High voltage circuit breakers are the most important protection and control apparatus in power system. As a core part of circuit breakers, the operating mechanisms have a trend to be hydraulic-style in high voltage po...High voltage circuit breakers are the most important protection and control apparatus in power system. As a core part of circuit breakers, the operating mechanisms have a trend to be hydraulic-style in high voltage power grid. Compared with other hydranlic systems, the hydraulic operating mechanisms have the characteristics of high hydraulic pressure, high speed, high power and long-term waiting etc., and it is because of the characteristics that the hydraulic operating mechanisms become dif- ficult to be developed and have been arousing significant study interest from more and more researchers as well as their promising applications. Therefore, it is significant to summarize the hydraulic operating mechanisms on their development, characteristics, and key technologies etc. In this review, the evolution process and recent studies of hydraulic operating mechanisms at home and abroad are viewed. The review then focuses on the characteristics and key technologies of hydraulic operating mechanisms, especially on time and velocity characteristics, high-speed cylinder cushioning, fast response and great flow rate control valve, temperature compensation, system monitoring and fault diagnosis, intelligent operation, energy storage module, etc. In the end, the future trends of this field are presented.展开更多
The article analyses the problem of determining the operating parameters of the district heating substation cooperating with the air heating system in technological air conditioning systems equipped with heat exchange...The article analyses the problem of determining the operating parameters of the district heating substation cooperating with the air heating system in technological air conditioning systems equipped with heat exchangers with high efficiency of heat recovery.Attention was paid to the correct selection of heat exchangers for the heat output balance depending on the heat recovery protection algorithms against a drop in the temperature of the heat transfer surface below 0℃.Critical parameters were determined in Polish climatic conditions,at which the operation of the heat recovery exchanger in the air conditioning system is switched off or limited.It has been proven that the proper functioning of the district heating substation cooperating with the installation of air conditioning with high heat recovery efficiency requires the use of two heat exchangers with different characteristics,equipped with properly selected temperature control systems.The optimal model of cooperation between the technological air conditioning system and the heating substation was also indicated.展开更多
基金This work was supported by the National High Technology Research and Development Program of China (Grant No.2007AA041803)Doctoral.Programs Foundation of Ministry of Education of China (Grant No.20090101110041)Program for New Century Excellent Talents in University
文摘High voltage circuit breakers are the most important protection and control apparatus in power system. As a core part of circuit breakers, the operating mechanisms have a trend to be hydraulic-style in high voltage power grid. Compared with other hydranlic systems, the hydraulic operating mechanisms have the characteristics of high hydraulic pressure, high speed, high power and long-term waiting etc., and it is because of the characteristics that the hydraulic operating mechanisms become dif- ficult to be developed and have been arousing significant study interest from more and more researchers as well as their promising applications. Therefore, it is significant to summarize the hydraulic operating mechanisms on their development, characteristics, and key technologies etc. In this review, the evolution process and recent studies of hydraulic operating mechanisms at home and abroad are viewed. The review then focuses on the characteristics and key technologies of hydraulic operating mechanisms, especially on time and velocity characteristics, high-speed cylinder cushioning, fast response and great flow rate control valve, temperature compensation, system monitoring and fault diagnosis, intelligent operation, energy storage module, etc. In the end, the future trends of this field are presented.
文摘The article analyses the problem of determining the operating parameters of the district heating substation cooperating with the air heating system in technological air conditioning systems equipped with heat exchangers with high efficiency of heat recovery.Attention was paid to the correct selection of heat exchangers for the heat output balance depending on the heat recovery protection algorithms against a drop in the temperature of the heat transfer surface below 0℃.Critical parameters were determined in Polish climatic conditions,at which the operation of the heat recovery exchanger in the air conditioning system is switched off or limited.It has been proven that the proper functioning of the district heating substation cooperating with the installation of air conditioning with high heat recovery efficiency requires the use of two heat exchangers with different characteristics,equipped with properly selected temperature control systems.The optimal model of cooperation between the technological air conditioning system and the heating substation was also indicated.
