US5215704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for in situ testing of heat exchangers
Assignee: Electric Power Research Institute
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Filing: 1991-06-24
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Granted: 1993-06-01
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Expires: 2011-06-24
Abstract
Abstract Using the method of this invention, the performance of a heat exchanger is determined by measuring the heat transfer capabilities of an individual tube. A relatively small reservoir of service fluid is connected to the inlet and outlet ports of a tube. The reservoir is provided with a heater or chiller and the service fluid is circulated through the tube. When a steady state is reached, the heat transfer characteristics of the tube are measured using known mathematical relationships.
Inventors
- 👤 Norris S. Hirota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:31
CPC Classifications
F; F28; F28F; F28F19/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
173 words
A method of determining the extent of fouling in a heat exchanger including a plurality of tubes, the tubes of said heat exchanger being fouled to some degree, said method comprising the steps of: connecting a test reservoir to an inlet port and an outlet port of one of said tubes, said one of said tubes remaining in place in said heat exchanger; circulating a service fluid from said test reservoir through said one of said tubes; altering the heat content of said service fluid in said test reservoir; and detecting (a) the temperature of said service fluid at the respective ends of said tube, (b) the flow rate of said service fluid, and (c) the temperature of a process fluid on the outside of said tube; using the values of said items (a), (b) and (c) to compute a heat transfer efficiency for said one of said tubes; using the heat transfer efficiency of said one of said tubes to determine the extent of fouling of the tubes in said heat exchanger.
Claim 2
Independent Claim
173 words
A method of determining the extent of fouling in a heat exchanger including a plurality of tubes, the tubes of said heat exchanger being fouled to some degree, said method comprising the steps of: connecting a test reservoir to an inlet port and an outlet port of one of said tubes, said one of said tubes remaining in place in said heat exchanger; circulating a service fluid from said test reservoir through said one of said tubes; altering the heat content of said service fluid in said test reservoir; and detecting (a) the temperature of said service fluid at the respective ends of said tube, (b) the flow rate of said service fluid, and (c) the temperature of a process fluid on the outside of said tube; using the values of said items (a), (b) and (c) to compute a heat transfer efficiency for said one of said tubes; using the heat transfer efficiency of said one of said tubes to determine the extent of fouling of the tubes in said heat exchanger.
Claim 3
Dependent Claim
85 words
The method of claim 1, said method being used to determine the extent of fouling of a heat exchanger in a nuclear power plant, said heat exchanger being intended to remove heat from said process fluid in the event of an accident in said nuclear power plant, said heat exchanger transferring a substantially lower quantity of heat when said nuclear power plant is in normal operation than said heat exchanger is required to transfer in the event of an accident in said nuclear power plant.
Claim 4
Dependent Claim
22 words
The method of claim 1 comprising the step of determining the fouling resistance (r f ) of said one of said tubes.
Claim 5
Dependent Claim
34 words
A method of determining the extent of fouling of a heat exchanger comprising performing the method of claim 1 on a plurality but substantially less than all of the tubes in a heat exchanger.
Claim 6
Dependent Claim
31 words
The method of claim 4 comprising performing the method of claim 1 on at least six tubes but less than 10% of the total number of tubes in said heat exchanger.
Claim 7
Dependent Claim
11 words
The method of claim 5 wherein said tubes are selected randomly.
Claim 8
Dependent Claim
196 words
A combination in a nuclear power plant, said combination comprising: a heat exchanger for removing heat from a heated fluid in the event of an accident in said nuclear power plant, said heat exchanger comprising a plurality of tubes, said heat exchanger transferring a substantially lower quantity of heat when said nuclear power plant is in normal operation than said heat exchanger is required to transfer in the event of an accident in said nuclear power plant; apparatus conducting a test to determine the extent of fouling of said heat exchanger, said apparatus comprising; a test reservoir for a service fluid and a means for changing the heat content of said service fluid; means for connecting said test reservoir to the respective ends of at least one but substantially less than all of said tubes; means for calculating said service fluid through said at least one of said tubes; and means for detecting the temperature of said service fluid at the respective ends of said at least one of said tubes, the flow rate of said service fluid, and the temperature of a process fluid on the outside of said at least one of said tubes.
Claim 9
Dependent Claim
196 words
A combination in a nuclear power plant, said combination comprising: a heat exchanger for removing heat from a heated fluid in the event of an accident in said nuclear power plant, said heat exchanger comprising a plurality of tubes, said heat exchanger transferring a substantially lower quantity of heat when said nuclear power plant is in normal operation than said heat exchanger is required to transfer in the event of an accident in said nuclear power plant; apparatus conducting a test to determine the extent of fouling of said heat exchanger, said apparatus comprising; a test reservoir for a service fluid and a means for changing the heat content of said service fluid; means for connecting said test reservoir to the respective ends of at least one but substantially less than all of said tubes; means for calculating said service fluid through said at least one of said tubes; and means for detecting the temperature of said service fluid at the respective ends of said at least one of said tubes, the flow rate of said service fluid, and the temperature of a process fluid on the outside of said at least one of said tubes.
Claim 10
Dependent Claim
16 words
The arrangement of claim 7 comprising a computer, said detection means being connected to said computer.
Claim 11
Dependent Claim
20 words
The arrangement of claim 7 wherein said means for exchanging the heat content of said service fluid comprises a heater.
Claim 12
Dependent Claim
20 words
The arrangement of claim 7 wherein said means for exchanging the heat content of said service fluid comprises a chiller.
Claim 13
Dependent Claim
15 words
The arrangement of claim 7 wherein said service fluid and said process fluid are liquids.
Claim 14
Dependent Claim
25 words
The arrangement of claim 7 wherein said apparatus is configured so as to be disconnected from said test exchanger when said test has been completed.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-31 | 1996-11-30 | 1997-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-31 | 2000-11-30 | 2001-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-31 | 2004-11-30 | 2005-06-01 | $7700.00 | Window Closed / Lapsed |