Heat exchanger performance monitor

DETAILED DESCRIPTION The present inventon provides a monitoring system which has equivalent performance to prior art computer monitoring systems while costing less and being faster in operation.
Essentially the advantages of an analog device as well as a computer are combined in the present invention.
The invention comprises a plurality of individual function blocks which are structured and assembled to perform the same operations as a high cost computer.
The invention is applicable to heat exchangers such as pre-coolers, air coolers, evaporators and condensers, and also to other devices having heat transfer surfaces such as boilers, for the purpose of determining fouling and slagging.
The monitoring system of the invention can be used for example, to determine when a soot blowing operation should be commenced in a boiler.
Accordingly, an object of the invention is to provide 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, comprising first temperature transmitter means for supplying a signal corresponding to output temperature of the medium from the heat exchanger, second temperature transmitter means for supplying a signal corresponding to an input temperature of the medium to the heat exchanger, third temperature transmitter means for supplying a signal corresponding to a temperature of the heat exchanger on an opposite side of the heat exchange surface area and flow mass rate means for supplying a signal corresponding to the mass flow rate through the heat exchanger.
An actual heat transfer module is connected to the temperature transmitter means and the rate means for calculating an actual heat transfer coefficient as a function of the temperatures, mass flow rate, heat exchanger surface area and specific heat of the heat exchange medium.
The performance monitor also includes a nominal heat transfer coefficient mechanism which supplies a signal corresponding to the nominal or original heat transfer coefficient of the heat exchanger