EPSRC-FAPESP Efficient ground energy systems for deployment in diaphragm walls under challenging application scenarios

该项目是根据EPSRC与巴西FAPESP的牵头机构协议计划开发的，该协议允许联合国际工作。因此，该项目将由英国和巴西的一个综合团队交付；工作领域包括岩土工程、热分析和建筑服务工程，将岩土工程和机械工程师团队聚集在一起。该项目解决建筑物的供暖和制冷问题，这是实现NetZero目标的关键优先事项。全球近一半的能源使用与供暖有关(占英国排放量的四分之一)。在英国，制冷是一种次要的、但不断增长的排放源，但自1990年以来，全球用于制冷的能源消耗增加了两倍多，并将随着气候变化而继续增加。在巴西，公共和私人建筑的制冷占全国电力需求的一半(预计到2035年将增长40%)。迫切需要开发能够满足这些制冷和供暖需求的热能解决方案。在英国，热泵的部署进展没有要求的那么快，而在巴西，缺乏展示当地可行性的示范项目。热泵既适用于供暖，也适用于制冷，其中地源热泵(GSHP)提供了高效率。然而，降低资本成本需要进行创新。在地源热泵系统的子结构中引入换热管，即所谓的能源土工结构，是降低地源热泵系统成本的方法之一。该项目旨在解决嵌入式挡土墙在热能应用中的开发问题。嵌入的挡土墙，例如为支撑地下停车场而建造的，本身就是昂贵的结构，可能具有非常长的使用寿命。目前，它们的用途仅限于保留地面，但通过将它们纳入地源热泵系统，它们可以被建造成具有双重用途。这似乎是一件显而易见的事情，但它增加了设计和施工的复杂性。优化的好处和潜力，特别是在困难的地面条件下，还没有得到证实。因此，需要进行研究来说服行业和开发人员采用这些系统。该项目将为他们提供适当的设计工具和知识，将高效和优化的能源挡土墙整合到地源热泵系统中。我们将在巴西圣保罗大学(USP)建造一个受控实地考察场地，其中将包括一个具有不同管道几何形状的仪表式挡土墙系统，以便研究各种不同的墙运行模式。这将创建一个重要的数据集，专门针对南美洲当地的气候和地面条件。该系统的初步设计将得到数值模拟(利兹大学)的协助，数值模拟也将作为判断后续模拟和分析模型发展的基准。USP试验场和墙壁布置的比例物理模型将在邓迪大学制造，并在土工离心机上进行测试。这些物理模型将根据收集的现场数据进行验证。离心机测试将用于改变现场不易控制的不同参数，并测试更深的墙和地面条件，类似于英国的棕地开发。然后，利兹大学将利用现场和物理模型研究的数据和见解来开发设计这些结构的热分析工具。这将导致能源墙的快速运行瞬变解决方案，这些解决方案可以在各种地面条件下工作，并与现有的建筑能源建模软件集成。这些工具的开发将可用于更有效的嵌入式挡土墙地源热泵系统的实际设计，并消除采用的障碍。

This project has been developed under the EPSRC lead agency agreement scheme with FAPESP, Brazil, that allows joint international working. The project is therefore to be delivered by an integrated team in the UK and Brazil ; working across the fields of geotechnical engineering, thermal analysis and building services engineering bringing together a team of Geotechnical and Mechanical Engineers.The project tackles heating and cooling of buildings, which is a key priority for meeting NetZero targets. Almost half of global energy use is related to heating (one quarter of UK emissions). Cooling is a minor, but growing emissions source in the UK, but globally energy consumption for cooling has more than tripled since 1990, and will continue to increase with climate change. In Brazil, cooling public and private buildings is responsible for half of national electricity demand (predicted 40% increase by 2035). Thermal energy solutions that can deliver against these cooling and heating demands urgently need to be developed. In the UK, heat pump deployment is not progressing as fast as is required, while in Brazil, there is an absence of demonstrator projects showing local feasibility. Heat pumps are suited to both heating and cooling, with ground source heat pumps (GSHPs) offering high efficiencies. However, innovation is required to reduce capital costs.Inclusion of heat transfer pipes within sub-structures, so called energy geostructures, is one way to reduce costs of GSHP systems. This project aims to tackle the problem of developing embedded retaining walls for application in thermal energy. Embedded retaining walls, e.g. constructed to support underground car-parks, are themselves costly structures that can have very long lifetimes. Currently their use is restricted to retaining the ground, but they could be built to have dual purpose by incorporating them in a GSHP system. This would seem like an obvious thing to do but it adds additional complexity in design and construction. The benefits and potential for optimisation, especially in difficult ground conditions, are unproven. Thus, research is required to convince industry and developers to adopt these systems. This project will equip them with the appropriate design tools and knowledge to incorporate highly efficient and optimised energy retaining walls into GSHP systems.We will construct a controlled field study site at the University of Sau Paulo (USP) in Brazil that will include an instrumented retaining wall system with different pipework geometries to allow a wide variety of wall operation modes to be studied. This will create an important data set specific to the local South American climate and ground conditions. Initial design of the system will be aided by numerical simulation (University of Leeds) which will also serve as a benchmark to judge subsequent simulation and analytical model development. Scaled physical models of the USP test site and wall arrangements will be fabricated at the University of Dundee and tested on a geotechnical centrifuge. These physical models will be validated against the field data collected. Centrifuge testing will be used to vary different parameters that cannot be easily controlled on site and test deeper walls and ground conditions similar to brownfield land development in the UK. The University of Leeds will then use the data and insights from the field and physical model studies to develop thermal analytical tools for design of these structures. This will result in fast run transient solutions for energy walls that can work in a variety of ground conditions and be integrated with existing building energy modelling software. Development of these tools will then be available for practical design of more efficient embedded retaining wall GSHP systems and remove barriers to adoption.