渤三联合站分布式能源系统夹点分析

为了解决胜利油田能源消耗较大,余热浪费较多的问题,提出天然气发电和污水余热利用相结合的联合站分布式能源系统。构建了分布式能源系统核心设备的能流模型,利用能流分析的方法对核心设备在不同运行参数下的性能进行分析。以能流分析为基础,利用实际运行参数对渤三联合站分布式能源系统进行夹点分析,确定出夹点位置以及最小负荷。最终,计算得到调优改造后换热网络的节能潜力。结果表明：较优的夹点温差范围为14~18 ℃;当夹点温差为18 ℃时,对应的联合站所需总费用最低,联合站所需要的加热量为8 901.8 kW,与夹点分析优化之前相比所需的热负荷下降了1726.7 kW,其节能潜力达到19.4%。     

常减压装置换热网络优化应用

常减压装置是炼油能耗大户,其用能水平的高低对炼油厂综合能耗有较大影响。而在完成装置核心工艺的用能优化基础上再进行换热网络优化,是常减压装置的节能重点。应用AspenPlus流程模拟软件,建立某炼油厂常减压装置及换热网络流程模拟模型,并应用热集成技术及夹点技术对装置进行用能分析,对常减压及换热网络进行热集成优化,提出操作优化方案和改造优化方案,提高常减压装置的用能水平和热回收水平。操作优化实施后,装置每年产生的实际经济效益为476.5万元。另结合夹点技术对换热网络进行了三个层面的分析,首先应用夹点技术绘制过程负荷性能图,查看换热网络有无违背夹点换热原则;然后查找有无交叉换热的换热器;最后对可利用的低温余热进行有效利用。提出了相应的改造优化方案,改造方案实施后,预计每年为企业节省400万元的操作成本。     

基于碳夹点分析法的可再生能源优化调度方法研究

为促进工业领域“双碳”目标的实现,结合“新增可再生能源不纳入能源消费总量控制”要求,通过使用大量绿电替代燃煤电力,可促进工业领域的节能降碳。文章首先建立碳夹点分析数学模型,并明确使用碳夹点分析法进行发电能源容量方案设计的各个步骤,查找相关标准计算常用发电燃料的二氧化碳排放因子。对于多区域间的可再生能源发电调度,进行单独区域碳夹点分析确定可再生能源增量,进而使用寻优算法完成区域间可再生能源电力优化调度。案例研究表明,文章所提出的基于碳排放夹点分析法的可再生能源优化调度方法有利于区域电网提高可再生能源使用率,从而增加高耗能企业绿电使用量,进而促进实现碳减排目标。     

聚氯乙烯装置热集成

聚氯乙烯装置是一个高耗能装置,对其利用夹点技术进行节能改造,有很重要的应用价值。本文利用夹点技术对某聚氯乙烯流程进行了分析,找出了其能量利用不合理的环节,针对这些不合理的环节提出了节能改造方案,并对方案进行了技术经济评价。     

夹点技术在LNG分馏换热能量优化中的应用

在天然气液化技术工程化研究中,LNG分馏工艺较复杂,且设备种类较多,存在热量利用不充分,公用工程消耗量大的问题,为了节约能源需要对换热网络进行改进。先使用HYSYS软件对分馏工艺进行模拟,得出系统工艺参数,分析现有换热网络能量消耗,得到最小换热温差,再运用夹点技术对分馏区换热网络提出了改造方案。通过改进和优化,充分利用脱乙烷塔底物流的冷量,将分馏区热公用工程消耗量降低了15%,冷公用工程消耗量降低了8%,使用夹点技术对系统工艺和设备参数优化的研究得到了良好的节能效果。     

氯乙烯生产中能量的优化集成

通过对换热网络夹点技术的分析应用,提出了公司氯乙烯装置用能的优化节能改造方案,进一步提高热能利用效率,肯定了运用过程系统能量的的优化集成技术所带来的节能效应,使企业达到降低能耗、增加效益、提高能源利用率的目的。     

夹点理论及其在换热网络中的优化分析

本文主要介绍了利用夹点技术设计换热网络的原则及需要注意的问题,并利用夹点技术对乙烯生产原有换热网络进行夹点分析,研究换热网络利用的瓶颈,找出换热网络不合理的环节和原因。经优化改造后新增4台换热设备,新增设备及改装费用约2 900万元,但每年节约公用工程费用2 949万元,回收期为一年,故改造合理,节能明显。     

炼油企业蒸汽动力系统的节能改造探析

本文介绍了一炼油企业的蒸汽动力系统合理用能,节能的一些优化改造措施,论述了从机组的优化配置到蒸汽的梯级利用改造方案,从对改造方案的技术经济评价中见,改造后节约了能源并显著提高了经济效益。     

夹点技术在氢气网络优化中的应用研究

随着国家对炼化企业的产品质量升级更新速率要求越来越快和对成品油质量要求越来越高,要求炼化企业对生产出来的汽柴油产品进行深度加氢,这就会消耗更多的氢气,如何将副产氢气利用效率最大化成为各炼厂首要解决的问题。通过夹点技术对某炼厂的氢气网络进行分析,找出了现行氢气网络存在的问题,利用夹点技术对公司现有的氢气网络进行优化调整。根据氢气夹点匹配原则,利用提纯装置生产出纯度高于夹点的氢气,把低品质存在余量的氢气提高纯度送到氢气管网,摒弃单一的氢气回收技术,采用膜分离技术和现有闲置装置的PSA进行耦合工艺,生产出≥99.5%的高纯氢,此技术不仅投资少,而且操作可靠性高,项目实施后现有的氢气管网得到了补充,相应的制氢装置负荷得到降低,优化后的氢气网络操作更加灵活,每年增加约2000t氢气,效益在2000万元以上。     

重催联合装置低温热水循环系统能量优化研究与实施

介绍某石化公司重油催化裂化联合装置低温热水循环系统能量优化方案。利用Petro-SIM软件,建立了重催联合装置全流程模型,并以最佳综合经济效益为目标,对重催联合装置换热器数据进行夹点技术分析,在充分研究夹点分析结果的前提下,利用模型,对装置低温热水循环系统当前实际生产运行数据进行评估计算,发现由于富气压缩机入口温度的瓶颈,低温热水循环既使用了循环水冷却,又使用了蒸汽加热,这才是导致低温热水循环引入了过多热量的原因。因此,依据分析结果,制定出优化方案,此方案不增加任何投资,仅需优化操作,在不影响气分装置产品质量的前提下,通过提高气分装置换热水低温位余热的使用效率,降低蒸汽消耗和循环水使用量。夹点技术分析及实际运行结果表明,该项目每年节省低压蒸汽59760t,每年节能4541.76t标油,每年增加收入539.51万元。     

“十一五”期间我国交通部门能源需求展望及节能潜力分析

本文首先介绍了我国交通用能展望和节能潜力分析的基本思路和方法,然后对"十一五"期间,交通部门在规划方案(7.5%的GDP增速)和高经济增长方案(9%的GDP增速)下的节能潜力、可能完成的节能量做了详细的定量分析和比较研究;最后在此基础上梳理、归纳了几点结论和建议。     

Variability of energy use for domestic space heating

The level of reported variability of domestic space heating energy use is extremely high, the coefficient of variation being 20% even for groups of similar houses. In consequence, there is a need for heating systems to work effectively and economically over a wide range of energy use levels and there is also a need for large sample sizes in evaluating field results if the effects of individual factors contributing to the overall variability are to be assessed. For dissimilar houses, samples of 25 or more are necessary for the detection of individual factors and hundreds may be required for their accurate estimation.The effect on energy use of night temperature set-back is shown theoretically to be equivalent to a 2$\text{1}\text{2}$% energy saving per degree Kelvin temperature depression. The effects of more intermittent heating system operation are provisionally estimated, a 50% energy saving being estimated for a 6-h period of daily use at the required temperature. Effects of choice of internal temperature and ventilation rate on energy use are assessed.The energy savings made by such personal control strategies can be nullified by equipment deficiencies. The magnitudes of the effects of three such deficiencies (pipe or duct losses, unresponsive emitter control and upstairs overheating in mild weather) are estimated as each adding around 20% to the heating energy use of a typical house.The combined effects of energy saving strategies and equipment deficiencies make possible annual energy use figures from half to one-and-a-half times the designed level. The implications of this variability for heating system design are discussed.     

Model projections and policy reviews for energy saving in China's service sector

Energy efficiency of buildings in the service sector is becoming increasingly important in China due to the structural shift of the economy from industry to services. This paper employs a bottom-up cohort model to simulate current energy saving policies and to make projections for future energy use and CO₂ emissions for the period 2000–2030 in the Chinese service sector. The analysis shows that energy demand in the service sector will approximately triple in 2030, far beyond the target of quadrupling GDP while only doubling energy use. However, it is feasible to achieve the target of emission reduction by 40% in 2020 even under the poor state of compliance rate of building standard. This paper also highlights four crucial aspects of designing optimal energy saving policies for China's service sector based on the model results.     

Promotion of renewable energy in Baltic States

Baltic States have quite limited own energy resources. In the accession agreement with EU Lithuania, Latvia and Estonia have verified their targets to increase the share of electricity produced from renewable energy sources (RES-E) by the year 2010. Lithuania has target to increase RES-E from 3.3 to 7%, Latvia—from 42.4 to 49.3% and Estonia—from 0.2 to 5.1%. Promotion of use of renewable energy sources are among the priorities of energy policy in Baltic States. More wide use of renewable energy can make a valuable contribution to diversification of energy supply and increase of reliability of energy supply and to meeting GHG emission reduction targets. The article presents a detailed overview of the present policies and measures implemented in Baltic States aiming to support the use of renewable energy sources. The article presents a review of the present renewable situation in Baltic States and analyses policies and measures in place aiming to enhance use of renewables. The review of possibilities to use EU structural funds for the implementation of renewable energy projects in Baltic States was performed in the paper.     

武汉市既有公共建筑节能改造技术评估

采用能源审计的方法,分析了武汉市政府办公楼和大型公共建筑的节能潜力、节能率与回收期。结果表明,能源行为管理,过渡季节的自然通风,提高用能系统的能效比,充分利用可再生能源和自然采光等是成熟、可靠的节能技术。提出了节能分析按等价热值或者能质系数计算;节能率、经济性以年为单位核算;以实测能耗评价节能建筑,避免采用多种节能技术的建筑实际上是非节能建筑的现象。     

Situation and measures of China’s CO<Subscript>2</Subscript> emission mitigation after the Paris Agreement

Global response to climate change has entered the phase of full implementation of the Paris Agreement. To control the global temperature rise below 2°C, all countries must make more efforts to reduce emission. China has combined its goal of emission reduction for combating climate change with its domestic sustainable development strategy to promote energy revolution and the transition of economic development to low-carbon patterns. Through reinforcing the commitment and action before 2020, the CO₂ intensity of GDP can decrease by more than 50% by 2020 compared with that of 2005, and the external commitment target of a 40%–45% decrease can be over fulfilled. Currently, under the new economic normal, China further strengthens the policy measure, vigorously saves energy, enhances energy use efficiency and the economic output benefit, and simultaneously develops new and renewable energy and accelerates energy structural decarbonization, so that the annual decrease rate of the CO₂ intensity of GDP keeps a high level of more than 4% and remains increasing. Thus, the decrease rate of the CO₂ intensity of GDP will exceed the GDP growth rate, and then CO₂ emission will peak around 2030. This will promote the fundamental turning of economic development mode, and lay a foundation for the establishment of a sustainable energy system with near-zero emissions and with new and renewable energy as the main body in the second half of this century. China implements the concept of green low-carbon development and accelerates the low carbon transition of energy and economy to achieve win-win results in economic growth and CO₂ emission mitigation, and these policies and actions will also provide experiences for many other developing countries. On the other hand, China will continue to play a positive and constructive leading role in the implementation of the Paris Agreement internationally, and promote the construction of new mechanisms of win-win cooperation, fairness and justice and common development for global climate governance. Moreover, China will make an effort to build a community of common destiny for mankind, promote pragmatic cooperation among countries, especially among developing countries, and take combating climate change as a new development opportunity for jointly moving toward climate-friendly low-carbon economic development path.     

南京纺织"十五"期间能源消费状况以及"十一五"节能对策

纺织行业是重点耗能行业。南京纺织在“十五”期间经济发展较快,但能源消耗增长率却低于经济增长率,节能降耗取得了一定成效。文章分析了纺织系统在“十五”期间经济规模、能源消耗、节能工作,对纺织在“十一五”期间如何进一步开展节能降耗、资源综合利用工作提出了对策。     

Energy and economic evaluation of cooling,heating, and power systems based on primary energy

Cooling, Heating, and Power (CHP) systems have the potential to make better use of fuels than other technologies because of their ability to increase the overall thermal energy efficiency. Feasibility of CHP systems is generally driven by economic savings. In addition, economic evaluation of CHP systems is based on site energy use and cost, which could lead to misleading conclusions about energy savings. Since energy savings from CHP systems only occurs in primary energy, the objective of this investigation is to demonstrate that feasibility of CHP systems should be performed based on primary energy savings followed by economic considerations. This paper also evaluates the effect of the power generation unit (PGU) efficiency over the primary energy reduction when a CHP system is utilized. The advantages of operating CHP systems under a primary energy operational strategy, such as the proposed Building Primary Energy Ratio (BPER) strategy, are also discussed. Results show that for some cases economic savings are attained without the corresponding primary energy savings. However, the use of the BPER operational strategy guarantees better energy performance regardless of economic savings. Regarding to the PGU efficiency, an increase of the efficiency reduces the primary energy use more than proportionally. For example, increasing the PGU efficiency from 0.25 to 0.35 (increase of 40%) can reduce the primary energy use from 5.4% to 16% (increase of 200%).     

Towards a contemporary approach for understanding consumer behaviour in the context of domestic energy use

Domestic sector energy use is increasing in the UK and currently accounts for 30% of total use. Policies of liberalised energy markets have allowed greater consumer choice but have not sought to reduce carbon emissions. Overall sales of energy efficiency products are rising, but UK housing stock standards are poor and do not facilitate improved efficiency and further, the sales of such products are influenced by their price, thus the higher capital costs of products such as boilers and solar systems make them initially unattractive to consumers. Previous market-based research into the adoption of energy efficiency products has often focused on single factors, for example demographics. This has limited the ability of policy makers to make informed decisions that address a broader range of factors, such as individuals’ cognitive abilities, values and attitudes, as well as external factors such as social networks, marketing, and products and services. This paper provides a wider critique of the theoretical base related to consumer behaviour, product attributes and socio-environmental theories that relate to energy use. The aim of the paper is to draw together theories relevant to energy use in order to aid policy making in the broader context and to develop the discussion around integrated theories of consumer behaviour.     

Making renewable energy competitive in India: Reducing financing costs via a government-sponsored hedging facility

In India, a significant barrier to market-competitiveness of renewable energy is a shortage of attractive debt. Domestic debt has high cost, short tenors, and variable interest rates, adding 30% to the cost of renewable energy compared to renewable energy projects elsewhere. Foreign debt is as expensive as domestic debt because it requires costly market-based currency hedging solutions. We investigate a government-sponsored foreign exchange facility as an alternative to reducing hedging costs. Using the geometric Brownian motion (GBM)² as a representative stochastic model of the INR–USD foreign exchange rate, we find that the expected cost of providing a currency hedge via this facility is 3.5 percentage points, 50% lower than market. This leads to an up to 9% reduction in the per unit cost of renewable energy. However, this requires the government to manage the risks related to unexpected currency movements appropriately. One option to manage these risks is via a capital buffer; for the facility to obtain India's sovereign rating, the capital buffer would need to be almost 30% of the underlying loan. Our findings have significant policy implications given that the Indian government can use this facility to make renewable energy more competitive and, therefore, hasten its deployment.