A novel 2kWe biomass-organic rankine cycle micro cogeneration system
A novel 2kWe biomass-organic rankine cycle micro cogeneration system
复制标题
一种新型2kWe生物质-有机朗肯循环微型热电联产系统
DOI：
--
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Ferdinand Daminabo
中科院分区：
文献类型：
--
作者：
Ferdinand Daminabo
能源可能是现代文明的中心，从工业革命开始，技术已经完善和重新定义了我们使用能源的方式;但所有领域的技术进步将继续依赖和使用能源来进步。然而，化石燃料（煤、天然气、石油）仍然是占主导地位的能源，与核能和可再生能源相比，在世界能源消费中所占比例更大。人们越来越担心，由于全球变暖，气候和我们的环境都将达到一个典型的临界点。这与化石燃料的无情使用和温室气体的不受控制的排放有关。这一持续趋势引发了对替代能源和可再生能源选择的需求，目前正在全球范围内审议和寻求这些选择，以避免气候变化达到不可逆转状态的可能性。本研究描述了一种新型2kWe生物质燃烧有机朗肯循环（ORC）系统的开发，该系统旨在用于远程离网位置，采用多叶片膨胀机作为原动机。
膨胀机是由Gast Manufacturing Inc.制造的四叶片型6AM-FRV-5A 3 kW Gast Air马达。原动机将利用高压蒸汽产生的动力在轴上产生扭矩和旋转运动，所产生的机械能通过汽车交流发电机转换为电能。本研究以低成本、轻量化、低维护的膨胀机以及有机物或氢氟醚、HFE 7100和HFE 7000为主要研究对象，将生物质中低温热能转化为电能。为了评估和预测系统的性能，进行了基本循环的EES模拟，以便将结果与实际循环进行比较。还对系统进行了初步的空气测试，以了解使用压缩空气的实际性能。
然而，选择在进一步测试中使用的有机物质氢氟醚（HFE）是因为其具有比蒸汽低的比容和高的分子量的热力学性质，从而允许更小、更不复杂、成本更低的能量应用，如用于低温微系统的膨胀器和更小直径的管。与在较高温度和压力下运行的涡轮机相比，这是通过朗肯循环过程中在指定温度极限之间的相变实现的。
实验研究和初步测试是使用Chromalox-CES-12型9千瓦锅炉进行的，温度在100摄氏度和115摄氏度之间，并对测试测量结果进行整理和分析，以预测性能和评估系统的输出和可能的波动。
随后进行了涉及使用生物质锅炉的试验，并与电锅炉进行了比较分析。该过程将涉及从生物质锅炉供应热量，并且在ORC循环中产生的高压蒸汽通过原动机膨胀，在排气处温度和压力下降，并作为饱和蒸汽或蒸汽和液体的混合物离开。储存在蒸汽状态的工作流体中的能量通过轴上的功转化为电能，而当蒸汽在冷凝器中膨胀到低压时，废热可以用于家用，饱和液体在蒸发器中被泵送到高压以恢复循环。
Energy is potentially at the hub of modern civilization and right from Industrial Revolution, technology has refined and redefined the way we use energy; but technological advancement in all spheres will continue to depend and use energy to progress. However, fossil fuels (coal, gas, oil) have remained the dominant energy resource accounting for a larger proportion of world energy consumption when compared to nuclear energy and renewable energy resources. There are mounting fears of both the climate and our environment reaching a characteristic tipping point due to global warming. This is associated with the relentless use of fossil fuels and uncontrolled emissions of greenhouse gases. The persistent trend has triggered the need for alternative and renewable energy options which are now being considered and pursued globally to avert the possibility of climate change attaining a state of irreversibility. This research describes the development of a novel 2kWe biomass fired Organic Rankine Cycle (ORC) system intended for remote off-grid locations, employing a multi-vane expander as the prime mover.
The expander is a four vane model 6AM-FRV-5A 3kW Gast Air motor manufactured by Gast Manufacturing Inc. The prime mover will harness power produced by high pressure vapour to generate torque and rotational motion on the shaft and the mechanical energy generated is converted to electricity by means of an automotive alternator. The conversion of low and medium temperature heat from biomass to electricity by using low cost, lightweight and low maintenance expander as well organic substances or hydrofluoroether, HFE 7100 and HFE 7000 is the subject ofthis research. In order to assess and predict the performance of the system an EES simulation of a basic cycle is carried out in order to compare the the outcome with the actual cycle. A preliminary air test of the system was also carried out to have a perspective on actual performance using compressed air.
However, the organic substance, hydrofluoroether (HFE) to be used in further tests is selected because of its thermodynamic properties of having a lower specific volume and higher molecular weight than steam allowing for smaller, less complex, less costly energy applications like expanders and smaller diameter tubes to be employed for low temperature micro system. This is achieved through a phase change transformation in a Rankine cycle process between specified temperature limits when compared to turbines which operate at higher temperature and pressure.
An experimental study and initial testing is carried out using a Chromalox- Model CES-12, 9 kW boiler providing temperatures between 100oC and 115oC and test measurements collated and analysed to predict performance and assess outputs and possibly fluctuations in the system.
A test involving the use of the biomass boiler is carried out later and analysed results compared with that of the electric boiler. The process will involve the supply of heat from the biomass boiler and the high pressured vapour generated in the ORC cycle is expanded through the prime mover with a fall in temperature and pressure at the exhaust and exiting as saturated vapour or a mixture of vapour and liquid. The energy stored in the working fluid in the vapour state is converted to electricity by work on the shaft while the exhaust heat can be tapped for domestic uses as thevapour is expanded down to low pressure in the condenser and the saturated liquid is pumped to a high pressure in the evaporator to resume the cycle.