Applied Mechanics and Materials Vols. 672-674

Abstract: With To obtain implications for supply of high efficiency home appliance, this study focused on boilers in the household sector to analyze efficiency grade, replacement cycle and usage condition of boilers and to examine possibility for introduction of high efficiency boiler and energy conservation.As a result, about 40% of households had grade 1 boiler, about 54% of households had grade 4 boiler, and remaining 6% had other grades. This did not differ much from the product ratio for each efficiency registered on [Efficiency Comparison], an energy efficiency management system. Increasing ratio of consumers are expected to purchase high efficiency boiler as development and supply of high efficiency products are institutionally reinforced.Also, general replacement cycle of boilers was investigated as 9 years based on living conditions, environment and marketing survey on the market. Energy conservation from sequential replacement of boilers other than grade 1 into grade 1 boilers during this life cycle of 9 years was calculated to be 6%.

Abstract: This paper presents a mixed-integer linear formulation for the thermal unit commitment problem considering the start-up and shut-down power trajectories. A realistic and accurate modeling of the unit’s operating phase is given, which includes the phases of start-up, dispatchable and shut-down. The start-up type is decided by the unit’s prior off-line time. The start-up costs and power trajectories depend on the type of start-up. A new set of binary variables is introduced to represent the dispatchable status, which can decrease the binary variables and constraints significantly. Finally, a test case study is analyzed to verify the correctness and show the computational performance of the proposed formulation.

Abstract: Campus energy consumption takes up a large proportion of the total expenses of the campus. At the same time power consumption is emphasis. In the paper design of campus energy monitoring system and key technologies are demonstrated. The above-mentioned scheme is applied in a university in the north of China. The energy-saving measures are studied combined with the characteristics of the specific energy consumption.

Abstract: The active distribution network is an effective approach to solve the problem such as the high penetration of intermittent renewable energy. This paper constructs single and hybrid energy storage battery systems in the active distribution network, calculates the economic benefits of the single and hybrid energy storage systems from six aspects in annual electricity sale revenue, ancillary revenue, investment cost, maintenance cost, landed cost and power shortage punishment cost. Take the lithium iron phosphate battery as single system, the lithium iron phosphate battery and Lithium titanate battery as the hybrid system to compute the cost benefit. The results show that the storage systems have effects to the intermittent renewable energy in peak shaving. Since the hybrid energy storage system can obtain more annual ancillary revenue, and the batteries’ work life is longer, it has more advantage in economic benefits than the single energy storage system.

Abstract: The flywheel energy storage technology is a new type of conversion and storage for electric energy, and it is also a research hotspot of energy field in the world. There are a large number of studies on dynamic characteristics of energy storage flywheel in recent years. The flexible support with a single point has small load-carrying ability but very low friction loss, which is appropriate to be used in small flywheel system. By using a small stiffness pivot-jewel bearing and an oil damper as the lower support of the flywheel, a high-speed flywheel shafting with a single point flexible support was built. The dynamic model of the shafting was obtained by means of the Lagrangian equation. Based on the same energy dissipation of oil damper and flywheel, the optimal equivalent damping of flywheel was determined. The optimization criteria for dynamic state and parameters between oil damper and shafting were also presented. The lower damper’s effects on the mode shapes, modal damping ratios and forced vibration were discussed.

Abstract: In this paper, the Unicom's medium-sized IDC room in a city of northern China is the research object for the study. Based on field research of the room refrigeration conditions, data center room air conditioning system is carried out to optimize and for energy conservation research. Through the analytic methods of energy saving-technology, the best energy saving solutions is explored.

Abstract: For the problems that operation energy consumption is large, lack of energy saving strategy existed in the speed skating ice rink in Harbin Ice Training Base, field investigation is conducted and the data measured schemes are put forward including the temperature distribution above ice surface in vertical direction, the indoor relative humidity, the refrigeration units power consumption, the inlet and outlet temperature of cooling water etc. Then select the data of general training days and typical match days for comparative analysis. The results show that the running cost of refrigeration units represents a significant proportion of the total running cost; lack of low energy consumption dehumidification method to solve the problem that fog above the ice surface; in winter, using the outdoor cold source can reduce energy consumption of the cooling tower. Based on them, energy saving operation strategy based on outdoor cold source and using the return secondary refrigerant from the ice rink for cooling dehumidification are put forward.

Abstract: An evaluating method for lifetime degradation degree of battery energy storage system (BESS) is proposed in this paper. Base on the method, relationships among capacity and degradation degree of lifetime of BESS, unmet reference power are analyzed. An evaluation index is then proposed considering operation cost of energy storage and penalty cost for failing to meet the reference power. Lastly, an optimal method for capacity configuration is developed and is verified in the study case.

Abstract: In this paper, ternary composite paraffin was used as raw material, vitrified microsphere and expanded pearlite were used as carrier, styrene-acrylic emulsion and EVA emulsion as encapsulated to prepare phase change energy storage mortar. According to paraffin adsorption capacity, leakage and other performance tests , the appropriate carrier and encapsulate materials were selected . The results show that, through both temperature-time curve test and DSC analysis, the best ratio of 3# paraffin to n-tetradecane to solid paraffin is 1:2:7. Vitrified microsphere as carrier, the amount of paraffin under vacuum adsorption condition for 30mins is 502.2% which is much higher than that of expanded pearlite. Styrene-acrylic emulsion as encapsulate material, the leakage of paraffin problem can be solved effectively, and in this case, the minimum leakage of paraffin/vitrified microsphere is only 4.42%. The compressive strength of paraffin/vitrified microsphere phase change energy storage mortar is 5.35 MPa, the thermal conductivity is 0.3372 W/m·K which improved the insulation performance of mortar significantly.

Abstract: By combining the climate conditions of hot-summer and cold-winter zone, this paper has analyzed the characteristics for energy saving of windows and doors, and the approaches for energy-saving design are proposed in accordance with the functions of thermal insulation in summer, heat preservation in winter and lighting. Through the material of glass and window frame, it can provide reference to material selection for doors and windows, and various door & window energy-saving technologies are proposed, such as the structure and measures which can improve the thermal performance of window and the reasonable area ratio of window to wall.