction line.

Images