Low energy consumption refrigeration system with a rotary pressure exchanger replacing the bulk flow compressor and the high pressure expansion valve

Patent metadata

Field	Value
Publication number	US-2022011023-A1
Application number	US-202016926368-A
Country	US
Kind code	A1
Filing date	Jul 10, 2020
Priority date	Jul 10, 2020
Publication date	Jan 13, 2022
Grant date	—

Abstract

A refrigeration system includes a rotary pressure exchanger fluidly coupled to a low pressure loop and a high pressure loop. The rotary pressure exchanger replaces a traditional bulk flow compressor. The rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure loop, to receive the refrigerant at low pressure from the low pressure loop, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger includes the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger includes the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor.

First claim

1 . A refrigeration system comprising:
a high pressure loop for circulating a refrigerant at a high pressure through it; a gas cooler or a condenser disposed along the high pressure loop, wherein the high pressure loop is configured to reject heat to the surroundings from the refrigerant at high pressure via the gas cooler or the condenser, and the refrigerant at high pressure is in a supercritical state or subcritical state; a second low pressure loop for circulating the refrigerant at a low pressure through it; an evaporator disposed along the low pressure loop, wherein the low pressure loop is configured to absorb heat from the surroundings into the refrigerant at low pressure via the evaporator, and the refrigerant at low pressure is in a liquid state, a vapor state, or a two-phase mixture of liquid and vapor; a rotary pressure exchanger fluidly coupled to the low pressure loop and the high pressure loop, wherein the rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure loop, to receive the refrigerant at low pressure from the low pressure loop, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger comprises the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger comprises the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor; and a high differential pressure (DP), low flow multi-phase leakage pump disposed between the low pressure loop and the high pressure loop, wherein the high DP, low flow multi-phase leakage pump is configured to pressurize leakage flow exiting a low pressure outlet of the rotary pressure exchanger and to pump the leakage flow back into high pressure loop via a high pressure inlet of the rotary pressure exchanger, and wherein the high DP, low flow multi-phase leakage pump is configured to pump the refrigerant in the liquid state, the supercritical state, or in the two-phase mixture of liquid and vapor.

2 . The refrigeration system of claim 1 , comprising a high pressure, low DP multi-phase circulation pump disposed downstream of the gas cooler or the condenser in the high pressure loop, wherein the high pressure, low DP multi-phase circulation pump is configured to pump the refrigerant in the liquid state or the two-phase mixture of liquid and vapor.

3 . The refrigeration system of claim 2 , comprising a low pressure, low DP multi-phase circulation pump disposed upstream of the evaporator in the low pressure loop, wherein the low pressure, low DP multi-phase circulation pump is configure to pump the refrigerant in the liquid state or the two-phase mixture of liquid and vapor.

4 . The refrigeration system of claim 3 , comprising a first three-way valve disposed between the rotary pressure exchanger and the low pressure, low DP multi-phase circulation pump in the low pressure loop.

5 . The refrigeration system of claim 4 , comprising a second three-way valve disposed between the rotary pressure exchanger and the high pressure, low DP multi-phase circulation pump in the high pressure loop.

6 . The refrigeration system of claim 5 , wherein the high DP, low flow multi-phase leakage pump is disposed between the first three-way valve and the second three-way valve.

7 . The refrigeration system of claim 1 , wherein the refrigerant comprises carbon dioxide.

8 . A refrigeration system comprising:
a high pressure loop for circulating a refrigerant at a high pressure through it; a gas cooler or a condenser disposed along the high pressure loop, wherein the high pressure loop is configured to reject heat to the surroundings from the refrigerant at high pressure via the gas cooler or the condenser, and the refrigerant at high pressure is in a supercritical state or subcritical state; a second low pressure loop for circulating the refrigerant at a low pressure through it; an evaporator disposed along the low pressure loop, wherein the low pressure loop is configured to absorb heat from the surroundings into the refrigerant at low pressure via the evaporator, and the refrigerant at low pressure is in a liquid state, a vapor state, or a two-phase mixture of liquid and vapor; a rotary pressure exchanger fluidly coupled to the low pressure loop and the high pressure loop, wherein the rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure loop, to receive the refrigerant at low pressure from the low pressure loop, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger comprises the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger comprises the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor; and a high differential pressure (DP), low flow leakage compressor disposed between the low pressure loop and the high pressure loop, wherein the high DP, low flow leakage compressor is configured to pressurize leakage flow exiting a low pressure outlet of the rotary pressure exchanger and to compress the leakage flow back into high pressure loop at a location both downstream of a high pressure outlet of the rotary pressure exchanger and upstream of the gas cooler/condenser, and wherein the high DP, low flow leakage compressor is configured to compress the refrigerant from a low pressure vapor state to a high pressure vapor state.

9 . The refrigeration system of claim 8 , comprising a high pressure, low DP multi-phase circulation pump disposed downstream of the gas cooler or the condenser in the high pressure loop, wherein the high pressure, low DP multi-phase circulation pump is configured to pump the refrigerant in the liquid state or the two-phase mixture of liquid and vapor.

10 . The refrigeration system of claim 9 , comprising a low pressure, low DP multi-phase circulation pump disposed upstream of the evaporator in the low pressure loop, wherein the low pressure, low DP multi-phase circulation pump is configure to pump the refrigerant in the liquid state or the two-phase mixture of liquid and vapor.

11 . The refrigeration system of claim 10 , comprising a first three-way valve disposed between the evaporator and the rotary pressure exchanger in the low pressure loop, wherein, during operation of the refrigeration system, a portion of a flow exiting the evaporator is diverted through the first three-way valve to an inlet of the high DP, low flow leakage compressor and a remaining portion of the flow exiting the evaporator proceeds to a low pressure inlet of the rotary pressure exchanger.

12 . The refrigeration system of claim 11 , comprising a second three-way valve disposed between the rotary pressure exchanger and the gas cooler or the condenser in the high pressure loop, wherein, during operation of the refrigeration system, a first flow exiting from the high DP, low flow leakage compressor combines with a second flow exiting from the high pressure outlet of the rotary pressure exchanger prior to flowing to an inlet of the gas cooler or the condenser.

13 . The refrigeration system of claim 12 , wherein the high DP, low flow multi-phase leakage pump is disposed between the first three-way valve and the second three-way valve.

14 . The refrigeration system of claim 8 , wherein the refrigerant comprises carbon dioxide.

Assignees

• Energy Recovery Inc

Inventors

• Thatte Azam Mihir
• Pattom Matthew Joseph

Classifications

• F25B1/04

  with compressor of rotary type ({F25B1/005,} F25B1/10 take precedence) · CPC title

• F25B9/008 Primary

  the refrigerant being carbon dioxide · CPC title

• F25B40/00

  Subcoolers, desuperheaters or superheaters · CPC title

• F25B2309/02

  using the Joule-Thompson effect · CPC title

• F25B41/30

  Expansion means; Dispositions thereof · CPC title