This paper studies the event-triggered $H_{\mathrm{\infty }}$ control problem for networked switched systems with a mixed time and state-dependent switching law. By the event-triggering strategies, only necessary samplings of feedback signals are determined to be released. The advantages are that redundant transmissions and updates can be reduced. By the adopted switching law, each sub-system will work for a minimum dwell time, and then a state-dependent switching starts to work. Specifically, by using discrete event-triggering strategies and considering the effects of transmission delays, a time-delay closed-loop switched system is first established. Then, by utilising multiple Lyapunov functions method, sufficient conditions are presented to ensure the stability of the closed-loop switched system with a certain $H_{\mathrm{\infty }}$ performance level. In particular, since the switching instants and the event-triggered instants may be coupled, typical cases are discussed in detail. Moreover, the co-design conditions for state-feedback sub-controller gains and event-triggering parameters are developed. Finally, the effectiveness of the proposed method is verified by numerical simulations.

The microchannel flow boiling cooling technology has great potential for application in electronic devices under high heat flux conditions. Saturated flow boiling in microchannels with V-shaped grooved pin fins were simulated using the volume of fluid (VOF) model. The working coolant is Novec649. The depth-to-width ratio β of a single groove is set as 0, 1, and 2, respectively. The results show that with the increase of β, the maximal average temperature of heated walls decrease, and at q = 100, 300, and 500 kW·m^-2 the average temperature at β = 2 declined 1.49, 5.29K, and 9.31 K, respectively, compared with that at β = 0. The corresponding pressure drops are respectively decreased by 23.90%, 24.82%, and 23.98%. The corresponding heat transfer factor remarkably increases 13.97%-40.24%. Moreover, the model with β = 1 has the superior heat transfer coefficient while the model with β = 2 has the best comprehensive heat transfer as a whole.

Steam cooler is one of the most important mechanical equipment in thermal power generation system and nuclear power generation system. The steam cooler bears a huge temperature gradient load when the working conditions are switched. In order to analyze the thermal stress of steam cooler tube sheet with high temperature load under harsh working conditions, the thermal-structural coupling analysis model of steam cooler tube sheet is constructed with finite element method. The results show that the stress concentration exists at the position connection between heat exchanger tube and cylinder. The maximum stress is located at the outermost heat exchanger tube with the peak stress of 320MPa. The heat exchanger tube layout alone cause higher stress. This situation should be avoided in the design of heat exchanger tube sheet. Furthermore, the strength and safety of the steam cooler tube sheet are evaluated with the stress linearization method. The steam cooler tube sheet design meets the safety requirements of structural strength under high temperature load.

Reliability is the most important factor in instrumentation and control (I&C) system for nuclear power plant (NPP). Now in order to reach high reliability, static redundant and dynamic redundant technique is in common use. Static redundant method can keep out the failure of one module, but could not detect the mistake. Dynamic redundant mean would examine the mistake of the working unit, but can not ward off the failure. In this study, our main purpose is to develop the advanced redundant way which includes the advantage of static redundancy and dynamic redundancy means by mixed redundant model (MRM). Utilizing logic order in the relationship between unit and system using reliable diagram, analyzing the reliability of MRM by the way of probability, the result has obvious effect upon improving the system reliability compared with above two models. MRM can be applied for safety critical I&C.