in this study. optimum allocation of heat transfer inventory for heat exchangers in a refrigeration system with specified power input or cooling capacity. and for a heat pump with specified heating capacity is investigated. the ratio of hot- to cold-end conductance unit cost ratio. g.was considered in the analysis as an additional variable of considerable importance to the designer summarized e...

A shell and tube heat exchanger is a class of heat exchanger designs seen most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher-pressure applications. As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle of tubes inside it. One fluid runs through the tubes, and another fluid flows...

this study represents effect of four variables in performance of a heat-pump in two cities of tehran and rasht. a computer program has been developed, simulating a certain heat pump acting in different environments with different refrigerants in heating season. the analysis is based on a homogeneous model. effect of different refrigerants, depth of the buried heat exchangers and moisture conten...

Performance was evaluated for a passive solar space heating system utilizing heat pipes to transfer heat through an insulated wall from an absorber outside the building to a storage tank inside the building. The one-directional, thermal diode heat transfer effect of heat pipes make them ideal for passive solar applications. Gains by the heat pipe are not lost during cloud cover or periods of lo...

fluids for various industrial applications because of their excellent thermal performance. this study analytically and experimentally examines the effects of nanoparticle dispersion on the entropy generation of eg–al2o3 nanofluid flows through a helical pipe as a heat exchanger under constant wall heat flux thermal boundary condition in laminar regime. it is found that adding nanoparticles impr...

In a Distributed Thermal Response Test (DTRT) the ground thermal conductivity and borehole thermal resistance are determined at many instances along the borehole. Here, such a test is carried out at a 260 m deep water filled energy well, equipped with a U-pipe borehole heat exchanger, containing an aqueous solution of ethanol as working fluid. Distributed temperature measurements are carried ou...

The goal of this study is to improve the thermal characteristics of high power LED (light-emitting diode) package using a flat heat pipe (FHP). The heat-release characteristics of high power LED package are analyzed and a novel flat heat pipe (FHP) cooling device for high power LED is developed. The thermal capabilities, including startup performance, temperature uniformity and thermal resistan...

This study presents a design method to fabricate a novel hybrid-structure flat plate heat pipe (NHSP heat pipe) for a concentrator photovoltaic. The NHSP heat pipe is composed of a flattened copper pipe and a sintered wick structure, and a coronary-stent-like rhombic copper mesh supports the structure. The coronary-stent-like supporting structure enhances the mechanical strength and shortens th...