# US 2026/0276151 A1 · Cryogenic sub-cooling

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2026/0276151 A1
- Document ID: US20260276151A1
- Status: Published application
- Kind: A1
- Application number: 18/873,818
- Filed: 2023-06-15
- Published: 2026-09-17
- Earliest claimed: 2022-06-16
- Assignees: Universiteit Twente
- Applicants: Universiteit Twente
- Inventors: Srinivas VANAPALLI; Herman Johannes HOLLAND
- Web page: https://patentgrep.com/patent/US20260276151A1

## CPC

- F17C 9/02: with change of state, e.g. vaporisation
- F25B 19/005: {the refrigerant being a liquefied gas}
- F25B 40/02: Subcoolers
- F25B 41/30: Expansion means; Dispositions thereof
- F17C 2223/0161: cryogenic, e.g. LNG, GNL, PLNG
- F17C 2225/0123: gaseous, e.g. CNG, GNC
- F17C 2227/0135: Pumps
- F17C: VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES (storing fluids in natural or artificial cavities or chambers in the earth B65G5/00; construction or assembling of bulk storage containers employing civil-engineering techniques E04H7/00; variable-capacity gas-holders F17B; liquefaction or refrigeration machines, plants, or systems F25)
- F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS

## Abstract

The invention provides a method for subcooling a cryogenic liquid (1), the method comprising providing a discharge element (2) comprising a first discharge element portion (23) comprising (i) a discharge element inlet opening (21), (ii) a throttle element (25), and (iii) a heat conductive wall (28); providing a cryogenic liquid (1) in an open container (10); immersing the first discharge element portion (23) in the cryogenic liquid (1) in the open container (10); and reducing a pressure in the discharge element (20) at a downstream side (26) of the throttle element (25), thereby inducing a flow of the cryogenic liquid (1) from an upstream side (24) of the throttle element (25) through the throttle element (25), wherein at least part of the cryogenic liquid (1) changes phase at the downstream side (26) of the throttle element (25), thereby providing a heat flow from the cryogenic liquid (1) surrounding the discharge element (20) to the first discharge element portion (23).

## Claims

### Claim 1

A method for subcooling a cryogenic liquid (1), wherein the method comprises:
providing a discharge element (2) comprising a first discharge element portion (23) comprising (i) a discharge element inlet opening (21), (ii) a throttle element (25), and (iii) a heat conductive wall (28),
providing a cryogenic liquid (1) in an open container (10),
immersing the first discharge element portion (23) in the cryogenic liquid (1) in the open container (10), and
reducing a pressure in the discharge element (20) at a downstream side (26) of the throttle element (25), thereby inducing a flow of the cryogenic liquid (1) from an upstream side (24) of the throttle element (25) through the throttle element (25), wherein at least part of the cryogenic liquid (1) changes phase at the downstream side (26) of the throttle element (25), thereby providing a heat flow from the cryogenic liquid (1) surrounding the discharge element (20) to the first discharge element portion (23).

### Claim 2 (depends on 1)

The method according to claim 1, wherein the discharge element (2) further comprises a further discharge element portion (29), wherein the method comprises providing the further discharge element portion (29) protruding from the cryogenic liquid (1) in the open container (10), wherein the first discharge element portion (23) is immersed in the cryogenic liquid (1), wherein a pumping device (30) fluidly coupled to the further discharge element portion (29) is applied for reducing the pressure in the discharge element (20) at the downstream side (26) of the throttle element (25).

### Claim 3 (depends on 1)

The method according to claim 1, wherein the method comprises maintaining a pressure of the cryogenic liquid (1) in the open container (10) at atmospheric pressure.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the pressure in the discharge element (20) at the downstream side (26) of the throttle element (25) is reduced to a pressure selected to be below a triple point pressure of the cryogenic liquid (1).

### Claim 5 (depends on 1)

The method according to claim 1, wherein the cryogenic liquid (1) is selected from the group consisting of nitrogen, argon, carbon dioxide, liquified natural gas (LNG), and hydrogen.

### Claim 6 (depends on 1)

The method according to claim 1, comprising using a venturi vacuum system (35) for reducing the pressure in the discharge element (20).

### Claim 7 (depends on 1)

The method according to claim 1, wherein the method further comprises pre-cooling at least the first discharge element portion (23) of the discharge element (20) to a precooling temperature, prior to immersing the first discharge element portion (23) in the cryogenic liquid (1), wherein the precooling temperature is selected to be equal to or lower than 273.15 K.

### Claim 8 (depends on 7)

The method according to claim 7, wherein the precooling temperature is selected to be equal to or lower than a temperature of the cryogenic liquid (1).

### Claim 9

A system (100) for subcooling a cryogenic liquid (1), wherein the system (100) comprises (i) a discharge element (20) comprising a first discharge element portion (23), (ii) a further discharge element portion (29) fluidically connected to the first discharge element portion (23), and (iii) a pumping device (30), wherein the first discharge element portion (23) comprises a discharge element inlet opening (21), a throttle element (25) and a heat conductive wall (28); wherein
the pumping device (30) is fluidically coupled to the further discharge element portion (29) and configured for reducing a pressure in the discharge element (20) at a downstream side (26) of the throttle element (25), for providing the cryogenic liquid (1) to flow from an upstream location (24) of the throttle element (25) through the throttle element (25), wherein at least part of the cryogenic liquid (1) changes phase at the downstream side (26) of the throttle element (25), if the discharge element inlet opening (21) and the first discharge element portion (23) are configured in the cryogenic liquid (1) and the further discharge element portion (29) protrudes from the cryogenic liquid (1).

### Claim 10 (depends on 9)

The system (100) according to claim 9, comprising a container (10) for containing the cryogenic liquid (1), wherein the container (10) is an open container, wherein the container (10) contains the cryogenic liquid (1).

### Claim 11 (depends on 9)

The system (100) according to claim 9, wherein the first discharge element portion (23) comprises one or more heat conductive extensions (22) extending from the heat conductive wall (28) for enhancing exchange of heat between the heat conductive wall (28) and external from the discharge element (20).

### Claim 12 (depends on 9)

The system according to claim 9, wherein the throttle element (25) comprises one or more of a cavity, a porous element, a capillary tube, and a controllable flow restriction and/or wherein the discharge element inlet opening (21) comprises an orifice defining the throttle element (25).

### Claim 13 (depends on 9)

The system (100) according to claim 9, wherein the pumping device (30) comprises a venturi vacuum system (35).

### Claim 14 (depends on 13)

The system (100) according to claim 13, wherein the venturi vacuum system (35) is configured for a gaseous working fluid.

### Claim 15 (depends on 9)

The system (100) according to claim 9, wherein the system further comprises a flare system (40) fluidically coupled a discharge of the discharge element (20).