Effect of three air supply modes on water evaporation process in limited space of frost-free refrigeratorEffet de trois modes d’alimentation en air sur le processus d’évaporation de l’eau dans l’espace limité d’un réfrigérateur à froid ventilé
Section snippets
Abbreviations
- ABA
annularly blowing air supply mode
- UBA
upward blowing air supply mode
- FBA
forward blowing air supply mode
Experimental setup
The water evaporation process inside the refrigerating compartment during on/off cycle was studied on a three-temperature frost-free refrigerator with single-evaporator. The tested refrigerator has a total volume of 345 L, divided into 193 L of refrigerating compartment (RC), 35 L of variable-temperature compartment (VC) and 117 L of freezing compartment (FC). There are five RC layers in the experimental refrigerator, in which the first three layers from top to bottom contain 4, 2 and 1 air
Model establishment and numerical settings
A RC model based on COMSOL was developed to investigate the water evaporation process. The physical model mainly includes RC three-layer space, which was composed of walls, air supply ports, shelves and water pans, as shown in Fig. 1. Concurrently, proper simplifications of the physical model were made: some tiny RC structures were removed, such as chamfering and fillets, the outer edge of the water pan etc. For the numerical research, following assumptions were made to simplify the analysis:
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Experimental results and model validation
The 24-h evaporated water mass of three RC layers was shown in Table 5. The results show that the evaporated water mass of R1 is the biggest with 37.5 g•24 h−1. And it is 9.5 g•24 h−1 and 12.2 g•24 h−1 higher than that of R2 and R3, respectively. The evaporated water mass of R2 is 28.0 g•24 h−1, slightly larger than that of R3.
Fig. 2 shows relative humidity and temperature curves of three RC layers during on/off cycle. During on cycle, the relative humidity of three layers decreases rapidly and
Conclusion
In this paper, the water evaporation process in a three-temperature frost-free refrigerator with single evaporator was investigated. And a RC model based on COMSOL was developed to study the water evaporation process caused by air forced convection. Then the effects of three air supply modes on the water evaporation rate of frost-free refrigerator were studied by numerical model. Detailed conclusion can be drawn as follows:
- (1)
During compressor-on cycle, the temperature of three layers decreased
Declaration of Competing Interest
I would like to declare that no conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication.
Acknowledgments
The research is supported by the National Natural Science Foundation of China [No.51876154] and Major Science and technology innovation engineering projects of Shandong Province [No. 2019JZZY020813].
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Water evaporation rate correlation based on Dalton model of enclosed space in frost-free refrigerator
2021, Case Studies in Thermal EngineeringCitation Excerpt :Therefore, it is necessary to find the upper edge of the moisture boundary layer. The calculation is carried out by COMSOL model in previous studies [42], and then the coordinates of the points are input into the post-processing to obtain the vapor partial pressure at different heights at the center of the water plate surface. The frost-free refrigerator model consists of three RC layers, named as R1, R2 and R3 from top to bottom respectively.