EP-4737820-A1 - COOLING SYSTEM WITH DUAL REFRIGERANT CONDENSING ZONES

Abstract

A cooling system and a cooling circuit includes a first refrigerant condensing line including a condenser, a second refrigerant condensing line bypassing the condenser, and a remix chamber disposed in the cooling circuit at a junction of the first and second refrigerant condensing lines. According to a first operating mode of the cooling system, liquid refrigerant is supplied to the remix chamber from the first refrigerant condensing line. According to a second operating mode of the cooling system, liquid refrigerant and vapor refrigerant are supplied to the remix chamber from the respective first and second refrigerant condensing lines and remix in the remix chamber to improve low ambient operation.

Inventors

• COLE, Andrew Nathan

Assignees

• Vertiv Corporation

Dates

Publication Date

20260506

Application Date

20251103

Claims (16)

1. 1. A cooling system comprising: a cooling circuit configured to circulate a refrigerant, the cooling circuit including a first refrigerant condensing line including a condenser, and a second refrigerant condensing line bypassing the condenser; and a remix chamber disposed in the cooling circuit at a junction of the first and second refrigerant condensing lines, wherein in a first operating mode of the cooling system, liquid refrigerant is supplied to the remix chamber from the first refrigerant condensing line, and wherein in a second operating mode of the cooling system, liquid refrigerant and vapor refrigerant are supplied to the remix chamber from the respective first and second refrigerant condensing lines and remix in the remix chamber.
2. 2. The cooling system of claim 1, wherein the second refrigerant condensing line bypasses the condenser.
3. 3. The cooling system of claim 1 or 2, wherein the first operating mode corresponds to a normal ambient temperature operating mode in which ambient temperature is within a predefined ambient temperature range, wherein the second operating mode corresponds to a low ambient temperature operating mode in which ambient temperature is below the predefined ambient temperature range, and wherein refrigerant supplied from the second refrigerant condensing line is at higher pressure and temperature than refrigerant supplied from the first refrigerant condensing line.
4. 4. The cooling system of any one of the preceding claims, further comprising a directional valve disposed in the cooling circuit at a division of the first and second refrigerant condensing lines, the directional valve configured to control refrigerant flow through each of the first and second refrigerant condensing lines.
5. 4. The cooling system of any one of the preceding claims, further comprising a compressor disposed in the cooling circuit upstream of the first and second refrigerant condensing lines.
6. 5. The cooling system of any one of the preceding claims, further comprising at least one pump disposed in the cooling circuit.
7. 6. The cooling system of any one of the preceding claims, further comprising: at least one metering device disposed in the cooling circuit downstream of the remix chamber; and at least one evaporator disposed in the cooling circuit downstream of the at least one metering device.
8. 7. The cooling system of any one of the preceding claims, wherein the first refrigerant condensing line is sub-divided into first and second flow lines entering the remix chamber, each of the first and second flow lines including a flow control valve, wherein the first flow line is open and the second flow line is closed when the cooling system is operating in the first operating mode, and wherein the first flow line is closed and the second flow line is open when the cooling system is operating in the second operating mode.
9. 8. The cooling system of any one of the preceding claims, further comprising: a pump disposed in the first refrigerant condensing line downstream of the condenser; and a bypass flow line disposed in the first refrigerant condensing line bypassing the pump, the bypass flow line including a check valve.
10. 9. The cooling system of any one of the preceding claims, further comprising a controller for operating the cooling system in the first operating mode or the second operating mode depending on ambient temperature.
11. 10. The cooling system of claim 1, further comprising: a compressor disposed in the cooling circuit upstream of the first and second refrigerant condensing lines, the compressor configured to pressurize the refrigerant; a condenser disposed in the first refrigerant condensing line; at least one metering device disposed in the cooling circuit downstream of the remix chamber; and at least one evaporator disposed in the condensing circuit downstream of the at least one metering device.
12. 11. The cooling system of claim 10, wherein the first operating mode corresponds to a normal ambient temperature operating mode in which ambient temperature is within a predefined ambient temperature range, wherein the second operating mode corresponds to a low ambient temperature operating mode in which ambient temperature is below the predefined ambient temperature range, and wherein refrigerant supplied from the second refrigerant condensing line is at higher pressure and temperature than refrigerant supplied from the first refrigerant condensing line.
13. 12. The cooling system of claim 10, further comprising a directional valve disposed in the cooling circuit at a division of the first and second refrigerant condensing lines, the directional valve configured to control refrigerant flow through each of the first and second refrigerant condensing lines.
14. 13. The cooling system of claim 10, further comprising at least one pump disposed in the cooling circuit in the first refrigerant condensing line; or optionally wherein the first refrigerant condensing line is sub-divided into first and second flow lines entering the remix chamber, each of the first and second flow lines including a flow control valve, wherein the first flow line is open and the second flow line is closed when the cooling system is operating in the first operating mode, and wherein the first flow line is closed and the second flow line is open when the cooling system is operating in the second operating mode; or optionally further comprising a controller for operating the cooling system in the first operating mode or the second operating mode depending on ambient temperature.
15. 14. The cooling system of claim 1, further comprising: a condenser disposed in the first refrigerant condensing line; at least one pump disposed in the cooling circuit; at least one metering device disposed in the cooling circuit downstream of the remix chamber; and at least one evaporator disposed in the condensing circuit downstream of the at least one metering device.
16. 15. The cooling system of claim 16, wherein the first operating mode corresponds to a normal ambient temperature operating mode in which ambient temperature is within a predefined ambient temperature range, wherein the second operating mode corresponds to a low ambient temperature operating mode in which ambient temperature is below the predefined ambient temperature range, and wherein refrigerant supplied from the second refrigerant condensing line is at higher pressure and temperature than refrigerant supplied from the first refrigerant condensing line; or optionally further comprising a directional valve disposed in the cooling circuit at a division of the first and second refrigerant condensing lines, the directional valve configured to control refrigerant flow through each of the first and second refrigerant condensing lines; or optionally wherein the first refrigerant condensing line is sub-divided into first and second flow lines entering the remix chamber, each of the first and second flow lines including a flow control valve, wherein the first flow line is open and the second flow line is closed when the cooling system is operating in the first operating mode, and wherein the first flow line is closed and the second flow line is open when the cooling system is operating in the second operating mode; or optionally further comprising a controller for operating the cooling system in the first operating mode or the second operating mode depending on ambient temperature.

Description

CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit of priority of U.S. Application Number 63,716,071 filed November 4, 2024. TECHNICAL FIELD The present disclosure relates generally to refrigerant based cooling systems for data centers and the like, and more particularly, to a cooling system including dual pressure zones for precise ambient temperature control. BACKGROUND Traditional refrigerant based cooling systems operate by repeatedly pressurizing and depressurizing a refrigerant to reject and absorb heat. In a traditional cooling circuit, refrigerant is pressurized in a compressor, rejects heat in a condenser, is depressurized by a metering agent, and absorbs heat in an evaporator. Cooling systems that utilize a cooling circuit can be used to transfer heat from one location to another. For example, in a data center, a cooling circuit can be used to cool electronic equipment by transferring heat from inside a building to outside a building, from one space to another, etc. Cooling system performance depends on the relatedness of pressure, volume, and temperature. As such, optimal cooling system performance requires precise pressure and temperature control. In outside environments where ambient temperature may be low and in some cases below freezing, it becomes necessary to control supply temperature to within a target range to ensure good evaporator performance. Controlling supply temperature during low ambient conditions becomes exceedingly difficult in large component and large capacity cooling systems. Therefore, what is needed is a cooling system with precise ambient temperature control. SUMMARY According to one aspect, the present disclosure is directed to a cooling system including a cooling circuit configured to circulate a refrigerant. In examples, the cooling circuit includes a first refrigerant condensing line including a condenser, a second refrigerant condensing line bypassing the condenser, and a remix chamber disposed in the cooling circuit at a junction of the first and second refrigerant condensing lines. In a first operating mode of the cooling system, liquid refrigerant is supplied to the remix chamber from the first refrigerant condensing line. In a second operating mode of the cooling system, liquid refrigerant and vapor refrigerant are supplied to the remix chamber from the respective first and second refrigerant condensing lines and remix in the remix chamber to increase pressure/temperature of liquid refrigerant supplied to at least one evaporator. In some examples, the first operating mode corresponds to a normal ambient temperature operating mode in which ambient temperature is within a predefined ambient temperature range, the second operating mode corresponds to a low ambient temperature operating mode in which ambient temperature is below the predefined ambient temperature range, and refrigerant supplied from the second refrigerant condensing line is at higher pressure and temperature than refrigerant supplied from the first refrigerant condensing line. In some examples, the cooling system further includes a directional valve (e.g., 3-way valve) disposed in the cooling circuit at a division of the first and second refrigerant condensing lines, the directional valve configured to control refrigerant flow through each of the first and second refrigerant condensing lines. In some examples, the cooling system further includes a compressor disposed in the cooling circuit upstream of the first and second refrigerant condensing lines, the compressor configured to pressurize the refrigerant. In some examples, the cooling system further includes at least one pump disposed in the cooling circuit. In some examples, the cooling system further includes at least one metering device disposed in the cooling circuit downstream of the remix chamber, and at least one evaporator disposed in the cooling circuit downstream of the at least one metering device. In some examples, the first refrigerant condensing line is sub-divided into first and second flow lines entering the remix chamber wherein each of the first and second flow lines includes a flow control valve, the first flow line is open and the second flow line is closed when the cooling system is operating in the first operating mode, and the first flow line is closed and the second flow line is open when the cooling system is operating in the second operating mode. In some examples, the cooling system further includes a pump disposed in the first refrigerant condensing line downstream of the condenser, and a bypass flow line disposed in the first refrigerant condensing line bypassing the pump, the bypass flow line including a check valve. In some examples, the cooling system further includes a controller for operating the cooling system in the first operating mode or the second operating mode depending on ambient temperature. According to another aspect, the present disclosure is directed to a cooling system includin