system is restricted by many factors. Excessive pressure means taking risks.
Corrosion and dirt will cause serious wear and tear in the flow path under high
pressure. In order to adapt to the extremely high working pressure, the strength
and wall thickness of components will increase greatly, resulting in the increase
of volume and weight or the decrease of working area and displacement. In the
case of a given load, the reduction of displacement and working area caused by
high working pressure will make the resonance frequency of hydraulic
machinery lower and bring difficulties to control. Therefore, it can be foreseen
that a series of key basic theories need to be solved in order to greatly increase
work pressure.
(2) Energy-saving and efficiency-enhancing
Efficiency has always been one of the most concerned issues. Hydraulic drive
can easily provide enough power for the load to move, especially in a straight
line, which is its obvious advantage over electric drive. However, due to
throttling loss and volume loss, its energy consumption is large and its efficiency is not very high. Although hydraulic drive has its own unique advantages compared with traditional mechanical drive, it should be noted that the
electric drive industry is progressing rapidly and is developing toward the
direction of small size and high power. The wires used are getting thinner and
the working current is getting bigger and bigger. The development and application of room temperature superconducting materials is a great impetus to the
application of electric drive. It means energy-saving, which is the future
direction of development. If the hydraulic system does not develop in the
direction of energy-saving and efficiency-increasing, the electric drive will
probably encroach on the exclusive application fields of hydraulic drive,
especially those applications requiring large force, high speed, and linear
motion.
(3) Integrated sensitive element/sensor
Sensitive elements or sensors help to monitor, control, and adjust the parameters of the electro-hydraulic system. They also play an important role in the
combination of hydraulic technology and microelectronic control. Integrative
sensor structure is the direction of development, because it helps to improve the
dynamic response and reliability of the system. The electro-hydraulic device
provides matching sensitive elements or sensors. The sensors used in the
electro-hydraulic system have the ability to store and correct data. The
microelectronic control device downloads the data and interprets and translates
it. The development of multipurpose interface devices enables users to select
any kind of sensitive elements; the host computer will identify the types of
sensitive elements used, such as digital or analog, serial or parallel, and
translate their output. Modern control theory, such as state variable feedback
control, can effectively improve the response of electro-hydraulic system. On
the basis of the dynamic characteristics of valves and other components, this
technology requires not only measurement and feedback of controlled output,
but also some key variables in the system, such as internal pressure. These state
54
9 High-Temperature and High-Speed Gas Turbine Pump …
Corrosion and dirt will cause serious wear and tear in the flow path under high
pressure. In order to adapt to the extremely high working pressure, the strength
and wall thickness of components will increase greatly, resulting in the increase
of volume and weight or the decrease of working area and displacement. In the
case of a given load, the reduction of displacement and working area caused by
high working pressure will make the resonance frequency of hydraulic
machinery lower and bring difficulties to control. Therefore, it can be foreseen
that a series of key basic theories need to be solved in order to greatly increase
work pressure.
(2) Energy-saving and efficiency-enhancing
Efficiency has always been one of the most concerned issues. Hydraulic drive
can easily provide enough power for the load to move, especially in a straight
line, which is its obvious advantage over electric drive. However, due to
throttling loss and volume loss, its energy consumption is large and its efficiency is not very high. Although hydraulic drive has its own unique advantages compared with traditional mechanical drive, it should be noted that the
electric drive industry is progressing rapidly and is developing toward the
direction of small size and high power. The wires used are getting thinner and
the working current is getting bigger and bigger. The development and application of room temperature superconducting materials is a great impetus to the
application of electric drive. It means energy-saving, which is the future
direction of development. If the hydraulic system does not develop in the
direction of energy-saving and efficiency-increasing, the electric drive will
probably encroach on the exclusive application fields of hydraulic drive,
especially those applications requiring large force, high speed, and linear
motion.
(3) Integrated sensitive element/sensor
Sensitive elements or sensors help to monitor, control, and adjust the parameters of the electro-hydraulic system. They also play an important role in the
combination of hydraulic technology and microelectronic control. Integrative
sensor structure is the direction of development, because it helps to improve the
dynamic response and reliability of the system. The electro-hydraulic device
provides matching sensitive elements or sensors. The sensors used in the
electro-hydraulic system have the ability to store and correct data. The
microelectronic control device downloads the data and interprets and translates
it. The development of multipurpose interface devices enables users to select
any kind of sensitive elements; the host computer will identify the types of
sensitive elements used, such as digital or analog, serial or parallel, and
translate their output. Modern control theory, such as state variable feedback
control, can effectively improve the response of electro-hydraulic system. On
the basis of the dynamic characteristics of valves and other components, this
technology requires not only measurement and feedback of controlled output,
but also some key variables in the system, such as internal pressure. These state
54
9 High-Temperature and High-Speed Gas Turbine Pump …