CN114543380A

CN114543380A - Refrigeration device and bleed method therefor

Info

Publication number: CN114543380A
Application number: CN202011340992.4A
Authority: CN
Inventors: 米廷灿; 田海
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2022-05-27

Abstract

The invention provides a refrigeration device and a discharge method for the same. The refrigerating device includes: a compressor comprising a compressor inlet and a compressor outlet; a condenser downstream of the compressor outlet; a first valve downstream of the condenser; and at least one flow path downstream of the first valve, each of the at least one flow path including a flow regulating valve to control a flow of refrigerant into the at least one flow path; wherein the first valve and the flow regulating valve are normally closed valves, and wherein the refrigeration system further comprises a bleed flow path connected between the first valve and the flow regulating valve, thereby allowing fluid between the first valve and the flow regulating valve to bleed when the first valve and the flow regulating valve are closed. The embodiment of the invention effectively discharges the fluid in the closed pipeline and prevents high pressure from being generated.

Description

Refrigeration device and bleed method therefor

Technical Field

The invention relates to the field of refrigeration, in particular to a vehicle-mounted refrigeration device and a discharge method for the same.

Background

Conventional refrigerated freight trucks or refrigerated tractor-trailers include a cold box and a refrigeration system. Refrigeration systems typically include a compressor, a condenser, an expansion valve, and an evaporator. The evaporator of the refrigeration system is, for example, arranged in a cold box to provide cooling. The refrigeration systems described above are connected in series in a closed refrigerant circuit by refrigerant lines according to a known refrigerant vapor compression cycle. The compressor of the refrigeration system may be driven by the engine of the vehicle, and some of the electrical components of the refrigeration system, such as various solenoid valves, may also be powered from the electrical system of the vehicle or from the utility power.

In situations where it is desirable to provide multiple different refrigerated environments, a vehicle may be configured with multiple cold boxes. In an in-vehicle cooling device having a plurality of cooling boxes, a plurality of flow paths are provided to cool each cooling box. Each flow path is provided with a flow regulating valve to regulate the temperature of each cold box in order to provide different refrigeration environments.

Disclosure of Invention

It is an object of the present invention to solve or at least alleviate problems with the prior art.

According to an aspect, there is provided a refrigeration device comprising:

a compressor comprising a compressor inlet and a compressor outlet;

a condenser downstream of the compressor outlet;

a first valve downstream of the condenser; and

at least one flow path downstream of the first valve, each of the at least one flow path including a flow regulating valve to control a flow of refrigerant into the at least one flow path;

wherein the first valve and the flow regulating valve are normally closed valves, and wherein the refrigeration system further comprises a bleed flow path connected between the first valve and the flow regulating valve, thereby allowing fluid between the first valve and the flow regulating valve to bleed when the first valve and the flow regulating valve are closed.

Optionally, in an embodiment of the refrigeration apparatus, a first end of the bleed flow path is connected between the first valve and the flow regulating valve, and a second end of the bleed flow path is connected between the compressor outlet and the first valve, such as between the compressor outlet and the condenser, between the condenser and the first valve, or on the condenser.

Optionally, in an embodiment of the refrigeration apparatus, a second valve is disposed on the bleed flow path, the second valve allowing fluid to flow only from the first end of the bleed flow path to the second end of the bleed flow path, for example, the second valve is a check valve.

Optionally, in an embodiment of the refrigeration apparatus, the first valve is a solenoid valve that is normally closed when de-energized, and/or the flow regulating valve is a solenoid valve that is normally closed when de-energized, the flow regulating valve regulating the flow of fluid through the flow regulating valve by controlling a duty cycle.

Optionally, in an embodiment of the refrigeration apparatus, the at least one flow path comprises a plurality of flow paths connected in parallel between the first valve and the compressor inlet, each flow path further comprising a throttling device downstream of the flow regulating valve, such as an expansion valve and an evaporator, wherein the throttling device and the evaporator of each flow path are provided in the corresponding chamber.

Optionally, in an embodiment of the refrigeration apparatus, the refrigeration apparatus is an on-board refrigeration apparatus, the chamber is an on-board cold box, and the compressor, the condenser, the bleed flow path, the first valve, and the second valve are located in a refrigeration unit housing, and the first valve and the flow regulating valve are powered by a vehicle electrical system or an external power source.

Optionally, in an embodiment of the refrigeration device, the refrigeration device comprises a flammable refrigerant.

According to another aspect, there is provided a bleed down method for a refrigeration device according to an embodiment, the method comprising: when the first valve and the flow regulating valve are closed, a bleed flow path is passed to allow fluid between the first valve and the flow regulating valve to drain.

Optionally, the method further comprises passing fluid between the first valve and the flow regulating valve between the compressor outlet and the first valve, such as between the compressor outlet and the condenser, between the condenser and the first valve, or to the condenser.

Optionally, the method further comprises providing a one-way valve on the bleed flow path.

The embodiment of the invention effectively discharges the fluid in the closed pipeline and prevents high pressure from being generated.

Drawings

The disclosure of the present invention will become more readily understood with reference to the accompanying drawings. As is readily understood by those skilled in the art: these drawings are for illustrative purposes only and are not intended to constitute a limitation on the scope of the present invention. Moreover, in the drawings, like numerals are used to indicate like parts, and in which:

figure 1 shows a schematic view of a truck carrying a refrigeration unit according to an embodiment of the invention;

FIG. 2 shows a schematic view of a refrigeration device according to an embodiment of the invention; and

fig. 3 shows a schematic view of a refrigeration device according to another embodiment of the invention.

Detailed Description

Referring initially to FIG. 1, one non-limiting embodiment of a vehicle 40 including a refrigeration system is shown. The vehicle may include a locomotive 401 having a cab, an engine, a generator, and the like. The vehicle 40 further includes a frame 402 supported by a plurality of wheels, the frame 402 having the refrigeration unit housing 10, the first cold box 20, the second cold box 30, and the like disposed thereon. The first cold box 20 defines a first chamber therein for storing articles, and similarly, the second cold box 30 defines a second chamber therein for storing articles. For example, the first and second chambers may provide different refrigeration environments to meet different refrigeration requirements. It should be appreciated that in alternative embodiments, the vehicle may include only one cold box or more than two cold boxes, such as three, four, etc.

A refrigeration device according to an embodiment of the invention will be described with continued reference to fig. 2. A refrigeration device according to an embodiment of the present invention includes: a compressor 11, the compressor 11 including a compressor inlet 112 and a compressor outlet 111, the compressor 11 being drivable by a vehicle engine; condenser 12 downstream of compressor outlet 111; a first valve 13 downstream of the condenser 12; and at least one flow path downstream of the first valve 13. Each of the at least one flow paths includes a flow regulating valve (also may be referred to as a liquid valve) to regulate the flow of refrigerant fluid into each flow path. In the illustrated embodiment, the at least one flow path includes two flow paths, a first flow path and a second flow path, connected in parallel between the first valve 13 and the compressor inlet 112. The first flow path includes the first flow rate adjustment valve 21 and the second flow path includes the second flow rate adjustment valve 31. In alternative embodiments, the at least one flow path may comprise only one flow path, or may comprise three or more flow paths in parallel. In the case of a refrigeration system for a vehicle, the

flow regulating valves

21,31 may be used to control the flow of refrigerant into the respective flow paths in order to regulate the amount of cooling provided by each flow path, i.e. the temperature in each chamber. In some embodiments, at least one flow path may further comprise a throttling device, which may be an expansion valve, for example, and an evaporator downstream of the

flow regulating valve

21, 31. In the illustrated embodiment, the first flow path includes a first throttling device 22 and a first evaporator 23, while the second flow path includes a second throttling device 32 and a second evaporator 33. When the refrigeration apparatus is applied to a vehicle as shown in fig. 1, the throttle device and the evaporator of each flow path may be respectively disposed in the corresponding cold boxes, for example, the first expansion valve 22 and the first evaporator 23 of the first flow path may be disposed in the first cold box 20, and the second expansion valve 32 and the second evaporator 33 of the second flow path may be disposed in the second cold box 30. The first valve 13 and the flow

rate adjustment valves

21,31 of the respective flow paths may be, for example, normally closed valves. That is, the valves are normally closed when not energized or subjected to external forces, and open when electrically energized or subjected to external forces. If refrigerant remains in the closed line between the first valve 13 and each of the flow

rate adjustment valves

21,31 when both the first valve 13 and the flow

rate adjustment valves

21,31 are in the closed state, since the refrigerant is substantially liquid refrigerant discharged from the outlet of the condenser, the liquid refrigerant may thermally expand due to a change in ambient temperature when the ambient temperature changes, thereby generating high pressure in the closed line and generating pressure in the line, even causing a rupture of the line, or the like. To avoid this, according to the embodiment of the present invention, a bleed flow path 15 is provided, and the bleed flow path 15 is connected between the first valve 13 and the

flow regulating valves

21,31, thereby allowing the fluid in the closed line between the first valve 13 and the

flow regulating valves

21,31 to be discharged when the first valve 13 and the

flow regulating valves

21,31 are closed (e.g., closed due to an unexpected power outage). In case the refrigeration system is used in a vehicle, the first valve 13 and the

flow regulating valves

21,31 of the respective flow paths may be powered, for example, by the electrical system of the vehicle or by an external power source, such as the mains. The first valve 13 and the

flow regulating valves

21,31 of the respective flow paths may be arranged as normally closed valves for safety reasons. When the refrigerant of the refrigeration system is flammable refrigerant, it is not desirable that flammable refrigerant stays in each flow path when the first valve 13 and the

flow control valves

21 and 31 of each flow path are closed due to the vehicle stopping power supply (e.g., turning off), because flammable refrigerant in each flow path may leak into the closed cold box chamber if the flammable refrigerant exists, thereby causing a closed flammable environment in the cold box chamber, which may cause a safety hazard.

In the embodiment shown in fig. 2, the first end 151 of the bleed flow path 15 is connected between the first valve 13 and the

flow control valves

21,31 and the second end 152 of the bleed flow path 15 is connected between the condenser 12 and the first valve 13, and in alternative embodiments, the second end 152 of the bleed flow path 15 may be connected anywhere between the compressor outlet 111 and the first valve 13, such as between the compressor outlet 111 and the condenser 12 as shown in fig. 3, or directly to the condenser 12. It should be understood that in other embodiments, the second end 152 of the bleed line 15 may be connected to any location suitable for receiving liquid refrigerant, for example, a refrigeration system may have a different configuration than that shown and the bleed flow path 15 may lead to another suitable location of the refrigeration system, or in other embodiments, it is contemplated that the second end 152 of the bleed flow path 15 may be connected to a liquid reservoir for storing liquid refrigerant, or the like.

In some embodiments, a second valve 14 may be provided on the bleed flow path 15, the second valve 14 only allowing fluid flow from the first end 151 of the bleed flow path 15 to the second end 152 of the bleed flow path 15, as indicated by arrow R. In some embodiments, second valve 14 may employ a check valve. In some embodiments, the first valve 13 and the

flow regulating valves

21,31 on each flow path may be solenoid valves that are normally closed when de-energized. In some embodiments, the

flow regulating valves

21,31 regulate the flow of fluid through the

flow regulating valves

21,31 by controlling the duty cycle, for example, in the event that it is desired to achieve 50% of the flow over a period of time, the flow regulating valves may be open for 50% of the total time and remain closed for the other 50% of the total time.

In some embodiments, the compressor 11, the condenser 12, the bleed circuit 15, and the first valve 13 may be located in the refrigeration unit housing 10. In some embodiments, the

flow regulating valves

21,31 may also be disposed in the refrigeration unit housing 10, leading two flow paths to each cold box, alternatively, as shown in fig. 2 and 3, the

flow regulating valves

21,31 may be disposed within the respective cold boxes, respectively. The components of the refrigeration device, in particular the first valve 13 and the

flow regulating valve

21,31 therein, may be powered by the vehicle electrical system or by the mains, whether in the case of a fuel-powered vehicle or an electric vehicle. When the vehicle stops running, for example, the first valve 13 and the

flow regulating valves

21,31 will close automatically due to a power failure, a closed line will be formed therebetween and the liquid fluid therein may expand to generate a high pressure in this section of the closed line, such as when the ambient temperature changes, even resulting in a rupture of the line. The high pressure fluid is released through the bleed flow path 15 in the embodiment of the present invention, thereby avoiding the above. In the case of using the check valve 14, since the check valve 14 is a purely mechanical component, it is not necessary to modify the control logic of the original system, and in addition, no electrical components exist on the bleed flow path 15, and it can work normally in the case of power failure. In addition, embodiments according to the present invention can be implemented with only a simple modification of existing devices. Further, embodiments of the present invention require only modifications to the refrigeration unit 10 without any modifications to the

cold boxes

20,30, and do not affect the existing design of the cold box portions. It should be understood that although in the embodiments only an on-board refrigeration system has been described, the refrigeration system according to the invention is not limited to on-board applications, but may also be applied in other scenarios.

According to another aspect of the present invention, there is provided a bleed down method for a refrigeration device according to an embodiment, the method comprising: when the first valve 13 and the flow

rate adjustment valves

21,22 are closed off, the fluid between the first valve 13 and the flow

rate adjustment valves

21,22 is allowed to be discharged through the bleed flow path. In some embodiments, the method further comprises passing fluid between the first valve 13 and the

flow regulating valves

21,22 to between the compressor outlet 111 and the first valve 13, such as between the compressor outlet 111 and the condenser 12, between the condenser 12 and the first valve 13, or to the condenser 12. In some embodiments, a check valve 14 may be provided on the bleed flow path 15.

The foregoing description of the specific embodiments has been presented only to illustrate the principles of the invention more clearly, and in which various features are shown or described in detail to facilitate an understanding of the principles of the invention. Various modifications or changes to the invention will be readily apparent to those skilled in the art without departing from the scope of the invention. It is to be understood that such modifications and variations are intended to be included within the scope of the present invention.

Claims

1. A refrigeration apparatus, comprising:

a compressor comprising a compressor inlet and a compressor outlet;

a condenser downstream of the compressor outlet;

a first valve downstream of the condenser; and

2. A cold appliance according to claim 1, wherein a first end of the bleed flow path is connected between the first valve and the flow regulating valve and a second end of the bleed flow path is connected between the compressor outlet and the first valve, such as between the compressor outlet and the condenser, between the condenser and the first valve or on the condenser.

3. A cold appliance according to claim 2, wherein the bleed flow path is provided with a second valve which only allows fluid flow from the first end of the bleed flow path to the second end of the bleed flow path, such as a check valve.

4. The refrigeration unit of claim 1 wherein the first valve is a solenoid valve that is normally closed when de-energized and/or the flow regulating valve is a solenoid valve that is normally closed when de-energized, the flow regulating valve regulating the flow of fluid through the flow regulating valve by controlling a duty cycle.

5. A cold appliance according to claim 1, wherein the at least one flow path comprises a plurality of flow paths connected in parallel between the first valve and the compressor inlet, each flow path further comprising a throttling device, such as an expansion valve, and an evaporator downstream of the flow regulating valve, wherein the throttling device and the evaporator of each flow path are provided in a corresponding chamber.

6. A refrigeration unit as recited in claim 5 wherein said refrigeration unit is an on-board refrigeration unit, said chamber is an on-board refrigeration case and said compressor, said condenser, said bleed flow path, said first valve and said second valve are located in a refrigeration unit housing, said first valve and said flow control valve being powered by a vehicle electrical system or by an external power source.

7. A refrigeration device as recited in claim 1 wherein said refrigeration device comprises a flammable refrigerant.

8. A tapping method for a refrigeration unit as set forth in claim 1, characterized in that the method comprises: when the first valve and the flow regulating valve are closed, a bleed flow path is passed to allow fluid between the first valve and the flow regulating valve to bleed.

9. The method of claim 8, further comprising passing fluid between the first valve and the flow regulating valve between the compressor outlet and the first valve, such as between the compressor outlet and the condenser, between the condenser and the first valve, or to the condenser.

10. The method of claim 9, further comprising providing a one-way valve on the bleed flow path.