In most domestic and commercial refrigeration systems, frost forms on the air-side surface of the air-to-refrigerant heat exchanger. Frost-tolerant designs typically employ a large fin spacing in order to delay the need for a defrost cycle. Unfortunately, this approach does not allow for a very high air-side heat transfer coefficient, and the performance of these heat exchangers is often air-si...

In this paper, a dynamic heat exchanger model that unifies the frosting and defrosting analyses is presented. A novel scheme is proposed to solve the air flow redistribution due to non-uniform frost blockage. Unlike the existing defrost models which separate analysis for tubes and fins, the proposed defrost model unifies the analysis to maintain model consistency. The first-principles based fro...

Heat transfer coefficient and thermal efficiency of γ-Al2O3/water nanofluids flowing through a double tube heat exchanger were experimentally investigated. The nanoparticles were well dispersed in distilled water at 0.05–0.15 %vol. A large number of experiments were performed at different fluid flow rates under turbulent flow regime (18,000<Re<40,000) and various nanofluid...

Heat Transfer has special importance in engineering applications. So, researchers have suggested different new idea to increase heat transfer and using nanofluid is one of these methods In recent years, new methods have been used. One of these methods is the use of nanofluids, ., because nanofluids have higher heat transfer potential than base conventional fluids. In this investigation effect o...

Air-cooled cross flow heat exchangers are very popular in the refrigeration and air conditioning industry. The fin type, tube arrangement, flow circuitry, and many geometry parameters, are to be designed and optimized. In this paper, a generic simulation and optimization tool for the design of air-cooled condensers/evaporators is introduced. It is featured with a user-friendly interface, freedo...

In the present era where energy demands are growing everyday it has become very important to capture every available energy from the hot source and utilize it for the process with minimum wastage. With this view, the combined serial two shell pass shell and tube heat exchanger (CSTSP) concept had been put forward and simulated using Fluent. Though the novel model of the heat exchanger has a hig...

Experimental investigations has been done to find out the heat transfer characteristics and friction factor of water based Al2O3 nanofluids as a coolant in  brazed plate heat exchanger. Plate heat exchanger either use horizontally or vertically. The base plate of the plate heat exchanger was kept inclined at (0⁰, 30⁰ ,60⁰, 90⁰). The experimentation have been done on the two different concentrat...