CN107014213A - Heat accumulating type used for industrial furnace impacts heat transfer unit (HTU) - Google Patents

Abstract

The invention discloses a regenerative impingement heat transfer device for an industrial furnace, which comprises a gas processing device, an air extraction pipeline and an air blowing pipeline are respectively arranged at the air extraction port and the air outlet of the gas processing device; The second air extraction branch, on the air blowing pipeline, the first and second air blowing branches are respectively set; the first air extraction branch and the first air blowing branch, the second air extraction branch and the second air blowing branch The pipelines are respectively connected with the first and second thermal accumulators in a controlled state, and the pipelines behind the first and second thermal accumulators are respectively provided with openings, which are used as outlets for extracting air or inlets for air intake. In the regenerative high-speed impact heat transfer industrial furnace of the present invention, the flue gas passes through the heat exchange of the regenerator to make full use of heat energy, and at the same time, the temperature of the flue gas heated by the regenerator is still suitable for directly spraying on the workpiece to be heated to directly heat the workpiece , Significantly improved the heat transfer coefficient; significantly improved the heating efficiency, increased by 20% or even higher on the basis of the original regenerative combustion, and improved uniformity.

Description

Regenerative impact heat transfer device for industrial furnace

technical field

The invention relates to an accessory part of an industrial furnace, in particular to a regenerative impingement heat transfer device for an industrial furnace using natural gas, liquefied gas, etc. as fuel.

Background technique

The industrial furnace using natural gas, coal gas or fuel oil as fuel, its working principle is to place the workpiece to be heated in the furnace, heat up to the temperature required by the process, keep warm or evenly temperature. In heating processes, it is generally accepted that there are three forms of heat transfer: radiation, convection, and conduction heating.

In the low temperature stage at the beginning of heating, the heat transfer is mainly by convection, and there is basically no radiation heat transfer, or the radiation heat transfer effect is very poor. At this stage, the heat exchange capacity between the workpiece to be heated and the furnace gas placed in the furnace is relatively poor, resulting in heating. low productivity. It is precisely because of the poor convective heat transfer capability at the beginning of heating, taking the forging industrial furnace as an example, its heating efficiency is very low, usually within 10%, some even only 3-5%, and the energy waste is serious; After combustion, the thermal efficiency is increased to about 30-50%, which has greatly improved the thermal efficiency, but it has basically reached the limit recovery rate of waste heat of regenerative industrial furnaces at the present stage, and it is difficult to improve the heating efficiency.

Due to the high temperature of fuel combustion, such as natural gas flames reaching above 2000°C, if such a high-temperature flame is directly sprayed on the workpiece to be heated, it will burn the workpiece, soften or partially melt the workpiece, and cause adverse effects on the internal structure of the workpiece. Changes, affecting performance or even greatly reducing its related performance indicators, so it is necessary to avoid direct spraying of the flame on the workpiece to be heated, so there are not many means to improve convective heat transfer in the existing technology. This is the main reason why the convective heat transfer heating efficiency is very low in the low temperature stage.

Although high-speed burners can be used now, the flame of the high-speed burner must be avoided from being directly sprayed on the workpiece to be heated. Generally, the workpiece to be heated is supported and kept away from the flame. For high-temperature furnaces, flat-flame combustion is usually used, which directly or indirectly reduce the convective heat transfer effect, and the convective heat transfer coefficient is still very low, resulting in longer heating time and more fuel consumption.

How to improve the convective heat transfer coefficient and greatly improve the heating efficiency of industrial furnaces without the high-temperature flame being directly sprayed on the workpiece to be heated, so as to shorten the heating time, reduce fuel consumption, and improve the temperature and gas uniformity in the furnace, It is a technical problem that this field wants to solve urgently.

Contents of the invention

The invention aims at the deficiencies in the heating process of industrial furnaces in the prior art, such as low heating efficiency, prolonged heating time, and increased fuel consumption due to low convective heat transfer coefficient, and provides an industrial furnace that greatly improves heating efficiency. Regenerative impingement heat transfer device for furnace.

The technical solution of the present invention: a regenerative impingement heat transfer device for industrial furnaces, characterized in that it includes a gas processing device for pressurizing the gas, and the gas extraction pipeline and the gas blowing pipeline are respectively arranged at the gas extraction port and the gas outlet of the gas processing device. Air port; on the air extraction pipeline, the first air extraction branch and the second air extraction branch are respectively set, and on the air blowing pipeline, the first air blowing branch and the second air blowing branch are respectively set; the first air extraction branch The first air blowing branch and the first air blowing branch are respectively communicated with the first heat accumulator under controlled conditions, and a first opening is provided on the pipeline behind the first heat accumulator, which is used as an exhaust outlet for air extraction or an air inlet for air intake; The second air extraction branch and the second air blowing branch are respectively in communication with the second heat storage body under controlled conditions, and a second opening is arranged on the pipeline behind the second heat storage body as a discharge port for air extraction or Air inlet.

A further feature is that nozzles are provided on the first opening and the second opening, and the cross-section of the nozzles is gradually reduced.

The controlled state is to set control valves on the first air extraction branch, the second air extraction branch, the first air blowing branch, and the second air blowing branch to switch each branch, Form a circulation pipeline with one way of air intake and the other way of exhaust.

On each branch pipeline, an automatic reversing valve and/or a manual control valve are respectively set.

The automatic reversing valves on two or four branches are set in linkage, and they act at the same time, and control the on-off of two or four branches at the same time.

On the pipeline between the first opening and the first heat storage body, a first gas collection box is arranged, and on the pipeline between the second opening and the second heat storage body, a second gas collection box is arranged.

On the pipeline between the first opening and the first heat storage body, or on the first gas collection box, a supplementary gas channel is set; on the pipeline between the second opening and the second heat storage body, or the second gas collection box On the box, set the supplementary gas channel.

An auxiliary air intake pipe is provided on the suction pipe.

A supplementary heat burner is also provided. The supplementary heat burner communicates with the first opening or the second opening respectively. A fuel feed pipe and a combustion-supporting gas inlet pipe are arranged on the supplementary heat burner. Under controlled conditions, the required fuel, Combustion-supporting gas passes through the fuel feed pipe and combustion-supporting gas inlet pipe respectively into the supplementary heating burner, and then passes into the furnace.

There are two gas processing devices, the first gas processing device is connected in series with the second gas processing device, the pumping pipeline is connected to the inlet of the first gas processing device, and the outlet pipe of the first gas processing device The outlet of the second gas processing device is directly connected to the inlet of the second gas processing device, and the outlet of the second gas processing device is connected to the blowing pipeline; or the outlet of the first gas processing device is first connected to the gas storage chamber, and the inlet of the second gas processing device Connect to the gas storage chamber, and connect the outlet of the second gas processing device to the blowing pipeline.

Compared with the prior art, the regenerative impact heat transfer device for industrial furnaces of the present invention has the following characteristics:

1. The flue gas passes through the heat exchange of the regenerator to make full use of heat energy. At the same time, the temperature of the flue gas heated by the regenerator is still suitable for spraying directly on the workpiece to be heated, directly heating the workpiece, and significantly improving the heating efficiency.

2. The flue gas that is forcibly accelerated by the fan is blown into the furnace at high speed from the air inlet nozzle, and is forced to convect. When it is directly sprayed on the workpiece to be heated at high speed to heat the workpiece, it also produces forced agitation, which significantly improves the convective heat transfer coefficient.

3. Blowing from the inlet nozzle to the furnace at high speed produces forced agitation, improves the temperature and gas uniformity in the furnace, and heats the workpiece more uniformly.

4. The present invention makes full use of the regenerator as the heat exchange medium, heats the flue gas through the regenerator, maximizes the use of the heat generated by combustion, and significantly improves the heating efficiency; at the same time, forced convection and directly sprays the high-temperature flue gas on the waiting area. On the heating workpiece, the convective heat transfer coefficient is significantly improved; it is verified by experiments that the heating efficiency of the present invention is increased by 20% or even higher on the basis of the original regenerative combustion, which is not an exaggeration to say that it is a major breakthrough.

5. By supplementing the heat of the hot flue gas, that is, adding a small amount of heat to the hot flue gas, a small amount of heat can be provided by fuel combustion or electric heating. Temperature adaptation to improve uniformity while increasing convection capacity.

Description of drawings

Fig. 1 is a schematic structural view of a regenerative impingement heat transfer device for an industrial furnace of the present invention;

Fig. 2 is the structural schematic diagram of the second embodiment of the regenerative impingement heat transfer device for industrial furnaces of the present invention;

Fig. 3 is a structural schematic diagram of the third embodiment of the regenerative impingement heat transfer device for industrial furnaces of the present invention.

detailed description

As shown in Figure 1, the regenerative impingement heat transfer device for industrial furnaces of the present invention includes a gas treatment device 1 that pressurizes the gas to increase the flow rate, and a gas extraction pipeline 2 through which the gas enters the gas treatment device 1 and a gas discharge gas treatment device. The blowing pipeline 3 of the device 1, the suction pipeline 2 and the blowing pipeline 3 are respectively arranged at the air inlet and the exhaust port of the gas processing device 1, and the gas processing device 1 is a fan (blower), etc., which pressurize the gas , to increase the flow rate of gas in the blowing pipeline 3.

On the air extraction pipeline 2, two air extraction branches are respectively set, namely the first air extraction branch 4 and the second air extraction branch 5; on the air blowing pipeline 3, two air blowing branches are respectively set, namely The first air blowing branch 6 and the second air blowing branch 7; the first air extraction branch 4 and the first air blowing branch 6 are respectively provided with control valves, which are all connected to the first heat storage body under controlled conditions. 8, the pipeline behind the first regenerator 8 is provided with a first opening 9, which is used as an outlet for air extraction or an inlet for air intake; the second air extraction branch 5 and the second air blowing branch 7 are respectively A control valve is provided, which communicates with the second regenerator 10 under controlled conditions, and a second opening 11 is provided on the pipeline behind the second regenerator 10 as an outlet for air extraction or an inlet for air intake. During operation, under the action of the control valve, the first opening 9 and the second opening 11 are used in turn as the discharge port for air extraction or the blowing port for air intake.

In order to increase the gas injection speed, nozzles 12 are arranged on the first opening 9 and the second opening 11, the cross-sectional area of the nozzles 12 is gradually reduced, forming a necking effect to increase the flow velocity, forming a high-speed nozzle, and the gas ejected from the nozzle 12 Higher speed, spraying directly onto the workpiece to be heated. The preferred configuration of the nozzle 12 is circular, conical with tapered cross-section. The gas ejected from the nozzle 12 usually reaches more than 80 m/s. The effect of low speed is not good, and the noise is too high if the speed is too high. The preferred solution is 150 m/s-200 m/s to form a high-speed flowing air flow.

On the pipeline between the first opening 9 and the first heat storage body 8, a first gas collection box 13 is arranged, and on the pipeline between the second opening 11 and the second heat storage body 10, a second gas collection box is arranged 14. The structure of the first gas collection box 13 and the second gas collection box 14 can be the same, the main function is to increase the cross-sectional area of the pipeline in front of the first opening 9 and the second opening 11, or the cross-sectional area in front of the nozzle 12 Area, the formation of static pressure, conducive to the formation of high-speed jet.

The controlled state of the present invention is to set control valves respectively on the first air extraction branch 4 and the second air extraction branch 5, the first air blowing branch 6 and the second air blowing branch 7, in order to control the first The pipelines of the first air extraction branch 4 and the second air extraction branch 5, the first air blowing branch 6 and the second air blowing branch 7 are switched on and off to form a circulation pipeline with one air intake and the other air exhaust; FIG. As shown in , on the first air extraction branch 4 and the second air extraction branch 5, the first air blowing branch 6 and the second air blowing branch 7, a manual control valve 16 and an automatic reversing valve 17 are respectively set , the manual control valve 16 and the automatic reversing valve 17 are in series structure, and the manual control valve 16 is used for manual manual operation control when needed; the automatic reversing valve 17 on two or four branch pipelines can be set in linkage, such as using a solenoid valve Or hydraulic valves, etc., act at the same time and switch on and off at the same time, so that the commutation is accurate and the circulation channel for the flue gas flow is formed.

On the pipeline between the first opening 9 and the first heat storage body 8, or on the first gas collecting box 13, a supplementary gas channel 18 is provided, and when necessary, the supplementary gas channel 18 is opened to supplement a small amount of fuel into the pipeline , adding a small amount of fuel to the hot flue gas, increasing the temperature of the hot flue gas to adapt to the furnace temperature, can improve the convection capacity of the medium and high temperature sections, and improve the uniformity. On the pipeline between the second opening 11 and the second heat storage body 10, or on the second gas collecting box 14, a supplementary gas channel 18 is provided, and the supplementary gas channel 18 is opened when necessary, and a small amount of fuel is added to the pipeline .

In addition, after a longer heating time, or after the furnace temperature is higher, the temperature of the regenerator itself is higher, resulting in a higher temperature of the gas entering the gas treatment device 1 from the extraction pipeline 2, which may affect the temperature of the gas treatment device 1. In normal use, the present invention sets the auxiliary air intake pipeline 20 on the air extraction pipeline 2, opens the auxiliary air intake pipeline 20 when needed, and replenishes cold air in the air extraction pipeline 2 to reduce the temperature of the gas in the air extraction pipeline 2, so as to Protective gas treatment device 1. Of course, the gas treatment device 1 also needs to be provided with a safety exhaust pipeline, which can be opened when necessary to discharge the gas in the gas treatment device 1 or the blowing pipeline 3 to the outside to relieve pressure.

As shown in the schematic diagram of the use state of the heating device of the present invention, the heating device of the present invention is arranged on the industrial furnace body 30, and the cavity in the middle of the industrial furnace body 30 forms a furnace 31, and the workpiece to be heated is placed in the furnace 31 to be heated. On the furnace 31, two openings are set, the first furnace port 32 and the second furnace port 33, the first furnace port 32 and the second furnace port 33 communicate with the furnace chamber 31 respectively, and the first port 9 and the second port 11 are provided respectively On the first furnace port 32 and the second furnace port 33, when one of them is used as an air inlet after sealing, the other is then used as an exhaust port, which takes turns in and out respectively, and is connected with the exhaust pipeline 2 and the gas treatment device 1 respectively. The gas blowing pipeline 3 is connected to form a circulation loop, forming an intake and exhaust circulation passage for flue gas in the furnace 31 .

In the regenerative impact heat transfer device for industrial furnaces of the present invention, when the combustion device of the industrial furnace body 30 is burning, the industrial furnace 31 and the workpiece to be heated in the furnace 31, the gas processing device 1 is turned on, and the control valve on the pipeline is adjusted. , the higher temperature flue gas in the furnace 31 is discharged from the second opening 11, passes through the second regenerator 10, and enters the exhaust pipeline 2 of the gas treatment device 1, and after being pressurized by the gas treatment device 1, it is discharged from the blower The high-speed gas discharged from the gas pipeline 3 enters the furnace 31 at a high speed from the first opening 9 through the first regenerator 8 in the blowing pipeline 3, forming a high-speed impact convective heat transfer, and the high-speed airflow is directly sprayed to the furnace 31 to be heated. On the workpiece, the convective heat transfer efficiency is improved; the control valve on the pipeline is adjusted, the gas flows in the opposite direction, and the flue gas with a higher temperature in the furnace 31 is discharged from the first opening 9 and the first regenerator 8, and enters the gas treatment device 1 The gas extraction pipeline 2, after being pressurized by the gas treatment device 1, the high-speed gas discharged from the gas blowing pipeline 3 enters the furnace 31 at a high speed through the second regenerator 10 from the second opening 11 in the gas blowing pipeline 3, forming High-speed impact convective heat transfer, the high-speed airflow is directly sprayed onto the workpiece to be heated in the furnace 31 to improve the convective heat transfer efficiency. During the combustion and heating process of the industrial furnace body 1, the pipelines where the first heat accumulator 8 and the second heat accumulator 10 are located are respectively used as air intake and exhaust pipelines in turn, and the first opening 9 and the second opening 11 are respectively used as The flue gas of the furnace 31 enters and exhausts, and the high-temperature flue gas exchanges heat through the regenerator on the pipeline. ℃), the other port heats the gas pressurized by the gas treatment device 1 after passing through the regenerator on the pipeline, and the flue gas with increased temperature enters the furnace 31 at a high speed through this port, forming a high-speed impact Type convective heat transfer; under the control of the control valve, the pipelines where the first regenerator 8 and the second regenerator 10 are located are respectively used as the intake and exhaust pipelines in turn, and the intake and exhaust are taken in turn to form A circulation channel for flue gas flow in the furnace 31 .

In the present invention, through the pipeline where the first heat storage body 8 and the second heat storage body 10 are located, the first heat storage body 8 and the second heat storage body 10 act as a medium, and the two heat storage bodies absorb and release heat in turn, One absorbs the heat of the high-temperature flue gas discharged from the furnace 31 and stores it on the regenerator, so that the temperature of the gas is lowered and enters the gas treatment device 1 for pressure treatment; the flue gas after pressure treatment from the gas treatment device 1 flows through the second When a regenerator is formed (the regenerator is in a high temperature state at this time), the flue gas is reheated to form a high-temperature, high-velocity (high-pressure) gas that is sprayed into the furnace 31 and directly acts on the workpiece to be heated, significantly improving the convection flow. Heat coefficient; especially in the process of rising from low temperature to high temperature, a heat storage type impact heat transfer is formed, which improves the convective heat transfer coefficient many times and significantly improves the heating efficiency; it has been verified by experiments that the heating efficiency of the present invention is higher than that of traditional heat storage Based on the combustion furnace, the heating efficiency can be increased by at least 20%, or even higher.

The first regenerator 8 and the second regenerator 10 of the present invention are arranged in pairs, and there are passages and heat exchange media for the passage of gas in it, and the regenerator of the regenerative combustion furnace in the prior art can be used as The prior art will not be further described here. According to actual needs, if there are multiple industrial furnaces, or more than one air extraction port and air blowing port are to be set on the same industrial furnace, multiple first air extraction branches can be set on the air extraction line 2 and the air blowing line 3 , the second air extraction branch, the first air blowing branch and the second air blowing branch, use this device to supply flue gas to multiple industrial furnaces at the same time, or pass more than one air extraction port and air blowing port to the same industrial furnace Multi-channel air extraction and air blowing form a circulation path for flue gas, which can be recycled separately.

In the structure of the second embodiment of the present invention shown in Fig. 2, the same parts as Fig. 1 will not be introduced again, and the difference is as follows: there are two gas treatment devices 1, or more than two, and the figure is a series structure, The first gas processing device 101 and the second gas processing device 102 are connected in series, the gas extraction pipeline 2 is connected to the inlet of the first gas processing device 101, and the pipeline of the outlet of the first gas processing device 101 is directly connected to the first gas processing device 101. The inlet of the two gas treatment devices 102, the outlet of the second gas treatment device 102 is connected to the blowing pipeline 3; or the outlet of the first gas treatment device 101 is first connected to the gas storage chamber 103, and the gas is passed into the gas storage chamber Cache in the body 103; the inlet of the second gas processing device 102 is connected to the gas storage chamber 103, and the outlet of the second gas processing device 102 is connected to the blowing pipeline 3; the difference is that the supplementary gas channel 18 can also be directly connected to In the furnace 31, a certain amount of gas is directly added to the furnace 31 as required.

As shown in Figure 3, the structure of the third embodiment of the present invention, the same part as that of Figure 1 will not be introduced, and the difference is as follows: a supplementary heat burner 21 is provided, and the supplementary heat burner 21 is connected with the first opening 9 or The second openings 11 communicate with each other, and the supplementary heat burner 21 is provided with a fuel feed pipe 22 and a combustion-supporting gas inlet pipe 23. The pipe 23 leads into the reheating burner 21, and then flows into the furnace from the first opening 9 or the second opening 11 respectively.

On the furnace 31, a gas release pipeline with a control valve can also be set, and the pressure relief can be opened when necessary to ensure that the pressure of the furnace gas in the furnace is normal and play a safety role.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the technical solutions. Although the applicant has described the present invention in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that those who understand the present invention Any modification or equivalent replacement of the technical solution of the invention without departing from the spirit and scope of the technical solution shall be covered by the scope of the claims of the present invention.

Claims (10)

1. The regenerative impingement heat transfer device for industrial furnaces is characterized in that it includes a gas processing device (1) for pressurizing the gas, and the gas extraction pipeline (2) and the gas blowing pipeline (3) are respectively arranged in the gas processing device (1) suction port and gas outlet; on the suction pipeline (2), respectively set the first suction branch (4) and the second suction branch (5), on the blowing pipeline (3), The first blowing branch (6) and the second blowing branch (7) are respectively set; the first suction branch (4) and the first blowing branch (6) are respectively connected with the A heat accumulator (8) is connected, and a first opening (9) is set on the pipeline behind the first heat accumulator (8), which is used as the exhaust outlet of the air extraction or the inlet of the air intake; the second air extraction branch ( 5) and the second blowing branch (7) are respectively in communication with the second heat storage body (10) under control, and the second opening (11) is set on the pipeline behind the second heat storage body (10) , as the exhaust port of the suction or the blowing port of the air intake. 2. The regenerative impingement heat transfer device for industrial furnaces according to claim 1, characterized in that: Nozzles (12) are provided on the first opening (9) and the second opening (11), and the transverse direction of the nozzle (12) The section is gradually reduced. 3. The regenerative impingement heat transfer device for industrial furnaces according to claim 1, characterized in that: the controlled state is in the first air extraction branch (4), the second air extraction branch (5 ) and the first blowing branch (6) and the second blowing branch (7) are respectively provided with control valves to switch each branch to form one way to blow gas into the furnace (31) and the other way to blow gas into the furnace (31). A circulation pipe for extracting gas from the furnace (31). 4. The regenerative impingement heat transfer device for industrial furnaces according to claim 3, characterized in that: each branch pipeline is provided with an automatic reversing valve (17) and/or a manual control valve (16). 5. The regenerative impingement heat transfer device for industrial furnaces according to claim 4, characterized in that: the automatic reversing valves (17) on two or four branch roads are set in linkage to generate actions at the same time and control two or four branches at the same time. On-off branch. 6. The regenerative impingement heat transfer device for industrial furnaces according to any one of claims 1-5, characterized in that: on the pipeline between the first opening (9) and the first regenerator (8), a The first gas collection box (13), the second gas collection box (14) is arranged on the pipeline between the second opening (11) and the second heat storage body (10). 7. The regenerative impingement heat transfer device for industrial furnaces according to claim 6, characterized in that: on the pipeline between the first opening (9) and the first regenerator (8), or the first gas collector Set the supplementary gas channel (18) on the tank (13); set the supplementary gas channel (18) on the pipeline between the second opening (11) and the second heat storage body (10), or on the second gas collecting box (14). channel (18). 8. The regenerative impingement heat transfer device for industrial furnaces according to any one of claims 1-5, characterized in that: an auxiliary air intake pipe (20) is provided on the air extraction pipe (2). 9. The regenerative impingement heat transfer device for industrial furnaces according to claim 6, characterized in that: a supplementary heat burner (21) is also provided, and the supplementary heat burner (21) is connected with the first opening (9) or the first opening (9) The two openings (11) are connected respectively, and the fuel feeding pipe (22) and the combustion-supporting gas inlet pipe (23) are set on the supplementary heating burner (21), and the required fuel and combustion-supporting gas are respectively fed from the fuel under control. The feed pipe (22) and the combustion-supporting gas inlet pipe (23) pass into the supplementary heat burner (21), and then pass into the furnace (31). 10. The regenerative impingement heat transfer device for industrial furnaces according to any one of claims 1-5, characterized in that: there are two gas processing devices (1), the first gas processing device (101) and the second The two gas treatment devices (102) are connected in series, the pumping pipeline (2) is connected to the inlet of the first gas treatment device (101), and the pipeline at the outlet of the first gas treatment device (101) is directly connected to the second The inlet of the first gas processing device (102), the outlet of the second gas processing device (102) is connected to the blowing pipeline (3); or the outlet of the first gas processing device (101) is first connected to the gas storage chamber (103 ), the inlet of the second gas processing device (102) is connected to the gas storage chamber (103), and the outlet of the second gas processing device (102) is connected to the blowing pipeline (3).