Scemiconductor refrigeration, also known as thermoelectric refrigeration, is based on the Peltier effect of semiconductor thermoelectric materials directly into the electric energy into a temperature gradient of solid state active environmental protection refrigeration technology. Although the direct conversion of potential differences into temperature gradients was discovered by scientists in 1843, semiconductor thermoelectric devices were not commercialized until the 1960s due to the development of semiconductor materials. In recent years, with the improvement of refrigeration performance of semiconductor materials, semiconductor refrigeration is more and more widely used in household appliances, refrigerators, air conditioners, electronic equipment, medical equipment, military and other fields. Heat pipe semiconductor will also have a certain impact on water chiller.
At present, the research of semiconductor refrigeration mainly focuses on developing semiconductor thermoelectric materials with high coefficient of superior value and optimizing the structure of water chiller devices. It is of great significance to optimize the structure of semiconductor cooler, thermoelectric unit and working parameters from the aspect of thermodynamics while continuously improving the coefficient of material optimal value.
The research methods of semiconductor refrigeration are mainly divided into non-equilibrium thermodynamics and finite time thermodynamics. In the former, the heat source temperature is assumed to be equal to the endpoint temperature of the thermocouple, and the influence of external heat exchanger is not considered. Therefore, the conclusion obtained has certain limitations. In recent years, many scholars have analyzed and optimized semiconductor thermoelectric refrigeration devices based on the theory of finite time thermodynamics, which provides a new starting point for the optimization of practical thermal system.
As the core of the heat pipe, the capillary structure and size of the pipe directly determine the heat dissipation performance of the heat pipe. The two figures show the relationship between the refrigeration rate and refrigeration coefficient and the thickness of tube core and the length of condensing section when I=2.5A respectively. Before we do that, we need to know how to pipe water chiller.
It can be seen from the figure that both the refrigeration rate and the refrigeration coefficient decrease with the increase of the thickness of the tube core. This is because when the outer diameter of the heat pipe and the thickness of the shell are constant, the increase of the thickness of the tube core will lead to the decrease of the volume of the steam chamber, the flow of the thermal fluid is blocked, the heat transfer is worsened, and the heat cannot be transmitted from the evaporation section to the condensation section in a timely and effective manner, so the thickness of the tube core should not exceed 1mm.