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 ...

Abstract Energy crisis is a major challenge in the current world. Latent heat thermal energy storage (LHTES) systems are known as equipment with promising performance by which thermal energy can be recovered. In the present study a comprehensive theoretical and experimental investigation is performed on a LHTES system containing PEG1000 as phase change material (PCM). Discussed topics can be ca...

In this article, stream flow effectivness is based on hydraulic network studied in the shell-side of a shell and tube heat exchange as a case study. For an appropriate heat exchangers rating design to meet a specified duty, it's better to consider each stream flow separately. Using the hydraulic network principals, a set of the correlations for calculating different stream flow rates in the cro...

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...

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...

in this paper, overall heat transfer coefficient and friction factor of water based γ-al2o3 nanofluid in a double tube counter flow heat exchanger have been measured experimentally under turbulent flow condition. for better dispersion of γ-al2o3 nanoparticles in distilled water, magnetic stirrer and ultrasonic vibrator (with a power of 240 kw and frequency of 35 khz) were implemented. the stabi...