JPS6213484B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling a flow turbine in a cold-thermal power generation facility.

As is well known, when applying the Electricity Business Law, it is necessary to prevent overloading of the turbine during full load interruption.
It is necessary to suppress the flow rate to less than 111%, and since the turbine load is instantaneously attenuated during this shutdown, it is necessary to rapidly reduce the turbine flow rate.
Therefore, as shown in the first diagram, a radial expansion turbine T
This has been dealt with by placing a throttle valve (steam control valve) 2 for capacity control between the emergency shutoff valve 1 on the inlet side of the turbine, but with this method, the piping volume between the throttle valve 2 and the turbine T becomes large. There was a problem in that there was a delay in the response control, and when the throttle valve 2 was used to throttle the throttle valve, a pressure loss occurred, which lowered the expansion ratio in the turbine T, thereby reducing the turbine drive efficiency.

In view of this, a variable nozzle N whose angle can be freely changed is arranged on the outer periphery of the turbine runner 3 of the turbine T, and this is connected to an electric governor 4 and a nozzle operating device 5 as shown in FIGS. 2 and 3 to solve the above problem. In this case, as shown in Fig. 4, it can be seen that the model using the variable nozzle N is much superior to the model using the conventional throttle valve 2 in terms of insulation efficiency. Add a note to.

In this invention, variable nozzle control with excellent responsiveness, adiabatic efficiency, etc. is achieved by using two generators instead of one radial turbine and one generator as a prerequisite for control. The purpose of the present invention is to suitably realize three operating modes required in their special relationship for a turbine configured with a single generator, by means of the variable nozzle control. The feature here is that the collected gas from different processes rotates two radial flow turbines, and both turbines drive a single generator. This is a turbine control method in which variable nozzles arranged at the inlet sides of two turbines so that their angles can be changed freely are adjusted and controlled so that the nozzle openings are at the same rate, thereby controlling the rotational speed of both turbines and the output of the generator. On the other hand, the opening degree of each variable nozzle is individually adjusted to control the outlet pressure of one turbine and the inlet pressure of the other turbine to be constant in a separate and independent relationship.

The illustrated embodiment will be described below.

FIGS. 5 and 6 show in more detail the variable nozzle mechanism schematically shown in FIGS. 2 and 3, respectively, and the mechanism will be explained first.

In these figures, 6 is a turbine casing, 7 is a casing cover, and in this case, both are connected to form an introduction passage 8 in the turbine casing 6, and the internal impeller, turbine shaft, etc. are not shown. Reference numeral 9 indicates a number of nozzle fulcrum pins disposed in the circumferential direction near the end of the introduction path 8, N indicates a number of variable nozzles whose inner peripheral base ends are pivotally supported by each pin 9, and 10 indicates a number of variable nozzles on one side of the nozzle. 11 is a spindle connected to the periphery of the ring 10, and 12 is a transmission lever for responsively transmitting the nozzle. The relationship is such that it responds to the hydraulic pressure of the nozzle operating device 5.

The above is an example of a structure commonly configured for two radial turbines, and the actual cooling and heating turbine control system as a whole is as shown in Figure 7. Explain the system.

That is, there is one generator G, and there is a natural gas expansion turbine _T1 and a propane expansion turbine _T2.
are arranged in parallel and connected to the synchronous generator G via the respective reduction gears R/G and R/G. In this case, variable nozzles N ₁ and N ₂ are provided in two radial turbines T ₁ and T ₂ that drive one generator G, respectively.
The key point of the present invention is to operate separate variable nozzles N ₁ and N ₂ with one electric governor 4, that is, the speed signals from the pick-up MPs attached to the two turbine shafts 13 and 14 are controlled by the electric governor. 4, a signal is sent as a control current to an actuator, and the actuator converts the electrical signal into a mechanical displacement. Furthermore, the displacement of the actuator is amplified by the hydraulic pressure of the nozzle operating device 5, and the variable nozzle lever 12 directly connected to the operating device 5 is moved to open and close each variable nozzle N ₁ and N ₂ . The amount of gas flowing into each expansion turbine T ₁ and T ₂ is controlled, the turbine output is changed, the rotation speed is controlled, the process pressure is controlled,
Operates in three power control modes.

In the rotation speed control operation among the above modes, when operating the turbines T ₁ and T ₂ independently, when driving the synchronous generator G, the turbine
T ₁ and T ₂ themselves operate to control the rotation speed. At this time, the variable nozzle opening degrees of the two turbines T ₁ and T ₂ are set to the same ratio. In this case, since priority is given to rotation speed control, the turbine inlet and outlet pressures are controlled by turbine bypass valves V ₁ and V ₂ .

In power control operation, when performing parallel operation with power purchase, the operation is performed with priority given to the function of controlling the output of the generator G to a constant level. In this case as well, the two turbines
The opening degrees of variable nozzles N ₁ and N ₂ of T ₁ and T ₂ are set to the same ratio, and the turbine inlet and outlet pressures are controlled by turbine bypass valves V ₁ and V ₂ . Therefore, it is possible to prevent a phenomenon in which the expansion ratio of one turbine decreases during operation, resulting in compression operation, or in which the turbine flow rate stops flowing.

In process pressure control operation, parallel operation is performed with power purchase, and the operation prioritizes and controls the inlet pressure or outlet pressure of the turbine. In this case, different pressures of each turbine are controlled. Variable nozzles for two turbines
N ₁ and N ₂ have different opening degrees necessary for pressure control. At this time, the turbine bypass valve
V ₁ and V ₂ are in a closed state.

The feature of the present invention is that the three operating modes described above can be performed using the variable nozzles N ₁ and N ₂ of the two turbines.

Note that the illustrated PICs 1 to 4 indicate pressure regulators, and although two reducers R/G are provided in the above example, they may be combined into a single reducer.

As described above, the present invention is very advantageous because it uses a variable nozzle, has a small stroke, has excellent control response, and has no pressure loss and is also excellent in efficiency during partial load operation. In a model in which one generator is rotationally driven by two turbines, each variable nozzle can be selectively controlled to have the same opening rate or different opening degrees, making it possible to effectively obtain each of the three operating modes described above. We have now been able to do it. Additionally, since the integration of two turbines and one generator requires only one generator, it is not only advantageous in terms of cost and construction work, but also has the advantage of requiring a small installation area.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of an expansion turbine with a throttle valve, FIG. 2 is a schematic diagram showing a flow rate adjusting means using a variable nozzle, and FIG. 3 is a cross-sectional schematic diagram of the same means.
Figure 4 is a comparison diagram of adiabatic efficiency depending on the turbine capacity control method, Figure 5 is a cross-sectional view of the main part of a turbine with a variable nozzle, Figure 6 is a cross-sectional view along line A-A, and Figure 7 is cold turbine control. FIG. 2 is a process flow diagram showing the system. T, T ₁ , T ₂ ... Radiation turbine, N, N ₁ , N ₂ ...
...Variable nozzle, G... Generator.

Claims (1)

[Claims] 1. A method for controlling a radiant turbine in a cold thermal power generation facility in which two radiant turbines are rotationally driven by gases recovered from different processes, and a single generator is driven by both turbines, comprising: 2
The variable nozzles placed on each inlet side of the main turbine can be adjusted and controlled so that the nozzle openings are at the same rate to control the rotational speed of both turbines and the output of the generator. 1. A method for controlling a radial turbine in a cold-thermal power generation facility, characterized by controlling the opening of one turbine and the inlet pressure of the other turbine in a separate and independent relationship by adjusting the opening.