Next-generation ammonia adsorption heat pump cycles and technology 1=Energy 2=Energy Efficiency

新一代氨吸附热泵循环和技术 1=能源 2=能源效率

基本信息

批准号：
2199243
负责人：
金额：
--
依托单位：
University of Warwick
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2019
资助国家：
英国
起止时间：
2019 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2199243
关键词：
Next generation ammonia adsorption heat

项目摘要

in reducing the CO2 emissions associated with domestic heating. One ammonia - water absorption technology is commercialised, with good GUE (Gas Utilisation Efficiency, heat out/gross calorific value of gas in of c. 1.4) but high capital cost. An ammonia - carbon adsorption cycle is under development, offering reduced GUE of 1.2 but affordable capital cost. Two possibilities exist to improve the adsorption cycle GUE without a major increase in capital cost. One is a development of the carbon ammonia technology employing either multiple adsorbers with improved heat recovery and the other using chemical adsorbents, generally halide salts embedded in a graphite matrix and used in resorption cycles. Both have been the subject of preliminary work at Warwick.The research programme will first undertake sufficient analysis and modelling to decide which of either the active carbon or metal halide adsorbent types has the greater potential for eventual commercial adoption. The carbon adsorbent can certainly achieve a GUE of 1.4 at the expense of some extra complexity. The metal salt route is lower Technology Readiness Level but in theory could offer a GUE of 1.5 in a two-salt cycle and 2.0 in a three-salt cycle.The challenges presented by the two technologies are somewhat different. The carbon adsorbent is well characterised and understood. The difficulties are in construction of a carbon ammonia adsorber with low thermal mass, good heat and mass transfer and low cost; this has already been the subject of many years' effort. A multiple bed with advanced heat recovery introduces further complexities in design and simulation. The adsorbers in a metal salt system are very different in that the salts are contained within a conductive (non-adsorbing) graphite matrix which improves conductivity. The resorption cycles also have the benefits of fewer components. However, the chemical reactions that take place are much more problematic with reaction rates very difficult to predict. Where the active carbon in the carbon-ammonia machines is always in chemical equilibrium and operation is heat transfer limited, within metal salt - ammonia systems there is never equilibrium and operational performance depends on the poorly understood reaction rate dynamics.Having made a choice between the two competing technologies (expected by Month 9) the research will enter a detailed design and simulation phase in which proposed adsorber designs are evaluated at 'unit-cell' level using the Large Temperature Jump (LTJ) technique already established at Warwick. With the validation of the adsorber design, construction of a proof of concept machine (3-10 kW output) will commence and simulation of control strategies begun. The POC machine will be tested first in the ThermExS laboratory, purpose-built under an EPSRC capital grant for the easy evaluation of novel thermodynamic systems. It consists of four computer-controlled thermal baths, valve and pump assemblies that act as heat sources and sinks from -10 to 180 C and powers from 7 to 30 kW.This level of testing, electrically heated and within the laboratory is sufficient to prove the chosen cycle/adsorbents and result in new knowledge worthy of a PhD. However, it is quite probable that by this time there will be newly funded projects at Warwick that will enable the work to go further, perhaps integrating with a gas burner in a stand-alone system.

减少与家庭供暖相关的二氧化碳排放。一种氨-水吸收技术已商业化，具有良好的GUE（气体利用效率，热量输出/气体输入的总热值约1.4），但资金成本较高。氨-碳吸附循环正在开发中，可将 GUE 降低至 1.2，但资本成本可承受。存在两种在不大幅增加资本成本的情况下改进吸附循环 GUE 的可能性。一种是碳氨技术的发展，采用具有改进的热回收的多个吸附器，另一种采用化学吸附剂，通常是嵌入石墨基质中并用于再吸收循环的卤化物盐。两者都是沃里克大学前期工作的主题。该研究项目将首先进行充分的分析和建模，以确定活性炭或金属卤化物吸附剂类型中哪一种更有最终商业应用的潜力。碳吸附剂当然可以达到 1.4 的 GUE，但代价是增加一些额外的复杂性。金属盐路线的技术成熟度较低，但理论上可以在二盐循环中提供 1.5 的 GUE，在三盐循环中提供 2.0 的 GUE。两种技术所面临的挑战有些不同。碳吸附剂已被充分表征和理解。难点在于构建热质量低、传热传质好、成本低的碳氨吸附器；这已经是多年来努力的主题。具有先进热回收功能的多床进一步增加了设计和模拟的复杂性。金属盐系统中的吸附剂非常不同，因为盐包含在导电（非吸附）石墨基质中，从而提高了电导率。再吸收循环还具有组件较少的优点。然而，发生的化学反应问题更大，反应速率很难预测。碳-氨机器中的活性炭始终处于化学平衡，并且操作受到传热限制，而在金属盐-氨系统中，永远不会达到平衡，操作性能取决于对反应速率动态知之甚少。两项竞争技术（预计在第 9 个月）该研究将进入详细设计和模拟阶段，其中使用沃里克大学已经建立的大温跃 (LTJ) 技术在“单元”水平上评估拟议的吸附器设计。随着吸附器设计的验证，概念验证机器（3-10 kW 输出）的建造将开始，并开始控制策略的模拟。 POC 机器将首先在 ThermExS 实验室进行测试，该实验室是在 EPSRC 资金拨款下专门建造的，旨在轻松评估新型热力学系统。它由四个计算机控制的热浴、阀门和泵组件组成，充当 -10 至 180 C 的热源和散热器，功率为 7 至 30 kW。这种水平的电加热测试和实验室内的测试足以证明所选择的循环/吸附剂并产生值得攻读博士学位的新知识。然而，到那时沃里克很可能会有新资助的项目，使这项工作能够进一步推进，也许与独立系统中的燃气燃烧器集成。