Transport refrigeration system

Patent metadata

Field	Value
Publication number	US-10612820-B2
Application number	US-201616068182-A
Country	US
Kind code	B2
Filing date	Dec 6, 2016
Priority date	Jan 8, 2016
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

A transport refrigeration system is configured to set a first path, a second path, a third path, and fourth path selectively. The first path connects compressors in series. In the first path, interior heat exchangers each serve as an evaporator. The second path connects the compressors in series. In the second path, the interior heat exchangers each serve as a condenser. The third path connects the compressors in parallel. In the third path, at least one of the interior heat exchangers serve as the evaporator and the rest of the interior heat exchangers serve as the condenser. The fourth path connects the compressors in parallel. In the fourth path, the interior heat exchangers each serve as the condenser.

First claim

What is claimed is:

1. A transport refrigeration system that is mounted to a vehicle including a container divided into a plurality of chambers, the transport refrigeration system comprising:
a plurality of interior heat exchangers, including a first interior heat exchanger and a second interior heat exchanger, that are positioned in the plurality of chambers respectively and are configured to perform heat exchanges between a refrigerant and air in the plurality of chambers;
an exterior heat exchanger that is configured to perform a heat exchange between the refrigerant and an outside air;
a plurality of compressors, including a first compressor and a second compressor, that are configured to discharge the refrigerant and that are configured to allow the refrigerant to circulate between the plurality of interior heat exchangers and the exterior heat exchanger;
a plurality of switching valves that are configured to set paths selectively, the paths allowing the refrigerant, which is discharged from the plurality of compressors, to flow therethrough;
an exterior expansion valve that is configured to reduce a flow rate of the refrigerant flowing therethrough;
an exterior bypass passage that is connectable to the passage and allows the refrigerant to flow therethrough while bypassing the exterior expansion valve;
an exterior switching valve that is configured to open and close the exterior bypass passage;
an interior expansion valve that is configured to reduce a flow rate of the refrigerant flowing therethrough;
an interior bypass passage that is connectable to the passage and allows the refrigerant to flow therethrough while bypassing the interior expansion valve; and
an interior switching valve that is configured to open and close the interior bypass passage, wherein
a group of the interior expansion valve, the interior bypass passage, and the interior switching valve is provided to each of the plurality of interior heat exchangers,
the paths include
a first path that connects the plurality of compressors in series, the first path in which each of the plurality of interior heat exchangers serves as an evaporator,
a second path that connects the plurality of compressors in series, the second path in which each of the plurality of interior heat exchangers serves as a condenser,
a third path that connects the plurality of compressors in parallel, the third path in which at least one of the plurality of interior heat exchangers serve as the evaporator and the rest of the plurality of interior heat exchangers serve as the condenser, and
a fourth path that connects the plurality of compressors in parallel, the fourth path in which the plurality of interior heat exchangers each serve as the condenser,
in the first path,
the exterior expansion valve is positioned in a passage that connects an outlet of the exterior heat exchanger to inlets of the plurality of interior heat exchangers and
the interior expansion valve is positioned in the passage downstream of the exterior expansion valve, and

in the third path,
the refrigerant, which flows out of the first compressor, flows through the exterior heat exchanger, the exterior bypass passage, the interior expansion valve corresponding to the first interior heat exchanger, and the first interior heat exchanger in this order and
the refrigerant, which flows out of the second compressor, flows through the second interior heat exchanger, the interior bypass passage corresponding to the second interior heat exchanger, the interior expansion valve corresponding to the first interior heat exchanger, and the first interior heat exchanger in this order.

2. The transport refrigeration system according to claim 1 , the transport refrigeration system further comprising
a switching valve that is mounted to a passage connecting an outlet of the second compressor to an inlet of the second interior heat exchanger in the third path, wherein
the switching valve is configured to prevent the refrigerant, which flows out of the first compressor, from flowing toward the second compressor in the second path.

3. The transport refrigeration system according to claim 1 , the transport refrigeration system further comprising
a switching valve that is mounted to a passage, which connects an outlet of the first compressor to an inlet of the second interior heat exchanger in the second path, the passage allowing the refrigerant, flowing through the first and second compressors, to flow therethrough from the outlet of the first compressor to the second interior heat exchanger in the second path, wherein
when the third path is set,
the switching valve is closed and
the refrigerant flowing out of the second compressor flows into a junction in a passage connecting the switching valve and the second interior heat exchanger.

4. The transport refrigeration system according to claim 1 , the transport refrigeration system further comprising
a liquid reservoir that stores a part of the refrigerant, which circulates in the transport refrigeration system, in a liquid state, the liquid reservoir being mounted to a passage connecting the exterior expansion valve and the interior expansion valve to each other, wherein
the liquid reservoir discharges only a liquid refrigerant both in a case of discharging the refrigerant stored therein toward the exterior expansion valve and in a case of discharging the refrigerant stored therein toward the interior expansion valve.

5. The transport refrigeration system according to claim 1 , the transport refrigeration system further comprising
a controller that is configured to set the first path, the second path, the third path, and the fourth path selectively.

6. The transport refrigeration system according to claim 5 , wherein
the plurality of chambers include a first chamber and a second chamber, and
the controller sets the first path when a temperature in the first chamber is higher than a first temperature and a temperature in the second chamber is higher than a second temperature.

7. The transport refrigeration system according to claim 5 , wherein
the plurality of chambers include a first chamber and a second chamber, and
the controller sets the third path when a temperature in the first chamber is higher than a first temperature and a temperature in the second chamber is lower than a second temperature.

8. The transport refrigeration system according to claim 5 , wherein
the plurality of chambers include a first chamber and a second chamber, and
the controller sets the second or fourth path when a temperature in the first chamber is lower than a first temperature and a temperature in the second chamber is lower than a second temperature.

9. The transport refrigeration system according to claim 8 , wherein
the controller sets the fourth path when a temperature difference between the temperature in the first chamber and the first temperature is a first threshold value or greater or when a temperature difference between the temperature in the second chamber and the second temperature is a second threshold value or greater, and
the controller otherwise sets the second path.

Assignees

• Denso Corp

Inventors

• Takizawa Ryo

Classifications

• B60H1/00907

  where the flow direction of the refrigerant changes and an evaporator becomes condenser · CPC title

• B60H1/3232

  particularly adapted for load transporting vehicles (B60H1/3226 takes precedence) · CPC title

• F25B2313/0314

  Temperature sensors near the indoor heat exchanger · CPC title

• F25B1/10

  with multi-stage compression (with cascade operation F25B7/00) · CPC title

• F25B2313/0232

  with bypasses · CPC title