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...

many studies are performed by researchers about shell and tube heat exchanger but the multi-objective big bang-big crunch algorithm (mobba) technique has never been used in such studies. this paper presents application of thermal-economic multi-objective optimization of shell and tube heat exchanger using mobba. for optimal design of a shell and tube heat exchanger, it was first thermally model...

Single staggered is a design development of normal wire and tube heat exchanger that wires are welded with staggered configuration on two sides. Capacity of wire and tube heat exchanger is the ability of the heat exchanger to release heat. The objective of this study is to analyse the effect of wire pitch (pw) on capacity of single staggered wire and tube heat exchanger. The research...

The stationary monochromatic radiative transfer equation (RTE) is a partial differential transport equation stated on a five-dimensional phase space, the Cartesian product of physical and angular domain. We solve the RTE with a Galerkin FEM in physical space and collocation in angle, corresponding to a discrete ordinates method (DOM). To reduce the complexity of the problem and to avoid the “cu...

if an air flow is injected into a liquid fluid, many ambulant air bubbles are formed inside the fluid. air bubbles move inside the liquid fluid because of the buoyancy force, and the mobility of these air bubbles makes sizable commixture and turbulence inside the fluid. this mechanism was employed to enhance the heat transfer rate of a horizontal double pipe heat exchanger in this paper. howeve...

A generalized form of the ballistic-diffusive equations (BDEs) for approximate solution of the Boltzmann Transport equation (BTE) for phonons is formulated. The formulation presented here is new and general in the sense that, unlike previously published formulations of the BDE, it does not require a priori knowledge of the specific heat capacity of the material. Furthermore, it does not introdu...

The time-dependent equation of radiative transfer is solved for a participating medium housed in an axisymmetric cylindrical enclosure by both the discrete-ordinates method and the finite volume method. Many heat transfer processes, including absorption of renewable and sustainable solar energy in a solar receiving tube for use in power plants, can be modeled in a cylindrical enclosure. Steady-...

A shell and tube heat exchanger is a class of heat exchanger designs seen most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher-pressure applications. As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle of tubes inside it. One fluid runs through the tubes, and another fluid flows...

Three-dimensional numerical computations were carried out to understand the overlap effect of the transmitted pulses in a cubic participating medium subjected to a diffuse square pulse train using the transient discrete ordinates method with the pulse boundary condition. In concrete terms, the effects of the pulse width and pulse train interval on the divergence of radiative heat flux were scru...