# US 10,321,609 B2 · Cooling system and method of cooling electronic device

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

- Number: US 10,321,609 B2
- Document ID: US10321609B2
- Status: Granted
- Kind: B2
- Application number: 15/787,757
- Filed: 2017-10-19
- Published: 2018-05-31
- Granted: 2019-06-11
- Earliest claimed: 2016-11-28
- Assignees: Fujitsu Limited
- Applicants: Fujitsu Limited
- Inventors: Keita Hirai; Tsuyoshi So; Naofumi Kosugi
- Web page: https://patentgrep.com/patent/US10321609B2

## CPC

- H05K 7/20781: {within cabinets for removing heat from server blades}
- H05K 7/20236: {by immersion}
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS

## Abstract

A cooling system includes an immersion tank that includes a liquid coolant sealed therein, a housing that includes through-holes formed in a top portion and a bottom portion thereof, respectively, and disposed within the immersion tank, an electronic device disposed in the housing in a state of being immersed in the coolant, a coolant flow path formed between an inner surface of the immersion tank and an outer surface of the housing to couplet he through-hole in the top portion of the housing to the through-hole in the bottom portion of the housing so that the coolant flows therethrough, and a heat transfer member that transports heat of the coolant in the coolant flow path to an outside of the immersion tank.

## Claims

### Claim 1

A cooling system comprising:
an immersion tank that includes a liquid coolant sealed therein;
a housing that includes through-holes formed in a top portion and a bottom portion thereof, respectively, and disposed within the immersion tank;
an electronic device disposed in the housing in a state of being immersed in the coolant;
a coolant flow path formed between an inner surface of the immersion tank and an outer surface of the housing to couple the through-hole in the top portion of the housing to the through-hole in the bottom portion of the housing so that the coolant flows therethrough; and
a heat pipe arranged through a side wall of the immersion tank, the heat pipe is a hollow cylindrical member, opposite ends of which are closed,
a hydraulic fluid is sealed in the heat pipe, and
the hydraulic fluid transports heat of the coolant in the coolant flow path to an outside of the immersion tank.

### Claim 2 (depends on 1)

The cooling system according to claim 1, wherein both the immersion tank and the housing are configured with a heat insulating member.

### Claim 3 (depends on 1)

The cooling system according to claim 1, wherein the housing has a space therein that is divided into a plurality of chambers by partitions, and a plurality of electronic devices is dispersively arranged in the plurality of chambers.

### Claim 4 (depends on 3)

The cooling system according to claim 3, wherein the plurality of chambers has a conical shape having a wider lower side and a narrower upper side.

### Claim 5 (depends on 3)

The cooling system according to claim 3, wherein the through-holes in the top portion and the bottom portion of the housing have a conical shape having a wider lower side and a narrower upper side.

### Claim 6 (depends on 1)

The cooling system according to claim 1, wherein the electronic device is a server or a storage device.

### Claim 7 (depends on 1)

The cooling system according to claim 1, wherein the heat transported to an outside of the immersion tank by the heat pipe is dissipated to an atmosphere.

### Claim 8

A method of cooling an electronic device, comprising:
disposing a housing having through-holes formed in a top portion and a bottom portion thereof, respectively, in a sealed immersion tank, and disposing an electronic device in the housing so that an inside of the immersion tank is filled with a liquid coolant;
generating, by heat generated in the electronic device, natural convection of the coolant that is discharged out of the housing from the through-hole in the top portion of the housing, passes through a coolant flow path between an outer surface of the housing and an inner surface of the immersion tank, and returns to an inside of the housing from the through-hole in the bottom portion of the housing; and
transporting, by a heat pipe, heat of the coolant that passes through the coolant flow path to an outside of the immersion tank,
the heat pipe is arranged through a side wall of the immersion tank,
the heat pipe is a hollow cylindrical member, opposite ends of which are closed,
a hydraulic fluid is sealed in the heat pipe, and
the hydraulic fluid transports heat of the coolant in the coolant flow path to an outside of the immersion tank.