KR101612227B1 - Generation system using waste pressurte and waste heat, generation method thereof - Google Patents

Abstract

The present invention relates to a system and a method for generating power using waste pressure and waste heat which use waste pressure and waste heat used by a system to generate power, supply the waste pressure used for generating power to be used by a second system, and control a flow path of the waste heat and water pressure according to a use condition of steam discharged from an exit side of a turbine to generate power. According to the present invention, the system for generating power using waste pressure and waste heat comprises: a boiler to heat circulation water to generate steam; a first steam header to distribute the steam generated by the boiler to a first steam system; a reducing valve to reduce the pressure of the steam discharged from the first steam header to supply the steam; a second steam header connected to the rear end of the reducing valve to distribute the steam to a second steam system by opening and closing a first valve; a condenser connected to the rear end of the reducing valve to absorb heat from the steam by opening and closing a second valve to convert the steam into circulation water; a turbine to use waste heat and waste pressure of the steam discharged from the first steam header to generate rotational power; a generator to use the rotational power of the turbine to generate electricity; a third valve to regulate the steam supplied to the turbine; a fourth valve to supply either the steam discharged from the turbine or the steam discharged from the reducing valve to one system selected among the second steam header and the condenser; and a control unit to control the first to the fourth valve according to whether the second steam system operates and whether the turbine operates normally.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation system using waste pressure / waste heat,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation system and method using waste heat and pressure, and more particularly, to a power generation system using waste heat and a waste pressure used in a system, The present invention relates to a power generation system using pulsed pressure / waste heat and a method for controlling the flow path of waste heat and waste pressure according to the usage pattern of steam discharged from the turbine outlet side.

Generally, in an industrial plant, a primary steam heated by a boiler is introduced into the system, and a part of the steam thus generated is converted into an auxiliary steam to be used as a power of a rotating machine, or to be used for preheating or preheating the equipment.

As described above, there are two methods of extracting and using the steam required for the industrial plant from the boiler. The method of supplying the extracted steam after lowering the pressure and the temperature to the required level for each position required on the spot without separate equipment, In case of separate system separation using the produced steam, a method of regenerating and supplying the auxiliary steam by installing a steam exchanger, which is a heat exchanger, is adopted.

In this conventional configuration, heat loss is generated in the process of lowering the pressure and the temperature to the required level of the steam pressurized by the boiler.

That is, the steam pressurized by the boiler must lower the required pressure and temperature by using a decompression device (for example, a decompression valve or the like), and the decompression device is structured by simply increasing the volume of the steam , The noise is generated in the process of decompressing the high-pressure steam. Further, when the high-pressure steam is decompressed to the medium pressure or the low pressure during the depressurization, the energy corresponding to the difference in pressure is consumed without any work.

Therefore, efforts have been made to recover energy that is naturally discharged (abandoned) while the high-pressure steam is changed to low pressure. However, most of the turbines used in such a system convert the linear motion into the rotary motion Piston type turbines are used. In the piston type engine, the engine efficiency is lowered due to the vibration due to the linear reciprocating motion, the loss in the process of converting the linear reciprocating motion into the rotational kinetic energy, and the loss due to the weight of the piston and the rocker arm. There is a problem that it is difficult to control the suction / discharge, and the pressure of the steam must be considerably high, and the pressure of the secondary side of the turbine can not be arbitrarily adjusted.

On the other hand, in order to solve some of these problems, Patent Publication No. 10-0779692 discloses a power generation plant having a power generation facility for recovering power from a steam pressure reduction system.

The above-mentioned technique is a method of controlling a steam turbine, including a pulsation-pressure-backpressure-type reduced-pressure steam turbine that produces a shafting force by expanding the pressure upstream and downstream of a steam pressure converter to a pressure required by a steam converter, Generator and a secondary pressure reducing valve for controlling the flow rate and temperature / pressure of the secondary pressure-reducing steam turbine and for controlling the energy required for the steam converter.

However, the above-mentioned technology has a disadvantage in that it is supplied to the system by the pressure reducing valve in case of waste heat, and is difficult to use because it is a system that generates electricity using only the waste pressure.

In addition, there is a problem that the generation system can not be controlled according to abnormal operation of the back pressure type steam turbine.

KR 10-0779692 B1 Nov. 20, 2007.

Disclosure of Invention Technical Problem [8] The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a turbine capable of utilizing both waste heat and waste pressure, System and method therefor.

Another problem to be solved by the present invention is to provide a power generation system and method using waste pressure / waste heat that can control the steam circulation system of a power generation system depending on whether the turbine is abnormal or whether the steam is used in the field.

According to an aspect of the present invention, there is provided a power generation system using waste pressure / waste heat, comprising: a boiler for heating circulation water to generate steam; A first steam header for distributing steam generated in the boiler to a first steam system; A pressure reducing valve for reducing the pressure of the steam discharged from the first steam header; A second steam header connected to a downstream end of the pressure reducing valve and distributing the steam to the second steam system according to opening and closing of the first valve; A condenser connected to a downstream end of the pressure reducing valve for absorbing heat from the steam according to opening and closing of the second valve and converting the heat into circulating water; A turbine generating rotational power using waste heat and waste pressure of steam discharged from the first steam header; A generator for generating electricity using rotational power of the turbine; A third valve for controlling the steam supplied to the turbine; A fourth valve for supplying steam selected from the steam discharged from the turbine or the steam discharged from the pressure reducing valve to the one selected from the second vapor header or the condenser; And a controller for controlling the first to fourth valves according to the operation of the second steam system and the normal operation of the turbine.

Wherein the controller is configured to: a) detect the operation of the second vapor header and, when a signal according to the operation is detected, control the decompression valve and the first to fourth valves to supply the steam to the second vapor header B) detecting whether or not the second steam header is operating, and controlling the pressure reducing valve and the first to fourth valves to be supplied to the condenser when a signal corresponding to the stop is detected .

The control unit detects whether the turbine is operating normally, and when the detected signal is determined to be a failure of the turbine, the control unit opens the pressure reducing valve to be supplied to the second vapor header or the condenser through the pressure reducing valve And a control unit.

In order to solve the above-described problems, a method for generating electricity using waste pressure / waste heat according to the present invention includes a second steam header operation detection step (S10) for detecting whether the second steam header is operated or not; A first valve opening step (S20) of opening the first valve when it is determined that the second vapor header is activated as a result of detection of the operation of the second vapor header; A second valve blocking step (S30) for blocking the second valve after opening the first valve; A turbine normal operation detecting step (S40) of detecting the normal operation of the turbine after shutting off the second valve; A fourth valve control step of controlling the fourth valve to control the steam discharged from the turbine to be transferred to the first valve and the second valve when the normal operation of the turbine is detected as a normal operation of the turbine S50); A third valve opening step (S60) of opening the third valve after controlling the fourth valve; And closing the pressure reducing valve (S70) after the third valve is opened.

According to the present invention, as the waste heat and the waste pressure discharged from the first steam header are supplied to the second steam header while the high pressure steam is changed to the low pressure through the turbine, the steam pressure required in the second steam header is reduced, So that the high-pressure steam is changed to a low-pressure steam, and the steam is discarded, thereby recovering energy that is consumed in a meaningless manner, thereby producing electricity.

Further, since it is possible to control the supply of the steam appropriately according to whether the second steam header is operated and whether the turbine is normally operated, there is an advantage that failure due to reverse flow of the system can be minimized.

In addition, since the electric power can be produced by the waste heat and the waste pressure which are prevented by using the turbine which can use both the steam heat and the steam pressure, there is an advantage that the energy produced by the boiler can be utilized to the maximum.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a power generation system using waste heat and waste pressure according to the present invention; FIG.
2 is a view showing a flow of steam supply by control of a fourth valve in a power generation system using waste heat and waste pressure according to the present invention.
3 is a view schematically showing a configuration of a control unit in a power generation system using waste heat and waste pressure according to the present invention.
4 is a flowchart of a power generation method using waste heat and waste pressure according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

According to the present invention, it is possible to supply the waste pressure generated in the power generation system using the waste heat and the waste pressure used in the system so that the waste pressure used for the power generation can be used in the second system, The present invention relates to a power generation system using waste pressure / waste heat and a method thereof, which can generate power by controlling a flow path of a waste pressure.

1 is a schematic diagram of a power generation system using waste heat and waste pressure according to the present invention.

1, a power generation system using waste heat and waste pressure according to the present invention includes a boiler 10, a first steam header 20, a pressure reducing valve 30, a second steam header 40, a condenser 50 A turbine 60, a generator 70, a pump 80 and a control unit 90. The control unit 90 includes a valve for supplying or shutting off steam to the system under the control of the control unit 90, do.

Here, the valve may include a first valve 110, a second valve 120, a third valve 130, and a fourth valve 140.

The boiler 10 is a device for generating steam by heating a circulating fluid (circulating water). The boiler 10 heats the circulating fluid by consuming fuel, and outputs the steam generated by heating.

At this time, the steam pressure output from the boiler 10 is about 5 to 20 kg / cm 2 g for the small steam system and 100 to 200 kg / cm 2 g or more for the large steam system. Such high pressure steam is a great pressure to be used as it is in the industrial field. Accordingly, although the steam output from the boiler 10 is not shown in the drawing, the steam may be supplied to the steam pressure reducing valve.

According to the present invention, when the pressure of the steam output from the boiler 10 is maintained at a predetermined level or more, it can be used not only in a small steam system but also in a large steam system.

The first steam header 20 is a device for introducing the steam output from the boiler 10 and distributing the steam to the first steam system of the industrial site.

The pressure reducing valve 30 is a device for reducing the pressure of the steam to be used in the second steam system. The pressure of the steam output from the first steam header 20 is 10 kg / cm2g and the pressure of the steam is converted to 3 kg / cm2g which is usable in the second steam system .

The second steam header 40 is connected to a downstream end of the pressure reducing valve 30 and distributes the steam to the second steam system according to the opening and closing of the first valve 110.

The condenser 50 is connected to the downstream end of the pressure reducing valve 30 to absorb heat from the steam in accordance with the opening and closing of the second valve 120 and convert it into circulating water.

At this time, the steam discharged from the pressure reducing valve 30 is diverged, and the first valve 110 and the second valve 120 are installed in the diverged flow paths, and the first valve 110 and the second valve 120, A first steam header 40 is installed and a condenser 50 is installed at a rear end of the second valve 120.

The turbine 60 is for generating electricity by recovering energy that is naturally discharged (abandoned) while the high-pressure steam is changed to low pressure in the pressure reducing valve 30, and the first steam header 20, And the waste heat of the steam discharged from the steam generator is used to generate rotational power.

That is, as shown in FIG. 1, the turbine 60 is installed in a steam line branched from an output path of the first steam header 20, and the steam output from the turbine 60 is supplied to the steam- And is connected to the rear end of the valve 30 to discharge the steam.

At this time, the turbine 60 is composed of a turbine that can use both the steam pressure and the steam heat.

Generally, a turbine includes a housing, a shaft rotatably configured within the housing, a rotor coupled to the shaft and rotated by contacting a steam pressure or a steam heat with the blade, The rotor is rotated, and the shaft coupled to the rotor is rotated.

In the case of a turbine using steam pressure, the steam that drives the turbine maintains a predetermined pressure. For example, when a steam pressure of 10 kg / cm 2 g is supplied to the turbine, the shaft of the turbine is rotated and the pressure of the discharged steam is converted to a steam pressure of about 3 kg / cm 2 g. However, in the case of a turbine driven by a low-pressure low-temperature steam or an auxiliary steam, the supplied steam rotates the shaft of the turbine, and the discharged steam is converted into a saturated steam state and converted into moisture at low temperature. Accordingly, the blade, the rotor and the housing may be made of a material having corrosion resistance against steam pressure and steam heat so that both the steam pressure and the steam heat can be used.

A third valve 130 and a fourth valve 140 for controlling the supply of steam to the turbine 60 are installed at the front and rear ends of the turbine 60 and the fourth valve 140 and the turbine 60, And a check valve 150 for preventing the back flow of the steam.

The third valve 130 may be a three-port three-way valve for supplying steam selectively to the pressure reducing valve 30 or the turbine 60.

The fourth valve 140 may supply one steam selected from the steam discharged from the turbine 60 or the steam discharged from the pressure reducing valve 30 to the second vapor header 40 and the condenser 50, Way three-way valve to provide steam to the steam turbine.

2 is a view showing the flow of steam supply by the control of the fourth valve in the power generation system using the waste heat and the waste pressure according to the present invention.

Referring to FIG. 2, the fourth valve 140 is rotated by control to allow the steam discharged from the pressure reducing valve 30 to be transferred to the second vapor header 40 and the condenser 50 And a power generation system control (b) for transmitting the steam discharged from the turbine (60) to the second steam header (40) and the condenser (50).

That is, the decompression system control is used when abnormality is detected in the turbine 60, and controls the steam to be transferred to the second steam header 40 or the condenser 50 through the pressure reducing valve 30, The system control is performed so that the steam is transferred to the second steam header 40 or the condenser 50 through the turbine 60 on the assumption that the turbine 60 is operated normally.

Accordingly, one steam selected from the steam discharged from the turbine 60 or the steam discharged from the pressure reducing valve 30 according to the rotational direction of the fourth valve 140 flows into the second steam header 40, And is supplied to the condenser 50.

The generator 70 is a device for generating electricity by receiving the rotational force of the shaft of the turbine 60. The generated electricity may be used in a power generation system using waste pressure / waste heat according to the present invention or may be configured to be supplied to the outside have.

The pump 80 is for pumping the circulating water condensed in the condenser 50 and stored in the plurality of tanks 55 to be transferred to the water supply tank 15 used in the boiler 10.

The control unit 90 controls the pressure reducing valve 30 and the first to fourth valves according to whether the second steam header 40 is operating or not and whether the turbine 60 is operating normally. 3 is a view schematically showing a configuration of a control unit in a power generation system using waste heat and waste pressure according to the present invention.

3, the control unit 90 detects whether the second steam header 40 is operating and whether the turbine 60 is operating normally. The control unit 90 controls the pressure reducing valve 30, the first valve 110, The second valve 120, the third valve 130 and the fourth valve 140, as shown in FIG.

The operation of the second steam header 40 may be detected by detecting the operation of the valve connected to the second steam header 40 or the steam flow of the flow pipe, Can be configured to be detected by sensing whether the shaft is rotating or not.

The process of controlling the pressure reducing valve 30 and the first to fourth valves according to whether the controller 90 configured as described above operates the second steam header 40 and whether the turbine 60 operates normally Explain.

First, the controller 90 detects whether the second steam header 40 is operated, and when a signal corresponding to the operation is detected, the control unit 90 controls the pressure reducing valve and the first to fourth valves, 30 or the steam discharged from the turbine 60 is supplied to the second steam header 40.

The control unit 90 detects whether the second steam header 40 is operated and controls the pressure reducing valve 40 and the first to fourth valves when a signal corresponding to the stop is detected, So that the steam discharged from the pressure reducing valve (30) or the turbine (60) is supplied to the condenser (50).

Whether the steam discharged from the first steam header 20 is transferred through the pressure reducing valve 30 or transferred through the turbine 60 is determined according to the normal operation of the turbine 60 .

That is, the controller 90 detects the normal operation of the turbine 60, and when the detected signal is determined as a failure of the turbine 60, the pressure reducing valve 30 is opened, To the second vapor header (40) or the condenser (50) through the valve (30). The control unit 90 detects whether the turbine 60 is operating normally and cuts off the pressure reducing valve 30 when the detected signal is determined to be normal to the turbine 60, (40) or the condenser (50) through the first steam header (60).

According to the present invention, as the waste heat and the waste pressure discharged from the first steam header are supplied to the second steam header while the high pressure steam is changed to low pressure through the turbine, the steam pressure required in the second steam header, And it is advantageous in that the high-pressure steam is changed to low pressure and the energy that is naturally discharged (abandoned) is consumed through the turbine to produce electricity.

Further, since it is possible to control the supply of the steam appropriately according to whether the second steam header is operated and whether the turbine is normally operated, there is an advantage that failure due to reverse flow of the system can be minimized.

Next, a power generation method using the waste heat and the waste pressure according to the present invention will be described.

4 is a flowchart of a power generation method using waste heat and waste pressure according to the present invention.

Referring to FIG. 4, the method of generating power using waste heat and waste pressure according to the present invention includes a second steam header operation detection step S10, a first valve opening step S20, a second valve blocking step S30, A turbine normal operation detection step S40, a fourth valve control step S50, a third valve opening step S60, and a reducing valve shutoff step S70.

1. Detecting whether the second steam header is operated (S10)

The second steam header operation detection step S10 is a step of determining whether the steam is supplied to the second steam system or the steam is supplied to the controller 90 through the second steam header 40. [

2. In the first valve opening step (S20)

The first valve opening step S20 is a step of opening the second steam header 40 so that the steam can be transferred to the second steam header 40 when the second steam header 40 needs to supply steam to the second steam system. The first valve 110 provided at the front end of the header 40 is opened.

That is, the controller 90 controls the first valve to be opened when it is determined that the second steam header is activated as a result of detection of the operation of the second steam header.

3. In the second valve blocking step (S30)

The second valve blocking step S30 is a process of blocking the second valve 120 according to the first valve opening step S20 to prevent the steam from flowing into the condenser 50. [

At this time, the opening of the first valve according to the first valve opening step (S20) and the closing of the second valve according to the second valve closing step (S30) may be performed sequentially or simultaneously. Also, the first valve 110 and the second valve 120 may be interlocked to open at least one valve.

Here, the interlock connection means a connection configuration in which at least two valves are simultaneously closed so that the flow path is not closed or opened at the same time.

4. Turbine normal operation detection step (S40)

The turbine normal operation detecting step S40 is a step of detecting whether the normal operation of the turbine 60 is being performed after the second valve 120 is shut off.

At this time, the turbine 60 may be configured to supply steam to the turbine 60 for a predetermined time to confirm normal operation of the turbine 60. For example, the third valve 130 may be opened for a predetermined time and the fourth valve 140 may be controlled so that the steam discharged from the first steam header 20 flows through the turbine 60 The operation of the turbine 60 is determined to be a normal operation only when the operation of the turbine 60 operates within a predetermined range within a normal range.

5. In the fourth valve control step (S50)

When the operation of the turbine 60 is detected as a normal operation, the fourth valve control step S50 controls the fourth valve so that the steam discharged from the turbine 60 flows into the first valve 2 valve.

6. Third valve opening step (S60)

The third valve opening step S60 is a step of opening the third valve after controlling the fourth valve. The steam discharged from the first steam header 20 flows through the third valve 130 and the turbine 60 through the fourth valve 140 to the second steam header 40, .

7. Decompression valve shutoff step (S70)

The reducing valve shutoff step S70 may be performed after the third valve 130 is opened according to the third valve opening step S60 or when the third valve 130 is opened, .

The fourth valve 140 closes the downstream end of the pressure reducing valve 30 according to the fourth valve control step S50 and does not need to shut down the pressure reducing valve 30, The predetermined amount of steam discharged from the first steam header 20 flows into the pressure reducing valve 30 to prevent an accident caused by the steam pressure.

The turbine 60 may be configured to supply steam to the turbine 60 for a predetermined period of time in order to confirm a normal operation of the turbine 60 in the turbine normal operation detection step S40. The fourth valve control step S50, the third valve opening step S60 and the pressure reducing valve blocking step S70 may be configured to maintain the state.

A description will be given of a case where the second steam header is determined to be stopped or the turbine is detected as an abnormal operation as a result of the operation detection of the turbine.

Referring to FIG. 4, when it is determined that the second steam header 40 is stopped as a result of detection of the operation of the second steam header 40, the controller 90 controls the second valve 120 (S25) and the first valve (110) is closed (S35) so that the steam is transferred to the side of the condenser (50).

When the turbine is detected as an abnormal operation as a result of the operation detection of the turbine, the controller 90 controls the fourth valve 140 (S55) to allow the steam to flow in from the pressure reducing valve 30, The pressure reducing valve 30 is opened (S75) while the valve 130 is closed (S65), so that the steam discharged from the steam header 20 is passed through the pressure reducing valve 30.

According to the present invention, it is possible to control the supply of steam appropriately according to the operation of the second steam header and the normal operation of the turbine. Therefore, it is possible to minimize the failure due to the reverse flow of the system, There is an advantage to be able to produce.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

10: boiler 15: water tank
20: first steam header 30: pressure reducing valve
40: second steam header 50: condenser
55: multiple tanks 60: turbine
70: generator 80: pump
90: control unit 110: first valve
120: second valve 130: third valve
140: fourth valve 150: check valve

Claims (4)

A boiler for heating the circulating water to generate steam;
A first steam header for distributing steam generated in the boiler to a first steam system;
A pressure reducing valve for reducing the pressure of the steam discharged from the first steam header;
A second steam header connected to a downstream end of the pressure reducing valve and distributing the steam to the second steam system according to opening and closing of the first valve;
A condenser connected to a downstream end of the pressure reducing valve for absorbing heat from the steam according to opening and closing of the second valve and converting the heat into circulating water;
A turbine generating rotational power using waste heat and waste pressure of steam discharged from the first steam header;
A generator for generating electricity using rotational power of the turbine;
A third valve for controlling the steam supplied to the turbine;
A fourth valve for supplying one steam selected from the steam discharged from the turbine or the steam discharged from the pressure reducing valve to the second steam header and the condenser; And
A control unit for controlling the pressure reducing valve and the first to fourth valves according to whether the second steam header is operating and whether the turbine operates normally;
And a power generation system using the waste pressure / waste heat.
The method according to claim 1,
Wherein,
a) detecting whether the second steam header is operating, and controlling the steam to be supplied to the second steam header by controlling the pressure reducing valve and the first to fourth valves when a signal according to the operation is detected,
b) detecting whether or not the second vapor header is operating, and controlling the decompression valve and the first to fourth valves to supply steam to the condenser when a signal corresponding to the stop is detected. Power generation system using waste heat.
The method according to claim 1,
Wherein,
And the control unit controls the second steam header or the condenser to supply the steam to the second steam header or the condenser through the pressure reducing valve by opening the pressure reducing valve when the detected signal is a failure of the turbine Power generation system using waste pressure / waste heat.
A power generation method using waste pressure / waste heat using a power generation system using waste pressure / waste heat according to any one of claims 1 to 3,
A second steam header operation detection step (S10) for detecting whether the second steam header is in operation;
A first valve opening step (S20) of opening the first valve when it is determined that the second vapor header is activated as a result of detection of the operation of the second vapor header;
A second valve blocking step (S30) for blocking the second valve after opening the first valve;
A turbine normal operation detecting step (S40) of detecting the normal operation of the turbine after shutting off the second valve;
A fourth valve control step (S50) for controlling the fourth valve to control the steam discharged from the turbine to be transferred to the first valve and the second valve when the turbine is detected as a normal operation, ;
A third valve opening step (S60) of opening the third valve after controlling the fourth valve; And
A pressure reducing valve shutoff step (S70) for shutting down the pressure reducing valve after opening the third valve;
And a power generation unit for generating power by using the waste pressure / waste heat.

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