US-12623512-B2 - Transport refrigeration system with a thermal management system

US12623512B2US 12623512 B2US12623512 B2US 12623512B2US-12623512-B2

Abstract

A transport refrigeration system comprises a refrigeration circuit and a thermal management system. The refrigeration circuit comprises a compressor, a high pressure side heat exchanger on a high pressure side of the compressor, and a low pressure side heat exchanger on a low pressure side of the compressor. The thermal management system comprises a high pressure side fluid circuit comprising a first pump circulating a working fluid, and a first component heat exchanger for heating and/or cooling a first electronic component. The thermal management system also comprises a low pressure side fluid circuit comprising a second pump circulating a working fluid, and a second component heat exchanger for cooling a second electronic component. The high pressure side fluid circuit is in a heat exchange relationship with the refrigeration circuit, and the low pressure side fluid circuit is in a heat exchange relationship with the refrigeration circuit.

Inventors

Lucas Chapeau

Assignees

CARRIER CORPORATION

Dates

Publication Date: 20260512
Application Date: 20230728
Priority Date: 20220729

Claims (20)

1 . A transport refrigeration system comprising: a refrigeration circuit comprising a compressor for compressing a refrigerant, a high pressure side heat exchanger arranged on a high pressure side of the compressor for removing heat from the refrigerant, and a low pressure side heat exchanger arranged on a low pressure side of the compressor for heating the refrigerant; and a thermal management system comprising: a high pressure side fluid circuit comprising a first pump for circulating a working fluid around the high pressure side fluid circuit, and a first component heat exchanger for heating and/or cooling a first electronic component, wherein the high pressure side fluid circuit is arranged in a heat exchange relationship with the refrigeration circuit via the high pressure side heat exchanger for heating the working fluid within the high pressure side fluid circuit; a low pressure side fluid circuit comprising a second pump for circulating the working fluid around the low pressure side fluid circuit, and a second component heat exchanger for cooling a second electronic component via convection, wherein the low pressure side fluid circuit is arranged in a heat exchange relationship with the refrigeration circuit via the low pressure side heat exchanger for cooling the working fluid within the low pressure side fluid circuit; and a pressure compensation system comprising an expansion tank configured to absorb excess pressure in the thermal management system resulting from thermal expansion of the working fluid.
2 . The transport refrigeration system of claim 1 , wherein the thermal management system further comprises: connection piping for fluidly connecting the high pressure side and low pressure side fluid circuits; and a controllable valve assembly arranged to selectively allow the working fluid to pass between the high pressure side and low pressure side fluid circuits via the connection piping, wherein the controllable valve assembly is configured to selectively switch between a first configuration in which the working fluid is prevented from passing between the high pressure side and low pressure side fluid circuits via the connection piping, and a second configuration in which the working fluid is able to pass from the low pressure side fluid circuit to the first component heat exchanger via the connection piping.
3 . The transport refrigeration system of claim 2 , wherein the connection piping and the controllable valve assembly are arranged such that, in the second configuration, the working fluid from the low pressure side fluid circuit is prevented from passing to the first pump and the high pressure side heat exchanger.
4 . The transport refrigeration system of claim 1 , wherein the refrigeration circuit further comprises: a heat rejecting heat exchanger arranged on the high pressure side of the compressor for removing heat from a high pressure refrigerant output by the compressor; an expansion device arranged downstream of the heat rejecting heat exchanger for reducing the pressure of a cooled refrigerant output by the heat rejecting heat exchanger, wherein the expansion device is a valve; and a heat absorbing heat exchanger arranged downstream of the expansion device for heating a low pressure refrigerant output by the expansion device.
5 . The transport refrigeration system of claim 4 , wherein the high pressure side heat exchanger is arranged upstream of the heat rejecting heat exchanger.
6 . The transport refrigeration system of claim 4 , wherein the low pressure side heat exchanger is arranged downstream of the heat absorbing heat exchanger.
7 . The transport refrigeration system of claim 4 , wherein the refrigeration circuit further comprises: a bypass line arranged to direct the refrigerant output by the heat rejecting heat exchanger to the low pressure side of the compressor downstream of the heat absorbing heat exchanger, thereby providing a flow path for the refrigerant to bypass the expansion device and the heat absorbing heat exchanger, wherein the bypass line comprises a flow control valve for controlling the flow rate and pressure of the refrigerant in the bypass line, and wherein the low pressure side heat exchanger is arranged in the bypass line downstream of the flow control valve.
8 . The transport refrigeration system of claim 1 , further comprising a power source for providing electrical power to the transport refrigeration system, wherein the first component heat exchanger is arranged for heating and/or cooling the power source, and wherein the power source is a battery system.
9 . The transport refrigeration system of claim 2 , further comprising a control system for obtaining temperature data and controlling operation of the transport refrigeration system, wherein the control system is configured to: operate the first pump if a temperature of the first electronic component is less than a first threshold temperature; and/or operate the second pump if a temperature of the second electronic component exceeds a second threshold temperature.
10 . The transport refrigeration system of claim 9 , wherein the control system is further configured to: operate the controllable valve assembly in the first configuration if a temperature of the first electronic component is less than or equal to a third threshold temperature that is higher than the first threshold temperature; and/or operate the controllable valve assembly in the second configuration and operate the second pump if a temperature of the first electronic component exceeds a third threshold temperature that is higher than the first threshold temperature.
11 . The transport refrigeration system of claim 10 , wherein: the first threshold temperature is between at least one of −20° C. and 20° C., and between 0° C. and 10° C.; and/or the second threshold temperature is between at least one of 50° C. and 90° C., and between 70° C. and 80° C.; and/or the third threshold temperature is between at least one of 20° C. and 50° C., and between 30° C. and 40° C.
12 . The transport refrigeration system of claim 1 , wherein the thermal management system further comprises a radiator in fluid communication with the low pressure side fluid circuit for cooling the working fluid within the low pressure side fluid circuit, and wherein the radiator is fluidly connected to the low pressure side fluid circuit via a low pressure side radiator valve arranged to selectively allow the working fluid to pass between the low pressure side fluid circuit and the radiator.
13 . A method of controlling the temperature of electronic components using the transport refrigeration system of claim 1 , wherein the first component heat exchanger is arranged for heating and/or cooling a first electronic component, and the second component heat exchanger is arranged for cooling a second electronic component, the method comprising: determining a temperature of the first electronic component; determining a temperature of the second electronic component; operating the first pump to circulate working fluid around the high pressure side fluid circuit if the temperature of the first electronic component is less than a first threshold temperature; and/or operating the second pump to circulate working fluid around the low pressure side fluid circuit if the temperature of the second electronic component exceeds a second threshold temperature.
14 . The method of claim 13 , wherein when the low pressure side heat exchanger is arranged in a bypass line of the refrigeration circuit, the method comprises: opening a flow control valve to allow the refrigerant to flow through the bypass line if the temperature of the second electronic component exceeds the second threshold temperature and/or if the temperature of the first electronic component exceeds a third threshold temperature that is higher than the first threshold temperature.
15 . The method of claim 13 , further comprising: operating a controllable valve assembly in a first configuration if the temperature of the first electronic component is less than or equal to a third threshold temperature that is higher than the first threshold temperature; and/or operating the controllable valve assembly in a second configuration and operating the second pump if the temperature of the first electronic component exceeds a third threshold temperature that is higher than the first threshold temperature.
16 . The transport refrigeration system of claim 1 , wherein the thermal management system further comprises: a radiator fluidly connected to at least one of the high pressure side fluid circuit and the low pressure side fluid circuit; and a control system configured to operate one or more radiator valves to allow or restrict flow of the working fluid through the radiator based on a comparison between an ambient air temperature and a temperature of the first electronic component or a temperature of the second electronic component.
17 . The transport refrigeration system of claim 1 , wherein the expansion tank is fluidly connected to both the high pressure side fluid circuit and the low pressure side fluid circuit via a conduit.
18 . The transport refrigeration system of claim 16 , wherein the control system is further configured to activate an electric heater for heating the first electronic component if the temperature of the first electronic component remains below a threshold after a predefined time of pump operation.
19 . The transport refrigeration system of claim 1 , wherein the second component heat exchanger is arranged in a second airflow path driven by a second fan, and wherein the second fan is arranged to drive or draw air over the second component heat exchanger and the second electronic component.
20 . The transport refrigeration system of claim 1 , wherein the first component heat exchanger is arranged in a first linear airflow path driven by a first fan such that the first fan is arranged to drive or draw air over the first component heat exchanger and the first electronic component for heating and/or cooling the first electronic component by convection.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to EP Patent Application No. 22187958.8 filed on Jul. 29, 2022, which is incorporated by reference herein in its entirety. BACKGROUND The invention relates to a transport refrigeration system, and more particularly to a transport refrigeration system having a thermal management system for controlling the temperature of electronic components of the transport refrigeration system. Typically, transport refrigeration systems include a refrigeration circuit that is utilised to control the temperature of an enclosed compartment in order to ensure there is no damage or spoilage to temperature-sensitive cargo. At various stages during the refrigeration cycle in the refrigeration circuit, heat is absorbed or lost by a refrigerant flowing through the system. In conventional transport refrigeration systems, the temperatures of electronic components need to be tightly controlled in order for the system to operate effectively (if at all). This can be of particular importance in electric refrigeration systems which use batteries to provide electrical power to the refrigeration system, since it may be necessary to maintain the batteries within a temperature range suitable for operation. For instance, in some conventional battery modules the batteries are unable to charge when their internal cell temperature falls below a certain temperature (e.g. below 0° C.) and are unable to provide power at all (discharge) once their internal cell temperature falls below an even lower temperature (e.g. below −10° C.). At high temperatures, the batteries may stop working or become damaged. The specific operational temperature range of a battery depends on the type of battery, and its chemistry. For instance, it is generally desired to maintain lithium iron phosphate (LFP) battery cells within a temperature range of between 5° C. and 35° C. It may also be necessary to keep other electronic components of the refrigeration system, such as power electronic modules (e.g. power semiconductor device assemblies), cool to avoid overheating and/or damaging the components. SUMMARY According to a first aspect of the invention, there is provided a transport refrigeration system comprising: a refrigeration circuit comprising a compressor for compressing a refrigerant, a high pressure side heat exchanger arranged on a high pressure side of the compressor for removing heat from the refrigerant, and a low pressure side heat exchanger arranged on a low pressure side of the compressor for heating the refrigerant; and a thermal management system comprising: a high pressure side fluid circuit comprising a first pump for circulating a working fluid around the high pressure side fluid circuit, and a first component heat exchanger for heating and/or cooling a first electronic component, wherein the high pressure side fluid circuit is arranged in a heat exchange relationship with the refrigeration circuit via the high pressure side heat exchanger for heating the working fluid within the high pressure side fluid circuit; and a low pressure side fluid circuit comprising a second pump for circulating a working fluid around the low pressure side fluid circuit, and a second component heat exchanger for cooling (and/or heating) a second electronic component, wherein the low pressure side fluid circuit is arranged in a heat exchange relationship with the refrigeration circuit via the low pressure side heat exchanger for cooling the working fluid within the low pressure side fluid circuit. BRIEF DESCRIPTION OF THE FIGURES Certain preferred embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which: FIG. 1 is a schematic diagram of a refrigerated cargo vehicle having a transport refrigeration system; FIG. 2 is a schematic diagram of a refrigeration circuit of a transport refrigeration system having a thermal management system; FIG. 3 is a schematic diagram of a thermal management system of a transport refrigeration system; FIG. 4 is a schematic diagram of an alternative thermal management system of a transport refrigeration system; FIG. 5 is a schematic diagram of an alternative refrigeration circuit of a transport refrigeration system having a thermal management system; and FIG. 6 shows the thermal management system of FIG. 3 in a cooling mode of operation. DETAILED DESCRIPTION The temperature of the refrigerant in the refrigeration circuit of the transport refrigeration system will be different at different points as it circulates around the refrigeration circuit. Advantageously, with the present invention the temperature of the refrigerant can be utilised by the thermal management system to control the temperature of electronic components. For instance, in a situation where a first electronic component is too cold, the first pump can be operated to circulate a working fluid around the high pressure side fluid circuit. As