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.

该项目将基于现有的蒸汽升压器/水涡/车轮技术的应用，使用蒸汽喷射器/水轮机（Watergen）开发一种创新的，通用的微型CHP，该项目可以通过更有效地利用天然气和可再生能源来带来额外的发电和碳减少解决方案。为了安全性，稳定性和成本，水是理想的工作流体。这项新技术将解决英国基本供应问题的问题。该项目将包括计算机程序模型Watergen的理论性能。根据进行的模拟，对于1/2至1/9的夹带比（W Steam / W Water），效率（WNET / QBOILER）的范围在21％至34％的范围内。对于相同的工作条件，发现兽人效率为〜7％。进行了其他模拟，以确定进入注射器的蒸汽（运动流体）压力增加的循环效率。在此分析中，夹带比保持康斯坦塔斯1/5。发现在1-5 bar范围内增加的蒸汽压力略微降低了31％降低到30％，而对于相同条件，兽人效率在6.5-7.5％之间变化。总体而言，注射器 /水循环具有将低温热（100-150c浪费热 /太阳能）变成有用的功率的有希望的潜力。对于相同的工作条件，与当前使用的兽人循环相比，喷射器/水周期可提供更高的效率4-5倍。此外，将根据蒸汽喷射器在UON上建造和操作“概念验证”钻机，该蒸汽喷射器由Venturi Jet Pumps Ltd（VJP）设计和提供，并与Ashwell Biomass Ltd（ABM）指定并提供了商业上可用的PowerSpout PowerSpout Micro-Hydroectric Pelton Wheel/Generator。该钻机将在1至1.5 kW范围内具有标称电输出。涡轮水流为〜5至25 l/s，头为20至100 m。在30至70c的温度下，热输出在温度下为〜10至15 kW。该量表足够小用于实验室操作，但足够大以获得有意义的结果并证明概念。后者将被馈入模型，以评估较大装置的性能。该财团确信可以通过添加更多单元，通常在HE计划中进行，或者通过用于工业应用中的较大的涡轮/发电机/车轮套件来扩展水，这是较低成本和易于制造的车轮的蒸汽/水排出者，预计将在将蒸汽能量转换为电源方面具有良好的效率。蒸汽喷射泵具有低效率的断言，似乎与电动泵有所帮助。但是，这忽略了发电驱动泵的损失，因此不是有效的比较。预期总体水效率将足够高的原因，包括以下内容：1）水的蒸气压力及其良好的热稳定性意味着它可以在输入温度较高的情况下运行，而不是有机液，从而提高了Carnot效率。 2）最近的论文表明实验蒸汽/排出器的效率可以达到理论最大值的0.85。 3）Burns的工作表明，注入蒸汽喷射器泵的空气可提高效率。 4）尽管效率越高，实际单位中真正重要的是根据其资本和运营成本传递的电力的成本/千瓦时……与ORC Steam扩展器相比，WaterGen预计将是低成本设计，并且效率更高。基于锅炉的能量输入，功率输出的最小目标为10％。在开发的系统效率中，可以达到15-20％的效率。