Full-premixing condensation type heat exchanger

Abstract

The utility model provides a full-premixing condensation type heat exchanger, relates to the technical field of gas water heating devices, and solves the technical problems that spiral coils of an existing condensation type heat exchanger are mutually supported in a spatial configuration mode to form gaps to disturb smoke, and disturbance of the coils is unstable. The heat exchanger comprises a box body and a spiral flat coil pipe which is arranged in the box body and used for introducing cooling water to exchange heat with flue gas, the spiral flat coil pipe comprises threaded protrusions which are distributed on one side of the flat pipe and used for protruding to form threaded grooves, and the other side of the spiral flat coil pipe is arranged to be a supporting plane used for supporting the threaded protrusions. Through the spiral flat coil pipe, the contact area of cooling water and flue gas is enlarged, and the heat exchange efficiency is improved; when the cooling water is cooled, the smoke forms disturbance in the spiral groove and disturbs the smoke around the spiral flat coil pipe, so that the smoke flow path is increased, and the smoke retention time is prolonged, so that the cooling water fully absorbs latent heat in the smoke; the spiral grooves do not coincide with one another, so that flue gas flowing is not affected, and the stability is higher while the flue gas is disturbed.

Description

Technical Field

[0001] The utility model relates to the technical field of gas water heaters, in particular to a full premix condensing heat exchanger. Background Art

[0002] The condensation technology used in the fully premixed condensing wall-mounted boiler can recycle the waste heat in the flue gas, and its combustion method is fully premixed ratio adjustment. The exhaust temperature of the condensing wall-mounted boiler can be reduced to about 40°C, and the latent heat of water vapor in the flue gas can be fully absorbed and utilized. The existing fully premixed condensing heat exchanger is most commonly used in gas water heaters. The high-temperature flue gas generated by the combustion of mixed gas passes through the fully premixed condensing heat exchanger to heat the water flowing through the fully premixed condensing heat exchanger. The high-temperature flue gas is cooled until it condenses, and the heated water flows into the gas water heater and continues to be heat exchanged by the heat exchanger. Most of its heat exchange tubes are metal tubes with smooth surfaces, and flat tubes are wound into spiral coils. The flat tube coils are arranged horizontally, and the distance between the flat tubes of the coils is ensured by a fixed distance device. The distance is too small, and the gap is very uneven. In addition, it is a simple one-dimensional structure channel structure, so that the sulfide structure precipitated after the flue gas is condensed will cause serious blockage of the tube gap channel and fail, causing major technical accidents. Moreover, due to its unreasonable structure, the flue gas flow field is seriously uneven and the deviation is serious. The lower half of the horizontally arranged coil hardly participates in heat exchange, and the utilization rate is very low, which seriously affects the heat exchange effect.

[0003] Therefore, a "basket"-shaped three-dimensional variable space condensing gas water heater is proposed in the patent with publication number CN111998535A. This application improves the heat exchange efficiency of the heat exchange module by changing the spatial structure of the coil, optimizes the flow field on the flue gas and water sides, reduces local dead angles, makes the flow fields on both sides more uniform, and is not easy to scale, extends the maintenance cycle of the heat exchanger, and reduces the difficulty of maintenance. However, this application omits the gap-fixing devices such as support cards between the coils because the spatial structure of the flat coil supports the gap in the middle. Although the spatial structure of the coil can support each other, the support strength is also lower and the reserved gap is also smaller. The disturbance in the horizontal direction caused by it is easy to cause the coil gap to change, resulting in further uneven flow of the fluid between the coils, affecting the heat exchange effect. Utility Model Content

[0004] The utility model aims to provide a fully premixed condensing heat exchanger to solve the technical problems that the spiral coils of the existing condensing heat exchangers adopt a spatial configuration to support each other to form gaps that disturb the flue gas and the coil disturbance is unstable.

[0005] The embodiments of the present invention are implemented by the following technical solutions:

[0006] A fully premixed condensing heat exchanger includes a box body and a spiral flat coil arranged in the box body for passing cooling water and flue gas for heat exchange. The spiral flat coil includes a threaded protrusion distributed on one side of the flat tube for protruding to form a threaded groove, and the other side of the spiral flat coil is set as a supporting plane for supporting the threaded protrusion.

[0007] Preferably, a heat exchange chamber for exchanging heat with flue gas is provided on the outer side of the spiral flat coil, and the heat exchange chamber is provided with a smoke inlet for introducing high-temperature smoke and a smoke outlet for discharging low-temperature smoke; the smoke inlet is staggered with the smoke outlet, and the smoke flow direction is opposite to the cooling water flow direction.

[0008] Preferably, it also includes a fan for blowing mixed air, a burner for burning gas to generate smoke, and a PLC controller for controlling the amount of gas introduced, and the smoke port of the burner is connected to the smoke inlet.

[0009] Preferably, the PLC controller is provided with a gas pipe for connecting the gas and a gas valve for controlling the mixing ratio of the gas.

[0010] Preferably, the fan and the gas pipe are connected to a mixing chamber for mixing gas and air, and the mixing chamber is connected to the burner.

[0011] Preferably, the thread groove and the thread protrusion are arranged obliquely along the axial direction of the spiral flat coil.

[0012] Preferably, the spiral flat coil further includes a cold water inlet for connecting to a cold water pipe and a hot water outlet for connecting to a hot water pipe.

[0013] By adopting this technical solution, the contact area between cooling water and flue gas can be expanded through the spiral flat coil. The spiral flat coil is supported by the supporting plane of the spiral protrusion on the other side of the coil to form a relatively stable spiral groove. The flue gas flows through the spiral groove, increasing the contact area between the flue gas and cooling water. The flue gas will form disturbances in the spiral groove, disturbing the flue gas around the spiral flat coil, increasing the flue gas flow, and prolonging the flue gas residence time, so that the cooling water can fully absorb the latent heat in the flue gas.

[0014] The spiral protrusion is supported on a supporting plane, so the shaking of the spiral flat coil caused by the disturbance of the smoke flow will not cause the spiral grooves to overlap and affect the smoke flow. The stability is also higher while disturbing the smoke.

[0015] The technical solution of the embodiment of the utility model has at least the following advantages and beneficial effects:

[0016] 1. The utility model uses spiral flat coils to expand the contact area between cooling water and flue gas and improve heat exchange efficiency;

[0017] 2. The smoke of the utility model will form disturbances in the spiral grooves, disturbing the smoke around the spiral flat coil, increasing the smoke flow, and prolonging the smoke residence time, so that the cooling water can fully absorb the latent heat in the smoke;

[0018] 3. The spiral grooves of the utility model will not overlap and affect the flow of smoke, and the stability is higher while disturbing the smoke. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of a fully premixed condensing heat exchanger provided in Example 1 of the utility model;

[0021] Figure 2 A schematic diagram of a spiral flat coil test structure of a fully premixed condensing heat exchanger provided in Example 1 of the utility model;

[0022] Figure 3 A schematic diagram of a top view of the spiral flat coil structure of a fully premixed condensing heat exchanger provided in Example 2 of the utility model;

[0023] Icons: 1. Box body; 2. Spiral flat coil; 21. Threaded protrusion; 22. Support plane; 23. Threaded groove; 24. Hot water outlet; 25. Cold water inlet; 31. Hot water pipe; 32. Cold water pipe; 41. Flue gas outlet; 42. Flue gas inlet; 5. Heat exchange chamber; 6. Fan; 7. PLC controller; 71. Gas pipe; 72. Gas valve; 8. Burner; 9. Mixing chamber. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] In the description of the present invention, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is usually placed when used. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Example 1

[0030] A fully premixed condensing heat exchanger comprises a housing 1 and a spiral flat coil 2 arranged in the housing 1 for passing cooling water and flue gas for heat exchange. The spiral flat coil 2 comprises a threaded protrusion 21 distributed on one side of the flat tube for protruding to form a threaded groove 23, and the other side of the spiral flat coil 2 is set as a supporting plane 22 for supporting the threaded protrusion 21.

[0031] In this embodiment, a heat exchange chamber 5 for exchanging heat with flue gas is provided on the outer side of the spiral flat coil 2, and the heat exchange chamber 5 is provided with a smoke inlet 42 for introducing high-temperature smoke and a smoke outlet 41 for discharging low-temperature smoke; the smoke inlet 42 is staggered with the smoke outlet 41, and the flow direction of the smoke is opposite to the flow direction of the cooling water.

[0032] In this embodiment, it also includes a fan 6 for blowing mixed air, a burner 8 for burning gas to generate smoke, and a PLC controller 7 for controlling the amount of gas introduced. The smoke port of the burner 8 is connected to the smoke inlet 42.

[0033] In this embodiment, the PLC controller 7 is provided with a gas pipe 71 for communicating with the gas and a gas valve 72 for controlling the mixing ratio of the gas.

[0034] In this embodiment, the fan 6 and the gas pipe 71 are connected to a mixing chamber 9 for mixing gas and air, and the mixing chamber 9 is connected to the burner 8 .

[0035] Working principle and usage:

[0036] During operation, the contact area between the cooling water and the flue gas is enlarged through the spiral flat coil 2. The spiral flat coil 2 is supported by the supporting plane 22 of the spiral protrusion on the other side of the coil to form a relatively stable spiral groove. The flue gas flows through the spiral groove to increase the contact area between the flue gas and the cooling water. The flue gas will form disturbances in the spiral groove and disturb the flue gas around the spiral flat coil 2, thereby increasing the flue gas flow and prolonging the flue gas residence time, so that the cooling water can fully absorb the latent heat in the flue gas.

[0037] The spiral protrusion is supported on the supporting plane 22. The disturbance caused by the smoke flow will not cause the spiral flat coil 2 to shake, and the spiral grooves will not overlap with each other to affect the smoke flow. The stability is also higher while the smoke is disturbed.

[0038] Example 2

[0039] The only difference between this embodiment and the first embodiment is that, in this embodiment, the thread groove 23 and the thread protrusion 21 are arranged obliquely along the axial direction of the spiral flat coil 2 .

[0040] In this embodiment, the spiral flat coil 2 further includes a cold water inlet 25 for connecting to a cold water pipe 32 and a hot water outlet 24 for connecting to a hot water pipe 31 .

[0041] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fully premixed condensing heat exchanger, comprising a housing (1) and a spiral flat coil (2) arranged in the housing (1) for passing cooling water to exchange heat with flue gas, characterized in that: The spiral flat coil (2) comprises a threaded protrusion (21) distributed on one side of the flat tube and used to protrude to form a threaded groove (23), and the other side of the spiral flat coil (2) is provided as a supporting plane (22) used to support the threaded protrusion (21).

2. A fully premixed condensing heat exchanger according to claim 1, characterized in that: A heat exchange chamber (5) for exchanging heat with flue gas is provided on the outside of the spiral flat coil (2); the heat exchange chamber (5) is provided with a flue gas inlet (42) for introducing high-temperature flue gas and a flue gas outlet (41) for discharging low-temperature flue gas; the flue gas inlet (42) is staggered with the flue gas outlet (41), and the flue gas flow direction is opposite to the cooling water flow direction.

3. A fully premixed condensing heat exchanger according to claim 2, characterized in that: It also includes a fan (6) for blowing in mixed air, a burner (8) for burning gas to generate smoke, and a PLC controller (7) for controlling the amount of gas introduced, wherein the smoke outlet of the burner (8) is connected to the smoke inlet (42).

4. A fully premixed condensing heat exchanger according to claim 3, characterized in that: The PLC controller (7) is provided with a gas pipe (71) for communicating with the gas and a gas valve (72) for controlling the mixing ratio of the gas.

5. A fully premixed condensing heat exchanger according to claim 4, characterized in that: The fan (6) and the gas pipe (71) are connected to a mixing chamber (9) for mixing gas and air, and the mixing chamber (9) is connected to the burner (8).

6. A fully premixed condensing heat exchanger according to any one of claims 1 to 5, characterized in that: The thread groove (23) and the thread protrusion (21) are arranged obliquely along the axial direction of the spiral flat coil (2).

7. A fully premixed condensing heat exchanger according to any one of claims 1 to 5, characterized in that: The spiral flat coil (2) also includes a cold water inlet (25) for connecting to a cold water pipe (32) and a hot water outlet (24) for connecting to a hot water pipe (31).

Images