西安市地下水水源热泵空调运行情况调查与治理对策研究

通过对西安市地下水源热泵空调运行情况的调查,根据地下水源热泵开发及运营情况,分析了存在的一些实际问题,提出了一些建设性的意见。     

承德市水源热泵系统的现状与发展应用

文章系统阐述了水源热泵系统在承德市的应用现状和存在的问题。     

北京市污水源热泵发展潜力初探

水源热泵技术是一项新型可再生能源利用技术,主要用于建筑供暖和制冷,具有高效节能、环保、经济效益高等特点,优于传统锅炉供热和中央空调系统。其中,污水源热泵将城市污水、再生水等作为水源,充分利用其储存的冷热能量,进一步节约了水资源。污水源热泵在北京市具有推广条件,对此进行了初步可行性分析,并探讨了发展潜力。     

安阳市地下水源热泵的现状与应用

地下水源热泵是一种通过抽取地下水,利用地下浅层地热资源,既可供热又可制冷的高效节能空调系统。它具有环保、洁净、节能、经济的特点。安阳市自2001年引入水源热泵后,发展迅速。本文系统阐述了水源热泵在安阳市的应用和存在的问题。     

浅谈地下水水源热泵建设项目水资源论证

地下水水源热泵是一种环保节能新技术，为了更好地发挥其优势，实行最严格水资源管理制度，本文提出地下水水源热泵建设项目水资源论证的主要内容及报告书编制时需注意的问题。     

安阳市发展地下水源热泵空调的可行性分析

本文通过对安阳市水文地质条件、地下水源热泵投资运行成本、国家扶持政策和回灌水对地下水的影响等几个方面,详细分析了发展地下水源热泵空调的可行性,并针对推广过程中所发现的问题,提出了适合地下水源热泵发展的合理化建议,为水行政主管部门审批管理和地下水资源合理开发、有效保护提供科学依据。     

我国地下水源热泵应用现状和监管措施探讨

近年，在国家宏观政策指引和地方政府大力扶持下，地下水源热泵工程数量持续、快速增加。由于缺乏有效的监督和管理，许多工程逐渐暴露出一些问题。在了解地下水源热泵技术原理、特点的基础上，根据国内外地下水源热泵技术应用现状．分析了我国地下水源热泵工程管理中存在的主要问题，提出了加强我国地下水源热泵工程监管的建议。     

水源热泵空调技术应用中的地下水资源的保护

水源热泵技术是利用地下水中吸收的太阳能和地热能而形成的低温低位热能资源，并采用热泵原理，通过少量的高位电能输入，实现低位热能向高位热能转移的一种技术。     

南通市地下水源热泵应用研究

0引言地下水源热泵作为一种高效节能、既可供暖又可制冷的空调系统,具有清洁环保、低污染、低运行成本的显著特点,在能源日益受到关注的今天,有着广阔的发展空间。     

安阳市浅层地下水再利用回灌对地下水的影响

利用安阳市水源热泵空调系统监测数据,分析了浅层地下水再利用回灌对地下水的影响。地下水水质、地下水温度场及地下水水位的分析结果表明,目前安阳市浅层地下水再利用回灌未对地下环境造成明显不利影响。     

地源热泵系统地下水热量运移模拟参数敏感性分析

基于敏感性分析理论,以某地下水源热泵系统夏季运行为例,选取典型观测点温度值及回灌水热量影响范围作为模型输出结果,从局部和全局定性、定量地讨论了热泵系统特定水流和热源条件下地下水热量运移模拟中参数的敏感性问题。结果表明:模型输出结果对所选参数的局部敏感性程度和趋势差别明显;全局敏感性分析中其他参数不同取值对待分析参数敏感性各参数间共同作用对模型均存在影响,各参数组合全局敏感性趋势变化基本一致,模型稳定性较好。     

ANALYTICAL SOLUTION OF GROUNDWATER FLUCTUATIONS IN ESTUARINE AQUIFER

1.INTRODUCTIONTide-induced head fluctuations are a naturalphenomenon in a coastal aquifer[1-3].For an un-confined aquifer,groundwater level changes corre-sponding to the tidal waves.As the tidal propagateinland,their amplitude is attenuated and phase-shifts occur.A typical damping distance for tidalwater table fluctuation in an unconfined aquifer isseveral hundred meters whereas the tidal influenceon a confined aquifer can extended landward byseveral thousand meters[2,4].According to thef…     

浅层地热能不同开发方案对深层地下淡水咸化效应研究

为了保证浅层地热能可持续开发,同时控制深层承压淡水咸化,需评价浅层地热能开发对深层地下水咸化控制效应。基于地下水渗流、热量运移和溶质运移理论,以江苏省地质工程勘察院(南通分院)地下水源热泵系统为研究对象,建立松散孔隙地下水系统渗流—热量运移—溶质运移多场耦合数值模型,模拟预测了第Ⅰ承压含水层浅层地热能开发过程中地下水系统水位、温度、水化学浓度的演化规律,通过增大利用温差和减小夏季灌采比优化浅层地热能开发利用方案,定量评价增大利用温差和减小夏季灌采比对热贯通和深层地下淡水咸化的控制效应。结果表明：增大利用温差和减小夏季灌采比能有效缓解热贯通和深层淡水咸化的发展趋势,增大利用温差对深层地下淡水咸化的控制效应更为显著,减小夏季灌采比对热贯通的控制效应更为显著。     

Groundwater Level Forecasting in a Shallow Aquifer Using Artificial Neural Network Approach

Forecasting the ground water level fluctuations is an important requirement for planning conjunctive use in any basin. This paper reports a research study that investigates the potential of artificial neural network technique in forecasting the groundwater level fluctuations in an unconfined coastal aquifer in India. The most appropriate set of input variables to the model are selected through a combination of domain knowledge and statistical analysis of the available data series. Several ANN models are developed that forecasts the water level of two observation wells. The results suggest that the model predictions are reasonably accurate as evaluated by various statistical indices. An input sensitivity analysis suggested that exclusion of antecedent values of the water level time series may not help the model to capture the recharge time for the aquifer and may result in poorer performance of the models. In general, the results suggest that the ANN models are able to forecast the water levels up to 4 months in advance reasonably well. Such forecasts may be useful in conjunctive use planning of groundwater and surface water in the coastal areas that help maintain the natural water table gradient to protect seawater intrusion or water logging condition.     

Hydraulic Parameters of Coastal Aquifer Systems by Direct Methods and an Extended Tide–Aquifer Interaction Technique

Adequate and reliable parameters are key to the sustainable management of vital groundwater resources. Present study focuses on the evaluation of direct methods (tidal efficiency and time lag methods) and an extended tide–aquifer interaction technique for determining the hydraulic parameter of coastal unconfined and confined aquifer systems. The hydraulic diffusivities of unconfined and confined aquifer systems were estimated using the tidal efficiency and time lag methods as well as they were optimized using the tide–aquifer interaction model and the Levenberg–Marquardt optimization technique. The hydraulic diffusivities were optimized by the Levenberg–Marquardt technique following two approaches: lumped tidal component approach and multi-tidal component approach. The effect of spring and neap tidal data on parameter estimates was also analyzed. The tide–aquifer interaction data for two unconfined sites and three confined sites were used in this study. For all the five sites under study, the aquifer hydraulic diffusivities based on the time lag method were found to be much larger (2 to 14 fold for the unconfined sites and 5 to 8 fold for the confined sites) than those based on the tidal efficiency method. The analysis of the optimization results indicated that the hydraulic diffusivities following “multi-tidal component approach” are more reliable and accurate for both unconfined and confined aquifers than those obtained following “lumped tidal component approach”. Consequently, the use of “multi-tidal component approach” is strongly recommended for the determination of aquifer parameters by the tide–aquifer interaction technique. Furthermore, the tide–interaction data corresponding to spring and neap tidal events were found to significantly affect the aquifer diffusivities yielded by the tide–aquifer interaction technique. It is concluded that a judicious use of tide–aquifer interaction technique is indispensable for the reliable estimates of hydraulic parameters of coastal aquifer systems.     

Artificial Neural Network and Grey Wolf Optimizer Based Surrogate Simulation-Optimization Model for Groundwater Remediation

We herein propose a simulation-optimization model for groundwater remediation, using PAT (pump and treat), by coupling artificial neural network (ANN) with the grey wolf optimizer (GWO). The input and output datasets to train and validate the ANN model are generated by repetitively simulating the groundwater flow and solute transport processes using the analytic element method (AEM) and random walk particle tracking (RWPT). The input dataset is the different realization of the pumping strategy and output dataset are hydraulic head and contaminant concentration at predefined locations. The ANN model is used to approximate the flow and transport processes of two unconfined aquifer case studies. The performance evaluation of the ANN model showed that the value of mean squared error (MSE) is close to zero and the value of the correlation coefficient (R) is close to 0.99. These results certainly depict high accuracy of the ANN model in approximating the AEM-RWPT model. Further, the ANN model is coupled with the GWO and it is used for remediation design using PAT. A comparison of the results of the ANN-GWO model with solutions of ANN-PSO (ANN-Particle Swarm Optimization) and ANN-DE (ANN-Differential Evolution) models illustrates the better stability and convergence behaviour of the proposed methodology for groundwater remediation.

     

Groundwater Response to Tidal Fluctuation in an Inhomogeneous Coastal Aquifer-Aquitard System

This paper investigates tide-induced groundwater fluctuation and submarine groundwater discharge (SGD) in a leaky inhomogeneous coastal aquifer system with an upper unconfined aquifer, a lower confined aquifer, and an aquitard between them. The upper left aquifer is formed due to land reclamation. The SGD defined as the groundwater flow from land into the sea is controlled mainly by the hydraulic gradient between land and sea. An analytical expression is developed to discuss and assess the effect of inhomogeneity on the groundwater head fluctuation in the leaky aquifer system. Joint effects of aquifers’ parameters such as leakage and hydraulic diffusivity on the groundwater head fluctuation and SGD are investigated. The predicted results from the analytical expression indicate that the groundwater head fluctuation in both unconfined and confined aquifers is dependent on dimensionless leakages and increases with dimensionless hydraulic diffusivity.     

A Generalized Predictive Model of Water Table Fluctuations in Anisotropic Aquifer Due to Intermittently Applied Time-Varying Recharge from Multiple Basins

Mathematical models play a key role in assessing the future behavior of a groundwater system in response to various schemes of ground water resources development such as artificial recharging and in selecting an appropriate one out of many proposed schemes for its sustainable development. This paper presents an analytical solution of groundwater flow equation for unconfined, anisotropic, 2-D rectangular aquifer under the Boussinesq approximation to predict water table fluctuations in the aquifer in response to general time-varying intermittent recharge from multiple rectangular infiltration basins of different spatial dimensions. The horizontal anisotropy incorporated in the model is such that the principal axes of the hydraulic conductivity tensor are oriented parallel to the rectangular sides of the aquifer. The time-varying recharge rate is approximated by a series of line elements of different lengths and slopes depending on the nature of variation of recharge rate. The solution is obtained by using extended finite Fourier sine transform. Application of the solution is demonstrated with the help of synthetic examples. Numerical results of the analytical solutions are verified by comparison with the results obtained from MODFLOW. Numerical results indicate significant effect of anisotropy in hydraulic conductivity on the nature of water table variation.     

防渗墙作用下堤防保护区地下水动态数值模拟分析Ⅱ：二元结构堤基条件下的数值模拟

 对长江重要堤防典型二元结构堤基的地下水流运动进行了数值模拟。二维模拟结果表明：被河泓切割的承压含水层动态与江水位关系密切；表层弱透水层主要通过与承压含水层之间的补给排泄而受江水位的间接影响；全封闭防渗墙会制约堤防保护区承压含水层对江水位变化的响应；承压含水层透水性越强，这种制约作用越显著；全封闭防渗墙会使堤防保护区潜水含水层动态基本上不受江水位变化的影响。三维模拟结果表明：全封闭防渗墙端部自由绕渗会使端点附近承压含水层动态受防渗墙的影响减小；承压含水层的透水性越强，绕渗影响的程度和范围越大；绕渗在潜水含水层的作用则小得多，甚至可不予考虑。     

Evaluation of Analytical Methods to Study Aquifer Properties with Pumping Tests in Coastal Aquifers with Numerical Modelling (Motril-Salobreña Aquifer)

Two pumping tests were performed in the unconfined Motril-Salobreña detrital aquifer in a 250 m-deep well 300 m from the coastline containing both freshwater and saltwater. It is an artesian well as it is in the discharge zone of this coastal aquifer. The two observation wells where the drawdowns are measured record the influence of tidal fluctuations, and the well lithological columns reveal high vertical heterogeneity in the aquifer. The Theis and Cooper-Jacob approaches give average transmissivity (T) and storage coefficient (S) values of 1460 m²/d and 0.027, respectively. Other analytical solutions, modified to be more accurate in the boundary conditions found in coastal aquifers, provide similar T values to those found with the Theis and Cooper-Jacob methods, but give very different S values or could not estimate them. Numerical modelling in a synthetic model was applied to analyse the sensitivity of the Theis and Cooper-Jacob approaches to the usual boundary conditions in coastal aquifers. The T and S values calculated from the numerical modelling drawdowns indicate that the regional flow, variable pumping flows, and tidal effect produce an error of under 10 % compared to results obtained with classic methods. Fluids of different density (freshwater and saltwater) cause an error of 20 % in estimating T and of over 100 % in calculating S. The factor most affecting T and S results in the pumping test interpretation is vertical heterogeneity in sediments, which can produce errors of over 100 % in both parameters.