【作者】 黄锋；

【导师】 郑洁；

【作者基本信息】 重庆大学 ， 供热、供燃气、通风及空调工程， 2017， 博士

【摘要】 现代工业园区通常采用分布式能源系统作为配套的能源基础设施以满足工业生产和维持园区日常运转的需求。分布式能源项目规划和设计遵循能源梯级利用的原则,随着余热回收技术的发展,越来越多的低品位余热能够被回收利用以提高系统的综合能效。本文针对以云计算产业为核心的工业园区(简称:云计算产业园)的负荷特性和余热特征,依托科技部中荷国际科技合作项目“智慧节能工业园关键平台技术与协同驱动”(2015DFG62270),开展工业园区分布式能源系统低品位工业余热利用和综合评价体系的研究。首先,基于低品位工业余热用于区域供热的研究现状,提出了冷热电联供与区域供热系统耦合的CCHP-DH(Combined Cooling,Heating and Power coupled with District Heating)系统典型配置,并阐述了CCHP-DH系统如何在园区实现能源梯级利用。在低品位工业余热资源循环化利用模式研究中,建立了从多热源取热的优化模式:多热源并联、串联和混联布置模式,并进行热力学分析;分析了低品位工业余热用于区域供热系统的低品位热源侧远距离输配问题,主要包括输配能耗和输送热损失分析;提出了利用低压蒸汽对低品位工业余热用于区域供热的系统调峰模式。其次,基于利用多个换热器才能实现从多热源取热的现状,研发了一种可实现多热源余热回收的换热装置,该换热装置的特点是余热回收系统的热媒水可以同时从多个热源取热,灵活调节热源的个数及每个热源与热媒水的换热面积,以降低换热过程的热损失。再者,通过调研重庆市分布式能源项目发展现状可知,工业园区分布式能源项目进入快速发展阶段,然而伴随产生的大量低品位工业余热并未得到有效利用。此外,采用问卷调查的形式,从居民的冬季采暖现状、区域供热的意愿及预期的费用等方面,了解生活在典型夏热冬冷地区的重庆居民的区域供热需求和意愿,从而分析在重庆市发展区域供热的机遇和挑战。建议工业余热供热优先为分布式能源项目所在的工业园区内建筑提供服务,并辐射至周边居民社区,这样既降低工业余热对周边环境的影响又能满足居民区域供热的意愿。再者,基于案例分析,在解决多热源低品位工业余热用于区域供热关键问题过程中,归纳了低品位工业余热热源信息,并对七种不同制热工况进行热泵选型,结果表明案例中的低品位余热热源最多可对外供热135MW。在制热工况四,用10台9000kW的热泵回收3台吸收式制冷机组冷却水和热电厂部分循环冷却水的余热,可满足园区及其附近区域的用户供热需求,水泵能耗为3090kW,输配过程供水管热损失为56.366kW,并分析了低压蒸汽调峰量。再者,对比分析了两种不同的低品位余热回收方式在CCHP-DH系统和CHP-DH系统中的应用,一种是利用压缩式热泵提升余热的品位用于区域供热;另一种是抽取一部分蒸汽经汽-水换热器提升余热的品位用于区域供热。就能源性能而言,在CCHP-DH模型中,在供电、蒸汽供热、区域供冷、区域供热方面,前者的性能都优于后者;在CHP-DH模型中,两种余热回收方式下的系统综合能源效率相近,尽管后者消耗一部分低压蒸汽用于提升余热的温度,导致其工业供热量和供电量比前者少,但前者在运行过程中,压缩式热泵消耗了较多的电能。再者,利用THERMOPTIM软件对案例园区的分布式能源系统,按照规划的CCHP-DH模式进行模拟分析。但在实际建设和运行过程中,园区可能出现不同的冷、热、电和区域供热需求组合,因此利用情景分析法,建立了CCHP-DH系统在不同情景下的模型:CCHP-DH,CCHP,CHP-DH和CHP,进行3E性能对比分析。本对比分析既可用于追踪系统从CHP发展到CCHP-DH过程中,各个阶段的性能,又能为系统在分阶段建设或运营中,根据园区动态更新的能源需求调整系统的能源输出和能源价格时,提供量化的参考。最后,建立分布式能源项目的综合评价体系,并通过实例验证其合理性和有效性。该体系包括基于外边界分析和内边界分析的系统综合性能评价和基于利益相关者分析的项目发展障碍评价。1)在综合性能评价方面:首先,在外边界分析中,建立了表示经济价值比、能源价值比和余热排放比的三维坐标用于对分布式能源系统进行整体的评价。在案例评价中,V01模型的综合性能最优。其次,在内边界分析中,利用转化因子将系统的能源和环境价值转化为等价的经济价值,提出了综合考虑系统3E性能的量化评价指标。内边界分析有利于识别节能潜力较大的过程从而准确地通过改进系统的过程性能以达到优化整个系统综合性能的目的,采用余热回收系统对分布式能源系统的综合性能评价有积极的影响。2)在发展障碍评价方面:利用利益相关者分析法定义和识别项目全生命周期的不同利益相关者:核心利益相关者、主要利益相关者和一般利益相关者。案例评价过程中,基于专家评价法,利用利益-影响力矩阵来识别不同的利益相关者。结果表明:电厂的所有者/运营商、一次能源供应商及电网运营者是案例项目在全生命周期中的核心利益相关者。此外,基于案例的发展障碍评价结果,提出了有效的应对策略,用于解决核心利益相关者间的利益冲突和平衡不同利益相关者间的利益关系。更多还原

【Abstract】 Distributed Energy System(DES)is commonly installed as energy infrastructure of industrial parks to meet energy demand of industrial production and daily operation.The plan and design of DES system follows the rule of energy cascade utilization.As the development of waste heat recovery technologies,more and more low-grade waste heat can be recovered to improve comprehensive energy efficiency of DES system.The research on low-grade waste heat utilization and comprehensive evaluation of DES system is carried out according to the characteristic of energy demand and waste heat of the industrial park,which is characterized by Cloud Computing industry(so-called Cloud Computing industrial park).To begin with,based on the research status of industrial waste heat recovery for District Heating(DH),typical configuration of CCHP-DH system is proposed based on the combination of CCHP system and DH,which is illustrated step by step to show how to realize energy cascade utilization in industrial park.In the study of waste heat recovery,three types of optimal configuration of multi-waste heat sources are proposed and analyzed using thermodynamics method,i.e.multi-waste heat sources in serial,in parallel and in mixed arrangement.The distribution issue of low-grade waste heat on the heat-source side of DH system is analyzed mainly including the study of energy consumption and heat loss in the long-distance distribution.Besides,low-pressure steam is proposed to settle down peak-shaving issue of DH system based on low-grade waste heat recovery.Then,according to the current state of using multiple heat exchangers to recover multi-souce waste heat,a new heat exchange unit is designed with the function of recovering waste heat from multi-waste heat sources simultaneously and adjusting the number of waste heat sources and the area of heat exchange flexibly.Then,according to the investigation of the development status of DES projects in Chongqing,it is known that DES projects in industrial parks are experiencing rapid expansion.However,a large amount of low-grade industrial waste heat from industrial park has not yet been recovered in an effective way.Besides,based on the questionnaire in terms of space heating status,the will for DH and expected cost for DH etc.,the expectation and requirement of DH for residents living in Chongqing are acknowledged.Then,the challenge of developing DH in Chongqing is analyzed and the suggestion is proposed to develop waste heat driven DH preferentially for end-users in industrial park,which can be expanded to people living around the industrial park.Then,in the process of figuring out key issues of recovering multiple low-grade industrial waste heat for DH,low-grade industrial waste heat is identified and heat pump selection is carried out for seven heating conditions,respectively.The result shows by recovering all the low-grade industrial waste heat of industrial park of Case study will supply heating up to 135 MW.In the fourth heating condition,10 units of heat pumps at heating capacity of 9000 k W/unit are used for recovering the waste heat of cooling water of thermal power plant and 3 units of absorption refrigerators.The recovered waste heat can meet heating demand of buildings located in and near the industrial park based on energy consumption of 3090 kW for water pump and heat loss of 56.366 kW in water delivery by using water pipe.Besides,the amount of low-grade steam used for peak-shaving is analyzed.Then,two modes of low-grade waste heat recovery applied in CCHP-DH system and CHP-DH system is compared and analyzed.One is waste heat recovery for DH using compression heat pump and the other is waste heat recovery for DH using heat exchanger with the extraction of a certain amount of low-pressure steam.In terms of energy performance of,the former mode applied in CCHP-DH model performs better than the latter in the supply of power,industrial heat,district cooling and DH,however,comprehensive energy efficiency of the former mode is higher than the latter by 3.76%.The main reason is that compression heat pump consumes a certain amount of in the former mode.Besides,two modes of waste heat recovery perform similarly when applied in CHP-DH model.Then,THERMOPTIM software is applied to simulate DES system of Case Study in the form of CCHP-DH model.However,there are different energy demand groups of cooling,heating and DH in the process of the construction and operation of CCHP-DH system,so different scenarios are proposed,i.e.CCHP-DH,CCHP,CHP-DH and CHP,to carry out comparative analysis of 3E performance.Thus,comparative analysis can be used to trace 3E performance of DES project of Case Study from CHP model to CCHP-DH model,as well as to make a qualified reference for adjusting the energy output and price of DES project according to the renewed energy demand in the process of construction and operation.Finally,comprehensive evaluation system is established for DES project and Case Study is used to validate its rationality.The evaluation system includes comprehensive performance evaluation of DES project using Outside Boundary(OB)analysis and Inside Boundary(IB)analysis,and barrier evaluation of the sustainable development of project using Stakeholder Analysis,which is illustrated in detail as follows:1)Comprehensive performance evaluation: In OB analysis,three-dimension coordinate is established to show the general performance of DES system.It potentially shows more favorable and feasible option by comparing potential configurations of the project.As a result,V01 has the most favorable performance.In Inside Boundary(IB)analysis,relative 3E index is introduced to evaluate DES comprehensively considering 3E performance by transferring energy performance indicator and environmental performance indicator into economic performance indicator for the purpose of the unification of 3E performance indicators.IB analysis is beneficial to detect the process improvement precisely,and waste heat recovery has a promising impact on comprehensive performance of DES system.2)Barrier evaluation: interest-influence matrix of Stakeholder analysis is used to identify different stakeholders,i.e.core stakeholders,primary stakeholders and general stakeholders in life cycle of DES project.Consequently,the Owner/Operator of Power Plant,Primary Energy Provider and Power Grid Controller are identified to be core stakeholders during the life cycle in this DES project,so their interests should be seriously considered in each process of developing DES project.更多还原