(1) Solar refrigerator. The longest power supply time in household appliances is the refrigerator. For example, the use of solar refrigerators can greatly save energy and reduce emissions. The comparison between solar refrigerator and conventional refrigerator is shown in Figure 1. It can be seen from the figure that the solar refrigerator with common capacity is low-voltage 12/24V DC power supply. The input power of BCD-105 is only 50W, BCD-50 only 35W, and the daily power consumption is only 0.48kW·h or 0.38kW·h. Compared with the BCD-50, the ordinary Midea BC-45M refrigerator has a power of 250W, which is analogous to the daily power consumption, and the solar refrigerator has a very significant power saving effect.
(2) Combined use of solar energy and air-conditioning. Air conditioners are household appliances with high power and high power consumption. An air conditioning system that uses solar water heaters for heating and controlling thermal circulation is shown in Figure 2. Here is only an introduction to solar photovoltaic air conditioners (see Figure 3). It can be seen from Figure 3(a) that the air conditioning load peak is at noon on a sunny day in summer, and the peak area of solar power supply coincides with it, which can achieve the purpose of flat peak power load in summer. The principle block diagram of the solar energy system supporting the inverter air conditioner is shown in Figure 3(c). The input of the air-conditioning system is 110V AC, and it runs at 300W~1500W according to the set temperature. The additional solar system parameters are monocrystalline silicon solar panels 0.43m²/600W, the best working voltage is 100V, and a DC/DC boost chopper controller is also equipped to increase the input voltage from 100V to 250~320V and incorporate it into the DC of the air conditioner At the input end, the photovoltaic power generation power Ws is controlled to make the input voltage constant regardless of whether it is less than or greater than the air-conditioning load power PA. Measured at different times, when the sun is full, 600W of solar energy is added to the 1500W air conditioner, and it can save 50% of the electricity when heating or cooling.
(3) Solar direct drive air conditioner. The new type of solar air conditioner can actually be made simpler. As long as there is a low-voltage DC refrigeration system, it can be connected to a low-voltage DC solar system to make a solar air-conditioning system as shown in Figure 3(d).
(4) Semiconductor refrigeration and air conditioning. Semiconductor refrigeration and air conditioning are composed of semiconductor refrigeration fins (also called thermoelectric refrigeration fins). The structure principle of the semiconductor refrigeration sheet is shown in Figure 4(a). When the direct current passes through a galvanic couple formed by two different semiconductor materials in series, the two ends of the galvanic couple can absorb heat and release heat respectively, which can realize cooling or heating. Purpose, it is characterized by no moving parts and high reliability. It is made up of many N-type and P-type semiconductors in series and parallel, and the NP end is connected with a metal conductor to form a complete circuit. Finally, two ceramic sheets are clamped to form a hot flow cold end and a hot end. The temperature difference between the cold and hot ends can reach 40C~65C , If the hot end temperature is reduced by active heat dissipation, the cold end temperature will also drop accordingly. The main parameters of the semiconductor refrigeration sheet are: ceramic sheet size 1.8×3.4~62×62mm, height 5~8mm; current 0.8~60A, voltage 0.4~15.4V; cooling capacity 0.2~125W. Multiple semiconductor refrigeration fins can be connected in series and parallel to expand the capacity, as shown in Figure 4(b), and then combined with the electrical control system shown in Figure 4(c) to become various air-conditioning equipment as shown in Figure 3(d) and ( e) Used in various occasions, such as 4000W car air conditioner, 17kW (heating 26kW) passenger train air conditioner, and it is easy to transform into solar air conditioner.
At present, air-conditioning mattresses made with this principle will be an important new area of research and development for the development of supply-side economic products.
For more knowledge about solar energy applications, please refer to the previous article on this site, types and scales of solar photovoltaic power plants.