scholarly journals Mathematical Model of Heating of Plane Porous Heat Exchanger of Heat Surface Cooling System in the Starting Mode

Author(s):  
V.I. Ryazhskikh ◽  
◽  
D.A. Konovalov ◽  
S.V. Dakhin ◽  
Yu.A. Bulygin ◽  
...  
2012 ◽  
Vol 229-231 ◽  
pp. 2122-2124 ◽  
Author(s):  
Abdulrahman A.A. Emhemed ◽  
Rosbi Bin Mamat ◽  
Dirman Hanafi

In manufacturing and industrial fields used heat exchanger to control of temperature weather as a boiler or cooling system. This system is not stable as the temperature output can easily disturb by noise and other disturbance such as surrounding temperature. To improve the heat exchanger system performance, the mathematical model‘s needed. The heat exchanger mathematical model in this case is constructed using dynamic modelling based on real parameters of the heat exchanger. The simulation result shows almost similar trend of responses with the experiment result, it means they are can used as a model of the heat exchanger.


Author(s):  
E.P. Parlyuk ◽  

It has been established that the cooling system of modern tractors and trucks can include 5 to 7 independent cooling circuits. A structural diagram of a modular cooling system for automotive engines and a mathematical model of thermal processes in a heat exchanger of the modular cooling system during machine operation are proposed. It is shown that the development of an algorithm for predicting and monitoring the state of the modular cooling system is possible based on a quantitative relationship between the rate of decrease in heat dissipation capacity and the duration of machine operation.


1982 ◽  
Vol 47 (2) ◽  
pp. 454-464 ◽  
Author(s):  
František Jiráček ◽  
Josef Horák

The effect has been studied of the inertia of the cooling system on the reliability of control of the temperature of the reaction mixture. The study has been made using a mathematical model of the batch reactor with an exothermic reaction. The temperature has been controlled by a two-level controller opening and closing the flow of the coolant. The aim of the control has been to maintain a constant value of the degree of utilization of the cooling capacity of the reactor. The instantaneous value of the degree of utilization has been assessed from the ratio of times for which the cooling system is idle to the time of operation. The reliability of control has been studied for variable activity of the catalyst.


Author(s):  
Seyyed Khandani ◽  
Himanshu Pokharna ◽  
Sridhar Machiroutu ◽  
Eric DiStefano

Remote heat pipe based heat exchanger cooling systems are becoming increasingly popular in cooling of notebook computers. In such cooling systems, one or more heat pipes transfer the heat from the more populated area to a location with sufficient space allowing the use of a heat exchanger for removal of the heat from the system. In analsysis of such systems, the temperature drop in the condenser section of the heat pipe is assumed negligible due to the nature of the condensation process. However, in testing of various systems, non linear longitudinal temperature drops in the heat pipe in the range of 2 to 15 °C, for different processor power and heat exchanger airflow, have been measured. Such temperature drops could cause higher condenser thermal resistance and result in lower overall heat exchanger performance. In fact the application of the conventional method of estimating the thermal performance, which does not consider such a nonlinear temperature variations, results in inaccurate design of the cooling system and requires unnecessarily higher safety factors to compensate for this inaccuracy. To address the problem, this paper offers a new analytical approach for modeling the heat pipe based heat exchanger performance under various operating conditions. The method can be used with any arbitrary condenser temperature variations. The results of the model show significant increase in heat exchanger thermal resistance when considering a non linear condenser temperature drop. The experimental data also verifies the result of the model with sufficient accuracy and therefore validates the application of this model in estimating the performance of these systems.   This paper was also originally published as part of the Proceedings of the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems.


2015 ◽  
Vol 787 ◽  
pp. 513-517 ◽  
Author(s):  
R. Pachaiyappan ◽  
R. Gopinath ◽  
S. Gopalakannan

Silicon carbides is a composite ceramic material produced from inorganic non-metallic substances, formed from the molten mass which solidifies on cooling and simultaneously matured by the action of heat. It is used in various applications such as grinding wheels, filtration of gases and water, absorption, catalyst supports, concentrated solar powers, thermoelectric conversion etc. The modern usage of silicon carbide is fabricated as a heat exchanger for high temperature applications. Leaving behind steel and aluminium, silicon carbide has an excellent temperature withstanding capability of 1425°C. It is resistant to corrosion and chemical erosion. Modern fusion reactors, Stirling cycle based gas turbines, evaporators in evaporative cooling system for air condition and generator in LiBr/H2O absorption chillers for air conditioning those systems heat transfer rate can be improved by replacing a present heat exchanger with silicon carbide heat exchanger. This review presents a detailed discussion about processing technique of such a silicon carbide. Modern known processing techniques are partial sintering, direct foaming, replica, sacrificial template and bonding techniques. The full potential of these materials can be achieved when properties are directed over specified application. While eyeing over full potential it is highly dependent on processing techniques.


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