نمونه متن انگلیسی مقاله
For tunnels in cold or serious cold areas, the problem of leaking in the spring thawing period is very frequent, which will cause various tunnel diseases due to freezing. By using the surrounding rock geothermal energy in the tunnel project, especially the tunnel project below the permafrost layer, the cold area tunnel heat pump system is able to improve the overall heating energy efficiency as the side temperature regarding the heat pump evaporation increases, that furtherly serves the surrounding supporting building facilities. Inspired by this system and the active and passive coupling building technology, a heat recovery type of heat storage wall model is proposed in this research. By describing the heat transfer process regarding the heat recovery type of heat storage wall and carrying out the experimental research, its feasibility and effectiveness are verified. The results show that when the outdoor ambient temperature in Urumqi is −7~−15° C and the instantaneous total solar radiation reaches the range of 0~1108 W/m2 , this kind of wall can create hot wall-near air whose temperature is 11.89° C higher than the ambient temperature for providing a high-quality air heat source for the air source heat pump when the temperature is low, thereby significantly improving the air source heat pump heating system efficiency. Without the photovoltaic and photothermal equipment, the heat recovery type of heat storage wall can make the utilization rate of solar energy reach 13% to 20%, even up to 36%.
Due to the worsening world energy crisis, the use of renewable energy has drawn much attention, and its application in tunnel engineering in cold regions has emerged in an endless stream. Brandl  and Yuan et al.  applied ground source heat pump (GSHP) to tunnels in cold areas and improved the energy efficiency of GSHP by absorbing the geothermal energy of surrounding rocks, so as to serve the heating of tunnels and nearby buildings. Some scholars [3, 4] even found that the subway tunnel structure can obtain an annual average heat of 175 MWh and an annual average refrigeration capacity of 437 MWh.
This paper puts forward a new system which combines the passive technology (air source heat pump) and the active energy saving technology (Trombe wall). Through the analysis of the heat transfer process and the experimental results of this new heat recovery wall, some good conclusions are obtained.
(1) The thermal performance of the heat recovery type is significantly improved compared with that of the ordinary wall, which can remarkably lower the dissipated heat through the wall structure and reduce the heating energy consumption of the heating room. This shows that the new thermal recovery wall still retains the excellent thermal performance of the traditional Trombe wall
(2) When the fan runs at high speed and the instantaneous value of the total solar radiation reaches 0~1108W/m2 , the air interlayer of the heat recovery type of heat storage wall can provide a high-quality low-temperature air heat source with the largest temperature difference of 11.89° C between the inlet and outlet air. This part of the interlayer air with a higher temperature than the outdoor air can become a high-quality low-temperature air heat source of passive technology (air source heat pump), so as to greatly improve the energy efficiency of air source heat pump
(3) The heat recovery type of heat storage wall can achieve a 13% to 20% utilization rate of solar energy without relying on photovoltaic and photothermal equipment, and the maximum rate can reach 36%. The combined use of solar energy and air source heat pump will further improve the overall energy efficiency of the system
(4) Relying on the analysis on the heat transfer process regarding the heat recovery type of heat storage wall, strategies are put forward for improving the solar energy utilization rate: materials with high transmittance and low reflectivity are used for the lighttransmitting part and materials with high absorptivity are used for the heavy outer wall surface. In the following research, the system will be further optimized according to these strategies