我国北方地区的热电联产机组(combined heat and power,CHP)装机容量较大,在供暖期受“以热定电”约束产生大量碳排放。在CHP机组中加入碳捕集设备(carbon capture and storage,CCS)能减少其碳排放,但加剧了CHP机组的电、热耦合,因此,...我国北方地区的热电联产机组(combined heat and power,CHP)装机容量较大,在供暖期受“以热定电”约束产生大量碳排放。在CHP机组中加入碳捕集设备(carbon capture and storage,CCS)能减少其碳排放,但加剧了CHP机组的电、热耦合,因此,该文引入电锅炉及储热装置,为CCS辅助供热,针对含电锅炉辅助供热的CHP-CCS机组的电热系统低碳调度开展研究。首先研究具有储热CHP-CCS机组的运行特性模型,然后建立考虑碳交易成本的含CHP-CCS机组的电热系统低碳调度模型,其中采用模糊机会约束描述风电及负荷的不确定性。最后以改进的IEEE 30节点系统和西北地区某实际系统为算例,分析不同热源容量及置信水平对电热系统运行经济性、碳排放及弃风的作用,给出了电热系统日优化调度方案。展开更多
High-temperature corrosion is a serious problem for the water-wall tubes of boilers used in thermal power plants. Oxidation, sulfidation and molten salt corrosion are main corrosion ways.Thereinto, the most severe cor...High-temperature corrosion is a serious problem for the water-wall tubes of boilers used in thermal power plants. Oxidation, sulfidation and molten salt corrosion are main corrosion ways.Thereinto, the most severe corrosion occurs in molten salt corrosion environment. Materials rich in oxides formers, such as chromium and aluminum, are needed to resist corrosion in high-temperature and corrosive environment, but processability of such bulk alloys is very limited. High velocity electric arc spraying (HVAS) technology is adopted to produce coatings with high corrosion resistance. By comparison, NiCr (Ni-45Cr-4Ti) is recommended as a promising alloy coating for the water-wall tubes, which can even resist molten salt corrosion attack. In the study of corrosion mechanism, the modern material analysis methods, such as scanning electron microscopy (SEM), X-ray diffractometry (XRD) and energy dispersive spectrometry (EDS), are used. It is found that the corrosion resistances of NiCr and FeCrAI coatings are much better than that of 20g steel, that the NiCr coatings have the best anti-corrosion properties, and that the NiCr coatings have slightly lower pores than FeCrAI coatings.It is testified that corrosion resistance of coatings is mainly determined by chromium content, and the microstructure of a coating is as important as the chemical composition of the material. In addition, the fracture mechanisms of coatings in the cycle of heating and cooling are put forward. The difference of the thermal physical properties between coatings and base metals results in the thermal stress inside the coatings. Consequently, the coatings spall from the base metal.展开更多
The aim of this paper is to present the concept of a simple and cheap upgrade for electric water boilers, allowing them to provide power quality services to the distribution grid. The upgrade requires only minimum add...The aim of this paper is to present the concept of a simple and cheap upgrade for electric water boilers, allowing them to provide power quality services to the distribution grid. The upgrade requires only minimum additional hardware and it is easily installable. “Smart Boilers”, as the upgraded boilers are named, perform precise active and reactive power control, but most significantly mitigate line current harmonics. Αctive and reactive power control is implemented by appropriate regulation of the modulation sinewave amplitude and phase, respectively. This type of control is easily customizable in order to accommodate a variety of power quality targets, depending on the required level of services and available grid monitoring equipment. The method used for line current harmonic compensation is based on the injection of mirror harmonics created at the modulation stage of the converter. It is indifferent of harmonic source: it is equally successful at mitigating harmonics caused by the power electronic converter of the Smart Boiler, other sources of current harmonics or loads. The achieved grid services are clearly beyond the “on/off” operation of electric boilers, currently implemented by Demand Side Management (DSM) in order to shift load away from peak hours. It has been demonstrated through simulations, that Smart Boilers can assist voltage regulation at terminal buses, compensate reactive power and suppress harmonic currents at lines.展开更多
文摘我国北方地区的热电联产机组(combined heat and power,CHP)装机容量较大,在供暖期受“以热定电”约束产生大量碳排放。在CHP机组中加入碳捕集设备(carbon capture and storage,CCS)能减少其碳排放,但加剧了CHP机组的电、热耦合,因此,该文引入电锅炉及储热装置,为CCS辅助供热,针对含电锅炉辅助供热的CHP-CCS机组的电热系统低碳调度开展研究。首先研究具有储热CHP-CCS机组的运行特性模型,然后建立考虑碳交易成本的含CHP-CCS机组的电热系统低碳调度模型,其中采用模糊机会约束描述风电及负荷的不确定性。最后以改进的IEEE 30节点系统和西北地区某实际系统为算例,分析不同热源容量及置信水平对电热系统运行经济性、碳排放及弃风的作用,给出了电热系统日优化调度方案。
文摘High-temperature corrosion is a serious problem for the water-wall tubes of boilers used in thermal power plants. Oxidation, sulfidation and molten salt corrosion are main corrosion ways.Thereinto, the most severe corrosion occurs in molten salt corrosion environment. Materials rich in oxides formers, such as chromium and aluminum, are needed to resist corrosion in high-temperature and corrosive environment, but processability of such bulk alloys is very limited. High velocity electric arc spraying (HVAS) technology is adopted to produce coatings with high corrosion resistance. By comparison, NiCr (Ni-45Cr-4Ti) is recommended as a promising alloy coating for the water-wall tubes, which can even resist molten salt corrosion attack. In the study of corrosion mechanism, the modern material analysis methods, such as scanning electron microscopy (SEM), X-ray diffractometry (XRD) and energy dispersive spectrometry (EDS), are used. It is found that the corrosion resistances of NiCr and FeCrAI coatings are much better than that of 20g steel, that the NiCr coatings have the best anti-corrosion properties, and that the NiCr coatings have slightly lower pores than FeCrAI coatings.It is testified that corrosion resistance of coatings is mainly determined by chromium content, and the microstructure of a coating is as important as the chemical composition of the material. In addition, the fracture mechanisms of coatings in the cycle of heating and cooling are put forward. The difference of the thermal physical properties between coatings and base metals results in the thermal stress inside the coatings. Consequently, the coatings spall from the base metal.
文摘The aim of this paper is to present the concept of a simple and cheap upgrade for electric water boilers, allowing them to provide power quality services to the distribution grid. The upgrade requires only minimum additional hardware and it is easily installable. “Smart Boilers”, as the upgraded boilers are named, perform precise active and reactive power control, but most significantly mitigate line current harmonics. Αctive and reactive power control is implemented by appropriate regulation of the modulation sinewave amplitude and phase, respectively. This type of control is easily customizable in order to accommodate a variety of power quality targets, depending on the required level of services and available grid monitoring equipment. The method used for line current harmonic compensation is based on the injection of mirror harmonics created at the modulation stage of the converter. It is indifferent of harmonic source: it is equally successful at mitigating harmonics caused by the power electronic converter of the Smart Boiler, other sources of current harmonics or loads. The achieved grid services are clearly beyond the “on/off” operation of electric boilers, currently implemented by Demand Side Management (DSM) in order to shift load away from peak hours. It has been demonstrated through simulations, that Smart Boilers can assist voltage regulation at terminal buses, compensate reactive power and suppress harmonic currents at lines.
