Analysis of thermal effects in packed bed liquid desiccant dehumidifiers
Abstract An analysis of the performance of a packed bed liquid desiccant dehumidifier is presented. The enthalpy and material balance equations written over a differential height of the bed incorporate the effect of the heat of dilution of the desiccant liquid, the liquid—air interface temperature and the fraction of the evolved heat that is accounted for in the air stream. Numerical results obtained are discussed in terms of the physical and operating parameters of the system.
Development of new wire mesh packings for improving the performance of zero carryover spray tower
This paper presents the experimental results of chemical dehumidification of air by aqueous CaCl2 liquid desiccant. A new design of the spray tower for eliminating carryover without increasing the pressure drops has been done. New types of wire mesh packings have also been proposed for improving the performance of the conventional spray tower. Three different configurations of the wire mesh packings have been designed and tested to improve the performance of tower with least cost addition. Experimental results have been presented in terms of ’change in specific humidity’, rate of moisture removal and tower effectiveness. Comparison of the experimental results of towers using these three packings with the conventional spray tower show improvement in the performance of spray tower (∼30%) without mounting air side pressure drop burden. Mass flow rate of liquid desiccant, mass flow rate of air, inlet specific humidity of air, and concentration of desiccant solution are found to have major influence on the performance.
Effects of reservoir volume on performance of pulse tube cooler.
A pulse tube cooler has the advantages of long-life and low-vibration over conventional cryocoolers such as G-M and Stirling coolers because of the absence of moving parts at low temperature. On the other hand, the combination of a reservoir and orifice is indispensable to optimize the performance of pulse tube coolers. In order to make the pulse tube cooler compact for practical applications, the volume of reservoir should be minimized. This paper analyzes the effects of the reservoir volume on the thermodynamic performance of various components in a simple orifice and a double-inlet pulse tube cooler by combining a linearized model with a thermodynamic analysis. Expressions of entropy production for those components are presented. The results show that the reservoir volume has a significant influence on the entropy production in the various components when the reservoir to pulse tube volume ratio is smaller than about 5. The ratio is important to determine the minimum reservoir volume for a pulse tube cooler. Optimum settings for a double-inlet pulse tube cooler are also discussed.