Internal radiation was investigated using the finite volume method for the heat exchanger method (HEM) growth of oxide crystals. Special attention was devoted to the temperature and thermal stress distributions in the bottom region of the grown crystal at the end of the solidification process. The numerical results show that internal radiation strongly strengthens heat transport through the cry...

This paper analyzes the performance of different controllers such as feedback, feedback plus feed-forward and internal model controller to regulate the temperature of outlet fluid of a shell and tube heat exchanger to a certain reference value. The transient performance and the error criteria of the controllers are analyzed and the best controller is found out. From the simulation results, it i...

The thermal performance of a heat exchanger is important for the potential application in an integrated solar cell/module and thermoelectric generator (TEG) system. Usually, the thermal performance of a heat exchanger for TEGs is analysed by using 1D heat conduction theory which ignores the detailed phenomena associated with thermo-hydraulics. In this paper, thermal and momentum transports in t...

Transient simulation of refrigeration systems is a relevant tool in the development and optimization of household refrigerators. These models should be accurate but fast. The core of transient refrigeration system simulation is the heat exchanger model as it imposes the system pressures. Dynamic pressure variation inside the heat exchanger is governed by the apparent density and internal energy...

In this study, the thermal performance of an internal heat exchanger-organic flash cycle system driven by geothermal water was investigated. The R600a/R601a mixtures were selected as working fluid. effects mole fraction on absorption capacity heater, temperature rise cold fluid in exchanger, net power output, efficiency, and electricity generation costs analyzed. outputs, costs, efficiency simp...

Increased concerns about climate change and day by day increment in energy cost has created the importance of Refrigeration & Air Conditioning system with high COP. COP of a Vapour Compression Refrigeration system is mainly influenced by the effectiveness of the Heat Exchanger being Employed. Optimization in the design of Heat Exchanger is highly desirable to improve their effectiveness and red...

An analytical model for a condenser with a wetted surface is developed by applying the governing conservations and rate equations and invoking the heat and mass transfer analogy. The heat exchanger is discretized in both the airflow and refrigerant-flow directions for a cross-flow configuration. Axial conduction along the tube walls is neglected and uniform distribution of water is assumed at t...

A nanofluid is mixture of nano sized particles and a base fluid. This paper investigates by using laboratory based double pipe heat exchanger model, the performance of nanofluid containing about 48.46nm  particle size nanoparticles (ZnO) without or with addition of nonionic surfactant Rokanol K7 (500ppm) into the base fluid double distilled water to prepared three different concentrations 1.0%,...