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Vacuum interrupter is widely used in the medium-voltage power system. Controlling the arc by the magnetic field is an effective method to improve the breaking capacity. The transverse magnetic field (TMF) forces the constricted arc to rotate to reduce local overheating. In this paper, three kinds of TMF contacts, which are Swastika-type contact, cup-shaped contact, and double-TMF contact that combines Swastika-type and cup-shaped contacts coaxially, are investigated in a demountable vacuum chamber with a high-speed camera. The arc voltage and current are also recorded. The experiments were conducted with circuit currents from 5 to 20 kA (root mean square) with a frequency of 50 Hz. There are four current levels in the experiment, which are 5, 10, 15, and 20 kA, and at least three tests are taken for each current level. The results showed that under low current (I = 10 kA), the arc of the three TMF contacts did not rotate. Under high current (I = 20 kA), it was observed that the arc of Swastika-type and double-TMF contacts rotated in the gap. The arc speed of double-TMF contacts is higher than that of Swastika-type contacts. The cup-shaped contacts have the highest arc voltage and noise among the three TMF contacts. The Swastika-type contacts were eroded most seriously. The simulation results show the force distribution of the arc on different locations. The resultant force makes the arc rotate counterclockwise.

Architectural integration is a crucial issue in the development and spreading of solar collectors, especially in China, where several traditional buildings have pitch roof with tiles. In this paper, a novel roof solar collector (Type 1) providing hot water and space heating is designed to enable effective collection of solar heat as well integrating naturally. A dynamic numerical model is developed and validated with experimental data. The simulation of the Type 1 collector demonstrates its good characteristics regarding to the thermal insulation and transmission of solar radiation. A linear correlation between the instantaneous efficiency and the reduced temperature is established. Simulated results of the Type 1 collector are further compared with the other two types of roof solar collectors (i.e., Type 2 and Type 3). The comparisons indicated that the similar maximum instantaneous efficiency are achieved. However, the Type 1 collector is preferred as its heat loss coefficient is 54.4% lower compared to the Type 2 collector, and is 65.8% lower compared to the Type 3 collector. The afore-mentioned results confirm that the Type 1 collector introduced has potential to address the issue on the poor architectural quality of roof integrated solar collectors for Chinese traditional buildings.

A novel PV blind-integrated Trombe wall module (PVBTW) was first designed and constructed in the present study. A series of experiments were carried out to measure and analyze the impact of different inlet air flow rates and PV blind angles on electricity generation and heat gains of the PVBTW module. The results showed that the inlet air flow rate of 0.45 m/s and the angle of 50° were considered to be preferable for the PVBTW module. In order to determine the behavior of the designed PVBTW module, comparative experiments between the PVBTW module and the existing two types of PV-Trombe wall modules, namely PV cells fixed on the exterior glazing (PVGTW) and PV cells attached to massive wall (PVMTW) were then conducted under the real conditions. Through comparative experiments, it was found that electricity generation of the PVGTW module was highest, and those of the PVMTW and PVBTW modules were similar, whereas regarding to the heat gains, the ascending order became PVGTW, PVMTW and PVBTW. Combining heat gains and electricity generation, the PVBTW module was superior by 14.5% compared to the PVGTW and by 14.1% compared to the PVMTW with respect to the total efficiency.

The high-voltage dis-connector, as a key substation equipment in the power grid structure, is vitally important to the quality of the power grid operation. Due to the geographic location of Guangdong Province of China, many strong typhoons have caused great damage to power facilities in recent years. And the loss of the dis-connector is the most serious, which severely affects the reliability of the power supply. However, the research on the wind resistance of the dis-connector is still few, so the improvement work of the device is quite difficult. The phenomenon of strong typhoon destroying the dis-connector mainly includes the fracture of post insulator and the conductive arm. In the study of the mechanical properties of post insulator and the conductive arm, almost all wind loads are treated as a concentrated force, but the surfaces of the post insulator and the conductive arm are actually subjected to a continuous wind pressure distribution. The magnitude of the wind load and the error of its application method will inevitably lead to inaccurate stress and strain data obtained in the calculation of the strength of the post insulator and the conductive arm, so that the post insulator and the conductive arm cannot be accurately designed. In this paper, the wind resistance of the dis-connector are studied by using the fluid-structural coupling analysis method. Firstly, the hydrodynamic RNG k-e turbulence model is used to simulate the wind field around the dis-connector, so as to obtain the accurate result of the wind pressure distribution on the surface of the dis-connector. Then the surface pressure of the dis-connector calculated by hydrodynamics simulation is introduced into the structural module of Ansys software as the applied load. The finite element method is used to simulate and calculate the stress and strain of the dis-connector, so as to obtain the mechanical characteristics of the dis-connector under strong wind. In addition, this paper analyzes the effects of different wind speeds and different wind directions on the wind load applied to the surface of dis-connector, and provide a basis for wind resistance design of dis-connector.

Electrocardiogram (ECG)signals are important sign signal of human heart health. Arrhythmia is one of the main features of heart disease. Therefore, ECG signal recognition and classification have important clinical significance. In this paper, the ECG signals in the MIT - BIH standard library were used as sample data, which were identified and classified based on the algorithm of convolutional recurrent neural network (CRNN)in order to realize the intelligent identification and classification of ECG signals. The R-wave peak location and heartbeat segmentation of the ECG signals were performed on the sample data using the differential threshold method, and a convolutional recurrent neural network was constructed to identify and classify the signals. The classification results show that the overall recognition rate of ECG signals in the MIT - BIH database sample is 98.81 %, the recognition rate of normal ECG signals is up to 99.67%. The results show that the CRNN has strong generalization ability, fast convergence rate and a good recognition classification rate for ECG signals.

Research on PV/T (photovoltaic/thermal) solar collectors has been conducted for years because the collector can provide electric power and thermal energy simultaneously. A tri-functional PV/T collector is presented and studied in this paper. The collector can work in PV/water-heating mode or PV/air-heating mode for different energy demands. For two working modes, steady-state model and dynamic model of the collector are developed and validated with experimental results. Based on the validated models, the performance of collector is investigated under different flow rates, wind speeds, inlet air temperatures, and initial water temperatures. For PV/air-heating mode, the effects of wind speed and flow rate are investigated. A flow rate of 0.02 kg/(m2·s) is recommenced to balance the temperature increase and thermal efficiency. For PV/water-heating mode, the decrease of thermal efficiency with wind speed increase is observed but it slows down when wind speed is over 5 m/s. The curve of daily thermal efficiency is plotted with different initial water temperature in tank. With annual analysis under different climates, the tri-functional PV/T collector is proved to have better annual performance than separated PV/T water collector and PV/T air collector which could be left unused in some seasons.

Based on the operation of a Ground Source Heat Pump (GSHP) in Hefei, the heat exchange of the 100m depth vertical u-shaped pipe buried in the ground was analyzed, and the heat transfer performance, efficiency of the system and temperature variation of the ground were studied experimentally under the typical climate in Hefei. Temperature changes of the field near the heat exchanger after 8h and 24h were analyzed by numerical simulation. Results show that the system has a good performance in winter.

A fuzzy-Hammerstein model predictive control method is proposed for a continuous stirred-tank reactor (CSTR). In this paper T-S fuzzy model is used to approximate the static nonlinear characteristics of Hammerstein model, and a linear autoregressive model is used to solve the results of optimal control. The designed nonlinear predictive controller using Hammerstein model make good use of the ability of universal approach nonlinear of T-S model, and divide the question of nonlinear predictive control into the nonlinear model recongnization and the question of linear predictive control. The application results of CSTR process show the proposed control method has good control performance compared to PID controller.

A design of solar collector that is able to provide both hot water and hot air has been proposed to increase annual thermal conversion ratio of solar energy. By modifying the conventional flat-plate solar water heater, the collector with L-shape fins can also function as a double-flow solar air heater. Experiments have been conducted to investigate the dual functions of the collector. It is shown that the thermal efficiency of the collector reached 50% in water heating, and varied from 41% to 55% in air heating depending on the ambient condition and flow rate. Mathematical model has been presented for the collector working in air heating mode. The theoretical results are in good agreement with the experiment results. Theoretical results show that the air flow rate is a dominant factor to determine the efficiency. The enhancement of the L-shape fins on the performance of the collector in air heating is also proved from the theoretic results.

TOSA method is a new technique for faster time to improved SA. TOSA method traces optimal elements for reduce ineffective select in the simulated Annealing process. But TOSA take the uneven results in quality. In this paper, we propose a new technique that traces optimal solution in the SA process for high quality. We applied the method to the simple global placement problems, and found that it achieved more than 17 % better solution as the best case than TOSA.