Research On The Performance Of Saturator Of HAT Cycle

HAT cycle is well known for environment-friendly performance and high thermal efficiency. As a key component in HAT cycle, saturator has important impact on the holistic performance of HAT cycle. So it has the necessity to do further study on saturator characteristics. So far, a little research job has been done focused on saturator, most of which are without packing. Even since structured packing was invented by Sulzer Company, it has been widely used in chemical industry field, because of its good property of fluid mechanics, mass and heat transfer and also reliability in high pressure and temperature environment. In this dissertation, metal structured packing is applied to the study of saturator, and the research job focuses on two aspects, theory and experiment.Firstly, the humid air model is founded based on the latest IAPWS IF-97 and real-state gas equation of air, which is applicable for high pressure condition. In the model, coefficient E is defined to evaluate the resistance in heat transfer between water and air. The critical model of saturator is also discussed, which means the air is saturated before the exit position. In this case, part of the vaporized water will condensed, so the control equations should be changed. Also, the characteristic of saturator is analyzed by a chart of equilibrium line and operation line. The simulation job of saturator is performed based on the founded model, in which the difference between Lewis factor and Lewis number and also the impact of the Lewis factor value on simulation results is discussed in details.Secondly, in the experiment, the characteristic of flux and spray cone of the nozzle is measured and analyzed. Two different kinds of packing, metal and plastic, is applied to evaluate the performance of the saturator. After comparison between the two, it can conclude that metal packing is better than plastic packing in all aspects, and more suitable for high pressure and temperature conditions. The equations of pressure drop and volumetric mass transfer coefficient of structured packing are presented based on experiment results. It is found that the ratio of water flux to air has vital influence on the saturator performance, the higher the ratio value the higher the parameters of outlet humid air, but at the some time the outlet water temperature will also become higher, which will decrease the effectiveness of saturator. In whole, the simulation results coincide well with the experiment results, except for some deviation at high ratio of water to air, because of the water fog carried in the outlet air. So it has the importance to foresee the carrying of water fog by outlet air at design stage.