[雙語翻譯]空調(diào)系統(tǒng)設(shè)計外文翻譯--空調(diào)除濕轉(zhuǎn)輪的建模與仿真（英文）

1、Modeling and simulation of desiccant wheel for air conditioningFatemeh Esfandiari Nia a,*, Dolf van Paassen b,1, Mohamad Hassan Saidi a,2a Mechanical Engineering Department, Sharif University of Technology, Tehran 11365-

2、8639, Iran b Mechanical Maritime and Materials Engineering, Delft University of Technology, 2628 CD Delft, The NetherlandsReceived 29 January 2006; received in revised form 3 March 2006; accepted 4 March 2006AbstractThis

3、 paper presents the modeling of a desiccant wheel used for dehumidifying the ventilation air of an air-conditioning system. The simulation of the combined heat and mass transfer processes that occur in a solid desiccant

4、wheel is carried out with MATLAB Simulink. Using the numerical method, the performance of an adiabatic rotary dehumidifier is parametrically studied, and the optimal rotational speed is determined by examining the outlet

5、 adsorption-side humidity profiles. The solutions of the simulation at different conditions used in air dehumidifier have been investigated according to the previous published studies. The model is validated through comp

6、arison the simulated results with the published actual values of an experimental work. This method is useful to study and modelling of solid desiccant dehumidification and cooling system. The modeling solutions are used

7、to develop simple correlations for the outlet air conditions of humidity and temperature of air through the wheel as a function of the physically measurable input variables. These correlations will be used to simulate th

8、e desiccant cooling cycle in an HVAC system in order to define the year round efficiency. # 2006 Elsevier B.V. All rights reserved.Keywords: Desiccant; Adsorption; Cooling; Modeling; Simulation; Correlation1. Introductio

9、nIn desiccant cooling processes, fresh air is dehumidified and then sensibly and evaporatively cooled before being sent to the conditioned space. Since this technique works without conventional refrigerants, such as fluo

10、rocarbons and also since it allows the use of low-temperature heat (low-temperature industrial waste heat or solar energy) to drive the cooling cycle, it attracted increased attention especially in America, Japan, Europe

11、 and China [1]. Desiccants remove moisture from the surrounding air until they reach equilibrium with it. This moisture can be removed from the desiccant by heating it to temperatures around 60–90 8C and exposing it to a

12、 regenerative air stream. The desiccant is then cooled so that it can adsorb moisture again. Desiccant cooling cycles are particularly useful if they are used in humid regions. The major advantage of desiccant cooling is

13、 significant potential for energy savings and reduced consumption of fossilfuels. The electrical energy requirement can be very low comparing with conventional refrigeration systems. The source of thermal energy can be d

14、iverse (i.e., solar, waste heat, natural gas) [2]. Having low coefficient of performance (COP) can be considered as the main disadvantage for desiccant cooling systems. COP values of 0.8–1 are commonly predicted for this

15、 cycle. COP or coefficient of performance is defined as the space cooling load divided by thermal energy required to regenerate the desiccant. Some investigators use the heat removed from the processes air stream divided

16、 by the thermal energy required to regenerate the desiccant. Kang and Maclain-Cross [3] showed that the dehumidifier is the key component of a desiccant cooling system and the cooling COP (coefficient of performance) can

17、 be significantly improved by improving the performance of this component. Since the introduction of this technology, much research on the solid desiccant dehumidifiers has been accomplished. Maclaine-Cross and Banks [4]

18、 developed an analogy method for predicting the coupled heat and mass transfer process in desiccant dehumidifier wheel. Consecutively, Banks [5–7] analyzed the coupled heat and mass transfer processes in a porous medium

19、using a nonlinear analogy method and predicted the performance of a silica gel air dryer. Neti and Wolf have reported [8] that the analogy method appears to bewww.elsevier.com/locate/enbuildEnergy and Buildings 38 (2006)

20、 1230–1239* Corresponding author. Tel.: +31 15 2783115; fax: +31 15 2782460. E-mail address: F.Esfandiari@3ME.tudelft.nl (F.E. Nia). 1 Tel.: + 31 15 2786675; fax: + 31 15 2782460. 2 Tel.: + 98 21 6165522; fax: + 98 21 61

21、00002.0378-7788/$ – see front matter # 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.enbuild.2006.03.0209. the adsorption heat per kilogram of adsorbed water is constant; 10. the carry over between two air flows

22、is neglected.Based on the above assumptions, the model used in this analysis is transient and one-dimensional. One of the channels is divided into to a number of equal step discrete elements or channels as shown in Fig.

23、2. For each discritized channel that identified in Simulink model as a framework with inlet conditions for air and storing outputs and initial condition for solid, as shown in Fig. 2, the energy and mass conservation equ

24、ations can be written as follows. Mass transfer equation for the air stream:d?rgrv rg AgL?dt ¼ UgAgrgðvi ? voÞ þ hmAcðvs ? vÞ (1)dvdt ¼ Ug L ðvi ? voÞ þ hmAc rgAgL ð

25、vs ? vÞ¼ C1ðvi ? voÞ þ C2ðvs ? vÞ (2)wherev ¼ rv rg (3)Ac Ag ¼ 2LDh 2 (4)C1 ¼ Ug L (5)C2 ¼ hmAc rgLAg (6)Heat transfer equation for the air stream:dðrgAgLCgTg&#

26、222;dt ¼ rgUgAgCgðTgi ? TgoÞ þ hAcðTs ? TgÞ (7)dTg dt ¼ C1ðTgi ? TgoÞ þ C3ðTs ? TgÞ (8)C3 ¼ hAc rgLAgCg ; C3 ¼ Le C2 (9)Mass transfer equation for sol

27、id desiccant layer:dðrdwAdLÞdt ¼ hmAcðv ? vsÞ (10)where w is the water content of desiccant material,rvd rd ¼ w (11)Sodwdt ¼ hmAc rdAdL ðv ? vsÞ (12)For having the equations a

28、ccording to the variables vs, Ts v, T, it can be written asdw ¼ @w@’@’@vs dvs þ? @w@’@’@v þ @w@TS?dTs (13)ordw ¼ S1ðvs; TsÞdvs þ S2ðvs; TsÞdTs (14)S1ðvs; TsÞ ¼

29、@w@’@’@vs ; S2ðvs; TsÞ ¼? @w@’@’@Ts þ @w@Ts?(15)So mass transfer equation for desiccant layer will becomedvs dt ¼ ? S2ðvs; TsÞS1ðvs; TsÞdTs dt þ hmAc rdAdLS1ðvs; Ts&

30、#222; ðv ? vsÞ¼ ? S2ðvs; TsÞS1ðvs; TsÞdTs dt þ C4 S1ðvs; TsÞ ðv ? vsÞ (16)whereC4 ¼ hmAC rdLAd (17)Ac Ad ¼ 4DhLðDh þ dtÞ2 ? D2 h (18)hm

31、 ¼ hCg Le (19)and Le is Lewis number that here is assumed equal 1 for air stream.F.E. Nia et al. / Energy and Buildings 38 (2006) 1230–1239 1232Fig. 1. Desiccant wheel.Fig. 2. Schematic of descritization of one of t