太阳能热泵-蓄热电锅炉弃风消纳策略仿真

随着清洁能源政策的不断完善,风能和太阳能资源得到了充分的利用,但是风电的“昼低夜高”反调峰特性会导致风电消纳能力受限。为了更大限度且更加灵活地消纳弃风电量,文章设计了以蓄热式电锅炉储热为主导,直接供电模式下的太阳能热泵-弃风蓄热供暖系统。同时,为兼顾系统运行成本和弃风消纳电量,建立了系统的优化调度数学模型,综合考虑弃风量、电锅炉功率、热功率及蓄热量等约束条件,采用NSGAII多目标优化算法对模型进行求解,从而获得蓄热电锅炉运行功率的优化调度方案。研究结果表明,优化调度方案可在保证系统经济运行下合理调度蓄热电锅炉的运行功率,与优化调度前相比,优化后的系统能够多消纳弃风电功率3 261 kW,弃风消纳率可达26%。     

基于负荷侧响应的含储热热电联产的风电消纳模型

为了有效减少弃风,提高风电消纳能力,该文从负荷侧出发,通过峰谷分时电价策略引导用户的用电方式,达到削峰填谷,优化负荷曲线的目的。同时,在传统热电联产机组中应用大容量储热装置,通过对储热环节的控制,解耦“以热定电”约束,提高系统调节能力。以系统煤耗量最低为目标,构建包含储热的热电联产机组与风电联合出力优化调度模型。该模型考虑系统中的含储热热电联产机组运行成本,同时兼顾储热、负荷侧响应与热电平衡的相关约束等因素,采用基于模拟退火的粒子群算法对模型进行求解,并利用算例比较不同模式下的结果,验证了模型的有效性。     

基于风电-蓄热式电锅炉联合供暖的风电消纳多目标双层优化调度

为解决中国"三北"地区供热期间"风热冲突"问题,在风电消纳困难的电网末端加装蓄热式电锅炉,利用弃风电量进行供热以促进风电就地消纳。该文以弃风消纳最大和运行成本最小为目标建立基于风电-蓄热式电锅炉联合供暖的风电消纳多目标优化模型,提出双层优化求解的思想,并采用改进型多目标粒子群优化算法进行求解,对生成的Pareto解集使用模糊隶属度法进行筛选。基于中国吉林省某示范工程的实际数据的仿真结果验证了该方法能够有效降低运行成本,提高风电消纳水平。     

基于热网储热特性的电-热系统联合经济调度

针对含高比例热电机组的电力系统如何提高调峰能力并减少弃风问题,以最小弃风电量为目标,提出一种基于热网储热特性的电-热系统联合调度策略,构建电-热系统联合经济调度模型。热网具有储热特性,通过对热网蓄放热进行有序地调控,在短时间内调整热电机组供热量改变机组发电水平,降低供热和发电的耦合程度,能够保证热需求的同时提高机组的调峰能力。采用改进的粒子群算法对所提模型进行求解,仿真结果表明所提策略可有效提高系统风电消纳水平,减少弃风量。     

基于热电联产运行模式的光热发电调峰策略

针对中国"三北"地区冬季供暖期因热电机组"以热定电"运行约束,导致系统调峰能力不足而造成的大量弃风问题提出一种基于热电联产运行模式的光热电站调峰策略。该文首先分析光热电站辅助供热后热电机组电热特性及其调峰能力变化情况,然后根据不同时段的负荷特性及热电机组运行状况制定出基于热电联产运行模式的光热电站在各时段的运行策略,在此基础上建立含光热电站、热电机组、纯凝机组、风电场的电力系统电热综合调峰优化模型。与传统模型相比,新模型增加了系统热平衡约束、热电机组的热电耦合约束、光热电站运行约束等。仿真结果表明基于热电联产运行模式的光热电站,通过辅助供热不但可有效提高电网的风电消纳水平,同时可避免运行成本较高的纯凝式机组频繁调节,提高系统运行的经济性。     

基于供热网络热惯性的风电消纳能力评估

在传统的热电联产调度中,电功率和热功率之间的平衡关系时刻受到限制,导致系统调峰能力下降、弃风率过高。基于此,考虑了区域供热网络（DHN）的实际物理模型,利用DHN的热惯性进行蓄热,用于提高热电联产（CHP）机组的运行灵活性。该文构建了供热网络的热惯性模型,并引入供、回水时滞性来描述热水在网络中的传输时延,以系统运行成本及弃风量最小为目标函数,考虑了系统常规约束和热力系统模型约束,建立了包含风电机组、火电机组、热电联产机组和热惯性的电-热综合系统优化模型。结果表明,所提模型不仅可以减小系统弃风率,还可以获得热源处优化后的供水和回水温度。     

配置蓄热装置对热电机组运行经济性的影响分析

为了解决我国“三北”地区的弃风、弃电问题,提升热电机组的调峰能力尤为重要,在热电机组中配置蓄热罐可实现“热电解耦”,是扩大机组调峰空间的有效方法。本文以某330 MW亚临界机组为研究对象,利用Aspen Plus软件构建了配置蓄热装置的热电机组仿真模型,借助煤耗量、能量效率等指标,分析了蓄热装置的抽汽位置对热电机组经济性的影响。模拟结果表明：热电机组在不同工况下模拟计算结果均与实际工程数据吻合良好,验证了计算模型的可靠性;在机组的采暖抽汽口抽汽进行蓄热,最为经济合理;针对选取的六种典型工况,配置蓄热装置后的机组相比原机组最高可节省总煤耗量7 003.74 kg,平均每小时可减少1 167.29 kg燃煤量。     

基于旁路系统提升热电机组风电消纳能力研究

针对中国三北地区冬季供热期弃风现象严重的问题,提出利用高低压旁路供热解耦传统热电机组的电热强耦合关系,并基于旁路系统供热的热电机组电热特性,建立风电消纳能力数学模型,根据电网调峰需求,给出热电机组的运行策略。结果表明:高低压旁路系统参与供热可大幅提升热电机组的风电消纳能力和供热能力。为了保证高低压旁路供热安全,要注意高低压旁路蒸汽流量的匹配关系。采用"传统抽汽+高低压旁路"切换方式供热,风电消纳能力最强。以某330 MW热电机组为例,采用高低压旁路供热可进一步提升供热能力90.56%;在满足额定供热量的前提下,采用"传统抽汽+高低压旁路"切换方式供热可进一步提升热电机组风电消纳能力324.46%。     

供热期调峰约束下电网弃风情况分析

在研究供热期电网弃风机理基础上,分析热电联产机组电热耦合关系,并建立考虑电力系统和热力系统约束的区域电网调度模型,定量分析风电渗透率、热负荷水平及电负荷水平对弃风影响。算例使用CPLEX优化软件求解,结果表明:供热期负荷低谷时段,热电联产机组调峰容量为额定容量的20%,严重挤压风电上网空间,导致大量弃风;热电联产机组热负荷水平由额定容量的68.3%下降到52.4%,可减少30%弃风。     

冬季风电消纳的两种途径的节能分析

冬季北方地区风电等清洁能源消纳矛盾突出,热电联产机组运行容量占比高、受热负荷的约束调峰能力差是造成弃风、弃光的主要原因。在解决弃风、弃光等问题上,针对北方冬季风电消纳的两种途径,依据热力发电厂热经济性评价方法,对不同形式的机组、采取不同深度调峰的改造技术路线,进行了节能分析。提出了在发电侧纯凝机组应首先进行深度调峰、热电联产机组采取增设蓄热罐改造进行深度调峰,为风电等清洁能源让出发电空间;在用电侧对供热锅炉实施电锅炉改造,消纳剩余的风电,实现经济效益和社会效益的最大化。     

余热回收用热管及热管式换热器的研究

简要介绍了热管及热管式换热器的工作原理,热管式换热器在工业余热回收中的应用,以及热管式换热器运行过程中防止积灰和低温腐蚀等问题的有效措施。     

On the steady‐state modelling of a two‐stage evaporator system

We develop and validate against experimental measurements a steady‐state two‐stage flooded refrigerant evaporator model for a heat pump drying system. A prototype two‐stage heat pump dryer test facility was designed, built and instrumented to provide the required measurements for the validation of the model. Repeatability and data quality tests were conducted to evaluate the accuracy of measurements. Experimental data could be reproduced to within ±6.5 per cent of replicated air and refrigerant side measurements for the same evaporator's air inlet conditions while the discrepancy of energy balance at the air‐side and refrigerant‐side was observed to be within ±8.9 per cent. The two‐stage evaporator model predicted the air‐side total heat and latent heat transfer of the two‐stage evaporator to within (?6.3 per cent, 7.6 per cent) and (?11.5 per cent, 9.5 per cent), respectively. On the refrigerant‐side, the model enabled the calculation of the degree of superheat to within (?10.6 per cent, 1.7 per cent). The model has shown that there is significant improvement in the heat recovered from a two‐stage evaporator system compared to a single evaporator system. In addition, the model demonstrated that the improvement in total heat recovery could be as high as 40 per cent over its base‐value when the latent to total load at the two‐stage evaporator is increased. Copyright © 2001 John Wiley & Sons, Ltd.     

显热储热材料的制备及性能研究

采用水泥作为材料的胶凝剂,添加热容、热导率大的物质作为骨料来制备混凝土储热材料。研究表明:当铝酸盐水泥含量为10%时,材料的抗压、抗折强度能满足工业需求;材料的比热容随温度的升高先增大,在500℃时达到最大,后随着温度的升高反而降低;材料的热导率随着石墨粉含量的增加几乎成直线上升,当石墨含量为5%时材料的热导率大于1.7W/(m·K)。     

间歇式热处理炉传热计算与分析

建立了台车式热处理炉炉膛传热数学模型和辐射换热器工作模型,分析了换热器的传热特性（空气预热温度、壁温、传热系数）随炉况的变化。结果表明,辐射换热器的传热特性随炉子的升温及保温过程变化而波动很大,因而对炉子的热工性能产生了影响。     

Quantification of the European industrial heat demand by branch and temperature level

We present the first comprehensive estimate of the final energy demand for heat in all EU28 member states for the reference year 2012, differentiated by temperature levels, comparing two different approaches. Two different calculation approaches based on different data sets yielded estimates of the total final energy demand for heat in the EU28 of 8150 PJ and 8518 PJ in 2012, respectively. Approach 1 distinguishes between three different process heat (PH) temperature levels and results in final energy demand for heat <100°C: 2077 PJ, 100–400°C: 2214 PJ and >400°C: 3859 PJ. The second approach distinguishes between low temperature space heat and hot water (<100°C: 1161 PJ) and four different PH temperature levels with a resulting energy demand of <100°C: 1027 PJ, 100–500°C: 1785 PJ, 500–1000°C: 1679 PJ and >1000°C: 2865 PJ. The high share of high‐temperature heat illustrates the limits to the potential decarbonisation of industrial thermal processes with renewable energy sources such as (non‐concentrating) solar thermal, geothermal or environmental heat. Therefore specific information on required temperature levels is of the essence. This, in turn, points out the relevance of renewable electricity and synthetic fuels based on renewable power for a significant reduction of CO₂ emissions from the industry sector in Europe. Considering current data quality, it is recommended to develop a consistent, comprehensive methodology to significantly improve the data basis on industrial heat demand. Copyright © 2015 John Wiley & Sons, Ltd.     

Heat pump dryer Part 1: Simulation of the models

Heat pump dryer is a complex system because of the interaction of heat and mass transfer of the working fluids. Since the system cannot be completely close, ambient conditions (temperature and humidity) influence the performance of the system. To investigate the performance of the heat pump dryer thoroughly, simulation models of heat pump dryer components have been developed. The finite-difference method was employed in the simulation to examine the state of the working fluids and heat and mass transfer. The simulation of each component can be used to construct different system configurations the results of which are reported in Part 2.     

国内分离式热管概况与热环研究的小结及展望

本文对我国分离式热管技术的研究进行了简要概况,针对工程中热源在上,冷源在下及冷热源相距较远时的热量传递问题,在分析了一般分离式热管及“水回路”等技术的基础上,对一种新型分离式热管－泵或风机驱动的动力型分离式热管（简称热环）的研究进行了小结和展望。     

Field test of a novel combined system of a high-efficiency heating/cooling heat pump and a clathrate cool storage unit

The Research Laboratory of Kyushu Electric Power Co., Inc. (KEPCO) installed a novel system in March 1992 which is a combination of a super heat pump with about twice the performance of a conventional one and a compact chemical storage-type clathrate cool storage unit. A field test was implemented by integrating these units into an actual air-conditioning system. As a result of the test, system performance was determined and the effectiveness of the system was confirmed. © 1998 Scripta Technica. Heat Trans Jpn Res, 26(6): 410–418, 1997     

Heat-spreading analysis of a heat sink base embedded with a heat pipe

A simplified model predicting the heat transfer performance of a heat sink base with a high thermal conductivity was developed. Numerical analysis was performed using the commercial software FLUENT. The investigation indicates that for heat sink bases with a high effective thermal conductivity, such as the base embedded with a typical heat pipe, the entire heat sink can be modeled as a flat plate with a uniform temperature and an effective convection heat transfer coefficient. This simplified model can be used to determine the heat transfer performance of a heat sink embedded with a typical heat pipe or vapor chamber.     

Augmentation of heat transfer through passive techniques

The thermal performance of energy preservation systems is greatly improved by increasing miniaturization and boosting. These are imaginative (or Promethean) techniques to enhance heat transfer. Enhancement methods of heat transfer draw great attention in front of the industrial sector because of their ability to provide energy savings and raise the economic efficiency of thermal systems. Three techniques these methods are categorized; those are active, passive, and compound. Different types of components are used in passive methods because of the transfer/working fluid flow path to the enhancement of the heat transfer rate. In this article, the subject of the review was the passive heat transfer enhancement methods including inserts (conical strips, winglets, twisted tapes, baffles), porous materials, coil/helical/spiral tubes, rough surfaces (corrugated/ribbed surfaces), extended surfaces (fins) and nanofluids (mono and hybrid nanofluid). Recent passive heat transfer enhancement techniques are studied in this article as they are cost-effective and reliable, and also comparably passive methods do not need any extra power to promote the energy conversion systems' thermal efficiency than active methods. In the passive approaches, various components are applied to the heat transfer/working fluid flow path to improve the heat transfer rate. The passive heat transfer enhancement methods studied in this article include inserts (twisted tapes, conical strips, baffles, winglets), extended surfaces (fins), porous materials, coil/helical/spiral tubes, rough surfaces (corrugated/ribbed surfaces), and nanofluids (mono and hybrid nanofluid). From the pioneers' research work, it is clear that a lower twist ratio and lower pitch, lesser winglet angles can provide more heat transfer rate and a little bit more friction factor. In the case of nanofluids, a little bit of pumping power is enhanced. Finally, heat transfer enhancement is compared with the thermal performance factor, which is more than unity.