Thermal management system

• US 6,319,114 B1
• Filed: 11/11/1999
• Issued: 11/20/2001
• Est. Priority Date: 11/11/1999
• Status: Expired due to Term

• Current Assignee: Degree Controls, Inc. (Nova Holdings LLC)
• Original Assignee: Degree Controls, Inc. (Nova Holdings LLC)
• Inventors: Nair, Rajesh, Holman, Roger, Gagnon, David
• Primary Examiner(s): WAYNER, WILLIAM E
• Application Number:
  US09/438,733
• Time in Patent Office: 740 Days
• Field of Search: 95/14, 964/20, 236/49.3, 165/80.3, 454/184, 417/42, 622/592
• US Class Current: 454/184
• CPC Class Codes: B01D 2273/30 Means for generating a circulation of a fluid in a filtration system, e.g. using a pump or a fan
• CPC Class Codes: B01D 46/0086 Filter condition indicators
• CPC Class Codes: B01D 46/448 by temperature measuring
• CPC Class Codes: B01D 46/46 automatic
• CPC Class Codes: G05D 23/1917 using digital means
• CPC Class Codes: G05D 23/1919 characterised by the type of controller
• CPC Class Codes: H05K 7/20181 Filters; Louvers
• CPC Class Codes: H05K 7/20572 within cabinets for removing heat from sub-racks, e.g. plenum
• CPC Class Codes: H05K 7/207 Thermal management, e.g. cabinet temperature control

Abstract

A thermal management system for an enclosure housing devices which generate heat inside the enclosure. A fan, whose speed is responsive to an input signal, has a gas flow output in communication with the enclosure. A filter is disposed in the gas flow path of the fan'"'"'s output. At least one temperature sensor is disposed in the enclosure for measuring the temperature inside the enclosure. A controller adjusts the speed of the fan until the temperature inside the enclosure is within a predetermined range to ensure that the devices inside the enclosure do not overheat. A processor compares the signal input to the fan with the speed of the fan to determine the condition of the fan and, in response to the temperature sensor, determines the condition of the filter.

Claims

1. A thermal management system comprising:

an enclosure housing devices which generate heat;

a fan, whose speed is responsive to an input signal, the fan having a gas flow output in communication with the enclosure;

a filter disposed in the gas flow path of the fan'"'"'s output;

at least one temperature sensor disposed in the enclosure for measuring the temperature inside the enclosure;

a controller for adjusting the speed of the fan until the temperature inside the enclosure is within a predetermined range to ensure that the devices inside the enclosure do not overheat;

means for comparing the input signal to the fan with the speed of the fan to determine the condition of the fan; and

means, responsive to the temperature sensor, for determining the condition of the filter.

2. The system of claim 1 in which the input signal to the fan is a voltage signal and the means for comparing includes a processor programmed to compare the voltage signal with the speed of the fan and to provide an output signal indicative of a poorly operating fan when the voltage signal exceeds a predetermined threshold for a predetermined fan speed.

3. The system of claim 1 in which the means for determining the condition of the filter includes a processor programmed to compare the temperature inside the enclosure with the speed of the fan and to provide an output signal indicative of a clogged filter when the temperature inside the enclosure exceeds a predetermined threshold for a predetermined fan speed.

4. The system of claim 1 in which the means for determining the condition of the filter includes a second temperature sensor disposed to measure the temperature of a gas flow entering the enclosure and a processor, responsive to the second temperature sensor, programmed to compare the temperature of the gas flow entering the enclosure with the temperature inside the enclosure and to provide an output signal indicative of a clogged filter when the difference between the two temperatures exceeds a predetermined threshold at a predetermined fan speed.

5. A thermal management system for an enclosure housing devices which generate heat cooled by a variable speed fan providing a gas flow outlet filtered by a filter, the system comprising:

at least one temperature sensor disposed in the enclosure for measuring the temperature inside the enclosure;

a controller for adjusting the speed of the fan until the temperature inside the enclosure is within a predetermined range to ensure that the devices inside the enclosure do not overheat;

means for determining the condition of the fan; and

means, responsive to the temperature sensor, for determining the condition of the filter.

6. A thermal management system comprising:

an enclosure housing devices which generate heat;

a fan whose speed is responsive to an input signal, the fan having a gas flow output in communication with the enclosure;

a filter disposed in the gas flow path of the fan'"'"'s output;

at least one temperature sensor disposed in the enclosure for measuring the temperature inside the enclosure;

a controller for adjusting the speed of the fan until the temperature inside the enclosure is within a predetermined range to ensure that devices inside the enclosure do not overheat;

at least one gas flow rate sensor disposed to measure the flow rate through the enclosure; and

a processor, responsive to the at least one gas flow rate sensor, programmed to provide an output signal indicative of a clogged filter when the gas flow rate is less than a predetermined level at a predetermined fan speed.

7. A thermal management system comprising:

a temperature sensor for measuring the temperature inside an enclosure to be cooled with a gas flow through a filter from a fan, whose speed depends on a fan input signal; and

a controller responsive to the temperature sensor and connectable to the fan for monitoring the temperature inside the enclosure and adjusting the speed of the fan until the temperature inside the enclosure is within a predetermined range, the controller including;

means for comparing the fan input signal with the speed of the fan to determine the condition of the fan; and

means, responsive to the temperature sensor, for determining the condition of the filter.

8. The system of claim 7 in which the fan input signal is a voltage signal and the means for comparing includes a processor programmed to compare the voltage signal with the speed of the fan and to provide an output signal indicative of a poorly operating fan when the voltage signal exceeds a predetermined threshold for a predetermined fan speed.

9. The system of claim 7 in which the means for determining the condition of the filter includes a processor programmed to compare the temperature inside the enclosure with the speed of the fan and to provide an output signal indicative of a clogged filter when the temperature inside the enclosure exceeds a predetermined threshold for a predetermined fan speed.

10. The system of claim 7 in which the means for determining the condition of the filter includes a second temperature sensor disposed to measure the temperature of a gas flow entering the enclosure and a processor, responsive to the second temperature sensor, programmed to compare the temperature of the gas flow entering the enclosure with the temperature of the inside of the disclosure and to provide an output signal indicative of a clogged filter when the difference between the two temperatures exceeds a predetermined amount at a predetermined fan speed.

11. A thermal management system comprising:

a temperature sensor for measuring the temperature inside an enclosure to be cooled with a gas flow through filter from fan, whose speed depends on a fan input signal; and

a controller responsive to the temperature sensor and connectable to the fan for monitoring the temperature inside the enclosure and adjusting the speed of the fan until the temperature inside the enclosure is within a predetermined range, the controller including means, responsive to the temperature sensor, for determining the condition of the filter.

12. The system of claim 11 further including means for comparing the fan input signal with the speed of the fan to determine the condition of the fan.

13. The system of claim 11 in which the fan input signal is a voltage signal and the means for comparing includes a processor programmed to compare the voltage signal with the speed of the fan and to provide an output signal indicative of a poorly operating fan when the voltage signal exceeds a predetermined threshold for a predetermined fan speed.

14. The system of claim 11 in which the means for determining the condition of the filter includes a processor programmed to compare the temperature inside the enclosure with the speed of the fan and to provide an output signal indicative of a clogged filter when the temperature inside the enclosure exceeds a predetermined threshold for a predetermined fan speed.

15. The system of claim 11 in which the means for determining the condition of the filter includes a second temperature sensor disposed to measure the temperature of a gas flow entering the enclosure and a processor, responsive to the second temperature sensor, programmed to compare the temperature of the gas flow entering the enclosure with the temperature inside the disclosure and to provide an output signal indicative of a clogged filter when the difference between the two temperatures exceeds a predetermined amount at a predetermined fan speed.