Potential improvements of the Coefficient of Performance (COP) were investigated for R-407C at cooling and heating conditions of a residential heat pump. The study used CYCLE-11, a semi-theoretical vapor-compression cycle model, which was upgraded to simulate cross-flow, counter-flow, and parallel-flow evaporator and condenser with no restrictions on specifying superheated vapor and subcooled l...

In this paper, we present experimental investigation of convective heat transfer characteristic in the inner tube fluid of miniature concentric double tube Hair-pin heat exchanger with constant heat flux. This work is carried out for distilled water and a mixture of distilled water and ethylene glycol (10%, 20% and 25% by volume) as heat transfer cold fluid flowing in inner tube to carry away h...

The analytical solutions for the temperature variation of two streams in parallel flow, counter flow and cross-flow heat exchangers and related entropy generation due to heat exchange between the streams are presented. The analysis of limiting cases for the relative entropy generation is performed, and corresponding analytical expressions are given. The obtained results may be included in a mor...

Heat Transfer has special importance in engineering applications. So, researchers have suggested different new idea to increase heat transfer and using nanofluid is one of these methods In recent years, new methods have been used. One of these methods is the use of nanofluids, ., because nanofluids have higher heat transfer potential than base conventional fluids. In this investigation effect o...

In this work, the characteristics of flow and heat transfer of a fluid containing nano particles of aluminum oxide with the water volume fraction (0.1-0.2-0.3)(V/V) percent of the reports. The overall heat transfer coefficient, heat transfer and the average heat transfer fluid containing nano water - aluminum oxide in a horizontal double pipe counter flow heat exchanger under turbulent flow con...

1. The anatomy of the counter-current heat exchanger of skipjack tuna is described and the pattern of blood flow is analysed. 2. The pattern of blood flow is from the dorsal aorta, through the exchanger to segmental arteries to the tissues, from the tissues to segmental veins and back through the exchanger to the post-cardinal vein. 3. The vessels in the exchanger are about the same size as sys...

In this study, in order to increase the heat transfer rate in concentric double-pipe heat exchangers by an active method, a rotating ball valve was mounted downstream of the outer pipe end and used as a pulse generator. In the experimental set-up, hot water (40-70 °C) was passed through the inner pipe with fixed mass flow rate (Reynolds number ≈ 10,200) while cold water was passed through the a...

heat exchangers are the critical components of refrigeration and liquefaction processes. selection of appropriate operational conditions for cryogenic recuperative heat exchanger and expansion valve operating in joule-thomson cooling system results in improving the performance and efficiency. in the current study, a straightforward procedure is introduced to design an efficient joule-thomson co...