Analysis of open sorption and refrigeration humidity control systems

The production of conditioned air for process and comfort applications usually requires dehumidification of air during at least a portion of the year. In some situations, the dehumidification may be most economically accomplished with vapor compression or closed adsorption refrigeration equipment. In other situations, dehumidification with open sorption equipment utilizing natural cooling sources such as well water or cooling tower water may be most cost-effective. The situations in which dehumidification of air is the principal air conditioning requirement there does not exist any recognized procedure for making an accurate estimation of annual energy consumption.;In order to develop an analytical approach to estimating the annual energy consumption of liquid sorbent dehumidification system, mathematical models to predict the design as well as part-load performance of commercially available packed and coil type cooling and dehumidification systems were developed. An experimental investigation was also conducted to independently verify liquid sorption equipment manufacturer's claimed performance. The performance of liquid sorbent system as predicted by analytical model was found to be in good agreement with the experimental results.;Since a liquid system can not accomplish cooling and dehumidification of the air by itself, an external source of refrigeration water from a water chiller or cool water from a cooling tower has to be provided. Thus, performance evaluation models for cooling tower and water chiller were also developed as a part of the over-all system model.;Finally, computer algorithms for estimating annual energy consumption for two different liquid system application cases were developed. These algorithms are general in nature and can be used for any design configuration and application location.;An attempt was also made to identify the best alternate weather data format other than the hourly weather data to reduce the computation time. It was found that a dry bulb, humidity ratio, double bin format predicted the energy quantities which were in close agreement with the same energy quantities as gotten by hourly weather data.