JPS5951659B2 - Automotive gas turbine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a two-shaft gas turbine engine for an automobile.

Generally, in two-wheel gas turbine engines for automobiles, the first
As shown in the figure, the engine 1 is controlled so that the required output is obtained by mainly changing the flow rate Wf of the supplied fuel and the angle α of the power turbine inlet variable guide vane (hereinafter abbreviated as VN). .

The rotation speed Ngg of the gas generator shaft is controlled in accordance with the fuel flow rate Wf, while the VN angle α is usually controlled to prevent compressor surge and to allow the engine to operate at a high efficiency.

Specifically, a subtracter 7 calculates the deviation between the gas generator rotational speed instruction signal Nggset from the accelerator 5 and the actual gas generator rotational speed Ngg, and then this deviation ΔNgg is calculated by a calculation circuit 9 (usually a proportional By inputting the fuel flow rate instruction value CVset into the integral) and driving the actuator 11 according to this instruction value, the gas generator rotation speed Ngg
The flow rate Wf is increased or decreased so that the command value Nggset becomes the command value Nggset, thereby securing the required output according to the amount of accelerator depression.

On the other hand, in the calculator 15, the gas generator corrected rotation speed Ngg *= is determined from the engine intake air temperature T1 and the rotation speed Ngg.
Ngg~? is calculated and determined, and the corrected compressor turbine inlet temperature T7set* as shown in FIG. 2 is determined from this corrected rotation speed Ngg*.

Next, T7Set**×T1 is calculated to obtain the compressor turbine inlet temperature command value T7Set, and the deviation between this and the actual compressor turbine inlet temperature T7 is calculated using the subtractor [8
This deviation ΔT7 is calculated by the calculation circuit 20 (
(usually proportional integral) to obtain the VN angle instruction value VNset.

By driving the actuator 22 according to this instruction value, the compressor turbine inlet temperature T7 is adjusted to the instruction value T.
7set, change the VN angle α to control the flow velocity direction of the high temperature gas to the power turbine,
Prevent compressor surges and better control engine efficiency.

By the way, from the viewpoint of heat resistance of the turbine, the predetermined upper limit T7
It is necessary to control the turbine temperature T7 so as not to exceed MAX. Conventionally, the selector 24 sets the indicated value T7Se.
Compare t with upper limits T7 and IAX, select the smaller value, and set this as the actual turbine population temperature command value T7Set.
It is set as 1.

However, such control has the drawback that when the engine intake air temperature T1 rises above normal, the maximum output of the engine decreases significantly.

In other words, the aerodynamic design of the engine is designed to be most efficient at room temperature, so at maximum output, VN
is set to the angle that facilitates the most output, and the compressor turbine inlet temperature T7 is set to the 1st limit T7MAX.

However, at the same rotational speed Ngg and VN angle, when the intake air temperature T1 increases, the population temperature T7 increases significantly due to the similarity law of turbomachines.

At this time, if the maximum load is requested from the engine, the rotational speed Ng
g increases, but the indicated value T7set is 1 limit T7MA
Since it becomes larger than X, VN is forcibly opened, resulting in a larger output reduction than that caused simply by an increase in engine inlet temperature.

This situation is shown in FIG.

The present invention overcomes the drawbacks of such conventional devices.
A device that allows the engine to always produce the maximum output that can be achieved at the current intake air temperature, thereby minimizing the reduction in maximum output due to a sudden rise in intake air temperature while maintaining engine safety. It provides:

The present invention will be described below based on embodiments shown in the drawings.

FIG. 4 shows the first embodiment, in which 26 and 28 are comparators, and 26a and 28a are switch circuits.

The comparator 26 has a predetermined reference rotation speed NggL set in advance.
& Gas generator rotation speed Ngg, the rotation speed Ngg
is the reference rotation speed Nggt, (for example, 90% of the maximum rotation speed
), the contact of the switch circuit 26a is switched to set the VN angle command value VNs based on the turbine inlet temperature.
Instead of et, an instruction value VNF is sent to the actuator 22 to fix VN at an angle that will most easily produce engine output at room temperature.

The comparator 28 compares the compressor turbine population temperature T7 with the upper limit 'Luax', and the temperature T7.
When the upper limit of power exceeds 7MAX, switch circuit 2
Switch the contact point 8a to set the command value CVset 41N, which narrows down and fixes the fuel supply amount to the minimum required amount to lower the temperature of the compressor turbine below the upper limit and avoid heat loss, instead of the fuel flow command value CVset. The signal is sent to the actuator 11.

The other configurations are the same as those in FIG. 1, so the same parts are given the same reference numerals.

Therefore, in this embodiment, when the rotation speed Ngg exceeds the reference rotation speed Ngg+, vN based on the temperature condition
Stop the variable control and fix VN at the angle that will most easily produce engine output.

Therefore, when the accelerator 5 is pressed heavily to request maximum load (maximum output) when the intake air temperature is high, the rotation speed Ngg increases and the turbine population temperature T7 increases.
Even if it rises to the ffjJ position, VN will not open too much unlike during normal feedback control.

On the other hand, the upper limit of the fuel flow rate is T7MA, which is the turbine population temperature T7.
As long as X is not exceeded, the amount is controlled to increase in accordance with the rotational speed Ngg even if the reference rotational speed NggL is exceeded.

Therefore, regarding VN angle control, it is possible to prevent a forced reduction in engine output when a large output is required due to high intake air temperature, and to adjust the maximum output that can be achieved according to the intake air temperature at that time to the request. It is now possible to demonstrate
It is possible to minimize a decrease in output when a large output is required due to a rise in intake air temperature.

Therefore, as shown in FIG. 3, the output performance of the engine when the maximum output is required can be significantly improved compared to the conventional device.

Note that the compressor turbine inlet temperature T7 is the upper limit T7.
When MAX is exceeded, the fuel flow rate is reduced to the minimum required amount to suppress the rise in temperature T7, so damage to the turbine due to excessive heat can be prevented in the same way as with conventional devices.

FIG. 5 shows a second embodiment of the invention.

In this embodiment, when the compressor turbine inlet temperature T7 exceeds the upper limit T7MAX, the command value NLO corresponding to when the accelerator is opened at a small opening is transmitted through the first-order delay circuit 32.
tlt+ is supplied to the subtracter 7 in place of the instruction value Nggset to narrow down the fuel flow rate to the minimum required amount.

The rest is exactly the same as the first embodiment, and this embodiment exhibits the same effects as the first embodiment.

FIG. 6 shows a third embodiment of the present invention.

In this example, the deviation ΔNgg is set to a predetermined limit ΔNggM
If Ax is exceeded, the contact of the switch circuit 30a is switched according to the output of the comparator 30, and the indicated value ■NF, x2 that slightly opens the VN angle is supplied to the actuator 22, and the gas generator rotates. I try to avoid surges in places where the number Ngg is high.

The rest is exactly the same as the first embodiment, and this embodiment exhibits the same effects as the first embodiment.

By the way, the compressor turbine inlet temperature T7 rises, the command value CvSetM1N is supplied to the actuator 11, and the gas generator rotation speed Ngg and the command value Nggset
If the deviation from It is recommended to set it to zero.

Further, even if the turbine outlet temperature is used instead of the turbine population temperature T7, the same control can be performed although the accuracy and responsiveness are somewhat deteriorated.

As explained above, in the present invention, when the gas generator rotational speed exceeds the reference value, VN is fixed at the angle where the engine output is most easily produced, so that the demand can be met even when the intake air temperature rises. Accordingly, the maximum output can be exerted, and a forced decrease in output when a large output is required due to a rise in intake air temperature can be minimized.

On the other hand, when the temperature of the compressor turbine exceeds a predetermined upper limit, the fuel flow rate is reduced to reduce the heat load, thereby maintaining the safety of the turbine.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional device, FIG. 2 is a diagram showing the relationship between corrected compressor turbine inlet temperature and corrected rotation speed, and FIG. 3 is an engine diagram showing the relation between intake air temperature in the conventional device and the device of the present invention. 4 is a block diagram showing the first embodiment of the present invention, FIG. 5 is a block diagram showing the second embodiment, and FIG. 6 is a block diagram showing the third embodiment. It is a diagram. DESCRIPTION OF SYMBOLS 1... Engine, 5... Accelerator, 7... Subtractor, 9... Arithmetic circuit, 11... Actuator, 1
5... Arithmetic unit, 18... Subtractor, 20... Arithmetic circuit, 22... Actuator, 24... Selector,
26... Comparator, 26a... Switch circuit, 28.
...Comparator, 28a...Switch circuit, 30...Comparator, 30a...Switch circuit, 32...First-order lag circuit.

Claims (1)

[Scope of Claims] 1. A gas generator shaft and a power turbine shaft that rotate independently of each other, a variable blade disposed at the inlet of the power turbine, and a deviation between the indicated value and the gas generator shaft rotational speed based on the amount of accelerator depression. means for increasing or decreasing the amount of fuel supplied in a direction to reduce the amount of fuel supplied, and an angle of the device to reduce the deviation between the compressor turbine inlet or outlet temperature and the indicated value based on the gas generator shaft rotation speed and engine intake air temperature. In an automobile gas turbine engine equipped with variable control means, when the gas generator shaft rotation speed exceeds a predetermined set value, means for fixing the above-mentioned tool at a predetermined angle at which the output efficiency of the engine is good at room temperature. and means for reducing the amount of fuel supplied to a predetermined amount when the compressor turbine inlet or outlet temperature exceeds a predetermined set value. 2. If the deviation between the indicated value based on the amount of depression of the accelerator pedal and the rotation speed of the gas generator shaft exceeds a predetermined setting value, the above tool shall be used at a predetermined amount slightly below the angle at which the output efficiency of the engine is optimal. The gas turbine control device for an automobile according to claim 1, which is fixed at an angle.