Device for recycling waste heat of high-temperature flue gas of air cushion furnace

Abstract

The utility model relates to a device for recycling waste heat of high-temperature smoke of an air cushion furnace, which comprises a smoke exhaust fan pipeline of a heating section of the air cushion furnace and a boiler water return pipeline, a heat exchange assembly is connected between the boiler water return pipeline and the smoke exhaust fan pipeline, and the heat exchange assembly comprises a heat exchanger. A hot fluid channel of the heat exchanger is connected with a smoke exhaust fan pipeline. A cold fluid channel of the heat exchanger is connected with a boiler water return pipeline. A heat exchanger is additionally arranged between original smoke exhaust fan pipelines for waste heat recovery, the heat exchanger is connected with a nearby boiler return water pipeline, boiler return water serves as a water inlet cold end section of the heat exchanger, then a hot end returns to boiler return water, interconnection with an original system is achieved, and therefore energy consumption of a heating boiler system is reduced. Waste heat of flue gas of the air cushion furnace is effectively recycled to heat return water of the boiler, energy conservation and consumption reduction are achieved, and the purpose of sustainable development is achieved. The transformation method is scientific in principle, the implementation scheme is simple and easy to implement, and the waste heat recovery effect is good.

Description

Technical Field

[0001] This utility model relates to a device for recovering and utilizing the waste heat of high-temperature flue gas from an air cushion furnace. Background Technology

[0002] First, the automotive panel workshop requires a large amount of heat energy during the production process. The heating boiler heats water by burning fuel to produce steam or hot water, providing the necessary heat energy support for the workshop and ensuring the normal operation of the production line.

[0003] For example, the heating boiler in Ruimin Company's automotive panel workshop consumes 40,000-50,000 cubic meters of natural gas per month. Based on a 30-day, 24-hour production schedule, the actual average heating power of the boiler, W1, is calculated as follows: W1 = 40,000 (monthly natural gas consumption) * 35,588 * 90% (boiler efficiency) / 24 (hours) / 30 (days) / 3600 (seconds) ≈ 500kW. The boiler outlet water temperature is set to 97℃, with an actual outlet water temperature of 93-97℃ and a return water temperature of 80-84℃ (calculated based on an average of 82℃; the temperature difference between the return water and the heat exchanger exhaust should be calculated at least 10℃, i.e., 92℃). The continuous annealing line and the surface treatment line share a circulating pump with a nameplate flow rate of 300 m³ / h. Therefore, the maximum return water flow of the continuous annealing line is 150 m³ / h, with an actual operating flow rate of approximately 50-100 m³ / h.

[0004] In summary, the heating boiler in the automotive panel workshop requires a large amount of natural gas to heat the water.

[0005] Secondly, the flue gas temperature of the gas cushion furnace is approximately 250-300℃ (calculated based on 250℃). Based on the natural gas consumption of the gas cushion furnace, the amount of flue gas emitted can be calculated, and the usable waste heat is approximately:

[0006] W2 = Exhaust gas mass flow rate * flue gas temperature difference * flue gas specific heat * flue gas utilization rate =

[0007] [10000*273 / (273+250)*1.2]*(250-92)*1.01*85% / 3600≈236kW.

[0008] In summary, existing devices cannot recover and utilize waste heat, resulting in a significant waste of energy.

[0009] Therefore, in order to realize the waste heat recovery and utilization of the high-temperature flue gas of the air cushion furnace, and in order to reduce the amount of natural gas consumed by the heating boiler in the automotive panel workshop, this case proposes a device for waste heat recovery and utilization of the high-temperature flue gas of the air cushion furnace, and carries out waste heat recovery modification to achieve energy saving and consumption reduction. Utility Model Content

[0010] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide a device for recovering and utilizing the waste heat of high-temperature flue gas from an air cushion furnace.

[0011] In order to solve the above technical problems, the technical scheme of the utility model is: a device for waste heat recovery and utilization of high-temperature flue gas of an air cushion furnace, comprising a flue gas exhaust fan pipeline of a heating section of the air cushion furnace and a boiler backwater pipeline, a heat exchange assembly is connected between the boiler backwater pipeline and the flue gas exhaust fan pipeline, the heat exchange assembly comprises a heat exchanger, a hot fluid passage of the heat exchanger is connected with the flue gas exhaust fan pipeline, and a cold fluid passage of the heat exchanger is connected with the boiler backwater pipeline.

[0012] Preferably, the inlet of the hot fluid passage is a flue gas inlet, and the outlet of the hot fluid passage is a flue gas outlet.

[0013] Preferably, a flue gas inlet pipe is connected to the flue gas inlet, a flue gas outlet pipe is connected to the flue gas outlet, a flue gas bypass valve, a pressure sensor and a flue gas inlet temperature sensor are sequentially arranged on the flue gas inlet pipe along the flue gas flow direction, and a flue gas outlet temperature sensor and a flue gas exhaust fan are sequentially arranged on the flue gas outlet pipe along the flue gas flow direction.

[0014] Preferably, a flue gas branch pipe is connected between the flue gas inlet pipe and the flue gas outlet pipe, one end of the flue gas branch pipe is connected to the flue gas inlet pipe in front of the flue gas bypass valve, the other end of the flue gas branch pipe is connected to the flue gas outlet pipe between the flue gas outlet temperature sensor and the flue gas exhaust fan, and a flue gas exhaust valve and an air mixing valve are sequentially arranged on the flue gas branch pipe along the flue gas flow direction.

[0015] Preferably, the inlet of the cold fluid passage is a water inlet, and the outlet of the cold fluid passage is a water outlet.

[0016] Preferably, a water inlet pipe is connected to the water inlet, and a water outlet pipe is connected to the water outlet.

[0017] Preferably, a circulating pump and a water inlet temperature sensor are sequentially arranged on the water inlet pipe along the water flow direction, and a water outlet temperature sensor and an electromagnetic flowmeter are sequentially arranged on the water outlet pipe along the water flow direction.

[0018] Preferably, the other end of the water inlet pipe is connected to the boiler backwater pipeline, and the other end of the water outlet pipe is connected to the boiler backwater pipeline.

[0019] Preferably, the number of the circulating pumps is two.

[0020] Preferably, the two circulating pumps are arranged in parallel on the water inlet pipe.

[0021] Compared with the prior art, the utility model has the following beneficial effects: the utility model mainly adds a set of heat exchanger between original smoke exhaust fan pipeline to recover waste heat, heat exchanger connects nearby boiler backwater pipeline, takes boiler backwater as the water inlet cold end section of heat exchanger, then hot end returns to boiler backwater, realizes and the interconnection of original system, thereby reduces heating boiler system energy consumption. Through effectively recovering the waste heat of air cushion furnace flue gas to heat boiler backwater, realize energy saving and consumption reducing, achieve the purpose of sustainable development. The reconstruction method provided by the present application has scientific principle, and the implementation scheme is simple and easy to operate, and the waste heat recovery effect is good.

[0022] The utility model will be explained further in combination with the specific embodiment and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the structure schematic diagram of the utility model embodiment.

[0024] In the drawing: smoke exhaust fan pipeline 1, boiler backwater pipeline 2, heat exchanger 3, flue gas inlet pipe 4, flue gas outlet pipe 5, flue gas bypass valve 6, flue gas inlet temperature sensor 7, flue gas outlet temperature sensor 8, flue gas exhaust fan 9, flue gas branch pipe 10, flue gas exhaust valve 11, air mixing valve 12, water inlet pipe 13, water outlet pipe 14, circulating pump 15, water inlet temperature sensor 16, water outlet temperature sensor 17, electromagnetic flowmeter 18, pressure sensor 19. DETAILED DESCRIPTION

[0025] The utility model will be explained further in combination with the specific embodiment and the accompanying drawings.

[0026] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains.

[0027] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form, and in addition, it should be understood that when the terms "comprise" and / or "include" are used in the specification, they mean the presence of a feature, step, operation, device, component and / or combination thereof.

[0028] As Figure 1As shown, the embodiment provides a device for waste heat recovery of high-temperature flue gas of a gas cushion furnace, which is used for equipment modification of an exhaust fan pipeline of a heating section of a continuous annealing line gas cushion furnace, and comprises an exhaust fan pipeline 1 of the heating section of the gas cushion furnace and a boiler backwater pipeline 2, a heat exchange assembly is connected between the boiler backwater pipeline and the exhaust fan pipeline, the heat exchange assembly comprises a heat exchanger 3, a hot fluid passage of the heat exchanger is connected with the exhaust fan pipeline, and a cold fluid passage of the heat exchanger is connected with the boiler backwater pipeline.

[0029] The heat exchanger is used for applying high-temperature flue gas heat energy discharged from the heating section to heat supply backwater, and the heat supply backwater is returned to heat supply feed water after heating, so that the boiler water heating energy consumption is reduced.

[0030] In the embodiment of the utility model, the inlet of hot fluid passage is smoke gas inlet, the outlet of hot fluid passage is smoke gas outlet.

[0031] In the embodiment of the utility model, the smoke gas inlet pipe 4 is connected to the smoke gas inlet, the smoke gas outlet pipe 5 is connected to the smoke gas outlet, and the smoke gas inlet pipe and the smoke gas outlet pipe form the exhaust fan pipeline.

[0032] The smoke gas inlet pipe is sequentially provided with a smoke gas bypass valve 6, a pressure sensor 19 and a smoke gas inlet temperature sensor 7 along the smoke gas flow direction, and the smoke gas outlet pipe is sequentially provided with a smoke gas outlet temperature sensor 8 and a smoke gas exhaust fan 9 along the smoke gas flow direction.

[0033] In the embodiment of the utility model, the smoke gas branch pipe 10 is connected between the smoke gas inlet pipe and the smoke gas outlet pipe, one end of the smoke gas branch pipe is connected to the smoke gas inlet pipe in front of the smoke gas bypass valve, the other end of the smoke gas branch pipe is connected to the smoke gas outlet pipe between the smoke gas outlet temperature sensor and the smoke gas exhaust fan, and the smoke gas branch pipe is sequentially provided with a smoke gas exhaust valve 11 and an air mixing valve 12 along the smoke gas flow direction.

[0034] The smoke gas bypass valve, the smoke gas exhaust valve and the air mixing valve are used for controlling smoke gas exhaust, the smoke gas bypass valve is opened, the smoke gas exhaust valve is closed, and the air mixing valve is closed to indicate that the smoke gas passes through the smoke gas heat exchanger device, otherwise, the smoke gas is discharged from the original smoke gas pipeline without passing through the heat exchanger.

[0035] In the embodiment of the utility model, the inlet of cold fluid passage is water inlet, and the outlet of cold fluid passage is water outlet.

[0036] In the embodiment of the utility model, the water inlet pipe 13 is connected to the water inlet, and the water outlet pipe 14 is connected to the water outlet.

[0037] In the embodiment of the utility model, the water inlet pipe is connected with the boiler backwater pipeline at the other end, and the water outlet pipe is connected with the boiler backwater pipeline at the other end.

[0038] The electromagnetic flow meter is used for measuring the flow of liquid with conductive property, has flow accumulation function, controls flow and pressurizes, is used for measuring and controlling the flow of water, and is designed to have a flow of 80 m 3 / h.

[0039] In the embodiment of the utility model, the water inlet pipe is connected with the boiler backwater pipeline at the other end, and the water outlet pipe is connected with the boiler backwater pipeline at the other end.

[0040] In the embodiment of the utility model, the number of the circulating pumps is two.

[0041] In the embodiment of the utility model, the two circulating pumps are arranged in parallel on the water inlet pipe, one is used and the other is standby, so that one of them can run when in use, and the water from the boiler backwater pipeline is transported to the heat exchanger.

[0042] In the embodiment of the utility model, the working principle of the device for recovering and utilizing the waste heat of the high-temperature flue gas of the pair of air cushion furnaces is as follows:

[0043] The present application mainly adds a heat exchanger between the original exhaust fan pipeline for waste heat recovery, the heat exchanger is connected with the nearby boiler backwater pipeline, the boiler backwater is taken as the inlet cold end section of the heat exchanger, and then the hot end returns to the boiler backwater, so that the interconnection with the original system is realized, thereby reducing the energy consumption of the heating boiler system.

[0044] Before the heat exchanger is started (the flue gas emission temperature needs to be greater than 100 DEG C), the operator checks that the manual valves of the circulating water pipeline are normally opened, and the circulating pump is started to ensure that the water circulates for 60-180 s, then the flue gas bypass valve is opened, and after the flue gas enters the heat exchanger, the flue gas emission valve and the air mixing valve are closed, and the flue gas enters the heat exchanger for energy-saving waste heat utilization.

[0045] The waste heat of the flue gas of the air cushion furnace is effectively recovered to heat the boiler backwater, energy saving and consumption reduction are realized, and the sustainable development purpose is achieved.

[0046] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in other forms, and any skilled person in the art can modify or change the above disclosed technical content to equivalent embodiments with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiments without departing from the technical solution of the present application, and in accordance with the technical essence of the present application, still belong to the protection scope of the technical solution of the present application.

Claims

1. A device for waste heat recovery and utilization of high-temperature flue gas from an air cushion furnace, comprising an exhaust fan duct for the heating section of the air cushion furnace and a boiler return water duct, characterized in that: A heat exchange assembly is connected between the boiler return water pipe and the flue gas fan pipe. The heat exchange assembly includes a heat exchanger. The hot fluid channel of the heat exchanger is connected to the flue gas fan pipe, and the cold fluid channel of the heat exchanger is connected to the boiler return water pipe.

2. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 1, characterized in that: The inlet of the hot fluid channel is the flue gas inlet, and the outlet of the hot fluid channel is the flue gas outlet.

3. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 2, characterized in that: The flue gas inlet is connected to a flue gas inlet pipe, and the flue gas outlet is connected to a flue gas outlet pipe. A flue gas bypass valve, a pressure sensor, and a flue gas inlet temperature sensor are sequentially arranged on the flue gas inlet pipe along the flue gas flow direction. A flue gas outlet temperature sensor and a flue gas exhaust fan are sequentially arranged on the flue gas outlet pipe along the flue gas flow direction.

4. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 3, characterized in that: A flue gas branch pipe is connected between the flue gas inlet pipe and the flue gas outlet pipe. One end of the flue gas branch pipe is connected to the flue gas inlet pipe in front of the flue gas bypass valve, and the other end of the flue gas branch pipe is connected to the flue gas outlet pipe between the flue gas outlet temperature sensor and the flue gas exhaust fan. A flue gas exhaust valve and an air mixing valve are sequentially installed on the flue gas branch pipe along the flue gas flow direction.

5. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 1, characterized in that: The inlet of the cold fluid channel is a water inlet, and the outlet of the cold fluid channel is a water outlet.

6. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 5, characterized in that: A water inlet pipe is connected to the water inlet, and a water outlet pipe is connected to the water outlet.

7. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 6, characterized in that: A circulation pump and a water inlet temperature sensor are sequentially installed on the water inlet pipe along the water flow direction, and a water outlet temperature sensor and an electromagnetic flow meter are sequentially installed on the water outlet pipe along the water flow direction.

8. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 6, characterized in that: The other end of the water inlet pipe is connected to the boiler return water pipe, and the other end of the water outlet pipe is connected to the boiler return water pipe.

9. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 7, characterized in that: The number of circulating pumps is two.

10. The apparatus for recovering waste heat from high-temperature flue gas of an air cushion furnace according to claim 9, characterized in that: Two circulating pumps are connected in parallel on the water inlet pipe.

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