Work related to the first-principle modeling of a feedwater heater operating in a coal-fired power unit is presented, along with theoretical discussion concerning its structural simplifications, parameter estimation, and dynamical validation. The objectives of this work are as follows: (i) formulate and deploy a moderately complex first-principle model of a feedwater heater to reproduce operati...

Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. It is attributed to the formation of a very thin boundary layer at the absorber plate surface commonly known as viscous sub-la...

The solubility of fluorinated refrigerants in lubrication oil affects not only the stability performance of vapor compression refrigeration system, but also the safety control of start~up. It can cause oil foaming and reduction of viscosity, resulting in liquid slugging and improper lubrication. To void the deleterious effects, an oil heater is often used. But improper heater power can cause oi...

In this paper, we discuss the calibration procedure and performance of the poly-heater measurement technique for device characterization and reliability issues. We put a particular emphasis on the accessible temperature range, the heating and cooling dynamics, as well as on the impact of temperature gradient between the heater, device, and thermo chuck. In this context, the poly-heater techniqu...

Abstract—In the current study, energy and exergy analysis of a 65 MW steam power plant was carried out. This study investigated the effect of variations of overall conductance of the super heater on the performance of an existing steam power plant located in Derna, Libya. The performance of the power plant was estimated by a mathematical modelling which considers the off-design operating condit...

This study compares the performance of five electrical water heater models in the TRNSYS environment. The main capabilities, modeling assumptions and performance of the models are first assessed using an intermodel comparison. The main criteria for comparison are: domestic hot water supply temperature, power demand (time-dependent profile and overall energy use) and vertical temperature distrib...

Solar radiation is harnessed as an alternative energy source for numerous industrial and domestic applications. Currently, apart from space heating, air-conditioning lightning, solar water heating (SWH) systems have a widespread usage applications in both sectors. The major issue with that the transmission efficiency low so heat transfer augmentation methods can be used to improve thermal perfo...