JP5967652B2 - Operation method of municipal waste incineration plant with steam turbine generator and arithmetic controller for adjusting steam pressure at the inlet of the steam turbine used therefor - Google Patents

Description

The present invention relates to an operation method of a municipal waste incineration plant equipped with a steam turbine power generator and an improvement of a calculation controller for adjusting the steam pressure at the turbine inlet used for the operation, and a municipal waste incinerator equipped with a waste heat recovery boiler. By linking the automatic combustion control system with the pre-pressure control system for the steam pressure at the inlet of the turbine, and adjusting the pre-pressure (inlet-side steam pressure) of the turbine based on the amount of steam vaporization of the boiler by the automatic combustion control system, Even if the quality etc. fluctuates, the steam pressure at the outlet of the boiler's steam superheater is kept constant, which ensures high power generation efficiency and maximum power generation throughout the year, regardless of the load conditions during operation of the municipal waste incineration plant. The present invention relates to a method for operating a municipal waste incineration plant with a steam turbine power generation device and a calculation controller for adjusting steam pressure at the inlet of a steam turbine used therefor. It is intended.

  Conventionally, in municipal waste incineration plants, heat energy generated from waste incineration is recovered by a boiler or economizer, and steam generated by the recovered heat is used to drive a turbine generator to generate electricity. It is. In particular, due to changes in the power supply situation in recent years, even small-scale municipal waste incineration plants have been required to generate waste by using waste heat recovery. Furthermore, regardless of the size of the waste incineration plant, the waste heat recovery rate has been improved. In addition, there is a strong demand for improvements in power generation efficiency and annual total power generation.

  FIG. 4 shows an example of a steam system of a steam turbine power generator installed in a conventional municipal waste incineration plant. Steam generated in the waste heat recovery boiler 1 is superheated with a steam superheater 2 and heated at a high temperature. By supplying high-pressure heated steam to the pre-pressure controlled steam turbine 4 through the main steam pipe 3, the generator 4a is rotationally driven.

  In FIG. 4, 5 is a condenser, 6 is a condensate tank, 7 is a deaerator feed pump, 8 is a deaerator 9 is a boiler feed pump, 10 is an economizer, 11 is a steam air preheater, 12 Is a heat utilization device, 13 is a water supply treatment device, 14 is a main steam control valve, and 15 and 16 are pressure detectors.

Further, the steam turbine 4 are generally the main steam control valve 14 by a turbine inlet steam pressure P ₂ a predetermined set pressure control type steam turbine ago so as to adjust the pressure of 4 is used (Patent Literature 1 etc.).
Note that the steam turbine power generator itself shown in FIG. 4 is well known, and a detailed description thereof is omitted here.

Thus, in order to perform high-efficiency power generation with the steam turbine generator, the steam at the inlet of the turbine adapted to the high temperature and high pressure of the steam from the waste heat recovery boiler 1, stabilization of the flow rate of the supplied steam, and the capacity of the steam turbine 4. Ensuring the pressure P ₂ is an essential requirement, and various techniques have been developed and put into practical use in order to meet these requirements.

  For example, regarding the high temperature and high pressure of steam, the problem of corrosion of the heat transfer tube of the steam superheater 2 due to the combustion exhaust gas of municipal waste is cleared, and the steam from the waste heat recovery boiler 1 is pressure 4.00MPa (G), temperature 400 A steam superheater 2 that can produce superheated steam at (° C.) or higher has been developed and put into practical use (Patent Document 2, Patent Document 3, etc.).

  Also, regarding the supply steam flow rate (steam evaporation amount), the municipal waste incineration plant is controlled by the automatic combustion device so that the combustion amount, that is, the steam evaporation amount of the boiler is controlled to be constant, thereby stabilizing the steam supply amount to the steam turbine 4. (Patent Document 4 etc.).

As a result, also in the conventional steam turbine power generation device of FIG. 4, when the waste quality supplied to the municipal waste incineration plant is substantially constant and the combustion state of the incinerator is stable, the waste heat The steam evaporation amount Q of the recovery boiler 1, the outlet steam pressure P ₁ of the steam superheater 2, the steam pressure loss ΔP in the main steam pipe 3, the turbine inlet steam pressure P _{2 of the} steam turbine 4, etc. are set in advance, respectively. It is adjusted controlled to a value, thereby, the steam turbine 4 will be highly efficient operation under a turbine inlet steam pressure P ₂ is set.

However, in the above-described conventional steam turbine power plant, sets generally, without the adjusting the turbine inlet steam pressure P ₂ by performing load control of the steam turbine 4 side, always constant turbine inlet steam pressure P ₂ The operation is performed in a state where the value is maintained, and as a result, the remaining steam total amount obtained by removing the process steam from the steam generated in the waste heat recovery boiler 1 is supplied to the steam turbine 4.
Therefore, for example, if the flow rate of steam flowing through the main steam pipeline 3 is reduced due to changes in the combustion state of municipal waste or changes in the quality of municipal waste, the steam pressure loss ΔP in the main steam pipeline 3 also decreases. Accordingly, the outlet steam pressure P ₁ of the steam superheater 2 inevitably decreases in order to keep the turbine inlet steam pressure P ₂ at a constant set value. That is, the outlet steam pressure P ₁ of the steam superheater 2 becomes a so-called pressure value due to the so-called steam generation amount (steam flow rate), and the outlet steam pressure P ₁ of the steam superheater 2 is reduced by the decrease of the steam evaporation amount Q. There is a problem that the power generation efficiency deteriorates due to a decrease in power generation.

In general, the planning and design of a municipal waste incineration plant with a steam turbine power generator is performed assuming three types of municipal waste: low quality waste, standard waste, and high quality waste. And the main steam piping 3 which connects between the steam superheater 2 and the steam turbine 4 is designed on the basis of the steam generation amount at the time of the incineration processing of the high quality waste in which the generated steam amount Q becomes the maximum. That is, the steam pressure loss ΔP in the main steam pipe passage 3 based on the reference vapor flow rate is determined, the turbine inlet steam pressure P ₂ of the steam turbine 4 is determined by the steam pressure loss ΔP based. When the turbine inlet steam pressure P _{2 of} the steam turbine 4 is determined in advance, the outlet steam pressure P ₁ of the steam superheater 2 is determined from the turbine inlet steam pressure P ₂ and the steam pressure loss ΔP. Sometimes.

When the waste quality is reduced during the operation of the municipal waste incineration plant, and the steam generation amount (steam flow rate) is reduced, the steam pressure loss ΔP in the main steam pipe line 3 is also reduced. However, turbine inlet steam pressure P ₂ of the steam turbine 4 is to be controlled to maintain a pressure value determined based on the Koshitsu dust, steam superheater 2 the outlet steam pressure P ₁ vapor pressure loss ΔP The amount of decrease is reduced by ΔPc.

Moreover, since the variation of the waste quality in the municipal waste incineration plant is large, it is necessary to set the steam generation amount according to the waste quality, and the operation cannot always be continued in a state where the steam generation amount Q is maximized.
Of course, when the waste quality changes and the steam generation amount decreases, the combustion amount of the waste is adjusted by the automatic combustion control device, and the steam generation amount is finally corrected to the set value. However, a response delay is inevitable in the automatic combustion control, and therefore, the state in which the amount of generated steam is reduced continues for a certain period of time.

For example, the standard design values for high-quality waste combustion are the steam pressure P ₁ = 4.00 MPa (G) at the steam superheater 2, the steam pressure loss ΔP = 0.20 MPa (G) at the main steam line 3, and the steam turbine 4 Turbine inlet steam pressure P ₂ = 3.80 MPa (G), and a city of control system that maintains the turbine inlet steam pressure P ₂ at a constant value (3.80 MPa (G)) regardless of the waste quality and the amount of waste combustion Assume that during the operation of the waste incineration plant, the waste quality changes from high-quality waste to the standard waste quality, the steam flow rate decreases, and the steam pressure loss ΔP decreases to ΔP = 0.15 MPa (G). Then, since the turbine inlet steam pressure P ₂ is controlled to a constant value P ₂ = 3.80 MPa (G), the outlet steam pressure P ₁ of the steam superheater 2 decreases from 4.00 MPa (G) to 3.95 MPa (G). Thus, the operation of the boiler steam superheater 2 (4.00 MPa (G)) is not performed sufficiently, and as a result, the power generation efficiency of the steam turbine power generator is reduced.
In an actual municipal waste incineration plant, the most treated waste throughout the year is standard waste, so the outlet steam pressure P ₁ of the steam superheater 2 is lower than the design value. It is normal.

Table 1 shows the steam pressure at the outlet steam pressure P ₁ of the steam superheater 2 and the steam at the main steam pipe line 3 when the waste quality changes when the turbine inlet steam pressure P ₂ is controlled to a constant value of 3.80 MPa (G). This shows the pressure loss ΔP.

In addition, the applicant of the present application first sets a municipal waste incineration plant with a steam turbine power generator as a plant equipped with a plurality of incinerators, and lowers the incineration load of the plurality of incinerators constituting the plant to increase the number of simultaneous operation days. By doing so, a plant operation method has been developed that makes it possible to increase the total amount of generated power annually, and this is disclosed (Patent Document 5).
Also in the municipal waste incineration plant with a steam turbine power generator described in Patent Document 5, the outlet steam pressure P ₁ of the steam superheater 2 of each municipal waste incinerator decreases due to a decrease in the amount of generated steam. As in the case of a municipal waste incineration plant with a single furnace, the problem of reduced power generation efficiency arises.

JP 2003-343208 A JP 09-184609 A JP 09-256817 A Japanese Patent Laid-Open No. 09-296921 JP 2009-162452 A

In the present invention, when the above-mentioned problem in the municipal waste incineration plant with a steam turbine power generation device, i.e., waste quality is reduced, the steam generation amount Q (steam flow rate) of the waste heat recovery boiler 1 is reduced. Although the steam pressure loss ΔP in the main steam line 3 is also reduced, the steam inlet steam pressure P _{2 of} the steam turbine 4 is always maintained at the set pressure during the incineration of high quality waste, so that the steam superheater 2 outlet steam pressure P ₁ is decreased by decrease amount ΔPc of steam pressure loss ΔP of the reduced power generation efficiency of the steam turbine generator, and, then b, with the plant structure having a plurality of incinerators, a plurality of incinerators Even in plants that increase the total amount of power generated annually by increasing the number of days that can be operated simultaneously, the waste that has the highest throughput throughout the year is the standard waste that is lower than the high-quality waste. Because, as above Becomes lower pressure than the design value outlet steam pressure P ₁ of the steam superheater 2, it can not be ensured increase total annual power generation amount is to solve cents problems such waste heat recovery boiler by a change in waste matter Even if there is a fluctuation in the amount of steam vaporized in 1, the outlet steam pressure P ₁ of the steam superheater 2 is always maintained at a predetermined constant value, so that high power generation efficiency can be obtained and the total annual power generation can be increased. It is a main object of the present invention to provide a municipal waste incineration plant with a steam turbine power generator and an arithmetic controller for adjusting the steam pressure at the turbine inlet used therefor.

In the invention relating to the operation method of the municipal waste incineration plant with a steam turbine power generator according to claim 1 of the present application, the steam generated in the waste heat recovery boiler 1 of the municipal waste incinerator plant is superheated by the steam superheater 2, and the superheated steam is In a municipal waste incineration plant with a steam turbine power generator configured to generate electricity by supplying it to the pre-pressure controlled steam turbine 4 through the main steam pipeline 3, steam superheat is generated by burning municipal waste with a desired waste quality. When the steam pressure loss ΔP of the main steam line 3 decreases while operating the municipal waste incineration plant under the outlet steam pressure P ₁ and the turbine inlet steam pressure P ₂ , the inlet of the pre-pressure controlled steam turbine 4 is reduced. the steam pressure P _2, by the vapor pressure of P ₂ + [Delta] P _C is increased by decrease [Delta] P _C of the steam pressure loss [Delta] P of the main steam line 3, constant outlet steam pressure P ₁ of the steam superheater 2 Pressure state Holds the one in which the basic configuration of the invention that it has to achieve an increase in the generated power by the with an inlet steam pressure P ₂ + ΔP _C to operate the steam turbine 4.

In the invention of claim 2, steam generated in a waste heat recovery boiler of a municipal waste incinerator plant is superheated by a steam superheater, and the superheated steam is supplied to a pre-pressure controlled steam turbine through a main steam pipe. In a municipal waste incineration plant with a steam turbine power generation device configured to burn municipal waste of desired waste quality, the steam evaporation amount Q of the waste heat recovery boiler, the steam pressure P _{1 at} the outlet of the steam superheater, and the turbine during operation the urban warren incineration plants under the inlet steam pressure P _2, the steam evaporation amount Q is decreased steam pressure loss ΔP of the main steam pipe passage is reduced, the inlet steam pressure P ₂ of the steam turbine, the main holds the outlet steam pressure P ₁ of the steam superheater constant pressure by the steam pressure P ₂ + [Delta] P _C is increased by decrease [Delta] P _C of the steam pressure loss [Delta] P of the steam line, the P ₂ + in the inlet steam pressure [Delta] P _C Thus, the basic configuration of the invention is to increase the power generation efficiency by operating the steam turbine.

According to a third aspect of the present invention, in the second aspect of the invention, a decrease in the amount of vapor evaporation Q is detected from the steam flow rate Q _S in the main steam pipe 3, and the steam pressure loss ΔP is determined from the detected variation in the steam flow rate Q _S. it is obtained to detect the decrease [Delta] P _C of.

The invention of claim 4 is the invention of claim 2, wherein a decrease in the vapor evaporation amount Q is detected from the waste incineration amount Q _W of the operation control device of the municipal waste incinerator, and the detected waste incineration amount Q of the operation control device. from _W fluctuation of is obtained to detect the decrease [Delta] P _C of the steam pressure loss [Delta] P.

  A fifth aspect of the present invention is the municipal waste incinerator plant according to the second aspect of the present invention, wherein the municipal waste incinerator plant comprises a plurality of incinerators and operates the plurality of incinerators in a partial load state. It is a thing.

The invention relating to the calculation controller for steam turbine inlet steam pressure adjustment according to claim 6 includes a steam superheater 2, a pre-pressure controlled steam turbine 4 for supplying superheated steam from the steam superheater 2 through the main steam pipe line 3, and A pre-pressure control valve 18 provided in the vicinity of the steam inlet of the pre-pressure controlled steam turbine 4, a pressure detector 15 provided in the outlet of the steam superheater 2, and a pressure detector provided in the vicinity of the steam inlet of the steam turbine 4. 16 is used for a municipal waste incineration plant with an automatic operation control system with a steam turbine power generator, and an outlet steam pressure P ₁ of the pressure detector 15 and a turbine inlet steam pressure P _{2 of the} pressure detector 16 are inputted. At the same time, a reduction amount ΔP _C of the steam pressure loss ΔP when the steam flow rate fluctuates is calculated from a relationship curve between the steam evaporation amount stored in advance and the steam pressure loss ΔP of the main steam pipe line 3, and the calculated reduction amount ΔP Pressure control signal proportional to _C S _C is output to the pre-pressure control valve 18 to increase the turbine inlet steam pressure P ₂ by the decrease ΔP _C and adjust the turbine inlet steam pressure P ₂ to adjust the outlet steam pressure P ₁ of the steam superheater 2. The basic configuration of the present invention is to always maintain a constant value.

The invention of claim 7 includes a steam superheater 2, a pre-pressure controlled steam turbine 4 that supplies superheated steam from the steam superheater 2 through the main steam piping 3, and a steam inlet near the pre-pressure controlled steam turbine 4. The provided pre-pressure control valve 18, the pressure detector 15 provided at the outlet of the steam superheater 2, the pressure detector 16 provided near the steam inlet of the steam turbine 4, and the evaporation amount detection mechanism of the waste heat recovery boiler 1 Of an automatic operation control type municipal waste incineration plant equipped with a steam turbine power generator equipped with an outlet steam pressure P ₁ of the pressure detector 15, a turbine inlet steam pressure P _{2 of the} pressure detector 16, and an evaporation amount detection mechanism. The steam evaporation amount Q is inputted, and the decrease amount of the steam pressure loss ΔP when the steam evaporation amount Q decreases from the relationship curve between the steam evaporation amount Q stored in advance and the steam pressure loss ΔP of the main steam pipe 3 Calculate ΔP _C and the calculated decrease ΔP _C The pressure control signal S _C that is proportional to output the previous control valve 18 a turbine inlet steam pressure P ₂ is increased by the decrease amount [Delta] P _C, adjusting the turbine inlet steam pressure P ₂ at the time of change of the vapor evaporation Q Thus, the basic configuration of the invention is that the outlet steam pressure P ₁ of the steam superheater 2 is always maintained at a constant value.

  The invention according to claim 8 is the invention according to claim 7, wherein the evaporation amount detecting mechanism is a steam flow rate detector 17 provided in the main steam line 3.

The invention according to claim 9 is the invention according to claim 7, wherein the evaporation amount detection mechanism is a detection mechanism for the waste incineration amount of the operation control device of the municipal waste incinerator.

In the present process invention, vapor evaporation amount of the waste heat recovery boiler 1 Q, the plant under superheater outlet steam pressure P ₁ of 2 and the turbine inlet steam pressure P ₂ during operation, the evaporation amount Q is reduced When the steam pressure loss ΔP in the main steam line 3 decreases, the steam pressure P ₂ at the inlet of the steam turbine is increased by the decrease ΔP _C of the steam pressure loss ΔP in the main steam line 3 to increase P ₂ + ΔP By setting the steam pressure to _C , the outlet steam pressure P ₁ of the superheater 2 is held at a constant pressure value.
As a result, even if the vapor evaporation amount Q decreases due to fluctuations in waste quality and waste combustion conditions, the outlet steam pressure P ₁ of the steam superheater 2 is maintained at a constant set value, and high power generation efficiency is obtained. It is done.

In the present invention, the steam stored in advance from the outlet steam pressure P ₁ of the pressure detector 15, the turbine inlet steam pressure P _{2 of the} pressure detector 16, and the steam evaporation amount Q of the evaporation amount detection mechanism. Using the relationship curve between the evaporation amount Q and the steam pressure loss ΔP of the main steam line 3, the decrease amount ΔP _C of the steam pressure loss ΔP when the vapor evaporation amount Q decreases is calculated, and the calculated decrease amount ΔP _C by outputting a pressure control signal S _C that is proportional to the previous pressure control valve 18 has a configuration which is increased by decreasing the amount [Delta] P _C of the turbine inlet steam pressure P ₂ and the arithmetic.
As a result, by adjusting the turbine inlet steam pressure P ₂ , the outlet steam pressure P ₁ of the steam superheater 2 is maintained at a constant value, and the power generation efficiency can be improved.

It is a steam system schematic diagram of a municipal waste incineration plant with a steam turbine power generator concerning the implementation of the present invention. It is a characteristic curve showing the relationship between the evaporation amount and the steam pressure loss ΔP. It is a structure schematic diagram of the automatic combustion control apparatus of the municipal waste incineration plant with a steam turbine power generator to which the present invention is applied. It is a steam system schematic diagram of the conventional municipal waste incineration plant with a steam turbine power generation device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of a steam system of a municipal waste incineration plant with a steam turbine power generator according to the present invention. In FIG. 1, 1 is a waste heat recovery boiler, 2 is a steam superheater, and 3 is a main steam pipe line. 4 is a steam turbine, 4a is a generator, 5 is a condenser, 6 is a condensate tank, 7 is a deaerator feed pump 7, 8 is a deaerator, 9 is a boiler feed pump, and 10 is a waste heat recovery boiler. , 11 is a steam type air preheater, 12 is a heat utilization device, 13 is a water supply treatment device, 15 and 16 are pressure detectors, 17 is a steam flow rate detector, 18 is a pre-pressure control valve, and 19 is an arithmetic controller. .

That is, a steam flow rate detector 17 and a pre-pressure control valve 18 are provided in the main steam pipe line 3 connecting the steam superheater 2 and the steam turbine 4, and an arithmetic controller 19 for adjusting the turbine inlet steam pressure is provided. points, and the adjustment of the opening degree of the pre-control valve 18 by the control signal Sc from the operation control unit 19, except that to adjust the turbine inlet steam pressure P _2, the other configuration, FIG. 4 It is almost the same as the case of the previous schematic diagram of the steam system.

The arithmetic controller 19 receives the outlet steam pressure P ₁ detected by the pressure detector 15, the turbine inlet steam pressure P ₂ detected by the pressure detector 16, and the steam flow rate Qs detected by the steam flow detector 17. At the same time, the control signal Sc is output to the pre-pressure control valve 18.

  The arithmetic controller 19 stores in advance data indicating the relationship between the steam evaporation amount Q of the waste heat recovery boiler 1 and the steam pressure loss ΔP in the main steam pipe line 3, for example, characteristic curve data as shown in FIG. By applying the relationship between the steam flow rate Qs detected by the steam flow rate detector 17 and the previously known combustion waste quality and the vapor evaporation amount Q to the characteristic curve data, The amount of decrease ΔPc in the steam pressure loss ΔP is calculated from the change in the amount of steam evaporation Q.

When the decrease amount ΔPc of the steam pressure loss ΔP is calculated, the turbine inlet steam pressure P ₂₀ = P required to maintain the outlet steam pressure P ₁ at the same value as before the steam evaporation amount Q fluctuates. _{2 +} Delta] Pc (decrease Delta] Pc of the previous variation of the vapor evaporation Q turbine inlet steam pressure P _{2 +} steam pressure loss [Delta] P) is calculated, increasing the turbine inlet steam pressure P ₂ by reduction Delta] Pc of the steam pressure loss [Delta] P A pressure control signal Sc for generating the pressure is output to the pre-pressure control valve 18.
That is, by increasing the turbine inlet steam pressure P ₂ by the decrease ΔPc of the steam pressure loss ΔP, the outlet steam pressure P ₁ of the steam superheater 2 is maintained at the initial constant value even after the fluctuation of the steam evaporation amount Q. Is done.

The municipal waste to be treated is high-quality waste, and the steam pressure P ₁ = 4.00MPa (G) of the steam superheater 2 planned and designed on the basis of this, and the steam evaporation Q of the waste heat recovery boiler 1 = Q (T / H), Steam pressure loss in main steam line 3 ΔP = 0.20MPa (G), Turbine inlet steam pressure P ₂ ＝ 3.80MPa (G) When the vapor evaporation amount Q decreases to Q ′ and the steam pressure loss ΔP in the main steam pipe line 3 decreases to 0.15 MPa (G), the arithmetic controller 19 changes the waste quality. The steam pressure loss ΔP '= 0.15MPa (G) corresponding to the steam evaporation amount Q' reduced by the above is calculated, and the decrease amount of steam pressure loss ΔP ΔPc = ΔP-ΔP '= 0.05MPa (G) is calculated. The

Then, this Delta] Pc = 0.05 MPa pressure control signal Sc corresponding to (G) is output to the front control valve 18, a turbine by previous pressure control valve 18 is actuated in the closing direction the inlet steam pressure P ₂₀ is P ₂ + ΔPc = 3.80 + 0.05 = 3.85 MPa (G). As a result, the outlet steam pressure P ₁ of the steam superheater 2 is maintained at the set value P ₁ = 4.00 MPa (G) even when the steam evaporation amount Q changes to the evaporation amount Q ′.

That is, in the present invention, the matters relating to the device design such as the steam condition of the steam superheater 2 and the pipe diameter of the main steam pipe 3 are not different from the conventional ones. First, the steam pressure loss ΔP is derived in accordance with the steam evaporation amount Q (generated amount), and the turbine inlet steam pressure P ₂ is operated based on this, whereby the outlet steam pressure P ₁ of the steam superheater 2 is Operate at a constant (4.00 MPa (G)).
In calculating the steam pressure loss ΔP and controlling the turbine inlet steam pressure P ₂ , the pre-pressure control is performed using a characteristic curve between the steam evaporation amount Q and the steam pressure loss ΔP stored in advance in the arithmetic controller 19. The pressure control signal Sc to be output to the valve 18 is calculated and output.

As the vapor evaporation amount Q, the setting value of the automatic control device or the actual measurement value may be used directly, or the deviation amount between the setting value of the automatic control device and the actual measurement value may be used. It is also possible to use the value calculated in this way.
In addition, the calculation of the steam pressure loss ΔP is not limited to the steam evaporation amount Q of the waste heat recovery boiler 1, but an alternative index, for example, the number of operating furnaces, waste quality, waste, which are indices used for incinerator waste combustion. The incineration amount Qw may be used as an alternative to the vapor evaporation amount Q.

FIG. 3 is a schematic configuration diagram of the automatic combustion control device of the waste heat recovery boiler 1 used in the present invention. The main parts of the automatic combustion control are generally a combustion amount control (constant evaporation control) unit and a furnace outlet oxygen. are formed from the density control unit or the like, as one of the combustion amount control control element in (evaporation amount constant control) unit, is plus control of turbine inlet steam pressure P _2, for use in the present invention It corresponds to an automatic combustion control device.

In power generation by the steam turbine generator 4a, generally higher turbine inlet steam pressure P ₂ is high-efficiency power generation. Therefore, the turbine inlet steam pressure P ₂ garbage quality, pear in regardless constant and the operation method in waste volume, steam evaporation and other vapor pressure of the main steam pipe passage 3 indicator based on as in the present invention By deriving the loss ΔP and setting and controlling the turbine inlet steam pressure P ₂ accordingly, the outlet steam pressure P ₁ of the steam superheater 2 can be kept high even in the case of standard waste with the highest frequency of appearance. , it is possible to improve the high to the power generation efficiency turbine inlet steam pressure P _2.

Example 1
For example, two furnaces with a waste incineration rate of about 170 T / day (evaporation rate 40 t / h) are installed, and the design conditions for high-quality waste are the same as the steam pressure at the outlet of the steam superheater 2 P ₁ = 4.00 MPa (G) , steam pressure loss ΔP = 0.20MPa (G), when the turbine inlet steam pressure P _{2 =} 3.80MPa (G), in the waste heat recovery in the waste matter is 2 furnace operation by changing the reference debris from high quality dust When the steam evaporation amount Q of the boiler 1 decreases from the design condition and the steam pressure loss ΔP calculated from the steam evaporation amount Q is 0.15 MPa (G), the outlet steam pressure P ₁ = 4.00 MPa (G) , And turbine inlet steam pressure P ₂ = 3.85 MPa (G). Further, the generated power (kW) at this time increases by 10 (kW) in either one furnace operation or two furnace operation.
Now, assuming that 2 furnace operation days are 150 days and 1 furnace operation day is 205 days, the generated power (kW) and annual power generation (MWh) are as shown in Table 2. It is possible to increase the generated power and the amount of generated power without greatly improving.

(Example 2)
In addition, in order to increase the total amount of power generation per year, an operation method has been developed in which two furnaces are operated in a partial load state and the number of days for operating the two furnaces is extended (Japanese Patent Laid-Open No. 2009-16242, Patent Document 5). Even in the case of such an operation method, by applying the present invention, it is possible to increase the generated power and the generated power amount without greatly improving the municipal waste incineration plant with a steam turbine power generator.
For example, in a plant with the same design conditions as in Example 1, the most frequently generated standard waste per year is 90% load for each incinerator when operating in two furnaces, and 100% when operating in one furnace. When an operation plan for incineration with a load is made, if the steam pressure loss ΔP calculated from the steam evaporation Q is 0.15 MPa (G), the generated power (kW) and annual generated power (MKh) are 3 and both increase.

In the operation method according to the present invention, the outlet steam pressure P ₁ of the conventional steam superheater 2 that has fluctuated depending on the waste quality, the incineration load, etc. is always maintained at a constant pressure of 4.00 MPa (G). Therefore, maintenance management of the steam superheater 2 and the steam turbine 4 becomes easy.
Further, since the operation method according to the present invention operates the municipal waste incineration plant within the conventional boiler design conditions, there is no need to make the conventional design conditions higher than the conventional boiler design conditions.
Further, in the present invention, when deriving and setting the turbine inlet steam pressure P ₂ of the steam pressure loss [Delta] P, using the waste heat steam evaporation amount of recovery boiler 1 Q or incinerator operating indicators in place of it (municipal waste combustion quantity) Although a configuration, also by manually controlling the turbine inlet steam pressure P ₂ by the operator, it is a matter of course that the same effect can be obtained.

  The present invention can be applied not only to an incineration plant for municipal waste but also to a combustion furnace using a generated gas in an industrial waste or sludge incineration plant, steel making, or the like as a heat source.

Q Vapor evaporation
P ₁ outlet steam pressure
P ₂ Turbine inlet steam pressure ΔP Steam pressure loss ΔPc Decrease in steam pressure loss
Qs Steam flow rate of main steam pipeline
Qw Incinerator operation control device and / or municipal waste incineration amount
Sc Pressure control signal 1 Waste heat recovery boiler 2 Steam superheater 3 Main steam pipeline 4 Steam turbine 4a Generator 5 Condenser 6 Condensate tank 7 Deaerator feed pump 8 Deaerator 9 Boiler feed pump 10 Economizer 11 Steam Type air preheater 12 heat utilization device 13 water supply treatment device 14 main steam control valve 15 pressure detector 16 pressure detector 17 steam flow rate detector 18 pre-pressure control valve 19 arithmetic controller

Claims (9)

Steam turbine generator configured to generate electricity by heating the steam generated in the waste heat recovery boiler of a municipal waste incinerator plant with a steam superheater and supplying the superheated steam to the pre-pressure controlled steam turbine through the main steam line in urging municipal waste incineration plants, by burning municipal waste of the desired waste matter, the main cities warren incineration plant during operation under the outlet steam pressure P ₁ and the turbine inlet steam pressure P ₂ of the steam superheater When the steam pressure loss [Delta] P of the steam pipe passage is reduced, the inlet steam pressure P ₂ of the steam turbine, the steam pressure P ₂ + [Delta] P _C is increased by decrease [Delta] P _C of the steam pressure loss [Delta] P of the main steam line wherein the outlet steam pressure P ₁ of the steam superheater and holds constant pressure, it has a structure to improve the power generation efficiency by operating a steam turbine with an inlet steam pressure of the P ₂ + [Delta] P _C by The method of operating a steam turbine power generation system with municipal waste incineration plants, characterized. Steam turbine generator configured to generate electricity by heating the steam generated in the waste heat recovery boiler of a municipal waste incinerator plant with a steam superheater and supplying the superheated steam to the pre-pressure controlled steam turbine through the main steam line In the municipal waste incineration plant, the municipal waste of the desired waste quality is burned to reduce the steam evaporation amount Q of the waste heat recovery boiler, the outlet steam pressure P ₁ of the steam superheater, and the steam pressure P ₂ of the turbine inlet in urban warren incineration plant during operation, the steam evaporation amount Q is decreased steam pressure loss ΔP of the main steam pipe passage is reduced, the inlet steam pressure P ₂ of the steam turbine, the steam pressure loss in the main steam line It holds the outlet steam pressure P ₁ of the steam superheater constant pressure by the steam pressure P ₂ + [Delta] P _C is increased by decrease [Delta] P _C of [Delta] P, at the inlet steam pressure of the P ₂ + ΔP _C With steam turbine A method for operating a municipal waste incineration plant with a steam turbine power generator, characterized in that the power generation efficiency is increased by operating the power plant. The decrease in the vapor evaporation amount Q is detected from the steam flow rate Q _S in the main steam pipe line, and the decrease ΔP _C in the steam pressure loss ΔP is detected from the detected variation in the steam flow rate Q _S. The operation method of the municipal waste incineration plant with a steam turbine power generator described in 1. The decrease in vapor evaporation Q is detected from the value of waste incineration amount Q _W of the operation control device of the municipal waste incinerator, and the decrease in steam pressure loss ΔP is detected from the change in the waste incineration amount Q _W of the detected operation control device. the method of operating a steam turbine power generation system with municipal waste incineration plant according to claim 2 which is adapted to detect a [Delta] P _C.   The city with a steam turbine power generator according to claim 2, wherein the municipal waste incinerator plant is a municipal waste incinerator plant having a plurality of incinerators and operating the plurality of incinerators in a partial load state. Operation method of garbage incineration plant. A steam superheater, a prepressure-controlled steam turbine that supplies superheated steam from the steam superheater through the main steam pipeline, a prepressure control valve provided near the steam inlet of the steam turbine, and a steam superheater provided at the outlet Used in a municipal waste incineration plant with an automatic operation control system steam turbine generator equipped with a pressure detector and a pressure detector provided in the vicinity of the steam inlet of the steam turbine, and an outlet steam pressure P ₁ of the pressure detector together and a turbine inlet steam pressure P ₂ of the pressure detector is inputted, the amount of decrease in pre-stored steam pressure loss ΔP during steam flow variation from the relationship curve between the steam pressure loss ΔP of the steam flow rate and the main steam pipe passage calculates the [Delta] P _C, causes the pressure control signal S _C that is proportional to the amount of decrease [Delta] P _C which is the operation and outputs the previous control valve 18 to increase the turbine inlet steam pressure P ₂ by the decrease amount [Delta] P _C, the turbine inlet adjusting the steam pressure P ₂ Calculation control unit for adjusting the steam turbine inlet steam pressure, characterized in that it has a structure that holds the outlet steam pressure P ₁ of the steam superheater 2 always a constant value by Rukoto. A steam superheater, a prepressure-controlled steam turbine that supplies superheated steam from the steam superheater through the main steam pipeline, a prepressure control valve provided near the steam inlet of the steam turbine, and a steam superheater provided at the outlet A pressure detector, a pressure detector provided in the vicinity of a steam inlet of a steam turbine, and a municipal waste incineration plant with a steam turbine power generator of an automatic operation control system equipped with an evaporation amount detection mechanism of a waste heat recovery boiler, The pressure detector outlet steam pressure P ₁ , the pressure detector turbine inlet steam pressure P _2, and the steam evaporation amount Q of the evaporation amount detection mechanism are inputted, and the previously stored steam evaporation amount Q and the main steam pipe line decrease amount [Delta] P _C is calculated, the pressure control signal S _C to the front pressure proportional to the amount of decrease [Delta] P _C that the operation of the steam pressure loss [Delta] P at the time of reduction of the relationship curve from the steam evaporation amount Q of the steam pressure loss [Delta] P of Output to control valve 18 and turbine inlet The steam pressure P ₂ is increased by the decrease amount [Delta] P _C, maintained at all times a constant value of the outlet steam pressure P ₁ of the steam superheater 2 by adjusting the turbine inlet steam pressure P ₂ at the time of change of the vapor evaporation Q Configuration An arithmetic controller for adjusting the steam pressure at the inlet of the steam turbine, characterized in that   The operation controller for steam turbine inlet steam pressure adjustment according to claim 7, wherein the evaporation amount detection mechanism is a steam flow rate detector provided in the main steam pipe line. The operation controller for steam turbine inlet steam pressure adjustment according to claim 7, wherein the evaporation amount detection mechanism is a waste incineration amount detection mechanism of an operation control device of a municipal waste incinerator.

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