JPH0565808A - Steam turbine plant supplying heat - Google Patents

Abstract

PURPOSE:To reduce loss of available energy due to the supply of steam to a process to improve the power efficiency of a plant by providing a steam compressor for boosting pressure-controlled bleed steam or exhaust steam, and a pressure control means for controlling the pressure of steam sent from the steam compressor to high level pressures. CONSTITUTION:A signal of the detected pressure of steam detected by a pressure detector 45 is inputted to a rotating speed controller 46, the controller 46 controls the rotating speed of a motor 40, namely the rotating speed of a steam compressor 41, and thus the pressure of high pressure process steam is controlled to a specified pressure to be supplied to a high pressure process 9. On the other hand, a signal of the detected temperature of steam detected by a temperature detector 47 is inputted to a temperature controller 49. The controller 49 controls the quantity of a water injection valve 48 to decrease the temperature, and thus the temperature of high pressure process steam is controlled to a specified temperature to be supplied to the high pressure process 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cogeneration steam turbine plant in which steam to be supplied to a process or the like is obtained from a steam turbine and power is obtained from the turbine.

[0002]

2. Description of the Related Art In a cogeneration steam turbine plant, it is required to take out power from a turbine and supply steam with a plurality of pressures and temperatures at different levels to a process for heating, heating, cooling, etc. Often.
In order to meet this requirement, conventional multistage extraction steam condensing turbines or multistage extraction back pressure turbines have been adopted, and extraction steam extracted from these turbines and controlled to a predetermined pressure on the turbine side (hereinafter referred to as control extraction air) or exhaust steam Is being supplied to the process.

On the other hand, the number of control bleed air that can be extracted from the turbine is limited due to structural restrictions of the turbine. From these points, only steam that can be supplied conventionally is taken as controlled bleed air from the turbine, and other steam is bypassed from the turbine upstream or steam extracted from the turbine stage with a sufficiently high pressure (hereinafter referred to as uncontrolled bleed air) is throttled. The pressure is reduced and the temperature is reduced through the valve.

The prior art will be described below with reference to the drawings. FIG. 6 is a system diagram of a cogeneration steam turbine plant that employs a conventional extraction back pressure turbine. In FIG. 6, a boiler 1 that generates high-pressure and high-temperature steam is connected to a bleed back pressure turbine 3 via a main steam supply system 2. The extraction back pressure turbine 3 is composed of a high pressure turbine section 4 and a low pressure turbine section 5, and is provided with a main steam control valve 6 at the inlet of the high pressure turbine section 4 and an extraction control valve 7 at the inlet of the low pressure turbine section 5.
The generator 8 is connected to the extraction back pressure turbine 3.

A high pressure process steam supply destination (hereinafter referred to as a high pressure process) 9 is connected to an exhaust portion of the high pressure turbine section 4 via a high pressure process steam system 10. The high-pressure process steam system 10 has a temperature reducer 12 equipped with a water injection valve 11 and a check valve 1.
3 and 3. The temperature controller 14 controls the water injection valve 11 based on the deviation between the detected temperature of the high pressure process vapor supplied to the high pressure process 9 detected by the temperature detector 15 and the target temperature of the predetermined temperature supplied to the high pressure process 9. The amount of water is controlled, and the dewatering device 12 mixes the injected water with the steam to reduce the temperature of the steam flowing through the high-pressure process steam system 10 to control the temperature.

A low-pressure process steam supply destination (hereinafter referred to as a low-pressure process) 16 is connected to an exhaust section of the low-pressure turbine section 5 via a low-pressure process steam system 17, and has a temperature detector 18 and a desuperheater 19 having the same operations as described above. A water injection valve 20 and a temperature controller 21 are provided.

The pressure controller 22 supplies the high pressure and low pressure process vapors supplied to the high pressure process 9 and the low pressure process 16 respectively with the detected pressures detected by the pressure detectors 23 and 24 and the high pressure process 9 and the low pressure process 16, respectively. Main steam control valve 6, bleed control valve 7 based on the deviation of each target pressure from the specified pressure
To control.

With this structure, the high-pressure, high-temperature steam generated in the boiler 1 flows into the extraction back pressure turbine 3 via the main steam supply system 2, and the high-pressure turbine section 4 and the low-pressure turbine section 5
At that time, expansion work is performed to generate power, and the power is discharged from the low-pressure turbine unit 5. The power generated by the turbine is converted into electric power by the generator 8 and supplied to the load.

The high pressure process 9 and the high pressure process steam system 10
Pressure process steam and low pressure process 1 supplied via
The low-pressure process steam supplied to 6 through the low-pressure process steam system 17 is input to the pressure regulator 22 by the signal of the detected pressure detected by the pressure detector 23 and the pressure detector 24, and this regulator controls the main steam control valve. 6. The pressures of the high-pressure process steam and the low-pressure process steam controlled by the extraction control valve 7 are controlled to predetermined pressures to be supplied to the high-pressure process 9 and the low-pressure process 16, respectively.

As for the temperature of the high-pressure process steam supplied to the high-pressure process 9, a signal of the detected temperature detected by the temperature detector 15 is input to the temperature controller 14, and this controller controls the water injection valve 11 to reduce the temperature. The temperature is reduced by the vessel 12 and controlled to a predetermined temperature to be supplied to the high pressure process 9.

The temperature of the low-pressure process steam supplied to the low-pressure process 16 is controlled by the temperature detector 18, the temperature controller 21, the water injection valve 20, and the desuperheater 19 as in the above.
It is controlled to a predetermined temperature to be supplied to No. 6.

FIG. 7 is a system diagram of a cogeneration steam turbine plant adopting a conventional back pressure turbine. In FIG. 7, the same parts as those in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted. In the figure, the high pressure process 9 is an uncontrolled extraction point 2 for extracting uncontrolled extraction air from the high pressure section in the middle of the back pressure turbine 25.
6 via a high pressure process steam system 10, and the high pressure process steam system 10 is provided with a pressure adjusting valve 27. The pressure regulator 28 controls the pressure regulating valve 27 based on the deviation between the detected pressure of the high pressure process vapor supplied to the high pressure process 9 detected by the pressure detector 29 and the target pressure of the predetermined pressure supplied to the high pressure process 9.

The low pressure process 16 is connected to the exhaust portion of the back pressure turbine 25 via a low pressure process steam system 17.

The pressure regulator 30 is a low pressure process steam system 17
The main steam control valve 6 is controlled from the deviation between the detected pressure detected by the pressure detector 24 of the low pressure process steam supplied to the low pressure process 16 and the target pressure of the predetermined pressure supplied to the low pressure process 16.

With such a structure, the high-pressure, high-temperature steam generated in the boiler 1 flows into the back-pressure turbine 25, performs expansion work, and is exhausted to generate power. This power is converted into electric power by the generator 8 and supplied to the load.

The high pressure process 9 is supplied with the high pressure process steam extracted from the uncontrolled extraction point 26 of the back pressure turbine 25 through the high pressure process steam system 10, and its pressure is equal to the detected pressure detected by the pressure detector 29. Signal is pressure regulator 28
Is input to the pressure control valve 27 by this controller to control it to a predetermined pressure to be supplied to the high pressure process 9, and its temperature is controlled by the temperature detector 15, the temperature controller 14, the water injection valve 11 as described above. High-pressure process 9 in the desuperheater 12
Is controlled to a predetermined temperature to be supplied to.

Exhaust steam from the back pressure turbine 25 is supplied to the low-pressure process 16 as a low-pressure process steam via the low-pressure process steam system 17, and the pressure of the exhaust pressure steam detected by the pressure detector 24 is a pressure regulator 30. Is input to the main steam control valve 6 by this controller to control it to a predetermined pressure to be supplied to the low pressure process 16, and its temperature is controlled by the temperature detector 18, the temperature controller 21, the water injection valve as described above. 20. The temperature reducer 19 controls the temperature to a predetermined temperature to be supplied to the low pressure process 16.

FIG. 8 is a system diagram of a cogeneration steam turbine plant equipped with a back pressure turbine 25 that obtains high-pressure process steam to be supplied to a conventional high-pressure process 9 by a bypass system that bypasses the turbine from upstream of the turbine. In order to supply high-pressure process steam to the high-pressure process 9 in FIG. 8, a pressure detector 29, a pressure adjusting valve 27, a temperature detector 15, and a desuperheater 12 are provided in a bypass system 32 branched from the main steam supply system 2. Furthermore, pressure controller 28, temperature controller 1
4. The same as FIG. 7 except that the water injection valve 11 is provided.

With such a structure, the high-pressure, high-temperature steam from the boiler 1 flows into the back pressure turbine 25 to perform expansion work to generate power, which is exhausted from the exhaust section. As described above, this power is converted into electric power by the generator 8 and supplied to the load.

The high pressure process 9 includes high pressure from the boiler 1,
A part of the high temperature steam is supplied as high pressure process steam through the bypass system 32. As for the pressure of this high-pressure process steam, a signal of the detected pressure detected by the pressure detector 29 is input to the pressure regulator 28, and this regulator regulates the pressure regulating valve 2
7 is controlled to a predetermined pressure to be supplied to the high-pressure process 9, and a signal of the temperature detected by the temperature detector 15 is input to the temperature controller 14, and the water injection valve 11 is controlled by this controller. Is controlled by the desuperheater 12 to be controlled to a predetermined temperature to be supplied to the high pressure process 9.

The low-pressure process steam supplied to the low-pressure process 16 has the same pressure as that shown in FIG.
The temperature is controlled to a predetermined pressure and a predetermined temperature which are supplied to the low pressure process.

FIG. 9 is a system diagram of a cogeneration steam turbine plant having a bypass back pressure turbine in the bypass system 32 in FIG. The difference between FIG. 9 and FIG. 8 is as follows. The bypass back pressure turbine 33 is connected to the bypass system 3
2 for the high pressure process 9 and the bypass back pressure turbine 3
Exhaust steam No. 3 is supplied as high pressure process steam. The bypass back pressure turbine 33 includes a main steam control valve 35, and a generator 36 is connected to the main steam control valve 35. Further, in order to control the pressure of the exhaust steam of the bypass back pressure turbine 33, that is, the pressure of the high-pressure process steam supplied to the high-pressure process 9, the deviation between the pressure detected by the pressure detector 29 and the target pressure of the predetermined pressure supplied to the high-pressure process 9. Is provided with a pressure regulator 37 for controlling the main steam control valve 35.

With such a structure, a part of the high-pressure, high-temperature steam from the boiler flows into the back pressure turbine 25 through the main steam supply system 2, and the remaining steam passes through the bypass system 32 and the bypass back. It flows into the pressure turbine 33, expands work in each turbine to generate power, and is exhausted from the exhaust unit. The power generated by each turbine is converted into electric power by the generators 8 and 36 and supplied to the load.

Exhaust steam from the bypass back pressure turbine 33 is supplied to the high-pressure process 9 as high-pressure process steam, and the pressure of the exhaust pressure steam detected by the pressure detector 29 is input to the pressure regulator 37. The main steam control valve 35 is controlled by the reactor to a predetermined pressure to be supplied to the high pressure process 9, and its temperature is controlled to a predetermined temperature to be supplied to the high pressure process 9 as described above.

The pressure and temperature of the low pressure process steam supplied to the low pressure process 16 are controlled in the same manner as described above.

[0026]

In the cogeneration steam turbine plant equipped with the extraction back pressure turbine shown in FIG. 6, the process steam supplied to the high pressure process 9 is discharged from the discharge part of the high pressure turbine part 3, and This is control bleed air in which the pressure is controlled, and as a result, additional throttle loss, leakage loss, and paragraph loss occur in the turbine, which has the drawback of reducing the internal efficiency of the turbine and reducing the power efficiency.

In the cogeneration steam turbine plant equipped with the back pressure turbine shown in FIG. 7, the process steam extracted from the uncontrolled extraction point 26 of the back pressure turbine 25 is processed by the high pressure process 9
In consideration of the fluctuation of the load, it is necessary to select the uncontrolled extraction point 26 having a sufficiently high pressure and temperature. For this reason, there is a drawback in that the pressure adjustment valve 27 causes a throttle loss and a loss due to a decrease in temperature.

In the cogeneration steam turbine plant in which the process steam supplied to the high-pressure process 9 shown in FIG. 8 is supplied by the bypass system from the upstream of the turbine, the bypass system 3 is used.
When controlling high pressure and high temperature steam from the boiler 1 flowing through the high pressure process 9 to the high pressure process 9 at a predetermined pressure and a predetermined temperature, the loss due to the throttling by the pressure regulating valve 27 and the loss due to the temperature decrease are less than those shown in FIG. It has the drawback of becoming larger.

In the cogeneration steam turbine plant having the bypass back pressure turbine in the bypass system 32 shown in FIG.
By providing a bypass back pressure turbine in place of the pressure control valve 27 shown in FIG. 8, power can be recovered, but since the steam volume flow rate is small, it is difficult to design a bypass back pressure turbine with good turbine efficiency. Moreover, there is a drawback that the construction cost becomes high.

An object of the present invention is to prevent a decrease in turbine internal efficiency due to the provision of control bleed air as shown in the above-mentioned conventional example, and to supply steam to the process through an uncontrolled bleed point or a bypass system. It is an object of the present invention to provide a cogeneration steam turbine plant capable of reducing the effective energy loss generated in the above.

[0031]

In order to solve the above-mentioned problems, according to the present invention, in a cogeneration steam turbine plant in which power and process are co-fed with a plurality of different levels of pressure and temperature of steam, said different levels are provided. Among these, a steam compressor that expands the steam of the upper level pressure and temperature to the lower level pressure in the steam turbine and boosts the pressure-controlled extracted steam or exhaust steam, and the steam compressor that delivers the steam. And a pressure control means for controlling the pressure of the steam to the upper level pressure.

The above-mentioned pressure control means is based on the pressure detector for detecting the pressure of the vapor sent from the vapor compressor to the process, and the deviation between the pressure detected by this pressure detector and the target value of the upper level pressure. And a control means for controlling the rotation speed of the vapor compressor.

The pressure control means detects the pressure of the steam sent from the steam compressor to the process, a pressure control valve provided on the discharge side or the suction side of the steam compressor, and the pressure detection means. And a control means for controlling the pressure adjusting valve provided on the discharge side or the suction side based on the deviation between the pressure detected by the container and the target value of the upper level pressure.

In the above co-heat steam turbine plant, in addition to the pressure control means, temperature control means for controlling the temperature of the steam sent from the steam compressor to the process to the upper level temperature is provided.

The temperature control means detects the temperature of the vapor sent from the vapor compressor to the process, and
Provision of a water injection desuperheater provided on the suction side of the vapor compressor, and control means for controlling the water injection amount of the water injection desuperheater based on the deviation between the temperature detected by the temperature detector and the target value of the upper level temperature And

Further, the temperature control means detects a temperature of the steam sent from the steam compressor to the process, a first water injection desuperheater provided on the suction side of the steam compressor, and a discharge. The second water injection desuperheater provided on at least one of the side and the vapor compression intermediate stage, and the first and second water injection dehumidification heat from the deviation between the temperature detected by the temperature detector and the target value of the upper level temperature. A control means for controlling the water injection amount of the vessel shall be provided.

[0037]

[Function] When steam having different pressures and temperatures of different levels are supplied as process steam from the steam turbine, steam having higher pressure and temperature of these different levels is not extracted from the turbine. The expansion work is performed in the turbine to a lower level pressure that is pressure controlled, and the extracted steam or exhaust steam is taken out from the turbine, and this extracted steam or exhaust steam is used as process steam for a process required by the lower level pressure. To do.
On the other hand, for processes requiring higher level pressure and temperature, the extracted steam or exhaust vapor at the lower level pressure is boosted and discharged by the steam compressor, and the discharged steam is pressure controlled by the pressure control means. Controlled by and supplied. If necessary, the temperature control means controls the temperature to a higher level temperature.

When the steam delivered from the vapor compressor to the process is controlled to an upper level pressure, the pressure sent from the vapor compressor to the process is detected by a pressure detector, and the detected pressure and the upper level pressure target. It is performed by controlling the rotation speed of the steam compressor from the deviation from the value.

The pressure control of the steam sent from the steam compressor to the process is carried out based on the deviation between the pressure detected by the pressure detector and the target value of the upper level pressure, on the discharge side or the suction side of the steam compressor. It is performed by controlling a pressure regulating valve provided on the side.

On the other hand, when controlling the temperature of the vapor sent from the vapor compressor to the process to an upper level temperature, the temperature of the vapor sent from the vapor compressor to the process is detected by a temperature detector, and the detected temperature and the upper level are detected. It is performed by controlling the water injection amount of the water injection desuperheater provided on the suction side of the vapor compressor based on the deviation from the target value of the temperature.

In the above temperature control, when the wetness of the steam on the suction side becomes unacceptably high for the steam compressor, in addition to the water injection desuperheater on the suction side, the discharge side of the steam compressor and the steam A water injection desuperheater is provided at least at one side of the compression middle stage, and the amount of water injection is distributed and controlled to control the temperature at a higher level to be supplied to the process.

As described above, the steam at the pressure and temperature at the steam level supplied to the process is not extracted from the turbine, and the expansion work is performed up to the steam at the lower level pressure in the turbine.
The following effects are obtained by boosting the process steam consisting of extracted steam or exhaust steam that has reached this lower level pressure with a steam compressor, and lowering the temperature to the upper level pressure and temperature if necessary to send it as process steam. There is.

1) Improvement in turbine internal efficiency due to elimination of control bleed air, increase in work amount of bleed air in the turbine, and increase in power amount due to both of them exceed the required power of the steam compressor and result. The amount of power is increased, and power plant efficiency can be improved. 2) Steam that bypasses the turbine works through the turbine, so the power of the turbine increases, which exceeds the power required by the steam compressor, resulting in an increase in the amount of power generated. On the other hand, since the steam that has passed through the turbine is cooled, when the temperature is reduced, the amount of water injection necessary for the temperature reduction is reduced, the cycle efficiency is improved, and the power plant efficiency is improved accordingly.

[0044]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of a cogeneration steam turbine plant including a back pressure turbine according to a first embodiment of the present invention.
In FIG. 1, the same parts as those in the conventional example of FIG. 7 are designated by the same reference numerals and the description thereof will be omitted. 1 differs from the conventional example in that a low-pressure process steam system 17 is branched and connected to a high-pressure process 9, and a high-efficiency steam compressor 41 driven by a motor 40 and a desuperheater provided on the suction side of the compressor are provided. Four
2. Water injection valve 48 and check valve 4 provided on the compressor discharge side
3 is provided.

In order to control the pressure of the high-pressure process steam supplied to the high-pressure process 9, a pressure detector 45 for detecting the pressure of the high-pressure process steam, and the detected pressure detected by this detector and the high-pressure process 9 are used. A rotation speed adjuster 46 that controls the rotation speed of the motor 40 based on the deviation of the supplied predetermined pressure from the target pressure is provided.

A temperature detector 47 for detecting the temperature of the high-pressure process steam for controlling the temperature of the high-pressure process steam supplied to the high-pressure process 9 and a temperature detector 47 provided on the suction side of the steam compressor 41. A temperature controller 49 that controls a water injection valve 48 that injects water into the temperature reducer 42 based on a deviation between the detected temperature detected and a target temperature of a predetermined temperature supplied to the high-pressure process 9 is provided. In addition, the temperature control is performed by the vapor compressor 41.
This is done on the suction side in order to reduce the required power of the vapor compressor 41 as much as possible.

With such a structure, the high-pressure, high-temperature steam from the boiler 1 flows into the back pressure turbine 25, where expansion work is performed in the turbine to generate power, which is then exhausted. This power is converted into electric power by the generator 8 and supplied to the load.

The exhaust steam of the back pressure turbine 25 is controlled by the main steam control valve 6 to a predetermined pressure to be supplied to the low pressure process 16, flows through the low pressure process steam system 17, and part of it is supplied to the low pressure process 16 as low pressure process steam. To be done.

The rest of the low-pressure process vapor flowing through the low-pressure process vapor system 17 is pressurized by the vapor compressor 41 via the high-pressure process vapor system 44 and supplied to the high-pressure process 9 as high-pressure process vapor.

At this time, as the pressure of the high-pressure process steam, a signal of the detected pressure of the steam detected by the pressure detector 45 is input to the rotation speed controller 46, and this rotation speed of the motor 40, that is, the steam compressor. The rotation speed of 41 is controlled to a predetermined pressure supplied to the high pressure process 9.

On the other hand, regarding the temperature of the high-pressure process steam, a signal of the detected temperature of the steam detected by the temperature detector 47 is input to the temperature controller 49, and this controller controls the water injection amount of the water injection valve 48 to reduce the temperature. The temperature is reduced by the vessel 42 and controlled to a predetermined temperature to be supplied to the high pressure process 9.

The low-pressure process steam supplied to the low-pressure process 16 via the low-pressure process steam system 17 is the same as the temperature detector 18, the desuperheater 19, the water injection valve 20, and the temperature controller 2.
1, the temperature is controlled to a predetermined temperature to be supplied to the low pressure process 16.

FIG. 2 is a system diagram of a cogeneration steam turbine plant equipped with a back pressure turbine according to a second embodiment of the present invention. In FIG. 2, the rotation speed controller 46 for controlling the rotation speed of the motor 40 of the steam compressor 41 of FIG. 1 is removed, and instead a pressure control valve 50 is provided in the high pressure process steam system 44 on the discharge side of the steam compressor 41. A pressure regulator 51 is provided which controls the pressure regulating valve 50 based on the deviation between the detected pressure signal of the steam detected by the pressure detector 45 and the target pressure of the predetermined pressure supplied to the high pressure process 9. Figure 1 except for the provision
Is the same as.

With such a configuration, as for the pressure of the steam supplied to the high-pressure process 9, a signal of the detected pressure of the steam detected by the pressure detector 45 is input to the pressure regulator 51, and the pressure regulator 51 is operated by this regulator. High pressure process 9 by controlling 50
The pressure is controlled to a predetermined pressure.

FIG. 3 is a system diagram of a cogeneration steam turbine plant equipped with a back pressure turbine according to a third embodiment of the present invention. In FIG. 3, the pressure regulating valve 50 of FIG. 2 is removed, the pressure regulating valve 52 is provided in the high-pressure process vapor system 44 on the suction side of the vapor compressor 41, and the signal of the detected pressure of the vapor detected by the pressure detector 45 is 2 except that a pressure regulator 53 for controlling the pressure regulating valve 52 is provided based on the deviation between the detected pressure input and the target pressure of the predetermined pressure supplied to the high pressure process 9.
Is the same as.

With the above-mentioned structure, the pressure of the vapor sent from the vapor compressor 41 and supplied to the high pressure process 9 is controlled by the pressure regulating valve 52 through the pressure detector 45 and the pressure regulator 53 by the same action as described above. It is controlled to a predetermined pressure.

FIG. 4 is a system diagram of a cogeneration steam turbine plant equipped with a back pressure turbine according to a fourth embodiment of the present invention. In FIG. 4, a water injection valve 54 and a temperature reducer 5 of a water injection desuperheater for injecting water into the steam flowing through the high-pressure process steam system 44 on the discharge side which is boosted and delivered by the vapor compressor 41 to lower the temperature.
5 is further provided, and the signal of the detected temperature of the steam detected by the temperature detector 47 is input, and the water injection amount is distributed based on the deviation between the detected temperature and the target temperature of the predetermined temperature supplied to the high-pressure process 9. Temperature controller 56 controlling 48 and 54
1 is the same as that shown in FIG.

With such a structure, when the degree of wetness of the exhaust steam from the back pressure turbine is high, the temperature is calculated from the deviation between the detected temperature of the steam by the temperature detector 47 and the target temperature of the predetermined temperature supplied to the high pressure process 9. Water injection valve 48 by regulator 55
And 54 are controlled by distributing their water injection amounts, and the temperature of the steam supplied to the high-pressure process 9 is controlled to a predetermined temperature.

FIG. 5 is a system diagram of a cogeneration steam turbine plant equipped with a back pressure turbine according to a fifth embodiment of the present invention. In FIG. 5, the water injection valve 54 and the temperature reducer 55 of FIG. 4 are removed, a water injection valve 57 for injecting water for temperature reduction is provided in the intermediate stage of compression, and a signal of the temperature of steam detected by the temperature detector 47 is provided. 4 is input, and a temperature controller 58 for controlling the water injection valves 48 and 54 by distributing the water injection amount from the deviation between the detected temperature and the target temperature of the predetermined temperature supplied to the high-pressure process 9 is provided. Is the same.

With such a configuration, the temperature detector 47,
The temperature regulator 56 controls the water injection valves 48 and 54 to control the temperature of the steam supplied to the high-pressure process 9 to a predetermined temperature by the same action as described above.

In FIG. 5, the water injection valve 57 for injecting water is provided in the intermediate compression stage of the vapor compressor 41, but a water injection dehumidifier is also provided on the discharge side of the vapor compressor in consideration of the wetness of the vapor. The same effect can be obtained by distributing and controlling the water injection valves on the suction side, the intermediate compression stage, and the discharge side.

The increase in construction cost associated with the installation of the steam compressor in the above-described embodiment is due to the fact that the turbine structure is simplified according to the present invention, and the steam compressor is installed near the steam consuming process. It can be fully covered by rationalizing the piping system.

In the above embodiment, the vapor compressor 41
The steam discharged from the steam compressor 4 is controlled at a predetermined temperature to be supplied to the high-pressure process 9 by the temperature control means.
If the outlet steam temperature of 1 is a predetermined temperature to be supplied to the high-pressure process 9, the temperature control means is not necessary.

In the above-mentioned embodiment, the low-level process steam as the low-pressure process steam is used as the pressure-controlled exhaust steam, but the same effect can be obtained by using the pressure-controlled bleed steam.

Further, in the above-mentioned embodiment, the process steam system of the steam having different levels of pressure and temperature supplied to the process has two
Although explained as a system, the means according to the present invention can be adopted even if there are more than two process steam systems. In this case, a plurality of high-pressure process steam systems are provided, a steam compressor is provided in each system, and the pressure control means controls the pressure to a predetermined level to be supplied to each process, and the temperature control means reduces the temperature if necessary. The temperature may be controlled.

The first embodiment shown in FIG. 1 according to the present invention
Is assumed to be case 5, and the conventional examples shown in FIGS. 6 to 9 are assumed to be cases 1 to 4, respectively. Assuming the actual conditions, the plant outputs that can be extracted for each case are compared and calculated, and the results shown in FIG. 10 are obtained. Was given. Referring to FIG. 10, the case 5 of the embodiment of the present invention and the cases 1 to 4 of the conventional example
On the other hand, it is understood that the plant output gas increases by 2 to 10%.

[0067]

As is apparent from the above description, according to the present invention, when a plurality of steams having different pressures and temperatures are supplied as process steams, steam having an upper level pressure and temperature is supplied to the steam turbine. The expansion work is performed up to a lower level pressure by using the low pressure steam as process steam, and a vapor compressor that boosts the pressure of this process steam is installed, and the steam sent from this compressor is controlled to a higher level pressure. In order to use process steam, by providing the pressure control means by the rotation speed control of the steam compressor or the pressure adjustment valve, and the temperature control means consisting of the water pouring desuperheater for controlling the temperature, Since it is no longer necessary to use controlled extraction air, uncontrolled extraction air, or steam that bypasses the turbine as process steam, the power efficiency of the plant is improved. Even if the vapor compressor is used, the plant output taken out is increased as compared with the conventional one, and for example, as shown in FIG. 10, the plant output taken out from the one according to the present invention is increased by 2 to 10% as compared with the conventional one. ..

[Brief description of drawings]

FIG. 1 is a system diagram of a cogeneration steam turbine plant according to a first embodiment of the present invention.

FIG. 2 is a system diagram of a cogeneration steam turbine plant according to a second embodiment of the present invention.

FIG. 3 is a system diagram of a cogeneration steam turbine plant according to a third embodiment of the present invention.

FIG. 4 is a system diagram of a cogeneration steam turbine plant according to a fourth embodiment of the present invention.

FIG. 5 is a system diagram of a cogeneration steam turbine plant according to a fifth embodiment of the present invention.

FIG. 6 is a system diagram of a conventional cogeneration steam turbine plant of Case 1.

FIG. 7 is a system diagram of a conventional cogeneration steam turbine plant of case 2

FIG. 8 is a system diagram of a conventional cogeneration steam turbine plant of case 3

FIG. 9 is a system diagram of a conventional cogeneration steam turbine plant of case 4

FIG. 10 is a diagram showing a comparison of plant outputs of a cogeneration steam turbine plant according to the present invention and a conventional one.

[Explanation of symbols]

 9 High Pressure Process 16 Low Pressure Process 25 Back Pressure Turbine 41 Steam Compressor 42 Desuperheater 45 Pressure Detector 46 Rotation Speed Controller 48 Water Injection Valve 49 Temperature Controller 50 Pressure Regulator Valve 51 Pressure Regulator 52 Pressure Regulator Valve 53 Pressure Regulator 54 Water Injection Valve 55 Desuperheater 56 Temperature Controller 57 Water Injection Valve 58 Temperature Controller

Claims (6)

[Claims] 1. A cogeneration steam turbine plant for co-supplying power and a process with steam of different pressure levels and temperatures, wherein steam of higher level pressure and temperature of said different levels is steamed up to lower level pressure. A steam compressor that expands in the turbine and that boosts the pressure-controlled extracted steam or exhaust steam; and pressure control means that controls the pressure of the steam sent from this steam compressor to the above-mentioned upper level pressure. A cogeneration steam turbine plant, characterized by being equipped with. 2. A cogeneration steam turbine plant according to claim 1, wherein the pressure control means detects a pressure of the steam sent from the steam compressor to the process, and a pressure detected by the pressure detector. A cogeneration steam turbine plant, comprising: a control means for controlling the rotation speed of the steam compressor based on a deviation from a target value of the pressure with respect to an upper level. 3. The cogeneration steam turbine plant according to claim 1, wherein the pressure control means detects a pressure of steam sent from the steam compressor to the process, and a discharge side or a suction side of the steam compressor. And a control means for controlling the pressure adjustment valve provided on the discharge side or the suction side from the deviation between the pressure detected by the pressure detector and the target value of the upper level pressure. A cogeneration steam turbine plant that features. 4. The cogeneration steam turbine plant according to claim 1, 2 or 3, wherein temperature control means for controlling the temperature of the steam sent from the steam compressor to the process at the upper level temperature is added. A cogeneration steam turbine plant that features. 5. A cogeneration steam turbine plant according to claim 4, wherein the temperature control means is provided on a temperature detector for detecting the temperature of the steam sent from the steam compressor to the process, and on the suction side of the steam compressor. A cogeneration steam turbine, comprising: a water injection desuperheater; and a control means for controlling the water injection amount of the water injection desuperheater based on the deviation between the temperature detected by the temperature detector and the target value of the upper level temperature. plant. 6. A cogeneration steam turbine plant according to claim 4, wherein the temperature control means is a temperature detector for detecting the temperature of the steam sent from the steam compressor, and a first temperature sensor is provided on the suction side of the steam compressor. From the deviation between the temperature detected by the temperature detector and the target value of the upper level temperature, and the second water injection desuperheater provided on at least one of the discharge side and the vapor compression intermediate stage. A cogeneration steam turbine plant, comprising: a first and a second control means for controlling a water injection amount of a water injection desuperheater.