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...

retrofit of heat exchanger networks for energy saving and/or debottlenecking is one of important aspects of process engineering. pinch technology, as the most efficient tool for the analysis of these networks, has been applied to hundreds of such projects and shown satisfactory results. however, all the existing methods for debottlenecking, using pinch technology, are either based on assumed he...

This study investigates the heat transfer performance of a novel ZA27 metal foam exchanger. An open-celled is combined with thin-walled copper tube in single-step casting process. The between two separated water streams flowing through and foam, respectively, measured compared to an equivalent shell exchanger arrangement. Heat enhancement up 71% rate exceeding 30 kW are observed attributed incr...

In the current work optimization of double pipe fin-pin heat exchanger has been studied. The effective parameters those are controlling the heat exchanger performance are divided in two categories; geometrical and operating conditions. Using the Brent’s optimization algorithm and handling the thermodynamically design concept, one can minimize entropy generation in different length of heat excha...

The effect of pulsation on the heat transfer rates, for turbulent water stream with upstream pulsation of different amplitudes, in a double-pipe heat exchanger for both parallel and counter flows, with cold water on the shell side, was investigated. Pulsation frequencies, with using a reciprocating device, ranged up to 260 cycles per minute (up to 4.3 Hz) and 5 different displacement amplitudes...

fridges are used in various industries, and heat exchanger is one of the main components of these systems; therefore, efficiency analysis of these systems is very important. in many fridges, frost over the heat exchanger tubes or pipes affects the system operation and reduces heat transfer between the refrigerant and ambient, so defrosting systems are usually used to enhance heat transfer. desi...

Symmetry in mathematical optimisation is of broad and current interest. In problem classes such as mixed-integer linear programming (MILP), equivalent solutions created by symmetric variables and constraints may combinatorially increase the search space. Identifying problem symmetries is an important step towards expediting tree-based algorithms such as branch-and-cut because computationally cl...

the objective of the present study is the synthesis of mwcnt-tio2 hybrid nanostructures by solvothermal synthesis method with ticl4 as precursor. the heat transfer enhancement due to the use of mwcnt-tio2 nanofluid was investigated. as-prepared hybrid materials were characterized by x-ray diffraction (xrd) and scanning electron microscopy (sem). the results showed that mwcnts were uniformly dec...

Microchannel heat exchangers (MCHXs) are now widely used in the HVAC&R industry. Similar to tube-fin heat exchangers used mainly in the indoor units, the innovative variable geometry microchannel heat exchanger will further reduce its compact size and enhance its performance. Variable geometry refers to a heat exchanger with different tube and fin surfaces within the same core with one or more ...

The paper is concerned with the thermodynamic analysis of a multi-stream heat exchanger system for Allam cycle and development regenerator flow chart. procedure are described in detail. constructed five double-flow exchangers has 2.5% lower power than ideal exchanging system. Besides, subsequent interaction principle transfer maximal amount proposed: it necessary to begin cooling heating flows ...