Micro-CHP using steam ejector/water turbine (WaterGen)

使用蒸汽喷射器/水轮机 (WaterGen) 的微型热电联产

• 批准号: EP/N509875/1
• 负责人: Saffa Riffat
• 金额: $ 18.96万
• 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: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FN509875%2F1
• 关键词: Micro; CHP; using; steam; ejector

This project will develop an innovative, generic micro-CHP using steam ejector/water turbine (WaterGen), based on an application of existing steam-ejector/water-turbine/wheel technology, which, can bring additional power generation andcarbon reduction solutions over the next decade by the more efficient utilisation of both natural gas and renewable energy. For safety, stability and cost, water is the ideal working fluid. The new technology will address the fundamental UK energysupply problems.The project will include a computer program model the theoretical performance of WaterGen. According to the simulations conducted, for entrainment ratios (W steam / W water) 1/2 to 1/9, efficiency (Wnet / Qboiler) is found in the range of 21% to34%. For the same operating conditions ORC efficiency is found as ~7%. Additional simulations carried out to determine the cycle efficiency for the increasing steam (motive fluid) pressure entering the injector. Entrainment ratio is kept constantas 1/5 in this analysis. It is found that increasing steam pressure in the range of 1 -5 bar slightly decreases the cycle efficiency from 31% to 30% whilst for the same conditions ORC efficiency varies between 6.5-7.5%. In overall it is found that injector/water cycle has a promising potential to turn low temperature heat (100-150C waste heat /solar energy) into useful power. For the same operating conditions injector/water cycles can provide 4-5 times higher efficiency in comparison with currently used ORC cycles. Moreover, a "proof of concept" rig will be constructed and operated at UoN based on a steam ejector, designed and supplied by Venturi Jet Pumps Ltd (VJP), mated with a commercially available PowerSpout micro-hydroelectric Pelton wheel/generator specified and supplied by Ashwell Biomass Ltd (ABM). The rig will have a nominal electrical output in the range 1 to 1.5 kW. Turbine water flows will be ~ 5 to 25 L/s with heads of 20 to 100 m. The thermal output will be ~ 10 to 15 kW at temperatures in the range 30 to 70C. This scale is small enough for lab operation,but large enough to obtain meaningful results and to prove the concept. The latter will be fed into the model to assess the performance of larger installations. The consortium is confident that WaterGen can be scaled up, both by adding more units, commonly done in HE schemes, or by using larger turbine/generator/wheel sets for industrial applications.The steam/water ejector with low cost and easy to manufacture wheel is expected to have good efficiency in converting steam energy into power. The assertion, sometimes made, that steam ejector pumps have low efficiency appears to be incomparison with electric pumps; but this ignores the losses in generating the electric power to drive the pump so is not a valid comparison. Reasons for anticipating that the overall WaterGen efficiency will be high enough including the following: 1) the lower vapour pressure of water and its good thermal stability means it can operate at higher input temperatures than organic fluids resulting in higher Carnot efficiency. 2) A recent paper indicates experimental steam/water ejector efficiencies can reach 0.85 of the theoretical maximum. 3) Work by Burns suggests that air injection into steam ejector pump improves efficiency. 4) Although the higher the efficiency the better what really matters in a practical unit is the cost/kWh of the power delivered based on its capital and operating costs...WaterGen is anticipated to be a low cost design and higher efficiency than ORC steam expander. The minimum target for the power output is 10% based on the energy input to the boiler. In a developed system efficiencies of 15-20% could be achievable.

该项目将基于现有蒸汽喷射器/水轮机/轮技术的应用，开发一种使用蒸汽喷射器/水轮机（WaterGen）的创新型通用微型热电联产系统，可以带来额外的发电和碳减排解决方案。下一个十年将更加有效地利用天然气和可再生能源。出于安全性、稳定性和成本考虑，水是理想的工作流体。这项新技术将解决英国的基本能源供应问题。该项目将包括一个计算 WaterGen 理论性能的计算机程序模型。根据进行的模拟，对于夹带比（W 蒸汽/W 水）1/2 至 1/9，效率（Wnet / Qboiler）在 21% 至 34% 的范围内。对于相同的操作条件，ORC 效率约为 7%。进行额外的模拟以确定进入喷射器的蒸汽（动力流体）压力增加的循环效率。在此分析中，夹带比保持恒定为 1/5。结果发现，在 1 -5 bar 范围内增加蒸汽压力会略微降低循环效率，从 31% 降至 30%，而对于相同条件，ORC 效率在 6.5-7.5% 之间变化。总体而言，我们发现喷射器/水循环具有将低温热量（100-150C 废热/太阳能）转化为有用电力的巨大潜力。在相同的操作条件下，喷射器/水循环的效率比目前使用的 ORC 循环高 4-5 倍。此外，UoN 将建造和运行一个“概念验证”钻机，该钻机基于由 Venturi Jet Pumps Ltd (VJP) 设计和提供的蒸汽喷射器，并与指定和提供的市售 PowerSpout 微型水力冲击轮/发电机配合使用由 Ashwell Biomass Ltd (ABM) 提供。该钻机的标称电力输出范围为 1 至 1.5 kW。涡轮水流量约为 5 至 25 L/s，水头为 20 至 100 m。在 30 至 70°C 的温度范围内，热输出约为 10 至 15 kW。这个规模对于实验室操作来说足够小，但又足够大以获得有意义的结果并证明这个概念。后者将被输入模型以评估大型装置的性能。该财团相信 WaterGen 可以扩大规模，既可以通过添加更多机组（通常在 HE 方案中完成），也可以通过在工业应用中使用更大的涡轮机/发电机/轮组。蒸汽/水喷射器成本低且易于制造轮预计在将蒸汽能转化为电力方面具有良好的效率。有时有人断言蒸汽喷射泵效率低，这似乎与电动泵无法相比；但这忽略了产生驱动泵的电力的损失，因此不是有效的比较。预计整体 WaterGen 效率将足够高的原因包括：1) 水的蒸气压较低且其良好的热稳定性意味着它可以在比有机流体更高的输入温度下运行，从而产生更高的卡诺效率。 2) 最近的一篇论文表明，实验蒸汽/水喷射器效率可以达到理论最大值的 0.85。 3) Burns 的研究表明，将空气注入蒸汽喷射泵可提高效率。 4) 虽然效率越高越好，但在实际装置中真正重要的是基于其资本和运营成本的每千瓦时发电成本……WaterGen 预计将是一种低成本设计，并且比 ORC 蒸汽效率更高扩展器。功率输出的最低目标是基于锅炉能量输入的 10%。在开发的系统中，可以实现 15-20% 的效率。