Multifan-equipped apparatus for cooling objects mounted at local interior regions and provided with fan-unit assembly and operation monitoring means having an error detector

• US 6,814,546 B2
• Filed: 03/28/2002
• Issued: 11/09/2004
• Est. Priority Date: 09/19/2001
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Sekiguchi, Takashi
• Primary Examiner(s): Yu, Justine
• Assistant Examiner(s): Sayoc, Emmanuel
• Application Number:
  US10/112,474
• Publication Number:
  US 20030053913A1
• Time in Patent Office: 957 Days
• Field of Search: 417/3, 417/18, 417/22, 417/32, 417/42, 417/426, 417/63, 417/688, 361/688, 361/690, 361/695, 318/111, 318/112, 318/113
• US Class Current: 417/3
• CPC Class Codes: F04D 25/166 using fans
• CPC Class Codes: F04D 27/004 by varying driving speed
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A multifan-equipped apparatus in which a plurality of objects mounted are controllably cooled by blowing air using a fan-unit assembly composed of a plurality of fan units. The plural fan units are divided into a plurality of groups; the fan units in the same group are arranged in a queue. And one of the fan units of each group is a master fan unit that is autonomically adjustable in revolutions per minute (rpm) in accordance with a current apparatus-environment temperature and serves to make a tuning control on the rpm of at least one of the remaining fan units in the same group so as to adjust the rpm to a first estimated value corresponding to the autonomic-adjusted rpm of the master fan unit. If an error has occurred in the state of operation of a fan unit of a group as the operation of every fan unit is monitored, the current rpm of the master fan unit of at least one necessary group is set to a second estimated value for a back-up control minimizing a possible loss of cooling performance of the fan-unit assembly due to the occurrence of the error.

Claims

1. A multifan-equipped apparatus in which a plurality of objects mounted at different local interior regions are controllably cooled by blowing air, comprising:

a fan-unit assembly, composed of a plurality of fan units that are divided into a plurality of groups disposed at respective local interior regions, for blowing air over the objects to cool, the plural fan units in the same group being arranged in a queue along the corresponding local interior region;

one of said plural fan units of each group being a master fan unit that is autonomically adjustable in revolutions per minute (rpm) in accordance with a current apparatus-environment temperature at the corresponding local interior region and serves to make a tuning control on the rpm of at least one of the remaining fan units in the same group so as to adjust the rpm of said at least one of the remaining fan units in the same group to a first estimated value corresponding to the rpm of said master fan unit; and

means for monitoring an operational state of every fan unit of each group and, if an error occurs in the operational state of a fan unit of a group, means of setting the current rpm of said master fan unit of at least one other group to a second estimated value for a back-up control minimizing a possible loss of cooling performance of said fan-unit assembly due to the occurrence of the error.

2. A multifan-equipped apparatus according to claim 1, wherein said monitoring means includes an error detector for periodically or non-interruptedly monitoring every fan unit by polling as to whether or not an error has occurred in the operational state and judging a fan unit as having encountered such error.

3. A multifan-equipped apparatus according to claim 2, wherein said master fan unit of each group includes:

a temperature sensor for detecting said temperature;

a first control-signal selector selecting for output either of a signal responsive to said temperature sensor or a signal responsive to said monitoring means, said output being a predetermined rpm-control reference signal; and

an autonomic controller for autonomically controlling the rpm of said master fan unit based on said predetermined rpm-control reference signal,

wherein said predetermined rpm-control reference signal also servers as a tuning control signal to control the rpm of said at least one of the remaining fan units.

4. A multifan-equipped apparatus according to 3, wherein said autonomic controller includes:

an autonomic-control-table holder for holding an autonomic-control table that is defined by first rpm information and second rpm information, which is preset with respect to the temperature, and third rpm information linearly ranging between said first rpm information and said second rpm information; and

an rpm-control-signal generator for generating an rpm-control signal that controls the rpm of said master fan unit, based on both said rpm-control reference signal and said autonomic-control table.

5. A multifan-equipped apparatus according to claim 4, wherein said autonomic controller further includes:

an rpm detector for detecting a current rpm of said master fan unit; and

a comparator and controller unit for comparing the output of said rpm-control-signal generator with the output of said rpm detector in voltage, and performing a feedback control on the detected rpm of said master fan unit so as to minimize a voltage difference of such two outputs.

6. A multifan-equipped apparatus according to claim 5, wherein said autonomic controller further includes:

a first filter circuit for filtering the output voltage of said rpm detector as one of the two voltages to be compared by said comparator and controller unit; and

a second filter circuit for filtering the output voltage of said rpm-control-signal generator as the other of the two voltages to be compared by said comparator and controller unit;

a time constant preset for said second filter circuit being larger than that preset for said first filter circuit.

7. A multifan-equipped apparatus according to claim 4, wherein said control-table holder and said rpm-control-signal generator include:

a first reference-voltage generator for generating a first reference voltage as a function of said first rpm information;

a comparator and amplifier unit for comparing a voltage value of said rpm-control reference signal with said first reference voltage and outputting said voltage value of said rpm-control reference voltage if said first reference voltage is larger than said voltage value, and for linearly amplifying said first reference voltage by a predetermined constant and outputting the resulting reference voltage if said voltage value of said rpm-control reference signal is larger than said first reference voltage;

a second reference-voltage generator for generating a second reference voltage commensurate with said second rpm information; and

a comparator and controller for comparing the output voltage value of said comparator and amplifier unit with said second reference voltage and, if said output voltage value of said comparator and amplifier unit is larger than said second reference voltage, outputting said second reference voltage as said rpm-control signal and, if said second reference voltage is larger than said output voltage value of said comparator and amplifier unit, outputting said output voltage value of said comparator and amplifier unit as said voltage value of said rpm-control signal.

8. A multifan-equipped apparatus according to claim 5, wherein:

said rpm detector includes a voltage converter for convening said rpm of said master fan unit, which is detected by said rpm detector, into a voltage value; and

said autonomic controller includes an error detector for comparing a threshold voltage value corresponding to an rpm value indicative of occurrence of an error, and detecting occurrence of an error due to a possible lowered rpm, as the result of the comparison, which error occurrence is to be notified to said master fan unit by a warning signal.

9. A multifan-equipped apparatus according to claim 8, further comprising a substrate on which said fan units are mounted,

said substrate having a card-edge interface that is electrically connectable to an external tester, which performs an operation test on individual fan units, so that every fan unit can receive a testing signal from the external tester via said card-edge interface when said card-edge interface is fitted in a mating connector of the external tester.

10. A multifan-equipped apparatus according to claim 9, wherein said rpm detector of each said fan unit receives a test rpm signal, which is to be used as said testing signal in resting the operation of said error detector, via said card-edge interface.

11. A multifan-equipped apparatus according to claim 9, wherein one or more identifications respectively unique to one or more items to be tested is assigned to said card-edge interface.

12. A multifan-equipped apparatus according to claim 10, wherein one or more identifications respectively unique to one or more items to be tested is assigned to said card-edge interface.

13. A multifan-equipped apparatus according to claim 2, wherein every fan unit except said master fan unit in each group includes:

a temperature sensor for detecting said temperature;

a first control-signal selector selecting for output either of a signal responsive to said temperature sensor or a second control signal, said output being a predetermined rpm-control reference signal; and

;

an autonomic controller for autonomically controlling the rpm of a respective fan unit based on the predetermined rpm-control reference signal,

wherein said second control signal is a control signal received from one of said master fan unit and said monitoring means, and

wherein said predetermined rpm-control reference signal also servers as a tuning control signal to control the rpm of said at least one other of the remaining fan units.

14. A multifan-equipped apparatus according to 13, wherein said autonomic controller includes:

an autonomic-control-table holder for holding an autonomic-control table that is defined by first rpm information and second rpm information, which are preset with respect to the temperature, and third rpm information linearly ranging between said first rpm information and said second rpm information; and

an rpm-control-signal generator for generating an rpm-control signal that controls the rpm of said respective fan unit based on both said rpm-control reference signal and said autonomic-control table.

15. A multifan-equipped apparatus according to claim 14, wherein said autonomic controller further includes:

an rpm detector for detecting a current rpm of said fan unit; and

a comparator and controller unit for comparing the output of said rpm-control-signal generator with the output of said rpm detector in voltage, and performing a feedback control on the detected rpm of said fan unit so as to minimize a voltage difference of such two outputs.

16. A multifan-equipped apparatus according to claim 15, wherein said autonomic controller further includes:

a first filter circuit for filtering the output voltage of said rpm detector as one of the two voltages to be compared by said comparator and controller unit; and

a second filter circuit for filtering the output voltage of said rpm-control-signal generator as the other of the two voltages to be compared by said comparator and controller unit;

a time constant preset for said second filter circuit being larger than that present for said first filter circuit.

17. A multifan-equipped apparatus according to claim 14, wherein said rpm-control-signal generator includes:

a first reference-voltage generator for generating a first reference voltage as a function of said first rpm information;

a comparator and amplifier unit for comparing a voltage value of said rpm-control reference signal with said first reference voltage and outputting said voltage value of said rpm-control reference voltage if said first reference voltage is larger than said voltage value, and for linearly amplifying said first reference voltage by a predetermined constant and outputting the resulting reference voltage if said voltage value is larger than said first reference voltage;

a second reference-voltage generator for generating a second reference voltage commensurate with said second rpm information; and

a comparator and controller unit for comparing the output voltage value of said comparator and amplifier unit with said second reference voltage and, if said output voltage value of said comparator and amplifier unit is larger than said second reference voltage, outputting said second reference voltage as said rpm-control signal and, if said second reference voltage is larger than said output voltage value comparator and amplifier unit, outputting said output voltage value of said comparator and amplifier unit as said voltage value of said rpm-control signal.

18. A multifan-equipped apparatus according to claim 15, wherein:

said rpm detector includes a voltage converter for convening rpm of said fan unit, which is detected by said rpm detector, into a voltage value; and

said autonomic controller includes an error detector for comparing a threshold voltage value corresponding to an rpm value indicative of occurrence of an error, and detecting occurrence of an error due to a possible lowered rpm, as the result of the comparison, which is to be notified to said master fan unit by a warning signal.

19. A multifan-equipped apparatus according to claim 18, further comprising a substrate on which said fan units are mounted,

said substrate having a card-edge interface that is electrically connectable to an external tester, which performs an operation test on the individual fan units, so that every fan unit can receive a testing signal from said tester via said card-edge interface when said card-edge interface is fitted in a mating connector of the external tester.

20. A multifan-equipped apparatus according to claim 19, Wherein said rpm detector of each said fan unit receives a test rpm signal, which is to be used as said testing signal in resting the operation of said error detector, via said card-edge interface.

21. A multifan-equipped apparatus according to claim 19, wherein one or more identifications respectively unique to one or more items to be tested is assigned to said card-edge interface.

22. A multifan-equipped apparatus according to claim 20, wherein one or mote identifications respectively unique to one or more items to be tested is assigned to said card-edge interface.

23. A multifan-equipped apparatus according to claim 1, wherein said master fan unit of each group includes:

a first temperature sensor for detecting said temperature;

an autonomic cent-roller for autonomically controlling the rpm of said master fan unit based on a predetermined rpm-control reference signal; and

a first control-signal selector receiving as inputs a first control signal, which is responsive to said temperature sensor, and a second control signal, which is responsive to said monitoring means, and selectively outputting one of the first control signal and the second control signal,

wherein said first control-signal selector output is both the predetermined rpm-control reference signal and a tuning control signal to control the rpm of said at least one of the remaining fan units.

24. A multifan-equipped apparatus according to 23, wherein said autonomic controller includes;

an autonomic-control-table holder for holding an autonomic-control table that is defined by first rpm information and second rpm information, which are preset with respect to the temperature, and third rpm information linearly ranging between said first rpm information and said second rpm information; and

an rpm-control-signal generator for generating an rpm-control signal that controls the rpm of a master fan unit based on both said predetermined rpm-control reference signal and said autonomic-control table held by said autonomic-control-table holder.

25. A multifan-equipped apparatus according to claim 24, wherein said autonomic controller further includes:

an rpm detector for detecting a current rpm of said master fan unit; and

a comparator and controller unit for comparing the output of said rpm-control-signal generator with the output of said rpm detector in voltage, and performing a feedback control on the detected rpm of said master fan unit so as to minimize a voltage difference of such two outputs as the result of comparison by said comparator and controller unit.

26. A multifan-equipped apparatus according to claim 25, wherein said autonomic controller further includes:

a first filter circuit for filtering the output voltage of said rpm detector as one of the two voltages to be compared by said comparator and controller unit; and

a second filter circuit for filtering the output voltage of said rpm-control-signal generator as the other of the two voltages to be compared by said comparator and controller unit;

a time constant preset for said second filter circuit being larger than that preset for said first filter circuit.

27. A multifan-equipped apparatus according to claim 24, wherein said rpm-control-signal generator includes:

a first reference-voltage generator for generating a first reference voltage as a function of said first rpm information;

a comparator and amplifier unit for comparing a voltage value of said rpm-control reference signal with said first reference voltage and outputting said voltage value if said first reference voltage is larger than said voltage value, and for linearly amplifying said first reference voltage by a predetermined constant and outputting the resulting reference voltage if said voltage value is larger than said first reference voltage;

a second reference-voltage generator for generating a second reference voltage commensurate with said second rpm information; and

a comparator for comparing the output voltage value of said comparator and amplifier unit with said second reference voltage and, if said output voltage value of said comparator and amplifier unit is larger than said second reference voltage, outputting said second reference voltage as said rpm-control signal and, if said second reference voltage is larger than said output voltage value of said comparator and amplifier unit, outputting said output voltage value of said comparator and amplifier unit as said voltage value of said rpm-control signal.

28. A multifan-equipped apparatus according to claim 25, wherein:

said rpm detector includes a voltage converter for convening said rpm of said master fan unit, which is detected by said rpm detector, into a voltage value; and

said autonomic controller includes an error detector for comparing a threshold voltage value corresponding to an rpm value indicative of occurrence of an error, and detecting occurrence of an error due to a possible lowered rpm, as the result of the comparison, which is to be notified to said master fan unit by a warning signal.

29. A multifan-equipped apparatus according to claim 28, further comprising a substrate on which said fan units are mounted,

said substrate having a card-edge interface that is electrically connectable to an external tester, which performs an operation test on the individual fan units, so that every fan unit can receive a testing signal from the external tester via said card-edge interface when said card-edge interface is fitted in a mating connector of the external tester.

30. A multifan-equipped apparatus according to claim 29, wherein said rpm detector of each said fan unit receives a test rpm signal, which is to be used as said testing signal in testing the operation of said error detector, via said card-edge interface.

31. A multifan-equipped apparatus according to claim 29, wherein one or more identifications respectively unique to one or more items to be rested is assigned to said card-edge interface.

32. A multifan-equipped apparatus according to claim 30, wherein one or more identifications respectively unique to one or more items to be tested is assigned to said card-edge interface.

33. A multifan-equipped apparatus according to claim 1, wherein every fan unit except said master fan unit in each group includes:

a temperature sensor for detecting said temperature;

an autonomic controller for autonomically controlling the rpm of a respective fan unit based on a predetermined rpm-control reference signal; and

a second control-signal selector for selectively outputting a first control signal responsive to the temperature detected by said temperature sensor as said rpm-control reference signal to said autonomic controller and also as a tuning-control signal to at least one other fan unit for the tuning control, and a second control signal, which is received from said master fan unit or said monitoring means for the back-up control as said rpm-control reference signal to said autonomic controller and also as a tuning-control signal to said at least one other fan unit.

34. A multifan-equipped apparatus according to 33, wherein said autonomic controller includes:

an autonomic-control-table holder for holding an autonomic-control table that is defined by first rpm information and second rpm information, which are preset with respect to the temperature, and third rpm information linearly ranging between said first rpm information and said second rpm information; and

an rpm-control-signal generator for generating an rpm-control signal that controls a fan of said respective fan unit in rpm based on both said rpm-control reference signal from said second control-signal selector and said autonomic-control table held by said autonomic-control-table holder.

35. A multifan-equipped apparatus according to claim 34, wherein said autonomic controller further includes:

an rpm detector for detecting a current rpm of said fan, and

a comparator and controller unit for comparing the output of said rpm-control-signal generator with the output of said rpm detector in voltage, and performing a feedback control on the detected rpm of said fan so as to minimize a voltage difference of such two outputs as the result of comparison by said comparator and controller unit.

36. A multifan-equipped apparatus according to claim 35, wherein said autonomic controller further includes:

a first filter circuit for filtering the output voltage of said rpm detector as one of the two voltages to be compared by said comparator and controller unit; and

a second filter circuit for filtering the output voltage of said rpm-control-signal generator as the other of the two voltages to be compared by said comparator and controller unit;

a time constant preset for said second filter circuit being larger than that preset for said first filter circuit.

37. A multifan-equipped apparatus according to claim 34, wherein said rpm-control-signal generator includes:

a first reference-voltage generator for generating a first reference voltage as a function of said first rpm information;

a comparator and amplifier unit for comparing a voltage value of said rpm-control reference signal with said first reference voltage generated by said first reference-voltage generator and outputting said voltage value of said rpm-control reference voltage if said reference voltage is larger than said voltage value, and for linearly amplifying said first reference voltage by a predetermined constant and outputting the resulting reference voltage if said voltage value of said rpm-control reference signal is larger than said voltage value;

a second reference-voltage generator for generating a second reference voltage commensurate with said second rpm information; and

a comparator and controller unit for comparing the output voltage value of said comparator and amplifier unit with said second reference voltage from said second reference-voltage generator and, if said output voltage value of said comparator and amplifier unit is larger than said second reference voltage, outputting said second reference voltage as said rpm-control signal and, if said second reference voltage is larger than said output voltage value of said comparator and amplifier unit, outputting said output voltage value of said comparator and amplifier unit as said voltage value of said rpm-control signal.

38. A multifan-equipped apparatus according to claim 35, wherein:

said rpm detector includes a voltage converter for converting the rpm of said fan which is detected by said rpm detector, into a voltage value; and

said autonomic controller includes an error detector for comparing a threshold voltage value corresponding to an rpm value indicative of occurrence of an error, and detecting occurrence of an error due to a possible lowered rpm, as the result of the comparison, which is to be notified to said master fan unit by a warning signal.

39. A multifan-equipped apparatus according to claim 38, further comprising a substrate on which said fan units are mounted,

said substrate having a card-edge interface that is electrically connectable to an external tester, which performs an operation test on the individual fan units, so that every fan unit can receive a resting signal from said tester via said card-edge interface when said card-edge interface is fitted in a mating connector of the external tester.

40. A multifan-equipped apparatus according to claim 39, wherein said rpm detector of each said fan unit receives a test rpm signal, which is to be used as said testing signal in testing the operation of said error detector, via said card-edge interface.

41. A multifan-equipped apparatus according to claim 39, wherein one or more identifications respectively unique to one or more items to be tested is assigned to said card-edge interface.

42. A multifan-equipped apparatus according to claim 40, wherein one or more identifications respectively unique to one or more items to be tested is assigned to said card-edge interface.

43. A multifan-equipped apparatus according to claim 1, further comprising a substrate on which said fan units are mounted,

said substrate having a card-edge interface that is electrically connectable to an external tester, which performs an operation test on the individual fan units, so that every fan unit can receive a resting signal from the external tester via said card-edge interface when said card-edge interface is fitted in a mating connector of the external tester.

44. A multifan-equipped apparatus according to claim 43, wherein one or more identifications respectively unique to one or more items to be tested is assigned to said card-edge interface.

45. A multifan-equipped apparatus in which a plurality of objects mounted at different local interior regions are controllably cooled by blowing air, comprising:

a fan-unit assembly, composed of a plurality of fan units that are divided into a plurality of groups disposed across the different local interior regions, for blowing air over the object elements to cool, the plural fan units in the same group being arranged in a queue along a common air flow;

one of the plural fan units of each group being a master fan unit that is autonomically adjustable in revolutions per minute (rpm) in accordance with an apparatus-environment temperature in the corresponding local interior region and serves to make a tuning control on the rpm of at least one of the remaining fan units in each said group so as to adjust the rpm of said at least one of the remaining fan units in each said group to a first estimated value corresponding to the rpm of said master fan unit; and

means for monitoring the operational state of every fan unit of each group and, if an error occurs in the operational state of a fan unit of a group, setting the current rpm of said master fan unit of at least one necessary group to a second estimated value for a back-up control minimizing a possible loss of cooling performance of said fan-unit assembly due to the occurrence of the error.

46. A multifan-equipped apparatus in which a plurality of objects mounted at different local interior regions are controllably cooled by blowing air, comprising:

a fan-unit assembly, composed of a plurality of fan units that are divided into a plurality of groups disposed along the respective local interior regions or across the different local interior regions, for blowing air over the objects to cool, the plural fan units in the same group being arranged in a queue and common in direction of blowing air; and

means for monitoring the operational state of every fan unit of each group and, if an error occurs in the operational state of a fan unit of a group, varying revolutions per minute (rpm) of the fan units of as least one other group in accordance with a current apparatus-environment temperature in the corresponding local interior region using common control information, which is transmitted between the fan units of the other group, to an estimated value for necessary coordinated control minimizing a possible loss of cooling performance of said fan-unit assembly due to the occurrence of the error, thereby controlling the rpm of the fan units of said fan-unit assembly in terms of groups using the common control information for the same group.