The Use of Geothermal Energy for the Decarbonisation of Heat in Greater Manchester

利用地热能实现大曼彻斯特热量脱碳

• 批准号: NE/Y004973/1
• 负责人: David Johnstone
• 金额: $ 24.97万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FY004973%2F1
• 关键词: Use; Geothermal; Energy; Decarbonisation; Heat

The earth's climate is warming, and scientific evidence shows that this is due to greenhouse gases like carbon dioxide being emitted during the combustion of fossil fuels such as coal, oil, and natural gas. The more greenhouse gases that are added, the hotter the earth will become, and so reducing their emissions is something we should all care about. We can reduce emissions by using renewable sources of energy which do not involve the burning of fossil fuels. Generation of electricity using wind or solar has been successful in the UK, although the use of fossil fuels for heat is still widespread as most houses and offices have a gas or oil boiler to provide heating and hot water. One possible low-carbon alternative is to use heat from geothermal energy. This involves harnessing the natural heat present within the earth. The term geothermal energy refers to any heat derived from the ground, from depths of a few metres to multiple kilometres beneath the Earth's surface.The deeper you travel into the earth the hotter it becomes. In the first 10 meters, layers are warmed by the sun, below this the deeper layers of rock are heated by radiation from the earth's core. The rate of temperature increase with depth is known as the geothermal gradient. Below Manchester the geothermal gradient is around 28 degrees Celsius (degC) per kilometre. For example, if the surface temperature is 10degC then at 1km below Manchester the temperature of will be 38degC (10+28). To extract this heat, you need water. Heat from the surrounding rock is transferred into water stored within these rocks at depth. If the geology is right this can then be then pumped to surface and used to warm buildings, greenhouses, or swimming pools. If water can flow naturally from the rock, it is described as a permeable aquifer. This permeability may be due to interconnected space (known as porosity) between the grains in the rock, you can think of it as being like a bath sponge. Not all rocks have this space between the grains, they have low or no porosity. Water may still be able to flow through these rocks, however, if they are broken or fractured. Think of hitting a pane of glass placed on the ground. Water would still not flow through the individual pieces but could find its way through the cracks. In the same way, fractured rocks can still be a permeable aquifer. A special group of aquifers occurs in the coal mines below Manchester. These aquifers are not natural, but the permeability is created by the tunnels dug out, by thousands of men, women and children undergoing great hardship to mine coal. What a fantastic legacy if we could then use all their hard work to heat our homes, not with coal, but with warm water extracted from these underground voids.The main aim of this project is to make maps of these underground aquifers and mines so we can find the best places to drill and extract this geothermal energy. To do this we need to "look" into the earth using methods such as seismic reflection surveying. We send sound waves into the earth and measure the time taken for them to come back, a little like a bat does when hunting for food. This gives us a "picture" of different layers and their position in the earth. We then trace these in three dimensions to show how their depth varies under the whole of Manchester. If we know the depth, we can predict the temperature of the water using the geothermal gradient. In Greater Manchester many holes (called wells) have been drilled to explore for natural resources such as coal, water and natural gas. They give us a direct view of what types of rocks are below our feet, and whether they are able to produce heated water for geothermal energy. By mapping the depth and temperature of these aquifers we can design wells to extract the heat and move forwards in our decarbonisation of Greater Manchester.

地球气候正在变暖，科学证据表明，这是由于燃烧煤炭、石油和天然气等化石燃料时排放的二氧化碳等温室气体造成的。增加的温室气体越多，地球就会变得越热，因此减少温室气体的排放是我们都应该关心的事情。我们可以通过使用不涉及燃烧化石燃料的可再生能源来减少排放。风能或太阳能发电在英国已经取得了成功，尽管使用化石燃料取暖的情况仍然很普遍，因为大多数家庭和办公室都有燃气或燃油锅炉来提供暖气和热水。一种可能的低碳替代方案是使用地热能提供的热量。这涉及到利用地球内部存在的自然热量。地热能这个术语指的是任何来自地下的热量，从几米到地表下几公里的深度。你进入地下越深，它就变得越热。在前10米，岩层被太阳加热，在这10米以下，更深层的岩石受到地核辐射的加热。温度随深度增加的速率称为地温梯度。在曼彻斯特下方，地温梯度约为每公里28摄氏度。例如，如果表面温度是10摄氏度，那么在曼彻斯特以下1公里处的温度将是38摄氏度(10+28)。要吸收这些热量，你需要水。来自围岩的热量被转移到深层储存在这些岩石中的水中。如果地质是正确的，然后可以抽水到水面，用来为建筑物、温室或游泳池取暖。如果水可以从岩石中自然流出，它就被描述为可渗透的含水层。这种渗透性可能是由于岩石颗粒之间的相互联系的空间(称为孔隙率)，你可以把它想象成一块沐浴海绵。并不是所有的岩石在颗粒之间都有这种空间，它们的孔隙度很低或没有。然而，如果这些岩石破裂或破裂，水可能仍然能够流过这些岩石。想象一下，撞到一块放在地上的玻璃窗。水仍然不会流过单独的碎片，但可以通过裂缝找到自己的路。同样，裂隙岩石仍然可以是可渗透的含水层。一组特殊的含水层出现在曼彻斯特下方的煤矿中。这些含水层不是天然的，但渗透性是由成千上万的男人、女人和儿童在采煤时辛辛苦苦挖出的隧道造成的。如果我们能够利用他们所有的辛勤工作来为我们的家园供暖，而不是用煤，而是用从这些地下空间中提取的温水，那将是一项多么美妙的遗产。这个项目的主要目标是绘制这些地下含水层和矿山的地图，这样我们就可以找到钻探和提取地热能的最佳地点。要做到这一点，我们需要使用地震反射测量等方法来“观察”地球。我们向地球发送声波，并测量它们回来所需的时间，就像蝙蝠在捕食时所做的那样。这为我们提供了一幅不同地层及其在地球上的位置的“图片”。然后我们在三个维度上追踪它们，以显示它们在整个曼彻斯特的深度是如何变化的。如果我们知道深度，我们就可以利用地温梯度来预测水温。在大曼彻斯特地区，为了勘探煤炭、水和天然气等自然资源，人们钻了很多洞(称为井)。它们让我们直观地看到我们脚下有哪些类型的岩石，以及它们是否能够产生用于地热能的热水。通过绘制这些含水层的深度和温度图，我们可以设计井来提取热量，并在大曼彻斯特的脱碳过程中向前推进。