JP5060313B2 - Operation method of waste treatment facility with power generation equipment - Google Patents

Description

  In the present invention, waste such as municipal waste and industrial waste is incinerated, pyrolyzed or melted in a waste incinerator, a pyrolysis gasification melting furnace, a direct melting furnace or the like, and treated as a waste. The combustion exhaust gas generated in the furnace is guided to the boiler to generate steam, and the generated steam is superheated by a superheater to form superheated steam, and then the superheated steam is guided to a power generator composed of a steam turbine and a generator to generate power. In particular, in the waste treatment facility with power generation equipment composed of multiple furnaces, the operation load of each waste treatment furnace is higher than the rated operation. Operation method of waste treatment facilities with power generation facilities that lowers each waste treatment furnace according to the amount of waste treatment and increases the power generation amount by increasing the number of days of operation by multiple furnaces In It is intended to.

In general, waste treatment facilities equipped with waste incinerators that incinerate waste such as municipal waste and industrial waste, and waste treatment furnaces such as pyrolysis gasification and melting furnaces that thermally decompose and melt waste In the facility size planning, because the future population increase or disaster is predicted, the amount of waste that is actually processed is often smaller than the amount of waste that is planned to be processed annually.
For this reason, as a form of operation of a waste treatment facility normally composed of two or three furnaces, a waste treatment facility composed of two furnaces is rated for one furnace and a waste composed of three furnaces. In the treatment facility, the period during which the reactor is operated in the two-furnace rated operation or the one-furnace rated operation becomes longer.

  Further, in recent waste treatment facilities, power generation equipment including a steam turbine and a generator is often attached as a means for recovering energy from waste (for example, Patent Document 1). Patent Document 2 and Patent Document 3). The capacity of power generation equipment attached to waste treatment facilities is often determined based on the maximum rated treatment load.

  However, since the actual amount of waste processed is less than the planned amount of waste treated annually, the total amount of electricity generated annually at the waste treatment facility with power generation facilities is considerably smaller than the amount of electricity generated during the annual planned treatment. It will be.

For example, when the planned processing amount of waste per day at the waste treatment facility is 240 t and the waste processing furnace is composed of two furnaces, the rated processing amount of waste per furnace is 120 t / day. It is.
In general waste treatment facilities, the number of operating days per furnace per year is often 280 days. In a waste treatment facility composed of two furnaces, 67,200 t (280 days) per year. × 120 t / day · furnace × 2 furnace).
In a waste treatment facility consisting of two furnaces, a common resting furnace (maintenance of common equipment and equipment such as steam turbines, generators, air compressors, wastewater treatment facilities, pure water facilities, etc.) When both furnaces are closed for about 20 days a year, operation with two furnaces is 215 days, operation with one furnace is 65 days, and maintenance of each furnace is performed for 65 days when the furnace is stopped. (See FIG. 3).

However, the actual amount of waste treatment facility treatment is expected to increase due to population growth and disasters at the time of facility size planning, so it will be less than the annual amount of waste treatment planned. This is 53,760 t / year, which is about 80% of the planned processing amount. In this case, assuming that the common shutdown (both reactors are closed) is 20 days as in the facility scale plan, the operation mode of the waste treatment facility is 103 days for rated operation with 2 furnaces, and 1 for 1 reactor. 121 days (see FIG. 4).
Thus, in a waste treatment facility with power generation facilities consisting of two furnaces, if the actual annual treatment amount of waste is less than the rated treatment amount, the number of operating days by two furnaces as described above To reduce the amount of waste.

By the way, in the case of ordinary waste such as municipal waste, the ratio of the maximum value / reference value of the heat generation amount of waste is 1.5 times in consideration of seasonal fluctuations and fluctuations in the properties of waste to be treated according to the collection form. There are often.
In addition, when the power generation equipment capacity is selected at the maximum load (rated operation with two furnaces), the generated load of the waste being processed is at the standard level, and the generator load is 1/3 of the rated when operating with one furnace. Considering the change in waste properties during operation (waste quality change), power generation may not be possible due to the turndown of the generator.

Therefore, in the waste treatment facility with power generation equipment composed of two furnaces, the following power generation amount reduction occurs.
That is, in the waste treatment facility with power generation equipment having a two-furnace configuration, the operation days of the furnace are set in accordance with the rated treatment amount of the waste, and therefore, the operation days of two furnaces and the operation days of one furnace are used. As a result, the power generation equipment that is a common equipment is operated with drastic fluctuations in which the amount of steam on the inlet side is about 100% or 50%, and the amount of power generation throughout the year is reduced.
In addition, when the heat generation amount of waste is high and the generator capacity is set in the two-furnace rated operation, when processing waste from the low quality waste to the standard waste, it is not possible to generate power when operating with one furnace. There is a case.

JP-A-10-26010 Japanese Patent Laid-Open No. 10-238732 JP 2002-250513 A

  The present invention has been made in view of such problems, and an object of the present invention is to increase the amount of power generation while suppressing a decrease in the total amount of power generation during the year by performing efficient operation with multiple furnaces. Another object of the present invention is to provide a method for operating a waste treatment facility with a power generation facility that can generate power even when the amount of waste treated annually or the amount of heat generated by waste is small.

  In order to achieve the above object, according to the first aspect of the present invention, waste is incinerated, pyrolyzed or melted in a plurality of waste treatment furnaces, and the combustion exhaust gas from each waste treatment furnace is boiler. A plurality of furnaces that generate steam by supervising the generated steam, superheating the generated steam by a superheater, and introducing the superheated steam to a power generation facility composed of a common steam turbine and generator. In the waste treatment facility with power generation equipment composed of the following, the operation load of each waste treatment furnace is lowered below the rated load, and each waste treatment furnace is operated at partial load according to the amount of waste treated. The feature is that the power generation amount is increased by increasing the operation days by the furnace.

  Further, the invention of claim 2 of the present invention is characterized in that a generator with a small generator capacity that requires high-voltage power reception is used as the generator of the power generation facility, and the power generation facility with a small generator capacity is used to generate power. is there.

In the present invention, the operation load of each waste treatment furnace is lowered below the rated load, and each waste treatment furnace is partially loaded in accordance with the amount of waste to be treated, so that the number of operation days by a plurality of furnaces is increased. The amount of power generated from the common power generation facility will increase.
In addition, the present invention uses a generator with a small generator capacity that only requires high-voltage power reception as the generator of the power generation facility, and generates power with the power generation facility with a small generator capacity, thereby further increasing the amount of power generation. It is possible to reduce costs such as initial costs.
Furthermore, since the present invention generates power with a power generation facility having a small generator capacity, even when the annual amount of waste processed or the amount of heat generated by the waste is small, the generator can be prevented from being turned down to generate power. This will increase the amount of power generation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a waste treatment facility with power generation equipment composed of a plurality of furnaces for carrying out the method of the present invention. The waste treatment facility with power generation equipment comprises two stoker-type incinerators 1 for incinerating waste. Connected to the downstream side of each stoker-type incinerator 1 and installed on the downstream side of each boiler 2 that recovers thermal energy from the combustion exhaust gas generated in each stoker-type incinerator 1 and generates steam. An economizer 3 for further recovering thermal energy from the combustion exhaust gas, a temperature reduction tower 4 installed downstream of each economizer 3 for injecting cooling water into the combustion exhaust gas to cool the combustion exhaust gas, and each temperature reduction tower 4 is installed downstream of the bag filter 5 to remove the dust contained in the exhaust gas, and the induction fan is provided downstream of each bag filter 5 to attract the combustion exhaust gas in each stoker type incinerator 1. 6 and each Installed on the downstream side of the draft fan 6, the wet cleaning tower 7 for removing the acid gas in the exhaust gas, and installed on the downstream side of each wet cleaning tower 7, heating the reduced temperature exhaust gas to turn the exhaust gas into white smoke The gas reheater 8 for preventing the exhaust gas, the chimney 9 for releasing the exhaust gas into the atmosphere, provided on the downstream side of each gas reheater 8, and the outlet side of each stoker incinerator 1, each boiler 2 A superheater 10 that further superheats the steam generated in step 1, a steam turbine 11 that is driven by superheated steam from each superheater 10, and a generator 12 that is driven by the steam turbine 11 to generate electric power (this The power generation facility 13 is a common facility).

Thus, in the waste treatment facility with the power generation equipment 3, the combustion exhaust gas generated in each stoker type incinerator 1 is led to the boiler 2 to generate steam, and the generated steam is superheater 10. Is further heated to generate superheated steam, and the superheated steam is guided to the common power generation facility 13 through the common accumulator 14 to generate power. In addition, the electric power obtained by the power generation facility 13 is consumed in the waste treatment facility, and surplus power is sold to the electric power company.
Further, the steam that has passed through the steam turbine 11 of the power generation facility 13 is condensed by the condenser 15, and then supplied to each economizer 3 from the condensate tank 16 through the deaerator 17 by the water supply pump 18. It is returned to the boiler 2 of the stoker type incinerator 1.

  The waste treatment facility with power generation facilities is planned to have a planned throughput of 240 t / day and a rated throughput of 120 t / day / furnace. The number of days is 280, and the facility is configured to incinerate 67,200 tons of waste in one year.

  By the way, in the waste treatment facility with power generation equipment, when the actual annual treatment amount of waste is 80% of the planned treatment amount (67,200 t), the annual treatment amount of waste becomes 53,760 t. Considering a common outage due to maintenance of common system facilities and equipment such as air compressors, wastewater treatment facilities, and deionized water facilities (both furnaces are closed), the rated operation with two furnaces is 103 days, 1 The rated operation by the furnace is the operation mode for 121 days.

  However, the waste treatment facility with the power generation equipment operates the partial load operation of each stalker-type incinerator 1 according to the amount of waste, by reducing the operation load of each stalker-type incinerator 1 below the rated load. The number of operating days is increased to increase power generation. At this time, the partial load operation of each stoker type incinerator 1 is a partial load operation that allows the operation with two furnaces to be continued as long as possible.

In this embodiment, in the waste treatment facility with power generation equipment, the operation load of each stoker type incinerator 1 is set to 80% partial load operation of the rated operation, and the waste processing amount per furnace is 96 t. / Day (120t / day × 80/100), the number of operating days by two furnaces is increased.
In other words, this waste treatment facility with power generation facilities has an operation mode in which the operation days by two furnaces are 215 days, the operation days by one furnace is 65 days, the common furnace is set to 20 days, The shutdown period is 65 days, and maintenance of each furnace is performed during this period.

  In addition, this waste treatment facility with power generation facilities is suitable for partial load operation based on past results of carrying in waste, past heat generation results, waste pits (not shown), and boiler evaporation. Is to be done automatically.

FIG. 2 is a flowchart showing an outline of the partial load operation control of the waste treatment facility with power generation equipment described above, and shows an example in which the amount of heat input to the furnace is made constant.
The total waste heat input N for the year is calculated based on the past waste carry-in result W and the past waste heat generation result Q.
In addition, past waste carry-in results W are obtained by measuring the amount of waste with a weighing machine installed in the waste treatment facility, and inputting the result of the weighing into the storage device daily, monthly, or annually. can get.
Further, the past waste heat generation amount Q is calculated by (boiler absorption heat amount + exhaust gas heat generation amount + unburned loss + boiler combustion furnace heat dissipation loss) / garbage treatment amount or the like. The individual calculations are well-known and will be omitted.
Accordingly, the total waste heat input N for the year becomes the annual waste carry amount W × the average waste heat generation amount Q for the year.
Then, by dividing the annual total waste heat input N by the average number of days of furnace operation (operating days with a processing load that allows two furnace operations to continue as much as possible), the processing heat amount G per furnace day Is calculated. In this example, the model processing plan for waste is 215 days for operation by two furnaces and 130 days for one furnace.
The furnace processing amount L is calculated from the past heat generation amount G and the current heat generation amount q. Based on this, the processing load is set, and the boiler evaporation amount is set. This setting may be daily, weekly, or monthly. The boiler evaporation amount is conventionally controlled by controlling the amount of waste supplied to the furnace and controlling the input of combustion air.
When the level of waste in the waste pit (not shown) is fed back as a result of the processing load setting, and the level of waste in the waste pit falls below the level of waste in the waste pit determined from the model processing plan If the level of waste in the garbage pit is higher than the level of waste in the garbage pit determined from the model processing plan, correction is performed such as raising the setting value.
By performing these controls / calculations, stable partial load operation in two furnaces is realized throughout the year, and the amount of power generation increases.

  The flow chart of FIG. 2 shows an example in which the amount of heat input to the furnace is made constant, but it also includes simply making the amount of treatment constant. Further, if the term of heat quantity of the flow is deleted, the operation is constant weight load.

Table 1 below shows the surplus power when a generator 12 with a generator capacity of 2,900 kW is installed in a waste treatment facility and the furnace is rated and when the furnace is partially loaded (80% of rated operation). This is a trial calculation. When the furnace is in rated operation, the amount of waste treated is 120 t / day, and when the furnace is in partial load operation, the amount of waste treated is 96 t / day.
As is clear from Table 1, when a generator 12 with a generator capacity of 2,900 kW is installed in a waste treatment facility, surplus power is required in one year when the furnace is partially loaded rather than rated at the furnace. The amount will increase by 503 GW.

  In addition, in the waste treatment facility with power generation equipment, the waste treatment facility in which the generator 12 having a generator capacity of about 3,000 kW is installed has a high construction cost for drawing in from the special high-voltage wire at the time of facility planning. Considering the reduction of the initial cost, the generator 12 having a generator capacity of about 1,990 kW, which is less than 2,000 kW, can be installed by avoiding the special high-voltage power reception and is often installed.

Table 2 below shows surplus power when a generator with a generator capacity of 1,990 kW is installed in a waste treatment facility and the furnace is rated and when the furnace is partially loaded (80% of rated operation). This is a trial calculation. When the furnace is in rated operation, the amount of waste treated is 120 t / day, and when the furnace is in partial load operation, the amount of waste treated is 96 t / day.
As is clear from Table 2, when the generator 12 with a generator capacity of 1,990 kW is installed in the waste treatment facility, surplus power is required in one year when the furnace is partially loaded rather than rated at the furnace. As the amount increases by 1,050 GW and the generator capacity is smaller, the amount of power generation is further increased.

In this way, in the waste treatment facility with power generation facilities composed of multiple furnaces, the operation load of each waste treatment furnace is lowered from the rated operation, and each waste treatment furnace is set according to the amount of waste treated. The amount of power generation can be increased by performing partial load operation and increasing the number of operating days by two furnaces.
In addition, when the generator 12 of the power generation facility 13 uses the generator 12 that avoids the special high-voltage power reception and can receive the high-voltage power, and generates power with the generator 12 having a small generator capacity, the power generation amount is further increased. It is possible to reduce the initial cost and the like.
Furthermore, since the generator 12 having a small generator capacity is used to generate power, the generator 12 can be prevented from being turned down even when the annual amount of waste processed or the amount of heat generated by the waste is small. It can be carried out.

  In the above embodiment, the waste is incinerated in the stoker type incinerator 1, but in other embodiments, the waste is incinerated in the fluidized bed incinerator. Alternatively, the waste may be pyrolyzed or melted in a pyrolysis gas gasification melting furnace or a direct melting furnace. In this case as well, the same effects as when the waste is incinerated can be obtained.

It is a schematic system diagram of the waste treatment facility with power generation equipment for implementing the method of the present invention. It is a flowchart figure which shows the outline | summary of the partial load operation control of the waste disposal facility with power generation equipment shown in FIG. It is explanatory drawing which shows the driving | operation form at the time of the plan of the waste disposal facility comprised with 2 furnaces. It is explanatory drawing which shows the actual driving | operation form of the waste disposal facility comprised by 2 furnaces.

Explanation of symbols

  1 is a waste treatment furnace, 2 is a boiler, 10 is a superheater, 11 is a steam turbine, 12 is a generator, and 13 is power generation equipment.

Claims (2)

  Waste is incinerated, pyrolyzed or melted by multiple waste treatment furnaces, and combustion exhaust gas from each waste treatment furnace is introduced to the boiler to generate steam, and the generated steam is superheated by a superheater. Each waste in a waste treatment facility with a power generation facility composed of multiple furnaces that generates superheated steam and directs the superheated steam to a power generation facility composed of a common steam turbine and generator. Reduced the operation load of the treatment furnace from the rated load and operated each waste treatment furnace in partial load according to the amount of waste treated, and increased the number of days of operation by multiple furnaces to increase the power generation amount. A method for operating a waste treatment facility with power generation facilities.   2. The waste with a power generation facility according to claim 1, wherein a generator with a small generator capacity that requires high-voltage power reception is used as a generator of the power generation facility, and the power generation facility has a small generator capacity. How to operate the treatment facility.

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