Liquid In Heat Exchanger Research Articles

Thermal Design Optimization of Shell-and-Tube Heat Exchanger Liquid to Liquid to Minimize Cost using Combination Bell-Delaware Method and Genetic Algorithm

Shell-and-tube heat exchanger is designed to satisfy certain requirements such as heat transfer capability, allowable pressure drop and limitation of size. Beside such requirements, it is important to consider economical point of view to get the lowest total cost. In this study, computational program and optimization for thermal design shell-and-tube heat exchanger were built for liquid to liquid with no phase change process in four variables design parameters using Bell-Delaware method. The design variables were tube size, tube length, baffle cut to shell inside diameter ratio and central baffle spacing to shell inside diameter ratio. The genetic algorithm was used as optimization method to get lower solution for economical point of view. The results from two study cases show that the genetic algorithm got lower total cost from the original design. The total cost decreased 28.83% in first study case and 52.56% in second study case from the original design.

Effect of air temperature non-uniformity on water–air heat exchanger thermal performance – Toward innovative control approach for energy consumption reduction

Parametric numerical analysis that explores the relation between the non-uniformity of air temperature distribution upstream of a heat exchanger and its thermal performance is performed. The obtained numerical results are employed toward the optimization of water–air heat exchanger thermal performance. Furthermore, the numerical results lay out the foundation to develop an innovative control approach for monitoring the airflow upstream of a cross-flow water–air heat exchanger that lead to the optimization of its thermal performance and energy consumption. Consequently, an in-house computational code is established to evaluate the aforementioned thermal performance based on known parameters; namely, distribution of upstream velocity and temperature of an air–liquid heat exchanger, the flow rate of heat exchanger liquid, in addition to the inlet liquid temperature. It was observed that non-uniformities in air temperature can, depending on the configuration, increase or decrease the thermal performance of a heat exchanger up to 5%. Additionally, controlling air temperature non-uniformities, the fuel consumption and carbon dioxide emission can be reduced by up to 0.97kg (1.34L) and 3.17kg respectively for a vehicle running three hours per day.

Parametric Analysis of Heat Exchanger Thermal Performance in Complex Geometries—Effect of Air Velocity and Water Flow Distributions

The thermal performance of automotive heat exchangers is greatly affected by the relationship that binds the nonuniformities in flow velocity and the distribution of upstream temperatures. Consequently, an in-house two-dimensional code is established to evaluate the thermal performance based on known parameters, namely, distribution of upstream velocity of an air–liquid heat exchanger, the flow rate of heat exchanger liquid, and the inlet air and liquid temperatures. A parametric research study is then performed to confirm the relation between the thermal performance of the heat exchanger and these different parameters. It was observed that nonuniformities in air velocity and water flow distributions decrease the thermal performance of a heat exchanger by up to 33 and 42%, respectively.

Neuro-fuzzy-based hybrid controller for stable temperature of liquid in heat exchanger

The liquid heating system is a temperature sustaining system which used to preserve the liquid temperature at a constant value at different temperature ranges. In this paper, neuro-fuzzy controller (NFC)-based control technique is proposed for achieving the desired liquid temperature. NFC is the combination of neural network (NN)-based controller and fuzzy logic controller (FLC). Initially, the error temperature and change of error temperature of a liquid heating system are determined. Then, the temperature variation is applied separately to FLC and NN-based controller. From the output of FLC and NN-based controller, the mean liquid temperature ratio of the condenser is calculated. Then based on the liquid temperature ratio, the automatic control valve (ACV) is adjusted till the desired temperature is reached. The proposed system is modelled in simulation platform and the output performances are evaluated. Then, the temperature stabilising performance of proposed controller is compared with FLC and ANN.