Refrigeration system and method of operating a refrigeration system

Patent metadata

Field	Value
Publication number	US-12504209-B2
Application number	US-202418408791-A
Country	US
Kind code	B2
Filing date	Jan 10, 2024
Priority date	Jan 10, 2023
Publication date	Dec 23, 2025
Grant date	Dec 23, 2025

Abstract

A refrigeration system comprising a controller is provided. The controller is configured to: determine one or more parameters of the refrigeration system; determine whether a first mode selection condition has been met and/or whether a second mode selection condition has been met based on the determined one or more parameters; select a first mode upon the first mode selection condition having been determined to have been met and/or upon the second mode selection condition having been determined to have not been met; select a second mode upon the second mode selection condition having been determined to have been met and/or upon the first mode selection condition having been determined to have not been met; and operate the refrigeration system in the selected mode.

First claim

The invention claimed is:

1 . A refrigeration system, the refrigeration system comprising:
a compressor; a condenser; an expansion valve; an evaporator; a liquid-suction heat exchanger; a suction line configured to convey a refrigerant from the evaporator to the compressor via the liquid-suction heat exchanger; a discharge line configured to convey the refrigerant from the compressor to the condenser; an upstream suction line temperature sensor configured to sense a temperature of the refrigerant in the suction line upstream of the liquid-suction heat exchanger; an upstream suction line pressure sensor configured to sense a pressure of the refrigerant in the suction line upstream of the liquid-suction heat exchanger; a downstream suction line temperature sensor configured to sense a temperature of the refrigerant in the suction line downstream of the liquid-suction heat exchanger; a downstream suction line pressure sensor configured to sense a pressure of the refrigerant in the suction line downstream of the liquid-suction heat exchanger; and a controller, wherein the controller is configured to:
determine one or more parameters of the refrigeration system;
determine whether a first mode selection condition has been met and/or whether a second mode selection condition has been met based on the determined one or more parameters;
select a first mode upon the first mode selection condition having been determined to have been met and/or upon the second mode selection condition having been determined to have not been met;
select a second mode upon the second mode selection condition having been determined to have been met and/or upon the first mode selection condition having been determined to have not been met; and
operate the refrigeration system in the selected mode,
wherein operating the refrigeration system in the first mode comprises controlling the expansion valve to bring a superheat of the refrigerant in the suction line upstream of the liquid-suction heat exchanger towards a first target superheat value or towards or within a first target range of superheat values, wherein the superheat of the refrigerant in the suction line upstream of the liquid-suction heat exchanger is determined based on the sensed temperature and pressure of the refrigerant in the suction line upstream of the liquid-suction heat exchanger, and
wherein operating the refrigeration system in the second mode comprises controlling the expansion valve to bring a superheat of the refrigerant in the suction line downstream of the liquid-suction heat exchanger towards a second target superheat value or towards or within a second target range of superheat values, wherein the superheat of the refrigerant in the suction line downstream of the liquid-suction heat exchanger is determined based on the sensed temperature and pressure of the refrigerant in the suction line downstream of the liquid-suction heat exchanger.

2 . The refrigeration system of claim 1 , wherein the controller is configured to:
select the first mode upon the first mode selection condition having been determined to have been met or upon the second mode selection condition having been determined to have not been met; and select the second mode upon the second mode selection condition having been determined to have been met or upon the first mode selection condition having been determined to have not been met.

3 . The refrigeration system of claim 1 , wherein the controller is configured to:
determine whether the first mode selection condition has been met and whether the second mode selection condition has been met; select the first mode upon the first mode selection condition having been determined to have been met; select the second mode upon the second mode selection condition having been determined to have been met; and upon determining that neither the first mode selection condition nor the second mode selection condition have been met, select the first mode if the refrigeration system is currently operating in the first mode and select the second mode if the refrigeration system is currently operating in the second mode.

4 . The refrigeration system of claim 1 , wherein the controller is configured to:
determine whether the first mode selection condition has been met and whether the second mode selection condition has been met; select the first mode upon the first mode selection condition having been determined to have been met; select the second mode upon the second mode selection condition having been determined to have been met; and upon determining that neither the first mode selection condition nor the second mode selection condition have been met, select the second mode.

5 . The refrigeration system of claim 1 , wherein the controller is configured to:
determine whether the first mode selection condition has been met and whether a second mode selection condition has been met; select the first mode upon the first mode selection condition having been determined to have been met; select the second mode upon the second mode selection condition having been determined to have been met; and upon determining that neither the first mode selection condition nor the second mode selection condition have been met, select the first mode.

6 . The refrigeration system of claim 1 , further comprising an accumulator tank configured to remove liquid droplets from the refrigerant within the suction line, wherein the accumulator tank is disposed along the suction line downstream of the downstream suction line pressure and temperature sensors.

7 . The refrigeration system of claim 1 , further comprising:
an additional downstream suction line temperature sensor configured to sense an additional temperature of the refrigerant in the suction line upstream of the downstream suction line pressure and temperature sensors; and an additional downstream suction line pressure sensor configured to sense an additional pressure of the refrigerant in the suction line upstream of the downstream suction line pressure and temperature sensors, wherein the controller is configured to:
determine whether the first mode selection condition has been met and whether the second mode selection condition has been met;
select the first mode upon the first mode selection condition having been determined to have been met;
select the second mode upon the second mode selection condition having been determined to have been met;
upon determining that neither the first mode selection condition nor the second mode selection condition have been met, select a third mode; and
operate the refrigeration system in the selected mode,
wherein operating the refrigeration system in the third mode comprises controlling the expansion valve to bring a superheat of the refrigerant in the suction line upstream of the downstream suction line pressure and temperature sensors towards a third target superheat value or towards or within a third target range of superheat values, wherein the superheat of the refrigerant in the suction line upstream of the downstream suction line pressure and temperature sensors is determined based on the sensed additional temperature and additional pressure of the refrigerant in the suction line upstream of the downstream suction line pressure and temperature sensors.

8 . The refrigeration system of claim 7 , further comprising an accumulator tank configured to remove liquid droplets from the refrigerant within the suction line, wherein the accumulator tank is disposed along the suction line upstream of the downstream suction line pressure and temperature sensors and downstream of the additional downstream suction line pressure and temperature sensors.

9 . The

Assignees

• Thermo King Llc

Inventors

• Donnellan Wayne
• Greene Michael
• Nayak Hebri Gurudath

Classifications

• F25B13/00

  Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) · CPC title

• F25B2700/21175

  of the refrigerant at the outlet of the evaporator · CPC title

• F25B2700/21174

  of the refrigerant at the inlet of the evaporator · CPC title

• F25B6/04

  arranged in series · CPC title

• F25B5/04

  arranged in series · CPC title