CN117366900A - Cascade compression refrigeration system, refrigeration device and control method - Google Patents
Cascade compression refrigeration system, refrigeration device and control method Download PDFInfo
- Publication number
- CN117366900A CN117366900A CN202210772082.6A CN202210772082A CN117366900A CN 117366900 A CN117366900 A CN 117366900A CN 202210772082 A CN202210772082 A CN 202210772082A CN 117366900 A CN117366900 A CN 117366900A
- Authority
- CN
- China
- Prior art keywords
- temperature
- preset
- stage
- throttling device
- switching valve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005057 refrigeration Methods 0.000 title claims abstract description 131
- 238000000034 method Methods 0.000 title claims abstract description 37
- 230000006835 compression Effects 0.000 title claims abstract description 18
- 238000007906 compression Methods 0.000 title claims abstract description 18
- 239000003507 refrigerant Substances 0.000 claims abstract description 135
- 238000001816 cooling Methods 0.000 claims abstract description 57
- 238000001704 evaporation Methods 0.000 claims abstract description 43
- 230000005494 condensation Effects 0.000 claims abstract description 36
- 238000009833 condensation Methods 0.000 claims abstract description 36
- 230000008020 evaporation Effects 0.000 claims abstract description 36
- 238000004891 communication Methods 0.000 description 13
- 230000006872 improvement Effects 0.000 description 11
- 230000008569 process Effects 0.000 description 5
- 238000004321 preservation Methods 0.000 description 4
- 235000013305 food Nutrition 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 230000017525 heat dissipation Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000037213 diet Effects 0.000 description 1
- 235000005911 diet Nutrition 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035764 nutrition Effects 0.000 description 1
- 235000016709 nutrition Nutrition 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B7/00—Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/37—Capillary tubes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/40—Fluid line arrangements
- F25B41/42—Arrangements for diverging or converging flows, e.g. branch lines or junctions
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
- F25B43/006—Accumulators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
- F25B49/022—Compressor control arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D11/00—Self-contained movable devices, e.g. domestic refrigerators
- F25D11/02—Self-contained movable devices, e.g. domestic refrigerators with cooling compartments at different temperatures
- F25D11/022—Self-contained movable devices, e.g. domestic refrigerators with cooling compartments at different temperatures with two or more evaporators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D11/00—Self-contained movable devices, e.g. domestic refrigerators
- F25D11/02—Self-contained movable devices, e.g. domestic refrigerators with cooling compartments at different temperatures
- F25D11/025—Self-contained movable devices, e.g. domestic refrigerators with cooling compartments at different temperatures using primary and secondary refrigeration systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D29/00—Arrangement or mounting of control or safety devices
- F25D29/003—Arrangement or mounting of control or safety devices for movable devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/02—Compressor control
- F25B2600/027—Compressor control by controlling pressure
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Analytical Chemistry (AREA)
- Power Engineering (AREA)
- Devices That Are Associated With Refrigeration Equipment (AREA)
Abstract
The invention provides a cascade compression refrigeration system, a refrigeration device and a control method, wherein the refrigeration system comprises a high-temperature-stage refrigeration circulation loop and a low-temperature-stage refrigeration circulation loop, the high-temperature-stage refrigeration circulation loop comprises a high-temperature-stage compressor, a switching valve, a parallel branch, a high-temperature-stage evaporator and a high-temperature-stage muffler connected with the high-temperature-stage evaporator and the high-temperature-stage compressor, the parallel branch comprises a first cooling branch and a second cooling branch which are arranged in parallel, the first cooling branch comprises a first throttling device, the second cooling branch comprises a second throttling device and an evaporation part which are arranged in series, the parallel branch also comprises a third throttling device connected in parallel with the second throttling device, and first refrigerant flowing through the first throttling device and the second throttling device respectively exchanges heat with first refrigerant flowing through the high-temperature-stage muffler; the low-temperature-stage refrigeration cycle loop comprises a condensation part, and the second refrigerant flowing through the condensation part exchanges heat with the first refrigerant flowing through the evaporation part, so that the problems of high starting pressure and low refrigeration efficiency when the low-temperature-stage compressor is started are solved.
Description
Technical Field
The invention relates to the technical field of refrigeration equipment, in particular to a cascade compression refrigeration system, a refrigeration device with the cascade compression refrigeration system and a control method of the refrigeration device.
Background
With the development of economy, the living standard of residents is greatly improved, the living concept is changed, the living concept of pursuing health, nutrition and balanced collocation is started, meanwhile, the pursuing of diversified diets is started, the variety of food materials and foods is also more and more abundant, but the requirements of different food materials on the storage temperature are different, so that higher requirements are provided for the refrigerating device, and different temperature areas are required to be configured.
The refrigeration device in the market at present often carries out refrigeration through overlapping compression refrigerating system to make different storing compartments have different temperature areas, however, the current refrigeration device generally has the problem that the starting pressure is big and refrigeration efficiency is low when the low temperature level compressor starts in the use.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a cascade compression refrigeration system, a refrigeration device with the cascade compression refrigeration system and a control method of the refrigeration device, so as to solve the problems that the existing refrigeration device is large in starting pressure and low in refrigeration efficiency when a low-temperature-level compressor is started in the use process.
In order to achieve one of the above objects, an embodiment of the present invention provides an cascade compression refrigeration system, comprising,
The high-temperature-stage refrigeration circulation loop comprises a high-temperature-stage compressor, a parallel branch, a switching valve arranged at the inlet of the parallel branch, a high-temperature-stage evaporator and a high-temperature-stage air return pipe for connecting the high-temperature-stage evaporator and the high-temperature-stage compressor, wherein a first refrigerant flows in the high-temperature-stage refrigeration circulation loop, the parallel branch comprises a first cooling branch and a second cooling branch which are arranged in parallel, the first cooling branch comprises a first throttling device, the second cooling branch comprises a second throttling device and an evaporation part which are arranged in series, the parallel branch further comprises a third throttling device which is arranged in parallel with the second throttling device, the first refrigerant flowing through the first throttling device and the first refrigerant flowing through the second throttling device exchange heat with the first refrigerant flowing through the high-temperature-stage air return pipe respectively, and the switching valve is selectively communicated with at least one of the first cooling branch, the second throttling device and the third throttling device;
the low-temperature-stage refrigeration cycle loop comprises a low-temperature-stage compressor and a condensation part, wherein a second refrigerant flows in the low-temperature-stage refrigeration cycle loop, and the second refrigerant flowing through the condensation part exchanges heat with the first refrigerant flowing through the evaporation part.
In order to achieve one of the above objects, an embodiment of the present invention further provides a refrigeration apparatus, which includes a box, and further includes a cascade compression refrigeration system as described above, wherein the box has a first storage compartment and a second storage compartment therein, the high-temperature-stage refrigeration cycle circuit cools the first storage compartment, and the low-temperature-stage refrigeration cycle circuit cools the second storage compartment.
As a further improvement of one embodiment of the present invention, the refrigeration apparatus further includes a controller, which is connected to the switching valve and is configured to,
if the switching valve is communicated with the first cold supply branch only and the high-temperature-stage compressor is in an operating state, the duration of the state that the switching valve is communicated with the first cold supply branch only is counted, and within a preset time T1, if the temperature T in the first storage compartment is within a preset time T1 1 Down to its preset shutdown temperature T 1 switch Judging the temperature T in the second storage room 2 Whether a first preset condition is met or not, wherein the first preset condition is as follows: at time T 2 The preset starting temperature T of the second storage compartment is not less than 2 open Or, at this time, the preset shutdown temperature T of the second storage compartment 2-pass valve <T 2 <T 2 open And before this moment T 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the switching valve is controlled to be switched to be communicated with the third throttling device only;
after a preset time t2, controlling the low-temperature-stage compressor to start;
after a preset time t3, the switching valve is controlled to be switched to be communicated with the second throttling device only.
As a further improvement of an embodiment of the invention, the controller is also adapted to,
if T 2 ≤T 0 Controlling the switching valve to be switched to be communicated with the second throttling device only;
and after a preset time t2, controlling the low-temperature-stage compressor to start.
As a further improvement of an embodiment of the invention, the controller is also adapted to,
if T 2 And if the first preset condition is not met, controlling the high-temperature-stage compressor to stop.
As a further improvement of an embodiment of the invention, the controller is also adapted to,
if the switching valve is only communicated with the first cold supply branch and the high-temperature-stage compressor is in an operating state, the duration of the state that the switching valve is only communicated with the first cold supply branch is counted, and after a preset time T1, if the temperature T in the first storage compartment is 1 Has not yet fallen to its preset shutdown temperature T 1 switch Or below, judging the temperature T in the second storage room 2 Whether a second preset condition is met or not, wherein the second preset condition is as follows: at time T 2 The preset starting temperature T of the second storage compartment is not less than 2 open Or, at this time, the preset shutdown temperature T of the second storage compartment 2-pass valve <T 2 <T 2 open And T is within T1 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the switching valve is controlled to be switched to be communicated with the third throttling device only;
after a preset time t2, controlling the low-temperature-stage compressor to start;
after a preset time t3, the switching valve is controlled to be switched to be communicated with the second throttling device only.
As a further improvement of an embodiment of the invention, the controller is also adapted to,
if T 2 ≤T 0 Controlling the switching valve to be switched to be communicated with the second throttling device only;
and after a preset time t2, controlling the low-temperature-stage compressor to start.
As a further improvement of an embodiment of the invention, the controller is also adapted to,
if T 2 If the second preset condition is met, the switching valve is in the state of being only in the first stateThe duration of the state in which a cold leg is in communication is timed.
In order to achieve one of the above objects, an embodiment of the present invention also provides a control method of a refrigeration apparatus, the control method including,
if the switching valve is only communicated with the first cold supply branch and the high-temperature-stage compressor is in an operating state, the duration of switching the switching valve to the state communicated with the first cold supply branch is counted, and within a preset time T1, if the temperature T in the first storage compartment is within a preset time T1 1 Down to its preset shutdown temperature T 1 switch Judging the temperature T in the second storage room 2 Whether a first preset condition is met or not, wherein the first preset condition is as follows: at time T 2 The preset starting temperature T of the second storage compartment is not less than 2 open Or, at this time, the preset shutdown temperature T of the second storage compartment 2-pass valve <T 2 <T 2 open And before this moment T 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the switching valve is controlled to be switched to be communicated with the third throttling device only;
after a preset time t2, controlling the low-temperature-stage compressor to start;
after a preset time t3, the switching valve is controlled to be switched to be communicated with the second throttling device only.
As a further improvement of one embodiment of the present invention, the control method further includes,
If T 2 ≤T 0 Controlling the switching valve to be switched to be communicated with the second throttling device only;
and after a preset time t2, controlling the low-temperature-stage compressor to start.
As a further improvement of one embodiment of the present invention, the control method further includes,
if T 2 And if the first preset condition is not met, controlling the high-temperature-stage compressor to stop.
As a further improvement of one embodiment of the present invention, the control method further includes,
if the switching valve is only communicated with the first cold supply branch and the high-temperature-stage compressor is in an operating state, the duration of the state that the switching valve is only communicated with the first cold supply branch is counted, after a preset time T1, if T 1 Is not yet reduced to T 1 switch Or below, then determine T 2 Whether a second preset condition is met or not, wherein the second preset condition is as follows: at time T 2 ≥T 2 open Alternatively, the time T 2-pass valve <T 2 <T 2 open And T is within T1 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the switching valve is controlled to be switched to be communicated with the third throttling device only;
after a preset time t2, controlling the low-temperature-stage compressor to start;
after a preset time t3, the switching valve is controlled to be switched to be communicated with the second throttling device only.
As a further improvement of one embodiment of the present invention, the control method further includes,
if T 2 ≤T 0 Controlling the switching valve to be switched to be communicated with the second throttling device only;
and after a preset time t2, controlling the low-temperature-stage compressor to start.
As a further improvement of one embodiment of the present invention, the control method further includes,
if T 2 And if the second preset condition is not met, the time duration of the state that the switching valve is communicated with the first cold supply branch is counted again.
Compared with the prior art, the invention has the following beneficial effects: according to the cascade compression refrigeration system, the refrigeration device with the cascade compression refrigeration system and the control method of the refrigeration device, when the first refrigerant flows in the first cooling branch, if the first refrigerant flows out of the second throttling device to the evaporation part in the high-temperature-level refrigeration cycle loop, the second refrigerant flowing through the condensation part exchanges heat with the first refrigerant flowing through the evaporation part, and the first refrigerant in the evaporation part can absorb the heat of the second refrigerant flowing through the condensation part, so that the temperature of the second refrigerant in the condensation part can be further reduced, the low-temperature-level refrigeration cycle loop is precooled, and the low-temperature-level refrigeration cycle loop can realize lower temperature; meanwhile, as the first refrigerant flowing through the first throttling device and the first refrigerant flowing through the second throttling device exchange heat with the first refrigerant flowing through the high-temperature-stage muffler respectively, the first refrigerant in the high-temperature-stage muffler can be utilized to cool the first refrigerants in the first throttling device and the second throttling device, the refrigerating capacity is increased, the air suction temperature of the high-temperature-stage compressor is increased, the temperature of the high-temperature-stage compressor is increased to the right of a ring Wen Zuo, the refrigerating efficiency of the high-temperature-stage compressor is improved, and the working efficiency of a high-temperature-stage refrigerating cycle loop is improved; when the low-temperature-stage compressor is started, the first refrigerant can circulate in the third throttling device, so that the problem of high starting pressure at the moment of starting the low-temperature-stage compressor can be solved.
Drawings
Fig. 1 is a schematic structural diagram of an cascade compression refrigeration system according to an embodiment of the invention.
Detailed Description
The present invention will be described in detail below with reference to specific embodiments shown in the drawings.
In the various illustrations of the invention, certain dimensions of structures or portions may be exaggerated relative to other structures or portions for convenience of illustration, and thus serve only to illustrate the basic structure of the inventive subject matter.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements or structures, these described elements should not be limited by these terms. These terms are only used to distinguish one such descriptive object from another.
The refrigerating device provided by the embodiment of the invention comprises a box body and a door body, wherein the box body is internally provided with a storage compartment, the door body is used for opening or closing the storage compartment, and the refrigerating device further comprises a refrigerating system which is arranged in the box body and supplies cold to the storage compartment. Specifically, the refrigerating device can be set as a refrigerator, a freezer and the like so as to meet the requirements of different users and different application scenes.
In this embodiment, the case has a first storage compartment and a second storage compartment, where the first storage compartment may be a refrigeration compartment or a freezing compartment, and the second storage compartment may be a temperature-changing compartment or a cryogenic compartment. The refrigeration system adopts an cascade compression refrigeration system 100, and specifically comprises a high-temperature-stage refrigeration cycle loop 1 and a low-temperature-stage refrigeration cycle loop 2.
For convenience of description, in this embodiment, the high-temperature-stage refrigeration cycle 1 is used to cool the first storage compartment, and the low-temperature-stage refrigeration cycle 2 is used to cool the second storage compartment. Of course, the two may be interchanged.
Of course, in other embodiments, other storage compartments besides the first storage compartment and the second storage compartment may be provided according to actual needs.
Referring to fig. 1, the high-temperature-stage refrigeration cycle 1 includes a high-temperature-stage compressor 11, a parallel branch, a high-temperature-stage evaporator 15, and a high-temperature-stage muffler 13 connecting the high-temperature-stage evaporator 15 and the high-temperature-stage compressor 11, which are disposed in series with each other, a first refrigerant flows through the high-temperature-stage refrigeration cycle 1, the parallel branch includes a first cooling branch and a second cooling branch disposed in parallel, the first cooling branch includes a first throttling device 161, the second cooling branch includes a second throttling device 162 and an evaporation unit 12 disposed in series, the parallel branch further includes a third throttling device 163 disposed in parallel with the second throttling device 162, and the first refrigerant flowing through the first throttling device 161 and the first refrigerant flowing through the second throttling device 162 exchange heat with the first refrigerant flowing through the high-temperature-stage muffler 13, respectively. The high-temperature-stage refrigeration cycle 1 further includes a switching valve 17 disposed at the inlet of the parallel branch, and the switching valve 17 is selectively communicated with at least one of the first cooling branch, the second throttling device 162 and the third throttling device 163, so as to selectively control the flow direction of the first refrigerant as required, thereby realizing different functions and refrigeration effects. In this way, the first storage compartment may achieve a temperature range of-30 to 10 ℃.
The low-temperature-stage refrigeration cycle 2 includes a condensation unit 21, and a second refrigerant flows through the low-temperature-stage refrigeration cycle 2, and the second refrigerant flowing through the condensation unit 21 exchanges heat with the first refrigerant flowing through the evaporation unit 12.
Thus, when the first refrigerant circulates in the first cooling branch, the high-temperature-stage evaporator 15 cools the first storage compartment; when the first refrigerant flows in the second cooling branch, the first refrigerant flows out from the second throttling device 162 to the evaporation part 12 in the high-temperature-stage refrigeration cycle 1, and the second refrigerant flowing through the condensation part 21 exchanges heat with the first refrigerant flowing through the evaporation part 12, so that the first refrigerant in the evaporation part 12 can absorb heat of the second refrigerant flowing through the condensation part 21, and the temperature of the second refrigerant in the condensation part 21 can be further reduced, and the low-temperature-stage refrigeration cycle 2 is precooled, so that the low-temperature-stage refrigeration cycle 2 can realize lower temperature; meanwhile, as the first refrigerant flowing through the first throttling device 161 and the first refrigerant flowing through the second throttling device 162 exchange heat with the first refrigerant flowing through the high-temperature-stage muffler 13 respectively, the first refrigerant in the high-temperature-stage muffler 13 can be utilized to cool the first refrigerant in the first throttling device 161 and the first refrigerant in the second throttling device 162, the refrigerating capacity is increased, and meanwhile, the suction temperature of the high-temperature-stage compressor 11 is increased to be about a ring Wen Zuo, the refrigerating efficiency of the high-temperature-stage compressor 11 is improved, and the working efficiency of the high-temperature-stage refrigeration cycle 1 is improved; when the low temperature stage compressor 22 is started, the first refrigerant can circulate in the third throttling device 163, so that the problem that the starting pressure is large at the moment of starting the low temperature stage compressor 22 can be solved, and by this reason, the temperature of the first refrigerant in the evaporation part 12 is too high or even reaches tens of degrees due to the large heat dissipation capacity of the condensation part 21 at the moment of starting the low temperature stage compressor 22, and when the first refrigerant flows into the high temperature stage muffler 13 to exchange heat with the second throttling device 162, the temperature of the first refrigerant in the second throttling device 162 is increased to reduce the flow of the first refrigerant, so that the evaporation part 12 cannot provide enough cold energy for the condensation part 21, and the starting pressure of the low temperature stage compressor 22 is large.
Preferably, the first throttling means 161, the second throttling means 162 and the third throttling means 163 are all capillary tubes.
The first throttling device 161 and the second throttling device 162 are respectively and thermally connected with the high-temperature-stage muffler 13 in a sleeving or abutting manner, so that the heat exchange efficiency of the first refrigerant flowing in the first throttling device and the second throttling device can be improved, and the energy utilization rate can be improved.
Further, the high-temperature-stage refrigeration cycle 1 further includes a high-temperature-stage dry filter 18 provided between the high-temperature-stage condenser 14 and the parallel branch, and a liquid-storage bag 19 provided between the evaporation-section high-temperature-stage evaporator 15 and the high-temperature-stage muffler 13.
The low-temperature-stage refrigeration cycle 2 further includes a low-temperature-stage compressor 22, a low-temperature-stage throttling device 23, a low-temperature-stage evaporator 24, and a first return air pipe section 25, which are arranged in series, and the condensing portion 21 is disposed between the low-temperature-stage compressor 22 and the low-temperature-stage throttling device 23.
Further, the second refrigerant flowing through the first air return pipe section 25 exchanges heat with the second refrigerant flowing through the low-temperature-stage throttling device 23. Thereby, the second refrigerant flowing through the first air return pipe section 25 can absorb the heat of the second refrigerant flowing through the low-temperature-stage throttling device 23, and the temperature of the second refrigerant flowing to the suction inlet of the low-temperature-stage compressor 22 is increased, so that the suction temperature of the low-temperature-stage compressor 22 is increased, the energy utilization rate of the low-temperature-stage refrigeration cycle 2 is increased, and the energy efficiency of the whole refrigeration device is improved.
Preferably, the low-temperature-stage throttling device 23 is a capillary tube, and the first air return pipe section 25 and the low-temperature-stage throttling device 23 are mutually sleeved or abutted, so that the heat exchange efficiency of the second refrigerant flowing in the two is improved, and the energy utilization rate is improved.
Further, the low-temperature-stage refrigeration cycle 2 further includes a second return air pipe section 26 and a heat release pipe section 27, the second return air pipe section 26 is provided between the low-temperature-stage evaporator 24 and the low-temperature-stage compressor 22, the heat release pipe section 27 is provided between the low-temperature-stage compressor 22 and the condensed portion 21, and the second refrigerant flowing through the second return air pipe section 26 exchanges heat with the second refrigerant flowing through the heat release pipe section 27. Therefore, the second refrigerant flowing through the second air return pipe section 26 can absorb the heat of the second refrigerant flowing through the heat release pipe section 27, the suction temperature of the low-temperature-stage compressor 22 is increased, the cold energy of the second refrigerant flowing from the heat release pipe section 27 to the condensation part 21 is reduced, the low-temperature-stage refrigeration cycle 2 can achieve lower temperature, the temperature of the second storage compartment can be adjusted within the temperature range of-60 to-20 ℃, the energy utilization rate of the low-temperature-stage refrigeration cycle 2 is increased, and the energy efficiency of the whole refrigeration device is improved.
Preferably, the second return air pipe section 26 is located between the first return air pipe section 25 and the low temperature stage compressor 22, so that the energy utilization rate of the low temperature stage refrigeration cycle 2 can be maximally improved.
The second air return pipe section 26 and the heat release pipe section 27 are mutually sleeved or abutted, so that the heat exchange efficiency of the second refrigerant flowing in the two is improved, and the energy utilization rate is improved.
Further, the low-temperature-stage refrigeration cycle 2 further includes a low-temperature-stage radiating pipe 28 provided between the low-temperature-stage compressor 22 and the radiator pipe section 27, and a low-temperature-stage drier-filter 29 provided between the condensing portion 21 and the low-temperature-stage throttling device 23. The second refrigerant flowing out of the low-temperature stage compressor 22 can be radiated by the low-temperature stage radiating pipe 28, so that the low-temperature stage refrigeration cycle 2 can achieve a lower temperature; the second refrigerant flowing out of the condensation unit 21 can be dried and filtered by the low-temperature-stage dry filter 29.
The first refrigerant and the second refrigerant may be the same refrigerant or may be different refrigerants.
In addition, the "high temperature" and "low temperature" in the "high temperature-stage refrigeration cycle 1" and the "low temperature-stage refrigeration cycle 2" are relatively speaking, and the evaporation temperature of the first refrigerant flowing through the high temperature-stage refrigeration cycle 1 is relatively higher than the evaporation temperature of the second refrigerant flowing through the low temperature-stage refrigeration cycle 2.
Further, the refrigerating device further comprises a controller connected to the switching valve 17 and configured to control the communication state of the switching valve 17 with the first cooling branch, the second throttling device 162 and the third throttling device 163 according to the temperatures of the first storage compartment and the second storage compartment.
In particular, the controller is used for controlling the operation of the device,
if the switching valve 17 is in communication with only the first cold supply branch and the high-temperature stage compressor 11 is in operation, the duration of the state in which the switching valve 17 is in communication with only the first cold supply branch is counted, and if the temperature T in the first storage compartment is within the preset time T1 1 Down to its preset shutdown temperature T 1 switch Judging the temperature T in the second storage room 2 Whether a first preset condition is met or not, wherein the first preset condition is as follows: at time T 2 The preset starting temperature T of the second storage compartment is not less than 2 open Or, at this time, the preset shutdown temperature T of the second storage compartment 2-pass valve <T 2 <T 2 open And before this moment T 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the control switching valve 17 is switched to communicate with only the third throttle 163;
after a preset time t2, the low-temperature-stage compressor 22 is controlled to start;
After a preset time t3, the control switching valve 17 is switched to communicate with only the second throttling device 162.
In this way, in the running process of the refrigerating device, the high-temperature-level refrigerating circulation loop starts to refrigerate the first storage compartment, and if the temperature in the first storage compartment is reduced to the preset shutdown temperature and refrigeration is not needed within the preset time t1, the temperature of the second storage compartment is judged, so that the condition that the temperature in the second storage compartment is too high due to the fact that the second storage compartment cannot be refrigerated for a long time is avoided, and the preservation of articles stored in the second storage compartment is not facilitated. If the preset time T1 is reached, the temperature T of the second storage compartment 2 Meets the first preset condition, namelyThe second storage compartment needs to be refrigerated and has a temperature T 2 Greater than a preset temperature T 0 When the switching valve 17 is controlled to be communicated with the third throttling device 163 only and the high-temperature-stage compressor 11 is controlled to start, the problem that the starting pressure is large at the moment of starting the low-temperature-stage compressor 22 can be solved, and the first refrigerant in the third throttling device 163 and the first refrigerant in the high-temperature-stage muffler 13 do not exchange heat, so that the reduction of the flow rate of the first refrigerant in the third throttling device 163 is avoided, the sufficient cold energy provided by the evaporation part 12 for the condensation part 21 is ensured, and the excessive pressure at the moment of starting the low-temperature-stage compressor 22 is avoided. Further, after the preset time t2, the evaporating portion 12 provides enough cooling capacity for the condensing portion 21, and at this time, the low-temperature-stage compressor 22 is started, and the low-temperature-stage refrigeration cycle 2 cools the second storage compartment. After a preset time t3, the low-temperature-stage compressor 22 is further operated stably, at this time, the switching valve 17 is controlled to be switched to be communicated with the second throttling device 162 only, and the first refrigerant flowing through the second throttling device 162 exchanges heat with the first refrigerant flowing through the high-temperature-stage air return pipe 13, so that the first refrigerant in the second throttling device 162 can be cooled by the first refrigerant in the high-temperature-stage air return pipe 13, the refrigerating capacity is increased, the suction temperature of the high-temperature-stage compressor 11 is increased to be about Wen Zuo, the refrigerating efficiency of the high-temperature-stage compressor 11 is improved, the cooling capacity of the evaporating part 12 to the condensing part 21 is further improved, the refrigerating efficiency of the low-temperature-stage refrigerating cycle 2 is improved, and the energy utilization rate of the refrigerating device is improved.
Preferably T 0 = -30-5 ℃ so that the actual temperature T of the second storage compartment can be avoided 2 When the pressure is too high, the problem of the low-temperature-stage compressor 22 having a large starting pressure occurs.
Preferably, t1=5 to 20min, so that not only can the high-temperature-stage refrigeration cycle 1 provide enough cooling capacity for the first storage compartment, but also the second storage compartment is prevented from being cooled for a long time.
Preferably, t2 is less than or equal to 5 minutes to ensure that the evaporator 12 provides sufficient cooling to the condenser 21 to avoid excessive starting pressure at the low temperature stage compressor 22.
Preferably, t3=0.5-10 min, by which the pressure of the low-temperature-stage compressor 22 can be stabilized, and the refrigeration efficiency of the low-temperature-stage refrigeration cycle 2 is improved, so that the temperature in the first storage compartment reaches the preset temperature as soon as possible, and the starting efficiency is improved.
Further, the controller is also used for controlling the operation of the device,
if T 2 ≤T 0 The control switching valve 17 is switched to communicate with only the second throttling device 162;
after a preset time t2, the low temperature stage compressor 22 is controlled to start.
In the operating state of the refrigeration device, when the second storage compartment needs refrigeration, the temperature T of the second storage compartment 2 Not greater than a preset temperature T 0 At this time, the evaporation unit 12 may directly supply the cooling to the condensation unit 21 through the second throttling device 162, so that the cooling capacity of the evaporation unit 12 to the condensation unit 21 may be increased by exchanging heat between the first refrigerant flowing through the second throttling device 162 and the first refrigerant flowing through the high-temperature-stage air return pipe 13, thereby accelerating the pre-cooling efficiency and further increasing the cooling efficiency of the second storage compartment.
Further, the controller is also used for controlling the operation of the device,
if T 2 And if the first preset condition is not met, controlling the high-temperature-stage compressor 11 to stop.
That is, if the temperature of the first storage compartment is reduced to the preset shutdown temperature T within the preset time T1 1 switch And the temperature of the second storage compartment also reaches the preset shutdown temperature T 2-pass valve Or the shutdown condition of the second storage compartment is satisfied, the high-temperature-stage compressor 11 may be stopped to save energy consumption.
Further, the controller is also used for controlling the operation of the device,
if the switching valve 17 is in communication with only the first cold supply branch and the high temperature stage compressor 11 is in operation, the duration of the state in which the switching valve 17 is in communication with only the first cold supply branch is counted, and after a preset time T1, if the temperature T in the first storage compartment is 1 Has not yet fallen to its preset limitMachine temperature T 1 switch Or below, judging the temperature T in the second storage room 2 Whether a second preset condition is met or not, wherein the second preset condition is as follows: at time T 2 ≥T 2 open Alternatively, T 2-pass valve <T 2 <T 2 open And T is within T1 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the control switching valve 17 is switched to communicate with only the third throttle 163;
After a preset time t2, the low-temperature-stage compressor 22 is controlled to start;
after a preset time t3, the control switching valve 17 is switched to communicate with only the second throttling device 162.
In this way, in the running process of the refrigerating device, the high-temperature-level refrigerating circulation loop starts to refrigerate the first storage compartment, and after the preset time t1, if the temperature in the first storage compartment is not reduced to the preset shutdown temperature, whether the second storage compartment needs to refrigerate is judged first, so that the situation that the temperature in the second storage compartment is too high due to the fact that the second storage compartment cannot refrigerate for a long time is avoided, and the preservation of the articles stored in the second storage compartment is not facilitated. If the second storage compartment needs to be refrigerated after the preset time T1, the temperature T of the second storage compartment 2 Greater than a preset temperature T 0 By controlling the switching valve 17 to be switched to communicate with only the third throttling device 163 and controlling the high temperature stage compressor 11 to be started, the problem of large starting pressure at the moment of starting the low temperature stage compressor 22 can be solved, and because the first refrigerant in the third throttling device 163 and the first refrigerant in the high temperature stage muffler 13 do not generate heat exchange, the first refrigerant flow in the third throttling device 163 is prevented from being reduced, the evaporating part 12 is ensured to provide enough cold energy for the condensing part 21, and the moment of starting the low temperature stage compressor 22 is prevented from being excessively high. Further, after the preset time t2, the evaporating portion 12 provides enough cooling capacity for the condensing portion 21, and at this time, the low-temperature-stage compressor 22 is started, and the low-temperature-stage refrigeration cycle 2 cools the second storage compartment. After a further preset time t3, the low temperature stage compressor 22 is operated The switching valve 17 is controlled to be communicated with the second throttling device 162 only, and the first refrigerant flowing through the second throttling device 162 exchanges heat with the first refrigerant flowing through the high-temperature-stage air return pipe 13, so that the first refrigerant in the high-temperature-stage air return pipe 13 can be used for cooling the first refrigerant in the second throttling device 162, the refrigerating capacity is increased, the suction temperature of the high-temperature-stage compressor 11 is increased, the temperature of the high-temperature-stage compressor 11 is increased to the right of the ring Wen Zuo, the refrigerating efficiency of the high-temperature-stage compressor 11 is improved, the cooling capacity of the evaporation part 12 to the condensation part 21 is further improved, the refrigerating efficiency of the low-temperature-stage refrigeration cycle 2 is improved, and the energy utilization rate of the refrigerating device is improved.
Further, the controller is further configured to:
if T 2 ≤T 0 The control switching valve 17 is switched to communicate with only the second throttling device 162;
after a preset time t2, the low temperature stage compressor 22 is controlled to start.
In the operating state of the refrigeration device, when the second storage compartment needs refrigeration, the temperature T of the second storage compartment 2 Not greater than a preset temperature T 0 At this time, the evaporation unit 12 may directly supply the cooling to the condensation unit 21 through the second throttling device 162, so that the cooling capacity of the evaporation unit 12 to the condensation unit 21 may be increased by exchanging heat between the first refrigerant flowing through the second throttling device 162 and the first refrigerant flowing through the high-temperature-stage air return pipe 13, thereby accelerating the pre-cooling efficiency and further increasing the cooling efficiency of the second storage compartment.
Further, the controller is further configured to:
if T 2 The second preset condition is not satisfied, the duration of the state in which the switching valve 17 is in communication with only the first cold supply branch is again counted.
That is, after the preset time T1, if the temperature of the first storage compartment has not been reduced to the preset shutdown temperature T 1 switch The temperature of the second storage compartment is reduced to a preset shutdown temperature T 2-pass valve Or meets the shutdown condition of the second storage compartment, and requires the high-temperature-stage compressor 11 to continue to operate to cool the first storage compartmentBy re-timing the duration of the switching valve 17 in a state of communication with only the first cold supply branch, a new cycle of temperature monitoring and compressor operating state control is performed.
An embodiment of the present invention also provides a control method of the refrigerating apparatus as described above, which includes,
if the switching valve 17 is in communication with only the first cold supply branch and the high-temperature stage compressor 11 is in operation, the duration of the state in which the switching valve 17 is in communication with only the first cold supply branch is counted, and if the temperature T in the first storage compartment is within the preset time T1 1 Down to its preset shutdown temperature T 1 switch Judging the temperature T in the second storage room 2 Whether a first preset condition is met or not, wherein the first preset condition is as follows: at time T 2 The preset starting temperature T of the second storage compartment is not less than 2 open Or, at this time, the preset shutdown temperature T of the second storage compartment 2-pass valve <T 2 <T 2 open And before this moment T 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the control switching valve 17 is switched to communicate with only the third throttle 163;
after a preset time t2, the low-temperature-stage compressor 22 is controlled to start;
after a preset time t3, the control switching valve 17 is switched to communicate with only the second throttling device 162.
In this way, in the running process of the refrigerating device, the high-temperature-level refrigerating circulation loop starts to refrigerate the first storage compartment, and if the temperature in the first storage compartment is reduced to the preset shutdown temperature and refrigeration is not needed within the preset time t1, the temperature of the second storage compartment is judged, so that the condition that the temperature in the second storage compartment is too high due to the fact that the second storage compartment cannot be refrigerated for a long time is avoided, and the preservation of articles stored in the second storage compartment is not facilitated. If the preset time T1 is reached, the temperature T of the second storage compartment 2 Meets the first preset condition, namely the second storage roomThe chamber requiring refrigeration and having a temperature T 2 Greater than a preset temperature T 0 When the switching valve 17 is controlled to be communicated with the third throttling device 163 only and the high-temperature-stage compressor 11 is controlled to start, the problem that the starting pressure is large at the moment of starting the low-temperature-stage compressor 22 can be solved, and the first refrigerant in the third throttling device 163 and the first refrigerant in the high-temperature-stage muffler 13 do not exchange heat, so that the reduction of the flow rate of the first refrigerant in the third throttling device 163 is avoided, the sufficient cold energy provided by the evaporation part 12 for the condensation part 21 is ensured, and the excessive pressure at the moment of starting the low-temperature-stage compressor 22 is avoided. Further, after the preset time t2, the evaporating portion 12 provides enough cooling capacity for the condensing portion 21, and at this time, the low-temperature-stage compressor 22 is started, and the low-temperature-stage refrigeration cycle 2 cools the second storage compartment. After a preset time t3, the low-temperature-stage compressor 22 is further operated stably, at this time, the switching valve 17 is controlled to be switched to be communicated with the second throttling device 162 only, and the first refrigerant flowing through the second throttling device 162 exchanges heat with the first refrigerant flowing through the high-temperature-stage air return pipe 13, so that the first refrigerant in the second throttling device 162 can be cooled by the first refrigerant in the high-temperature-stage air return pipe 13, the refrigerating capacity is increased, the suction temperature of the high-temperature-stage compressor 11 is increased to be about Wen Zuo, the refrigerating efficiency of the high-temperature-stage compressor 11 is improved, the cooling capacity of the evaporating part 12 to the condensing part 21 is further improved, the refrigerating efficiency of the low-temperature-stage refrigerating cycle 2 is improved, and the energy utilization rate of the refrigerating device is improved.
Preferably T 0 = -30-5 ℃ so that the actual temperature T of the second storage compartment can be avoided 2 When the pressure is too high, the problem of the low-temperature-stage compressor 22 having a large starting pressure occurs.
Preferably, t1=5 to 20min, so that not only can the high-temperature-stage refrigeration cycle 1 provide enough cooling capacity for the first storage compartment, but also the second storage compartment is prevented from being cooled for a long time.
Preferably, t2 is less than or equal to 5 minutes to ensure that the evaporator 12 provides sufficient cooling to the condenser 21 to avoid excessive starting pressure at the low temperature stage compressor 22.
Preferably, t3=0.5-10 min, by which the pressure of the low-temperature-stage compressor 22 can be stabilized, and the refrigeration efficiency of the low-temperature-stage refrigeration cycle 2 is improved, so that the temperature in the first storage compartment reaches the preset temperature as soon as possible, and the starting efficiency is improved.
Further, the control method further comprises,
if T 2 ≤T 0 The control switching valve 17 is switched to communicate with only the second throttling device 162;
after a preset time t2, the low temperature stage compressor 22 is controlled to start.
In the operating state of the refrigeration device, when the second storage compartment needs refrigeration, the temperature T of the second storage compartment 2 Not greater than a preset temperature T 0 At this time, the evaporation unit 12 may directly supply the cooling to the condensation unit 21 through the second throttling device 162, so that the cooling capacity of the evaporation unit 12 to the condensation unit 21 may be increased by exchanging heat between the first refrigerant flowing through the second throttling device 162 and the first refrigerant flowing through the high-temperature-stage air return pipe 13, thereby accelerating the pre-cooling efficiency and further increasing the cooling efficiency of the second storage compartment.
Further, the control method further comprises,
if T 2 And if the first preset condition is not met, controlling the high-temperature-stage compressor 11 to stop.
That is, if the temperature of the first storage compartment is reduced to the preset shutdown temperature T within the preset time T1 1 switch And the temperature of the second storage compartment also reaches the preset shutdown temperature T 2-pass valve Or the shutdown condition of the second storage compartment is satisfied, the high-temperature-stage compressor 11 may be stopped to save energy consumption.
Further, the control method further comprises,
if the switching valve 17 is in communication with only the first cold supply branch and the high temperature stage compressor 11 is in operation, the duration of the state in which the switching valve 17 is in communication with only the first cold supply branch is counted, and after a preset time T1, if the temperature T in the first storage compartment is 1 Has not yet fallen to its preset shutdown temperature T 1 switch Or below, judging the temperature T in the second storage room 2 Whether a second preset condition is met or not, wherein the second preset condition is as follows: at time T 2 ≥T 2 open Alternatively, T 2-pass valve <T 2 <T 2 open And T is within T1 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the control switching valve 17 is switched to communicate with only the third throttle 163;
After a preset time t2, the low-temperature-stage compressor 22 is controlled to start;
after a preset time t3, the control switching valve 17 is switched to communicate with only the second throttling device 162.
In this way, in the running process of the refrigerating device, the high-temperature-level refrigerating circulation loop starts to refrigerate the first storage compartment, after the preset time t1, if the temperature in the first storage compartment is not reduced to the preset shutdown temperature, whether the second storage compartment needs to refrigerate is judged first, so that the situation that the temperature in the second storage compartment is too high due to the fact that the second storage compartment cannot refrigerate for a long time is avoided, and the preservation of the articles stored in the second storage compartment is not facilitated. If the second storage compartment needs to be refrigerated after the preset time T1, the temperature T of the second storage compartment 2 Greater than a preset temperature T 0 When the switching valve 17 is controlled to be communicated with the third throttling device 163 only and the high-temperature-stage compressor 11 is controlled to start, the problem that the starting pressure is large at the moment of starting the low-temperature-stage compressor 22 can be solved, and the first refrigerant in the third throttling device 163 and the first refrigerant in the high-temperature-stage muffler 13 do not exchange heat, so that the reduction of the flow rate of the first refrigerant in the third throttling device 163 is avoided, the sufficient cold energy provided by the evaporation part 12 for the condensation part 21 is ensured, and the excessive pressure at the moment of starting the low-temperature-stage compressor 22 is avoided. Further, after the preset time t2, the evaporating portion 12 provides enough cooling capacity for the condensing portion 21, and at this time, the low-temperature-stage compressor 22 is started, and the low-temperature-stage refrigeration cycle 2 cools the second storage compartment. After a further preset time t3, the low-temperature-stage compressor 22 is operated stably At this time, the switching valve 17 is controlled to be switched to be communicated with only the second throttling device 162, and the first refrigerant flowing through the second throttling device 162 exchanges heat with the first refrigerant flowing through the high-temperature-stage air return pipe 13, so that the first refrigerant in the high-temperature-stage air return pipe 13 can be used for cooling the first refrigerant in the second throttling device 162, the refrigerating capacity is increased, the suction temperature of the high-temperature-stage compressor 11 is increased, the temperature of the high-temperature-stage compressor 11 is increased to the right of the ring Wen Zuo, the refrigerating efficiency of the high-temperature-stage compressor 11 is improved, the cooling capacity of the evaporation part 12 to the condensation part 21 is further improved, the refrigerating efficiency of the low-temperature-stage refrigeration cycle 2 is improved, and the energy utilization rate of the refrigerating device is improved.
Further, the control method further includes:
if T 2 ≤T 0 The control switching valve 17 is switched to communicate with only the second throttling device 162;
after a preset time t2, the low temperature stage compressor 22 is controlled to start.
In the operating state of the refrigeration device, when the second storage compartment needs refrigeration, the temperature T of the second storage compartment 2 Not greater than a preset temperature T 0 At this time, the evaporation unit 12 may directly supply the cooling to the condensation unit 21 through the second throttling device 162, so that the cooling capacity of the evaporation unit 12 to the condensation unit 21 may be increased by exchanging heat between the first refrigerant flowing through the second throttling device 162 and the first refrigerant flowing through the high-temperature-stage air return pipe 13, thereby accelerating the pre-cooling efficiency and further increasing the cooling efficiency of the second storage compartment.
Further, the control method further includes:
if T 2 The second preset condition is not satisfied, the duration of the state in which the switching valve 17 is in communication with only the first cold supply branch is again counted.
Then the above steps are circulated, i.e. within a preset time T1, if T 1 Down to T 1 switch Then judge T 2 Whether the first preset condition is met or not, and executing the subsequent steps.
That is, after the preset time T1, if the temperature of the first storage compartment has not been reduced to the preset shutdown temperature T 1 switch The temperature of the second storage compartment is reduced to a preset shutdown temperature T 2-pass valve Or the shutdown condition of the second storage compartment is met, and the high-temperature-stage compressor 11 is required to continue to operate at the moment, so as to cool the first storage compartment, and the duration of the state that the switching valve 17 is only communicated with the first cooling branch is rechemated, and a new round of temperature monitoring and compressor operation state control are performed.
Compared with the prior art, the cascade compression refrigeration system 100, the refrigeration device with the cascade compression refrigeration system and the control method of the refrigeration device provided by the invention have the beneficial effects that: the switching valve 17 selectively controls the flow direction of the first refrigerant as needed to achieve different functions and refrigeration effects; the high-temperature-stage evaporator 15 supplies cold for the first storage compartment when the first refrigerant circulates in the first cold supply branch; when the first refrigerant flows in the second cooling branch, if the first refrigerant flows out from the second throttling device 162 to the evaporation portion 12 in the high-temperature-stage refrigeration cycle 1, the second refrigerant flowing through the condensation portion 21 exchanges heat with the first refrigerant flowing through the evaporation portion 12, and the first refrigerant in the evaporation portion 12 can absorb heat of the second refrigerant flowing through the condensation portion 21, so that the temperature of the second refrigerant in the condensation portion 21 can be further reduced, and the low-temperature-stage refrigeration cycle 2 is precooled, so that the low-temperature-stage refrigeration cycle 2 can realize lower temperature; meanwhile, as the first refrigerant flowing through the first throttling device 161 and the first refrigerant flowing through the second throttling device 162 exchange heat with the first refrigerant flowing through the high-temperature-stage muffler 13 respectively, the first refrigerant in the high-temperature-stage muffler 13 can be utilized to cool the first refrigerant in the first throttling device 161 and the first refrigerant in the second throttling device 162, the refrigerating capacity is increased, and meanwhile, the suction temperature of the high-temperature-stage compressor 11 is increased to be about a ring Wen Zuo, the refrigerating efficiency of the high-temperature-stage compressor 11 is improved, and the working efficiency of the high-temperature-stage refrigeration cycle 1 is improved; when the low temperature stage compressor 22 is started, the first refrigerant can circulate in the third throttling device 163, so that the problem that the starting pressure is large at the moment of starting the low temperature stage compressor 22 can be solved, and by this reason, the temperature of the first refrigerant in the evaporation part 12 is too high or even reaches tens of degrees due to the large heat dissipation capacity of the condensation part 21 at the moment of starting the low temperature stage compressor 22, and when the first refrigerant flows into the high temperature stage muffler 13 to exchange heat with the second throttling device 162, the temperature of the first refrigerant in the second throttling device 162 is increased to reduce the flow of the first refrigerant, so that the evaporation part 12 cannot provide enough cold energy for the condensation part 21, and the starting pressure of the low temperature stage compressor 22 is large.
It should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is for clarity only, and that the skilled artisan should recognize that the embodiments may be combined as appropriate to form other embodiments that will be understood by those skilled in the art.
The above list of detailed descriptions is only specific to practical embodiments of the present invention, and they are not intended to limit the scope of the present invention, and all equivalent embodiments or modifications that do not depart from the spirit of the present invention should be included in the scope of the present invention.
Claims (14)
1. An cascade compression refrigeration system, comprising,
the high-temperature-stage refrigeration circulation loop comprises a high-temperature-stage compressor, a parallel branch, a switching valve arranged at the inlet of the parallel branch, a high-temperature-stage evaporator and a high-temperature-stage air return pipe for connecting the high-temperature-stage evaporator and the high-temperature-stage compressor, wherein a first refrigerant flows in the high-temperature-stage refrigeration circulation loop, the parallel branch comprises a first cooling branch and a second cooling branch which are arranged in parallel, the first cooling branch comprises a first throttling device, the second cooling branch comprises a second throttling device and an evaporation part which are arranged in series, the parallel branch further comprises a third throttling device which is arranged in parallel with the second throttling device, the first refrigerant flowing through the first throttling device and the first refrigerant flowing through the second throttling device exchange heat with the first refrigerant flowing through the high-temperature-stage air return pipe respectively, and the switching valve is selectively communicated with at least one of the first cooling branch, the second throttling device and the third throttling device;
The low-temperature-stage refrigeration cycle loop comprises a low-temperature-stage compressor and a condensation part, wherein a second refrigerant flows in the low-temperature-stage refrigeration cycle loop, and the second refrigerant flowing through the condensation part exchanges heat with the first refrigerant flowing through the evaporation part.
2. The refrigeration device comprises a box body, and further comprises a cascade compression refrigeration system as claimed in claim 1, wherein the box body is provided with a first storage compartment and a second storage compartment, the high-temperature-level refrigeration cycle loop is used for cooling the first storage compartment, and the low-temperature-level refrigeration cycle loop is used for cooling the second storage compartment.
3. The refrigeration unit of claim 2, further comprising a controller coupled to said switching valve and configured to,
if the switching valve is communicated with the first cold supply branch only and the high-temperature-stage compressor is in an operating state, the duration of the state that the switching valve is communicated with the first cold supply branch only is counted, and within a preset time T1, if the temperature T in the first storage compartment is within a preset time T1 1 Down to its preset shutdown temperature T 1 switch Judging the temperature T in the second storage room 2 Whether a first preset condition is met or not, wherein the first preset condition is as follows: at time T 2 The preset starting temperature T of the second storage compartment is not less than 2 open Or, at this time, the preset shutdown temperature T of the second storage compartment 2-pass valve <T 2 <T 2 open And before this moment T 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the switching valve is controlled to be switched to be communicated with the third throttling device only;
after a preset time t2, controlling the low-temperature-stage compressor to start;
after a preset time t3, the switching valve is controlled to be switched to be communicated with the second throttling device only.
4. A refrigeration device according to claim 3 wherein the controller is further configured to,
if T 2 ≤T 0 Controlling the switching valve to be switched to be communicated with the second throttling device only;
and after a preset time t2, controlling the low-temperature-stage compressor to start.
5. A refrigeration device according to claim 3 wherein the controller is further configured to,
if T 2 And if the first preset condition is not met, controlling the high-temperature-stage compressor to stop.
6. A refrigeration unit as recited in claim 2 wherein said controller is further configured to,
If the switching valve is only communicated with the first cold supply branch and the high-temperature-stage compressor is in an operating state, the duration of the state that the switching valve is only communicated with the first cold supply branch is counted, and after a preset time T1, if the temperature T in the first storage compartment is 1 Has not yet fallen to its preset shutdown temperature T 1 switch Or below, judging the temperature T in the second storage room 2 Whether a second preset condition is met or not, wherein the second preset condition is as follows: at time T 2 The preset starting temperature T of the second storage compartment is not less than 2 open Or, at this time, the preset shutdown temperature T of the second storage compartment 2-pass valve <T 2 <T 2 open And T is within T1 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the switching valve is controlled to be switched to be communicated with the third throttling device only;
after a preset time t2, controlling the low-temperature-stage compressor to start;
after a preset time t3, the switching valve is controlled to be switched to be communicated with the second throttling device only.
7. The refrigeration unit of claim 6 wherein said controller is further configured to,
if T 2 ≤T 0 Controlling the switching valve to be switched to be communicated with the second throttling device only;
And after a preset time t2, controlling the low-temperature-stage compressor to start.
8. The refrigeration unit of claim 6 wherein said controller is further configured to,
if T 2 And if the second preset condition is not met, the time duration of the state that the switching valve is communicated with the first cold supply branch is counted again.
9. A control method of a refrigeration apparatus according to claim 2, wherein the control method includes,
if the switching valve is communicated with the first cold supply branch only and the high-temperature-stage compressor is in an operating state, the duration of the state that the switching valve is communicated with the first cold supply branch only is counted, and within a preset time T1, if the temperature T in the first storage compartment is within a preset time T1 1 Down to its preset shutdown temperature T 1 switch Judging the temperature T in the second storage room 2 Whether a first preset condition is met or not, wherein the first preset condition is as follows: at time T 2 The preset starting temperature T of the second storage compartment is not less than 2 open Or, at this time, the preset shutdown temperature T of the second storage compartment 2-pass valve <T 2 <T 2 open And before this moment T 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the switching valve is controlled to be switched to be communicated with the third throttling device only;
after a preset time t2, controlling the low-temperature-stage compressor to start;
after a preset time t3, the switching valve is controlled to be switched to be communicated with the second throttling device only.
10. A control method of a refrigeration unit as recited in claim 9, wherein said control method further comprises,
if T 2 ≤T 0 Controlling the switching valve to be switched to be communicated with the second throttling device only;
and after a preset time t2, controlling the low-temperature-stage compressor to start.
11. A control method of a refrigeration unit as recited in claim 9, wherein said control method further comprises,
if T 2 And if the first preset condition is not met, controlling the high-temperature-stage compressor to stop.
12. A control method of a refrigeration unit as recited in claim 9, wherein said control method further comprises,
if the switching valve is only communicated with the first cold supply branch and the high-temperature-stage compressor is in an operating state, the duration of the state that the switching valve is only communicated with the first cold supply branch is counted, after a preset time T1, if T 1 Is not yet reduced to T 1 switch Or below, then determine T 2 Whether a second preset condition is met or not, wherein the second preset condition is as follows: at time T 2 ≥T 2 open Alternatively, the time T 2-pass valve <T 2 <T 2 open And T is within T1 2 Always greater than T 2-pass valve ；
If yes, judge T 2 Whether or not it is greater than a preset temperature T 0 ；
If yes, the switching valve is controlled to be switched to be communicated with the third throttling device only;
after a preset time t2, controlling the low-temperature-stage compressor to start;
after a preset time t3, the switching valve is controlled to be switched to be communicated with the second throttling device only.
13. A control method of a refrigeration unit as recited in claim 9, wherein said control method further comprises,
if T 2 ≤T 0 Controlling the switching valve to be switched to be communicated with the second throttling device only;
and after a preset time t2, controlling the low-temperature-stage compressor to start.
14. A control method of a refrigeration unit as recited in claim 9, wherein said control method further comprises,
if T 2 And if the second preset condition is not met, the time duration of the state that the switching valve is communicated with the first cold supply branch is counted again.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210772082.6A CN117366900A (en) | 2022-06-30 | 2022-06-30 | Cascade compression refrigeration system, refrigeration device and control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210772082.6A CN117366900A (en) | 2022-06-30 | 2022-06-30 | Cascade compression refrigeration system, refrigeration device and control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117366900A true CN117366900A (en) | 2024-01-09 |
Family
ID=89398957
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210772082.6A Pending CN117366900A (en) | 2022-06-30 | 2022-06-30 | Cascade compression refrigeration system, refrigeration device and control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117366900A (en) |
-
2022
- 2022-06-30 CN CN202210772082.6A patent/CN117366900A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20040040341A1 (en) | Refrigerator | |
| CN101526279A (en) | Cold recovery double-mode overlapping low-temperature refrigerator | |
| CN111207534A (en) | Refrigeration system, refrigeration equipment and control method of refrigeration system | |
| JP3975664B2 (en) | Refrigerating refrigerator, operation method of freezing refrigerator | |
| US5916254A (en) | Method of circulating refridgerant for defrosting and refrigerator employing the same | |
| CN203203293U (en) | Refrigerating and heating system for air source heat pump | |
| CN215892860U (en) | Refrigerating system for refrigerating and freezing device and refrigerating and freezing device | |
| JP4178646B2 (en) | refrigerator | |
| CN110849011A (en) | Refrigerator and operation method thereof | |
| CN218096667U (en) | Cascade compression refrigeration system, refrigerating plant | |
| JP3847499B2 (en) | Two-stage compression refrigeration system | |
| JP3576040B2 (en) | Cooling systems and refrigerators | |
| CN212720353U (en) | Refrigerator car and refrigerating system thereof | |
| CN117006800A (en) | Low-temperature refrigerator, cascade refrigeration system and starting control method thereof | |
| CN111520942A (en) | Refrigerator with a door | |
| CN117366900A (en) | Cascade compression refrigeration system, refrigeration device and control method | |
| CN218096664U (en) | Cascade compression refrigeration system and refrigeration device | |
| CN218096665U (en) | Cascade compression refrigeration system and refrigeration device with same | |
| CN212205125U (en) | Cascade compression refrigeration system and have its cold-stored refrigeration device | |
| CN117366899A (en) | Cascade compression refrigeration system, refrigeration device and control method | |
| CN104061750A (en) | Method For Controlling Refrigerator | |
| CN211372812U (en) | Refrigerator | |
| CN218179339U (en) | Refrigerating device | |
| CN117366893A (en) | Cascade compression refrigeration system, refrigeration device and control method thereof | |
| CN218096780U (en) | Refrigerating device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication |