Disclosure of Invention
To the problem that exists among the prior art, the utility model aims to provide an use aluminium as main part heat transfer material's secondary heat exchanger, improve the ability of acid corrosion resistance when reaching the one-level efficiency, reduce the volume, reduce cost improves the not enough of prior art.
In order to achieve the above purpose, the utility model adopts the following technical scheme.
A secondary condensing heat exchanger of a gas fired water heating apparatus comprising: the shell is provided with an air inlet, an air outlet and a condensed water outlet which are arranged on the shell, and the heat exchange body is arranged in the shell; the heat exchanger is characterized in that the heat exchanger is an aluminum part and comprises a water flow channel, barbed sheets and steps which are formed together, the barbed sheets are arranged around the water flow channel, and the steps are positioned at two ends of the water flow channel and penetrate out of the shell respectively.
More preferably, the shell comprises a shell, an upper cover, a front fixing plate and a rear fixing plate, the shell is in buckled connection with the upper cover, the front fixing plate and the rear fixing plate are installed between the shell and the upper cover, and two ends of the water flow channel penetrate out of the front fixing plate and the rear fixing plate through corresponding steps.
More preferably, the air inlet is located at the lower side of the housing, and the air outlet is located at the top of the upper cover.
More preferably, the bottom of the housing is an inclined surface, and the condensed water outlet is located at a lower end of the inclined surface.
More preferably, a baffle is arranged in the upper cover, and the baffle is arranged close to the air outlet and is in contact with the heat exchange body.
More preferably, the number of the heat exchange bodies is at least two, and the water flow channels of the heat exchange bodies are connected in series.
More preferably, an expansion pipe is arranged in the water flow channel, and the outer wall of the expansion pipe is in close contact with the inner wall of the water flow channel; the expansion pipe is a copper pipe or an aluminum pipe.
More preferably, the barbed sheet is provided with a plurality of U-shaped grooves, and the direction of each U-shaped groove is in accordance with the axial direction of the water flow channel.
More preferably, a turbulent spring or a turbulent blade is provided in the water flow passage.
More preferably, a flue gas temperature sensor or a flue gas temperature controller is arranged corresponding to the air outlet, and a condensed water liquid level detection needle is arranged corresponding to the condensed water outlet.
The utility model has the advantages that: 1) the thermal efficiency is high: the heat exchange body is an aluminum part, the heat conductivity coefficient of the heat exchange body is between 200 and 228W/m and is more than 10 times of the heat conductivity coefficient of the stainless steel, namely 17.5W/m, so that the heat exchange efficiency is better; in addition, through the optimized design of the heat exchange stabbing sheet and the upper cover, the fluid form of the high-temperature flue gas is changed, the high-temperature flue gas is forced to pass through the heat exchange body, and the heat exchange efficiency is further improved; and a scheme of placing a turbulent spring, a turbulent sheet and the like in the water pipe is adopted, so that the fluid form at the water flow side is changed, and the heat exchange efficiency is improved. Through experimental actual measurement, the gas wall-hanging stove or the gas water heater of configuration this technical scheme's secondary heat exchanger, the thermal efficiency can reach more than 105%, is higher than the 99% requirement of national first-class efficiency greatly. 2) Acid corrosion resistance: the heat exchange body adopts the integrated into one piece structure, and inside does not have the welding point for the metal that contacts with high temperature flue gas and comdenstion water only is the aluminium material after the passivation treatment, consequently has very good corrosion resisting capability to the acid condensate water, does not have the risk of being corroded, influencing the reliability. 3) The volume is small: compared with a stainless steel secondary heat exchanger, the heat conductivity coefficient of the selected aluminum material is 10 times of that of stainless steel, so that the heat exchange efficiency of the primary energy efficiency can be realized only by a smaller heat exchange area, and the volume of the whole secondary heat exchanger is less than 50% of that of the stainless steel secondary heat exchanger. 4) The cost is lower: because the utility model discloses an aluminum material processing or casting only need still material, and production technology does not need the support of brazing the production line simultaneously, therefore material cost, manufacturing cost all than the stainless steel scheme lower, and the defective index is also lower simultaneously, therefore the combined cost is lower, has bigger economic value.
Detailed Description
In the description of the present invention, it should be noted that, for the orientation words, if there are terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the orientation and positional relationship indicated are based on the orientation or positional relationship shown in the drawings, and only for the convenience of describing the present invention and simplifying the description, it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and not be construed as limiting the specific scope of the present invention.
In the present invention, unless otherwise expressly specified or limited, the terms "assembled", "connected", and "connected", if any, are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; or may be a mechanical connection; the two elements can be directly connected or connected through an intermediate medium, and the two elements can be communicated with each other. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific situations.
In the present application, unless otherwise specified or limited, "above" or "below" a first feature may include the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other through another feature therebetween. Also, the first feature being "above," "below," and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply an elevation which indicates a level of the first feature being higher than an elevation of the second feature. The first feature being "above", "below" and "beneath" the second feature includes the first feature being directly below or obliquely below the second feature, or merely means that the first feature is at a lower level than the second feature.
The following description will be further made in conjunction with the accompanying drawings of the specification, so that the technical solution and the advantages of the present invention are clearer and clearer. The embodiments described below are exemplary and are intended to be illustrative of the present invention, but should not be construed as limiting the invention.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, or may be learned by practice of the invention.
As shown in fig. 1 and 2, the secondary condensation heat exchanger of the gas water heating device comprises a shell 1, a heat exchange body assembly 2 and an upper cover 3, wherein the shell 1 and the upper cover 3 are connected in a buckling manner, and the heat exchange body assembly 2 is wrapped inside to form a sealed cavity.
The shell 1 is formed by injection molding of high-temperature-resistant, acid-resistant and high-strength plastic or die casting of other metal materials such as aluminum materials, an air inlet 1-1 and a condensate water outlet 1-2 are formed in the shell 1, high-temperature smoke coming out of the primary heat exchanger enters the secondary heat exchanger from the air inlet 1-1, and condensate water generated after the high-temperature smoke is cooled is completely received by the shell 1 and is discharged through the condensate water outlet 1-2.
The upper cover 3 is made of plastic having high temperature resistance, acid resistance and strength, or other metal materials such as aluminum, like the case 1. The upper cover 3 is provided with an air outlet 3-1, and high-temperature flue gas is discharged into the atmosphere through the air outlet 3-1 after being subjected to heat exchange and temperature reduction.
Referring to fig. 3 and 4, the heat exchanger assembly 2 is a whole formed by assembling and welding as a heat exchange main body, and comprises a water inlet pipe 2-1, a water outlet pipe 2-2, a front fixing plate 2-3, a rear fixing plate 2-4, a heat exchanger 2-5, a long U-shaped pipe 2-6 and a short U-shaped pipe 2-7.
The water inlet pipe 2-1, the water outlet pipe 2-2, the long U-shaped pipe 2-6 and the short U-shaped pipe 2-7 are copper tubes or aluminum tubes. The heat exchange bodies 2-5 are cast aluminum pieces. The front fixing plate 2-3 and the rear fixing plate 2-4 are made of aluminum plate materials, or other metals resistant to acid corrosion, or other metals which are not resistant to acid corrosion, and are subjected to surface treatment to achieve the purpose of having sufficient acid corrosion resistance. The front and rear fixing plates are used for fixing and combining a plurality of heat exchange bodies.
Here, the front fixing plate 2-3 and the rear fixing plate 2-4 are provided to facilitate assembly of the heat exchanger 2-5 with the housing 1 and the upper cover 3. In other embodiments, the front fixing plate 2-3 and the rear fixing plate 2-4 may be omitted, and the heat exchanger 2-5 may be directly connected to the housing 1 and the upper cover 3; the present embodiment is not limited.
The structure of the heat exchange body 2-5 is shown by combining with figure 5, and comprises a water flow channel 2-5-1, barbed sheets 2-5-2, steps 2-5-3 and a plurality of barbed sheets 2-5-2 which are arranged and combined in parallel, wherein the water flow channel 2-5-1 vertically penetrates through all the barbed sheets 2-5-2, the structure can be integrally formed by casting, and an integral structure with one barbed sheet and a middle water flow channel which are parallel to each other can be formed by machining a blank of a section bar. Because the water flow channel is integrally formed, no welding or clearance exists between the thorn pieces 2-5-2 and the water flow channel 2-5-1, so that the problem that welding points are corroded does not exist, and the heat efficiency is improved. The thorn pieces 2-5-2 are provided with a plurality of U-shaped grooves 2-5-4, on one hand, the U-shaped grooves can be used as screw holes for connecting and fixing the heat exchange bodies 2-5 on the front fixing plate 2-3 and the rear fixing plate 2-4, on the other hand, the U-shaped grooves can cause disturbance when high-temperature flue gas passes through the gaps between the thorn pieces 2-5-2, change the motion state of air flow and be beneficial to improving the heat efficiency. The steps 2-5-3 are used for wrapping the water inlet pipe 2-1, the water outlet pipe 2-2 and the long U-shaped pipe 2-6, and the steps 2-5-3 are inserted into round holes of the front fixing plate 2-3 and the rear fixing plate 2-4 in assembly, so that the pipes are not exposed in a cavity inside the heat exchanger, and the risks that the pipes are contacted with high-temperature smoke and condensate water and corroded are avoided.
It should be noted that, in practical application, the long U-shaped pipe 2-6, the water inlet pipe 2-1 and the water outlet pipe 2-2 are not needed, and the pipe expanding process is not needed, but the short U-shaped pipe 2-7 is directly welded at two ends of the water flow channel 2-5-1 on the heat exchange body 2-5, and the water inlet pipe 2-1 and the water outlet pipe 2-2 are also directly welded on the water flow channel 2-5-1, so that a single water flow channel can be formed.
It should be noted that the barbed sheets 2-5-2 in the present embodiment are square and have a four-corner chamfered structure, but not limited to this shape, and in practical applications, they may be round, oval, or other shapes, and the technical point is that the barbed sheets 2-5-2 and the water flow channels 2-5-1 are integrally formed without welding points, rather than the shape of the barbed sheets 2-5-2.
Referring to fig. 6, in the embodiment, the number of the heat exchanging bodies 2 to 5 is 8, but the number is not limited to 8 in practical application, and the number may be selected according to the magnitude of the heat exchanging power.
It should be noted that, in the present embodiment, the plurality of heat exchanging bodies 2-5 are arranged and combined in an "X" shape, but in practical application, there may be more combinations, which may be combinations of "field" or "day", etc.
It should be noted that the heat exchanger body assembly 2 is an assembly formed by assembling and welding, and the manufacturing process is as follows: after the heat exchange bodies 2-5 are processed or cast, the heat exchange bodies are arranged according to a certain number of arrangement and combination modes, the positions of the heat exchange body combinations are fixed by the corresponding front fixing plate 2-3 and the rear fixing plate 2-4, and then the heat exchange bodies 2-5, the front fixing plate and the rear fixing plate are installed and connected into an assembly component by screws; then, a water inlet pipe 2-1, a water outlet pipe 2-2 and a long U-shaped pipe 2-6 are inserted into each water flow channel 2-5-1, the outer diameter of the pipelines is expanded by pipe expanding equipment, so that the outer walls of the pipelines are tightly attached to the inner walls of each water flow channel 2-5-1, and a good heat conduction effect is achieved; finally, turbulent springs and turbulent flow sheets are placed in the pipelines as a conventional heat exchange enhancement measure, and then short U-shaped pipes 2-7 are welded at the other ends of the pipelines in a certain sequence, so that all the pipelines and the U-shaped pipes are connected in series to form a single channel with only one water inlet and one water outlet.
The heat exchanger body assembly 2 is assembled and welded to be an independent assembly and is buckled between the shell 1 and the upper cover 3, and the shell 1 and the upper cover 3 are connected and fixed through screws, so that a finished product of the secondary heat exchanger is formed.
Referring to fig. 7, a mounting connection hole 2-3-1 of a flue gas temperature sensor or a flue gas temperature controller is further provided at a position corresponding to the air outlet, so as to monitor the temperature of the flue gas, thereby performing overheat protection on the wall-mounted boiler or the gas water heater. And a condensate water liquid level detection needle mounting step 1-3 is arranged at the position corresponding to the condensate water outlet. When the device is needed, two mounting holes can be machined in the mounting steps 1-3, and two liquid level detection needles are mounted and used for detecting whether a condensed water channel is blocked or not, so that condensed water is prevented from overflowing from the air inlet 1-1 due to channel blocking, and the wall-mounted furnace or the gas water heater is prevented from being damaged by the condensed water, and even personal injury is avoided.
The flow direction of the high-temperature flue gas formed in the secondary heat exchanger is shown as an arrow in figure 8, after the secondary heat exchanger is assembled in a boiler or a gas water heater, the high-temperature flue gas (with the temperature of 110-180 ℃) subjected to heat exchange by the primary heat exchanger enters the secondary heat exchanger from the air inlet 1-1, the air inlet direction is parallel to the barbed sheets 2-5-2, the high-temperature flue gas is automatically divided into a plurality of paths, and the high-temperature flue gas flows in gaps among the barbed sheets 2-5-2. Finally, the air leaves the secondary heat exchanger from the air outlet 3-1 and is discharged into the atmosphere. And the water flow enters the heat exchanger from the water inlet pipe 2-1, passes through the whole single channel and finally flows out of the secondary heat exchanger from the water outlet pipe 2-2.
When the high-temperature flue gas respectively flows through each heat exchange body 2-5, the heat in the high-temperature flue gas is absorbed by the thorn pieces 2-5-2 and the water flow channels 2-5-1, then is transmitted to the water inlet pipe 2-1, the long U-shaped pipe 2-6 and the water outlet pipe 2-2, and then is transmitted to the water flowing in the pipe through the water pipes, so that the water absorbs the heat and is heated. After the water pipes are expanded, the outer walls of the water pipes are in close contact with the inner part of the water flow channel 2-5-1, so that the heat exchange efficiency between the whole heat exchange body and the water flow in the pipes is good.
When high-temperature flue gas flows through the heat exchange body 2-5, the U-shaped grooves 2-5-4 on the thorn pieces 2-5-2 disturb the high-temperature flue gas, change the fluid form of the high-temperature flue gas, and are beneficial to strengthening heat exchange and improving the heat efficiency. The springs and the turbulence pieces in the whole water flow pipeline, such as the water inlet pipe 2-1, can disturb the water flow and change the fluid form of the water flow, and are favorable for strengthening heat exchange. The position of the upper cover 3 close to the air outlet 3-1 is provided with a baffle plate, so that high-temperature flue gas is prevented from directly entering the air outlet 3-1 from the upper left corner without heat exchange, namely the high-temperature flue gas is forced to flow from the position of the heat exchange body 2-5, and heat is favorably and fully absorbed by the heat exchange body 2-5.
In addition, in design, the water inlet pipe 2-1 is arranged at the position of the air outlet 3-1 with the lowest flue gas temperature, the water outlet pipe 2-2 is arranged at the position of the air inlet 1-1 with the highest flue gas temperature, the temperature of water flow entering the heat exchanger is the lowest, and the temperature of water flow flowing out of the water outlet pipe 2-2 is the highest, so that the directions of high-temperature flue gas and low-temperature water flow are in reverse directions, and the heat exchange effect can be maximized.
Through experimental measurement, the heat exchanger provided by the embodiment can improve the heat efficiency of a wall-mounted gas boiler or a gas water heater to more than 105%, and is 6% higher than the standard of first-level energy efficiency of 99%.
After the high-temperature flue gas is cooled, water vapor in the high-temperature flue gas is condensed into condensed water and is collected at the bottom of the secondary heat exchanger, and the bottom is a plane which is inclined downwards towards the condensed water outlet 1-2, so that the finally condensed water is collected and discharged from the condensed water outlet 1-2 without accumulating and staying at the bottom of the secondary heat exchanger.
Compared with the prior art, the secondary condensation heat exchanger that this embodiment provided has following technological effect: 1) The thermal efficiency is high: the heat conductivity coefficient of the selected aluminum material is between 200 and 228W/m and is more than 10 times of the heat conductivity coefficient of the stainless steel, namely 17.5W/m, so that the aluminum material has more excellent heat exchange efficiency; in addition, through the optimized design of the heat exchange stabbing sheet and the upper cover, the fluid form of the high-temperature flue gas is changed, the high-temperature flue gas is forced to pass through the heat exchange body, and the heat exchange efficiency is further improved; and a scheme of placing a turbulent spring, a turbulent sheet and the like in the water pipe is adopted, so that the fluid form at the water flow side is changed, and the heat exchange efficiency is improved. Through experimental actual measurement, the gas wall-hanging stove or the gas water heater of configuration this technical scheme's secondary heat exchanger, the thermal efficiency can reach more than 105%, is higher than the 99% requirement of national first-class efficiency greatly. 2) Acid corrosion resistance: because the metal in the heat exchanger contacted with the high-temperature flue gas and the condensed water only is made of the aluminum material after the passivation treatment, no welding point is arranged in the heat exchanger, and the plastic shell is made of the acid-resistant material, the heat exchanger has excellent corrosion resistance to the acid condensed water, and the risk of being corroded and influencing the reliability does not exist. 3) The volume is small: compared with a stainless steel secondary heat exchanger, the heat conductivity coefficient of the selected aluminum material is 10 times of that of stainless steel, so that the heat exchange efficiency of the primary energy efficiency can be realized only by a smaller heat exchange area, and the volume of the whole secondary heat exchanger is less than 50% of that of the stainless steel secondary heat exchanger. 4) The cost is lower: because the technical scheme adopts aluminum material processing or casting, only less materials are needed, and the production process does not need the support of a brazing production line, the material cost and the manufacturing cost are lower than those of the stainless steel scheme, and the defective rate is also lower, so the comprehensive cost is lower, and the economic value is higher.
It will be understood by those skilled in the art from the foregoing description of the structure and principles that the present invention is not limited to the specific embodiments described above, and that modifications and substitutions based on the known art are intended to fall within the scope of the invention, which is defined by the claims and their equivalents. The details not described in the detailed description are prior art or common general knowledge.