回收率是衡量地热资源可开采量的指标。现行规范对回收率仅给出常数参考值,并未给出确定回收率的方法。对于开采深层地下热水这种普遍的地热利用方式,在确定回收率时应考虑其水资源属性。从深层地热开发技术的特点出发,提出确定回收率的约束条件为开采井水位、水温控制指标和地质环境保护。根据地下水动力学和热交换原理,提出了最大可能回收率的概念,给出了基于水位控制指标和基于联合控制指标的回收率确定方法。算例分析表明,回灌率是影响回收率的重要因素。
Recovery rate is the index to evaluate the workable reserves of geothermal resource. However, the current standard is only able to put forward a constant reference value for recovery rate without presenting the method for the determination. While the water resource property of hot groundwater should be considered during ensuring recovery rate for exploiting hot groundwater at deep level, a popular way for Utilizing geothermy. Considering the features of exploiting technique of deep geothermal resource, water table of the pumping well, temperature control of groundwater and protecting geologic environment are taken as the constraint conditions of determining recovery rate. Based on groundwater dynamics and heat exchange principle, the paper presents the concept of maximum recovery rate and brings forward the methods of determining recovery rate grounded on water table index and the combination control index. The example calculated in this article indicates that recharge rate is an important factor affecting the recovery rate.