Low Temperature Waste Heat to Power Generation

低温余热发电

基本信息

批准号：
EP/P510294/1
负责人：
Savvas Tassou
金额：
$ 41.12万
依托单位：
Brunel University London
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%2FP510294%2F1
关键词：
Low Temperature Waste Heat Power

项目摘要

Most of the waste heat (more than 60%) from industrial processes and institutional buildings, is low grade heat which makes its direct use within the facility difficult and also reduces the potential for power generation using Rankine or Organic Rankine Cycles (ORCs). ORCs also require that adequate pressure and consequently temperature differential is maintained between the heat source and heat sink to provide sufficient expansion energy for the turbine. This limits the temperature that the heat source can be cooled down to and the heat recovery and power generation potential. The Main aim of this project is to overcome the limitations of conventional technologies by developing an innovative low temperature heat to power conversion system that can recover energy from low temperature waste heat streams. The project addresses the energy trilemma through: i) Reduction of Emissions: by generating electricity from low temperature waste heat and displacing fossil fuel use. ii) Security of supply: the generation of electricity from a waste heat will reduce the amount of primary fuel required and provides an alternative source of energy supply. iii) Cost savings: using waste heat will result in significant cost savings for the users. The system will be optimised for maximum efficiency at heat source temperatures 75 C to 90 C to maximise the range of applications and potential markets. It will operate on what we term 'Controlled Phase Cycle (CPC)'. The CPC is a variant of the Trilateral Flash Cycle (TFC), which is a 3-leg power cycle in which the working fluid expands from saturated liquid state at high pressure to a two-phase state at lower pressure in an expander before rejecting heat and condensing in the condenser. The resulting liquid is then compressed by a feed pump to the higher pressure level before is heated up by the heat source (waste heat stream) and re-expanded. The 'wet' expansion increases significantly the power output compared to the ORC. The TFC has not been commercialised as yet, due to the low efficiency of available expanders and high parasitic losses, particularly pumping power. These shortcomings will be overcome by innovations in this project which include: i) Control of the quality of the fluid before expansion to a high wetness fraction to increase expansion efficiency;ii) Thermal instead of mechanical pumping of the liquid from the condenser to the expansion pressure; iii) Innovative heat exchanger design and controls to maximise heat transfer from the waste heat stream and minimise pressure losses;iv) Improved screw expander rotor profile to further increase efficiency. The project will lead to a proof of concept system to be installed for demonstration and evaluation in a dairy facility.

来自工业流程和机构建筑的大部分废热（超过 60%）都是低品位热能，这使得其在设施内直接利用变得困难，并且还降低了使用朗肯或有机朗肯循环 (ORC) 发电的潜力。 ORC 还要求在热源和散热器之间保持足够的压力和温差，以为涡轮机提供足够的膨胀能量。这限制了热源可以冷却到的温度以及热回收和发电潜力。该项目的主要目标是通过开发一种创新的低温热能转换系统来克服传统技术的局限性，该系统可以从低温废热流中回收能量。该项目通过以下方式解决能源难题：i) 减少排放：利用低温废热发电并取代化石燃料的使用。 ii) 供应安全：利用废热发电将减少所需初级燃料的数量，并提供替代能源供应。 iii) 节省成本：利用废热将为用户带来显着的成本节省。该系统将进行优化，以在热源温度 75°C 至 90°C 下实现最大效率，从而最大限度地扩大应用范围和潜在市场。它将按照我们所说的“受控相位循环（CPC）”运行。 CPC 是三边闪蒸循环 (TFC) 的一种变体，它是一种三腿动力循环，其中工作流体在排出热量之前在膨胀机中从高压饱和液态膨胀到低压两相状态并在冷凝器中冷凝。然后，所得液体被进料泵压缩至较高压力水平，然后被热源（废热流）加热并重新膨胀。与 ORC 相比，“湿”膨胀显着增加了功率输出。由于现有膨胀机效率低且寄生损耗（尤其是泵浦功率）高，TFC 尚未商业化。这些缺点将通过该项目的创新来克服，其中包括：i）在膨胀至高湿度分数之前控制流体质量，以提高膨胀效率；ii）将液体从冷凝器热泵送至膨胀器，而不是机械泵送压力; iii) 创新的热交换器设计和控制，以最大限度地提高废热流的传热并最大限度地减少压力损失；iv) 改进螺杆膨胀机转子轮廓，以进一步提高效率。该项目将导致安装一个概念验证系统，用于在乳品厂中进行演示和评估。