A high-temperature exhaust gas to steam waste heat cascade utilization system and method

Abstract

The application provides a use method of a high-temperature waste gas to steam waste heat cascade utilization system. High-temperature waste gas discharged from a setting machine is filtered and impurity-removed in a waste gas conveying pipeline, enters a cascade heat exchange tube passage, is heat-exchanged in the cascade heat exchange tube passage, becomes low-temperature waste gas and is discharged. The application can collect the heat of high-temperature waste gas and convert it into clean high-temperature steam, which can be directly used or integrated into a steam pipe network. The heated cooling water can be used as a heat source of an air curtain machine of the setting machine, a cold air curtain protection room is provided at the inlet and outlet of the setting machine, indoor temperature is protected, and steam is saved. The waste heat gas discharge temperature can be greatly reduced, the internal water vapor discharge is reduced, and white smoke discharge is realized. The system has a self-cleaning heat exchange tube function, can clean the heat exchange passage without stopping and disassembling, and reduces manual maintenance cost. The system has a high and low temperature water waste heat recycling function, and maximally utilizes heat energy and water resources.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of printing and dyeing, textiles and the like, and in particular to a waste heat cascade utilization system and method for converting high-temperature waste gas into steam. BACKGROUND

[0002] In the field of printing and dyeing and textile industry, the heat recycling of high-temperature waste gas has always been a hot topic in the field. The existing waste gas recycling process generally uses cooling water immersion heat exchange, and then boils and vaporizes the high-temperature water to exchange heat with the high-temperature waste gas. This method has low heat exchange efficiency, and additional heat is consumed during the boiling process, which is not conducive to heat recovery. Due to the limitation of water cooling heat exchange, the water vapor contained in the waste gas cannot be effectively removed, resulting in the presence of white smoke during emission. Therefore, this method is not complete for waste gas heat recovery. In addition, the waste gas contains a large amount of greasy fluff and other impurities which are easy to deposit in the exhaust gas pipeline. The existing process technology can only disassemble and clean the pipeline, which is very troublesome. SUMMARY

[0003] The present application aims to provide a waste heat cascade utilization system and method for converting high-temperature waste gas into steam, which aims to solve the problems in the prior art.

[0004] The present application provides a waste heat cascade utilization system for converting high-temperature waste gas into steam. The high-temperature waste gas discharged from the setting machine is filtered and impurities are removed in the waste gas conveying pipeline, and then enters the cascade heat exchange pipe. After heat exchange in the cascade heat exchange pipe, the high-temperature waste gas becomes low-temperature waste gas and is discharged.

[0005] The cascade heat exchange pipe includes a primary spray heat exchange pipe and a multi-stage composite heat exchange pipe. High-temperature clean water is sprayed on the surface of the primary spray heat exchange pipe through which the high-temperature waste gas passes, and the high-temperature clean water is converted into primary water vapor through heat exchange with the high-temperature waste gas. The upper half of the multi-stage composite heat exchange pipe is a high-temperature water spray heat exchanger, and the lower half is a cooling water immersion heat exchanger. The secondary water vapor converted by the multi-stage composite heat exchange pipe spray heat exchanger and the primary water vapor are sucked into a flash separation tank through a compressor. The high-temperature water in the flash separation tank is directly flash vaporized and enters the user steam pipe network. The remaining water at the bottom of the tank is sucked into a water storage adjusting tank through a negative pressure pump for next time spraying.

[0006] The cooling water is heated by the multi-stage composite heat exchange pipe water immersion heat exchanger and then conveyed to the air curtain machine to exchange heat with the low-temperature air. The air curtain machine is installed on the inlet and outlet of the setting machine to provide a cold-proof hot air curtain protection room for the inlet and outlet of the setting machine, so as to save steam.

[0007] The self-cleaning injector is installed at the entrance of the exhaust passage of the primary spray heat exchange pipe and / or the exhaust passage of the multi-stage composite heat exchange pipe, and comprises a jet channel with a narrow throat and a washing liquid storage bottle below the narrow throat, the jet channel is communicated with the exhaust passage, a high-speed airflow is introduced into the exhaust passage from the jet channel, and the washing liquid in the washing liquid storage bottle is lifted under the action of pressure and enters the exhaust passage together with the airflow to wash and clean the inner wall of the exhaust passage.

[0008] Further, the high-temperature exhaust gas is first sprayed and humidified by the exhaust gas humidifier, and then enters the cyclone explosion-proof separator.

[0009] Further, the water surface in the sewage collection tank is higher than the bottom of the cyclone explosion-proof separator to form a water seal, so as to prevent exhaust gas leakage.

[0010] Further, a high-temperature probe is installed on the exhaust gas humidifier, the high-temperature probe is electrically connected with the electromagnetic valve of the spray fire extinguisher nozzle, and when the high-temperature exhaust gas enters the exhaust gas humidifier and causes static electricity to catch fire, the high-temperature probe sends a signal to control the electromagnetic valve to automatically open the spray fire extinguisher nozzle to implement large-flow spray fire extinguishing.

[0011] Further, when the remaining clean water in the flash separation tank accumulates to a certain height, the valve at the bottom of the flash separation tank is opened, and under the suction of the negative pressure pump, the clean water enters the water storage adjusting tank and is secondarily pressurized by the water pump to continue to be sprayed.

[0012] Further, the cooling water is heated by the multi-stage composite heat exchange pipe water immersion heat exchange, and then is transported to the air curtain machine to exchange heat with low-temperature air, and then is cooled by heat exchange and enters the water storage adjusting tank to be secondarily pressurized and heated to be used as the spray water of the multi-stage composite heat exchange pipe.

[0013] Further, a water supplement valve is installed at the water supplement opening of the water storage adjusting tank, and when the liquid level detector in the water storage adjusting tank detects a low water level, the water supplement valve is opened to automatically supplement water; when the liquid level detector detects a high water level, the water supplement valve is automatically closed.

[0014] The present application has the following advantages: the present application can collect a large amount of heat of high-temperature exhaust gas to be converted into clean high-temperature steam, which can be directly used or integrated into a steam pipe network; the heated cooling water can be used as the heat source of the air curtain machine of the setting machine, and a cold air curtain protection room is provided at the inlet and outlet of the setting machine to protect the indoor temperature, so that steam is saved; the exhaust gas discharge temperature can be greatly reduced, and the internal water vapor discharge is reduced, so that no white smoke is discharged; the system has the function of self-cleaning heat exchange pipe, and the heat exchange channel can be cleaned without stopping the machine and without disassembly, so that the labor maintenance cost is reduced; and the system has the function of high-temperature and low-temperature water waste heat recycling, so that the heat energy and water resources are maximally utilized. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present application.

[0016] Figure 2 It is a schematic diagram of the plane structure of the present application.

[0017] Figure 3 It is a schematic diagram of the side structure of the present application.

[0018] Figure 4 It is Figure 3 A-A cross-sectional view.

[0019] In the figure: 1, setting machine; 2, exhaust port; 3, waste gas humidifier; 4, cyclone explosion-proof separator; 5, sewage collection tank; 6, water tank sewage outlet; 7, primary spray heat exchange pipe; 8, high-temperature spray pipe; 9, compressor; 10, flash separation tank; 11, multi-stage composite heat exchange pipe; 12, suction pipe; 13, water storage adjusting tank; 14, waste gas exhaust port; 15, low-temperature spray; 16, air curtain machine; 17, self-cleaning injector. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] As Figures 1-4 shown in a high-temperature waste gas to steam waste heat cascade utilization system, comprising a gas heat recovery route and a water heat recovery route.

[0022] The gas heat recovery route mainly uses the high-temperature waste gas discharged by the setting machine. The high-temperature waste gas discharged by the setting machine 1 is first filtered and impurities are removed in the waste gas conveying pipeline, which includes a waste gas humidifier 3 and a cyclone explosion-proof separator.

[0023] The high-temperature waste gas is first sprayed and humidified by the waste gas humidifier 3 from the exhaust port 2 of the setting machine 1, and then enters the cyclone explosion-proof separator 4. After the impurities such as lint and oil sludge in the waste gas are soaked in water, their density increases, and under the centrifugal force of the cyclone explosion-proof separator 4, the impurities are separated and fall along the cylinder wall to the water-sealed sewage collection tank 5.

[0024] The water surface in the sewage collection tank 5 is higher than the bottom of the cyclone explosion-proof separator 4 to form a water seal to prevent waste gas leakage. After the sewage is collected to a certain extent, the valve at the bottom can be opened to discharge all the sewage through the water tank sewage outlet 6.

[0025] The high-temperature probe is electrically connected to the electromagnetic valve of the spray fire extinguisher nozzle. When the high-temperature probe sends a signal to control the electromagnetic valve to automatically open the spray fire extinguisher nozzle, the high-temperature waste gas entering the waste gas humidifier 3 causes static fire, and a large flow of spray fire extinguishing is implemented. In this way, the system can prevent the high-temperature waste gas from entering the waste gas humidifier 3 and causing a fire, ensuring the safety of the entire system.

[0026] The high-temperature waste gas with impurities removed enters the step-by-step heat exchange pipe. First, it enters the first-stage spray heat exchange pipe 7, which is provided with a waste gas passage. The high-temperature clean water is sprayed on the surface of the waste gas passage of the first-stage spray heat exchange pipe 7 through the high-temperature spray pipe 8. The high-temperature clean water rapidly vaporizes into first-stage water vapor when it comes into contact with the higher-temperature waste gas passage. The first-stage water vapor enters the flash separation tank 10 through the compressor 9 for temporary storage.

[0027] After the high-temperature waste gas is preliminarily heat exchanged in the first-stage spray heat exchange pipe 7, its temperature slightly decreases, and it immediately enters the multi-stage composite heat exchange pipe. In this embodiment, the multi-stage composite heat exchange pipe 11 adopts one stage, i.e., the second-stage composite heat exchange pipe. In practice, multiple stages can be designed according to needs. In this embodiment, the upper half of the second-stage composite heat exchange pipe is a high-temperature water spray heat exchange, and the lower half is a cooling water immersion heat exchange. That is, the upper half of the waste gas passage of the second-stage composite heat exchange pipe adopts a spray heat exchange, and the lower half is immersed in cooling water for a water immersion heat exchange. The high-temperature water spray heat exchange has the same principle as the first-stage spray heat exchange. The liquid level height is controlled by controlling the initial water volume to create an upper part that continues to generate steam to be collected and taken away, and a lower part that relies on gas-water heat exchange to achieve deep cooling of the waste gas to meet the discharge requirements. Finally, the waste gas is discharged from the system through the waste gas discharge outlet 14 and enters the user's steam header.

[0028] The water route heat recovery route includes the first-stage water vapor sprayed and vaporized in the first-stage spray heat exchange pipe 7, the second-stage water vapor sprayed and vaporized in the multi-stage composite heat exchange pipe 11, and the cooling water used for water immersion in the multi-stage composite heat exchange pipe 11.

[0029] The first-stage water vapor and the second-stage water vapor are sucked into the flash separation tank 10 through the suction pipe 12 by the compressor 9. The steam body enters the compressor 9 and is compressed and heated. The output temperature can be controlled by controlling the compressor speed through frequency conversion. Part of the high-temperature water in the flash separation tank 10 is flash vaporized and enters the user's steam pipe network. The remaining water falls to the bottom of the tank. When the height accumulates to a certain level, the electric valve opens, and the water is sucked into the water storage adjustment tank 13 through the negative pressure pump for the next spray use.

[0030] The water storage adjustment tank 13 is provided with a water supplement valve. When the liquid level detector in the water storage adjustment tank 13 detects a low water level, the water supplement valve opens to automatically supplement water. When the liquid level detector detects a high water level, the water supplement valve automatically closes.

[0031] The cooling water is heated by the multi-stage compound heat exchange pipe 11 water immersion heat exchange, and then is delivered to the air curtain machine 16 to exchange heat with low temperature air. The air curtain machine 16 is installed on the inlet and outlet of the setting machine 1, and provides a cold isolation hot air curtain protection room for the inlet and outlet of the setting machine 1, so as to save steam. The cooling water is cooled by heat exchange, and then enters the water storage adjusting tank 13. After being heated by secondary pressure, the cooling water is used as the spray water of the multi-stage compound heat exchange pipe 11 through the low temperature spray 15 pipe.

[0032] A self-cleaning injector 17 is installed at the inlet of the exhaust gas passage of the first-stage spray heat exchange pipe 7 and / or the multi-stage compound heat exchange pipe 11. The self-cleaning injector 17 comprises a jet passage with a narrow throat and a washing liquid storage bottle below the narrow throat. The jet passage is communicated with the exhaust gas passage, and a high-speed airflow is introduced into the exhaust gas passage from the jet passage. When passing through the narrow throat, the washing liquid in the washing liquid storage bottle rises under the action of pressure and enters the exhaust gas passage together with the airflow to flush and clean the inner wall of the exhaust gas passage.

[0033] It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the involved claims.

Claims

1. A method of using a high temperature exhaust gas to steam waste heat cascade utilization system, characterized in that, The high-temperature exhaust gas discharged from the setting machine is filtered and impurities are removed in the exhaust gas conveying pipeline, and then enters the cascade heat exchange tube, and becomes low-temperature exhaust gas after heat exchange and is discharged; The cascade heat exchange tube includes a primary spray heat exchange tube and a multi-stage composite heat exchange tube; high-temperature clean water is sprayed on the surface of the primary spray heat exchange tube through which the high-temperature exhaust gas passes, and the high-temperature clean water is converted into primary water vapor after heat exchange with the high-temperature exhaust gas; the upper half of the multi-stage composite heat exchange tube is a high-temperature water spray heat exchange, and the lower half is a cooling water immersion heat exchange, and the liquid level height is controlled by controlling the initial water quantity; the secondary water vapor converted by the multi-stage composite heat exchange tube spray heat exchange is sucked into a flash separation tank together with the primary water vapor through a compressor, the high-temperature water in the flash separation tank is directly flash vaporized and enters a user steam pipe network, and the remaining water falling to the bottom of the tank is sucked into a water storage adjusting tank through a negative pressure pump for next time spraying. The cooling water is heated by the multi-stage composite heat exchange tube water immersion heat exchange, and then is conveyed to an air curtain machine to exchange heat with low-temperature air, and then enters the water storage adjusting tank after heat exchange and cooling, and is used as spraying water of the multi-stage composite heat exchange tube after being heated by secondary pressure. A self-cleaning injector is installed at the exhaust gas passage inlet of the primary spray heat exchange tube and / or the multi-stage composite heat exchange tube; the self-cleaning injector includes a jet channel with a narrow throat and a washing liquid storage bottle below the narrow throat, the jet channel is connected with the exhaust gas passage, a high-speed airflow is introduced into the exhaust gas passage from the jet channel, and the washing liquid in the washing liquid storage bottle rises under the action of pressure and enters the exhaust gas passage together with the airflow to wash and clean the inner wall of the exhaust gas passage.

2. A method of using a high temperature exhaust gas to steam waste heat cascade utilization system according to claim 1, characterized in that, The high-temperature exhaust gas first sprays and moisturizes in the exhaust gas humidifier, and then enters the cyclone explosion-proof separator; the impurities in the humidified exhaust gas are separated and fall along the cylinder wall to the water seal sewage collection tank under the action of centrifugal force after being wetted.

3. A method of using a high temperature exhaust gas to steam waste heat cascade utilization system according to claim 2, characterized in that, The water surface in the sewage collection tank is higher than the bottom of the cyclone explosion-proof separator to form a water seal to prevent exhaust gas leakage.

4. A method of using a high temperature exhaust gas to steam waste heat cascade utilization system according to claim 3, characterized in that, A high-temperature probe is installed on the exhaust gas humidifier, the high-temperature probe is electrically connected with the electromagnetic valve of the spray fire extinguisher nozzle, and the high-temperature probe sends a signal to control the electromagnetic valve to automatically open the spray fire extinguisher nozzle to implement large-flow spraying and fire extinguishing when the high-temperature exhaust gas causes static electricity to catch fire.

5. A method of using a high temperature exhaust gas to steam waste heat cascade utilization system according to claim 1, characterized in that, When the remaining clear water in the flash separation tank accumulates to a certain height, the valve at the bottom of the flash separation tank is opened, and the clear water enters the water storage adjusting tank under the suction of the negative pressure pump to be pumped again for next time spraying.

6. A method of using a high temperature exhaust gas to steam waste heat cascade utilization system according to claim 1, characterized in that, A water supplement valve is installed at the water supplement port of the water storage adjusting tank, and the water supplement valve is opened for automatic water supplement when the liquid level detector in the water storage adjusting tank detects a low water level; the water supplement valve is automatically closed when the liquid level detector detects a high water level.

Images