is smaller. After the system pressure is established, the pressure difference before
and after the loading valve decreases gradually, the flow rate increases rapidly, and
the resistance decreases. At this time, the pressure building process of the starting
section is completed.
9.5.4 Starting Characteristics of Power Supply System
The starting time t r of power supply system is based on the time when the motor
frequency reaches a certain value, and the motor frequency can also be regarded as
the EHPU rotation speed, that is to say, to improve the starting speed of the starting
section, so that the system can accelerate the starting and achieve a higher speed in
a short time. Therefore, the performance index of the starting section of gas generator is particularly important, which is related to the starting power and directly
affects the starting characteristics of the system.
9.5.4.1 Effect of Gas Peak Pressure on Starting Characteristics
The speed of EHPU starting section is related to inertia J and load Z of EHPU itself,
as well as peak pressure of gas generator starting section. It can be described as
n t
ð Þ ¼ f p max ; J; Z
ð
Þ
ð 9:67Þ
As shown in Fig. 9.57, increasing peak pressure of gas generator, i.e., increasing
starting power, gas pressure at different peak pressures of 1, 2, 3, 4, and starting
characteristic relationship between motor frequency and time change process are
shown in Fig. 9.57. From the figure, it can be seen that increasing peak gas pressure
is effective for accelerating the start of the system, and the effect is remarkable,
which has been verified in many key experiments.
However, in the EHPU system, the peak gas pressure cannot be raised too high.
On the one hand, it is limited by the structural strength, and on the other hand, the
frequency of the motor is also limited to a certain extent, the voltage cannot be too
high, otherwise the power supply system is unstable. Therefore, the selection of
peak gas pressure should be within an appropriate range.
9.5.4.2 Effect of Pressure Impulse on Starting Characteristics
Starting characteristic requirement of power supply system refers to a certain frequency and voltage requirement within a certain period of time, that is, the starting
and accelerating accumulative time of EHPU. For the pressure of gas generator, it is
the accumulation of pressure impulse, as shown in Fig. 9.58.
156
9 High-Temperature and High-Speed Gas Turbine Pump …
and after the loading valve decreases gradually, the flow rate increases rapidly, and
the resistance decreases. At this time, the pressure building process of the starting
section is completed.
9.5.4 Starting Characteristics of Power Supply System
The starting time t r of power supply system is based on the time when the motor
frequency reaches a certain value, and the motor frequency can also be regarded as
the EHPU rotation speed, that is to say, to improve the starting speed of the starting
section, so that the system can accelerate the starting and achieve a higher speed in
a short time. Therefore, the performance index of the starting section of gas generator is particularly important, which is related to the starting power and directly
affects the starting characteristics of the system.
9.5.4.1 Effect of Gas Peak Pressure on Starting Characteristics
The speed of EHPU starting section is related to inertia J and load Z of EHPU itself,
as well as peak pressure of gas generator starting section. It can be described as
n t
ð Þ ¼ f p max ; J; Z
ð
Þ
ð 9:67Þ
As shown in Fig. 9.57, increasing peak pressure of gas generator, i.e., increasing
starting power, gas pressure at different peak pressures of 1, 2, 3, 4, and starting
characteristic relationship between motor frequency and time change process are
shown in Fig. 9.57. From the figure, it can be seen that increasing peak gas pressure
is effective for accelerating the start of the system, and the effect is remarkable,
which has been verified in many key experiments.
However, in the EHPU system, the peak gas pressure cannot be raised too high.
On the one hand, it is limited by the structural strength, and on the other hand, the
frequency of the motor is also limited to a certain extent, the voltage cannot be too
high, otherwise the power supply system is unstable. Therefore, the selection of
peak gas pressure should be within an appropriate range.
9.5.4.2 Effect of Pressure Impulse on Starting Characteristics
Starting characteristic requirement of power supply system refers to a certain frequency and voltage requirement within a certain period of time, that is, the starting
and accelerating accumulative time of EHPU. For the pressure of gas generator, it is
the accumulation of pressure impulse, as shown in Fig. 9.58.
156
9 High-Temperature and High-Speed Gas Turbine Pump …