Experimental Study Of Condensation Heat Transfer Characteristics Of Mixed Working Medium In Plate Heat Exchanger

Today the world is facing energy depletion, environmental pollution and other serious problems. Currently, to solve these problems what we can do is to save energy,reduce emissions and the development of clean energy, among them energy saving is extremely important. Industrial heat transfer is the general way of energy exchange,The energy exchange is done through heat exchange equipment, heat exchanger for short. Industrial heat exchanger is ubiquitous, its thermal efficiency in a direct impact on the effective utilization of energy.Plate heat exchanger is one of the most widely used heat exchanger at present,which is characterized by high heat transfer coefficient and heat transfer efficiency,small size,convenient installation and disassembly, and low investment cost.Marangoni effect is a method to improve condensation heat transfer by changing the form of vapor condenses. In this paper, the characteristic of Marangoni effect is combined to plate heat exchanger, and water-ethanol mixed vapor is condensated in plant heat exchanger, and formed Marangoni condensation. This kind of condensation can increase transfer efficiency, mainly the heat transfer coefficient.Built high air tightness experimental platform, and designed computer control system based on MCGS, and describes its build process and the design process.through condensation heat transfer experimental system studied experimentally the condensation of water-ethanol mixed steam in plate heat exchanger under various vapor pressures(31.2kPa, 47.4kPa, 84.5kPa) and different mass concentration of gas phase(0%, 1%, 2%, 5%, 10%, 20%). Under different condition,18 groups condensation heat transfer experiments have been made, and collected dates have been processed an calculated.Finally, experimental results show that, at the same concentration, the heat transfer coefficient of water-ethanol mixed vapor have been increased with theincrease of working pressure. In different working pressures, the heat transfer coefficient of 1% concentration of the gas phase is maximum, followed by 2%, 0%,5%, 10%, 20% descending order. Experiment verified that Marangoni effect can enhance heat transfer, he heat transfer coefficient of 1% is muche higher than pure steam(0%). At 84.5kPa working pressure, the overall heat transfer coefficient increases by 33%Experimental verification of the Marangoni effect can enhance heat transfer,mixing 1% vapor condensation heat transfer coefficient than that of pure steam(0%)is much higher when the condensation heat transfer coefficient, the working pressure of 84.5kPa, the overall heat transfer coefficient increases by 33% the total amount of increase in heat transfer coefficient with the cold side of the inlet and outlet temperature difference becomes smaller increases. The total amount of increase of heat transfer coefficient will be increased with the inlet and outlet temperature difference the cold side becomes smaller.