| 84% of cold regions tunnels in our country are troubled by freezing injury problems.But most domestic freezing injury prevention measures are passive measures, and the running effect is poor,higher energy consumption,and so on.Linchang tunnel adopted new ground source heat pump system in experimental stage, it is more energy efficient compared with other heating antifreeze method.But there are a series of negative effects,such as it's operation effect and energy-saving effect is not stable,the high proportion of traditional energy consumption,damage to the underground geological structure,and so on.The average atmospheric temperature of plateau cold area in summer are above the freezing point and it's solar radiation is big, renewable,and high utilization efficiency,so property may be considered to take solar energy in summer for advantage to reduce the proportion of the traditional electric energy consumption in the system.This article is based on the Dabanshan tunnel located in Qinghai province, as it's year-round heating heat load of 21.5 kw.Taking the total heating load of Dabanshan tunnel for the reference to design it's antifreeze heating system.Using the heat storage of the soil in summer to increase the average temperature of soil and remove heat from the soil in Winter heating season.This paper designed two freeze protection systems correspond to cold regions tunnels:SGCHPES which takes heat build by laying bricks or stones in the early period of buried pipe in the centre of the tunnel surrounding rock and composite waterproof board, SGCHPES which takes hot section of buried pipe in the tunnel portal in the soil underground.For further research of the solar energy and ground source heat pump system, this topic established mathematical model of each part of the system by basing on the theoretical calculation.Then take TRNS YS for the platform to build solar energy-soil source heat pump system of the simulation model of each operation mode of the program and compared with traditional ground source heat pump system for simulation analysis.From the simulation results, we can see the surrounding temperature of the traditional solution of a ground source heat pump system at the start of the thermal simulation is 5.7?.After 20 years of system continue uninterrupted operation the minimum temperature of surrounding rock decreased to 5.1?, decreased by 0.6?,that is10.5%.Compared with the traditional ground source heat pump system, the source side inlet temperature of heat pump of the four new projects in heating season were outstanding increased by 0.6?,0.6?,2.9? and 0.6?.The average COP in heating season of heat pump significantly increased by 0.6,0.6,0.6 and 0.6 respectively.Meanwhile,the effect of the second option is most obvious.After 20 years of heat accumulation,the average soil temperature rise significantly, scheme 2 mode 1 and mode 2 respectively increased of 2.2? (27%) and 2.2? (27%).It means the heat accumulation effect is obvious.The four new plans has reduced the annual energy consumption of electricity, from 147.3 GJ of the traditional solution respectively decreased to 97.87 GJ,101.27 GJ,88.02 GJ and 87.91 GJ and reduced the traditional electricity in the proportion of energy consumption from 65% down to 53%,53%,57% and 53%,and increased the geothermal energy.solar energy and renewable energy proportion in total energy consumption.It's energy saving effect is obvious.The energy-saving effect of scheme two operating mode two is the most significant.In conclusion,to concern about the return water temperature variation tendency of the ground source side in the heat pump system,scheme two operation mode one is more favorable.As concern about raising COP value, geothermal heat balance and energy saving,scheme two operating mode two is the most optimal. |
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