Heat exchanger convenient to clean efficiently

Abstract

The heat exchanger convenient to clean efficiently comprises two heat exchanger box bodies, an upper air channel and a lower air channel of each heat exchanger box body are of two box body structures which are distributed up and down, the upper air channels and the lower air channels are connected through wall plates to form fresh air channels in a surrounding mode, and heat exchange assemblies are arranged in the fresh air channels. The lower air ducts of the two heat exchanger box bodies are communicated to form a heat exchanger; according to the heat exchanger, the scheme that hot waste gas flows from the upper portion to the upper portion is adopted, the hot waste gas and flushing water flow in the first heat exchanger box body flow in the same direction, flushing liquid can more powerfully impact dirt attached to the inner wall of the heat exchange pipe by means of flowing inertia of the waste gas, dirt accumulation is effectively removed, and the high heat transfer efficiency of the heat exchange pipe is maintained.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of energy, and relates to heat exchange equipment, in particular to a heat exchanger convenient for efficient cleaning. BACKGROUND

[0002] The cutting, sewing, ironing and other links of a garment factory, the carding, hot pressing and other processes of a felt factory and the dyeing, drying and other processes of a printing and dyeing factory all need a large amount of heat energy. Waste heat recovery and utilization can reuse part of the waste heat for the production process, such as preheating raw materials, heating water or air and the like, which can effectively save energy and improve economic benefits. The use of waste heat reduces the dependence on traditional fossil energy (such as coal and natural gas), thereby reducing the emission of greenhouse gases such as carbon dioxide generated by burning these energy sources. Direct discharge of waste heat by a factory can cause the surrounding environment temperature to rise, resulting in heat pollution. Waste heat recovery can reduce the waste heat discharge temperature and reduce the impact on the surrounding ecological environment. Through waste heat utilization, an enterprise can reduce the dependence on external energy and reduce energy procurement costs.

[0003] At present, waste heat recovery usually uses a heat exchanger to realize flue gas temperature reduction by convection of high-temperature flue gas and low-temperature air, and preheats the low-temperature air entering the factory. For a garment factory, the waste heat flue gas generated in the cutting and ironing processes contains fabric fibers, hot melt adhesive and the like; for a felt factory, the waste heat flue gas contains wool fibers, chemical adhesives and the like; and for a printing and dyeing factory, the waste heat flue gas contains dyes, additives and fiber impurities. These viscous substances are easy to accumulate in the heat exchanger pipeline, reducing the heat exchange area and increasing the fresh air resistance. Once the heat exchanger is blocked, the cleaning work is very difficult. Due to the viscosity of the viscous substances, the conventional cleaning method may not be effective. It is difficult to remove these viscous substances by using simple water flushing, and chemical cleaning methods need to be used, but the selection of the chemical cleaning agent needs to consider the corrosiveness to the heat exchanger material and the waste liquid treatment problem after cleaning.

[0004] To avoid the problem, a flushing mechanism is usually designed in the heat exchanger to periodically flush the tube. In the design of the tube cleaning mechanism of the heat exchanger, when the flushing gas flow is opposite to the flow direction of the medium during normal operation (counter flow), complex new air mechanics phenomena will occur. Normally, the new air (such as hot process air or cooling air) during the operation of the heat exchanger has a certain flow direction and speed in the tube. During the cleaning process, the steam used for cleaning enters the heat exchange tube in the opposite direction as the flushing gas flow. Due to the counter flow, the energy distribution of the cleaning steam is disturbed. After entering the heat exchange tube, part of the energy of the steam will be used to overcome the resistance of the original new air and the pressure generated by the reverse flow. This reduces the impact force and penetration force of the steam on the dirt. In the case of counter flow, the cleaning steam cannot effectively penetrate to the junction of the dirt and the tube wall, resulting in that some areas where the dirt is located cannot be fully covered by the steam. Moreover, the counter flow will cause the dirt to be redistributed in the tube. The cleaning steam is washed away, so that it stays in the heat exchange tube for too short a time. Some dirt that has been loosened may be carried to other positions under the action of the counter flow and re-deposited on the tube wall that has not been cleaned, resulting in incomplete cleaning. Practical new type content

[0005] In view of the deficiencies in the prior art, the purpose of the present application is to provide a heat exchanger convenient for efficient cleaning, which realizes efficient cleaning of the tube and improves the heat exchange efficiency of the heat exchanger.

[0006] The present application is achieved by the following technical solutions:

[0007] A heat exchanger convenient for efficient cleaning, comprising two heat exchanger boxes, each heat exchanger box comprising an upper air duct, a lower air duct and a new air duct;

[0008] The upper air duct and the lower air duct of a single heat exchanger box are two box structures distributed above and below, and the new air duct is surrounded by the wall plates connected between the upper air duct and the lower air duct, and a heat exchange assembly is arranged in the new air duct; the hot medium inlet and the hot medium outlet of the heat exchange assembly are respectively communicated with the upper air duct and the lower air duct, and a new air inlet and a new air outlet are respectively arranged in the new air duct in the horizontal direction; the lower air ducts of the two heat exchanger boxes are communicated, and the new air ducts are communicated to form a heat exchanger; a heat exchange assembly flushing mechanism is arranged in the upper air duct of the heat exchanger box, and the flushing mechanism is used to flush the impurities and oil stains attached to the inside of the heat exchange assembly;

[0009] After the hot exhaust gas enters the upper air duct of the first heat exchanger box of the heat exchanger, the hot exhaust gas is heated by the heat exchange assembly of the first heat exchanger box and the new air entering through the new air duct, and then enters the lower air duct of the first heat exchanger box. Then, the hot exhaust gas enters the second heat exchanger box through the lower air duct of the second heat exchanger box, and is heated by the heat exchange assembly of the second heat exchanger box and the new air entering through the new air duct. Finally, the hot exhaust gas is discharged into the exhaust gas channel through the upper air duct of the second heat exchanger box.

[0010] Further, the two heat exchanger boxes are connected to form a fresh air channel, the fresh air channel in the second heat exchanger box is used as a fresh air inlet, and the fresh air channel in the first heat exchanger box is used as a fresh air outlet.

[0011] Further, the heat exchange assembly comprises a plurality of heat exchange pipes arranged vertically, and the two ends of the heat exchange pipes are communicated with the upper air duct and the lower air duct, respectively.

[0012] Further, the heat exchange pipe is a straight pipe structure with a smooth inner wall.

[0013] Further, the flushing mechanism comprises a flushing pipe arranged horizontally and a plurality of flushing branch pipes arranged horizontally and communicated with the flushing pipe, and a wastewater pipeline is arranged in the lower air duct; the flushing branch pipes are arranged above the plurality of heat exchange pipes, the bottom of each flushing branch pipe is provided with a spray head, and each spray head is opposite to one heat exchange pipe.

[0014] Further, the heat exchange pipe is provided with fins on the outer surface.

[0015] Further, the fins are flat fins, corrugated fins or louvered fins.

[0016] Further, a plurality of small holes are arranged on the fins.

[0017] Further, an inspection opening is arranged on one side of the lower air duct of the heat exchanger box.

[0018] The heat exchanger has the following beneficial effects:

[0019] The heat exchanger has the following beneficial effects:

[0020] This utility model's heat exchanger adopts a top-in, top-out design for hot waste gas. Within the first heat exchanger housing, the hot waste gas and flushing water flow in the same direction. This co-current flushing ensures the flushing medium is evenly distributed within the heat exchange tubes, propelling it along the tube walls comprehensively. This avoids uneven localized turbulence caused by backflow, guaranteeing consistent cleaning results. The flushing liquid, aided by the inertia of the waste gas flow, more effectively impacts the dirt adhering to the inner walls of the heat exchange tubes. The drag force of the waste gas further washes away oil and impurities adhering to the heat exchange components, effectively removing dirt buildup and maintaining high heat transfer efficiency of the heat exchange tubes.

[0021] A heat exchange component flushing mechanism is also installed in the upper air duct of the second heat exchanger housing to clean the heat exchange components inside the second heat exchanger housing.

[0022] To improve heat exchange performance, fins are provided on the outer surface of the heat exchange tube. The fins have densely packed small holes, which increase the flow channels of fresh air, allowing the fresh air to come into contact with the fin surface. This also promotes the turbulence of the fresh air, improves heat transfer efficiency, and reduces the weight of the fins. Attached Figure Description

[0023] Figure 1 This is a front view of a single heat exchanger housing in this utility model;

[0024] Figure 2 This is a side view of a single heat exchanger housing in this utility model;

[0025] Figure 3 The three-dimensional structure of a single heat exchanger housing in this utility model Figure 1 ;

[0026] Figure 4 for Figure 3 Enlarged view of a portion of point A in the middle;

[0027] Figure 5 The three-dimensional structure of a single heat exchanger housing in this utility model Figure 2 ;

[0028] In the diagram: 1-upper air duct, 2-lower air duct, 3-fresh air duct, 4-flushing pipe, 5-wastewater pipe, 6-inspection port, 7-heat exchange pipe. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments. The description is for explanation and not limitation of the present invention.

[0030] This utility model provides a heat exchanger that is easy to clean efficiently. It includes two heat exchanger housings connected to each other. Each heat exchanger housing includes an upper air duct 1, a lower air duct 2, a fresh air duct 3, a flushing pipe 4, a wastewater pipe 5, an inspection port 6, and a heat exchange tube 7.

[0031] As shown in Figures 1-5 The upper air duct 1 and the lower air duct 2 of the single heat exchanger box are two box structures distributed in upper and lower directions, the upper air duct 1 and the lower air duct 2 are connected by a wall plate to form a fresh air duct 3, and the heat exchange assembly is arranged in the fresh air duct 3; the heat medium inlet and the heat medium outlet of the heat exchange assembly are communicated with the upper air duct 1 and the lower air duct 2 respectively, the fresh air duct 3 is provided with a fresh air inlet on one side in the horizontal direction and a fresh air outlet on the other side; the lower air ducts 2 of the two heat exchanger boxes are communicated, and the two fresh air ducts 3 are communicated to form a heat exchanger. The fresh air duct 3 in the second heat exchanger box serves as a fresh air inlet, and the fresh air duct 3 in the first heat exchanger box serves as a fresh air outlet.

[0032] After the high-temperature hot exhaust gas of the setting machine enters the upper air duct 1 of the first heat exchanger box of the heat exchanger, the hot exhaust gas is heated by the heat exchange assembly of the first heat exchanger box and the new air that has been heated once and enters the lower air duct 2 of the first heat exchanger box through the fresh air duct 3, then enters the second heat exchanger box through the lower air duct 2 of the second heat exchanger box, and then is heated by the heat exchange assembly of the second heat exchanger box and the low-temperature new air that enters through the fresh air duct 3, and finally is discharged into the exhaust gas channel through the upper air duct 1 of the second heat exchanger box, enters the next purification link, and efficiently recovers the heat in the exhaust gas through twice heat exchange. The low-temperature new air entering the fresh air duct 3 is first heated with the high-temperature hot exhaust gas that has been heated once in the second heat exchanger box, and then the new air is heated with the high-temperature hot exhaust gas in the first heat exchanger box, so that new air with higher grade is obtained, and the heat exchange efficiency is improved.

[0033] The heat exchange assembly flushing mechanism is arranged in the upper air duct 1 of the heat exchanger box, and the flushing mechanism is used for flushing the impurities and oil stains attached to the inside of the heat exchange assembly, so that the inside of the heat exchange assembly is kept clean.

[0034] In the utility model, the hot exhaust gas enters the heat exchange assembly through the upper air duct 1 of the first heat exchanger box, and most of the impurities and oil stains brought in the hot exhaust gas will be attached to the heat exchange assembly in the first heat exchanger box, and the high-temperature heat energy in the exhaust gas is first exchanged with the low-temperature new air in the heat exchange assembly in the first heat exchanger box, so the cleanliness of the heat exchange assembly in the first heat exchanger box is particularly important for its efficient operation. The flow direction of the hot exhaust gas in the first heat exchanger box is from top to bottom, and the flushing mechanism is arranged in the upper air duct 1 and sprays high-temperature water vapor or hot steam from top to bottom along the flow direction of the exhaust gas to flush the inside of the heat exchange assembly. The flushing liquid can rely on the flow inertia of the exhaust gas to more powerfully impact the dirt attached to the inner wall of the heat exchange pipe, and rely on the drag force of the exhaust gas to better flush away the oil stains and impurities attached to the heat exchange assembly, effectively remove the dirt accumulation, and maintain a high heat transfer efficiency of the heat exchange pipe.

[0035] The hot exhaust gas and the flushing water flow in the same direction in the first heat exchanger box, and the same direction flushing can ensure that the flushing medium is uniformly distributed in the heat exchange pipe, and fully advances along the pipe wall, avoiding the problem of local turbulent flow caused by reverse flow, excessive flushing in some areas and insufficient flushing in other areas, and ensuring the consistency of cleaning effect. The heat exchange assembly flushing mechanism is also arranged in the upper air duct 1 of the second heat exchanger box to realize the cleaning work of the heat exchange assembly in the second heat exchanger box.

[0036] As shown in Figure 3 and Figure 4 , the heat exchange assembly is a plurality of vertically arranged heat exchange pipes 7, the two ends of the heat exchange pipe are respectively communicated with the upper air duct 1 and the lower air duct 2, and the heat exchange pipe is a straight pipe structure with a smooth inner wall. When the hot exhaust gas flows in the pipe and the fresh air flows outside the pipe, heat is transferred from the hot exhaust gas to the fresh air through the pipe wall. Because the inner surface is smooth, the hot exhaust gas with impurities and oil stains has relatively small internal flow resistance, especially suitable for scenes with more impurities and oil stains in the exhaust gas.

[0037] The flushing mechanism includes a horizontally arranged flushing pipe 4 and a plurality of horizontally arranged flushing branch pipes communicated with the flushing pipe 4, and a waste water pipe 5 is arranged in the lower air duct 2; the flushing branch pipes are arranged above the heat exchange pipes 7, and each flushing branch pipe is provided with a nozzle at the bottom, each nozzle is opposite to one heat exchange pipe 7 to flush one pipe; the high-temperature and high-pressure flushing liquid is introduced from the flushing pipe 4 to enter each flushing branch pipe from the nozzle to clean the inner wall of the heat exchange pipe 7, and the oil stains and impurities entering the heat exchange pipe 7 along with the hot exhaust gas can flow to the bottom of the lower air duct 2 along with the water flow and air flow in the heat exchange pipe 7, and then be discharged from the waste water pipe 5; in this way, the flushing pipe 4, the flushing branch pipe and the nozzle realize the cleaning of the heat exchange pipe 7 by the flushing mechanism, and reduce the possibility that the oil stains and impurities in the exhaust gas block the heat exchange pipe 7 and affect the heat exchange effect.

[0038] In order to achieve higher heat exchange effect, the outer surface of the heat exchange pipe 7 is provided with fins, the fins are flat and are fixed on the heat exchange pipe by welding or mechanical method, which has simple structure and low processing cost. Alternatively, corrugated fins with corrugated surface can be used, such as sawtooth corrugation, circular corrugation, etc. Alternatively, louver fins similar to louver structure can be used, which can effectively guide the flow of fresh air, and can form strong disturbance when the fresh air passes through the fins, thereby improving the heat exchange efficiency. Small holes are formed on the fins, the existence of the small holes increases the flow channel of the fresh air, so that the fresh air can more fully contact with the surface of the fins, and at the same time, the disturbance of the fresh air is also promoted, the heat transfer efficiency is improved, and the weight of the fins is also reduced.

[0039] The fins increase the heat exchange area, and at the same time, the fins destroy the boundary layer of the fresh air and enhance the turbulence degree of the fresh air. When the fresh air flows through the finned pipe, the flow state of the fresh air becomes more complex due to the existence of the fins, the heat transfer efficiency is improved, and the heat exchange is effectively strengthened through the finned pipe.

[0040] As shown in Figure 5 With the use of the heat exchanger, the heat exchange tube may have problems such as scaling, corrosion, leakage, etc., and the baffle plate may be damaged, which requires regular or irregular internal inspection and treatment. In order to facilitate maintenance, an inspection opening 6 is provided on one side of the lower air duct 2 of the heat exchanger tank, which facilitates the cleaning of the deposited dirt inside the lower air duct 2 and facilitates the entry of maintenance personnel or the use of tools for cleaning.

[0041] The inspection opening 6 is located on one side of the lower air duct 2. In order to prevent air leakage and affect the heat exchange efficiency and air outlet effect of the heat exchanger, the inspection opening is designed to be sealed. Rubber gasket, sealant and other materials are used to ensure the sealing performance after the inspection opening is closed.

Claims

1. A heat exchanger facilitating efficient cleaning, characterized by: The heat exchanger comprises two heat exchanger boxes, each of which comprises an upper air duct (1), a lower air duct (2) and a fresh air duct (3); The upper air duct (1) and the lower air duct (2) of a single heat exchanger box are two box structures arranged in an up-down manner, the upper air duct (1) and the lower air duct (2) are connected by a wall plate to enclose the fresh air duct (3), and a heat exchange assembly is arranged in the fresh air duct (3); the heat medium inlet and the heat medium outlet of the heat exchange assembly are communicated with the upper air duct (1) and the lower air duct (2) respectively, and the fresh air duct (3) is provided with a fresh air inlet and a fresh air outlet in the horizontal direction respectively; the lower air ducts (2) of the two heat exchanger boxes are communicated, and the fresh air ducts (3) are communicated to form a heat exchanger; a heat exchange assembly flushing mechanism is arranged in the upper air duct (1) of the heat exchanger box, and the flushing mechanism is used for flushing the impurities and oil stains attached to the inside of the heat exchange assembly; After the hot waste gas enters the upper air duct (1) of the first heat exchanger box of the heat exchanger, the hot waste gas is heated by the heat exchange assembly of the first heat exchanger box and the fresh air entering through the fresh air duct (3), and then enters the lower air duct (2) of the first heat exchanger box, and then enters the second heat exchanger box through the lower air duct (2) of the second heat exchanger box, and is heated by the heat exchange assembly of the second heat exchanger box and the fresh air entering through the fresh air duct (3), and finally is discharged into the waste gas passage through the upper air duct (1) of the second heat exchanger box.

2. The heat exchanger facilitating efficient cleaning as claimed in claim 1 wherein: The fresh air ducts (3) of the two heat exchanger boxes are communicated to form a fresh air passage, the fresh air duct (3) in the second heat exchanger box serves as a fresh air inlet, and the fresh air duct (3) in the first heat exchanger box serves as a fresh air outlet.

3. The heat exchanger facilitating efficient cleaning as claimed in claim 2 wherein: The heat exchange assembly comprises a plurality of heat exchange pipes (7) arranged in a vertical manner, and the two ends of each heat exchange pipe are communicated with the upper air duct (1) and the lower air duct (2) respectively.

4. The heat exchanger facilitating efficient cleaning as claimed in claim 3 wherein: The heat exchange pipe (7) is a straight pipe structure with smooth inner wall.

5. The heat exchanger facilitating efficient cleaning as claimed in claim 4 wherein: The flushing mechanism comprises a flushing pipe (4) arranged horizontally and a plurality of flushing branch pipes arranged horizontally and communicated with the flushing pipe (4), and a wastewater pipe (5) is arranged in the lower air duct (2); the flushing branch pipes are arranged above the heat exchange pipes (7), the bottom of each flushing branch pipe is provided with a spray head, and each spray head is opposite to one heat exchange pipe (7).

6. The heat exchanger facilitating efficient cleaning as claimed in any one of claims 3 to 5, wherein: Fins are arranged on the outer surface of the heat exchange pipe (7).

7. The heat exchanger facilitating efficient cleaning as claimed in claim 6 wherein: The fins are flat fins, corrugated fins or louvered fins.

8. The heat exchanger facilitating efficient cleaning as claimed in claim 7 wherein: Small holes are arranged on the fins in a dense manner.

9. The heat exchanger facilitating efficient cleaning as claimed in claim 8 wherein: An inspection opening (6) is arranged on one side of the lower air duct (2) of the heat exchanger box.

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