Search

In many food processing plants, heat exchangers are an important component of complicated engineering systems involving heat transfer processes. A plate heat exchanger (PHE) is a crucial component of any condensing or evaporating system. The heat transfer and pressure drop are the most significant parts of sizing and grading the performance of PHE among many other aspects to consider. The flow is particularly turbulent because of the complicated corrugated surface design. As a result, empirical correlations are used to build plate heat exchangers, which deviates from reality. The performance of plate heat exchangers might be harmed when flow medium does not disperse uniformly. This in turn affects the pressure drop and heat transfer effectiveness. PHE is now widely used in a variety of industries, including chemical, food, and pharmaceutical processing, as well as in refrigeration plants. In the current study, however, PHE used in a soft drink production plant model is taken for investigation. Soft drinks are treated with preservatives to kill the bacteria and preserve the fluid for longer number of days. This work highlights the CFD application for the design of existing soft drink treating PHE in an industry. The parameters such as temperature distribution, heat flow, pressure and velocity variations with geometry and fluid velocities are investigated in detail. It was observed that an industrial PHE with 4 heat exchange plates can contribute for hot fluid temperature drop upto 17K at a flow circulation velocity of 0.125 cm/s. This also resulted in cold fluid temperature rise upto 14K. Cooling of fluids upto 60K can be achieved by increasing the number of zig-zag plates employed in PHE. It is also observed that heat transfer effectiveness can be improved by 20-25% by replacing existing finned tube heat exchangers with PHE's which is proposed to the industry where investigation is carried out. [ABSTRACT FROM AUTHOR]

A cooling tower is a heat rejection structure that releases waste heat into the atmosphere by lowering the temperature of a water stream. All heat-producing industries use cooling towers for cooling the water for re-circulation in the powerplant. The rectangular and circular cooling towers are the two widely used types employed in many industries. This work is focused on re-creating an induced draught cooling tower taken from industrial powerplant, which is circular in cross-section. A CFD analysis of cooling tower is carried out using ANSYS Fluent which is equipped with fan at the top allowing hot air to escape while pulling air throughout the cooling tower. The cooling tower performance was investigated in this study by calculating the effectiveness and evaporation capacities by varying air inlet angles. The cooling tower under consideration is re-created primarily for small scale industries. The modelling of the tower is done by considering industrial design aspects and dimensions taken from an existing thermal powerplant. The heat exchange that is taking place inside the cooling tower is visualized where temperature contours are studied carefully for various arrangements of air inlets. These arrangements are usually flat and inclined air inlets having inclinations at 30° with respect to vertical and horizontal axes. A cooling tower model with air inlet arranged at 30° inclined to both vertical and horizontal axes resulted in higher heat exchange rates with temperature drop of hot water upto 22°C. A validation with theoretically calculated evaporation capacities is made and comparison of the same is done. [ABSTRACT FROM AUTHOR]