טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentReichel Mika
SubjectInvestigation and Simulations of a Hybrid Vapor
Compression and Liquid Desiccant A/C
DepartmentDepartment of Energy
Supervisor Professor Emeritus Gershon Grossman
Full Thesis textFull thesis text - English Version


Abstract

There is a great demand today for energy savings within the air-conditioning industry. A promising energy efficient alternative to conventional air-conditioning is liquid desiccant system (LDS). A hybrid vapor compression and liquid desiccant system includes both a liquid desiccant cycle and a vapor compression cycle. This system is capable of treating the temperature and humidity separately, by simultaneously cooling and dehumidifying air.

 The objective of this study has been to simulate several configurations of HVCLDS, optimize their performance and compare the HVCLDS to a conventional air-conditioning system. In the simulated HVCLDS the vapor compression cycle was used to remove heat from the dehumidifier of the LDS and reject it to the regenerator (desorber) of the LDS. The desiccant solution was cooled to a low temperature by the vapor compression cycle and was able to both cool and dehumidify the air.

Four configurations of HVCLDS have been modeled. For each configuration, several flow rates have been investigated and an optimal flow rate has been found. The coefficient of performance for the simulated HVCLDS was significantly higher compared to that of a conventional A/C system. It is found that it is important to consider parasitic losses from fans when designing the system. The coefficient of performance of the HVCLDS is increased if a water-cooled condenser is used or if there is a high flow rate of air in the regenerator. It is further found that it is necessary to simultaneously investigate several flow rates in order to find an optimal solution.