1. A heat exchange unit, characterized in that: the method comprises the following steps:

-a tank (11): the box body (11) is provided with a smoke inlet (111) and a smoke outlet (112), the two ends of the box body are respectively provided with an air inlet (114) and an air outlet (115), and the bottom of the box body is provided with a liquid outlet (113);

-heat exchange tubes (14): the heat exchange tubes (14) are arranged in the box body (11) in parallel and communicated with the air inlet (114) and the air outlet (115), the cross sections of the heat exchange tubes (14) are rectangular or long-runway type, and long central shafts of the heat exchange tubes are vertical to the bottom surface of the box body (11);

-end plate (13): the heat exchange tube is arranged at the air inlet (114) and the air outlet (115), the end plate (13) is provided with a plurality of through holes corresponding to the tube openings of the heat exchange tube (14), and the tube openings at two ends of the heat exchange tube (14) are fixed on the through holes of the end plate (13);

-a spraying device (5): the spraying device (5) is arranged at the top of the inner cavity of the box body (11);

-a refrigerant medium flows in the heat exchange tubes (14), and a heat medium flows in the space inside the box (11) and outside the heat exchange tubes (14), and the two exchange heat through the walls of the heat exchange tubes (14).

2. The heat exchange unit of claim 1, wherein: the outer side surface of the end plate (13) is retracted from the end surfaces of the two sides of the box body (11).

3. The heat exchange unit of claim 1, wherein: the periphery of the end faces of two sides of the box body (11) is extended with flange plates (17), and the box body (11) is provided with a liquid level meter (16).

4. A flue gas waste heat recovery exchanger assembled by the heat exchange units of claim 1, wherein:

the heat exchanger is provided with at least one section of heat exchange unit (1), an upper air outlet (115) and a lower air inlet (114) of two adjacent heat exchange units (1) are communicated, an upper smoke outlet (112) and a lower smoke inlet (111) are communicated through a connecting pipe (5), and a liquid outlet (113) of each section of heat exchange unit (1) is communicated to a water tank (6);

an air inlet (114) of the foremost heat exchange unit (1) is communicated with the fan (2) through the air supply hood (3), and an air outlet (115) of the rearmost heat exchange unit (1) is connected with the air supply hood (4);

the heat medium enters the inner cavity of the box body (11) from the smoke inlet (111) of the rearmost heat exchange unit (1), flows along the connecting pipe (5), enters the next heat exchange unit (1) and is discharged from the smoke outlet (112) of the foremost heat exchange unit (1); refrigerant medium is sent into the air inlet (114) of the foremost heat exchange unit (1) by the fan (2), flows to the rearmost heat exchange unit (1) along the heat exchange pipe (14) and is discharged from the air outlet (115) of the rearmost heat exchange unit.

5. The flue gas waste heat recovery exchanger according to claim 4, wherein: the connecting pipe (5) is in a semi-arc shape.

6. A flue gas waste heat recovery process using the exchanger of claim 4, characterized by comprising the steps of:

-step I: the refrigerant flows in the heat exchange tube (14) and exchanges heat with the heating medium outside the tube through the tube wall;

-step II: after working for a period of time, spraying and soaking in one section of the heat exchange unit (1) to clean dirt outside the pipe wall on line; discharging the cleaning liquid through a liquid discharge port (113) after cleaning;

-step III: and continuously carrying out online cleaning in the next section of heat exchange unit (1) as in the step II.

7. The flue gas waste heat recovery process according to claim 6, characterized in that: the liquid level of the cleaning liquid reaches 1/2-2/3 of the height of the box body.

8. The flue gas waste heat recovery process according to claim 6, characterized in that: the spraying takes water from the water tank (6), and the water is recycled.

Background

The textile printing and dyeing industry needs to consume a large amount of energy in the production process, enterprises cost more in the aspect of energy consumption every year, and the enterprises mainly adopt energy sources such as electricity, fuel oil, fuel gas, steam and the like for the technical processes such as desizing, boiling, rinsing, pad dyeing, high-temperature and high-pressure overflow dyeing, drying and shaping and the like, particularly, equipment can discharge a large amount of high-temperature harmful smoke outwards in the drying and shaping process, so that the environment is polluted, the smoke discharge temperature reaches 190-300 ℃, and the heat energy waste is large, so that the heat energy recycling equipment for the waste smoke is required by the textile printing and dyeing industry in energy saving and consumption reduction.

The existing flue gas waste heat recovery exchanger mostly adopts a fin type heat exchanger or a tube plate type heat exchanger, the fin type heat exchanger achieves the purpose of strengthening heat transfer by additionally arranging fins on heat exchange tubes, the dense arrangement structure of the fins is easy to deposit dust and is not easy to clean, the tube plate type heat exchanger is formed by welding or expanding a plurality of heat exchange tubes on an end plate welded on a shell, baffle plates are arranged on the heat exchange tubes to achieve the purpose of strengthening heat transfer, the heat exchange tubes are usually arranged in a honeycomb manner, and flue gas flows up and down in the shell, so that the problem of difficulty in cleaning exists, the heat exchange effect can be influenced after the heat exchanger is operated for a long time, and the heat recovery.

Disclosure of Invention

Aiming at the defects that the existing flue gas heat recovery exchangers are easy to accumulate dirt and difficult to clean, the invention provides the flue gas waste heat recovery exchanger which has simple and reasonable structure and convenient operation and installation, can simultaneously complete heat exchange and cleaning work, prevents blockage from influencing the heat exchange effect, and has economic and social benefits.

In order to achieve the technical purpose, the invention provides the following technical scheme and has the following beneficial effects:

a heat exchange unit comprising:

-a tank: the box body is provided with a smoke inlet and a smoke outlet, the two ends of the box body are respectively provided with an air inlet and an air outlet, and the bottom of the box body is provided with a liquid outlet;

-heat exchange tubes: the heat exchange tubes are arranged in the box body in parallel and communicated with the air inlet and the air outlet, the cross sections of the heat exchange tubes are rectangular or long-runway type, and long central shafts of the heat exchange tubes are vertical to the bottom surface of the box body;

-end plates: the heat exchange tube is arranged at the air inlet and the air outlet, a plurality of through holes corresponding to the tube orifices of the heat exchange tube are formed in the end plate, and the tube orifices at two ends of the heat exchange tube are fixed on the through holes of the end plate;

-a spray device: the spraying device is arranged at the top of the inner cavity of the box body;

the refrigerant medium flows in the heat exchange tube, the heat medium flows in the space inside the box body and outside the heat exchange tube, and the refrigerant medium and the heat medium exchange heat through the wall of the heat exchange tube.

The rectangular tubular heat exchanger is provided with the heat exchange units which are independent units, can flexibly adapt to the working condition requirements of different smoke discharge amounts by increasing or reducing the number of the heat exchange units, and is convenient to install and transport. Aiming at the problem that harmful impurities are usually contained in the flue gas, and the blockage between heat exchange tubes can be formed when the flue gas waste heat recovery exchanger is used for a long time, the spraying device is added in the box body, so that the online cleaning can be carried out during production, the cross section of each heat exchange tube is rectangular or long-runway and is vertically arranged, and compared with the existing tube-plate heat exchanger in which the heat exchange tubes are arranged in a honeycomb manner, the distance between the heat tubes is larger, so that the thorough washing and cleaning are facilitated.

As a further improvement of the above technical solution:

the outer side surface of the end plate is retracted from the end surfaces of two sides of the box body.

The lateral surface of end plate with can avoid the end plate protrusion to influence the erection joint of heat transfer unit, and need not during the installation with the heat exchange tube of last heat transfer unit and next heat transfer unit strict butt joint, only need at both ends with two box sealing connection can to sealed test, avoid leaking out to leak and influence the heat transfer effect, the installation is more simple and convenient.

The periphery of the end faces of the two sides of the box body is extended with flange plates, and the box body is provided with a liquid level meter.

When a plurality of heat exchange units are installed and connected, only the flange plates of the adjacent heat exchange units are needed to be connected, and the operation is simple; the liquid level meter can be used for monitoring the liquid level in the box body, and the ventilation effect is prevented from being influenced by too high water level.

A flue gas waste heat recovery exchanger assembled by the heat exchange unit of claim 1,

the heat exchanger has at least one section of heat exchange unit, the upper air outlet and the lower air inlet of two adjacent heat exchange units are communicated, the upper smoke outlet and the lower smoke inlet are communicated through a connecting pipe, and the liquid outlet of each section of heat exchange unit is communicated to the water tank;

an air inlet of the foremost heat exchange unit is communicated with the fan through the air supply cover, and an air outlet of the rearmost heat exchange unit is connected with the air supply cover;

the heat medium enters the inner cavity of the box body from the smoke inlet of the rearmost heat exchange unit, flows into the next heat exchange unit along the connecting pipe, and is discharged from the smoke outlet of the foremost heat exchange unit; the refrigerant medium is sent into the air inlet of the foremost heat exchange unit by the fan, flows to the rearmost heat exchange unit along the heat exchange pipe and is discharged from the air outlet of the rearmost heat exchange unit.

As a further improvement of the above technical solution:

the connecting pipe is in a semi-arc shape.

In order to realize good heat exchange effect, the length of the flow track of the flue gas needs to be increased, the invention increases the number of the heat exchange units, and the connecting pipe is arranged between the upper smoke exhaust port and the lower smoke inlet port to force the flue gas to flow according to certain guide, thereby ensuring that the heat exchange is more sufficient, improving the heat exchange effect, and simultaneously, the flue gas flows up and down on the water surface in the box body, and can stir the water surface to further wash and soak the dirt which peels off the outer wall of the box body and the heat exchange pipe.

A flue gas waste heat recovery process using the exchanger of claim 4, comprising the steps of:

-step I: the refrigerant flows in the heat exchange tube and exchanges heat with the heating medium outside the tube through the tube wall;

-step II: after working for a period of time, spraying and soaking in one section of heat exchange unit, and cleaning dirt outside the pipe wall on line; discharging the cleaning solution through a liquid outlet after cleaning;

-step III: and continuously carrying out online cleaning in the next section of heat exchange unit as in step II.

As a further improvement of the above technical solution:

the liquid level of the cleaning liquid reaches 1/2-2/3 of the height of the box body.

The spraying takes water from the water tank, and the water is recycled.

The high-temperature harmful flue gas is discharged from the upper-stage equipment and enters the flue gas waste heat recovery exchanger, the flue gas flows in the box body outside the heat exchange pipe and transfers heat energy to the heat exchange pipe, cold air is conveyed in the heat exchange pipe, the heat exchange pipe conducts the heat energy to the cold air to realize heat exchange, and finally hot air is output from the air outlet cover to finish heat exchange and is conveyed to the lower-stage equipment.

The flue gas waste heat recovery exchanger is full-automatic cleaning, a small amount of water or cleaning solution filled in the box body can soak and clean stubborn dirt, because each heat exchange unit is independent, the functions of heat exchange, cleaning and liquid drainage can be realized simultaneously, after flue gas enters the next unit from the previous heat exchange unit, clean water or cleaning solution is pumped out from the water tank by the spray pipe of the previous heat exchange unit to spray and wash the heat exchange pipe, waste liquid is drained into the water tank from a liquid drainage port after cleaning is finished, the rest heat exchange units still continue to carry out heat exchange, the previous heat exchange unit can immediately put into heat exchange work after being cleaned for 15-20 minutes, and full-efficiency work is carried out.

Drawings

Fig. 1 is a schematic structural diagram of a flue gas waste heat recovery exchanger according to the present invention.

Fig. 2 is a schematic structural diagram of the heat exchange unit of the present invention.

Fig. 3 is an enlarged view of a portion a in fig. 2.

FIG. 4 is a top view of a heat exchange unit.

Fig. 5 is a cross-sectional view B-B of fig. 4.

In the figure: 1. a heat exchange unit; 11. a box body; 111. a smoke inlet; 112. a smoke outlet; 113. a liquid discharge port; 114. an air inlet; 115. an air outlet; 12. a support; 13. an end plate; 14. a heat exchange pipe; 15. a spraying device; 16. a liquid level meter; 17. a flange plate; 2. a fan; 3. an air supply cover; 4. an air outlet cover; 5. a connecting pipe; 6. a water tank.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.

As shown in fig. 1, a bottom mounting support 12 of a heat exchange unit 1 of a flue gas waste heat recovery exchanger is arranged on the ground to support the heat exchange unit 1, the front end and the rear end of a box 11 of the heat exchange unit 1 are opened to form an air inlet 114 and an air outlet 115 respectively, a fan 2 is connected with the air inlet 114 through an air supply cover 3, so that the fan 2 inputs fresh air and cold air into the heat exchange unit 1, and the rear end air outlet 115 is connected with an air outlet cover 4, so that hot air after heat exchange in the heat exchange unit 1 is discharged.

As shown in fig. 1 to 5, the flue gas waste heat recovery exchanger of the present invention is formed by connecting at least one section of heat exchange unit 1, and can flexibly adapt to equipment with different smoke discharge amounts by increasing or decreasing the number of the heat exchange units 1, and is also convenient for transportation. The heat exchange unit 1 of this embodiment sets up to three, and 11 both sides of box end periphery extension sets up flange plate 17, and two adjacent heat exchange unit 1 realize connecting fixedly through welding between two adjacent flange plates 17, and it is very convenient to install. The end plates 13 are welded and fixed at the air inlet 114 and the air outlet 115 of the box body 11, the outer side faces of the end plates 13 are retracted 3-5mm away from the edge of the box body 11, the end plates 13 are prevented from protruding to influence the installation connection of the heat exchange units 1, the heat exchange tubes 14 of the previous heat exchange unit 1 and the heat exchange tubes 14 of the next heat exchange unit 1 are not required to be butted during installation, only two adjacent box bodies 11 are required to be connected in a sealing mode, the installation is simpler and more convenient, and meanwhile air leakage and water leakage can be avoided.

As shown in fig. 1, 4 and 5, a plurality of heat exchange tubes 14 are horizontally arranged in the box body 11, the cross section of each heat exchange tube 14 is rectangular or long-runway type, the long central axis of each heat exchange tube is vertical to the bottom surface of the box body 11, and compared with the heat exchange tubes of the existing tube-plate heat exchanger which are arranged in a honeycomb manner, the top of the heat exchange tube is more convenient to spray cleaning liquid for washing. The end plate 13 is provided with a through hole corresponding to the heat exchange tube 14, the opening of the heat exchange tube 14 is connected with the through hole of the end plate 13, so that the heat exchange tube 14 is communicated with the air inlet 114 and the air outlet 115, and cold air blown out by the fan 2 can be blown into the next heat exchange unit 1 from the previous heat exchange unit 1. The top of the box body 11 is provided with a smoke inlet 111 and a smoke outlet 112, the last smoke outlet 112 of two adjacent heat exchange units 1 is connected with the next smoke inlet 111 through an arc-shaped connecting pipe 5, smoke enters the box body 11 of the last heat exchange unit 1 from the last smoke inlet 111, then the smoke ascends to enter the connecting pipe 5 from the last smoke outlet 112 and enters the next smoke inlet 111 along the pipe wall, so that the smoke enters the box body 11 of the next heat exchange unit 1, the transportation track is circulated until the smoke is discharged from the smoke outlet 112 of the last heat exchange unit 1, the transmission direction of the smoke can be oriented by the connecting pipe 5 is increased, the heat exchange is more sufficient, and the heat exchange effect is improved.

When the heat exchanger is in practical use, high-temperature harmful flue gas is discharged from the upper-stage equipment and enters the flue gas waste heat recovery exchanger, the flue gas flows in the box body 11 outside the heat exchange tube 14 and transfers heat energy to the heat exchange tube 14, cold air sent out by the fan 2 is conveyed in the heat exchange tube 14, the heat exchange tube 14 conducts the heat energy to the cold air to realize heat exchange, and finally, the hot air is output from the air outlet cover 4 and conveyed to the lower-stage equipment.

As shown in fig. 1, fig. 2, fig. 4 and fig. 5, a spray device 15 is arranged at the top of the inner cavity of the box body 11 of the heat exchange unit 1, a liquid outlet 113 is formed at the bottom of the inner cavity, and the liquid outlet 113 and the spray device 15 are externally connected with a water tank 6. Usually can be irritated a small amount of water or cleaning solution in the box 11, can soak stubborn dirt of washing in the box 11 and the outer pipe wall of heat exchange tube 12, but the flue gas flows water or cleaning solution of stirring above the liquid level, further make the dirt peel off, spray set 15 draws clean water or cleaning solution and blowout in the water tank 6, can wash the dirt impurity that the flue gas remained at its surface, set up level gauge 16 in the box 11 and be used for monitoring the liquid level, when the liquid level is accumulated to 1/2~2/3 of box height in the box 11, open leakage fluid dram 113 and discharge waste water into water tank 6, realize waste water recycle.

During the in-service use, flue gas waste heat recovery interchanger is full-automatic online cleaning, and need not to suspend flue gas waste heat recovery work, because be independent between each heat transfer unit 1, can realize heat exchange simultaneously and wash and flowing back function, if the flue gas gets into next back from preceding heat transfer unit 1, preceding heat transfer unit 1 can spray and wash and flowing back, and remaining heat transfer unit 1 still continues the heat exchange, and preceding heat transfer unit 1 can put into heat exchange work immediately after 15-20 minutes's washing, improves work efficiency.

The foregoing description is illustrative of the present invention and is not to be construed as limiting thereof, as the invention may be modified in any manner without departing from the spirit thereof.