The paper presents two methods that are aimed at detecting fouling in cross-flow heat exchangers under normal operating conditions, using measurements that can easily be obtained, i.e. inlet and outlet temperatures and the mass flows of the hot and cold fluids. The methods are a) a physical method that is based on number of transfer units (NTU) relations and b) a black box model that is estimat...

The deterioration of the performance of a cross flow heat exchanger with condensation due to the longitudinal conduction was investigated. For a relatively small change of wall temperature along the flow directions which was shown to be common in many applications, the energy equations were solved numerically. An iterative method was used to solve the resulting equations of the finite differenc...

This paper first reviews non-traditional heat exchanger geometry, laser welding, practical issues with microchannel heat exchangers, and high effectiveness heat exchangers. Existing microchannel heat exchangers have low material costs, but high manufacturing costs. This paper presents a new expanded microchannel heat exchanger design and accompanying continuous manufacturing technique for poten...

In this paper, fluid flow and heat transfer in the laboratory (small size) shell tube heat exchanger are analysed by computational fluid dynamic software. In this type of shell tube heat exchanger baffles with different angles of rotation: 00 (horizontal segmental baffle), 150 (from horizontal), 300, 450, 600, 750, 900 (vertical segmental baffle) is used. Effect of baffle orientation on shell t...

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...

in this paper the effect of block shape vortex generators (vgs) on an air-water fin-tube heat exchanger has been studied experimentally using exergy analysis method. also the effect of these vgs on increasing heat transfer rate has been simulated numerically and the results show a good agreement with the experiments. in this research we used a wind tunnel to produce wind flow over heat exchange...

Fouling of heat exchangers is a severe problem in the industrialized world. The effects of fouling are reduced energy efficiency and increased greenhouse gas emissions. In fact, any heat transfer process has a risk of fouling on the heat transfer surface. The fouling can in some cases be cleaned physically, chemically or burned off; in other cases it may not be possible to clean the heat exchan...

in the presented research, heat transfer of a mobile electrolyte alkaline fuel cell (afc) (which the electrolyte has cooling role of system) has been considered. proper control volumes of system with specific qualification have been chosen. consequently, heat and mass transfer in control volumes have been assessed. considerations on them and contributed models lead to approve a double tube heat...

Joule-Thomson cooling systems are used in refrigeration and liquefaction processes. There are extensive studies on Joule-Thomson cryogenic systems, but most of them coverage steady state conditions or lack from experimental data. In the present work, transient thermal behavior of Joule-Thomson cooling system including counter current helically coiled tube in tube heat exchanger, expansion valve...