大型热电肥联产沼气发电工程分析

从工艺流程、技术参数、运行状况以及效益分析等方面对现今国内畜禽场规模最大的沼气发电工程进行技术分析。运行表明,通过全混式厌氧发酵（CSTR）两级工艺,纯鸡粪进行厌氧发酵沼气发电是确实可行的;该工程的成功既解决了鸡粪污染,又产生了巨大的经济社会效益,对实现畜禽粪便综合利用具有良好的示范效果,并可为同类型沼气发电工程设计和建设提供参考。     

沼气与液化石油气热电联产试验对比研究

通过搭建小型实验平台,对基于燃气内燃机的热电联产系统在不同燃料下的机组性能和系统性能进行了探究。通过测得的发电功率和燃气流量计算出燃气发电机在不同负荷下的发电效率和燃烧功率,进而计算出不同燃料下热电联产系统的系统总效率并加以比较。试验结果表明,燃气内燃机组的发电效率和系统总效率随着电负荷的增大而增大;使用沼气作为燃料时,系统总效率最高可达到46.96%,高于使用液化石油气作为燃料时的系统总效率;用电负荷是影响系统各种效率的主要因素之一。     

餐厨垃圾沼气热电联产经济分析

餐厨垃圾是典型的高有机质、高水分及高盐分废弃物,危害性和资源可利用性并存。若不能正确处理,极易腐烂变质甚至传播细菌和病毒。青岛某公司为实现餐厨垃圾无害化处理,采用高温湿式单相连续厌氧发酵热电联产技术,探索将餐厨垃圾转化为生物柴油、燃料酒精、沼气、有机肥、土壤改良剂和饲料添加剂等物质的有效方法,同时实现了废弃物的减量化、无害化以及能源化。文中结合该公司实际现状,探讨厌氧发酵技术在餐厨垃圾处理方面的潜力和优势,为餐厨垃圾的无害减量化处理找到更好的发展方向。     

“气热电肥联产”模式秸秆沼气工程探索与经济效益分析——上实农业园生物质循环利用示范工程模式解析

位于上海崇明上实园区的东滩绿港生物质循环利用示范工程通过运用"气热电肥联产"模式,可实现日处理秸秆干物质4 t,牛粪12 t,年产沼气约3.6万m3,发电58.4万kW。其中,电能用于园区内生活和生产用电,部分沼气和发电机组余热用于冬季厌氧罐的增温和景观温室大棚供暖,发酵后的沼渣、沼液用于有机肥生产,实现了农业废弃物的多层次循环利用。阐述了该生物燃气工程循环利用的工艺流程及关键技术,并对其经济效益进行了评价,旨在为长三角地区农业废弃物资源化利用提供理论参考。     

污水厂热电联产工程效益分析

青岛某污水厂每天进水量约为14.5万t,该厂污水处理采用"中温厌氧消化+热电联产"工艺。文中通过对该厂设备正常运行数据,其中包括日处理污水量、污泥量、沼气产量、效益及发电量等进行了系统整理与分析,由于该污水厂采用厌氧消化技术,并通过回收发电机烟气余热和缸套水余热来加热消化池,该技术的应用不仅节约了该厂能源消耗,而且还提高了产气的稳定性。由于该厂沼气发电量为厂内自用,因此,该厂还节省了约22%的购电费用。     

热电联产机组节能发电组合研究

通过对国家有关热电联产政策的分析,结合背压式汽轮机、一次抽汽式汽轮机的热能利用原理和热力特性,讨论了抽汽式汽轮机“以热定电”的含义,提出按照节能运行方式确定中长期发电组合（发电计划）,按照安全运行方式确定短期发电组合（发电调度）的方案,发电考核时将热电联产机组发电量分解为热化发电量、奖励发电量、计划内凝汽发电量、计划外发电量4种不同成分分别考核。     

12MW生物质直燃发电的热电联产系统节能经济性分析

以山东阳信市某企业生物质直燃发电的热电联产系统为研究对象,以其热、电负荷计算为基础,进行了主要设备的选型匹配。同时从标准煤耗量、年均总热效率和成本节约三个方面对系统进行节能经济性分析,指出了热电厂梯级利用能量的意义。分析结果表明：实施热电联产后系统年均总热效率达到60.9%,较中小型纯凝机组的提高约25.9%;在企业年生产总量不变的条件下,年节约标准煤约35352t,极大地节约了生产成本,具有可观的经济效益。     

建设燃气热电联产机组替代燃煤小热电的必要性

以《张家港市热电联产规划（2011～2015）》为蓝本,从发展燃气-蒸汽联合循环热电联产、减少环境污染、节能减排入手,解读了张家港市热电联产实施方案及改善电源结构,走绿色电网可持续发展之路.通过分析张家港市的地区供热和电网现状、电力平衡,得出远期热负荷增加明显的片区是主城片区和城北片区.在对新增热负荷预测的基础上,提出整合主城片区现有热源点,关停供热覆盖范围内小锅炉,依托华兴电力有限公司建设2台F级400MW燃气热电联产机组,替代主城片区燃煤小热电是可行、合理的.这对满足地区可持续发展需要和节能减排,具有重要意义.     

热电冷联产系统的热经济性分析

从能分析和火用分析两方面对热电冷联产系统的热经济性进行计算和分析,采用等效发电效率、等效发电火用效率与发电煤耗三种评价方法,以找出能量利用的薄弱环节,提高能源利用效率。     

垃圾焚烧电厂热电联产的经济性分析

合理利用垃圾资源进行热电联产,是节能减排、改善环境的有力措施。以某2×750 t·d^-1垃圾焚烧电厂为例,通过模型研究发现热电联产可以减少垃圾焚烧电厂的冷源损失,提高全厂热效率;利用一抽蒸汽进行热电联产可实现蒸汽品质的梯级利用,获得较高的经济效益;供热量为30 t·h^-1,垃圾热值由4185.9 kJ·kg^-1增加至8371.7 kJ·kg^-1时,发电量越多,供热能力越强,年热电联产经济效益由7822.76万元增加到14641.07万元;垃圾热值为8371.7 kJ·kg^-1,供热量从10 t·h^-1增加到60 t·h^-1时,垃圾焚烧电厂热效率从28.96%增加到48.50%,年经济效益从13602.74万元增加到15455.66万元。当该地区垃圾热值较高并具备供热条件时,实现垃圾热电联产具有较高的收益。     

Evaluation of the performance of combined cooling,heating, and power systems with dual power generation units

The benefits of using a combined cooling, heating, and power system with dual power generation units (D-CCHP) is examined in nine different U.S. locations. One power generation unit (PGU) is operated at base load while the other is operated following the electric load. The waste heat from both PGUs is used for heating and for cooling via an absorption chiller. The D-CCHP configuration is studied for a restaurant benchmark building, and its performance is quantified in terms of operational cost, primary energy consumption (PEC), and carbon dioxide emissions (CDE). Cost spark spread, PEC spark spread, and CDE spark spread are examined as performance indicators for the D-CCHP system. D-CCHP system performance correlates well with spark spreads, with higher spark spreads signifying greater savings through implementation of a D-CCHP system. A new parameter, thermal difference, is introduced to investigate the relative performance of a D-CCHP system compared to a dual PGU combined heat and power system (D-CHP). Thermal difference, together with spark spread, can explain the variation in savings of a D-CCHP system over a D-CHP system for each location. The effect of carbon credits on operational cost savings with respect to the reference case is shown for selected locations.     

Ensuring emergency power for critical municipal services with natural gas-fired combined heat and power (CHP) systems: A cost–benefit analysis of a preemptive strategy

Electric power failures in the aftermath of disasters cripple the delivery of critical emergency services. While emergency generators are available in some facilities, these systems are designed for short-term use and support limited functions. The substantial investment required to ensure emergency power for all critical services is difficult to justify because of the uncertainty associated with the likelihood and magnitude of future disasters. Investment evaluations change when a new source of emergency power is considered. This study evaluates the costs and benefits of a program to preemptively install new building-sited electric combined heat and power (CHP) generation technologies to ensure reliable long-term power for critical municipal services in hurricane-prone regions of the US. Three municipalities are selected for this analysis: Houston, Texas; Miami, Florida; and Charleston, South Carolina. Analysis indicates that costs of such a program can, in some cases, provide net energy bill savings regardless of the occurrence of a disaster.     

垃圾焚烧热电联产蒸汽参数选择

针对垃圾焚烧热电联产时,采用中温中压及中温次高压蒸汽参数对全厂投资及经济性的影响进行研究。以日处理规模为600 t·d^-1的生活垃圾焚烧设施作为研究对象,从主机设备参数、主机设备投资额、经济指标、营业收入及投资回收期等5个方面进行分析。研究结果表明,采用中温次高压参数时,垃圾焚烧设施热电联产全厂热效率较采用中温中压参数时提高1.7%,热电联产时全年总收入较采用中温中压参数时提高11.5%,且经济性更好,静态投资回收期约为4.73年。     

Should a small combined heat and power plant (CHP) open to its regional power and heat networks? Integrated economic,energy, and emergy evaluation of optimization plans for Jiufa CHP

The development of industrial ecology has led company managers to increasingly consider their company's niche in the regional system, and to develop optimization plans. We used emergy-based, ecological-economic synthesis to evaluate two optimization plans for the Jiufa Combined Heat and Power (CHP) Plant, Shandong China. In addition, we performed economic input–output analysis and energy analysis on the system. The results showed that appropriately incorporating a firm with temporary extra productivity into its regional system will help maximize the total productivity and improve ecological-economic efficiency and benefits to society, even without technical optimization of the firm itself. In addition, developing a closer relationship between a company and its regional system will facilitate the development of new optimization opportunities. Small coal-based CHP plants have lower-energy efficiency, higher environmental loading, and lower sustainability than large fossil fuel and renewable energy-based systems. The emergy exchange ratio (EER) proved to be an important index for evaluating the vitality of highly developed ecological-economic systems.     

Combined heat and power systems with dual power generation units and thermal storage

The objective of this paper is to study the performance of a combined heat and power (CHP) system that uses two power generation units (PGU). In addition, the effect of thermal energy storage is evaluated for the proposed dual‐PGU CHP configuration (D‐CHP). Two scenarios are evaluated in this paper. In the first scenario, one PGU operates at base‐loading condition, while the second PGU operates following the electric load. In the second scenario, one PGU operates at base‐loading condition, while the second PGU operates following the thermal load. The D‐CHP system is modeled for the same building in four different locations to account for variation of the electric and thermal loads due to weather data. The D‐CHP system results are compared with the reference building by using conventional technology to determine the benefits of this proposed system in terms of operational cost and carbon dioxide emissions. The D‐CHP system results, with and without thermal storage, are also compared with that of single‐PGU CHP systems operating following the electric load (FEL), following the thermal load (FTL), and base‐loaded (BL). Results indicate that the D‐CHP system operating either FEL or FTL in general provides better results than a single‐PGU CHP system operating FEL, FTL, or BL. The addition of thermal storage enhances the potential benefits from D‐CHP system operation in terms of operational cost savings and emissions savings. Copyright © 2013 John Wiley & Sons, Ltd.     

Photobiostimulation of anaerobic digestion by laser irradiation and photocatalytic effects of trace metals and nanomaterials on biogas production

Biogas generation from the latent energy in biomass is one of the most attractive renewable energy sources. This can be attributed to the environmental friendly nature of the process and its less energy requirements. This article reviews the anaerobic digestion of biomass (livestock manure and crop residues) for biogas and methane production as a source of renewable energy. Furthermore, this study investigates the enhancement of biogas and methane production using light and laser radiations. The laser radiation accelerates bacterial division and growth, where this process is termed as “photobiostimulation.” Additionally, laser radiation photoactivates the inactive enzymes. The results of this literature review showed that the irradiation of methanogenic bacteria with laser sources increased the biogas production by one and a half fold the traditional method of biogas production. The simultaneous irradiation of both nanomaterials and methanogenic bacteria using laser radiation increased the biogas volume by twofolds the biogas volume resulted from the traditional method of biogas production.     

葡萄籽提油前后发酵产沼气潜力研究

在恒温25℃条件下,采取批量发酵工艺,研究了葡萄籽提油前后产沼气潜力。结果表明:葡萄籽TS,VS发酵产沼气的潜力分别为473.65 mL/g和484.55 mL/g,能源转换效率为37.25%;葡萄籽油枯TS,VS发酵产沼气的潜力分别为450.03 mL/g和460.44 mL/g,能源转换效率为36.43%。