Desiccant Cooling System for Thermal
Comfort: A Review
HEMANT PARMAR
Department of Mechanical Engineering Ujjain Engineering College, Ujjain (M.P.)-India
D.A. HINDOLIYA
Deputy Registrar
Rajiv Gandhi Technological University, Bhopal (M.P.)-India Abstract
Desiccant cooling system (DCS) is alternate suitable option against conventional cooling system in humid climates. A typical system combines a dehumidifier that uses dry desiccant wheel, with direct or indirect evaporative systems and a sensible cooling system. DCS is the environmental protection technique for cooling purpose of the building. This system reduces the CFC level in the environment because it restricts the use of conventional refrigerant. In this paper, all the working principles and expected research areas have been discussed. Through detailed literature survey it has been observed that a desiccant cooling system may be a suitable option for thermal comfort in the climate where the humidity is higher. The desiccant cooling system (DCS) has proven their feasibility and cost saving in the field of air conditioning. This review provides a brief overview on the development of desiccant cooling system in different fields. Finally, concluding remarks regarding further development of desiccant cooling for thermal comfort are also provided. This technology is economically feasible and optimizes with low cost. This review is useful for making opportunities to further research in different areas of desiccant cooling system.
Keywords: Desiccant cooling system, Evaporative cooling, solar regeneration, Compounding of desiccant wheel, modeling of desiccant wheel.
1. Introduction
Desiccant cooling system is a suitable option in hot and humid climatic condition for thermal comfort. Vapour compression system has many drawbacks like it consume more power and increase the CFC level in the environment which depleting Ozone layer. For effective use of evaporative cooling techniques in humid climate, a desiccant material based rotary wheel can be utilized as a dehumidifier. In desiccant cooling technology, desiccant materials used as an adsorbent to absorb moisture present in out door air. In the region where the humidity is higher, the evaporative cooling is not effective. For the utilization of evaporative cooling more effectively, there is need of dehumidification of the air and again humidify the air to get required thermal comfort. The specific property of desiccant material is to absorb the moisture present in the air. The Fig.1 shows the basic desiccant cooling system suggested by many researchers-
Fig.1- Desiccant Cooling System
A B
C E
D N
M 1 1 1 1 1
G
T1 T2 T3 T4
T5
T6
T7
T8
T0
(A-Desiccant Dehumidifier, B-Energy conservation wheel for sensible cooling of process air, C, E-Direct evaporative cooler, D-space required to Conditioned,: M,N-Mixers of air ,G-Generator)
Various psychometric processes have been presented in Fig.2
1
2 3
4 R
0
DRY BULB TEMP. ( 0C)
ABS
.HUMIDITY
(K
g
/K
g
. of
dr
y
air
)
Fig.2 Processes of desiccant cooling system on psychometric chart
From the detailed literature survey, many research field of desiccant cooling technology has been observed and some important research fields are-
• Study of basic working principles of solid desiccant cooling system. • Parametric study of desiccant cooling system.
• Comparative study of different types of desiccant cooling system and desiccant wheel. • Solar assisted solid desiccant cooling system.
• Computer modeling of desiccant wheel.
• Computer modeling of desiccant cooling system (DCS) • Compounding of desiccant wheel.
• Application of DCS in the different fields.
2. Study of basic working principle of solid desiccant cooling system -
Development of desiccant technology started by Shelpuk and Hooker [1] (1979) under the scheme of US solar heating and cooling program. In the open cycle adsorption system, the basic operating principle of dehumidifier are explained and compared. Dhar et al [2] (1995) have been evaluated thermodynamic analysis of desiccant augmented evaporative cooling cycles for the Indian climatic conditions. They analyzed the different desiccant cooling cycles and suggested the most efficient cycle for Indian conditions.
Shen and Worek [3] (1996) suggested that a solid desiccant adsorber using 13X molecular sieve can be optimally designed on the basis of first law and second law of thermodynamics.
A modified version of the cross cooled desiccant bed is presented by Fathalah and Aly [4] (1996). The parallel flow channels are subdivided longitudinally and packed with silica gel particles instead of being glued to the side walls. The bed is regenerated utilizing the rejected heat from a LiBr-H20 absorption cooling machine and
both are integral in a solar powered air conditioning system. Two beds are alternatively working in the humidification/dehumidification cycle. A review study of adsorbents and adsorbates used in various investigations on solid – vapor adsorption heat pumps are presented by Shrivastava and Eames [5] (1988). Indirect evaporative cooler incorporated in Novel type desiccant cooling system by Belding et al [6] (1997). In the new system, the sensible heat wheel has been eliminated, resulting in a leak free heat exchange section without moving part.
and the R/P ratio (Reactivation air / process air). Results showed that the minimum reactivation temperature and minimum R/P ratio correspond to the smaller EMC.
A procedure is developed for the energy and exergy analysis of open cycle desiccant cooling system by Kanaglu et al [9] (2004) and this procedure is applied to an experimental unit operating in ventilation mode with natural Zeolite as the desiccant. The unit has a COP of 0.35, a reversible COP of 3.11 and an exergy efficiency of 11.1%. Desiccant wheel has the greatest percentage of total exergy destruction with 33.8% followed by heating system with 31.2%.
Daou et al [10] (2006) has been presented the feasibility of the desiccant cooling system in different climates is proven and the advantages it can offer in terms energy and cost savings are underscored. Some commented examples are presented to illustrate how the desiccant cooling can be a perfective supplement to other cooling systems such as traditional vapor compression air conditioning system, the evaporative cooling, and the chilled-ceiling radiant cooling.
The variation of heat of sorption with water loading is derived using Othrmer’s method by Goluboric and Hettiarachchi [11] (2006) and they found that heat of sorption can be up to 50% greater than the latent heat of vaporization.
A feasibility study of desiccant air-conditioning system performed by Hirunlabh et al [12] (2007)in Thailand. They conducted experiments with desiccant cooling system installed in a room of volume 76.8 m3. Under the test conditions, 95 cm bed thickness is recommended with a maximum adsorption rate of 473 g/h. The optimum percentage of air rates are as follows- 15% outdoor air, 15% return air and 70% of outdoor air mixed to the dry air leaving the desiccant. The corresponding electricity saving was about 4 yrs.
Panaras et al [13] (2007) proposed a methodology for the definition of the system’s achievable working range under specific set of space requirement. Through this approach, the system present greater potential for covering the space requirements, thus presenting more possibilities on a design basis, and more flexible control strategies, as well.
3. Parametric study of desiccant cooling system (DCS)
A parametric study of an open – cycle of adiabatic , solid desiccant cooling system analyzed by Charoensupaya and Worek [14] (1988). The effect of non-dimensional dehumidifier channel length, desiccant mass function and desiccant isotherm shapes are investigated. The result yield conditions for which the system has an optimum thermal coefficient of performance. Also described a mathematical model for the heat and mass transfer process that occurs during the sorption of water vapors in a dehumidifier consisting of a parallel channels lined on either side width desiccant felt, is presented. The model include both Gas–side and solid-side resistance for thermal and mass transfer. The effect of heat and mass transfer Biot numbers and other system parameters on the performance of an adiabatic open cycle cooling system are investigated.
Murali Krishna and Murthy [15] (1989) performed experiments on a silica gel rotary dehumidifier and found that process air governed by the ambient no. significantly influence the performance of the dehumidifier. Also decided the optimum value of rotational speed of desiccant wheel to operate at maximum capacity. Belding et al [16] (1996) analyzed and compared the aging curves for a new Type 1M desiccant developed specifically for desiccant cooling applications by LaRoche Industries Inc.
Yadav and Kaushik [17] (1991) studied on the vapor compression and solid/liquid desiccant hybrid solar space conditioning system. It is found that a hybrid system with desiccant cycle is more promising under high latent heat load and higher humidity conditions and significance energy saving can be achieved over standard vapor compression cooling system.
A psychometric chart is used for optimization of thermal swing desiccant wheel by Kadama A. et al [18] (2001). Mazzei et al [19] (2002) optimized the operating cost of desiccant cooling system by three software POWER DOE, DesiCal™ and DTPE. The operating cost of the desiccant system in summer Italian conditions, interesting saving up to 35% are obtained and reduced thermal cooling power up to 52% and pay back period of about 5-7 years.
Sand et al [20] (2002) developed a standard method of test (MOT) for packaged, solid desiccant based dehumidification system that is analogous to current procedure used for conventional packaged HVAC products. Latent, sensible and total system cooling capacity in BTU per hour is the proposed system performance parameter generated by the MOT. That is most familiar and ultimately useful to HVAC designers and system engineers.
were defined as operation parameters. Meanwhile coefficient of performance (COP) and cooling capacity of the system were called as the performance parameter. The system operation with a variety of experimental conditions resulted in an extensive data set covering the ranges of NRR, NDW, ma and TR as 5 rpm ≤ NRR ≤ 20
rpm, 0.1 rpm ≤ NDW ≤ 0.4 rpm, 0.05 Kg/s ≤ ma ≤ 0.139 Kg/s and 60 ºC ≤ TR ≤ 90 ºC respectively. A dimensional
analysis based on a trial and error procedure was followed to determine the functional relationship of COP and cooling capacity.
4. Comparative study of different types of desiccant cooling system and desiccant wheel
Aly et al [23] (1988) analyzed an integrated vapor compression and a waste heat dehumidifier air conditioning system. The drying matrix is regenerated entirely using the waste heat of the vapor compression unit by heat pump in a heat recovery system. The overall cooling COP achieved by the combined system reaches 1.73 for the designed conditions in Jedhah, Saudi Arabia, which is 25 % more than that of the vapor compression alone . Whenever the ARI conditions are applied, the combined system showed an overall COP of 1.76 with 27 % energy saving compared to vapor compression alone.
Jain et al [24] (1995) proposed various solid desiccant cycles for hot and humid climate and also evaluated the potential to get standard comfort conditions for 16 typical Indian cities. They found that amongst ventilation, recirculation and Dunkle cycle, Dunkle cycle is better for a wide range of outdoor conditions. Also compare the COP values of the cycle under Indian weather conditions with American Refrigeration conditions (ARI). This is, of course, mainly due to fact that here the outdoor moisture content is much higher (25 g/kg as against 15 g/kg in ARI conditions.
The potential evaluation of three cycles of desiccant cooling system i.e. Ventilation, Recirculation and Dunkle cycle described by Dhar et al [25] (1995). Psychometric evaluation of potential cycles for 16 typical Indian cities has been carried out with the objective of achieving standard comfort conditions in the room. The influence of various outdoor conditions, the effectiveness of the heat exchanger / evaporator coolers on the cooling coefficient of performance and volumetric air flow rate per unit cooling capacity have been investigated. It is found that amongst Ventilation, Recirculation and Dunkle cycle, the Dunkle cycle is better for wide range of outdoor conditions.
Neti and Wolfe [26] (2000) compared desiccant data by two theories from the literature i.e. method of characteristic appears to be good for only a small range of conditions. And the numerical approach appears to predict the trend well, through some time with the larger error.
A hybrid solar cooling system studied by Dai et al [27] (2002) and compared with solid adsorption refrigeration system alone and found that a new hybrid system performs better. Using some typical conditions, the COP of the system is greater than 0.4 and outlet temperature is less than 20 ºC.
Zhang and Niu [28] (2002) compared the performance of desiccant wheel and drawn the different processes on psychometric chart.
Vineyard et al [29] (2002) compared a desiccant system at two extreme ambient conditions. For both dry bulb inlet temperatures, the latent capacity significantly increased as desiccant wheel speed, face velocity and regeneration temperature increased. Tests at 80 ºF were found better because of higher partial pressure of water vapor at that temperature. This statement indicates that the performance of desiccant system is markedly improved at higher latent load conditions.
A feasibility study of using agriculture waste as desiccant for air conditioning system analyzed by Khedari et al [30] (2003). The natural fibers are to replace chemical desiccant such as Silica gel, molecular sieve etc.. The investigation was limited to coconut coir and durian peels. Experimental result confirmed that dry coconut coir and durian peels can absorb 30 g and 17 g H2 0per 100 g dry product, respectively, from air at the average
conditions of 32 ºC and 75% relative humidity. The optimum air flow rate is about 84 and 98 m3/hr-100g dry product respectively. Therefore the dry coconut coir is more suitable than the dry durian peels.
Jeong and Mumma [31] (2005) worked on two common desiccant materials i.e. Silica gel and molecular sieve on aluminum substrate. In this work, enthalpy wheel performance data generated using established fundamental enthalpy wheel models were statistically analyzed. And then first order linear regression equations were derived to estimate the enthalpy wheel sensible and latent effectiveness at normal operating rotational speed (over 20 rpm).
The properties of 13X, Silica gel, DH-5 and DH-7 absorbents proposed by Cui et al [32] (2005)in solid desiccant cooling system. The result showed that the properties of DH-5 and DH-7 adsorbents as desiccant cooling are superior to those of commonly used desiccant (Silica gel and 13 X molecular sieves) and the maximum adsorption capacity of water on DH-5 and DH-7 reaches 0.72 and 0.73 Kg/Kg respectively. The desiccant cooling capacity per mass unit of DH-5 is 1.9 times larger than that of 13X.
compared with the conventional vapor compression system, the hybrid desiccant cooling system economies 37.5 % electricity power when the process air temperature and relative humidity are maintained at 30 ºC, and 55% respectively.
5. Solar assisted solid desiccant cooling system
Solar energy may be utilized for regeneration of desiccant wheel. A solar air heater can provide the hot air at regeneration temperature to desiccant wheel. The basic arrangement of solar assisted desiccant cooling system presented in fig.3.
Solar radiations
Solar air heater
Desiccant Wheel
Air from regeneration side
Process air
Fig.3 Regeneration of desiccant wheel by solar energy
Jurinak and Backman [34] (1980) investigated the applicability of a number of such system in meeting residential cooling loads by dynamic simulation using the computer program TRANSYS.
Gershon and Johannsen [35] (1981) described the present state of art in solar cooling technology. A survey is given of the vast amount of research, development and engineering.
Sheriden and Mitchell [36] (1985) are developed a model on TRANSYS and it was found that for the two climate types considered and the high sensible load, the hybrid cycle uses 25-40% less energy over Jan. and July than a vapor compression unit.
Khalid and Shakir [37] (1987) investigated a solar assisted open adsorption cooling system has been designed and tested under the local conditions of Basrah, Iraq. Tests were carried out hourly from June to September 1984 with a directly supply of hot air from a corrugated absorber solar air heater for regeneration. Adsorption was carried out by a rotary disk of silica gel. Daily and seasonal coefficient of performance where obtained for the cooling system foe the mass flow rate employed.
Ismail et al [38] (1991) analyzed the performance of a solar regenerated open cycle desiccant bed grain cooling system. They performed experiments on simple to build solar regenerated open cycle grain cooling system. The device consists of 95.85 m2 collector coupled with two beds of silica gel. Results from a series of experiments suggest that the device may be used to cool up to 200 tonnes of grain. The electrical power consumption of the device is of the order of 0.3 watt per tonne of grain cooled and the total electrical energy consumption is of the order of 0.7 KWH per tonne of grain stored for a 6 months period. The solar cooling devices particular effective in tropical climates. An open inclined surface forced flow and brine still solar regenerators have been analytically modeled and a comparative assessment using a numerical model has been presented. The effects of various operating and climatic parameters on the water mass desorption rate for the given working fluid have been studied.
Desiccant appears to be well matched to the available solar resource in the Southwestern of U.S. and in the other two locations an auxiliary heat source is required.
Pesaran and Wipke [40] (1994) used an unglazed transpired solar collectors for desiccant cooling. Using computer model the performance of a desiccant cooling ventilation cycle integrated with either unglazed transpired collectors or conventional glazed fate plate collectors. It is found that the thermal coefficient of performance of the cooling system with unglazed collector was lower than that of the cooling system with glazed collectors because the former system did not use the heat of adsorption released during the dehumidification process. Although the area required for the unglazed collector array was 70% more than that required for the glazed
Collector array in a 10.56 KW solar cooling system, the cost of unglazed array was 45% less than cost of the glazed array.
Two different solar desiccant – dehumidification – regeneration system have been studied by Lu et al [41] (1995). Both have the same glazed area and utilize similar mechanisms for dehumidification and regeneration. The solid desiccant used in silica gel and the particles size range 6-8 and 2-4 mesh. A large potential are investigated in Taiwan.
Techajunta et al [42] (1999) presented an indoor and analytical study to evaluate the performance of a desiccant cooling system that uses a silica gel as desiccant, electric light bulbs to simulate solar radiations and forced flow of air through an integrated desiccant/collector. Comparisons between analytical calculations and experimental data show good agreement and calculations show that it should be possible to operate this system in tropical humid climates using the regeneration process in the day and the air dehumidification in the night time. Henning H.M. et al (2001) presented the potential of solar energy use in desiccant cooling cycles.
Khalid and Nabeel [43] (2001) evaluated the performance of solar assisted heat and desiccant cooling system for a domestic two storey residence located in Baghdad. A computer simulation was developed to assess the effects of various designs and operating conditions on the performance of the system and its components. The variable base degree -day method was employed in order to incorporate the hourly variations of solar heat gain and internal heat gains of the apace in the estimation of the heating load. The transfer function method was used to evaluate the hourly variations of cooling load. Only two collectors in series are applied to get the regeneration temperature i.e. 62 C at an air mass flux of 0.06 kg/s.m2 at mid day in July while a 36 C outlet temperature was achieved foe the same array and mass flux in Jan. The result of simulation of the solar air heating system indicated that the major design parameter is the collector area. The effect of air mass flux through the collector was not significant. Simulation study showed that the ambient temperature, regeneration temperature, heat exchanger effectiveness and evaporative cooler effectiveness have major influence on the system performance, whereas the dehumidifier has a minor effect.
Halliday et al [44] (2002) has been discussed the feasibility of using solar energy to power the desiccant cooling cycle and also presented a study, in which a solar desiccant cooling model is used to evaluate installations located in the southeast and east midlands of England, and in central Scotland.
Mavroudaki et al [45] (2002) evaluated the potential for solar powered single stage desiccant cooling in southern Europe. Study showed that solar desiccant cooling is feasible in parts of southern Europe, provided that the latent heat gains experienced are not excessive. However, if the relative humidity experienced is too high then desiccant cooling became impracticable simply because the regeneration temperature required is excessive. They also discussed the feasibility of using solar energy to power the desiccant cooling cycle in which a solar desiccant cooling model is used to evaluate installation located in the Southeast and east mid land of England and central Scotland.
Grossman et al [46] (2002) have been analyzed the current trends in solar powered air conditioning, which has seen renewed interest in recent years due to the growing awareness of global warming and other environmental problems. The principles of multi-staging absorption system are described. An economic comparison is provided which shows the total system cost to be dominated by the solar part of the system. A novel open-cycle (DER) system is described, which makes it possible to use the solar heat at relatively low temperatures, for producing both chilled water and cold, dehumidified air in variable quantities, as required by the load.
Ahmed et al [47] (2004) described the possibilities of using solar energy for reactivation of desiccant wheel in desiccant cooling system.
6. Computer modeling of desiccant wheel
A numerical model developed by Dini, and Worek [50] (1986) for the equilibrium sorption of isotherm of a silica gel matrix manufactured in the form of desiccant felt are experimentally determined as a function of temperature and relative humidity. Using the data, differential heat of sorption and the integral heat of wetting are calculated. Using the numerical model, the effect of variation in the equilibrium isotherm shape and the heat of sorption on the performance of the desiccant cooling system is also documented.
A mathematical model of desiccant wheel developed by Zhang H.F. et al [51] (1996), this model can be used to calculate the performance of stationary or rotary bed. The COP of an evaporator increased from 10-15 to greater than 30 by using new chemical refrigerant invented by Zu-She Liu.
Two modeling methods are used to evaluate the performance of desiccant wheel i.e. physical model and neural network model by Cejudo and Moreno [52] (2002).
Nia et al [53] (2006) proposed a model and simulate combined heat and mass transfer process that occur in a solid desiccant wheel is carried out with MATLAB Simulink. The solutions of the simulation at different conditions used in air dehumidifier have been investigated. This method is useful to study and modeling of solid desiccant dehumidification and cooling system. The modeling solutions are used to develop simple correlations for the outlet air conditions of humidity and temperature of air through the wheel as a function of the physical measurable input variables. These correlations will be used to simulate the desiccant cooling cycle in an HVAC system in order to define the year round efficiency.
Ge et al [54] (2007) reviewed the mathematical model for predicting rotary desiccant wheel. The models classified in to two categories -1) Gas-side resistance (GSR) 2.) Gas and Solid-side resistance (GSSR). They showed that GSSR higher in precision and more complex compared with GSR models.
7. Computer modeling of desiccant cooling system (DCS)
The performance of a desiccant, integrated, hybrid, Vapor compression cooling system is modeled numerically
by Worek and Moon [55] (1986). The hybrid system consists of 4 major components 1) Compressor 2) An
evaporator 3) Two desiccant , integrated condenser /dehumidifiers. They formed equations governing the transport of heat and mass in the desiccant system.
The performance of cooled bed dehumidifier, the principle components of the cooling system , is simulated using a numerical model by Majumdar and Worek [56] (1989). The numerical model is then used to investigate the performance of a cooled-bed cooling system, operating in recirculation mode, at variable indoor and outdoor conditions. The effect of regeneration temperature on the performance of the cooled-bed system is also documented.
Zhang et al [57] (2003) simulated a model of desiccant cooling system to improve the performance of desiccant wheel it is essential to accelerate the hump moving from the duct entrance to exit as soon as possible.
8. Compounding of desiccant wheel
The effectiveness of the desiccant wheel can be increase to make a composite desiccant wheel. A composite wheel can be absorbs more moisture than conventional desiccant wheel with same operating conditions. The unique feature of this type of desiccant wheel is that it can work under a lower regeneration temperature and have higher dehumidification capacity due to the contribution of the new compound desiccant material.
Dai et al [58] (2006) conducted experiments on compound desiccant wheel and found that the Novel desiccant wheel under practical operation can remove more moisture from the process air by about 20-40% over the desiccant wheel employing regular silica gel. The results are simulated and the simulation results showed that because of the use of the new compound desiccant, the desiccant cooling system can work under much lower regeneration temperature and have a relative high COP.
9. Application of DCS in the different fields
Solid desiccant cooling system can be used in different fields like buildings; restaurant etc. to get desired thermal conditions.
Zadpoor and Golshan [61] (2005) focused on power augment of a typical gas turbine by using a desiccant based evaporative cooling system. This technique requires a desiccant based dehumidifying process be used to direct the air through an evaporator cooler, which could be either media-based or spray type. They analyzed that this technique at least for hot and humid climate is more effective than other evaporative cooling techniques. Casos and Schmitz [62] (2005) proposed a desiccant assisted air conditioning system with geothermal energy for an office building in Hamburg, Germany. In this work, measurement results and investigation of the performance, energy demand and operating cost are presented. It was found that considerably primary energy saving can be achieved (70%) using desiccant air conditioning with borehole heat exchanger.
Madhiyanon and Adirekrut [63] (2007) coupled a desiccant wheel with a hot air drying system which is used to dry coconut pieces were better dry with desiccant wheel.
A desiccant cooling system was installed by Andersson et al [64] (2001) in Swedish office building and it was found that the efficiency of the system dependent on local climatic conditions, component performance and operating conditions. The dependence of the system performance on these three variables is presented as boundary lines on psychrometric charts to provide an easier understanding of the potentials and limitations of the system.
10. Conclusions from review study
The most important concluding remarks in this study are: Some desiccant cooling cycles have been analyzed and suggested a most efficient desiccant cooling cycle for selected climatic conditions. Direct and indirect evaporative cooling methods can be used for different cycles of desiccant cooling system. Many studies emphasized on the optimization of operating parameters and used exergetic manufacturing cost (EMC) method for deciding the minimum regeneration temperature and R/P ratio. The effect of different operating parameters on the performance of desiccant cooling system analysed and presented minimum running cost. Optimum wheel speed of about 17.5 rpm for high moisture removal and maximum COP. The R/P ratio, regeneration temperature, desiccant material, rotation of desiccant wheel, outdoor conditions etc. are the important parameters which affect the performance of desiccant wheel. The operating cost of the desiccant system in summer Italian conditions, interesting saving up to 35% are obtained and reduced thermal cooling power up to 52% and pay back period obtained about 5-7 years. Among the Ventilation, Recirculation and Dunkle cycle, the Dunkle cycle is better for wide range of outdoor conditions. Many studies evaluated the performance of different desiccant material and found the material which has the higher moisture adsorption capacity. Hybrid desiccant cooling system economies 37.5 % electricity power when the process air temperature and relative humidity are maintained at 30 ºC, and 55% respectively. Solar energy may be suitable option for regeneration of desiccant cooling system and it saves the regeneration power. Some studies stressed the energy saving potential by solar assisted desiccant cooling system. Mathematical modeling and simulation study of solar based desiccant cooling system performed by some researchers. A composite wheel can be absorbs more moisture than conventional desiccant wheel with same operating conditions. Compounding of desiccant wheel obtained the greater moisture adsorption rate. Some researchers applied the system in different fields and proved the feasibility of the DCS.
From the detailed review study the following are emerging research areas in the fields of desiccant cooling system-
1. Parametric analysis and sensitivity analysis of desiccant cooling system. 2. Hybrid desiccant cooling system.
3. Simulation and mathematical modeling of desiccant cooling dehumidifier. 4. Solar assisted desiccant cooling system.
5. Compounding of desiccant wheel. 6. Modeling of desiccant wheel.
References
[1] Shelpuk B.C. and Hooker D.W.,1979, “Development program in solar desiccant cooling for residential buildings”, International
Journal of Refrigeration,Vol.2, pp. 173 – 179.
[2] Dhar P.L, Kaushik S.C. and Jain S., 1995, “Thermodynamic analysis of desiccant – augmented evaporative cooling cycles for Indian
conditions”, ASHRAE Trans., Vol.101, pp. 735-749.
[3] Schen, C.M. and W.M. Worek, 1996. “ The second-law analysis of a recirculation cycle desiccant cooling system: Cosorption of water
vapor and carbon dioxide atmospheric environment”. 9:1429-1435.
[4] Fathlah K. and Aly S.E., 1996, “Study of a waste heat driven modified packed desiccant bed dehumidifier”, Energy Conservation and
Management, Vol. 37, pp. 457-471.
[5] Shrivastava, N., Eames, I.W., 1988. “ A review of the developments in solid vapor adsorption-refrigeration and heat pump system”. J.
of institute of energy, 485, December, pp 116-127.
[6] Belding W.A., and Delmas M.P.F., 1997, “Novel desiccant cooling system using indirect evaporative cooler”, ASHRAE Trans.,
Vol.103, pp. 841-847.
[7] Camargo J.R., E. Godoy Jr., C.D. Ebinuma,2005, “An Evaporative and desiccant cooling system foe air conditioning in humid
climates”, Journal of the Brazil Society of Mech. Sc. And Engg.,Vol.XXVII,No.3/243.
[8] Camargo J.R., Ebinuma C.D. and Silveira J.L., 2003, “Thermo economic analysis of an evaporative desiccant air conditioning
system”, Applied Thermal Engineering, Vol. 23, pp. 1537-1549.
[9] Kanoglu M., Carpinhoglu M.O. and Yildirim M., 2004, “Energy and exergy analysis of an experimental open cycle desiccant cooling
system”, Applied Thermal Engineering, Vol. 24, pp. 919-932.
[10] Daou K., Wang R.Z. and Xia Z.Z., 2006, “Desiccant cooling air conditioning: a review”, Renewable and Sustainable Energy Review,
Vol. 10, pp. 55-77.
[11] Goluboric M.N., Hettiarachchi H.D.M., 2006, “International Journal of Heat and Mass Transfer, Vol.49, pp. 2802-2809.
[12] Hirunlabh J.,Charoenwat R., Khedari J. and Teekasap S.,2007, “Feasibility study of desiccant air conditioning system in Thailand”,
Building and Environment Vol.42, pp. 572-577.
[13] Panaras G., Mathioulakis E., and Belessiotis V.,2007, “Achievable working range for solid all-desiccant air-conditioning system under
specific space comfort requirements”, Energy and Buildings,Vol.39, pp. 1055-1060.
[14] Charoensupaya, D. and Worek, W. M., 1988. "Effect of Adsorbent Heat and Mass Transfer Resistances on Performance of an
Open-Cycle Adiabatic Desiccant Cooling System," Heat Recovery Systems and CHP, 1988, Vol. 8, No. 6, pp. 537-548.
[15] Krishna and Murthy S.S., 1989, “Experiments on silica gel rotary dehumidifier”, Heat Recovery System and CHP, Vol.9, pp. 467-473.
[16] Belding W.A., Delmas M.P.F. and Holeman W.D., 1996, “Desiccant aging and its effects on desiccant cooling system performance”,
Applied thermal energy, Vol. 16, pp. 447-459.
[17] Yadav, Y.K., Kaushik, S.C., 1995. “ Psychrometric techno economic assessment and parametric studies of vapour compression and
solid/liquid desiccant hybrid solar space conditioning system”. Heat recovery system and CHP, Vol. 11, issue 6, 1991, pp 563-572.
[18] Kadama A. et al, 2001, “The use of phychrometric charts for the optimization of a thermal swing desiccant wheel” Applied Thermal
Engg., Vol.21, pp.1657-1674.
[19] Mazzei P., Minichiello F., Palma D,2002, “Desiccant HVAC systems for commercial buildings” Applied Thermal
Engg.,Vol.22,pp.545-560.
[20] Sand R., Fischer J.C., 2005. “ Active desiccant integration with packaged rooftop HVAC equipment”. Applied Thermal Engineering,
Vol. 25, pp 3138-3148.
[21] Subramanyam N., Maiya M.P.,Murthy S.S.,2004, “Application of desiccant wheel to control humidity in air conditioning system”,
Applied Thermal Engg., Vol.24,pp. 2277-2788.
[22] Carpinlioglu M., Yildirim M., 2005, “A methodology for the performance evaluation of an experimental desiccant cooling system”,
International Communication in Heat and Mass Transfer, Vol.32, pp. 1400-1410.
[23] Aly, S., Fathalah, K., 1988 “Combined absorption-desiccant solar powered air conditioning system” Wrne-und Stoffubertragung,
Vol.23, 111.
[24] Jain S., Dhar P.L., Kaushik S.C.,1995, “Evaluation of solid-desiccant-based evaporative cooling cycles for typical hot and humid
climates” International Journal of Refrigeration, Vol.18,pp.287-296.
[25] Dhar, P.L., Kaushik, S.C., Jain S. Pahwa, D. and Kumar Ravinder, (1995) ‘Thermodynamic analysis of desiccant augmented
evaporative cooling cycles for Indian conditions’, ASHRAE Transactions, V100, p735-749.
[26] Neti S.,Wolfe E.I.,2000, “Measurements of effectiveness in a silica gel rotary exchanger” Applied Thermal Engg., Vol.20,pp.309-322.
[27] Dai Y.Z., Wang R.Z., Xu Y.X., 2002, “Study of a solar powered solid adsorption-desiccant cooling system used for grain storage
system”, Vol.25, pp.457-430.
[28] Zhang L.Z., Niu J.L., 2002, “Performance comparisons of desiccant wheels for air dehumidifier and enthalpy recovery”, Applied
Thermal Engg., Vol.22, pp. 1347-1367.
[29] Vineyard E.A., James R.Sand, Durfee D.J.,2002, “Performance characteristics for a desiccant system at two extreme ambient
conditions” ASHRAE Transaction,Vol.108, pp. 587-596.
[30] Khedari J.,Rawangkul R.,Chimchavee W., Hirunlabh J., Watanasungsuit A., 2003 “Feasibility study of using agriculture waste as
desiccant for air conditioning system”, Renewable Energy, Vol.28, pp. 1617-1628.
[31] Jeong J.W., Mumma S.A., 2005, “Practical thermal performance correlations for molecular sieve and silica gel loaded enthalpy
wheel”, Applied Thermal Engg., Vol.25, pp. 719740.
[32] Cui Q.,Chen H., Tao G.,Yao H.,2005, “Performance study of new adsorbent for solid desiccant cooling”, Energy, Vol. 30, pp.
273-279.
[33] Jia C.X., Dai Y.J., Wang R.Z.,2006, “Experimental comparison of two honeycomb desiccant wheels fabricated with silica gel and
composite desiccant material”, Energy conversion and management, Vol. 47, pp. 2523-2534.
[34] J.J. Jurinak, J.W. Mitchell, J.W. Beckman, Open cycle desiccant air conditioning as an alternative to vapor compression cooling in
residential applications, in: Proceedings of the 5th Annual Conference on ASME Solar Energy Division, Orlando, FL, USA, 1983, pp. 374±381.
[35] Gershon Grossman and Alec Johannsen, 1981“Solar cooling and air conditioning”, Progress in Energy and Combustion Science, Vol.
7, Issue 3, 1981, pp. 185-228.
[36] Sheridan J.C., Mitchell J.W.,1985, “A hybrid solar desiccant cooling system”, Solar Energy,Vol.34,pp. 187-193.
[37] Khalid, A., Shakir, M., 1987 “ An experimental investigation in to a solar assisted desiccant-evaporative air conditioning system”.
[38] Ismail M.Z., Angus D.E., Thorpe G.R. (1991) “The performance of solar-regenerated open-cycle desiccant bed grain cooling system” Solar Energy, Volume 46, Issue 2, 1991, Pages 63-70.
[39] Smith, R.R., Hwang, C.C., Dougall, R.S., 1994. “ Modeling of solar assisted desiccant air conditioner for a residential building”.
Energy, Vol.19, pp 679-691.
[40] Pesaran and Wipke, 1992 “ Desiccant cooling using unglazed transpired solar collectors”. American Solar Energy Society annual
conference, June 1992.
[41] Lu, Sh.-M, Yan, W.-J., 1995 “ Development and experimental validation of a full scale solar desiccant enhanced radiative cooling
system”. J. of medical entomology, Vol.32, pp 859-863.
[42] Techajunta S. and Exell R.H.B.,1999, “Experiments in a solar simulator on solid desiccant regeneration air dehumidification for air
conditioning in a tropical humid climate”, Renewable energy, Vol. 17, pp. 549-568.
[43] Khalid, A., Nabeel, S.D., 2001. “Applications of solar assisted heating and desiccant cooling system for a domestic building”. Energy
Conversion and Management, Vol. 42, issue 8, pp 995-1022.
[44] Halliday S.P. et al, 2002, “The use of solar desiccant cooling in the UK: a feasibility study”, Applied Thermal Energy, Vol. 22, pp.
1327-1338.
[45] Mavroudaki P., Beggs C.B.,Sleigh P.A. and Halliday S.P., 2002 , “The potential for solar powered single-stage desiccant cooling in
Southern Europe”, Applied Thermal Engineering, Vol.22, pp. 1129-1140.
[46] Grossman G., 2002, “Solar-powered systems for cooling dehumidification and air conditioning”, Solar Energy, Vol. 72, pp. 53-62.
[47] Ahmed M.H., Kattab N.M., Fouad M.,2004, “Evaluation and optimization of solar desiccant wheel performance”, Renewable Energy,
Vol.30,pp. 305-325.
[48] Lie Mei et al, 2006, “Cooling potential of ventilated PV façade and solar air heater combined with a desiccant cooling machine”,
Renewable Energy, Vol.31, pp. 1265-1278.
[49] Henning H.M., 2007, “Solar assisted air conditioning of buildings-an overview”, Applied Thermal Engineering, Vol.27, pp.
2205-2212.
[50] Dini, S., Worek, W.M., 1986. “Sorption equilibrium of a solid desiccant felt and the effect of sorption properties on a cooled bed
desiccant cooling system” Heat recovery system, Vol. 6, issue 2, 1986, pp 151-167.
[51] Zhang H.F., Yu J.D. and Liu Z.S., 1996, “The research and development of the key components for desiccant cooling system”, Vol. 9,
pp. 653-656.
[52] Cejudo J.M., Moreno R., 2002, “Physical and neural network models of a silica gel desiccant wheel”, Energy and buildings, Vol.34,
pp. 837-844.
[53] Nia F.E. et al ,2006, “Modeling and simulation of desiccant wheel for air conditioning”, Energy and Buildings, Vol.38, pp. 1230-1239.
[54] Ge T.S., Li Y., Wang R.Z.,Dai Y.Z.,2007, “A review of a mathematical models for predicting rotary desiccant wheel”, Renewable and
Sustainable Energy Reviews, In Press.
[55] Worek, W.M., Moon, C.J., 1986. “ Simulation of an integrated hybrid desiccant vapour- Compression cooing system”. Energy,
Vol.11, issue 10, 1986, pp 1005-1021.
[56] Majumdar, P., Worek, W.M., 1989. “Performance of an open cycle desiccant cooling system using advanced desiccant matrices”. Heat
recovery and CHP, Vol.9, issue 4 pp 299-311.
[57] Zhang H.F. et al, 2003 “The research and development of the key components for desiccant cooling system” Renewable energy, Vol.9,
pp. 653-656.
[58] Dai, Y.J., Jia, C.X., Wu, J.Y., Wang, R.Z., 2006. “ Analysis on a hybrid desiccant air-conditioning system”. Applied thermal
engineering, Vol.26, issue 17, pp 2393-2400.
[59] Miller J.A.,Lowenstein A., James R. Sand,2002, “The performance of a desiccant-based air conditioner in a Florida school” ASHRAE
Transaction,Vol.108, pp. 575-586.
[60] Henderson, Hugh I. Jr., Adam C. Walburger, and James R. Sand, “The Impact of Desiccant Dehumidification on Classroom Humidity
Levels”, ASHRAE Trans. 2002, Vol. 108, Pt. 2, pp. HI-02-2-2.
[61] Zadpoor, A.B., Golshan, A.H., 2006 “ Performance improvement of a gas turbine cycle using desiccant based evaporative cooling
system”. Energy, Vol.31, issue 14, pp 2652-2664.
[62] Casos W., Schmitz G., 2005, “Experiences with a gas driven, desiccant assisted air conditioning system with geothermal energy for an
office building”, Energy and Buildings, Vol.37, pp. 493-501.
[63] Madhiyanon T., Adirekrut S., 2007, “Integration of a rotary desiccant wheel into a hot-air drying system: Drying performance and
product quality studies”, Chemical Engg. And Processing, Vol.49, pp. 282-290.
