EP0155826A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Heat exchanger performance monitors
Assignee: INTERNATIONAL CONTROL AUTOMATION FINANCE SA
•
Filing: 1985-03-15
•
Granted: —
•
Expires: 2005-03-15
Abstract
Abstract A performance monitor (20) generates a fouling factor (FF) which indicates the level of fouling of a heat exchanger (10) having a heat exchange surface area and through which passes a heat exchange medium having a known specific heat. Temperature transmitters (TT,, TT 2 , TT 3 ) are utilised to obtain values for the input and output temperatures of the heat exchange medium as well as the temperature in the heat exchanger of a heat exchange fluid used to transfer heat to or from the heat exchange medium. Modules (30, 40, 50, 60) are used to generate values for an actual heat transfer coefficient (U act ) and a nominal heat transfer coefficient (U ava ) in the heat exchanger (10) as a function of the temperatures, flow rate and constant parameters such as area and specific heat, for the heat exchanger (10). The actual heat transfer coefficient (U act ) is compared with the nominal or original heat transfer coefficient (U ava ) to determine if there is any deterioration in the coefficients which reflects fouling of the heat exchanger. A simple ratio of the nominal to actual heat transfer coefficients is taken (61) as a measure of the fouling factor (FF).
Inventors
- 👤 Azmi Kaya
- 👤 Marion Alvah Keyes
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 11:49
CPC Classifications
G; G01; G01K; G01K17/00; G01N; G01N25/00; G01N25/18; F; F22; F22B; F22B37/00; F22B37/02; F22B37/56; F25; F25B; F25B49/00; F28; F28F; F28F19/00; F28F27/00; G01L; G01L3/00; G01L3/26
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
265 words
A performance monitor for generating a fouling factor of a heat exchanger having a heat exchange surface area against one side of which a heat exchange medium passes, the medium having a specific heat value, the performance monitor comprising: first temperature transmitter means (TT 1 ) for supplying a signal corresponding to an output temperature (T cold ) of heat exchange medium from the heat exchanger (10); second temperature transmitter means (TT 2 ) for supplying a signal corresponding to an input temperature (T hot ) of medium to the heat exchanger (10); third temperature transmitter means (TT 3 ) for supplying a signal corresponding to a temperature of the heat exchanger (10) on an opposite side of the heat exchange surface area; mass flow rate means for supplying a signal corresponding to a mass flow rate of medium through the heat exchanger (10); an actual heat transfer module (60) connected to the first, second and third temperature transmitter means (TT 1 , TT 2 , TT 3 ) and to the mass flow rate means for calculating an actual heat transfer coefficient (U act ) as a function of the input, output and heat exchanger temperatures, the mass flow rate, specific heat value and surface area; nominal heat transfer co-efficient means for supplying a signal corresponding to a nominal heat transfer coefficient (U ava ); and a divider unit (61) connected to the actual heat transfer module (60) and the nominal heat transfer coefficient means for obtaining a ratio of the nominal to actual heat transfer coefficients which corresponds to the fouling factor (FF).
Claim 2
Dependent Claim
265 words
A performance monitor for generating a fouling factor of a heat exchanger having a heat exchange surface area against one side of which a heat exchange medium passes, the medium having a specific heat value, the performance monitor comprising: first temperature transmitter means (TT 1 ) for supplying a signal corresponding to an output temperature (T cold ) of heat exchange medium from the heat exchanger (10); second temperature transmitter means (TT 2 ) for supplying a signal corresponding to an input temperature (T hot ) of medium to the heat exchanger (10); third temperature transmitter means (TT 3 ) for supplying a signal corresponding to a temperature of the heat exchanger (10) on an opposite side of the heat exchange surface area; mass flow rate means for supplying a signal corresponding to a mass flow rate of medium through the heat exchanger (10); an actual heat transfer module (60) connected to the first, second and third temperature transmitter means (TT 1 , TT 2 , TT 3 ) and to the mass flow rate means for calculating an actual heat transfer coefficient (U act ) as a function of the input, output and heat exchanger temperatures, the mass flow rate, specific heat value and surface area; nominal heat transfer co-efficient means for supplying a signal corresponding to a nominal heat transfer coefficient (U ava ); and a divider unit (61) connected to the actual heat transfer module (60) and the nominal heat transfer coefficient means for obtaining a ratio of the nominal to actual heat transfer coefficients which corresponds to the fouling factor (FF).
Claim 3
Dependent Claim
137 words
A performance monitor according to claim 1, wherein the nominal heat transfer coefficient means comprises a heat exchange medium surface film module (30) for calculating a film coefficient of the heat exchange medium as a function of the input and output temperatures of the medium and a flow rate of the medium through the heat exchanger (10), the heat exchanger including a heat exchange fluid passing therethrough on the opposite side of the heat exchange surface area, a fluid surface film module (40) for calculating a film coefficient for the fluid as a function of the mass flow rate, the heat exchanger temperature and a flow rate of fluid through the heat exchanger, and an analytical heat transfer module (50) for calculating the nominal heat transfer coefficient as a function of the medium and fluid film coefficients.
Claim 4
Dependent Claim
128 words
A performance monitor according to claim 2, wherein said actual heat transfer module (60) comprises a plurality of difference units (63), a plurality of multiplication units (64, 65), a plurality of division units (66) and a natural logarithm function unit (61), all of said units being connected together to calculate the actual heat transfer coefficient for the heat exchanger according to the function: where: C p is the specific heat of the heat exchange medium, m w is the mass flow rate of the heat exchange medium, T hot is the input temperature of the medium, T cold is the output temperature of the medium, A is the heat exchange surface area, and T3 is the heat exchanger temperature on the opposite side of the heat exchange surface.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.