GasNetNew - The role of the gas network in a future decarbonised UK

GasNetNew - 天然气网络在未来脱碳英国中的作用

• 批准号: EP/W008726/1
• 负责人: Seamus Garvey
• 金额: $ 164万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW008726%2F1
• 关键词: GasNetNew; role; gas; network; future

Heating indoor spaces by burning natural gas accounts for ~30% of the UK's total CO2 emissions. Around 23 million properties are connected to the gas network. Each 1kg of gas burned delivers ~12kWh of heat and releases ~4kg of CO2. That cannot continue in a future net-zero UK and capturing CO2 at individual buildings is completely implausible using any known technology.Many consider that hydrogen should replace natural gas in the gas network. Technically, this is feasible. Hydrogen can be produced from electrolysis or from natural gas. In case of the latter, 'carbon-capture' methods can collect most of the resulting CO2 and pump that underground. However, distributing hydrogen through the gas network might not necessarily be the most sensible course of action in all cases. This project will answer the question about how best to use different parts of existing gas network in a future net-zero UK. Even with carbon-capture, producing hydrogen from natural gas does cause some CO2 emissions. Typically >5% escapes. Using renewable electricity to make 'green' hydrogen via electrolysis and then burning that in boilers delivers less than 7kWh of heat into homes for every 10kWh of electricity used. By contrast, using electrically driven heat pumps can deliver 40kWh of heat for every 10kWh of electricity consumed. Although there are other advantages to producing hydrogen for heating, it remains questionable whether this is optimal in many parts of the UK.It is very likely that a large fraction of the existing infrastructure will be used for distributing hydrogen across the country. However, some specific parts of the network could be better exploited in a different way. This project will explore the different possible uses for those parts of the gas network. All of these potential uses are motivated mainly by solving problems that would arise if heat pumping were deployed very extensively in the UK as the primary heating mechanism. One possible future use for parts of the gas network is to feed non-potable water into properties. This water could serve as the source of low-temperature heat to support heat pumps. A new variety of heat pump turns incoming water into an ice slurry and discards the slurry to melt again later. This 'Latent Heat Pump' (LHP) can extract a lot of heat out of cold water (12L of water provides ~1kWh of heat). That heat emerges from the water at about 0C and as a consequence, the LHP can have a coefficient-of-performance (COP) >4 even when the outside air is very cold. For most air-source heat pumps, the COP falls sharply in very cold weather and, for obvious reasons, the COP matters most in very cold weather.A second possible future use for the gas network is to serve as a return (collection) network rather than as a delivery (distribution) network. Here, the fluid returning through the gas network would be an aqueous solution of a chemical that was hydrated (mixed with water) at the property to release heat. This measure would be taken only in very cold weather. Calcium Chloride and Magnesium Sulphate are two very cheap salts that release heat when dissolved in water. There are other inexpensive substances that release large quantities of heat upon reacting with water.Finally, if water was being conveyed in the low-pressure tiers of the gas network, the high-pressure tiers of the gas network would be free for another use. A very attractive possibility here would be to use those parts as the pressure vessel for a compressed air energy storage system. That system would simultaneously be able to assist the electricity transmission system by doing a parallel transmission from North to South at times of high North-South power traffic. How acceptable each of these propositions is to key social stakeholders (including policy makers, prospective business, and public end-users) will be integral to their real-world viability, and so will be examined here also.

燃烧天然气供暖的室内空间占英国二氧化碳排放总量的30%左右。大约有2300万处房产连接到了天然气网络。每燃烧1公斤的气体会产生约12千瓦时的热量，并释放约4公斤的二氧化碳。在未来的净零英国，这种情况不可能持续下去，使用任何已知的技术在个别建筑物捕获二氧化碳是完全不可能的。许多人认为氢气应该取代天然气网络中的天然气。从技术上讲，这是可行的。氢气可由电解法或天然气制得。在后一种情况下，“碳捕获”方法可以收集大部分产生的二氧化碳，并将其输送到地下。然而，通过天然气网络分配氢气并不一定在所有情况下都是最明智的做法。这个项目将回答如何在未来的零净额英国最好地利用现有天然气网络的不同部分的问题。即使有碳捕获，从天然气中生产氢气也会产生一些二氧化碳排放。通常情况下，&gt；5%的股票会逃脱。利用可再生电力通过电解生产“绿色”氢气，然后在锅炉中燃烧，每使用10kWh的电力，向家庭提供的热量不到7kWh。相比之下，使用电动热泵每消耗10千瓦时就可以提供40千瓦时的热量。尽管生产取暖用的氢气还有其他优势，但在英国的许多地区，这是否是最优的仍然值得怀疑。现有基础设施的很大一部分很可能将用于在全国范围内分配氢气。然而，网络的某些特定部分可以通过不同的方式得到更好的利用。该项目将探索天然气管网这些部分的不同可能用途。所有这些潜在的用途主要是为了解决在英国广泛使用热泵作为主要供暖机制时会出现的问题。天然气管网部分未来可能的一个用途是向物业提供非饮用水。这些水可以作为支持热泵的低温热源。一种新的热泵将进入的水转化为冰浆，然后丢弃这些浆液，稍后再次融化。这种“潜热泵”(LHP)可以从冷水中提取大量热量(12升水提供约1千瓦时的热量)。这些热量从水中散发出来，温度约为0摄氏度，因此，即使在外部空气非常冷的情况下，LHP也可以有一个性能系数(COP；4)。对于大多数空气源热泵来说，COP在非常冷的天气下会急剧下降，而且由于显而易见的原因，COP在非常冷的天气中最重要。燃气网络未来的第二个可能用途是作为回流(收集)网络，而不是作为输送(分配)网络。在这里，通过燃气网络返回的流体将是一种化学物质的水溶液，该化学物质在物业中水合(与水混合)以释放热量。只有在非常寒冷的天气里才会采取这一措施。氯化钙和硫酸镁是两种非常便宜的盐，溶解在水中会放出热量。还有其他便宜的物质，与水反应时会释放大量热量。最后，如果水在燃气网络的低压层中输送，高压层将被释放出来供其他用途。这里一个非常有吸引力的可能性是将这些部件用作压缩空气能量存储系统的压力容器。该系统将同时能够在南北电力交通量高的时候进行从北到南的平行输电，从而帮助电力传输系统。关键的社会利益相关者(包括政策制定者、潜在企业和公共最终用户)对这些主张的接受程度将是它们在现实世界中生存不可或缺的一部分，因此也将在这里进行考察。

项目成果

The effect of a nuclear baseload in a zero-carbon electricity system: An analysis for the UK

零碳电力系统中核基本负荷的影响：对英国的分析

• DOI: 10.1016/j.renene.2023.01.028
• 发表时间: 2023
• 期刊: Renewable Energy
• 影响因子: 8.7
• 作者: Cárdenas B

Correction: Evans et al. Salt Cavern Exergy Storage Capacity Potential of UK Massively Bedded Halites, Using Compressed Air Energy Storage (CAES). Appl. Sci. 2021, 11, 4728

更正：埃文斯等人。

• DOI: 10.3390/app12073327
• 发表时间: 2022
• 期刊: Applied Sciences
• 作者: Evans D