ASME PTC 12.1
Closed Feedwater Heaters
|Publication Date:||29 December 2000|
This Code applies to all horizontal and vertical heaters except those with partial pass drain cooling zones. Designs with partial pass drain cooling zones are horizontal heaters with submerged drain cooling zones, and vertical channel-up heaters with drain cooling zones. In those designs, only a portion of the feedwater passes through the drain cooling zones; therefore, there are two feedwater flow streams with different temperature profiles.
A feedwater heater is designed to accomplish heat transfer between fluids. The heater design is based on a specific operating condition that includes flow, temperature, and pressure. This specific condition constitutes the design point that is found on the manufacture's feedwater heater specification sheet.
It is not feasible to expect that the test will be conducted at the design point. Therefore, it is necessary to predict the heater performance by adjusting the design parameters for the test conditions. Methods of calculating the predicted heater performance are presented in the Code. These predicted values shall then be compared to corresponding measured test values.