Multiple-type solutions for multipole interface solitons in thermal nonlinear media

We address the existence of multipole interface solitons in one-dimensional thermal nonlinear media with a step in the linear refractive index at the sample center. It is found that there exist two types of solutions for tripole and quadrupole interface solitons. The two types of interface solitons have different profiles, beam widths, mass centers, and stability regions. For a given propagation constant, only one type of interface soliton is proved to be stable, while the other type can also survive over a long distance. In addition, three types of solutions for fifth-order interface solitons are found.Comment: 5 pages, 5 figure

Control strategies for variable speed pumps in super high-rise building

The article discusses the proposed alternative control strategy to test and simulate chilled water pumps energy in the building. The chilled water pipelines and terminal units are associated with condenser water pump and primary chilled water pump to transfer the cooling energy from low zones to high zones to avoid high water static pressure. Moreover, the original control strategy generates 12.02% to 16.01% of energy to heat exchangers and improve control strategy in practical applications. Two control strategies for variable speed pumps were tested in a super high-rise building in Hong Kong. (1) The 1,608 ft (490 m) high building has a floor area of 3.4 million [ft.sup.2] (321 000 [m.sup.2]). The basement is four floors, a block building is six floors and a tower building is 98 floors

Model-based optimization of ground source heat pump systems

This paper presents the development of an optimization strategy for ground source heat pump (GSHP) systems equipped with variable speed pumps in the ground loop system. The optimization problem is formulated using a model-based approach, in which the component models are used to estimate the system performance under various trial settings and an exhaustive search method is used to identify the optimal settings under the search ranges defined. The variable optimized is the outlet water temperature from the ground heat exchangers, which can be used as a set-point to control the operation of the variable speed pumps in the ground loop system. The overall objective of the optimization is to minimize the system power consumption while providing required building heating and cooling demand. The performance of the proposed strategy is tested and evaluated through simulations. It is shown that, compared to a two-stage control strategy for variable speed pumps, the proposed strategy can save 4.2% of cooling power consumption of the GSHP system studied. The methodology used in the development of this proposed strategy can be potentially useful for control optimization of any types of GSHP systems. For complex systems, a performance map can be generated based on this method and then used to practically control the operation of GSHP systems

Energy and exergy analysis of a desiccant cooling system integrated with thermal energy storage and photovoltaic/thermal-solar air collectors

This paper presents an energy and exergy analysis of a desiccant cooling system integrated with an air-based thermal energy storage (TES) unit using phase change materials (PCMs) and a photovoltaic/thermal-solar air collector (PV/T-SAC). The PV/T-SAC was used to generate thermal energy for desiccant wheel regeneration and space heating, and the TES was used to solve the mismatch between thermal energy supply and demand. The performance of this system was evaluated using a simulation system developed using TRNSYS. The effects of several key parameters on solar thermal contribution, specific net electricity generation, and the exergy destructions of individual components and overall system were investigated. It was found that the system exergy destruction was mainly resulted by the PV/T-SAC. Both the exergy performance and energy performance of this system were significantly influenced by the length and PV factor of the PV/T-SAC used. The results obtained from this study could be potentially used to guide the optimal design of desiccant cooling systems integrated with thermal energy storage and solar energy systems

Editorial to the Proceedings of the Improving Residential Energy Efficiency International Conference, IREE 2017

Editorial to proceedings of Improving Residential Energy Efficiency International Conference, IREE 2017, 16-17 February 2017, Wollongong, Australi