This paper presents a simple methodology for cost estimation of a near optimal heat exchanger network, which comprises mixed materials of construction. Intraditional pinch technology and mathematical programming it is usually assumed that all heat exchangers in a network obey a single cost model. This implies that all heat exchangers  in a network are of the same type and use the same mate...

In the last few decades, heat exchanger networks have been widely adopted to recover thermal energy. Recently, mass exchanger networks have gained attention for recovering useful materials. By analogy, another class of exchanger networks, termed work exchanger networks (WEN’s), is conceivable for recovering mechanical energy. In the present work, the concept of the WEN is introduced. The WEN co...

abstract: in this study, al 2 o 3 /eg and tio 2 /eg nanofluids as coolants have been used in the double-tube heat exchanger. the hot solvent inlet heat exchanger must be cooled down with a specified amount. we can use nanofluids as coolants in the heat exchanger for optimization of the heat transfer area. therefore, the efficacy of nanofluids as coolants is verified. furthermore, flow rate of c...

For heat exchanger networks with stream splits, we present a simple way of controlling the split ratio. We introduce the “Jäschke Temperature”, which for a branch with one exchanger is defined as TJ = (T − T0)/(Th − T0), where T0 and T are the inlet and outlet temperatures of the split stream (usually cold), and Th is the inlet temperature of the other stream (usually hot). Assuming the heat tr...

The performance of the two types of vapor-injection (VI) cycles in a heat pump system is compared. The vaporinjection cycle using an internal heat exchanger (IHX) has a choice to select the branching point of the injection stream. The two VI cycles are different in terms of branching points of the injection stream. Different branching points of the injection stream influence the heating capacit...

The paper discusses optimal operation of a general heat exchanger network with given structure, heat exchanger areas and stream data including predefined disturbances. A formulation of the steady state optimization problem is developed, which is easily adapted to any heat exchanger network. Using this model periodically for optimization, the operating conditions that minimize utility cost are f...

The continued high cost of energy has mandated that the Chemical Process Industries reduce operational and capital costs through process heat integration. However, the heat integration of process streams can lead to process structures that are difficult to operate and control. This paper addresses the control of heat exchanger networks and it shows the importance of dynamic simulations in the s...

The paper presents an approach for robust PI controller design for a system affected by parametric uncertainty. The method is based on plotting the stability boundary locus in the plane of controller parameters that is called (kp, ki)-plane. Designed robust PI controller is implemented for control of two counter-current tubular heat exchangers in series with uncertain parameters, in which keros...

This paper describes a lithography-based microfabrication process developed for a recuperative heat exchanger intended for use in a cryosurgical probe. The probe, which uses the Joule-Thomson (JT) cooling cycle, must achieve a temperature < -50°C, with a freeze rate of 25-50°C/min. The heat exchanger must maintain high stream-to-stream thermal conductance while restricting parasitic stream-wise...

The single-phase flow and thermal performance of a double pipe heat exchanger are examined by experimental methods. The working fluid is water at atmospheric pressure. Temperature measurements at the inlet and outlet of the two streams and also at an intermediate point half way between the inlet and outlet is made, using copper-constantan thermocouple wires. Mass flow rates for each stream are ...