US6560980B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling evaporator and condenser fans in a refrigeration system
Assignee: Thermo King Corp
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Filing: 2001-04-10
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Granted: 2003-05-13
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Expires: 2021-04-10
Abstract
Abstract A method and apparatus for controlling evaporator and condenser fans in a refrigeration system. The apparatus is a refrigeration system including a refrigerant circuit defined by a compressor, a condenser, a throttling device, and an evaporator. The apparatus includes an evaporator fan and a condenser fan. The apparatus also includes a controller coupled to the fans. The controller includes a variable frequency drive unit. For the method of the invention, the speed of the fans is controlled by the controller.
Inventors
- 👤 Alan Gustafson
- 👤 Dermott Crombie
- 👤 Mark Freese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:46
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/02; F25B2600/00; F25B2600/11; F25B2600/111; F25B2600/112; F25B2700/00; F25B2700/15; F25B2700/21; F25B2700/2116; F25B2700/2117; F25B2700/21174; F25B2700/21175; F25B49/027; F25D; F25D17/00; F25D17/04; F25D17/06; F25D29/00; F25D29/003; Y; Y02; Y02B; Y02B30/00; Y02B30/70
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
121 words
A refrigeration system comprising: a refrigerant circuit defined by a compressor, a condenser, a throttling device, and an evaporator; at least one evaporator fan; a first sensor positioned adjacent to the evaporator inlet for sensing the temperature of air flowing into the evaporator; a second sensor positioned adjacent to the evaporator outlet for sensing the temperature of air flowing out of the evaporator; and a controller coupled to the at least one evaporator fan and communicating with the first sensor and the second sensor, the controller including a variable frequency drive unit for providing variable frequency power to the at least one evaporator fan, the controller adjusting power provided to the at least one evaporator fan based on the sensed temperatures.
Claim 2
Dependent Claim
121 words
A refrigeration system comprising: a refrigerant circuit defined by a compressor, a condenser, a throttling device, and an evaporator; at least one evaporator fan; a first sensor positioned adjacent to the evaporator inlet for sensing the temperature of air flowing into the evaporator; a second sensor positioned adjacent to the evaporator outlet for sensing the temperature of air flowing out of the evaporator; and a controller coupled to the at least one evaporator fan and communicating with the first sensor and the second sensor, the controller including a variable frequency drive unit for providing variable frequency power to the at least one evaporator fan, the controller adjusting power provided to the at least one evaporator fan based on the sensed temperatures.
Claim 3
Dependent Claim
18 words
The refrigeration system of claim 1 wherein the at least one evaporator fan is a continuously-variable speed fan.
Claim 4
Dependent Claim
46 words
The refrigeration system of claim 1 and further comprising at least one condenser fan and a third sensor coupled to the condenser for sensing a temperature of the condenser, and wherein the controller adjusts a condenser fan speed based on the sensed temperature of the condenser.
Claim 5
Dependent Claim
118 words
A refrigeration system comprising: a refrigerant circuit defined by a compressor, a condenser, a throttling device, and an evaporator; at least one evaporator fan; a controller coupled to the at least one evaporator fan, the controller including a variable frequency drive unit for providing variable frequency power to the at least one evaporator fan; and at least one sensor coupled to the refrigerant circuit for sensing a system parameter, wherein the at least one sensor includes a first sensor for sensing the temperature of air flowing into the evaporator and a second sensor for sensing the temperature of air flowing out of the evaporator, and wherein the controller adjusts an evaporator fan speed based on the sensed temperatures.
Claim 6
Dependent Claim
118 words
A refrigeration system comprising: a refrigerant circuit defined by a compressor, a condenser, a throttling device, and an evaporator; at least one evaporator fan; a controller coupled to the at least one evaporator fan, the controller including a variable frequency drive unit for providing variable frequency power to the at least one evaporator fan; and at least one sensor coupled to the refrigerant circuit for sensing a system parameter, wherein the at least one sensor includes a first sensor for sensing the temperature of air flowing into the evaporator and a second sensor for sensing the temperature of air flowing out of the evaporator, and wherein the controller adjusts an evaporator fan speed based on the sensed temperatures.
Claim 7
Dependent Claim
22 words
The refrigeration system of claim 4 wherein the controller includes an alternating current power source coupled to the variable frequency drive unit.
Claim 8
Dependent Claim
25 words
The refrigeration system of claim 5 wherein the controller includes a microprocessor coupled to the at least one sensor and the variable frequency drive unit.
Claim 9
Dependent Claim
14 words
The refrigeration system of claim 6 and further comprising at least one condenser fan.
Claim 10
Dependent Claim
15 words
The refrigeration system of claim 7 wherein the condenser fan is a continuously-variable speed fan.
Claim 11
Dependent Claim
41 words
The refrigeration system of claim 7 wherein the at least one sensor includes a third sensor coupled to the condenser for sensing the temperature of the condenser, and wherein the controller adjusts a condenser fan speed based on the sensed temperature.
Claim 12
Dependent Claim
83 words
The refrigeration system of claim 7 wherein the controller includes a first switch, a first input to the first switch coupled to the alternating current power source, a second input to the first switch coupled to the variable frequency drive unit, and an output from the first switch coupled to a first input of a second switch, a second input to the second switch coupled to a ground, and an output from the second switch coupled to the at least one condenser fan.
Claim 13
Dependent Claim
19 words
The refrigeration system of claim 10 wherein the first switch and the second switch are coupled to the microprocessor.
Claim 14
Dependent Claim
57 words
The refrigeration system of claim 11 wherein the microprocessor controls the first switch and the second switch in order to provide power to the at least one condenser fan in the form of a one of alternating current power, alternating current power cycled with variable frequency drive power, and variable frequency drive power cycled with no power.
Claim 15
Independent Claim
80 words
A method of controlling the speed of at least one evaporator fan in a refrigeration system, the refrigeration system including a compressor, a condenser, a throttling device, and an evaporator, the method comprising: providing a desired temperature differential for a conditioned space; measuring temperature at the inlet to the evaporator; measuring temperature at the outlet to the evaporator; calculating an actual temperature differential; and adjusting an evaporator fan speed based on the desired temperature differential and the actual temperature differential.
Claim 16
Independent Claim
80 words
A method of controlling the speed of at least one evaporator fan in a refrigeration system, the refrigeration system including a compressor, a condenser, a throttling device, and an evaporator, the method comprising: providing a desired temperature differential for a conditioned space; measuring temperature at the inlet to the evaporator; measuring temperature at the outlet to the evaporator; calculating an actual temperature differential; and adjusting an evaporator fan speed based on the desired temperature differential and the actual temperature differential.
Claim 17
Dependent Claim
26 words
The method of claim 13 wherein adjusting an evaporator fan speed includes adjusting the frequency of the power delivered to the at least one evaporator fan.
Claim 18
Dependent Claim
26 words
The method of claim 13 and further comprising determining whether the actual temperature differential is greater than, less than, or equal to the desired temperature differential.
Claim 19
Dependent Claim
29 words
The method of claim 15 wherein adjusting an evaporator fan speed includes increasing the evaporator fan speed if the actual temperature differential is greater than the desired temperature differential.
Claim 20
Dependent Claim
29 words
The method of claim 15 wherein adjusting an evaporator fan speed includes maintaining the evaporator fan speed if the actual temperature differential is equal to the desired temperature differential.
Claim 21
Dependent Claim
29 words
The method of claim 15 wherein adjusting an evaporator fan speed includes decreasing the evaporator fan speed if the actual temperature differential is less than the desired temperature differential.
References Cited (Backward Citations)
US4474027A
Cited
US4748822A
Cited
US4803848A
Cited
US4856286A
Cited
US5138844A
Cited
US5253483A
Cited
US5062276A
Cited
US5046326A
Cited
US5144812A
Cited
US5255530A
Cited
US5533352A
Cited
US5613369A
Cited
US5657638A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-05-12 | 2006-11-11 | 2007-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-05-12 | 2010-11-11 | 2011-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-05-12 | 2014-11-11 | 2015-05-13 | $7700.00 | Window Closed / Lapsed |