JPS6349523Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combined heat and power generation facility equipped with an air-fuel mixture back pressure turbine that extracts a portion of turbine steam and uses it as process steam.

Cogeneration power generation uses steam generated from a boiler to rotate a turbine to generate electricity, and a portion of the turbine steam is extracted to produce process steam for use in factories and the like.

Figure 1 shows an example of the configuration of a conventional combined heat and power generation facility, which includes a boiler 1 that generates high-pressure and high-temperature steam, a main steam pipe 2 that supplies the steam generated in the boiler 1 to a load, and a high-pressure turbine 3 that receives main steam supplied from a main steam pipe 2 and converts the steam energy into rotational energy; a reheater 4 that heats the steam discharged from the high-pressure turbine 3;
An intermediate pressure turbine 5 is connected coaxially with the high pressure turbine 3 and receives steam supplied from the reheater 4 and converts the steam energy into rotational energy; and an intermediate pressure turbine 5 is connected coaxially with the intermediate pressure turbine 5 and is discharged from the intermediate pressure turbine 5. A low-pressure turbine 6 receives supplied steam and converts the steam energy into rotational energy, a generator 7 rotates by the turbine and generates the required electric power, and a generator 7 that cools and condenses the steam discharged from the low-pressure turbine 6. A condenser 8 that will later be supplied to the boiler 1,
A back pressure turbine 11 to which a portion of turbine steam is supplied via a process steam supply line 10 from a low temperature reheat pipe 9 connecting a high pressure turbine 3 and a reheater 4, and power generation driven by the back pressure turbine 11. Machine 12
, an exhaust line 13 to which the exhaust gas output from the back pressure turbine 11 is supplied, a pressure detector 14 that detects the exhaust pressure of the exhaust line 13, and a steam regulator that adjusts the amount of steam supplied to the back pressure turbine 11. Valve 1
5, a control device 16 that controls the steam control valve 15 according to the detection level of the pressure detector 14, a flow control valve 17 that is connected to the exhaust line 13 and controls the flow rate of passing steam, and the flow control valve 17. The flow rate detector 18 is installed on the outlet side of the flow rate detector 18 to detect the passing flow rate, and the flow rate adjustment setting device 19 controls the flow rate control valve 17 according to the detection level of the flow rate detector 18.

In the above configuration, high-pressure, high-temperature steam generated in the boiler 1 is sent to the high-pressure turbine 3 via the main steam pipe 2 and is consumed as rotational energy, which is recovered as electric power by rotating the generator 7, and then transferred to the reheater. After being sent to the intermediate pressure turbine 5, it is sent to the intermediate pressure turbine 5. The steam consumed as rotational energy in the intermediate pressure turbine 5 is further consumed in the low pressure turbine 6 and recovered as electricity, and then the entire amount is sent to the condenser 8, where it is cooled and turned into water, and then sent to the boiler 1. be returned. This water is sent to boiler 1 again, and the above-mentioned process is repeated thereafter. In addition, in order to compensate for the shortage of process steam consumed in factories and the like, a portion of the steam discharged from the high-pressure turbine 3 is introduced into the back-pressure turbine 11, and the steam used in this turbine is supplied as process steam. The reason why process steam is generated through the back pressure turbine 11 in this way is, for example, at a temperature of about 35Kg/cm ² and a temperature of 350°C.
The factory process steam set pressure is approximately 13
When reducing pressure and temperature to a level of 220℃ at Kg/ ^cm2 , using a pressure regulating valve or water injection device results in energy loss and cannot be recovered, so a back pressure turbine is installed to recover it as electricity and then supply it as process steam. It is something to do.

However, in the combined heat and power generation equipment as shown in FIG. 1, the steam pressure in the low temperature reheat pipe 9 changes depending on the output of the high pressure turbine 3, as shown in FIG. 2, the turbine output changes. Such changes in turbine output cause fluctuations in the conditions of the inlet steam of the back pressure turbine 11. Therefore, in order to be able to follow these fluctuations, it is necessary to provide one back pressure turbine for each power generation unit consisting of the system from the boiler 1 to the reheater 4. For this reason, usually a plurality of power generation units are provided (that is, a plurality of turbines each consisting of the back pressure turbine 3 to the low pressure turbine 6 are provided), but the steam pressure extracted from each power generation unit is are often different.
Therefore, it is necessary to install a back pressure turbine with a capacity corresponding to each steam pressure each time, which has the disadvantage of increasing equipment costs. Moreover, the process steam supplied from the back pressure turbine 11 changes due to fluctuations in supply and demand, so the amount of steam generated has tended to increase in recent years due to the installation of waste heat boilers, etc. However, when the process steam becomes excessive, the power generation unit There is a problem in that providing a back pressure turbine for each of the two systems is undesirable because it leads to a decrease in the utilization rate.

An object of the present invention is to provide a cogeneration power generation facility equipped with an air-fuel mixture backpressure turbine whose equipment configuration is simplified by allowing a single backpressure turbine to serve a plurality of power generation units.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Fig. 3 shows one embodiment of the present invention. Components that are the same as those shown in Fig. pressure control valves 31 and 32 inserted between the low-pressure chambers of the back-pressure turbine 11 and the low-pressure reheat pipes 9 and 9' of the power generation units A and B of the power generation units ' and a high pressure chamber of the back pressure turbine 11, a pressure gauge 35 that measures the steam pressure in the low temperature reheat pipe 9, and a pressure gauge 35 that measures the steam pressure in the low temperature reheat pipe 9'. A pressure gauge 36 to be measured, a differential pressure transmitter 37 that outputs a control command based on a level difference between detection outputs of the pressure gauges 35 and 36, and the differential pressure transmitter 3.
7 and a control device 38 that controls each of the pressure control valves 31, 32, 33 and 34 based on the output of the pressure detector 14, which differs from the structure shown in FIG.

In the above configuration, the pressure gauges 35 and 36 constantly monitor the steam pressure in the low-temperature reheating tubes 9 and 9', and the differential pressure between them is calculated by the differential pressure transmitter 37. Based on this differential pressure value, the detected value of the pressure detector 14, and the value set in the device as the process steam pressure, the control device 38 controls the pressure control valves 33, 34 so that the process steam set pressure in the exhaust line 13 is reached. ,35,3
6.

The amount of process steam supplied from the exhaust line 13 is set in the flow rate adjustment setting device 19. The flow rate adjustment setting device 19 controls the control valve 17 so that the detected value of the flow rate detector 18 matches this set value, and the set flow rate is caused to flow. However, as the pressure in the exhaust line 13 changes at this time, the control device 38 controls the pressure control valves 33 to 36 to maintain this pressure change at the set pressure, thereby controlling the steam pressure according to each steam pressure. quantity is supplied to the air-fuel mixture backpressure turbine.

For example, if the output signal from the differential pressure transmitter 37 indicates that the steam pressure on the power generation unit A side is higher than the steam pressure on the power generation unit B side, the control device 38 will Pressure control valve 33
is set in the open direction, and the pressure control valve 31 is controlled to be fully open, so that steam from the power generation unit A side, which has a higher pressure, is preferentially supplied to the high pressure chamber of the back pressure turbine 11.
On the other hand, for the steam from the power generation unit B side where the pressure is low, the pressure control valve 34 is fully closed and the pressure control valve 32 is controlled in the open direction, and the low pressure chamber of the back pressure turbine 11 is supplied from the power generation unit B side. Introduce steam.

In the opposite situation to the above, that is, when the steam pressure on the power generation unit A side is lower than the steam pressure on the B side,
The pressure control valve 34 is set in the open direction and the pressure control valve 32 is controlled to be fully closed, so that the high-pressure power generation unit B
The side steam is preferentially supplied to the low pressure chamber of the back pressure turbine 11. On the other hand, the steam from the power generation unit A side with lower pressure is transferred to the back pressure turbine by fully closing the pressure control valve 33 and controlling the pressure control valve 31 in the opening direction.
Steam from the power generation unit A side is introduced into the high pressure chamber No. 1.

As mentioned above, even if there are multiple power generation units with different steam pressures, the equipment can be simplified and the equipment cost can be minimized by appropriately supplying extraction turbine steam to a single air-fuel mixture back pressure turbine. Electricity can be recovered. In this invention, high, medium,
Even if there are multiple pressure levels such as low pressure, this can be accommodated by simply increasing the number of piping and pressure control valves.

In addition, in the above embodiment, the case where there is a difference in the steam pressure of each power generation unit,
Even if the respective vapor pressures are the same, the exhaust line 13
Pressure control valves 33, 3 so that the pressure of
4 in the open direction, and the pressure control valves 31, 32
This can be similarly carried out by controlling in the closing direction.

The inventor attempted to implement the system using equipment with the configuration shown in Figure 3 and having the following steam supply capacity.

Overall process steam supply capacity 80t/h Steam supply capacity of each power generation unit A and B
40t/h As shown in Figure 4, the output of power generation unit A is 90% of the rated output, and as shown in Figure 5, power generation unit B
While operating with side output at 65%, exhaust line 1
The process steam supply amount of the flow rate adjustment setting device 15 in No. 3 was set to 60 t/h, and the steam pressure was set to 13 Kg/cm ² .
At this time, the pressure control valve 33 is fully opened, the pressure control valves 31 and 34 are fully closed, and the pressure control valve 32 is fully closed.
was controlled to be 45% open, and the exhaust pressure of the air-fuel mixture back pressure turbine of the pressure detector 14 in the exhaust line 13 was controlled to be constant at 13 kg/cm ² . In this case, power generation unit A has a low temperature reheat pipe pressure of 32
kg/cm ² and the temperature is 350°C, and in power generation unit B, the low temperature reheat tube pressure is 24 kg/cm ² and the temperature is 300°C, even though there is a differential pressure of 8 kg/cm ² between both units. First, it was confirmed that process steam could be supplied while keeping the process steam pressure in the exhaust line 13 constant at a set pressure of 13 kg/cm ² .

As is clear from the above, according to the present invention, one back pressure turbine and the low-temperature reheat pipes of a plurality of power generation units are individually connected via pressure control valves, and the differential pressure between the power generation units and the By controlling based on the exhaust pressure of the back pressure turbine, a single back pressure turbine can supply process steam at a constant pressure to multiple power generation units, eliminating the need to use a back pressure turbine for each unit. It is possible to reduce costs.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an example of a conventional combined heat and power generation facility, Fig. 2 is a steam turbine output characteristic diagram for the equipment shown in Fig. 1, Fig. 3 is a system diagram showing an example of the present invention, and Fig. 4 is a system diagram showing an example of a conventional combined heat and power generation facility. The figure is a steam turbine output characteristic diagram of power generation unit A in one embodiment of the present invention, and FIG. 5 is the output characteristic diagram of the steam turbine of power generation unit B in one embodiment of the present invention. 1... Boiler, 3, 3'... High pressure turbine, 9,
9'... Low temperature reheat pipe, 10, 10'... Process steam supply line, 11... Back pressure turbine, 13...
Exhaust line, 14...Pressure detector, 17...Flow rate control valve, 18...Flow rate detector, 19...Flow rate adjustment setting device, 31, 32, 33, 34...Pressure control valve, 35, 36... Pressure gauge, 37... Differential pressure transmitter, 38... Control device.

Claims (1)

[Scope of utility model registration request] In a cogeneration power generation facility in which a plurality of generators are driven by a plurality of turbines supplied with high-pressure steam from a steam generation source, and turbine steam extracted from the turbines is utilized as process steam, the turbine steam supplied with the extracted turbine steam is supplied. a back pressure turbine that drives a generator and uses exhaust steam as process steam, and a system between each of the extraction ports provided in each of the plurality of turbines and the steam intake of the back pressure turbine. a pressure control valve that is individually provided in the passage; and a control unit that adjusts the opening degree of each pressure control valve based on the differential pressure between the turbine steam extracted for each turbine and the set pressure of the process steam. A combined heat and power generation facility equipped with an air-fuel mixture back pressure turbine.