空气源热泵与燃气锅炉供暖能耗对比分析

随着清洁能源供热应用的推广,能耗成本将成为选择热源方式的重要依据之一.以河北省霸州市A小区实际供暖项目为例,对安装空气源热泵前后2个采暖季的能耗成本进行比较分析,再结合理论,对空气源热泵系统和燃气锅炉2种供暖方式的运行成本进行了详细分析.总结出在霸州地区以及燃气价格相近的北方寒冷区域,空气源热泵的优势比燃气锅炉的优势更...     

广东典型工业园区燃气分布式能源供能经济可行性分析研究

以广东省珠三角地区某工业园区为例进行了典型燃气分布式能源站方案经济性分析,以用能企业自建燃气锅炉为基准进行了经济性对比,结果显示针对燃气分布式能源项目,影响收益的敏感性因素主要是上网电价及天然气价。在上网电价较为明确的情况下,燃气分布式能源可与负荷用户签订气热联动条款以疏导气价波动风险,但是如天然气价格上涨过高将导致能源站供热价格超过负荷用户自建燃气锅炉供热成本,为合同签订带来较大风险。     

吸收式热泵在燃气锅炉烟气余热回收中的应用实践

针对某地燃气锅炉项目,选择吸收式热泵回收烟气余热。根据计算,烟温从80℃降至30℃时,烟气余热量约9.38 MW,可将系统效率提高11.1%。并根据供热延续曲线、燃气价格、热泵投资等计算不同规模热泵下的供热成本,确定最佳热泵型号。采暖季运行结果显示:该技术可以节约燃气消耗,系统效率提高约8.5%,具有很好的经济效益、环保效益。     

城市燃气锅炉房供热能力和余热利用

为了提取余热提升城市供热能力,介绍了郑州市燃气锅炉房供热现状和基于直接接触换热的烟气余热深度回收新技术,并对燃气锅炉供热能力进行了统计和分析。发现通过对燃气锅炉烟道改造和余热回收,燃气锅炉房的供热能力将达到1 600 MW,供热面积为0.35亿m~2,同时烟气中NO_x和SO_2得到有效减排,具有显著节能效果和经济效益。     

M701F4型燃气-蒸汽联合循环供热机组停机后利用高压汽包余热供热探讨

介绍了M701F4型燃气-蒸汽联合循环供热机组两班制运行情况下,机组在停机后利用高压汽包余热对外进行供热,在不影响机组的安全,推迟了燃气锅炉的启动时间,提高了经济性。     

燃气锅炉供热系统提升能效改造方法——基于实测工程案例分析

针对燃气锅炉集中供热存在的问题,总结一套评价并提升燃气锅炉供热系统能效的方法。从设备效率、运行策略、能耗预测等方面进行分析评价,最后提出节能改造措施,应用在燃气锅炉系统节能改造的实例上,为燃气锅炉供热系统的改造和运行提供参考。     

直燃型吸收热热泵回收燃气锅炉烟气余热技术的应用探讨

对目前常用的燃气锅炉余热回收技术进行了介绍。针对直燃型吸收热热泵回收烟气余热技术进行了理论研究,给出了燃气锅炉在某负荷下的余热计算方法,并编制了烟气焓温表。研究表明:燃气锅炉负荷1 MW时,烟气温度从80℃降至30℃时,回收余热负荷约0.1 MW,回收余热负荷约占锅炉负荷10%。在实际工程应用中,提出了燃气锅炉+直燃型吸收热热泵热价计算方法。研究表明:该技术可以有效降低供热成本,随着燃气价格等因素不同,存在一个最佳的回收比例。     

化工区多热源协同供热成本和优化分析

研究工业热网多热源协同供热成本计算和供热优化问题,采用微增利润法计算多热源的供热成本,在保证各热用户供热质量的前提下,结合热网结构与热负荷情况,合理分配多个热源间的供热比,以达到经济效益最大化的目标。采用的微增利润法具有计算方便简单、定义清晰简明等优势,适用于燃气轮机联合循环、燃气锅炉、燃煤火电等机组多热源协同供热,并可指导运行人员对工业热网进行运行与调度。     

燃气轮机热电联供系统性能评估案例

对某供热厂的燃气轮机热电联供系统进行了研究,将燃煤分产和燃气分产进行了全方面的比较,其性能评价对合理应用CHP有重要作用。在热电分产的节能性方面,以燃气-蒸汽联合循环电厂和燃气锅炉作为比较的基准线,全年平均节能率为8.9%;在运行经济性方面,燃气轮机系统与燃煤锅炉分产相比,每年节省46万元,与燃气锅炉分产相比,每年节省182万元,且节省费用随着电价的增加而增加,随着气价的增加而减少。另外,与燃煤锅炉分产相比时,还随着煤价的增加而增加;在排放物方面,燃气轮机联供系统与燃煤分产和燃气分产对比,NOx减排量并不显著,而其余排放物有明显地减少。燃气轮机系统与燃煤以及燃气锅炉相比具有一定的优越性,在设计合理的情况下具有良好的前景。     

基于吸收式换热的深层地热集中供热系统能效分析

结合深层地热温度高、稳定性好的特点,提出基于吸收式换热的深层地热集中供热新系统,并对其热力性能及经济性进行分析。结果表明:远低于地热水温的一次网回水有助于热源站采用换热器高效利用深层地热能。当一次网输热距离为15 km时,新型供热系统的产品效率为22.94%,一次能源利用率为121.6%,供热成本为62.25$/GJ,投资回收期不足7 a。与常规燃气锅炉供热系统相比,新型供热系统每年可降低燃气消耗量约54%,供热成本约25.6%;提升产品效率约11.8%,一次能源利用率约63.2%。     

高效燃气热水器的实验研究和节能分析

介绍了研制的新型家用燃气热水器和热水炉（兼有热水供应和采暖的功能）其特点是：冷凝传热和低污染燃烧技术。对家用燃气热水器和热水炉进行了实验研究，在不同运行工况下测定了热水器的热效率和NOx及CO的排放量，并与传统热水器进行了对比分析。实验结果表明，新型家用燃气热水器及热水炉具有高热效率和低污染排放的特点，它能大大降低对环境的污染。     

50MW高压锅炉全燃高炉煤气的研究

对50MW高压锅炉全燃高炉煤气时的特性进行了详细讨论。阐述了高炉煤气锅炉稳定着火燃烧的燃烧技术和结构特点,分析了燃用高炉煤气对锅炉热工参数、传热特性以及受热面布置的影响,提出了适用高炉煤气的锅炉布置型式。根据研究结果制造的我国首台50MW高炉煤气的锅炉布置型式。根据研究结果制造的我国首台50MW高炉煤气高压锅炉成功运行的实践证明,该可以有效解决高炉煤气放散污染问题,在冶金工业中有着广阔的应用前景。     

Evaluation of retrofitting a conventional natural gas fired boiler into a condensing boiler

The exit flue gas temperature of a conventional gas fired boiler is usually high and a great amount of heat energy is lost to the environment. If both sensible heat and latent heat can be recovered by adding a condensing heat exchanger, the efficiency of the boiler can be increased by as much as 10%. In this paper, based on combustion and heat transfer calculations, the recoverable heat and the efficiency improvement potential of different heat recovery schemes at various exit flue gas temperatures are presented by performing design calculations. The payback period method has been used to analyze the feasibility of retrofitting a conventional gas fired boiler into a condensing boiler in a heating system in detail. The results show that the most economical exit flue gas temperature is 40–55 °C when a conventional natural gas fired boiler is retrofitted into a condensing boiler simply by adding a condensing heat exchanger. It is feasible to use the return water of a heating system as the cooling medium of the condensing heat exchanger because the return temperature varies with the ambient temperature and is lower than the dew point of the water vapor in the flue gas in most periods of a heating season in some regions, which has been verified by retrofitted case.     

Utilization of combustible waste gas as a supplementary fuel in coal‐fired boilers

A system is proposed to use the combustible waste gas as a supplementary fuel in coal‐fired boilers. The combustion air can be partially or fully substituted by ventilation air methane or diluted combustible waste gases. The recommended volume fraction of combustible waste gas in combustion air is no more than 1.0%. The effect of waste gas introduction on thermodynamic parameters of boiler is evaluated through thermal calculation based on material balance, heat balance, and heat transfer principles. A case study is conducted by referring to a 600 MW supercritical pressure boiler. The results show that no retrofit of boiler is required. The operation of boiler is scarcely influenced, and the original forced and induced draft fans can meet the requirement. With increasing volume fraction of combustible waste gas, the flue gas temperature at the furnace exit decreases monotonically, resulting in an increment of heat absorption in furnace and a decrement of heat transferred in convective heating surfaces. When 1.0% volume fraction of hydrocarbon gas is introduced, the thermal efficiency of boiler is increased by 0.5%, and the coal consumption rate is reduced by 25.4%. The cost analysis of the proposed system is conducted, and break‐even curves are given as references for the utilization of waste gas as a supplementary fuel. The economic velocity of the combustion air is suggested to be 18.2 m s^?1.     

小型工业锅炉烟气余热利用新技术

针对目前小型燃煤工业锅炉排烟温度高、排烟热损失大,用户管理和操作水平低,运行中通常间断式给水的情况,设计了两种利用烟气余热进行节能改造的无压装置。在锅炉运行时,通过无压换热器的换热、水箱中水的蓄热来降低排烟温度、提高锅炉效率。改造后的锅炉在稳定工况、低负荷工况下的测试结果证明,锅炉效率均显著提高。回收周期的计算表明,应用该技术投资少、回收周期短。     

116MW水冷方形分离循环流化床热水锅炉的运行经验

城市燃煤集中供暖对洁净燃烧技术的需求是循环流化床热水锅炉发展的动力。介绍了首台运行的最大容量的116MW循环流化床热水锅炉的运行情况。实践表明：采用水冷方形分离器的116MW循环流化床热水锅炉运行稳定,可用率高,燃烧效率高,满足严格的大气排放标准,密封性好,占地面积小,可以很好地适应城市集中供暖频繁启动和压火的需要。图6表5参6     

介质热管锅炉供热技术

文中介绍了介质热管锅炉供热系统的工作原理，设计方法，施工运行要求和主要特点，并给出了介质热管锅炉供热系统与热水锅炉供热系统在初投资及运行维护费用方面的比较结果。     

具有混合气体冷凝的燃气锅炉系统

介绍了常用的冷凝型锅炉结构,重点讨论分离式冷凝锅炉的特点。天然气锅炉烟气中含有相当比列水蒸汽,携带大量汽化潜热,与燃煤锅炉明显不同,提供了更大的余热利用空间。针对燃天然气热水锅炉,研制开发了采用烟气冷凝热能回收装置的锅炉系统并应用于实际。运行测试表明,改造的锅炉运行正常,提高锅炉热效率5%以上,节约大量天然气,同时吸收烟气中部分NOx,起到一定净化作用。本系统投资回收期短,节能与环保效益显著。     

天然气锅炉改造为冷凝式锅炉的经济性评价

燃气供热锅炉排烟温度较高，带走了大量的热能。如果加装冷凝式换热器回收烟气的显热及潜热，可以大大提高锅炉效率，但是加装换热器必然增加设备成本。本文通过对冷凝式换热器设计计算，计算出不同排烟温度下的热能回收设备投资回收期，从经济上分析了天然气锅炉改造为冷凝式锅炉的可行性，并给出了锅炉最佳排烟温度。     

Analysis of two‐stage waste heat recovery based on natural gas‐fired boiler

Waste heat recovery (WHR) is crucial to the efficiency improvement of natural gas‐fired boiler systems. Two‐stage WHR systems based on the natural gas‐fired boiler were analyzed from the viewpoints of thermal efficiency and heat transfer irreversibility. An overall entransy dissipation‐based thermal resistance was derived to evaluate the irreversibility of WHR, including the entransy dissipations during condensation and in absorption heat pump (AHP). Compared with the basic WHR system, the two‐stage WHR systems have higher boiler efficiency and less irreversibility. The air‐humidified system recycles both the heat and vapor in flue gas, while the unutilized latent heat in the recovered vapor causes the boiler to be less efficient than the AHP system. Investigation on heat exchanger effectiveness of two‐stage WHR systems illustrated: in the two‐stage WHR system with air humidification, the increasing effectiveness of both heat exchangers could effectively increase boiler efficiency and reduce heat transfer irreversibility. In the two‐stage WHR system with AHP, boiler efficiency has a local optimum when the dew point occurs near the outlet of the first heat exchanger; increasing the second heat exchanger effectiveness is more efficient in improving boiler efficiency. The present work may provide available references and guidance for the design and optimization of the two‐stage WHR systems.