Advanced Materials Research Vols. 860-863

Abstract: The inconsistency of power battery pack is one of the key factors decreasing the battery performance. The common equalization techniques have some problems like control is complex; the equalization effect is not obvious and low efficiency. In this paper, an equalization charge apparatus was designed based on DC-DC partial voltage technique with the multiple secondary invert circuit and DSP technique and analyzed the main characteristics of this method. Its input is the energy of the whole battery pack. At last, an equilibrium charging experiment was done adopting a lithium-ion power battery pack constituted by 84 series 80Ah cells. The results show that the method can effectively improve the consistency of the battery, give full play to the performance of power battery and good equilibrium effect.

Abstract: The three-level converter based on A-NPC topology can improve waveform quality of the output voltage, decrease the switch voltage and reduce the loss of the inductor, thus it has broad application prospects in the electrical power storage domain. This paper built the semi-physical real-time simulation platform of A-NPC three-level battery power storage system by designing the control system and the main circuit of the A-NPC topology converter, and researched the control mechanism of the power storage converter control algorithm with digital simulation platform. The experimental results of the prototype machine show that the A-NPC three-level battery power storage system built in this paper was fine, compared with the most common two-level topology, three-level converter has characteristics of lower output current waveform distortion factor, lower current harmonics and higher efficiency. Three-level converter used in the power storage system is able to gain access to low THD during steady-state operation and fine dynamic characteristics.

Abstract: Hybrid energy storage system (HESS) including battery and super-capacitor can take advantages of both high energy density and high power density. In the stand-alone PV micro-grid, in which two buck/boost bidirectional converters are connected to the DC bus directly, a novel energy management scheme is proposed. After filtering the fluctuating power of the HESS, charge and discharge currents of the battery are controlled by hysteresis control method, the super-capacitor supplies the difference of the power. To leveling off the fluctuating power output of photovoltaic system and control the voltage of the DC bus, a new control strategy applied to the bidirectional converter of the super capacitor is put forward. The feed-forward loops of input voltage, load current and output voltage are introduced to improve the response speed and stability of the system. Results of the simulation show the effectiveness of the proposed energy management and control strategy.

Abstract: This article is based on the research of natural ventilation and indoor thermal environment. By selecting Xuzhou Long-distance Passenger South Station as a typical large space building and simulating the ventilation of the building, the article proposes the optimization strategies of Form, Space and Material and validates these strategies, to provide the energy-saving strategies for the design of Long-distance Passenger Station and large space architecture.

Abstract: As a new sustainable development technology, the greenhouse earth to air heat exchanger (EAHE) is more economic and energy-saving than other traditional thermal technologies for greenhouse because of the high heat capacity of the shallow soil. The research progress related to the greenhouse EAHE in China and around the world are viewed and discussed from two main aspects, in which some disadvantages are shown and the future study to be perfected is proposed as well.

Abstract: Due to the floor-radiation heating is widely applied in the northern city,export of various adjustment formula of floor heating and relatively more efficient way of adjustment is urgently needed.Various regulating mode of regulating formula derived by using heat balance equation,to calculate the water pump electricity consumption,and export of standard coal consumption and the emission of pollutants from coal combustion.Through the analysis that changing the flow mass at three stages with the mix water connection of the energy-saving effect is remarkable.

Abstract: A 1000MW ultra-supercritical unit was studied to gain the energy consumption characteristics by means of thermodynamic analysis. Comparing with the designed conditions, the power generation efficiency under real operation is much less; especially under 50% and 100% rated loads. The higher superheated steam temperature and lower reheat temperature were found to explain that. At the real running, the higher superheated steam temperature induced more attemperation water, while reheat temperature lower than the designed point would decrease the power output. Aiming at solving issues about temperature control in unit operation, several details could be paid extra attention to. For instance, attemperating water comes from outlet of the high-pressure heaters would have a much slighter influence on generating efficiency.

Abstract: Nowdays more and more methods for design and transformation Distributed Energy System are applied. Traditional optimization is based on the original system , by successively optimize the process in order to recovery heat as much as possible or to reduce the enery consumption . Pinch analysis can get the energy goal and expect heat exchangers number directly,according to the analysis of the users demand streams parameters cascade. In this paper, pinch analysis is applyed for the downstream heat exchanger network optimal design of the distributed energy system , and has proved that pinch analysis advantages for the distributed energy system integration.

Abstract: Power generation using waste heat from cement kiln can not only bring economic benefits to the enterprise, but also play an important role in environment protection. Constantly researches have proved that there is still large energy saving potential in its operation. In this paper, the waste heat power generation system was divided into several subsystems, and the exergy calculation model of each subsystem unit was established. Finally, the weakest part in energy use was found according to the results. It provides a scientific basis for performance improvement and energy saving transformation of waste heat power generation.

Abstract: The paper presents heat transfer enhancement by inserting a cylinder as spoiler element. It has a great significance for engineering. But its mechanism is still not very clear. Aiming at this problem, numerical simulation and experimental study on heat transfer enhancement by single cylinder or multi-row cylinders are summarized in this research. And they are also compared with other shape components. According to the results, the developing trend of heat transfer enhancement by cylinders is pointed out.