CN205192294U - Modified radiant tube heat transfer device - Google Patents

Abstract

The utility model belongs to the field of heat exchanging devices, and relates to an improved radiant tube heat exchanging device, which is especially suitable for industries using petrochemical fuels for heat treatment. The radiant tube heat exchange device includes a first-stage heat exchange tube and a second-stage heat exchange tube; the heat exchange tubes at each level are arranged in sequence from the inside to the outside with an inner tube, a finned tube and an outer tube, and the two outer tubes are connected to each other. The opening ends of the two outer pipes are the flue gas inlet (1) and the flue gas outlet (6) respectively; the air inlet (10) and the air outlet (5) entering the inner pipe are respectively opened near the connecting ends of the two outer pipes, completing The air to be heat-exchanged flows back and forth multiple times inside the heat-exchange tube. The utility model adopts double-stage or multi-pole heat exchange, which can improve the heat exchange efficiency of the traditional radiant tube heat exchanger, reduce energy consumption and save space and cost.

Description

An Improved Radiant Tube Heat Exchanger

technical field

The utility model belongs to the field of heat exchanging devices, and relates to an improved radiant tube heat exchanging device, which is especially suitable for industries using petrochemical fuels for heat treatment, and realizes waste heat recovery of flue gas.

Background technique

At present, it is more common to use gas radiant tubes for heat treatment in the market. For the consideration of energy saving and consumption reduction, most of them use the flue gas generated after their own combustion to preheat the combustion air through radiant tube heat exchangers. The traditional radiant tube heat exchanger is a single-stage heat exchange. For example, Chinese invention patent application No. 201210197143.8 provides an 'air swirl jet radiant tube heat exchanger'. This type of single-stage heat exchange structure has a small heat exchange area and limited heat exchange efficiency. Generally, after the flue gas at 1050 °C passes through the radiant tube heat exchanger, the air temperature after preheating is at most about 350 °C, and the flue gas temperature after heat exchange is Mostly around 680°C. With the development of the market, traditional radiant tube heat exchangers have gradually failed to meet energy-saving requirements. Insufficient use of flue gas waste heat will result in high energy consumption and high costs. Improving heat exchange efficiency is the research and development of new radiant tube heat exchangers. focus.

Contents of the invention

The purpose of the utility model is to provide an improved radiant tube heat exchange device, which adopts double-stage or multi-pole heat exchange, can improve the heat exchange efficiency of the traditional radiant tube heat exchanger, and save space and cost at the same time.

In order to achieve the above object, the utility model provides the following technical solutions:

The utility model provides an improved radiant tube heat exchange device. The radiant tube heat exchange device includes a first-stage heat exchange tube and a second-stage heat exchange tube which complete two-stage heat exchange;

The heat exchange tubes at all levels are arranged in sequence from the inside to the outside with inner tubes, finned tubes and outer tubes. The two outer tubes are connected to each other, and the open ends of the two outer tubes are the flue gas inlet 1 and the flue gas outlet 6 respectively; An air inlet 10 and an air outlet 5 entering the inner tube are respectively opened near the connecting end of the tube, so as to complete the multiple turn-back flow of the air to be exchanged inside the heat exchange tube.

In this device, the flow direction of the flue gas is: the first flue gas channel a → the second flue gas channel b; the flow direction of the air is: the first air channel c → the second air channel d → the third air channel e → Fourth air channel f.

The first-stage heat exchange tube includes a flue gas inlet 1, a first outer tube 2, a first finned tube 3, a first inner tube 4 and an air outlet 5; the open end of the first outer tube 2 is provided with a flue gas inlet 1. One end of the first finned tube 3 is a sealed end, and the other end is a connecting end; one end of the first inner tube 4 is an open end, and the other end is provided with an air outlet 5, which passes through the first finned tube in turn 3. The first outer tube 2;

The second-stage heat exchange tube includes a flue gas outlet 6, a second outer tube 7, a second finned tube 8, a second inner tube 9 and an air inlet 10; one end of the second outer tube 7 is provided with a flue gas outlet 6 , the other end is the connection end and is airtightly connected with the connection end of the first outer tube 2; Connection; one end of the second inner tube 9 is an open end, and the other end is provided with an air inlet 10, and the air inlet 10 passes through the second finned tube 8 and the second outer tube 7 in turn.

The flue gas inlet 1 is connected to the radiant tube K; the flue gas outlet 6 is connected to the exhaust pipe L; the air inlet 10 is connected to the air pipe M; the air outlet 5 is connected to the burner pipe N.

The included angle α between the first-stage heat exchange tubes and the second-stage heat exchange tubes is 45-180 degrees.

Preferably, the first-stage heat exchange tubes are vertically connected to the second-stage heat exchange tubes.

The flue gas inlet 1 , flue gas outlet 6 , air inlet 10 and air outlet 5 can adopt different orientations and interface forms according to different external devices.

The air inlet 10 and the air outlet 5 can be respectively arranged on the side or end of different outer tubes or the same outer tube.

The first flue gas channel a is formed between the first finned tube 3 and the radiant tube K and the first outer tube 2; the second flue gas channel b is formed between the second finned tube 8 and the second outer tube 7; The air passage in the second inner tube 9 is the first air channel c; the second air channel d is formed between the second finned tube 8 and the second inner tube 9; the first finned tube 3 and the first inner tube 4 The third air channel e is formed between them; the air flow channel in the first inner tube 4 is the fourth air channel f; wherein, the first smoke channel a communicates with the second smoke channel b; the first air channel c communicates with the second air channel Channel d communicates, the second air channel d communicates with the third air channel e, the third air channel e communicates with the fourth air channel f; the air channel and the smoke channel are not communicated with each other.

The device further includes a third-stage heat exchange tube or more heat exchange tubes.

Compared with the prior art, the utility model has the beneficial effects of:

The utility model adopts multi-stage heat exchange to increase the heat exchange area, improve the heat exchange efficiency of the radiant tube heat exchanger, have flexible design, strong adaptability, save space, reduce energy consumption, reduce cost, and reduce the impact of flue gas on the environment. Improve the competitiveness of products. After the flue gas at 1050°C passes through the heat exchange of the utility model, the air temperature can reach about 580°C after preheating, and the flue gas temperature can reach about 350°C after heat exchange.

Description of drawings

Fig. 1 is the front view of the utility model heat exchange device;

Fig. 2 is the left view of Fig. 1;

Fig. 3 is the A-A direction sectional view of Fig. 2;

Fig. 4 is the B-B direction sectional view of Fig. 1;

Fig. 5 is the C-C direction sectional view of Fig. 1;

Fig. 6 is a schematic diagram of air inlet and outlet adjustment in Embodiment 2 of the present utility model;

Fig. 7 is a schematic diagram of adjusting the import and export of flue gas in Embodiment 3 of the present utility model;

Fig. 8 is a schematic structural view of Embodiment 4 of the present invention, in which the first-stage heat exchange tubes and the second-stage heat exchange tubes are connected in a straight line.

The reference signs therein are:

1 flue gas inlet 2 first outer pipe

3 first finned tube 4 first inner tube

5 air outlet 6 flue gas outlet

7 second outer tube 8 second finned tube

9 second inner tube 10 air inlet

a The first flue gas channel b The second flue gas channel

c first air channel d second air channel

e Third air channel f Fourth air channel

K radiant tube L smoke exhaust pipe

M air duct N burner duct

α Angle between the first stage heat exchange tube and the second stage heat exchange tube

Note:

The first flue gas channel a is the air flow channel between the first finned tube, the radiant tube and the first outer tube;

The second flue gas channel b is an air flow channel between the second finned tube and the second outer tube;

The first air channel c is the air flow channel in the second inner tube;

The second air channel d is an air flow channel between the second finned tube and the second inner tube;

The third air channel e is an air flow channel between the first finned tube and the first inner tube;

The fourth air channel f is an air flow channel in the first inner tube.

detailed description

The utility model provides an improved radiant tube heat exchange device, as shown in Figure 1-3, the radiant tube heat exchange device includes a first-stage heat exchange tube and a second-stage heat exchange tube;

As shown in Figure 4, the first-stage heat exchange tube includes a flue gas inlet 1, a first outer tube 2, a first finned tube 3, a first inner tube 4 and an air outlet 5;

One end of the first outer tube 2 is provided with a flue gas inlet 1, and the other end is a connecting end. The first outer tube 2 is set on the outside of the first finned tube 3; one end of the first finned tube 3 is a sealing end, and the other end As the connection end, the first finned tube 3 is set on the outside of the first inner tube 4; one end of the first inner tube 4 is an open end, and the other end is provided with an air outlet 5, and passes through the first finned tube 3, first outer tube 2;

As shown in Figure 5, the second-stage heat exchange tube includes a flue gas outlet 6, a second outer tube 7, a second finned tube 8, a second inner tube 9 and an air inlet 10;

One end of the second outer tube 7 is provided with a flue gas outlet 6, the other end is a connection end and is airtightly connected with the connection end of the first outer tube 2, and the second outer tube 7 is set on the outside of the second finned tube 8; One end of the two finned tubes 8 is a sealing end, the other end is a connecting end and is airtightly connected with the connecting end of the first finned tube 3, and the second finned tube 8 is sleeved on the outside of the second inner tube 9; One end of the tube 9 is an open end, and the other end is provided with an air inlet 10, and passes through the second finned tube 8 and the second outer tube 7 in sequence.

The flue gas inlet 1 is connected to the radiant tube K; the flue gas outlet 6 is connected to the exhaust pipe L; the air inlet 10 is connected to the air pipe M; the air outlet 5 is connected to the burner pipe N.

The included angle α between the first-stage heat exchange tube and the second-stage heat exchange tube is 45-180 degrees.

Preferably, the first-stage heat exchange tubes are vertically connected to the second-stage heat exchange tubes.

The flue gas inlet 1, the flue gas outlet 6, the air inlet 10 and the air outlet 5 can adopt different orientations and interface forms according to different external devices.

After the flue gas at 1050°C passes through the radiant tube heat exchanger for heat exchange, the flue gas temperature is ≤350°C, and the air temperature after preheating is ≥580°C.

The first flue gas channel a is formed between the first finned tube 3 and the radiant tube K and the first outer tube 2; the second flue gas channel b is formed between the second finned tube 8 and the second outer tube 7; The airflow channel in the inner tube 9 is the first air channel c; the second air channel d is formed between the second finned tube 8 and the second inner tube 9; the second air channel d is formed between the first finned tube 3 and the first inner tube 4 The third air channel e; the air flow channel in the first inner tube 4 is the fourth air channel f; wherein, the first smoke channel a communicates with the second smoke channel b; the first air channel c communicates with the second air channel d In communication, the second air passage d communicates with the third air passage e, and the third air passage e communicates with the fourth air passage f; the air passage and the smoke passage do not communicate with each other. The flue gas and air entering the radiant tube heat exchanger do not interfere with each other and go their own way.

The device further includes third-stage heat exchange tubes or multi-stage heat exchange tubes.

The working process of the present utility model is:

The cold air coming from the air pipe M enters the second inner pipe 9 through the air inlet 10, and enters the second air passage d after being reversed through the first air passage c. The heat exchange completes the first-stage heat exchange; the air enters the third air passage e after reversing, enters the first inner tube 4 after reversing again, and flows out from the air outlet 5 after passing through the fourth air passage f. During the circulation process, the air and flue gas The heat exchange is performed through the first finned tube 3 to complete the secondary heat exchange, and after the final heat exchange, the hot air passes through the burner pipe N externally connected to the air outlet 5 to participate in ignition and combustion.

The high-temperature flue gas from the radiant tube K enters the first outer pipe 2 through the flue gas inlet 1, and flows through the first flue gas channel a. During the circulation process, the flue gas and air exchange heat through the first finned tube 3 to complete the first stage. Heat exchange; the flue gas enters the second flue gas channel b after turning around. During the circulation process, the flue gas and air exchange heat through the second finned tube 8 to complete the secondary heat exchange. After the final heat exchange, the flue gas passes through the flue gas outlet 6 to connect Into the exhaust pipe L.

Below in conjunction with embodiment the utility model is further described.

Example 1

Referring to Figures 1 to 5, the new radiant tube heat exchange device provided in this embodiment, the first-stage heat exchange tube and the second-stage heat exchange tube are basically vertically connected, the flue gas inlet 1 is connected to the first outer pipe 2, and the flue gas outlet 6 is connected to the second outer tube 6, the air inlet 10 and the air outlet 5 are respectively located near the connecting ends of the two outer tubes, the air inlet 10 is opened on the outer side of the second outer tube, and the air outlet 5 is opened on the outer side of the first outer tube.

Example 2

Referring to Fig. 6, embodiment 2 adjusts the arrangement of the air inlet 10 and the air outlet 5: one of the inlet and the outlet is located on the side of the outer tube, and the other is located at the end of the outer tube.

Example 3

Referring to Fig. 7, in embodiment 3, a connecting pipe is added at the outlet end of the flue gas outlet 6, which can match devices of different orientations and styles.

Example 4

Referring to Fig. 8, in Embodiment 4, the connection angle of the first-stage heat exchange tubes and the second-stage heat exchange tubes can be adjusted as required, here they are connected in a straight line.

Claims (10)

1. the radiant tube heat-exchanger rig improved, is characterized in that: this radiant tube heat-exchanger rig has comprised first order heat exchanger tube and the second level heat exchanger tube of two-stage heat exchange;

Heat exchanger tube at different levels is from inside to outside furnished with interior pipe, finned tube and outer tube successively, and two outer tubes are connected to each other, and the openend of two outer tubes is respectively gas approach (1) and exhanst gas outlet (6); Have the air intlet (10) and air outlet slit (5) that enter interior pipe near the link of two outer tubes, complete repeatedly the turn back flowing of hot-air to be changed in heat exchanger tube inside.

2. the radiant tube heat-exchanger rig of improvement according to claim 1, it is characterized in that: in this device, the flow direction of flue gas is followed successively by: the first exhaust gases passes (a) → the second exhaust gases passes (b); The flow direction of air is followed successively by: the first air duct (c) → the second air duct (d) → the 3rd air duct (e) → the 4th air duct (f).

3. the radiant tube heat-exchanger rig of improvement according to claim 1, is characterized in that: described first order heat exchanger tube comprises pipe (4) and air outlet slit (5) in gas approach (1), the first outer tube (2), the first finned tube (3), first; The openend of the first outer tube (2) is provided with gas approach (1); One end of first finned tube (3) is sealed end, and the other end is link; In first, one end of pipe (4) is openend, and the other end is provided with air outlet slit (5), and air outlet slit (5) is successively through the first finned tube (3), the first outer tube (2);

Described second level heat exchanger tube comprises pipe (9) and air intlet (10) in exhanst gas outlet (6), the second outer tube (7), the second finned tube (8), second; One end of second outer tube (7) is provided with exhanst gas outlet (6), and the other end is link and is tightly connected with the link of the first outer tube (2); One end of second finned tube (8) is sealed end, and the other end is link and is tightly connected with the link of the first finned tube (3); In second, one end of pipe (9) is openend, and the other end is provided with air intlet (10), and air intlet (10) is successively through the second finned tube (8), the second outer tube (7).

4. the radiant tube heat-exchanger rig of improvement according to claim 1, is characterized in that: described gas approach (1) connects radiant tube (K); Exhanst gas outlet (6) connects smoke discharging pipe (L); Air intlet (10) connects air duct (M); Air outlet slit (5) connects burner tubes (N).

5. the radiant tube heat-exchanger rig of improvement according to claim 1, is characterized in that: the angle α between described first order heat exchanger tube and second level heat exchanger tube is 45 ~ 180 degree.

6. the radiant tube heat-exchanger rig of improvement according to claim 1, is characterized in that: described first order heat exchanger tube is connected with second level heat exchanger tube is vertical.

7. the radiant tube heat-exchanger rig of improvement according to claim 1, is characterized in that: described gas approach (1), exhanst gas outlet (6), air intlet (10) and air outlet slit (5) all can take different orientation and interface shape according to the difference of external equipment.

8. the radiant tube heat-exchanger rig of improvement according to claim 1, is characterized in that: air intlet (10) and air outlet slit (5) can be separately positioned on side or the end of different outer tube or same outer tube.

9. the radiant tube heat-exchanger rig of improvement according to claim 3, is characterized in that: the first finned tube (3) and radiant tube (K), the first outer tube form the first exhaust gases passes (a) between (2); The second exhaust gases passes (b) is formed between second finned tube (8) and the second outer tube (7); Gas channel in second in pipe (9) is the first air duct (c); Manage between (9) in second finned tube (8) and second and form the second air duct (d); Manage between (4) in first finned tube (3) and first and form the 3rd air duct (e); Gas channel in first in pipe (4) is the 4th air duct (f); Wherein, the first exhaust gases passes (a) is communicated with the second exhaust gases passes (b); First air duct (c) is communicated with the second air duct (d), second air duct (d) is communicated with the 3rd air duct (e), and the 3rd air duct (e) is communicated with the 4th air duct (f); Not connected between air duct and exhaust gases passes.

10. the radiant tube heat-exchanger rig of improvement according to claim 1, is characterized in that: this device comprises third level heat exchanger tube or more level heat exchanger tube further.