In air-conditioning and energy-recovery applications, heat exchangers are very important to the overall efficiency, cost, and size of the system. Current heat exchanger designs rely heavily on fin-and-tube or plate heat exchanger designs, often constructed using copper and aluminum. Recent developments in material sciencedin particular, advances in ceramics and ceramic matrix compositesdopen op...

Thermal response test (TRT) is an established method to determine design parameters for borehole heat exchanger (BHE) systems; borehole thermal resistance and effective ground thermal conductivity. Most commonly, these tests are performed with heat injection, using the same assumed power level as the planned BHE system. For a thorough description of TRT and current activities around the world, ...

Transcritical R744 (CO2) heat pumps are a low-GWP high-efficiency alternative for domestic hot water generation and space heating. For high set-point temperatures, however, the COP drops optimum operating pressure increases. this reason, effect on system performance achieved by inclusion of an Intermediate Heat Exchanger (IHX) is analyzed in depth. This carried out means numerical-experimental ...

In the presented paper two quality parameters are used to represent the state of a heat exchanger. The remaining lifetime can be estimated by trend regression. Also of interest is the uncertainty of the predicted lifetime which is determined by the confidence interval of the parameter estimation. These algorithms developed are used in this paper in an off-line evaluation of the measurements on ...

In the present study, the heat transfer coefficients of benzene in a spiral plate heat exchanger are investigated. The test section consists of a Plate of width 0.3150 m, thickness 0.001 m and Mean hydraulic diameter of 0.01 m. The mass flow rate of water (Hot fluid) is varying from 0.5 kg sec to 0.8 kg sec and the mass flow rate of benzene (cold fluid) varies from 0.4 kg sec to 0.7 kg sec. Exp...

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...

Heat exchangers are widely used in heating, air conditioning, refrigeration, industrial plants and refineries, gas processing and water treatment. Fouling is a chronic operating and design problem for retaining highly effective heat exchangers. This leads to countless chemical and mechanical attempts for reducing fouling. Mitigation of fouling and removal of deposits can be addressed efficientl...