CN215113321U

CN215113321U - Environment-friendly cascade refrigerating unit

Info

Publication number: CN215113321U
Application number: CN202121516226.9U
Authority: CN
Inventors: 黄新兆; 李尚武; 刘建
Original assignee: Hunan Zhiren Refrigeration Equipment Co ltd
Current assignee: Hunan Zhiren Refrigeration Equipment Co ltd
Priority date: 2021-07-05
Filing date: 2021-07-05
Publication date: 2021-12-10
Anticipated expiration: 2031-07-05

Abstract

The utility model relates to a refrigeration plant technical field provides an environment-friendly overlapping formula refrigerating unit, include: a load-bearing platform; a heat exchanger having a first inlet, a first outlet, a second inlet, and a second outlet; the high-temperature-stage refrigeration cycle system uses a refrigerant R134A, and comprises a first screw compressor, an evaporative condenser and a first liquid storage device; and the low-temperature stage refrigeration cycle system uses a refrigerant R410A and comprises a second liquid storage device, an expansion valve, an evaporator and a second screw compressor. The utility model provides a pair of environment-friendly cascade refrigeration unit need not use the large-scale screw compressor of great displacement, can realize low temperature level single-stage operation to the compression ratio of unit is less.

Description

Environment-friendly cascade refrigerating unit

Technical Field

The utility model relates to a refrigeration plant technical field, concretely relates to environment-friendly overlapping formula refrigerating unit.

Background

The cascade refrigerating unit is widely applied and developed in the low-temperature industrial fields of meat food, medicine production, oil gas recovery and the like. In the cascade refrigeration units in these fields, a screw compressor is generally a screw compressor, and R22 is generally used as a refrigerant.

Although the technology of the cascade refrigerating unit in the above field is mature, the following defects still exist: 1. because of the small latent heat of vaporization of R22, more R22 needs to be used under the same operating conditions, requiring a large screw compressor with a larger displacement. 2. When the ambient temperature is lower than 10 ℃, the low-temperature single machine operation cannot be realized. 3. The unit has a large compression ratio.

SUMMERY OF THE UTILITY MODEL

To the defect among the prior art, the utility model aims at providing an environment-friendly cascade refrigeration unit makes it needn't use the large-scale screw compressor of great displacement, can realize low temperature level single-stage operation to the compression ratio of unit is less.

In order to achieve the above purpose, the present invention is implemented by the following technical solutions: an environmentally friendly cascade refrigeration unit comprising:

a load-bearing platform;

a heat exchanger mounted on the load-bearing platform, the heat exchanger having a first inlet in communication with the first outlet, a second inlet in communication with the second outlet, and a second outlet;

the high-temperature stage refrigeration cycle system is arranged on the bearing platform and is positioned on one side of the heat exchanger, the refrigerant used in the high-temperature stage refrigeration cycle system is R134A, the high-temperature stage refrigeration cycle system comprises a first screw compressor, an evaporative condenser and a first liquid storage device, the inlet of the first screw compressor is connected with the first outlet, the evaporative condenser is provided with a third inlet, a third outlet, a fourth inlet and a fourth outlet, the third inlet is communicated with the third outlet, the fourth inlet is communicated with the fourth outlet, the fourth inlet is connected with the outlet of the first screw compressor, the fourth outlet is connected with the inlet of the first liquid storage device, and the outlet of the first liquid storage device is connected with the first inlet of the heat exchanger; and

low-temperature stage refrigeration cycle system, low-temperature stage refrigeration cycle system installs on the bearing platform, and be located the opposite side of heat exchanger, the refrigerant that uses in the low-temperature stage refrigeration cycle system is R410A, low-temperature stage refrigeration cycle system includes second reservoir, expansion valve, evaporimeter and second screw compressor, the entry of second reservoir with the second exit linkage, the export of second reservoir with the entry linkage of expansion valve, the export of expansion valve with the entry linkage of evaporimeter, the export of evaporimeter with the entry linkage of second screw compressor, the export of second screw compressor with third entry linkage, the third export with second entry linkage.

Further, the low-temperature stage refrigeration cycle system further comprises a heat regenerator, the heat regenerator is provided with a fifth inlet, a fifth outlet, a sixth inlet and a sixth outlet, the fifth inlet is communicated with the fifth outlet, the fifth inlet is connected with the outlet of the evaporator, the fifth outlet is connected with the inlet of the second screw compressor, the sixth inlet is communicated with the sixth outlet, the sixth inlet is connected with the outlet of the second liquid storage device, and the sixth outlet is connected with the inlet of the expansion valve.

Further, the heat exchanger is a plate heat exchanger.

Further, the expansion valve is a thermostatic expansion valve.

The utility model has the advantages that:

1. the utility model provides a pair of cascade refrigeration unit divide into low temperature level refrigeration cycle and high temperature level refrigeration cycle, and wherein the refrigerant in the low temperature level refrigeration cycle is R410A, and the refrigerant in the high temperature level refrigeration cycle is R134A. The latent heat of vaporization of the two refrigerants is large, so that a large screw compressor with large air displacement is not needed under the same working condition.

2. The utility model provides a pair of cascade refrigeration unit, novel refrigerant R410A and R134A's use, when fully guaranteeing unit environmental protection and security performance, still make the working property of unit obtain promoting greatly, if have less compression ratio, be less than 10 ℃ in ambient temperature can realize low temperature level single-stage operation etc..

Drawings

Fig. 1 is a schematic structural view of the present invention;

fig. 2 is an enlarged schematic view of a portion a in fig. 1.

Reference numerals: the system comprises a 10-heat exchanger, a 11-first inlet, a 12-first outlet, a 13-second inlet, a 14-second outlet, a 20-high-temperature stage refrigeration cycle system, a 21-first screw compressor, a 22-evaporative condenser, a 221-third inlet, a 222-third outlet, a 223-fourth inlet, a 224-fourth outlet, a 23-first liquid storage device, a 30-low-temperature stage refrigeration cycle system, a 31-second liquid storage device, a 32-expansion valve, a 33-evaporator, a 34-second screw compressor, a 35-heat regenerator, a 351-fifth inlet, a 352-fifth outlet, a 353-sixth inlet and a 354-sixth outlet.

Detailed Description

In order to make the technical means, creation features, achievement purposes and functions of the present invention easy to understand, the present invention is further described below with reference to the following embodiments.

In this application, unless expressly stated or limited otherwise, the terms "connected" and "fixed" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection, or an integral part; can be mechanically connected or connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present application, it is to be understood that the terms "longitudinal," "lateral," "horizontal," "top," "bottom," "upper," "lower," "inner" and "outer" and the like are used in the orientation or positional relationship shown in the drawings, which are used for convenience in describing the present invention and for simplicity in description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

As shown in fig. 1-2, the present invention provides an environment-friendly cascade refrigeration unit, which comprises a load-bearing platform (not shown in the drawings), a heat exchanger 10, a high-temperature refrigeration cycle system 20 and a low-temperature refrigeration cycle system 30.

The heat exchanger 10 is fixedly mounted on a load-bearing platform, the heat exchanger 10 having a first inlet 11, a first outlet 12, a second inlet 13 and a second outlet 14. The first inlet 11 communicates with the first outlet 12 and the second inlet 13 communicates with the second outlet 14.

The high-temperature stage refrigeration cycle system 20 is installed on the load-bearing platform and is located on one side of the heat exchanger 10, and the refrigerant used in the high-temperature stage refrigeration cycle system 20 is R134A. The high-temperature stage refrigeration cycle 20 includes a first screw compressor 21, an evaporative condenser 22, and a first accumulator 23. The inlet of the first screw compressor 21 is connected to the first outlet 12. The evaporative condenser 22 has a third inlet 221, a third outlet 222, a fourth inlet 223 and a fourth outlet 224, the third inlet 221 is communicated with the third outlet 222, the fourth inlet 223 is communicated with the fourth outlet 224, the fourth inlet 223 is connected with the outlet of the first screw compressor 21, and the fourth outlet 224 is connected with the inlet of the first accumulator 23. The outlet of the first reservoir 23 is connected to the first inlet 11 of the heat exchanger 10.

The low-temperature stage refrigeration cycle system 30 is installed on the load-bearing platform and is positioned at the other side of the heat exchanger 10, and the refrigerant used in the low-temperature stage refrigeration cycle system 30 is R410A. The low-temperature-stage refrigeration cycle system 30 includes a second accumulator 31, an expansion valve 32, an evaporator 33, and a second screw compressor 34. The inlet of the second accumulator 31 is connected to the second outlet 14, the outlet of the second accumulator 31 is connected to the inlet of the expansion valve 32, the outlet of the expansion valve 32 is connected to the inlet of the evaporator 33, the outlet of the evaporator 33 is connected to the inlet of the second screw compressor 34, and the outlet of the second screw compressor 34 is connected to the third inlet 221. The third outlet 222 is connected to the second inlet 13.

The specific working process of the high-temperature stage refrigeration cycle system 20 is as follows: the intermediate-temperature low-pressure R134A refrigerant vapor is discharged from the first outlet 12, enters the first screw compressor 21, and is compressed in the first screw compressor 21 into high-temperature high-pressure R134A refrigerant vapor. The high-temperature and high-pressure R134A refrigerant vapor is discharged from the outlet of the first screw compressor 21, enters the evaporative condenser 22 from the fourth inlet 223, releases heat to the cooling water in the evaporative condenser 22, and is condensed into R134A refrigerant liquid. The R134A refrigerant liquid is discharged from the fourth outlet 224, enters the first receiver 23, is discharged from the outlet of the first receiver 23, enters the heat exchanger 10 from the first inlet 11, absorbs heat of the low-temperature-stage refrigerant R410A flowing in from the second inlet 13 and discharged from the second outlet 14 in the heat exchanger 10, evaporates into R134A refrigerant vapor of medium temperature and low pressure, and the R134A refrigerant vapor of medium temperature and low pressure is discharged from the first outlet 12 and reenters the first screw compressor 21, thereby starting the next high-temperature-stage refrigeration cycle.

The specific working flow of the low-temperature stage refrigeration cycle system 3030 is as follows: the low-temperature and low-pressure refrigerant R410A enters the second screw compressor 34, is compressed into the R410A refrigerant vapor of intermediate temperature and high pressure in the second screw compressor 34, and the R410A refrigerant vapor of intermediate temperature and high pressure is discharged from the outlet of the second screw compressor 34, enters the evaporative condenser 22 from the third inlet 221, is reduced in temperature after releasing heat to the cooling water in the evaporative condenser 22, is discharged from the third outlet 222, flows into the heat exchanger 10 from the second inlet 13, exchanges heat with the R134A refrigerant liquid in the heat exchanger 10, and is condensed into the R410A refrigerant liquid. The R410A refrigerant liquid is discharged from the second outlet 14, enters the second accumulator 31, is discharged from the outlet of the second accumulator 31, enters the expansion valve 32, and is throttle-expanded in the expansion valve 32 to an intermediate-temperature low-pressure R410A refrigerant gas-liquid mixture. The R410A refrigerant gas-liquid mixture is discharged from the outlet of the expansion valve 32, enters the evaporator 33, absorbs the heat of the outside air in the evaporator 33, and is evaporated into a low-temperature and low-pressure R410A refrigerant vapor. The low temperature and low pressure R410A refrigerant vapor exits the outlet of the evaporator 33 and reenters the second screw compressor 34 to begin the next cycle of the low temperature refrigeration cycle.

The components of the machine are two refrigeration cycles of a low-temperature stage refrigeration cycle and a high-temperature stage refrigeration cycle, wherein the refrigerant in the low-temperature stage refrigeration cycle is R410A, and the refrigerant in the high-temperature stage refrigeration cycle is R134A. The two refrigeration cycles are overlapped together through the heat exchanger 10 and run simultaneously, the high-temperature stage refrigeration cycle absorbs the heat of the low-temperature stage refrigeration cycle, and the two refrigeration cycles cooperate to complete the whole refrigeration cycle.

Compare traditional doublestage compression cycle, this unit is mainly through two refrigeration cycle of heat exchanger 10 connection, and the system is simple, and two screw compressor's cylinder volume is littleer, and need not to consider system oil return inequality, the too big scheduling problem of pressure differential, and control is convenient, the experimental operation of being convenient for.

In addition, R410A and R134A are both novel environment-friendly refrigerants and have high vaporization latent heat values, so that a large screw compressor with large air displacement is not needed under the same working condition. The R134A and R410A refrigerants are fully utilized, so that the unit has a higher and more stable operation effect, the unit performance can be greatly improved, when the ambient temperature is lower than 10 ℃, the unit can only start the second screw compressor 34 to operate in a single-stage mode through reasonable system configuration, the seasonal energy efficiency ratio is greatly improved, and the COP value is higher. And because R410A and R134A are environment-friendly and nontoxic stable refrigerants, the safety and environmental protection performance of the unit are greatly ensured.

In one embodiment, the low temperature stage refrigeration cycle system 30 further includes a regenerator 35. Regenerator 35 has a fifth inlet 351, a fifth outlet 352, a sixth inlet 353 and a sixth outlet 354, fifth inlet 351 communicates with fifth outlet 352, and fifth inlet 351 is connected to the outlet of evaporator 33. The fifth outlet 352 is connected to the inlet of the second screw compressor 34, the sixth inlet 353 communicates with the sixth outlet 354, the sixth inlet 353 is connected to the outlet of the second accumulator 31, and the sixth outlet 354 is connected to the inlet of the expansion valve 32.

The design of the heat regenerator 35 enables the R410A refrigerant liquid discharged from the second accumulator 31 to exchange heat with the R410A refrigerant vapor of low temperature and low pressure discharged from the evaporator 33, so that the R410A refrigerant sucked back by the second screw compressor 34 is saturated superheated vapor, thereby achieving the purpose of avoiding liquid slugging of the second screw compressor 34.

In one embodiment, the heat exchanger 10 is a plate heat exchanger.

In one embodiment, the expansion valve 32 is a thermostatic expansion valve.

The basic principles and the main features of the invention and the advantages of the invention have been shown and described above, it will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, but that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides an environment-friendly cascade refrigeration unit which characterized in that: the method comprises the following steps:

a load-bearing platform;

2. The environmentally friendly cascade refrigeration unit of claim 1, wherein: the low-temperature-stage refrigeration cycle system further comprises a heat regenerator, wherein the heat regenerator is provided with a fifth inlet, a fifth outlet, a sixth inlet and a sixth outlet, the fifth inlet is communicated with the fifth outlet, the fifth inlet is connected with the outlet of the evaporator, the fifth outlet is connected with the inlet of the second screw compressor, the sixth inlet is communicated with the sixth outlet, the sixth inlet is connected with the outlet of the second liquid storage device, and the sixth outlet is connected with the inlet of the expansion valve.

3. The environmentally friendly cascade refrigeration unit of claim 1, wherein: the heat exchanger is a plate heat exchanger.

4. The environmentally friendly cascade refrigeration unit of claim 1, wherein: the expansion valve is a thermostatic expansion valve.