Techno-economic analysis of a hybrid energy system for CCHP and hydrogen production based on solar energy

A typical problem in Northeast China is that a large amount of surplus electricity has arisen owing to the serious photovoltaic power curtailment phenomenon. To effectively utilize the excess photovoltaic power, a hybrid energy system is proposed that uses surplus electricity to produce hydrogen in this paper. It combines solar energy, hydrogen production system, and Combined Cooling Heating and Power (CCHP) system to realize cooling, heating, power, and hydrogen generation. The system supplies energy for three public buildings in Dalian City, Liaoning Province, China, and the system configuration with the lowest unit energy cost (0.0615$/kWh) was obtained via optimization. Two comparison strategies were used to evaluate the hybrid energy system in terms of unit energy cost, annual total cost, fossil energy consumption, and carbon dioxide emissions. Subsequently, the annual total energy supply, typical daily loads, and cost of the optimized system were analyzed. In conclusion, the system is feasible for small area public buildings, and provides a solution to solve the phenomenon of photovoltaic power curtailment.     

冷热电三联供系统的优化研究

冷热电联供系统主要应用于大型集中性供能系统中。作为分布式能源的一种,冷热电联供系统具有节约能源、改善环境、提高电力综合效益的优势。一般情况下,三联供系统是以天然气为燃料带动燃气轮机、微燃机或内燃机发电机等燃气发电设备运行,产生的电力供应用户的电力需求,系统发电后排出的余热通过余热回收利用设备(余热锅炉或者余热直燃机等)向用户供热、供冷。通过这种方式提高整个系统的一次能源利用率,实现能源的梯级利用,还可以提供并网电力作能源互补,经济收益和效率均得以提升。研究较为常见的燃气轮机中的一种蒸汽型吸收式冷热电联产系统,对不同配置方式和运行方式进行横向与纵向交叉比较,以完成系统优化研究。     

Thermodynamic performance study of a new SOFC–CCHP system with diesel reforming by CLHG to produce hydrogen as fuel

In this paper, a combined cooling, heating and power system based on diesel-fueled chemical looping hydrogen generation and solid oxide fuel cell, and with CO₂ capture was established. The system can achieve efficient power generation while separating CO₂ without energy consumption, and effectively avoid the carbon deposition problem. Aspen software is used to simulate the process of the system, and FORTRAN program is used to calculate, through the thermodynamic analysis model, the unique performance change law of the new system using diesel is obtained, and thermodynamic analysis is performed on the system at last. The results show that the power efficiency of the new system is 54.1%, while the exergy efficiency and fuel energy saving ratio can reach 53%. At the same time, the influence of fuel flow and fuel utilization factor on the system performance does not continue to increase or decrease, and the system performance parameters will have a peak value with the change of pressure. The results not only provide a theoretical basis for the future construction of new diesel-fueled energy supply system, but also provide a new idea for the optimization scheme of energy-saving system and carbon recovery.     

浅谈分布式区域冷热电联供系统

建筑节能已成为我国节能技术领域的重要议题。冷热电三联供技术是充分利用低品位热能的一种有效手段,该系统能源综合利用率高,一般均可达到70%以上。本文阐述了分布式区域冷热电联供系统的原理和特点,提出一种基于热气机的天然气能源岛系统。并指出充分推动分布式区域冷热电联供技术的应用,对于能源节约、环境保护、能源安全以及资本有效运作具有十分重要的意义。     

燃气内燃机发电机组在LNG接收站的应用

介绍了燃气内燃机发电机组的优点,结合工程实例,对燃气内燃机发电机组在 LNG接收站中应用的技术与经济性进行了探讨。     

基于质子交换膜燃料电池的冷热电联产系统研究进展

将质子交换膜燃料电池应用于冷热电联产系统中,可有效提高系统效率,实现冷热电供能的可持续发展。本文介绍了基于质子交换膜燃料电池的冷热电联产系统的数学建模、运行策略、能源管理、多维评价、系统优化理论与应用等方面的研究进展。根据现有研究,从能源禀赋、供需整合与多尺度建模、多能互补供能、系统评价体系、系统集成优化多方面指明未来该系统的研究可从多尺度建模、源网荷储深度融合、完善系统评价体系以及系统优化与实时调控等方面进行,为得到更为全面高效稳定的质子交换膜燃料电池冷热电联供系统提供新思路。     

含光伏蓄电池的冷热电联供系统运行模式评估

冷热电联供(CCHP)系统以其高效、清洁的特点而受到广泛的关注。将作为清洁能源和可再生资源的太阳能加入联供系统,可以进一步缓解能源危机和环境污染问题。为了提高分布式电源并网的稳定性,设计了一种可以平滑输出功率的光伏蓄电池系统,并将其与传统的CCHP系统相结合构建了一个综合型的联供系统。在热跟随(FTL)和电跟随(FEL)两种运行模式下,考虑电动汽车充电负荷的影响,评估环境成本和全寿命周期成本两个指标。     

含光伏和蓄能的冷热电联供系统调峰调蓄优化调度

冷热电联供(CCHP)系统的能源优化调度,可以有效提高终端用户的能源利用效率,缓解区域电网能源供需矛盾,促进分布式可再生能源的就地消纳,最大程度地实现区域电网的削峰填谷。建立了含光伏和蓄能的CCHP系统调峰调蓄优化调度数学模型,以最小化经济成本和电网供电方差为目标,引入权重系数,将多目标优化问题转化为单目标优化问题。针对光伏机组出力和负荷预测误差的随机性和不确定性,采用概率约束的形式表征其能量平衡方程。以天津中新生态城能源站CCHP系统为例进行算例分析,验证了所提模型的有效性和实用性。     

小型生物质沼气冷热电联供系统多目标优化设计与运行分析

数十千瓦级冷热电联供系统是解决中国农村生物质资源浪费的一种崭新而有效的途径,极具发展潜力。文中以动态系统仿真程序平台为基础,设计了一种计及设备变工况特性的小型生物质沼气内燃发电机组冷热电联供系统,并阐述了其能量流程和运行方式。同时,建立了综合能源、经济和环境效益的多目标优化模型,采用带约束因子的粒子群算法求解,实现了设备容量和运行参数优化。以某养殖场建筑全年冷热电负荷数据为例完成仿真,分析了优化系统运行情况,同时对比了沼气与天然气联供系统的性能差别。结果表明,优化后的联供系统较传统分供系统有效实现了节能减排,同时还可在寿命年限内回收投资成本;另一方面,相比天然气联供系统,沼气系统在节约能源成本和减排二氧化碳方面均具明显优势。     

Cross-regional integrated energy system scheduling optimization model considering conditional value at risk

Integrated energy system is a very important way to improve energy efficiency. Based on the combined heating cooling and power system, combined with energy storage equipment, a cross-regional integrated energy system scheduling optimization problem is studied. An integrated energy system scheduling optimization model is established that meets the requirements of electrical, heating, and cooling load under a variety of energy sources while both considering the interaction of electrical, heating, and cooling load between regions, and complementation of them within one region. Meanwhile, the value at risk (VaR) theory is introduced and the operating constraints of equipment in the integrated energy system fully considered, the integrated energy system scheduling model with VaR is established. The example shows that the model can realize multi-type electrical, heating, and cooling load optimized by schedule across regions under the premise of satisfying the balance of energy supply and demand, which can reduce the system operation cost. The sensitivity analysis of the minimum expected cost and the influencing factors of conditional VaR is carried out to verify the validity and feasibility of the proposed model.

• An integrated energy system scheduling optimization model is established that meets the requirements of electrical, heating, and cooling load under a variety of energy sources while both considering the interaction of electrical, heating, and cooling load between regions, and complementation of them within one region.
• By using the conditional value at risk theory to consider various types of the integrated energy system complements and evaluates the operational risk of the system under optimal operating conditions of the system.
• The total cost of system scheduling operation is proportional to the storage capacity, which is inversely proportional to the heat storage capacity and inversely proportional to the pipeline capacity within a certain interval.