H2-Heat: Thermal energy transport for heating and cooling with innovative hydrogen(H2) technologies

在英国，热量占全国温室气体排放量的三分之一以上。我们工业和建筑中的大部分供暖和制冷都是由化石燃料直接或间接提供的。除了温室气体排放，化石燃料的大量消耗还会导致能源的大量枯竭、余热的产生和对周围环境的污染。为了实现到2050年温室气体净零排放的目标，迫切需要通过利用先进技术利用可再生能源和工业废热来实现供暖和制冷的脱碳。与太阳能等可再生能源相比，工业废热资源具有更大的稳定性、更低的成本和更大的温度范围等明显优势。因此，工业废热回收用于脱碳供暖和制冷是一个有吸引力的概念，可以同时减少化石燃料消耗和二氧化碳排放。显然，在英国，根据最近的一份报告，已确定约有48太瓦时/年的工业废热来源可用，其中约28太瓦时/年可潜在地用于满足供暖和制冷需求。包括钢铁、炼油厂、陶瓷、玻璃、水泥、化工、食品和饮料、造纸和纸浆在内的所有热密集型工业部门都可以为这一潜力做出贡献。即便如此，也需要设计和应用高效的能量转换系统，以最大限度地利用余热来供暖和制冷。另一方面，钢铁厂等工业废热供应商的位置大多远离供暖和制冷的公用事业单位。传统上，利用工业废热加热的热水通过长距离水管输送到最终用户现场，由于水流摩擦压降大，水流与周围环境温差大，会造成巨大的水泵功率消耗和热损失。因此，用于脱碳加热和冷却的长距离余热传输和高效创新的能源转换技术面临着挑战。为了应对这些挑战，在本提案中，将开发一种新的脱碳区域供暖和制冷系统(H2-HEAT)的战略，将现场金属氢化物(MH)热泵、长距离氢气和热传输以及MH供暖和冷却系统集成在一起，为最终用户提供服务。在该系统中，塔塔钢铁厂或类似工业现场的低品位热(~210C)和超低品位热(~40C)将作为热源，而建筑供热和制冷空间则分别作为最终用户端的散热器和低温热源。将确定和研究MH热泵、具有MH的热驱动化学压缩机、长距离氢气和热传输、MH空间加热和冷却、MH合金和反应堆在系统和工艺中的应用、空间加热和冷却的控制等技术。最终，利用塔塔钢铁厂或其他工业现场的工业余热，在实验室建设一个具有5kW供热或制冷能力、高热效率的脱碳区域供热和供冷试验系统。此外，将为所建立的系统开发和验证详细的数学模型；这可以用于塔塔钢铁厂或其他有低品位余热的工业现场的系统扩大到实际应用。到目前为止，还没有在国内或国际上找到关于这种系统的研究活动。重要原因包括难以选择用于空间供暖和制冷的热驱动长距离氢和热传输系统及相关的MH合金，以及H2热系统中MH反应堆的复杂设计。这些挑战和问题将通过这一拟议项目加以处理和解决。

In the UK, heat accounts for over a third of the nation's greenhouse gas emissions. Most of the heating and cooling in our industries and buildings are delivered directly or indirectly by fossil fuels. Apart from the greenhouse emissions, the extensive consumption of fossil fuels can also lead to a large depletion of energy resources, waste heat production and pollution to the surrounding environment. To meet the target of Net Zero greenhouse gas emissions by 2050, there is an urgent need for decarbonising heating and cooling by utilising renewable energy and industrial waste heat with advanced technologies. Compared to renewable energy such as solar, the resources from industrial waste heat have clear advantages including greater stabilisation, less cost and larger temperature ranges. Therefore, industrial waste heat recovery for decarbonised heating and cooling is an attractive concept that could simultaneously reduce fossil fuel consumption and CO2 emissions. Evidently, in the UK, based on a recent report, it was identified that around 48 TWh/yr industrial waste heat sources were available of which about 28 TWh/yr could be potentially used to meet the heating and cooling demands. All heat-intensive industrial sectors including iron & steel, refineries, ceramics, glass, cement, chemicals, food and drink, paper and pulp can contribute to this potential. Even so, high efficient energy conversion systems need to be designed and applied so as to maximize the waste heat utilisations for heating and cooling. On the other hand, the locations of industrial waste heat providers such as steel plants are mostly far away from the utilisers for heating and cooling. Conventionally, hot water heated by the industrial waste heat is transported through long distance water pipe to the end user site which can cause huge pump power consumption and heat losses due to significant friction pressure drop for the water flow and large temperature difference between water flow and ambient. There are therefore challenges to the long-distance waste heat transport and high-efficient and innovative energy conversion technologies for the decarbonising heating and cooling. To address these challenges, in this proposal, strategies for a novel concept of decarbonising district heating and cooling system (H2-heat) will be developed with the integration of metal hydride (MH) heat pump on site, long distance hydrogen and heat transport, and MH heating and cooling for end users. In such a system, low grade heat (~210C) and extra low grade heat (~40C) from TATA Steel plant or a similar industry site will be used as heat sources while building heating and cooling spaces are applied as heat sink and low temperature heat source respectively at end user side. Technologies of MH heat pump, a thermal driven chemical compressor with MH, long distance hydrogen and heat transport, MH space heating and cooling, MH alloys and reactors applied in the systems and processes, controls for space heating and cooling etc. will be identified and investigated. Ultimately, a decarbonising district heating and cooling test system with industrial waste heat from TATA Steel plant or other industrial sites will be constructed in lab with 5 kWth heating or cooling capacity and high heat transport efficiency. Furthermore, a detailed mathematical model will be developed and validated for the established system; this can be used for a system scale-up into actual application in TATA Steel plant or other industrial sites where low grade waste heat is available. As yet, no research activity on such a system can be found either nationally or internationally. Important reasons include the difficulty in choosing a thermal driven long distance hydrogen and heat transport system and associated MH alloys for space heating and cooling and complicated designs of MH reactors in the H2-heat system. These challenges and issues will be addressed and solved by this proposed project.