Mathematical design and performance investigation of evaporator water cooled storage‐cum‐mobile thermoelectric refrigerator for preservation of fruits and vegetables

Abstract

A storage-cum-mobile thermoelectric refrigeration system was designed for passive, active, and total load of refrigeration on the basis of thermo-physical properties of polyurethane sheet, heat generated by axial fan, and internal heat of commodities stored for refrigeration. A prototype of mobile thermoelectric refrigeration system of capacity 100 L (40 kg per batch) was designed and developed for maintaining the temperature of 15 ± 2 C and relative humidity of 80 ± 5%. The developed system of dimension (45  50  50 length  width  height), composed of four thermoelectric modules, liquid cooled evaporator, axial fan, diaphragm water pump, fogger, and water tank. The system was operated by 12 V DC power source. Results obtained from experimental performance evaluation indicated that 20.8 C temperature reduction was achieved in 210 min under no load operation, whereas, 23.6 C temperature reduction was obtained in 360 min when the system was loaded with 30 kg of bitter gourd. The temperature was reduced at the rate of 9.65 C/h till temperature of 20 C was attained which latter reduced to 2.23 C/h under no load condition, whereas, rate of temperature reduction was 7.44 C/h till attainment of 20 C and then reduced to 1.43 C/h under loading condition.The techno-economic feasibility of the system exhibited COP 0.85 which was significantly higher than those reported by several scientists in the range of 0.15-0.50. Developed refrigeration system can be effectively utilized as an eco-friendly technology for small scale cold storage of fruits and vegetables with causing detrimental effect to environment. Practical ApplicationsDeveloped thermoelectric refrigeration technology is climate friendly without generating any global warming potential and can be commercially used for small scale cold storage of fruits and vegetables to enhance the shelf life of produce. A developed refrigeration system is helpful for fruits and vegetable vendors to maintain the quality of commodity during transportation to minimize the decay of food and fetch good value to the commodity. | INTRODUCTIONThe principle of the refrigerated preservation of foods is to reduce and maintain the temperature of the food in order to control, reduce or stop the growth of microorganisms, ripening, browning reaction, pigment degradation, moisture loss and rate of deterioration of food (James & James, 2014). Food transport refrigeration is a critical link in the food chain not only in terms of maintaining the

Design and selection of solar‐powered Peltier‐based cooling neera (coconut sap) collecting system

“…The heat transfer coefficient of the refrigeration chamber and heat transfer through refrigeration chamber were calculated as follows (Chavan et al, 2021;Smith et al, 2002) The overall heat transfer coefficient of the cooling box,…”

“…The Peltier technology has been studied by many researchers (Nohay et al, 2020; Rokde et al, 2017; Varkute et al, 2016; Vijayarengan, 2018) related to the cooling system. The thermoelectric‐based refrigeration system was designed for small‐scale cold storage of fruits and vegetables and has been regarded as an environmentally beneficial technology without harming the environment (Chavan et al, 2021; Sitorus et al, 2020). The Peltier module's main restriction is that, depending on the electrical input and the thermoelectric material's quality, it can only be used at a specific temperature differential between the cold and hot sides (Abdul‐Wahab et al, 2009).…”

Performance Evaluation of Mobile Liquid Cooled Thermoelectric Refrigeration System for Storage-Cum-Transportation of Fruits and Vegetables

“…Efforts were also made by Ibikunle et al [24] for the development of a 30 W single-stage thermoelectric cooler of 4-litre capacity that cools the vegetables from 27 to 5 °C in 3 h. However, no evidence is available for the commercial use of thermoelectric refrigeration for the preservation of horticultural crops. Thus, in order to tackle the growing concern of food wastage due to the lack of scientific cold chain infrastructure for rural fruits and vegetable vendors and the simultaneous increasing demand for fresh fruits and vegetables, a thermoelectric refrigeration system was designed and developed [25]. The developed system has a larger storage capacity and a coefficient of performance (COP) of 0.85, which is higher as compared to other available systems.…”

“…Thus, in order to tackle the growing concern of food wastage due to the lack of scientific cold chain infrastructure for rural fruits and vegetable vendors and the simultaneous increasing demand for fresh fruits and vegetables, a thermoelectric refrigeration system was designed and developed [25]. The developed system has a larger storage capacity and a coefficient of performance (COP) of 0.85, which is higher as compared to other available systems.…”

Low‐cost inorganic phase change material improves the storage conditions of on‐farm storage chamber

“…Heat absorbed from inside, Q in (a) Initial heat load (Q initial ) = U Â A Â ΔT = 0.3985 Â 0.5863 Â (40 -30) = 2.34 W (b) Heat load due to respiration of the produce (Q Res ) Respiration rates of fruits and vegetables are generally expressed in terms of the rate of carbon dioxide (CO 2 ) production (mg CO 2 /kg/ h). Rate of CO 2 production of the vegetables under investigation at 20 C are determined from the literature as follows: Tomato = 35 mg CO 2 /kg/h (Watkins & Nock, 2012) Cauliflower = 79 mg CO 2 /kg/h (Watkins & Nock, 2012)Coriander = 300 mg CO 2 /kg/h(Xu, Shi, et al, 2019) Therefore, CO 2 production from 10 kg tomato, 8 kg cauliflower and 2 kg of coriander during 10 h was calculated to be, CO 2 production from tomato = 35 Â 10 Â 10 = 3500 mg CO 2 production from cauliflower = 79 Â 8 Â 10 = 6320 mg CO 2 production from coriander = 300 Â 2 Â 10 = 6000 mg Total CO 2 production = 15,820 mg However, 1 mg production of CO 2 produces 10.7 J of heat(Chavan et al, 2021)Therefore, heat produced due to respiration = 15,820 Â 10.7 = 169,274 J Rate of heat generation due to respiration ¼ 169274 10Â3600 ¼ 4:70W Total heat load = Q o + Q initial + Q Res = 4.67 + 2.34 + 4.70 = 11.71 W…”