原位热脱附能效评价方法构建及应用研究

Assessment of Energy Efficiency of In-situ Thermal Desorption:Creation and Application

随着工业化和城市化的推进,土壤环境安全已成为我国面临的一个严峻问题。原位热脱附是实现场地快速、高效修复的技术之一,然而能耗高、成本大等缺点成为该技术广泛应用的“瓶颈”。目前国内外尚无统一的定量方法用于评价原位热脱附的能耗。在国外能耗分析的基础上,基于原位热脱附的工作原理和能耗计算模型,结合我国有机污染场地特征,构建了两种能耗评价方法,即污染物能效评价和污染土水体积能效评价。以华北某原位热脱附修复及其耦合化学氧化技术处理的工程项目为例开展能效评价,探讨两种能效评价方法的适用性。基于原位热脱附技术作用(含耦合化学氧化技术)能量受体的能耗分析结果表明,原位热脱附技术作用于土水加热的能耗占总能耗的61.80%~74.43%,而作用于污染物的能耗仅占2.11%~17.57%。考虑到热脱附技术能量受体的能耗分析结果和污染物量计算的不确定性,认为对于原位热脱附技术采用体积能效评价方法更有意义。污染土水体积能效评价结果表明,耦合区能效为7.91×10^(-6)m^(3)·kJ^(-1),而热脱附对照区能效为1.06×10^(-6)m^(3)·kJ^(-1),耦合化学氧化技术后的原位热脱附技术能效提升约6.5倍。

With the development of industrialization,soil environmental safety has become a serious matter in China.In-situ thermal desorption technology(ISTD)is one of the technologies with high remediation efficiency in short-term period.However,the high energy consumption and high cost become the"bottleneck"for its wide application.Currently,there is no unified quantitative method for evaluating the energy efficiency of in-situ thermal desorption,both home and abroad.To address this issue,energy efficiency evaluation method based on pollutants and energy efficiency evaluation method based on polluted soil/water volume were developed on the bases of the principle of in-situ thermal desorption and energy consumption calculation model of in-situ thermal desorption,as well as the characteristics of organic pollution sites in China.The applicability of these methods was explored through an engineering project involving in-situ thermal desorption and coupled chemical oxidation technology in North China.Based on the energy consumption analysis of the technology receptors(including coupled chemical oxidation technology),it was found that the energy consumption of in-situ thermal desorption applied to soil and water heating accounted for 61.80%to 74.43%of the total energy consumption,while the energy consumption applied to pollutants only accounted for 2.11%to 17.57%.To account for the uncertainty in the energy consumption analysis of thermal desorption technology and the calculation of pollutant amount,it is believed that using the volume energy efficiency evaluation method is more meaningful for in-situ thermal desorption technology.The results of the pollutant soil-water volume energy efficiency evaluation indicate that the energy efficiency of the coupled zone is 7.91×10^(-6)m^(3)·kJ^(-1),while that of the thermal desorption zone is 1.06×10^(-6)m^(3)·kJ^(-1).After coupling chemical oxidation technology,the energy efficiency of in-situ thermal desorption technology is increased by about 6.5 times.