Prototype development to conduct oscillatory heat injection tests and evaluate the subsurface heat capacity when designing geothermal heat pump systems - I2I Phase 1

随着绿色建筑的建设，新兴的地热产业呈现出快速增长的趋势。设计用于商业、机构和工业建筑供暖和制冷的地热热泵系统需要对地下热性能进行现场评估。传统的测试方法，即热响应测试，只能用于测量地下导热系数。地下热容根据现有文献进行评估，并与钻探时确定的地质材料相关联，而无需进行任何现场实验或直接现场测量。这可能导致在设计地热系统和计算地面热交换器长度时的不确定性，这是地面耦合热泵中最昂贵的部件。该项目旨在开发一个原型并验证一种新的测试方法来评估地下热容量。原型机将用于商业前测试，基于振荡热注入和最近开发的带加热电缆的热响应测试。研究结果有望减少地面热特性的不确定性，从而更好地约束地热系统的设计并降低其安装成本。************

The emerging geothermal industry has shown rapid growth related to the construction of green buildings. Designing geothermal heat pump systems used for heating and cooling of commercial, institutional and industrial buildings requires an in situ assessment of the subsurface thermal properties. The conventional testing method, namely thermal response test, can only be used to measure the subsurface thermal conductivity. The subsurface heat capacity is evaluated from the available literature and associated to the geological materials identified while drilling without conducting any field experiments or direct in situ measurements. This can result in uncertainty when designing a geothermal system and calculating the length of the ground heat exchangers, which is the most expensive component of a ground-coupled heat pump. This project aims at developing a prototype and verifying a new test method to evaluate the subsurface heat capacity. The prototype will be built for pre-commercial tests, based on oscillating heat injection and recent development of thermal response tests with a heating cable. Results are expected to reduce uncertainty about the ground thermal properties to better constrain the design of geothermal systems and decrease their installation cost. ************