JPH0642701A - Dual-purpose electricity and steam generating plant utilizing variable pressure combustion type incinerator and method of operating said plant - Google Patents

Abstract

PURPOSE:To regulate a combustion temperature of combustibles by changing pressure in an incinerator and reduce a thermal stress to be applied to the incinerator at the starting of operation of a plant by making the amount of both electric power and hot heat to be supplied variable without operating the plant under high pressure at all times. CONSTITUTION:During a period of the winter season, heat is mainly supplied. That is, an inlet change-over valve 5 is changed over to the side of a pressure reducing pump 4, and an outlet change-over valve 10 is changed over to the side of a heat utilizing system 9. By this method, internal pressure in an incinerator 2 is controlled to a normal pressure or therebelow, and a combustion temperature of waste material is decreased lower than a normal level. During a period of the summer season, electric power is mainly supplied. The inlet change-over valve 5 is changed over to the side of a compressor 3, and the outlet change-over valve 10 is changed over to the side of a steam turbine 6. By this method, internal pressure in the incinerator 2 increases, whereby a combustion temperature of waste material is elevated. Thus, the amount of both electric power and hot heat to by supplied can be made variable according to users' demand, whereby internal pressure in the incinerator is regulated at the starting of operation, and a combustion temperature of waste material can be controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined heat and power plant using a variable pressure combustion type incinerator and a method of operating the combined heat and power plant. -Quality of demand (heat or electricity)
The present invention relates to a combined heat and power plant using a waste incinerator and a method of operating the same, in which the conversion ratio between heat and electric power is variable according to the above, and a high heat utilization rate is realized.

[0002]

2. Description of the Related Art In recent years, how to treat waste has been taken up as a social problem, but in most cases, it is incinerated. As a proposal to effectively utilize the heat generated by the combustion process of waste, the thermal energy of the combustion gas of the incinerator is recovered as steam by a waste heat boiler, and the generated steam is degassed by the high-pressure header and air residual heat. Gas generator, hot water supply in the factory, heating, etc., and send the rest to a turbine for power generation, or "Characteristics and economics of highly efficient gas turbine combined heat and power generation system using recycled gas from municipal waste" (electricity (Gakuron D, Vol 107, No. 7, 362)
As described in (1), the combustion gas of the municipal waste has a low calorie and produces little thermal NOx, and may be used as a gas turbine fuel system. The latter aims to increase the amount of power generation by increasing the temperature at the inlet of the gas turbine expander as high as possible.

[0003] Usually, the combustion treatment of domestic waste is often performed relatively near the urban living environment, and the heat associated with the combustion of the waste is heated according to different heat demands in summer and winter, for example, in the winter. It is desirable that it can be used freely in different ways, such as by using it as a source of electricity and supplying it to households, and converting it into electric energy for cooling in the summer, but in the above means, for example, in the case of the former Means that the thermal energy of the combustion gas of the incinerator is simply recovered as steam by the waste heat boiler and then redistributed as warm heat or electricity, and the thermal efficiency is low. It is difficult to make a large change in the incinerator, and since the incinerator is always operated at a high pressure, the incinerator has a short life.

[0004]

The present invention has been made in response to the social demands as described above, and operates a combined heat and power plant under optimum conditions according to the quality of energy demand (heat or electricity). At the same time, it is intended to extend the life of the incinerator by reducing the thermal stress applied to the incinerator body at the time of starting the plant without constantly operating at high pressure.

[0005]

In order to achieve the above-mentioned object, the present invention allows the combustion temperature to be arbitrarily changed by adjusting the pressure in the incinerator, which is required under high thermal efficiency. Realize operation that meets energy demand.
Therefore, the present invention basically uses an incinerator having a combustion container whose internal pressure can be adjusted, and in an operating method of a combined heat and power plant that generates and supplies electric power and warm heat by using combustion heat of combustible material, A combined heat and power plant using a variable pressure combustion type incinerator, characterized in that the pressure in the incinerator is changed to arbitrarily adjust the combustion temperature of the combustible material to change the amount of electric power and the amount of heat supplied. The driving method of is disclosed.

The present invention also provides a variable pressure incinerator having a heat transfer tube for recovering combustion heat of a combustible material to generate steam or hot water, and a combustible material in the incinerator, as a system for realizing the above method. A supply device for supplying, a compressor and a decompression pump for adjusting the pressure in the incinerator, an inlet switching valve for switching it, a steam turbine for recovering power from the steam from the heat transfer tube, and a power recovery Condenser for condensing the steam of, the heat utilization system for utilizing the heat of the hot water from the heat transfer tube, and the outlet for introducing the steam or the warm water from the heat transfer tube to the steam turbine or the heat utilization system A combined heat and power plant having a variable pressure combustion type incinerator characterized by comprising a switching valve is also disclosed.

As the combustible material, it is particularly effective to use a waste material, although not limited thereto. It is also a preferred embodiment to add a desalination apparatus and utilize the heat obtained in the incinerator to produce tap water or tap water from the sewage and at the same time to condense the sewage to downsize the sewage treatment facility. .

[0008]

As shown in FIG. 3, the effect of the pressure on the heat generation amount of the combustible material is that the heat generation amount increases remarkably up to a certain pressure. Therefore, even when the same amount of combustible material is burned in the incinerator, the calorific value greatly changes depending on whether the pressure in the incinerator is atmospheric pressure or lower or a considerably high pressure, When a heat transfer tube filled with water is placed in the incinerator, the amount of heat generated is low in the case of low pressure combustion, so the water in the heat transfer tube becomes warm water, and the amount of heat generated in the case of high pressure combustion is Since it is large, the water in the heat transfer tube becomes steam with a sufficient amount of heat.

The present invention basically uses such a phenomenon, and in the case of the operation mainly based on the power supply, the inlet switching valve is switched to the compressor and the internal pressure of the incinerator is raised to burn the waste. While increasing the temperature, the amount of waste supplied from the waste supply device is increased, the amount of heat generated in the incinerator is significantly increased, and the amount of steam increases the amount of steam generated or steam pressure in the heat transfer tube. Then, the outlet switching valve is switched to the steam turbine, and the generated steam is introduced to generate power.

In the case of the operation mainly for supplying heat, the inlet switching valve is switched to a decompression pump, the internal pressure of the incinerator is lowered to atmospheric pressure or below atmospheric pressure, and hot water or saturated steam is generated in the heat transfer pipe, The outlet switching valve is switched to the heat utilization system, and the generated hot water or saturated steam is introduced to supply heat. To supply the waste to the incinerator, the waste is pressurized and supplied by the combustible material supply device to which a screw feeder or the like is applied after crushing with a crusher installed in advance. Further, the residue after incineration is discharged from the incinerator by a discharge device that applies a screw feeder or the like.

Further, a desalination device is added to the heat utilization system side to utilize the heat obtained in the incinerator to produce tap water or tap water from the sewage, and at the same time, the sewage is concentrated to treat the sewage. Miniaturize equipment.

[0012]

EXAMPLES The present invention will be described in more detail based on the following examples. FIG. 1 shows a system diagram of a system in the case of operating a combined heat and power plant using a variable pressure combustion type incinerator according to the present invention using domestic waste as combustible material. Basically, this combined heat and power plant uses a combustion waste incinerator as a container whose internal pressure can be adjusted and changes the internal pressure of the incinerator to arbitrarily adjust the combustion temperature of the waste to supply power to the demand side. And / or a system in which the amount of heat is variable.

In the figure, reference numeral 2 is a variable pressure type incinerator in which a heat transfer tube 1 for recovering combustion heat of waste to generate steam or hot water is installed. In the variable pressure type incinerator 2, a compressor 3 for feeding compressed air into the incinerator 2 and a decompression pump 4 for reducing the pressure in the incinerator 2 are provided. It is mounted via an inlet switching valve 5 for switching between the exhaust gas and the exhaust gas. In addition, the switching valve 5 has a compressor 3
A structure may be provided in which the compressed air from is distributed to the compressor 3 side and the exhaust pump 4 side.

The steam and / or hot water which is the output from the heat transfer tube 1 is branched into two directions in the outlet switching valve 10, one of which is a steam turbine 6 for recovering power from the steam.
And the other is sent to the heat utilization system 9 that utilizes the heat of hot water. This branch may be a selective branch that allocates all to either one. The steam turbine 6 has a condenser 7 for condensing steam after power recovery, and the condensed water from the condenser 7 is sent to a feed water heater 8 located downstream. Exhaust gas from the incinerator 2 is introduced into the feed water heater 8, and the water from the condenser 7 is heated by heat exchange with the exhaust gas and then supplied to the heat transfer pipe 1 and upstream of the incinerator 2. Sent to the side again. In the heat utilization system 9, hot water cooled by supplying warm heat to the demand side is likewise supplied to the heat transfer tube 1 and returned to the incinerator 2.

The combustible waste is introduced into the variable pressure incinerator 2 through a waste supply device 11 which will be described later, and is burned to give combustion heat to the feed water in the heat transfer tube 1 and then to a low temperature. The exhaust gas is introduced into the feed water heater 8. As described above, the feed water from the condenser 7 is heated in the feed water heater 8 and then discharged to the atmosphere. On the other hand, the residue after combustion is partly accompanied by the exhaust gas and is collected by the exhaust gas dust collector 12 before being released to the atmosphere. The remaining residue after combustion is introduced into a discharge device 13 described later by a conveyor (not shown) installed in the incinerator 2.
From there, it is discharged to the outside of the incinerator 2.

FIG. 4 schematically shows the outline of the waste supply device 11. In the waste supply device 11, the waste introduction hopper 51 is located on the most upstream side, and the pressurization chamber 53 is connected to the downstream side of the waste introduction hopper 51 via a pressure resistant opening / closing valve 52. The pressurizing chamber 53 is provided with an appropriate pressurizing means (not shown), and the inside of the pressurizing chamber 53 is pressurized from atmospheric pressure to about 10 atmospheric pressure. The downstream side of the pressurizing chamber 52 is connected to a pressurized waste supply hopper 55 that is maintained at the same pressure as the pressure in the incinerator 2 via a pressure-resistant on-off valve 54. The discharge side of the pressurized waste supply hopper 55 is connected to the pressurized incinerator 2 via the screw feeder 56.

The waste, which is a combustion product, is crushed by a crushing means (not shown) on the upstream side of the waste introducing hopper 51, and then supplied to the waste introducing hopper 51. When a certain amount of pulverized waste is stored in the waste introduction hopper 51, the pressure resistant on-off valve 52 is opened and the pulverized waste is sent to the pressure chamber 52. Pressure resistant open / close valve 52
Is closed and the inside of the pressurizing chamber 53 is pressurized to a pressure slightly higher than the internal pressure of the pressurizing incinerator 2. After the pressurization, the second pressure-resistant on-off valve 54 is opened, and the pulverized waste in the pressurized state is sent into the pressurized waste supply hopper 55. Since the pressure inside the waste supply hopper 55 is maintained at the same pressure as the pressure inside the incinerator 2, the screw feeder 56 allows the pressurized waste to flow smoothly to the pressurized incinerator 2 without causing a so-called blowing phenomenon. Is supplied to.

FIG. 5 schematically shows the outline of the residue discharge device 13 after combustion. The residue discharge device 13 has the same configuration as the waste supply device 11 described above, but is configured such that, contrary to the case of the waste supply device 11, the most upstream side is the high pressure side and the downstream side is the atmospheric pressure. . That is, the incinerator 2 and the pressure chamber 62 are connected via the first pressure-resistant on-off valve 61.
Are connected to each other in an airtight manner, and the pressure chamber 62 is provided with an appropriate pressure reducing mechanism (not shown). Pressure chamber 62
Is connected to a discharge hopper 64 opened to the atmospheric pressure via a second pressure-resistant on-off valve 63, and the discharge hopper 64 is provided with a screw feeder 65.

The first pressure-resistant on-off valve 61 is opened with the second pressure-resistant on-off valve 63 closed, and the residue remaining after combustion in the incinerator 2 is introduced into the pressure chamber 62. Next, the pressure resistant on-off valve 61 is closed, the pressure in the pressure chamber 62 is reduced to the atmospheric pressure, and then the second pressure resistant on-off valve 63 is opened to discharge the combustion residue to the outside of the incinerator. By using the waste supply device 11 and the residual substance discharge device 13 having such a configuration, it becomes possible to safely operate the plant under the pressure fluctuating inside the incinerator 2.

Next, a method of operating a combined heat and power plant using the variable pressure combustion type incinerator according to the present invention will be described. Basically, this system selectively switches between the operation of the power supply main body and the operation of the heat supply main body according to the demand on the heat demand side. In the case of the operation mainly performed by the power supply, the inlet switching valve 5 is switched to the compressor 3 side to send the compressed air to the incinerator 2 to increase the pressure inside the incinerator 2 and to generate the steam in the heat transfer tube 1. Increase the amount,
Further, the outlet switching valve 10 is switched to the steam turbine 6 side, and the generated steam is introduced to generate power.

In the case of the operation mainly for supplying heat, the compressor 3 is stopped and the inlet switching valve 5 is switched to the pressure reducing pump 4 side so that the pressure inside the incinerator 2 becomes normal pressure or below normal pressure. The temperature is lowered and hot water or saturated steam is generated in the heat transfer tube 1. Further, the outlet switching valve 10 is switched to the heat utilization system 9 side, and hot water is generated or saturated steam is introduced to supply heat.

Hereinafter, each case will be described in detail. In winter, there is usually a large demand for heating, and as described above, operation is mainly performed by supplying heat. That is, the inlet switching valve 5 is switched to the pressure reducing pump 4 side to connect the inside of the incinerator and the pressure reducing pump 4, and the outlet switching valve 10 is switched to the heat utilization system 9 side. By the action of the decompression pump 4, the internal pressure of the incinerator 2 is set to the normal pressure or a set value equal to or lower than the normal pressure in advance to reduce the heat generation amount and lower the combustion temperature of the waste than usual. The feed water in the heat transfer tube 1 is heated while flowing in the incinerator 2 whose temperature has been raised by combustion to become hot water, which is introduced into the heat utilization system 9 by the outlet switching valve 10. The hot water after supplying the heat to the demand side by the heat utilization system 9 is reintroduced into the heat transfer tube 1.

On the other hand, when the demand for electric power for cooling in the summer is high, the electric power supply main operation is performed. In that case, the inlet switching valve 5 is switched to the compressor 3, and the outlet switching valve 10 is switched to the steam turbine 6. The air compressed by the compressor 3 is introduced into the incinerator 2 to increase the internal pressure and increase the calorific value to raise the combustion temperature of the waste. The feed water in the heat transfer tube 1 evaporates while flowing in the incinerator 2 whose temperature has risen.
The steam switching is performed by the outlet switching valve 10 after being overheated.
It is introduced into bin 6. By increasing the power supplied to the compressor 3, the pressure inside the incinerator 2 also increases proportionally, and the combustion temperature of the waste also rises. Therefore, the amount of steam generated in the heat transfer tube 1 also increases accordingly, and the amount of power for recovery of the steam turbine also increases.

The steam after the power is recovered in the steam turbine 6 is condensed in the condenser 7 and then introduced into the feed water heater 8 to recover heat from the exhaust gas from the incinerator 2. Then, it is introduced into the heat transfer tube 1. In winter, the outside temperature may be low and it may be difficult to start the plant. In such a case, the inlet switching valve 5 is switched to the pressure reducing pump 4 side, the internal pressure of the incinerator 2 is set to atmospheric pressure or below atmospheric pressure in advance, and the operation for lowering the combustion temperature of wastes is performed. . After the combustion is started, the waste combustion temperature in the incinerator 2 is gradually raised, the inlet switching valve 5 is switched to the compressor 3, and the internal pressure of the incinerator 2 is increased. By performing such operation,
It is possible to optimally adjust the rate of increase in the pressure inside the incinerator 2 and control the waste combustion temperature, reduce the thermal stress acting on the incinerator 2 and extend the life.

When performing such an operation, it is particularly effective to use, as the switching valve 5, one having a structure for distributing the pressure air from the compressor 3 to the compressor 3 side and the exhaust pump 4 side. Next, another embodiment of the present invention will be described with reference to FIG. Here, in order to avoid duplication of the description of FIG. 1, differences from FIG. 1 will be mainly described. That is, in this example, in addition to the components of the plant of FIG. 1, a flash evaporation type desalination apparatus 14 was installed at the heat supply destination of the heat utilization system 9. As a result, it was possible to use the heat obtained in the incinerator to produce tap water or tap water from the sewage and at the same time to concentrate the sewage.

In the operation of this plant, the inlet switching valve 5 is switched to the pressure reducing pump 4 side, and
The outlet switching valve 10 is switched to the heat utilization system 9 side. The hot water introduced into the heat utilization system 9 supplies only warm heat to the demand side through heat exchange. The supplied heat is introduced into the desalination apparatus 14 and serves as an operating heat source. Sewage is introduced into the desalination apparatus 14,
Water is flash-evaporated by heat at the ambient temperature, and then purified to produce clean water or clean water. On the other hand, the sewage whose water has been evaporated is concentrated and introduced into a sewage treatment facility.

In the above description, the outlet switching valve 1
The mode in which either the steam turbine 6 or the heat utilization system 9 is selectively used by switching 0 has been described, but both are operated so as to operate simultaneously in a partial load state according to the demand side demand. It is also possible. At that time, it is particularly effective to interpose an appropriate condenser in the path between the outlet switching valve 10 and the heat utilization system 9.

Further, although not particularly described in the embodiment, a sensor for measuring the pressure or the temperature of the heat transfer tube 1 at the outlet side of the incinerator is attached to the heat transfer tube, and further, an inlet switching valve is provided by a signal from the sensor. 5 or by adjusting the feed rate of the compressor 3, the incinerator 2
A control mechanism for maintaining the internal pressure at a predetermined value may be provided.When such waste is used as a combustible material, the waste is usually not constant in the amount of heat generated in the furnace. This is especially effective because the pressure in 1 tends to fluctuate.

Further, the waste is described as a combustible material because it can be effectively used especially when combusted by using an incinerator whose internal pressure can be adjusted. It will be readily understood that other than can be used. As described above, in the combined heat and power plant using the variable pressure combustion type incinerator and the method of operating the same according to the present invention, the combustion of the waste in the incinerator 2 is performed according to the quality of energy demand (heat or electricity). Since the temperature is adjusted, it is possible to operate under optimum conditions according to the demand side, and at the same time reduce the thermal stress applied to the main body of the incinerator 2 at the time of plant startup and extend the life. You can

[0030]

Since the present invention is constructed as described above, it has the following effects.
The incinerator is a container whose internal pressure can be adjusted, and by varying the internal pressure of the incinerator to arbitrarily adjust the combustion temperature of the waste, it is possible to change the amount of supplied power and heat according to the demand side demand. can do.

When there is a large demand for heating in winter, the internal pressure of the incinerator is set to normal pressure or below, the combustion temperature of the waste is lowered, and low-pressure steam is set in the heat transfer tube installed in the incinerator. Alternatively, it is possible to generate more hot water than during normal operation and supply it to the demand side. For example, when there is a large demand for electric power for cooling in the summer, the pressure inside the incinerator is increased to raise the combustion temperature of the waste, and the power to be recovered by the steam turbine is increased to the demand side. It is possible to increase the amount of electric power supplied to the incinerator, and adjust the internal pressure of the incinerator and control the waste combustion temperature at the time of plant startup when the outside temperature in winter is low, so that the thermal stress acting on the incinerator is increased. Can be reduced and the service life can be extended.

Further, a flash evaporation type desalination apparatus is added, and the warm heat obtained in the incinerator is used to produce tap water or tap water from the sewage, and at the same time, the sewage is concentrated to reduce the size of the sewage treatment facility. Can be converted.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a combined heat and power plant using a variable pressure combustion type waste incinerator of the present invention.

FIG. 2 is a system diagram showing another embodiment of the present invention.

FIG. 3 is a diagram showing the influence of heat generation amount on pressure.

FIG. 4 is a diagram showing a waste supply device.

FIG. 5 is a view showing a device for discharging combustion residues.

[Explanation of symbols]

1 ... Heat transfer tube 1, 2 ... Variable pressure type incinerator, 3 ... Compressor, 4 ... Decompression pump, 5 ... Inlet switching valve, 6 ... Steam turbine, 7 ... Condenser, 8 ... Feed water heater, 9 ... Heat utilization system, 10 ... Exit switching valve, 11 ... Flash evaporation desalination device

Claims (7)

[Claims] 1. A method of operating a combined heat and power plant, which uses an incinerator having a combustion vessel whose internal pressure is adjustable, to generate and supply electric power and warmth by using the heat of combustion of combustible materials, the quality of energy demand. A variable-pressure combustion type characterized in that the pressure in the incinerator is changed according to (heat or electric power) to arbitrarily adjust the combustion temperature of the combustible material, thereby making it possible to change the amount of electric power and heat supplied. Operation method of combined heat and power plant using incinerator. 2. When heating demand is high, the internal pressure of the incinerator is set to atmospheric pressure or lower, and the combustion temperature of the waste is lowered, and low-pressure steam is set in the heat transfer tube installed in the incinerator. Alternatively, the method for operating a combined heat and power plant using a variable pressure combustion type incinerator according to claim 1, characterized in that hot water is generated in a larger amount than during normal operation and is supplied to the demand side. 3. The thermal stress acting on the incinerator is reduced by adjusting the pressure in the incinerator and controlling the waste combustion temperature when the plant is started when the outside air temperature is low. A method for operating a combined heat and power plant using the variable pressure combustion type incinerator according to claim 2. 4. When the cooling power demand is high, the pressure inside the incinerator is increased to raise the combustion temperature of the waste,
The method for operating a combined heat and power plant using a variable pressure combustion type incinerator according to claim 1, wherein the power recovered by the steam turbine is increased to increase the amount of power supplied to the demand side. 5. The method of operating a combined heat and power plant using a variable pressure combustion type incinerator according to claim 1, wherein the combustible material is waste. 6. A variable pressure type incinerator having a heat transfer tube for recovering combustion heat of combustible substances to generate steam or hot water, a compressor and a pressure reducing pump for adjusting pressure in the incinerator, and switching between them. Inlet switching valve, steam turbine for recovering power from steam from the heat transfer tube, condenser for condensing steam after power recovery, and heat utilization system for utilizing heat of hot water from the heat transfer tube And an outlet switching valve for introducing steam or hot water from the heat transfer tube into the steam turbine or the heat utilization system, a combined heat and power plant having a variable pressure combustion type incinerator. 7. A desalination apparatus is further added to the heat utilization system that utilizes the heat of the hot water from the heat transfer tubes, whereby the warm heat obtained in the incinerator is used to change from sewage to tap water or gray water. The combined heat and power plant for variable pressure combustion type incinerator according to claim 6, characterized in that the sewage is concentrated at the same time that the sewage is manufactured to reduce the size of the sewage treatment facility.