基于温度效应的公路隧道运营通风模式优化
发布时间：2019-01-04 06:38
【摘要】：运营状态下的公路隧道通风系统是一个动态变化的体系。环境温度、车速以及交通量的变化,都会引起隧道内风压、风量的动态变化。在长大深埋公路隧道中,经常会碰到高地温,导致隧道热位差的变化,对通风系统造成影响,研究隧道以及竖(斜)井内风流温度场分布特征以及复杂隧道通风系统热位差的计算方法,进而有效利用热位差和交通风压,优化运营通风模式,达到节能降耗的目的尤为重要。本文通过国内外资料的收集、理论分析、数值模拟及风网计算等多重手段对高地温围岩与风流非稳态传热机理、多竖井隧道热位差计算方法以及风温、车速与交通量变化时隧道内风压、风量分布特征进行合理分析,并开展了以下研究工作:1.分析了隧道内风流温度变化的影响因素,探明了围岩与风流非稳态传热机理,建立了隧道纵向围岩与风流非稳态传热模型,推导了隧道纵向风流温度计算公式。采用模型计算某隧道纵向风温分布,并与现场测试结果对比,验证了隧道纵向围岩与风流非稳态传热模型的可靠性。2.研究了隧道送风井内空气自压缩热、围岩传热和水分蒸发引起的风流温度变化计算公式,建立了采用差分法计算送风井和排风井内风流温度的数学模型。3.分析了隧道内外风流温差引起的热位差作用机理,基于通风计算原理和连通器基本原理,提出热位差是重力场作用下空气柱重度差值引起的风压,提出采用空气柱重差法计算隧道内热位差,推导了热位差的计算公式,结合有限体积法软件Fluent对有纵坡隧道在空气柱重力作用下的风压风量分布特征进行分析,验证了基于空气柱重差法的热位差计算模型的可靠性。4.在fluent中建立相关网格模型,分析了环境温度变化对竖井集中排(送)风和分段式排送组合通风的影响,得出了不同环境温度、不同通风方式下隧道内、排风井和送风井内风流的速度、温度和密度分布特征,结合空气柱重差法分析了不同通风方式热位差的变化规律。5.提出采用计算空气柱容重结合风网解算的方法研究热位差和交通风压变化时隧道内风压风量分布特征,分析了隧道通风网络中风流的风量平衡定律、风压平衡定律和阻力定律,建立了隧道风网阻力模型和动力模型,包括通风阻力计算模型、风机风压计算模型、交通风压计算模型、自然风压计算模型、火风压计算模型和竖井送排式通风计算模型,以节点法作为基本算法,采用线性迭代计算方法,采用Visual C++语言编写了基于温度效应的隧道通风网络解算程序。6.依托秦岭终南山公路隧道工程,采用通风网络解算程序分析了不同环境温度、不同车速、不同交通量条件下隧道、排风井和送风井内风压风量分布特征。将计算结果与隧道需风量进行对比,提出了不同运营条件下的优化通风模式,可对隧道运营通风决策提供指导。
[Abstract]:The highway tunnel ventilation system is a dynamic system. The change of ambient temperature, speed and traffic volume will cause the dynamic change of wind pressure and air volume in tunnel. In long and deep buried highway tunnels, high ground temperature is often encountered, which results in the variation of tunnel heat potential difference, which has an impact on ventilation system. The distribution characteristics of air flow temperature field in tunnel and vertical (oblique) well and the calculation method of heat potential difference in complex tunnel ventilation system are studied, and the heat potential difference and traffic wind pressure are used effectively to optimize the operation ventilation mode. It is very important to achieve the goal of saving energy and reducing consumption. In this paper, the unsteady heat transfer mechanism of surrounding rock and air flow at high ground temperature, the calculation method of thermal potential difference of multi-shaft tunnel and the wind temperature are studied by means of collecting data, theoretical analysis, numerical simulation and wind net calculation. The distribution characteristics of wind pressure and wind volume in the tunnel are analyzed reasonably when the speed and traffic volume change. The following research work is carried out: 1. The influencing factors of air flow temperature change in tunnel are analyzed, the unsteady heat transfer mechanism of surrounding rock and air flow is proved, the model of tunnel longitudinal surrounding rock and air flow unsteady state heat transfer is established, and the calculation formula of tunnel longitudinal air flow temperature is deduced. The model is used to calculate the longitudinal wind temperature distribution of a tunnel, and compared with the field test results, the reliability of the tunnel longitudinal surrounding rock and wind flow unsteady heat transfer model is verified. 2. The formula of air flow temperature change caused by air self-compression heat, surrounding rock heat transfer and water evaporation in tunnel air supply well is studied, and a mathematical model for calculating air flow temperature in air supply well and exhaust air well by using difference method is established. The mechanism of thermal potential difference caused by air flow temperature difference inside and outside the tunnel is analyzed. Based on the principle of ventilation calculation and the basic principle of connectors, it is proposed that the thermal potential difference is the wind pressure caused by the heavy difference of air column under the action of gravity field. The air column weight difference method is used to calculate the thermal potential difference in the tunnel. The calculation formula of the thermal potential difference is derived, and the wind pressure and air volume distribution characteristics of the longitudinal slope tunnel under the action of air column gravity are analyzed in combination with the finite volume method software Fluent. The reliability of the thermal potential difference calculation model based on the air column weight difference method is verified. 4. 4. The related grid model is established in fluent, and the influence of ambient temperature change on the combined ventilation of centralized ventilation and segmental ventilation in shaft is analyzed. The results show that there are different ambient temperatures and different ventilation modes in the tunnel. The distribution characteristics of air flow velocity, temperature and density in exhaust and air supply wells are analyzed, and the variation law of heat potential difference in different ventilation modes is analyzed in combination with the air column weight difference method. 5. A method of calculating air column bulk density combined with wind network solution is proposed to study the distribution characteristics of wind pressure in tunnel when heat potential difference and traffic wind pressure change. The wind flow balance law, wind pressure balance law and resistance law in tunnel ventilation network are analyzed. The resistance model and dynamic model of tunnel wind network are established, including ventilation resistance calculation model, fan wind pressure calculation model, traffic wind pressure calculation model, natural wind pressure calculation model, fire wind pressure calculation model and shaft ventilation calculation model. The node method is taken as the basic algorithm, the linear iterative calculation method is adopted, and the program of tunnel ventilation network calculation based on temperature effect is written by Visual C language. 6. Based on the Qinling Zhongnanshan Highway Tunnel Project, the distribution characteristics of air pressure in tunnel, exhaust well and air supply well under different ambient temperature, different speed and different traffic volume are analyzed by using ventilation network calculation program. By comparing the calculated results with the air volume required by the tunnel, the optimal ventilation mode under different operating conditions is proposed, which can provide guidance for the ventilation decision of the tunnel operation.
【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U453.5
，
本文编号：2399921
[Abstract]:The highway tunnel ventilation system is a dynamic system. The change of ambient temperature, speed and traffic volume will cause the dynamic change of wind pressure and air volume in tunnel. In long and deep buried highway tunnels, high ground temperature is often encountered, which results in the variation of tunnel heat potential difference, which has an impact on ventilation system. The distribution characteristics of air flow temperature field in tunnel and vertical (oblique) well and the calculation method of heat potential difference in complex tunnel ventilation system are studied, and the heat potential difference and traffic wind pressure are used effectively to optimize the operation ventilation mode. It is very important to achieve the goal of saving energy and reducing consumption. In this paper, the unsteady heat transfer mechanism of surrounding rock and air flow at high ground temperature, the calculation method of thermal potential difference of multi-shaft tunnel and the wind temperature are studied by means of collecting data, theoretical analysis, numerical simulation and wind net calculation. The distribution characteristics of wind pressure and wind volume in the tunnel are analyzed reasonably when the speed and traffic volume change. The following research work is carried out: 1. The influencing factors of air flow temperature change in tunnel are analyzed, the unsteady heat transfer mechanism of surrounding rock and air flow is proved, the model of tunnel longitudinal surrounding rock and air flow unsteady state heat transfer is established, and the calculation formula of tunnel longitudinal air flow temperature is deduced. The model is used to calculate the longitudinal wind temperature distribution of a tunnel, and compared with the field test results, the reliability of the tunnel longitudinal surrounding rock and wind flow unsteady heat transfer model is verified. 2. The formula of air flow temperature change caused by air self-compression heat, surrounding rock heat transfer and water evaporation in tunnel air supply well is studied, and a mathematical model for calculating air flow temperature in air supply well and exhaust air well by using difference method is established. The mechanism of thermal potential difference caused by air flow temperature difference inside and outside the tunnel is analyzed. Based on the principle of ventilation calculation and the basic principle of connectors, it is proposed that the thermal potential difference is the wind pressure caused by the heavy difference of air column under the action of gravity field. The air column weight difference method is used to calculate the thermal potential difference in the tunnel. The calculation formula of the thermal potential difference is derived, and the wind pressure and air volume distribution characteristics of the longitudinal slope tunnel under the action of air column gravity are analyzed in combination with the finite volume method software Fluent. The reliability of the thermal potential difference calculation model based on the air column weight difference method is verified. 4. 4. The related grid model is established in fluent, and the influence of ambient temperature change on the combined ventilation of centralized ventilation and segmental ventilation in shaft is analyzed. The results show that there are different ambient temperatures and different ventilation modes in the tunnel. The distribution characteristics of air flow velocity, temperature and density in exhaust and air supply wells are analyzed, and the variation law of heat potential difference in different ventilation modes is analyzed in combination with the air column weight difference method. 5. A method of calculating air column bulk density combined with wind network solution is proposed to study the distribution characteristics of wind pressure in tunnel when heat potential difference and traffic wind pressure change. The wind flow balance law, wind pressure balance law and resistance law in tunnel ventilation network are analyzed. The resistance model and dynamic model of tunnel wind network are established, including ventilation resistance calculation model, fan wind pressure calculation model, traffic wind pressure calculation model, natural wind pressure calculation model, fire wind pressure calculation model and shaft ventilation calculation model. The node method is taken as the basic algorithm, the linear iterative calculation method is adopted, and the program of tunnel ventilation network calculation based on temperature effect is written by Visual C language. 6. Based on the Qinling Zhongnanshan Highway Tunnel Project, the distribution characteristics of air pressure in tunnel, exhaust well and air supply well under different ambient temperature, different speed and different traffic volume are analyzed by using ventilation network calculation program. By comparing the calculated results with the air volume required by the tunnel, the optimal ventilation mode under different operating conditions is proposed, which can provide guidance for the ventilation decision of the tunnel operation.
【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U453.5
，
本文编号：2399921
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