Liquid cooling apparatus with improved leakage detection for electronic devices

• US 5,086,829 A
• Filed: 07/05/1991
• Issued: 02/11/1992
• Est. Priority Date: 07/12/1990
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Asakawa, Kyoichi
• Primary Examiner(s): Ford, John K.
• Application Number:
  US07/726,323
• Time in Patent Office: 221 Days
• Field of Search: 165/11.1, 165/12, 165/13, 165/70, 165/80.4, 165/104.33, 361/385
• US Class Current: 165/270
• CPC Class Codes: H05K 7/20281 Thermal management, e.g. liquid flow control

Abstract

A liquid cooling apparatus includes a heat exchanger, a tank, leakage sensors, first and second level sensors, a timer counter, and a control section. The heat exchanger cools a coolant to be supplied to a heat generating portion in an electronic device. The tank temporarily stores the coolant cooled by the heat exchanger before the coolant is supplied to the electronic device. The leakage sensors detect leakage of the coolant in a circulation path for repeatedly performing cooling and heat absorbing operations. The first and second level sensors detect a decrease in amount of the coolant in the tank. The timer counter counts a time interval between the instant at which a leakage detection output is output from one of the leakage sensors and the instant at which a coolant decrease detection output is output from one of the first and second level sensors. The control section stops an operation of the electronic device when a value of the timer counter is a predetermined value or less.

Claims

1. A liquid cooling apparatus characterized by comprising:

a heat exchanger for cooling a coolant to be supplied to a heat generating portion in an electronic device;

a tank for temporarily storing the coolant cooled by said heat exchanger before the coolant is supplied to the electronic device;

leakage detecting means for detecting leakage of the coolant in a circulation path for repeatedly performing cooling and heat absorbing operations;

coolant detecting means for detecting a decrease in amount of the coolant in said tank;

timer counter means for counting a time interval between an instant at which a leakage detection output is output from said leakage detecting means and an instant at which a coolant decrease detection output is output from said coolant detecting means; and

control means for stopping an operation of the electronic device when a value of said timer counter means is not more than a predetermined value.

2. An apparatus according to claim 1, wherein said leakage detection means is arranged in a drain pan of a cooling unit in which said heat exchanger and said tank are arranged.

3. An apparatus according to claim 1, wherein said leakage detecting means is arranged in a drain pan of the electronic device.

4. An apparatus according to claim 1, wherein said leakage detecting means includes a detecting circuit in which two conductive lines connected to each other through a resistor having a high resistance are held to be close to each other so as not to be electrically connected to each other, and a resistance between said conductive lines is reduced upon occurrence of leakage of the coolant, thereby detecting the leakage of the coolant.

5. An apparatus according to claim 1, wherein said coolant detecting means comprises a first level sensor for outputting a detection signal when an amount of coolant in said tank is slightly decreased, and a second level sensor for outputting a detection signal when the amount of coolant in said tank is greatly decreased.

6. An apparatus according to claim 5, wherein said timer counter means counts a time interval between an instant at which a leakage detection output is output from said leakage detecting means and an instant at which a detection output is output from said first level sensor.

7. An apparatus according to claim 5, wherein said control means immediately stops an operation of the electronic device when a detection output is output from said second level sensor.

8. An apparatus according to claim 1, wherein said timer counter means is always reset when no detection signal is output from said leakage detecting means, and a time counting operation thereof is started in response to a first leakage detection output from said leakage detecting means.

9. An apparatus according to claim 1, wherein said control means stops an operation of the electronic device by turning off a power supply therefor.