Waste heat recycling system of RTO waste gas treatment device

Abstract

The utility model belongs to the technical field of RTO waste gas treatment devices, and particularly relates to a waste heat recycling system of an RTO waste gas treatment device. The waste heat recycling system of the RTO waste gas treatment device comprises an incinerator, two flues are arranged at a hearth of the incinerator, the top of the hearth is connected with a high-temperature flue gas filter set through a high-temperature flue gas pipeline, the high-temperature flue gas filter set is connected with a first-stage evaporator, the first-stage evaporator is connected with a superheater, and the superheater is connected with a second-stage evaporator. The second-stage evaporator is provided with a pipeline connected with a shell pass inlet of the high-temperature preheater, and a shell pass outlet of the high-temperature preheater is connected with a chimney. According to the waste heat recycling system of the RTO waste gas treatment device, full recycling of waste heat is achieved, the double-flue design improves the utilization rate of flue gas heat, various heat exchange pipes are designed in the device, the heat transfer efficiency is improved, and the running stability of the system is guaranteed due to the design of one open delivery pump and one standby delivery pump and filter set.

Description

Technical Field

[0001] This utility model belongs to the technical field of RTO waste gas treatment devices, specifically relating to a waste heat recovery and utilization system for an RTO waste gas treatment device. Background Technology

[0002] RTO (Regenerative Thermal Oxidizer) is a mature waste gas treatment technology that has been widely used in the industrial field. Its working principle is to use high-temperature oxidation to decompose organic waste gas into harmless carbon dioxide and water. This process generates a large amount of flue gas. In industrial production, the high-temperature flue gas emitted by RTO equipment (typically above 800℃) contains a significant amount of waste heat. Waste heat utilization mainly focuses on the following aspects: heat exchangers can transfer heat from the high-temperature waste gas to other media, such as air or water, allowing them to be heated for use in other processes or for domestic heating; Organic Rankine Cycle (ORC) technology can convert waste heat into electrical energy, achieving efficient energy utilization. However, traditional waste heat recovery devices have the following problems: low heat exchange efficiency, insufficient heat exchange between flue gas and working fluid, and inadequate waste heat utilization; complex structure, low system integration, large footprint, and difficult maintenance; poor operational stability, with some devices relying on forced circulation, resulting in high energy consumption and susceptibility to failure.

[0003] CN218120689U discloses an RTO waste gas treatment device with waste heat recovery and reuse. The waste heat recovery component of this device has a partition, heat conduction pipe, exhaust pipe, and air inlet pipe inside the chamber. The heat conduction pipe is surrounded by heat dissipation fins, as well as an activated carbon filter, a heat storage layer, and a temperature sensor. The waste heat recovery component can efficiently adsorb waste heat from RTO waste gas, which facilitates heat reuse, improves the waste gas treatment effect, and is energy-saving and environmentally friendly. However, it does not mention the treatment of impurities in the waste gas. If there are many impurities in the waste gas, it will affect the service life of the internal structure of the device and the waste heat recovery efficiency. Moreover, relying solely on temperature sensor monitoring may not be precise enough for the control of waste heat recovery.

[0004] CN222694304U discloses a waste heat recovery device for RTO exhaust gas treatment. A filter structure is installed at the exhaust gas inlet of the waste heat recovery box for RTO exhaust gas treatment. The filter screen filters impurities, the self-driven cleaning mechanism uses a scraper screw to clean the filter screen, and the slag discharge mechanism discharges debris. Through the filter structure, impurities can be filtered before the exhaust gas enters the recovery box, avoiding blockage and ensuring waste heat recovery efficiency. The self-driven cleaning and slag discharge functions ensure continuous exhaust gas flow and continuous waste heat recovery. However, it mainly focuses on exhaust gas filtration, and the waste heat recovery method is not described in detail, resulting in limited waste heat recovery effect. The filter structure increases the complexity of the device, leading to increased costs. Furthermore, the use of components such as the inclined slag motor increases energy consumption and maintenance costs.

[0005] Therefore, it is necessary to design a waste heat recovery and utilization system for RTO exhaust gas treatment devices to improve heat exchange efficiency and ensure the stability of device operation while maintaining a compact structure. Utility Model Content

[0006] The purpose of this utility model is to overcome the defects of the existing technology and provide a waste heat recovery and utilization system for RTO waste gas treatment device. The system achieves full recovery and utilization of waste heat through the coordinated operation of incinerator, multi-stage evaporator, preheater and various filters. At the same time, the dual flue design improves the utilization rate of flue gas heat. The internal design of the equipment has multiple heat exchange tubes to improve heat transfer efficiency. The design of one-on-one transfer pump and filter group ensures the stability of system operation.

[0007] The waste heat recovery and utilization system of the RTO waste gas treatment device of this utility model includes an incinerator. Two flues are provided in the furnace chamber of the incinerator. The top of the furnace chamber is connected to a high-temperature flue gas filter group via a high-temperature flue gas pipeline. The high-temperature flue gas filter group is connected to a primary evaporator. The primary evaporator is connected to a superheater, and the superheater is connected to a secondary evaporator. The secondary evaporator is provided with a pipeline connected to the shell-side inlet of a high-temperature preheater. The shell-side outlet of the high-temperature preheater is connected to a chimney. A middle section is provided in the middle of the incinerator furnace chamber. The high-temperature flue gas pipeline is connected to the medium-temperature flue gas filter group, which is connected to the shell-side inlet of the low-temperature preheater. The shell-side outlet of the low-temperature preheater is provided with a pipeline connected to the chimney. The tube-side inlet of the low-temperature preheater is connected to the transfer pump group, and the tube-side outlet of the low-temperature preheater is connected to the tube-side inlet of the high-temperature preheater. The tube-side outlet of the high-temperature preheater is provided with a pipeline connected to the secondary evaporator. The secondary evaporator is connected to the steam collector, and a pipeline returning to the superheater is provided at the top of the steam collector. The superheater is connected to the saturated steam pipeline.

[0008] Preferably, the delivery pump set is connected to the softened water tank, and the delivery pump set consists of two delivery pumps connected in parallel, with a control valve installed at the inlet of each delivery pump; furthermore, a level gauge is installed on the softened water tank.

[0009] Preferably, the primary evaporator has horizontally arranged finned heat exchange tubes inside, with air transported inside and high-temperature flue gas outside for heating the air inside the finned heat exchange tubes; the inlet of the primary evaporator finned heat exchange tubes is connected to an air pipeline, and the outlet of the primary evaporator finned heat exchange tubes is provided with a pipeline for returning to the incinerator inlet, which is connected to a fuel gas pipeline; furthermore, all welds of the finned heat exchange tubes are located on the outside.

[0010] Preferably, both the medium-temperature flue gas filter group and the high-temperature flue gas filter group consist of two filters connected in parallel, one in operation and one on standby.

[0011] Preferably, the superheater is provided with a serpentine pipe, the inlet of which is connected to the top outlet of the steam collector, and the outlet of which is connected to the saturated steam pipeline. The serpentine pipe is used to transport the saturated steam input from the steam collector to the superheater, and the superheater shell side is used to transport flue gas for flushing and heat transfer of the saturated steam.

[0012] Preferably, the secondary evaporator is equipped with horizontal pipes inside, with the tube side used to transport flue gas, the shell side inlet connected to the tube side outlet of the high-temperature preheater, and the shell side outlet connected to the steam collector, with the shell side used to transport steam.

[0013] Preferably, the steam collector is provided with a water tank at the bottom, and the water tank is provided with a pipeline for returning to the shell-side inlet of the secondary evaporator; a gas-liquid separator is provided at the top outlet of the steam collector for separating steam and condensate; furthermore, a pressure monitoring device is provided on the steam collector.

[0014] Preferably, the pump set consists of two pumps connected in parallel, and a control valve is installed at the inlet of each pump.

[0015] Preferably, the bottom of the primary evaporator, superheater, secondary evaporator and high-temperature preheater are all provided with drain ports, and the drain ports are all connected to the drain pipe.

[0016] The waste heat recovery and utilization system of the RTO waste gas treatment device has the following specific working process: Two flues are installed in the incinerator furnace. A flow guiding device is installed inside the furnace to divide the flue gas into upper and lower parts. When fuel burns in the furnace, it releases a large amount of heat, causing the gas temperature to rise rapidly. The high-temperature flue gas rises in the furnace and exits from the outlet at the top of the furnace. It then enters the high-temperature flue gas filter group through the high-temperature flue gas pipeline. After filtration, it enters the primary evaporator, where it exchanges heat with the air in the internal finned heat exchange tubes. The heated air then flows back to the incinerator for combustion support. The high-temperature flue gas flows sequentially through the heat exchanger and the secondary... The flue gas from the evaporator and the secondary evaporator enters the shell side of the high-temperature preheater. After heat exchange, the high-temperature flue gas is cooled to 150°C and finally discharged from the chimney. The flow guiding device inside the furnace is a horizontally arranged high-temperature resistant diversion baffle. Below the diversion baffle, multiple sets of arc-shaped flow guiding blades are evenly distributed. A special maintenance passage is set on the furnace wall, corresponding to the key components of the flow guiding device. Maintenance personnel can enter the furnace through this passage to inspect, clean, and maintain the flow guiding device. At the same time, a high-temperature resistant and well-sealed door is equipped at the passage opening to ensure that there is no flue gas leakage during normal operation.

[0017] In the central region of the furnace, the flue gas temperature is moderate due to both heat radiation from the combustion flame and the influx of some cold air to aid combustion. Under the guidance of the flow guiding device, the medium-temperature flue gas (300-350℃) enters the medium-temperature flue gas filter group through the medium-temperature flue gas pipeline, then enters the shell side of the low-temperature preheater, and is discharged through the chimney. Softened water in the softened water tank is supplied by a pump, and the control valve is regulated by signals such as steam pressure and water level in the softened water tank, achieving fully automatic operation. The softened water first enters the tube side of the low-temperature preheater, exchanges heat with the medium-temperature flue gas, and then enters the high-temperature preheater. The steam enters the shell side of the secondary evaporator from the tube side of the preheater. Due to the difference in density between steam and water, water accumulates at the bottom of the secondary evaporator. Steam overflows to the steam collector for collection and separation. Under the action of the gas-liquid separator at the top, the steam flows back to the inlet of the superheater's serpentine tubes. After being heated by the flue gas in the serpentine tubes, it is output from the saturated steam pipeline. The separated condensate accumulates in the water tank at the bottom of the steam collector and flows back to the shell side inlet of the secondary evaporator. In addition, the drain outlets at the bottom of the primary evaporator, superheater, secondary evaporator, and high-temperature preheater are regularly drained through the drain pipeline to ensure stable system operation.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows: The waste heat recovery and utilization system of the RTO waste gas treatment device of this utility model achieves full recovery and utilization of waste heat through the coordinated operation of incinerator, multi-stage evaporator, preheater and various filters. The first-stage evaporator preheats the air, raising the temperature of the combustion air, which is conducive to the full combustion of fuel in the incinerator and reduces fuel consumption. The flue gas filter group and the transfer pump group are designed with one on and one on standby to ensure stable treatment, reduce impurities and thermal pollution, and ensure the stable operation of the system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the waste heat recovery and utilization system of the RTO waste gas treatment device in this utility model.

[0020] In the diagram: 1. Incinerator; 2. Primary evaporator; 3. Superheater; 4. Secondary evaporator; 5. High-temperature preheater; 6. Low-temperature preheater; 7. High-temperature flue gas filter assembly; 8. Medium-temperature flue gas filter assembly; 9. Steam collector; 901. Water tank; 902. Gas-liquid separator; 10. Control valve; 11. Transfer pump; 12. Softened water tank; 13. Chimney; 14. Saturated steam pipeline; 15. Fuel gas pipeline; 16. Sewage pipeline; 17. Air pipeline. Detailed Implementation

[0021] The specific solution of this utility model will be further described below with reference to the accompanying drawings.

[0022] like Figure 1As shown: The waste heat recovery and utilization system of the RTO waste gas treatment device includes an incinerator 1, a primary evaporator 2, and a softened water tank 12. The top of the furnace of the incinerator 1 is connected to a high-temperature flue gas filter group 7 via a high-temperature flue gas pipeline. The high-temperature flue gas filter group 7 is connected to the primary evaporator 2. The primary evaporator 2 is connected to a superheater 3. The superheater 3 is connected to a secondary evaporator 4. The secondary evaporator 4 is provided with a pipeline connected to the shell-side inlet of a high-temperature preheater 5. The shell-side outlet of the high-temperature preheater 5 is connected to a chimney 13. The softened water tank 12 is connected to the tube-side inlet of a low-temperature preheater 6 via a transfer pump group. The tube-side outlet of the low-temperature preheater 6 is connected to the tube-side inlet of the high-temperature preheater 5. The tube-side outlet of the high-temperature preheater 5 is provided with a pipeline connected to the secondary evaporator 4. The secondary evaporator 4 is connected to a steam collector 9. The top of the steam collector 9 is provided with a pipeline returning to the superheater 3. The superheater 3 is connected to a saturated steam pipeline 14.

[0023] The first-stage evaporator 2 is equipped with finned heat exchange tubes arranged horizontally inside. The inlet of the finned heat exchange tubes of the first-stage evaporator 2 is connected to the air pipeline 17, and the outlet of the finned heat exchange tubes of the first-stage evaporator 2 is provided with a pipeline that returns to the inlet of the incinerator 1. The inlet of the incinerator 1 is connected to the fuel gas pipeline 15.

[0024] The incinerator 1 has a medium-temperature flue gas pipeline in the middle of the furnace that is connected to the medium-temperature flue gas filter group 8. The medium-temperature flue gas filter group 8 is connected to the shell inlet of the low-temperature preheater 6. The shell outlet of the low-temperature preheater 6 is provided with a pipeline that is connected to the chimney 13.

[0025] The medium-temperature flue gas filter group 8 and the high-temperature flue gas filter group 7 are each composed of two filters connected in parallel, one in operation and one on standby.

[0026] The superheater 3 is equipped with a serpentine pipe, the inlet of which is connected to the top outlet of the steam collector 9, and the outlet of which is connected to the saturated steam pipeline 14.

[0027] The secondary evaporator 4 is equipped with horizontal pipes inside. The inlet of the horizontal pipes is connected to the superheater 3, and the outlet of the horizontal pipes is connected to the shell-side inlet of the high-temperature preheater 5. The shell-side inlet of the secondary evaporator 4 is connected to the tube-side outlet of the high-temperature preheater 5, and the shell-side outlet of the secondary evaporator 4 is connected to the steam collector 9.

[0028] The steam collector 9 is equipped with a water tank 901 at the bottom, and the water tank 901 is equipped with a pipeline for returning to the shell inlet of the secondary evaporator 4; a gas-liquid separator 902 is installed at the top outlet of the steam collector 9.

[0029] The aforementioned pump set consists of two parallel pumps 11, and a control valve 10 is installed at the inlet of each pump 11.

[0030] The bottom of the primary evaporator 2, superheater 3, secondary evaporator 4 and high-temperature preheater 5 are all provided with drain ports, which are all connected to the drain pipe 16.

[0031] The waste heat recovery and utilization system of the RTO waste gas treatment device has the following specific working process: Two flues are installed in the furnace of incinerator 1. A flow guiding device is installed inside the furnace to divide the flue gas into upper and lower parts. When fuel burns in the furnace, it releases a large amount of heat, causing the gas temperature to rise rapidly. The high-temperature flue gas rises in the furnace and exits from the outlet at the top of the furnace. It then enters the high-temperature flue gas filter group 7 through the high-temperature flue gas pipeline. After filtration, it enters the first-stage evaporator 2, where it exchanges heat with the air in the internal finned heat exchange tubes. The heated air then flows back to incinerator 1 for combustion support. The high-temperature flue gas then flows sequentially through the superheater 3 and the second-stage evaporator... The flue gas from evaporator 4 and the secondary evaporator 4 enters the shell side of the high-temperature preheater 5. After heat exchange, the high-temperature flue gas is cooled to 150°C and finally discharged from the chimney 13. The flow guiding device inside the furnace is a horizontally arranged high-temperature resistant diversion baffle. Below the diversion baffle, multiple sets of arc-shaped flow guiding blades are evenly distributed. A special maintenance channel is set on the furnace wall, corresponding to the key components of the flow guiding device. Maintenance personnel can enter the furnace through this channel to inspect, clean, and maintain the flow guiding device. At the same time, a high-temperature resistant and well-sealed door is provided at the channel opening to ensure that there is no flue gas leakage during normal operation.

[0032] In the central region of the furnace, the flue gas temperature is moderate due to both the heat radiation from the combustion flame and the influx of some cold air to aid combustion. Under the guidance of the flow guiding device, the medium-temperature flue gas (300-350℃) enters the medium-temperature flue gas filter group 8 through the medium-temperature flue gas pipeline, then enters the shell side of the low-temperature preheater 6, and is discharged through the chimney 13. The softened water in the softened water tank 12 is supplied by the delivery pump 11. The control valve 10 is regulated by signals such as steam pressure and the water level in the softened water tank 12 to achieve fully automatic operation. The softened water first enters the tube side of the low-temperature preheater 6, exchanges heat with the medium-temperature flue gas, and then enters the high-temperature preheater. The steam enters the tube side of the preheater 5 and finally the shell side of the secondary evaporator 4. Due to the difference in density between steam and water, water accumulates at the bottom of the secondary evaporator 4. The steam overflows to the steam collector 9 for collection and separation. Under the action of the gas-liquid separator 902 at the top, the steam flows back to the inlet of the serpentine tube of the superheater 3. After being heated by the flue gas, it is output from the saturated steam pipe 14. The separated condensate accumulates in the water tank 901 at the bottom of the steam collector 9 and flows back to the shell side inlet of the secondary evaporator 4. In addition, the drain outlets at the bottom of the primary evaporator 2, superheater 3, secondary evaporator 4 and high-temperature preheater 5 will be drained regularly through the drain pipe 16 to ensure the stable operation of the system.

Claims

1. A waste heat recovery and utilization system for an RTO waste gas treatment device, characterized in that, The incinerator includes an incinerator (1), a primary evaporator (2), and a softened water tank (12). The top of the furnace of the incinerator (1) is connected to a high-temperature flue gas filter group (7) via a high-temperature flue gas pipeline. The high-temperature flue gas filter group (7) is connected to the primary evaporator (2). The primary evaporator (2) is connected to a superheater (3). The superheater (3) is connected to a secondary evaporator (4). The secondary evaporator (4) is provided with a pipeline connected to the shell-side inlet of a high-temperature preheater (5). The shell-side outlet of the high-temperature preheater (5) is connected to a chimney (13). The softened water tank (12) is connected to the inlet of the low-temperature preheater (6) via a delivery pump set. The outlet of the low-temperature preheater (6) is connected to the inlet of the high-temperature preheater (5). The outlet of the high-temperature preheater (5) is provided with a pipeline connected to the secondary evaporator (4). The secondary evaporator (4) is connected to the steam collector (9). The top of the steam collector (9) is provided with a pipeline for returning to the superheater (3). The superheater (3) is connected to the saturated steam pipeline (14).

2. The waste heat recovery and utilization system of the RTO waste gas treatment device according to claim 1, characterized in that, The first-stage evaporator (2) is equipped with finned heat exchange tubes horizontally inside. The inlet of the finned heat exchange tubes in the first-stage evaporator (2) is connected to the air pipeline (17). The outlet of the finned heat exchange tubes in the first-stage evaporator (2) is equipped with a pipeline that returns to the inlet of the incinerator (1). The inlet of the incinerator (1) is connected to the fuel gas pipeline (15).

3. The waste heat recovery and utilization system of the RTO waste gas treatment device according to claim 1, characterized in that, The incinerator (1) has a medium-temperature flue gas pipeline in the middle of the furnace connected to a medium-temperature flue gas filter group (8), the medium-temperature flue gas filter group (8) is connected to the shell inlet of the low-temperature preheater (6), and the shell outlet of the low-temperature preheater (6) is provided with a pipeline connected to the chimney (13).

4. The waste heat recovery and utilization system of the RTO waste gas treatment device according to claim 3, characterized in that, The medium-temperature flue gas filter group (8) and the high-temperature flue gas filter group (7) are both composed of two filters connected in parallel, with one filter on and one on standby.

5. The waste heat recovery and utilization system of the RTO waste gas treatment device according to claim 1, characterized in that, The superheater (3) is equipped with a serpentine pipe. The inlet of the serpentine pipe is connected to the top outlet of the steam collector (9), and the outlet of the serpentine pipe is connected to the saturated steam pipeline (14).

6. The waste heat recovery and utilization system of the RTO waste gas treatment device according to claim 1, characterized in that, The secondary evaporator (4) is equipped with horizontal pipes inside. The inlet of the horizontal pipes is connected to the superheater (3), and the outlet of the horizontal pipes is connected to the shell-side inlet of the high-temperature preheater (5). The shell-side inlet of the secondary evaporator (4) is connected to the tube-side outlet of the high-temperature preheater (5), and the shell-side outlet of the secondary evaporator (4) is connected to the steam collector (9).

7. The waste heat recovery and utilization system of the RTO waste gas treatment device according to claim 6, characterized in that, The steam collector (9) is provided with a water tank (901) at the bottom, and the water tank (901) is provided with a pipeline for returning to the shell inlet of the secondary evaporator (4); a gas-liquid separator (902) is provided at the top outlet of the steam collector (9).

8. The waste heat recovery and utilization system of the RTO waste gas treatment device according to claim 1, characterized in that, The pump set consists of two pumps (11) connected in parallel, and a control valve (10) is installed at the inlet of each pump (11).

9. The waste heat recovery and utilization system of the RTO waste gas treatment device according to claim 1, characterized in that, The bottom of the primary evaporator (2), superheater (3), secondary evaporator (4) and high-temperature preheater (5) are all provided with drain ports, which are all connected to the drain pipe (16).

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