A waste heat recovery device for gas stove exhaust pipes

Abstract

This invention discloses a waste heat recovery device for a gas stove exhaust pipe, comprising a housing, which is a rectangular box. A heat exchange module is disposed within the housing, comprising an auxiliary cooling module and a cooling module. Air inlets and outlets are provided on the front and rear sides of the housing, with air inlet pipes and outlet pipes fixedly connected to the air inlets and outlets respectively. An additive with thermosensitive activity is introduced into the auxiliary cooling module to accelerate the uniform distribution of heat in the exhaust gas within the housing perpendicular to its direction of movement. Coolant is introduced into the cooling module to cool the high-temperature exhaust gas within the housing. The additive is a thermosensitive agent; the coolant is water; and the cooling module is made of food-grade stainless steel. This invention employs a transverse heat guidance and longitudinal heat recovery method, achieving heat transfer through multiple cooling loops. After staged heating, the water temperature can reach nearly 50°C.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste heat recovery, in particular to a waste heat recovery device and method for a waste pipe of a gas stove. BACKGROUND

[0002] It is known that all gas stoves need to use a blower to continuously blow air into the furnace to increase oxygen supply and completely burn gas as much as possible when in operation to ensure safety. However, even with increased oxygen, it is not 100% certain that the gas is completely burned, and some harmful gases such as carbon monoxide are still discharged. Therefore, all large gas stoves on the market currently use a blower to assist the complete combustion of gas at the burner of the gas stove. The greater the gas stove firepower, the greater the gas consumption and the blower blowing capacity. In the continuous combustion, gas and air are continuously supplied into the furnace, and after combustion, the exhaust gas is continuously discharged through the exhaust pipe (there is a risk of fire and oxygen deficiency if not discharged in time). The exhaust gas discharged through the exhaust pipe contains a large amount of harmful gases and waste heat.

[0003] Through actual measurement and investigation, the blowing capacity of a 20kw gas stove with a blower is about 1500m 3 / hour. The 1500m 3 / hour exhaust gas contains a large amount of harmful gases and heat energy. These exhaust gases are discharged through a small pipeline with a cross section of about 60mm*150mm. The temperature measured at the exhaust pipe with a cross section of 60mm*150mm is about 180℃. However, it is difficult to recover heat using ordinary recovery devices because the cross section of the exhaust pipe is too small, the temperature is concentrated, and the temperature is high at times and low at times, which is extremely unstable.

[0004] In the prior art, a gas stove waste heat recovery device and its use method (CN112484101A) are disclosed. The device includes two gas stove supports on the upper surface of the gas stove body. The inner side walls of the gas stove supports are uniformly provided with grooves. The inner side walls of the grooves are connected with annular pipe bodies. The first pipe body is connected vertically with the two annular pipe bodies. The two second pipe bodies are connected with the two annular pipe bodies at the bottom. The third pipe body is connected with the outer side wall of the annular pipe body at the lower left corner. The fourth pipe body is connected with the outer side wall of the annular pipe body at the lower right corner. The present application can recover waste heat from open flames through the arrangement of the annular pipe body, the first pipe body, and the fourth pipe body. The first water tank and the shell can be used to recover waste heat from the heat in the steam.

[0005] The prior art mainly improves the structure of the gas stove to utilize waste heat from the gas stove. There is a lack of devices that can recover waste heat from the gas stove without modifying the structure of the existing gas stove. SUMMARY

[0006] The present application aims to solve the problems of the prior art, and provides a waste heat recovery device and method for a gas stove exhaust pipe, which directly connects with the gas stove exhaust pipe without improving the structure of the gas stove, and solves the problem of waste heat utilization of the gas stove exhaust pipe.

[0007] The present application provides a waste heat recovery device for a gas stove exhaust pipe, which comprises a shell, the shell is a rectangular box, a heat exchange module is arranged in the shell, the heat exchange module comprises an auxiliary cooling module and a cooling module, an air inlet and an air outlet are formed on the front and rear sides of the shell, and an air inlet pipe and an air outlet pipe are fixedly connected at the air inlet and the air outlet, respectively.

[0008] An auxiliary agent is introduced into the auxiliary cooling module, the auxiliary agent has a heat-sensitive activity and is used to accelerate the uniform distribution of heat of the exhaust gas in the shell in the direction perpendicular to the movement direction of the exhaust gas.

[0009] A cooling liquid is introduced into the cooling module, which is used to cool the high-temperature exhaust gas in the shell.

[0010] The auxiliary agent is a heat-sensitive agent.

[0011] The cooling liquid is water, and the cooling module is made of food-grade stainless steel.

[0012] Further, the auxiliary cooling module is composed of an auxiliary cooling pipe, the auxiliary cooling pipe is sealed at both ends, the auxiliary agent is filled in the auxiliary cooling pipe, the auxiliary cooling pipe is connected with a straight pipe section I through a U-shaped bend I, and a plurality of straight pipe sections I and U-shaped bends I are sequentially connected in front of and behind each other to form a serpentine coil.

[0013] Further, the cooling module comprises an inlet header pipe, an outlet header pipe, an inlet pipe, an outlet pipe and a plurality of heat exchange pipes, both ends of the inlet header pipe and the outlet header pipe are closed, the inlet pipe and the outlet pipe are connected to the middle of the inlet header pipe and the outlet header pipe, respectively, the inlet pipe and the outlet pipe penetrate one side of the shell adjacent to the air outlet or the air inlet, one end of each of the plurality of heat exchange pipes is connected to the inlet header pipe, and the other end is connected to the outlet header pipe, the heat exchange pipe is connected with a straight pipe section II through a U-shaped bend II, and a plurality of straight pipe sections II and U-shaped bends II are sequentially connected in front of and behind each other to form a serpentine coil.

[0014] Further, the outer periphery profile of the cross section of the auxiliary cooling pipe and the plurality of heat exchange pipes is generally rectangular, the auxiliary cooling pipe and the heat exchange pipe are placed perpendicular to the movement direction of the exhaust gas, end covers are fixedly arranged at both ends of the auxiliary cooling pipe and the plurality of heat exchange pipes, and the end covers penetrate the auxiliary cooling pipe and the heat exchange pipe.

[0015] The auxiliary cooling module and the cooling module are alternately arranged in layers along the direction perpendicular to the exhaust gas movement direction.

[0016] Further, the inlet pipe is close to the air outlet pipe, and the outlet pipe is close to the air inlet pipe.

[0017] Further, a plurality of uniform temperature plates are arranged at equal intervals through the auxiliary cooling pipe and the heat exchange pipe between the two end covers.

[0018] Further, the heat exchange module is composed of two auxiliary cooling modules and one cooling module, and the auxiliary cooling modules are arranged on the two sides of the cooling module respectively.

[0019] Further, the U-shaped bend I is connected with the straight pipe section I after being inclined, and the inclined direction of the U-shaped bend I connected with the two ends of the straight pipe section I is opposite.

[0020] Further, the cooling module is composed of two heat exchange pipes, and the two ends of each heat exchange pipe are located on the same side of the heat exchange module respectively.

[0021] Further, the U-shaped bend II is arranged to be inclined close to the inlet manifold, and the U-shaped bend II is arranged to be perpendicular to the exhaust gas movement direction away from the inlet manifold.

[0022] Further, the cross-sectional area of the air inlet pipe is 60% of the cross-sectional area of the air outlet pipe.

[0023] Further, a grid plate is arranged between the air inlet and the air inlet pipe and between the air outlet and the air outlet pipe respectively.

[0024] The beneficial effects of the present application are as follows:

[0025] (1) The exhaust gas enters the heat exchange module through the air inlet, and the heat of the exhaust gas close to the air inlet is focused. In the direction perpendicular to the exhaust gas movement direction, the heat distribution is uneven. In order to realize the efficient utilization of the waste heat on the exhaust pipe of the gas stove, a heat exchange module with multiple circuits is designed, mainly including an auxiliary cooling module and a cooling module. The auxiliary cooling module is provided with a heat-sensitive additive. At room temperature, the additive can maintain good stability. After the high-temperature exhaust gas is introduced, the additive has certain activity, realizes the guidance of heat to the direction perpendicular to the movement direction, improves the uniformity of heat distribution in the device, and realizes the heat transfer through the design of multiple cooling circuits. The high-temperature heat source with a small cross section is transferred layer by layer, and then the heat energy is utilized to gradually heat the water passing through another channel of the pipe. After the step-by-step heating, the water temperature can reach nearly 50 DEG C.

[0026] (2) Since the cooling module is made of food-grade stainless steel material, it can be directly recycled and used for food processing. As long as the gas stove ignites, there will be a continuous supply of hot water. This not only utilizes the waste heat discharged by the gas stove, but also saves the cost of natural gas for heating water, reduces the temperature of the exhaust pipe, and provides an additional guarantee for the safe operation of the gas stove (many exhaust pipes catch fire due to high temperature and excessive oil stains), reduces the urban heat island effect, and reduces the urban environmental pressure. It is the best product option for energy saving and consumption reduction. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, a brief introduction will be given below to the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and those skilled in the art can obtain other drawings according to the provided drawings without creative labor.

[0028] Figure 1 An external structure schematic diagram of a waste heat recovery device for a gas stove exhaust pipe provided by the embodiment of the present application.

[0029] Figure 2 An internal structure schematic diagram of a waste heat recovery device for a gas stove exhaust pipe provided by the embodiment of the present application.

[0030] Figure 3 A structure schematic diagram of a heat exchange module provided by the embodiment of the present application.

[0031] Figure 4 A structure schematic diagram of an auxiliary cooling pipe and a cooling pipe of a heat exchange module provided by the embodiment of the present application.

[0032] Figure 5 A connection schematic diagram of U-shaped bends I and II near the inlet header pipe side of a heat exchange module provided by the embodiment of the present application.

[0033] In the figure: 1, shell; 2, heat exchange module; 21, auxiliary cooling module; 211, auxiliary cooling pipe; 2111, U-shaped bend I; 2112, straight pipe section I; 22, cooling module; 221, inlet header pipe; 222, outlet header pipe; 223, inlet pipe; 224, outlet pipe; 225, heat exchange pipe; 2251, U-shaped bend II; 2252, straight pipe section II; 23, end cover; 24, uniform temperature plate; 3, air inlet pipe; 4, air outlet pipe; 5, grid plate. EMBODIMENT

[0034] All features disclosed in this specification, or all steps of any methods or processes disclosed in this specification, can be combined in any manner, except where mutually exclusive.

[0035] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features for a similar purpose, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0036] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples.

[0037] This application provides a waste heat recovery device for the exhaust pipe of a gas stove, such as... Figure 1 and Figure 2 As shown, the device includes a housing 1, which is a rectangular box. A heat exchange module 2 is installed inside the housing 1. The heat exchange module 2 includes an auxiliary cooling module 21 and a cooling module 22. An air inlet and an air outlet are provided on the front and rear sides of the housing 1. An air inlet pipe 3 and an air outlet pipe 4 are fixedly connected to the air inlet and the air outlet, respectively.

[0038] The inlet pipe 3 and outlet pipe 4 of the waste heat recovery device are connected to the exhaust pipe of the gas stove. The cross-sectional shape of the inlet pipe 3 and outlet pipe 4 is consistent with the cross-sectional shape of the exhaust pipe, which is generally circular or rectangular. Waste gas enters the housing 1 through the inlet pipe 3. A heat exchange module 2 is installed inside the housing 1. Waste heat is recovered and reused in the heat exchange module 2. This device does not require any modification to the existing gas stove structure and can be directly connected to the exhaust pipe, making it convenient to install and use.

[0039] An additive with thermosensitive activity is introduced into the auxiliary cooling module 21 to accelerate the uniform distribution of heat of the exhaust gas in the shell 1 in a direction perpendicular to its movement.

[0040] In this embodiment, a heat-sensitive additive is introduced into the auxiliary cooling module 21. This additive can maintain good stability at room temperature. After high-temperature waste gas is introduced, the additive becomes active, which guides heat to a direction perpendicular to its movement and improves the uniformity of heat distribution inside the device.

[0041] Coolant is introduced into the cooling module 22 to cool the high-temperature exhaust gas inside the housing 1.

[0042] In this embodiment, the exhaust gas transfers heat through the cooling module 22. The exhaust gas is in direct contact with the cooling module, which heats the coolant in the cooling module, thus realizing the reuse of high-temperature heat in the exhaust gas.

[0043] In order to achieve the lateral guidance of exhaust gas heat within the shell, that is, to achieve heat guidance perpendicular to the direction of exhaust gas movement, the additive used is a heat sensitizer. It can maintain good stability at room temperature (below 34℃), but when heated to a certain temperature, the activity of the substance is greatly enhanced through heat absorption, thereby achieving the lateral guidance of heat.

[0044] The coolant is water, and the cooling module is made of food-grade stainless steel.

[0045] In this embodiment, the coolant is water. Since the cooling module is made of food-grade stainless steel, it can be directly recycled and reused for food processing. As long as the gas stove is ignited, a continuous supply of hot water is generated. This not only utilizes the waste heat discharged from the gas stove, saving on natural gas costs for heating water, but also reduces the temperature of the exhaust pipe, providing an extra layer of assurance for the safe operation of the gas stove (many exhaust pipes catch fire due to high temperatures and excessive grease). It also reduces the urban heat island effect and lowers the pressure on urban environmental protection, making it the optimal product option for achieving energy conservation and emission reduction goals.

[0046] The following is in conjunction with the appendix Figures 3-5 The modules of a waste heat recovery device for a gas stove exhaust pipe are further described below:

[0047] The auxiliary cooling module 21 is composed of an auxiliary cooling pipe 211. The two ends of the auxiliary cooling pipe 211 are sealed. The auxiliary cooling pipe 211 is filled with an additive. The auxiliary cooling pipe 211 is connected to the straight pipe section I2112 by a U-shaped elbow I2111. Multiple straight pipe sections I2112 and U-shaped elbows I2111 are connected one after the other to form a serpentine coil.

[0048] Before the device is installed and used, an additive will be filled into the auxiliary cooling pipe 211 of the auxiliary cooling module 21. After the additive is filled, both ends of the auxiliary cooling pipe 211 will be sealed.

[0049] The cooling module 22 consists of an inlet manifold 221, an outlet manifold 222, an inlet pipe 223, an outlet pipe 224, and several heat exchange tubes 225. The inlet manifold 221 and the outlet manifold 222 are closed at both ends. The inlet pipe 223 and the outlet pipe 224 are respectively connected to the middle of the inlet manifold 221 and the outlet manifold 222. The inlet pipe 223 and the outlet pipe 224 penetrate one side of the shell 1 adjacent to the air outlet or air inlet. One end of the several heat exchange tubes 225 is connected to the inlet manifold 221, and the other end is connected to the outlet manifold 222. The heat exchange tubes 225 are connected to the straight pipe section II2252 by U-shaped elbows II2251, and the multiple straight pipe sections II2252 and U-shaped elbows II2251 are connected one after the other to form a serpentine coil.

[0050] The outer periphery of the cross-section formed by the auxiliary cooling pipe 211 and several heat exchange pipes 225 is roughly rectangular. The auxiliary cooling pipe 211 and the heat exchange pipes 225 are placed perpendicular to the direction of exhaust gas movement. In order to fix the auxiliary cooling pipe 211 and the heat exchange pipes 225, end caps 23 are fixedly installed at both ends of the auxiliary cooling pipe 211 and the several heat exchange pipes 225. The end caps 23 penetrate the auxiliary cooling pipe 211 and the heat exchange pipes 225.

[0051] The heat exchange module includes an auxiliary cooling circuit and a heat exchange circuit consisting of multiple heat exchange tubes. The design of multiple circuits enables heat transfer, transferring the high-temperature heat source with a very small cross-section through layers. Then, using this heat energy, the water passing through another channel of the tube is gradually heated in a gradient.

[0052] In order to achieve a uniform distribution of exhaust heat within the casing, rather than being mainly concentrated in the direction of exhaust gas movement, in this embodiment, the auxiliary cooling module 21 and the cooling module 22 are arranged alternately in layers along the direction perpendicular to the exhaust gas movement.

[0053] like Figure 3 As shown, the inlet pipe 223 is close to the outlet pipe 4, and the outlet pipe 224 is close to the inlet pipe 3.

[0054] To further achieve a uniform distribution of heat within the shell (1), such as Figure 3 As shown, several heat exchange plates 24 are arranged at equal intervals between the two end caps 23, passing through the auxiliary cooling pipe 211 and the heat exchange pipe 225.

[0055] Depending on the size of the waste heat recovery device, multiple auxiliary cooling modules and alternating layered cooling modules can be designed. Since this device is applied to the exhaust pipe of a gas stove, with a pipe cross-section of approximately 60mm*150mm, designing heat exchange modules that are too large for such a small pipe would increase waste heat utilization costs. Conversely, designing the device too small would result in insufficient utilization of waste heat in the exhaust gas. Therefore, the appropriate design should be based on the actual needs of the exhaust gas pipe, such as… Figure 4 As shown, in this embodiment, the heat exchange module consists of two auxiliary cooling modules 21 and one cooling module 22, with the auxiliary cooling modules respectively disposed on both sides of the cooling module.

[0056] like Figure 3 , 4 As shown, the auxiliary cooling module 21 consists of an auxiliary cooling pipe 211. In the auxiliary cooling pipe 211, the U-shaped bend I2111 is tilted and connected to the straight pipe section I2112. The tilting direction of the U-shaped bend I2111 connected to both ends of the same straight pipe section I2112 is opposite.

[0057] Depending on the size of the gas stove exhaust pipe, in this embodiment, the cooling module 22 consists of two heat exchange tubes 225, with both ends of each heat exchange tube 225 located on the same side of the heat exchange module 2.

[0058] like Figure 4 As shown, on the side near the inlet manifold 221, the U-shaped elbow II2251 is installed at an angle, as... Figure 3 As shown, on the side away from the inlet manifold 221, the U-shaped elbow II2251 is set perpendicular to the direction of exhaust gas movement.

[0059] To improve heat exchange efficiency, the cross-sectional area of ​​the air inlet duct 3 is 60% of the cross-sectional area of ​​the air outlet duct 4.

[0060] To protect the heat exchange module 2 inside the casing 1, and to increase the flow of exhaust gas, such as Figure 1 , Figure 2 As shown, grid plates 5 are respectively installed between the air inlet and the air inlet pipe 3, and between the air outlet and the air outlet pipe 4.

[0061] The grid plate 5 is set between the air inlet and the air inlet pipe 3, and between the air outlet and the air outlet pipe 4, which facilitates installation and replacement.

[0062] The above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A waste heat recovery device for a gas stove exhaust pipe, characterized in that, Includes a housing (1), which is a rectangular box. A heat exchange module (2) is provided inside the housing (1). The heat exchange module (2) includes an auxiliary cooling module (21) and a cooling module (22). An air inlet and an air outlet are provided on the front and rear sides of the housing (1). An air inlet pipe (3) and an air outlet pipe (4) are fixedly connected to the air inlet and the air outlet, respectively. The auxiliary cooling module (21) is composed of an auxiliary cooling pipe (211), which is sealed at both ends. An additive is filled inside the auxiliary cooling pipe (211). The auxiliary cooling pipe (211) is connected to a straight pipe section (2112) by a U-shaped elbow I (2111). Multiple straight pipe sections I (2112) and U-shaped elbows I (2111) are connected one after the other to form a serpentine coil. An additive is introduced into the auxiliary cooling module (21). The additive has thermosensitive activity and is used to accelerate the uniform distribution of heat of the exhaust gas in the shell (1) in a direction perpendicular to its movement. The additive is a thermosensitive agent. The cooling module (22) consists of an inlet manifold (221), an outlet manifold (222), an inlet pipe (223), an outlet pipe (224), and several heat exchange tubes (225). The inlet manifold (221) and the outlet manifold (222) are closed at both ends. The inlet pipe (223) and the outlet pipe (224) are respectively connected to the middle portions of the inlet manifold (221) and the outlet pipe (222). The inlet pipe (223) and the outlet pipe (224) penetrate the casing (1) adjacent to the air outlet or air inlet. On one side, one end of several heat exchange tubes (225) is connected to the inlet manifold (221), and the other end is connected to the outlet manifold (222). The heat exchange tubes (225) are connected to straight pipe sections (2252) by U-shaped elbows II (2251), and multiple straight pipe sections II (2252) and U-shaped elbows II (2251) are connected one after the other to form a serpentine coil. Coolant is introduced into the cooling module (22) to cool the high-temperature exhaust gas in the shell (1). The coolant is water, and the cooling module (22) is made of food-grade stainless steel. The outer periphery of the cross-section formed by the auxiliary cooling pipe (211) and the heat exchange pipes (225) is generally rectangular. The auxiliary cooling pipe (211) and the heat exchange pipes (225) are placed perpendicular to the direction of exhaust gas movement. End caps (23) are fixedly provided at both ends of the auxiliary cooling pipe (211) and the heat exchange pipes (225). The end caps (23) penetrate the auxiliary cooling pipe (211) and the heat exchange pipes (225). Along the direction perpendicular to the exhaust gas movement, the auxiliary cooling module (21) and the cooling module (22) are arranged alternately in layers.

2. The waste heat recovery device for a gas stove exhaust pipe according to claim 1, characterized in that, The heat exchange module (2) consists of two auxiliary cooling modules (21) and one cooling module (22), with the auxiliary cooling modules (21) respectively located on both sides of the cooling module (22).

3. A waste heat recovery device for a gas stove exhaust pipe according to claim 1, characterized in that, The U-shaped bend I (2111) is tilted and connected to the straight pipe section I (2112), and the tilting direction of the U-shaped bend I (2111) connected to both ends of the same straight pipe section I (2112) is opposite.

4. A waste heat recovery device for a gas stove exhaust pipe according to claim 1, characterized in that, The cooling module (22) consists of two heat exchange tubes (225), with both ends of each heat exchange tube (225) located on the same side of the heat exchange module (2).

5. A waste heat recovery device for a gas stove exhaust pipe according to claim 1, characterized in that, On the side near the inlet manifold (221), the U-shaped elbow II (2251) is inclined, and on the side away from the inlet manifold (221), the U-shaped elbow II (2251) is perpendicular to the direction of exhaust gas movement.

6. A waste heat recovery device for a gas stove exhaust pipe according to claim 1, characterized in that, The cross-sectional area of ​​the air inlet pipe (3) is 60% of the cross-sectional area of ​​the air outlet pipe (4).

7. A waste heat recovery device for a gas stove exhaust pipe according to claim 1, characterized in that, A grid plate (5) is provided between the air inlet and the air inlet pipe (3) and between the air outlet and the air outlet pipe (4).

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