Research And Testing Experiment Of Thermal Parameters Of Shallow Layer Soil And Rock

Energy-saving and environmental protection in relation to the sustainability of the 21st century development of the national economy, two major issues. The whole world is committed to low-power, non-polluting, renewable energy projects of new technology research and application.At present, China is still based on coal-based developing countries, such an unreasonable energy structure has resulted in serious environmental pollution, and impeded the sustainable development of China's national economy. China's total energy consumption is currently building the community a large proportion of total energy consumption, about 1 / 3 the power consumption in commercial buildings and homes on the civilian. The relative shortage of energy in the current, particularly concern the construction of energy-saving technologies. In the field of air-conditioning and heating, as a clean and renewable energy, ground source heat pump system is the world's fastest-growing one of the ways.Ground Source Heat Pump (GSHP) for its energy-saving air-conditioning systems, environmental protection and sustainable development of all countries in the world and has been favored .In Europe and the United States have developed more mature in recent years in China's rapid development has been and is receiving increasing attention, both at home and abroad as a research study of workers in the field of eco-energy hot spot. Underground pipe-type ground source heat pump through the vertical or horizontal rock buried in the ground heat exchanger systems of heat exchange. At present the technology needs to be addressed two important issues are: to improve the heat exchange tube and heat transfer between soil, as well as to reduce the working fluid and the temperature difference between the soil, thereby enhancing the heat efficiency and lower initial investment. Reasonable system to pipe heat exchanger is designed to solve the above problems of the major route of transmission. Pipe heat exchanger in the system design process, the underground rock and soil physical properties of the average thermal design data is an important one of the guiding parameters.Ground Source Heat Pumps There are different forms and structures. According to the form of heat source can be divided into: ground source heat pump groundwater, surface water source heat pump and ground source heat pump. Geo heat pump in this article refers to ground source heat pump. It in accordance with the level of pipe can be divided into the vertical pipe and pipe-style. Which is the underground pipe heat exchanger can be divided into a single U-tube, multi-U-tube and pipe. Buried in the geothermal heat exchangers in the form of the many arrangements, vertical U-pipe pipe than other forms because of its many advantages have been widely used, is the current ground-source heat pump system, the mainstream form of pipe. In this paper, the object is a single vertical U-tube heat exchanger underground. It consists of four parts: U-tube, recycled water, to fill and the surrounding soil.In this paper, Jilin University, green energy research and development of ground-source heat pump laboratory experiment platform based on the combination of heat pump system for ground-source heat pump and thermal reaction tester to connect and establish a ground-source heat pump - thermal response test Instrument systems. The use of thermal reaction tester measurement of drilling were carried out cooling and heating tests of the two conditions.In this paper, Jilin University, green energy research and development of ground-source heat pump laboratory experiment platform based on the combination of heat pump system for ground-source heat pump and thermal reaction tester to connect and establish a ground-source heat pump - thermal response test Instrument systems. The use of thermal reaction tester measurement of drilling were carried out cooling and heating tests of the two conditions. Using line source model and source model column, combined with matlab software, heat transfer model will be the fluid temperature and the actual measured changes in fluid temperature contrast by adjusting the numerical heat transfer model, the average thermal properties of geotechnical parameters, when calculated temperature changes obtained with the measured temperature error of the hour, adjusting the thermal properties of the average value of parameters that is the result of the request.Paper also analyzes the initial ground temperature, ground heat, drilling diameter of the impact of thermal conductivity.Analysis results show that the radius of the initial drilling is to moderate the impact of its calculation of the main factors, the impact of rock and soil specific heat is very small, the basic can be ignored. Thus, in the design of ground source heat pump system, it is necessary to try to choose a good thermal conductivity properties of backfill materials, in order to enhance heat transfer and the surrounding soil;Construction, wherever possible the use of smaller diameter drilling in order to reduce thermal resistance;Cold regions in the north of the transition can be used in summer season or solar energy and other means to compensate for the ground temperature to increase the initial ground temperature, thus reducing the drilling depth, lower project investment.Application of thermal properties in geotechnical test drilling can easily determine the average rock and soil around the thermal conductivity and borehole thermal resistance, the parameters to be more in line with engineering practice, to the ground source heat pump system provides the basis for accurate design. In addition the use of movable thermal reaction tester can also be used for nation-wide parameters of the soil thermal properties testing, the establishment of a database of geothermal utilization, rational use of geothermal resources in China to reduce other energy consumption and environmental protection has important practical significance.