超市空调系统英文文献和中文翻译(5)

Fig。 3。 Isothermal surfaces at Tsup = 17 °C。

and the RAG have a little variation and maintains at about 61% and 87%, respectively。 However, as air temperature increases at con- stant relative humidity, the air moisture content increases。 In other words, it will lead to an increase of latent heat load or electricity consumption inputted into the VORDC。 Fig。 6 shows the variations of electricity consumption both of the HVAC and the VORDC with the DSAT。 When the DSAT increases from 16 °C to 19 °C, the

Fig。 4。 Temperature ﬁeld under different supply air temperature。

X。 Wu et al。 / International Journal of Heat and Mass Transfer 87 (2015) 685–692 689

Table 2

Temperature and relative humidity variations with Tsup。

Fig。 5。 Comparison of NIR for different supply air temperature, Tsup。

Fig。 8。 Comparison of products temperature on the second shelf for different Tsup。

The products temperature is a crucial parameter in controlling the hazard of bacterial development [32]。 In the VORDC, the major- ity of maximum temperature packs (97%) are located at the front of the cabinet, the largest number (60%) being at the front of the base论文网

of the cabinet [33]。 In this paper, the front products on the second

shelf are predicted in shelf-scale model。 The speciﬁc location of

(b)HVAC

Fig。 6。 Electricity consumption of HVAC and VORDC for different supply air temperature, Tsup。

electricity energy input in VORDC system increases 6。36%。 Meanwhile, as is described in Eq。 (8), the HVAC cooling load or electricity consumption decreases。

products is shown in Fig。 7。

From Fig。 8, it can be seen that the DSAT will obviously inﬂu- ence the products temperature。 When the supply air temperature increases from 16 °C to 19 °C, the maximum difference of products is 0。18 °C。 In addition, the temperature of products gradually increases from both sides to the middle due to the effects of exter- nal conditions of VORDC, as is shown in Fig。 9。

690 X。 Wu et al。 / International Journal of Heat and Mass Transfer 87 (2015) 685–692

Fig。 9。 Temperature ﬁeld at H = 0。92 m in shelf-scale model。

3。2。Inﬂuence of diffuser supply air velocity

As reported in other studies, the inﬁltration heat transfer rate is also related to the magnitude and the direction of ambient air velocity [2]。 Therefore, the inﬂuence of the DSAV of HVAC should be considered。 In the supermarket-scale simulations, it is found that there are two vortexes between air curtain of VORDC and air ﬂow from the diffusers, as is shown in Fig。 10。 At the interaction of the vortexes, the HVAC system will affect the ambient condition of VORDC。

Table 3 shows the inﬂuence of the DSAV of HVAC on the air temperature and humidity of measurement point and RAG of

VORDC。 From the results of supermarket and cabinet-scales computation, the temperature and relative humidity in the ambi-

ent conditions and at the RAG both decrease with the increase of air velocity from the diffusers due to its lower temperature and moisture content。 When the DSAV increases from 3。0 m/s to

3。5 m/s, the decline trend of the temperature and relative humidity is smaller or of no change。 The reason that, with the increase of DSAV (i。e。 provided cool capacity), the indoor air temperature will 超市空调系统英文文献和中文翻译(5):http://www.youerw.com/fanyi/lunwen_99302.html