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Solar energy is nearly an inexhaustible source of energy free of pollution and noise that can be used for different applications, whether domestic or industrial. Solar energy is divided into photovoltaic solar energy (Luque, 2011; Shanks, 2016; Sampaio, 2017; Zilli, 2018; Beltran.-Gonzalez, 2019; Pavlovic, 2020; Vasconcelos Sampaio, 2020) and solar thermal energy (Stutz, 2017; Mellor, 2018; Moudakkar, 2020). Photovoltaic solar energy is currently a commercially mature technology capable of generating and supplying electricity in the short or medium-term (Luque, 2011; Vasconcelos Sampaio, 2020). On the other hand, solar thermal energy is one of the most profitable renewable energy technologies and has a huge market potential worldwide. It represents about 90% of the installed solar capacity in the world and it is used for various purposes such as the generation of domestic hot water, heating and cooling (ESTIF, 2020). The installed storage capacity of solar heating energy in 2018 for Europe was 180.3 GWhth and a volume of 2,576,700 m3 (ESTIF, 2017; ESTIF, 2019). It is known that refrigeration has become indispensable at an industrial and domestic level, mainly for food preservation. Cooling from solar energy is not a new issue since 1977 the International Energy Agency (IEA) has launched the solar cooling program to promote technology and development in the field of refrigeration (IEA-SHC, 2020). Currently, there are conventional refrigeration systems, those that operate under refrigeration cycles such as steam-compression, absorption etc. On the other hand, there are prototypes that take advantage of the sun's energy, either with photovoltaic cells or with solar concentrators for their operation. However, these systems have failed to excel at a commercial level due to their low efficiency. Therefore, this work is based on the manufacture of a portable refrigeration prototype with the capacity to store 50 kg of fruit that uses photovoltaic solar energy and the adaptation of a Peltier cell system as an alternative to improve operating efficiency, given that its operation will be in isolated regions, where conventional electric power is not available.
Nowadays, the refrigerators are some of the devices with faster grow in technology and connectivity by means of Internet of Things IoT (Birje, 2017; Puri, 2020). The use of mobile applications APPs allow the remote monitoring of this kind of devices (Heard, 2018). The hyper-connectivity goes beyond of merely monitoring energy consumption and grant access to control other functions (Coli, 2019; Parashar, 2020). Energy consumption is closely related to the internal product kinds and their distribution (Sabegh, 2019; Albayati, 2020). Photovoltaic cells for refrigeration have being plentifully investigated, reported, used and simulated (Su, 2020).
In this work, a methodology that starts with the measurement and recording of real prototype geometries up to simulations to evaluate parameters, improvements or performance under various conditions is proposed. Here it is presented a case study of a solar-powered refrigerator with storage capacity for 50 kg of fruit. The refrigerator comprises two systems, vapor-compression and Peltier. The methodology consisted of acquiring by a 3D laser scanner or Coordinate Measuring Machine (CMM) and in some small complex, items using a 3D photogrammetry scanner (James, 2017; Ozdarici-Ok, 2015). These data were transferred first as a CAD or SolidWorks® geometry and subsequently transferred to domains geometry useful for ANSYS or COMSOL simulation software. These models with high-resolution bring the simulations closer to real prototypes. As a source of direct information from the prototypes, thermal images obtained using a thermographic camera were taken. Also, wireless sensors were installed for temperature and humidity monitoring. The analyses of the energy efficiencies of both prototypes were performed. The idea of presenting this methodology is to demonstrate that it is possible to apply it in various prototypes regardless of sizes, geometries or whether they are or not solar powered.
The work seeks to develop a hybrid cooling system based on a system of traditional compression system and a Peltier cooling system. The construction or production of this system is focused on being able to assist the agribusiness sector that is away from the public electric network, directly in the crop areas, proposing that this system will be powered completely by photovoltaic modules and in turn, be able to innovate with the cooling systems adaptations.