WO2014017377A1

WO2014017377A1 - Exhaust gas power generation purification system

Info

Publication number: WO2014017377A1
Application number: PCT/JP2013/069507
Authority: WO
Inventors: 啓吾清水
Original assignee: Shimizu Keigo
Priority date: 2012-07-23
Filing date: 2013-07-18
Publication date: 2014-01-30
Also published as: JPWO2014017377A1; JP6007365B2

Abstract

An exhaust gas power generation purification system in which: exhaust gas is introduced using a blower into a turbine compartment which is rotated by the expansion power of high-temperature exhaust gas which has passed through a cyclone dust collection machine. A mist of urea water is atomized and vaporized into an entrance to the turbine compartment or the interior of the turbine compartment or both of these; the energy at the time of vaporization expansion of said mist within the turbine compartment is used in direct turbine driving to increase the rotary power of the turbine; the energy is retrieved by a connected motor for power-generating use; and said turbine exhaust air is sent in to a wet purification device where the exhaust gas is purified. After said vaporized mist has been condensed the minute dust which has been filtered by a filter is reused as mist for atomizing into said turbine, and is also atomized into a furnace or a flue. All or a part of the exhaust air expelled from the wet purification device is circulated back to the furnace and the exhaust air not circulated back is sent into an activated carbon adsorption column or said exhaust air is sent into an activated carbon adsorption column and all or a part of the exhaust gas to be expelled from said activated carbon adsorption column is circulated back to the furnace.

Description

Exhaust gas power generation purification system

The present invention combines a high-temperature exhaust gas purification process and power generation equipment in factories (including coke ovens), waste incineration facilities, sewage treatment facilities, etc., in addition to a method for efficient energy recovery (power generation) and regeneration cycle, The present invention relates to an exhaust gas purification method that does not require a wastewater treatment facility and a specific device used in a system that combines these methods.

Heat (energy) recovery of high-temperature exhaust gas discharged from factories (including coke ovens), waste incineration facilities, sewage treatment facilities, etc. is generally performed by a method that obtains hot water or steam using a hot water boiler or steam boiler. ing. In a large-scale facility, a steam turbine generator is driven by steam obtained from a steam boiler to recover exhaust heat. However, hot water and steam can be said to be an effective recovery method if there is demand within each plant facility, but if there is no demand, it will not be an effective recovery method, and steam turbine power generation is accompanied by boilers, condensers, etc. This is an effective recovery method when the cost of equipment and its operation is high and a large amount of electricity can be generated in a large-scale plant, but the cost performance is low for the amount of heat emitted from a relatively small-scale equipment. However, the current situation is that it has not been introduced into general equipment. In addition, there are designers who are designing exhaust heat turbine generators that utilize the expansion force of exhaust gas as special turbines, but they have not yet been introduced into general facilities in terms of cost performance. . In addition to this, as a prior art, the exhaust gas is increased by mist or steam and the turbocharger (turbo turbine) is driven to create compressed air, and this system is used as a combustion air to be sent to the combustion furnace Although there is technology to generate electricity by connecting a motor for power generation, it is a method of using a completely open type (back pressure type) working medium, and the main purpose is to create compressed air and control the pressurized flow furnace incinerator Because of the stabilization, the power generation and exhaust gas purification processes were separated, and the system was not directly aimed at efficient power generation. As for the purification of exhaust gas, although there are established technologies such as spray type and bubble type as a wet type purification device, advanced wastewater treatment equipment for treating waste liquid is necessary and well-equipped sewage treatment facilities etc. However, there is a problem that the cost of outsourcing the waste liquid treatment and the installation cost of the equipment increase in a factory that can be easily introduced but is not equipped with facilities.

JP2004-89776 (P2004-89776A) JP2004-92419 (P2004-92419A) JP2005-28251 (P2005-28251A) JP2007-170704A (P2007-170704A)

The method of driving a steam turbine using steam obtained from a steam boiler (heat exchanger, evaporator) is expensive to install and operate ancillary equipment, and also uses high-temperature (high-pressure) exhaust gas as mist. The method of generating electricity accompanying the generation of compressed air by generating turbines by increasing the amount of steam can achieve stable turbine efficiency if the amount of processing is large and constant (see the prior art document), but the amount of processing In both times, the turbine efficiency is significantly reduced and the cost performance with respect to the amount of power generation is not necessarily a satisfactory system. This method is not generally used as a power generation method using waste heat in facilities. In addition, these power generations always have a process of exhaust gas treatment, and in a system in which these processes and power generation are completely separated, there is a limit in achieving efficient heat recovery (power generation) and regeneration cycles. As for the purification of exhaust gas, although there are established technologies such as spray type and bubble type as a wet type purification device, advanced wastewater treatment equipment for treating waste liquid is necessary and well-equipped sewage treatment facilities etc. However, there is a problem that the cost of outsourcing the waste liquid treatment and the installation cost of the equipment increase in a factory that can be easily introduced but is not equipped with facilities.

Therefore, the present invention eliminates the need for an advanced wastewater treatment facility in addition to a method capable of performing energy recovery (power generation) and a regeneration cycle without requiring an expensive incidental facility such as a steam boiler or a condenser or a large scale. An exhaust purification method and a specific device used in a system combining these methods are provided.

The present invention employs the following means to achieve the above object. In other words, exhaust gas is introduced into the turbine casing that is rotated by the expansion force of the high-temperature exhaust gas that has passed through the cyclone dust collector using a blower (compressor), and urea water mist is introduced into the turbine casing inlet and / or the turbine casing. By spraying and vaporizing, and using the energy at the time of vaporization and expansion of the mist in the turbine casing directly for driving the turbine, the rotational force of the turbine is increased, and energy recovery (power generation) is performed by the connected power generation motor. Exhaust gas is sent to wet deodorization, desulfurization, denitration, and dust collection equipment (hereinafter referred to as wet purification equipment) to purify the exhaust gas, and after condensing the vaporized mist, fine dust is filtered by the filter into the turbine. Used again as a mist for spraying, spraying into the furnace or flue, one of the exhaust discharged from the wet purification device Alternatively, a part of the exhaust gas exhausted from the activated carbon adsorption tower by sending exhaust gas that has been refluxed entirely into the furnace and not refluxed to the activated carbon adsorption tower, or sending the exhaust gas (exhaust from the wet purification device) to the activated carbon adsorption tower Alternatively, the whole is refluxed into the furnace.

An impeller (turbine blade) having a blower (compressor) and rotating by the expansion force of the exhaust gas introduced thereby is held in the turbine casing, and mist is supplied to the turbine casing inlet or the turbine casing or both. A power generation apparatus having a structure and a function of spraying and having the turbine connected to a power generation motor by a shaft is produced.

The casing has an exhaust intake port and an exhaust port, and a space A extending from the intake port has an inner wall so as to gradually expand toward the lower part, a path from the space A toward the upper part along the inner wall, and a lower part of the space A It has a space B that is connected by a path that is inclined away from the space and heads upward, and the space B includes a plurality of small spaces that are configured to spray mist from above, and each small space has flowed into the space B. As the exhaust gas advances, it is connected with a relationship that sandwiches the ellipsoidal inner wall with a stepped upward direction, and it is filled with a guide plate that is inclined (curved) to change the direction of exhaust gas flow along the ellipsoidal inner wall The liquid to be discharged overflows in two stages, a filter and a discharge port are provided in the space where each overflow is received, and a mist sprayer is provided near the exhaust intake port. Making deodorization, desulfurization, denitrification, dust collector (hereinafter wet purification apparatus) to

It is possible to operate with relatively shorter start-up time than conventional steam power generation without the need for expensive auxiliary equipment such as a steam boiler (evaporator) and condenser (condenser, cooling equipment) Because it is not a complete back-pressure type, it ensures power generation efficiency comparable to conventional steam power generation, and generates compressed air by sending the exhaust gas increased by mist and steam to the turbine for additional power generation. Higher power generation efficiency than the method can be obtained.

Power generation using coal-fired power, LNG, and waste heat always has a process of exhaust gas treatment. In a system that completely separates these processes from power generation, there is a limit to the efficiency of heat circulation and heat recovery. However, by combining exhaust gas dust collection, deodorization, desulfurization, and denitration processes with a new power generator, efficient energy recovery (power generation) and regeneration cycles can be performed.

In conventional steam turbine power generation at large plants, etc., a condensate system is used to ensure an efficient power generation and regeneration cycle (the steam inside the condenser is evacuated by cooling it with a condenser and returning it to a liquid. However, in order to expand the steam to the exhaust pressure close to the vacuum in the turbine casing, it is necessary to enlarge the structure of the turbine casing and to withstand the vacuum. Although it is required and the manufacturing cost is also expensive, in this system, it is not necessary to install a bleeder because it is not a system aiming to keep it close to vacuum although it condenses steam with a wet purification device, There is no need to increase the size of the turbine casing and to make it expensive to withstand vacuum. In addition, although the turbine is exposed to high temperatures, the mist is always sprayed, so cooling of the blades is promoted by steam, and there is no need to use a heat-resistant special alloy as the turbine material. Can be easily manufactured with various specifications (selection of axial flow type, centrifugal type, number of stages, or screw type (rotary, roots type) turbine) is there. Even if a problem arises in heat resistance, it can be handled by coating with a ceramic heat insulating paint or the like, so that the turbine is inexpensive. However, since a phenomenon (effect) of drawing exhaust gas by the action of condensation can be obtained considerably, it is possible to generate power more efficiently than the back pressure type power generation method mainly used in small-sized and simple steam turbine power generation.

The wet purification apparatus according to claim 3 condenses the vapor by allowing the filling liquid to circulate in the counterclockwise direction in the drawing counterclockwise by the inflow of exhaust gas and efficiently cool it, but the condensed liquid has considerable residual heat. By spraying this to the turbine again, it is as efficient as the conventional condensate method in steam turbine power generation (no heat exchanger is used, the mist is sprayed to cool the working medium and promote condensation) As a matter of course, it is possible to obtain a more efficient regeneration cycle than that which promotes condensation by creating cold air externally and exchanging heat with the cold air using a heat exchanger. Since urea water is used as the working medium supplied and sprayed to the generator, the exhaust gas can be purified efficiently in a power generation process under high temperature and stirring conditions.

Since ammonia is generated from urea water sprayed as fine mist in a high-temperature turbine, ammonia and nitrogen oxides react and decompose into nitrogen and water. Unreacted nitrogen oxides and ammonia are sent directly to the activated carbon adsorption tower, where the reaction is accelerated by the catalytic action of the activated carbon and decomposed into nitrogen and water. As a result, the effects of both the non-catalytic reduction method and the activated carbon method (combined method) can be obtained in a series of processes, which is a measure for reducing leakage ammonia. Nitrogen oxide can be removed with high efficiency by the combined system and desulfurization can be performed in parallel, and since ammonia is intervened in the activated carbon adsorption tower, it is difficult to consume activated carbon during regeneration of the activated carbon. Economical operation is possible.

Nitrogen oxides generated by partially recirculating the exhaust gas purified in the system as combustion air to the combustion furnace can be suppressed, and efficiency is achieved by spraying the overflow of urea water in the wet purification device into the furnace or flue In addition, since the purification of nitrogen oxides is promoted, it is possible to reduce the concentration and amount of urea water newly supplied to the wet purification apparatus and to reduce the amount of urea water to be discarded as much as possible.

Even when desulfurization is involved, the waste discharged in a series of exhaust purification cycles is only leaked ammonia. (By using the used activated carbon for separate regeneration treatment as a maintenance, (Since sulfuric acid and ammonium sulfate are recovered as useful substances, the used activated carbon is not a waste ), and the concentration and amount of urea water to be supplied to the wet purification equipment by increasing the activated carbon adsorption tower or during operation By optimizing the system, it is relatively easy to clear the standard value of the amount and concentration of leaked ammonia, and since no separate neutralizer is used, it is possible to operate without generating sewage and to establish an advanced wastewater treatment facility. Because it is not necessary, not only sewage treatment facilities equipped with wastewater treatment facilities, but also high temperature exhaust gas from other factories (including coke ovens) and waste incineration facilities Also it can be installed operation of this system in the plant general to live.

Refer to the example (flow) in FIG.

Although it is a kind of turbine used for the power generator according to claim 2, it may be an axial flow, centrifugal turbine blade or the like that has been mainly used for power generation so far. Therefore, it is desirable to use a screw type, a rotary type, or a roots type in order to avoid an extremely low turbine efficiency. The type of the compressor (blower) is not limited in the same manner as described above. However, the compressor (blower) has a role of partitioning the compressor side and the turbine side of the power generation turbine to prevent backflow of fluid (working medium). It is desirable to use a screw type, a rotary type, or a roots type.

Embodiment of the whole system according to claim 1 (best mode) Specific example (schematic diagram) of the power generator according to claim 2 Specific example (schematic diagram) of the wet purification apparatus according to claim 3

Claims

The blower (compressor) is used to introduce exhaust gas into the turbine casing that is rotated by the expansion force of the high-temperature exhaust gas that has passed through the cyclone dust collector, and urea water mist is sprayed to the turbine casing inlet and / or the turbine casing Vaporizing and using the energy at the time of vaporization and expansion of the mist in the turbine casing directly for driving the turbine increases the rotational force of the turbine, and energy recovery (power generation) is performed by a connected power generation motor. For dehydration, desulfurization, denitration, and dust collection equipment (hereinafter referred to as wet purification equipment) to purify exhaust gas, condense the vaporized mist, and filter fine dust with a filter. Re-use as mist, spray into the furnace or flue, and part or all of the exhaust discharged from the wet-cleaning device Part of the exhaust gas exhausted from the activated carbon adsorption tower by sending exhaust gas that is refluxed into the furnace and not exhausted to the activated carbon adsorption tower, or sending the exhaust gas (exhaust gas discharged from the wet purification device) to the activated carbon adsorption tower Or collecting the deodorizing, desulfurizing, denitrating process and power generator of high-temperature exhaust gas from factories (including coke ovens), waste incineration facilities, sewage treatment facilities, etc. Exhaust purification methods that do not require advanced wastewater treatment facilities in addition to combined energy recovery (power generation) and regeneration cycles, and systems that combine these.
An impeller (turbine blade) having a blower (compressor) and rotating by the expansion force of the exhaust gas introduced thereby is held in the turbine casing, and mist is supplied to the turbine casing inlet or the turbine casing or both. A power generation apparatus having a structure and a function of spraying, wherein the turbine is connected to a power generation motor by a shaft.
The casing has an exhaust intake port and an exhaust port, and a space A extending from the intake port has an inner wall so as to gradually expand toward the lower part, a path from the space A toward the upper part along the inner wall, and a lower part of the space A It has a space B that is connected by a path that is inclined away from the space and heads upward, and the space B includes a plurality of small spaces that are configured to spray mist from above, and each small space has flowed into the space B. As the exhaust gas advances, it is connected with a relationship that sandwiches the ellipsoidal inner wall with a stepped upward direction, and it is filled with a guide plate that is inclined (curved) to change the direction of exhaust gas flow along the ellipsoidal inner wall The liquid to be discharged overflows in two stages, and a filter and a discharge port are provided in the space where each overflow is received, and a mist sprayer is provided near the exhaust intake port. Wet deodorization to, desulfurization, denitrification, dust collector.