A vertical geothermal probe consists of two or four polyethylene tubes U-shaped, used for circulating the coolant between the heat pump and the ground. It is installed in a deep borehole and sealed in a special grout, a kind of liquid cement, used to seal the borehole, and avoid the presence of air bags between the probe and the ground. Moreover, the grout provides a heat transfer medium betwee...

Heat exchangers are the most important equipment in refrigeration processes. Design and modeling of heat exchangers operating at low temperatures are different from other regular heat exchangers. This study includes two sections. In the first section, design and modeling considerations needed for evaluating the real thermal behavior of heat exchangers at low temperatures were discussed. The...

The aim of this work is to bring forward a new style heat exchanger about hollow fiber membrane module, and to analyze the performance which can expectantly be applied in the lithium bromide absorption refrigeration system. Polyvinylidene fluoride hollow fiber membrane module was adopted as the new style solution heat exchanger, hot feed solution from the generator flowed into the lumen side of...

With distributed power generation market, the most economical solution today is to generate power through small gas turbine systems, arbitrarily categorized as microturbines (5 – 200 kW) and miniturbines (200 – 500 kW). The thermal efficiency of such microturbines is about 20% or less if no recuperator is used in the system. Using a recuperator (regenerator can also be considered but has a numb...

Heat exchanger performance degrades rapidly during operation due to formation of deposits on heat transfer surfaces which ultimately reduces service life of the equipment. Due to scaling, product deteriorates which causes lack of proper heating. Chemistry of milk scaling is qualitatively understood and the mathematical models for fouling at low temperatures have been produced but the behavior o...

In the design of heat exchangers, it is necessary to determine the heat transfer rate between hot and cold fluids in order to calculate the overall heat transfer coefficient and the heat exchanger efficiency. Heat transfer rate can be determined by inverse methods. In this study, the unknown space-time dependent heat flux imposed on the wall of a heat exchanger internal tube is estimated by app...

This study focuses on the various experimental research analyses on performance of tubular heat exchangers the tubular heat exchanger is used throughout various industries because of its inexpensive cost and handiness when it comes to maintenance. In this paper we discus about tubular heat exchanger there are several thermal design factors that are to be taken into account when designing the tu...

in the present study, turbulent flow in channels of a plate heat exchanger with corrugated chevron plates has been simulated numerically using the commercial cfd package, fluent. unstructured mesh is used for discretizing the computational domain and simple algorithm is utilized to solve the pressure and velocity equations. there is a wide selection of different plate heat exchangers within the...