this paper presents a simple methodology for cost estimation of a near optimal heat exchanger network, which comprises mixed materials of construction. intraditional pinch technology and mathematical programming it is usually assumed that all heat exchangers in a network obey a single cost model. this implies that all heat exchangers  in a network are of the same type and use the same materials...

joule-thomson cooling systems are used in refrigeration processes such as cryogenic gas liquefaction. although extensive studies have been carried out by researchers, most of them include cryogenic heat exchangers and their associated fields. in the current study, an attempt was made to indicate the effect of using inappropriate operational conditions in a cryogenic joule-thomson cooling system...

In this study, the air-side pressure drop and heat transfer performance of plate-fin and microchannel coils were tested under clean and fouled conditions. The heat exchangers were tested with two different types of dust, ASHRAE dust and Arizona Road Test Dust. The ASHRAE dust was found to have a very significant impact on the pressure drop of the microchannel heat exchanger, increasing the air-...

In this study, the air-side pressure drop and heat transfer performance of plate-fin and microchannel coils were tested under clean and fouled conditions. The heat exchangers were tested with two different types of dust, ASHRAE Standard Dust and Arizona Road Test Dust. The ASHRAE dust was found to have a very significant impact on the pressure drop of the microchannel heat exchanger, increasing...

an investigation on the thermal performance of the soil as geothermal heat energy storage medium has been conducted. the thermal characteristics of the soil storage and the heat transfer from a heat exchanger in the soil, surrounding and bottom surface will be discussed. this investigation forms a contribution to a project to realize such storage to be charged from a solar heating system. this ...

An experimental study has been conducted to evaluate the performance of a compact round-tube louver-fin condenser, each with frontal areas of 0.25 m in both dry and wet conditions. Deluge water cooling is achieved by incorporating a perforated bottom plate-type water distributor on top of the round tube heat exchanger. Water is used as a refrigerant, and enters the heat exchanger tubes at 35°C ...

In air-cooling applications with frost production, heat exchanger performance is often air-side limited, because the two-phase flow of the refrigerant provides excellent heat transfer coefficients, and because designers typically use a large air-side fin spacing for frost tolerance. The large fin spacing prolongs operation of the heat exchanger by mitigating the effect of the accumulating frost...

With ever increasing concern on oil prices and energy conservation, there is a fast growing interest in hybrid vehicles globally. Currently, all hybrid vehicles, including micro, mild and full hybrids, adopt internal combustion engines which are inefficient in general. The corresponding waste heat of exhaust gas constitutes up to 40% of the fuel consumption. So, it is a pressing need for resear...

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...