Solar for air conditioner is divided into solar cooling and solar heating. Solar cooling refers to the use of solar energy to provide power to drive the refrigeration mechanism to extract cold energy, and ultimately achieve air conditioning in the buildings. While, solar heating uses solar energy to collect heat and directly or indirectly provides heat for the buildings.
There are two ways to realize solar for aircon:
(1) Solar photoelectric conversion, cooling by electric energy;
(2) Solar photothermal conversion, cooling by heat energy.
The cost of the former method is too high,based on the current price of photovoltaic cells, under the same cooling power, the cost is about 4 to 5 times higher than that of the latter. In addition to cooling, the second method can also provide heat at the same time, and the utilization rate of solar energy is higher. The application of solar air conditioner in the world is mainly the latter method.
There are two main types of thermal refrigeration products: one is absorption refrigeration, and the other is adsorption refrigeration. At present, these two types of products have been better integrated in scientific research and application. The COP of absorption refrigeration has reached more than 0.7, and the adsorption type has also reached more than 0.4.
(1) Solar absorption air conditioner
The system mainly includes absorption refrigerator, air conditioning box (or fan coil), solar collector, water storage tank, automatic control system and auxiliary heating system.
Principle description: The solar collector absorbs the heat of the sun to heat the water in the water tank, which is supplied to the refrigerator after the water in the water tank reaching the set temperature, and provides heat to the regenerator of the refrigerator to heat the dilute lithium bromide solution, so that the water in the dilute lithium bromide solution evaporates and changes back to the concentrated lithium bromide solution, then enters the absorber to absorb the evaporated water in the refrigeration process of the evaporator again, thus realizing continuous refrigeration through such a cycle.
(2) Solar adsorption air conditioner
1) Using natural working fluid water instead of freon, which will not produce greenhouse gases and will not destroy the ozone layer;
2) Using solar energy or low-grade waste heat to drive without electric energy, which is saving energy;
3) During normal operation, only water pump is needed, and the power performance coefficient can exceed 10;
4) It has few moving parts, no compressor, as well as reliable operation.