Waste heat recovery device and water heater

Abstract

The utility model discloses a waste heat recovery device and a water heater, and relates to the technical field of water heaters, the waste heat recovery device comprises a shell, a first heat exchanger and a second heat exchanger, and the shell is provided with a flue; the first heat exchanger and the second heat exchanger are arranged in the flue and arranged side by side in the extending direction of the flue, the first heat exchanger is provided with a first heat exchange channel used for exchanging heat with the flue, and the second heat exchanger is provided with a second heat exchange channel used for exchanging heat with the flue. The first heat exchanger and the second heat exchanger are arranged side by side in the extending direction of the flue. According to the technical scheme, the first heat exchanger and the second heat exchanger which are independent are arranged, so that the temperature difference between the first heat exchange medium and the second heat exchange medium can be better controlled, and the recovery rate of the waste heat recovery device to flue gas waste heat can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of water heaters, in particular to a waste heat recovery device and a water heater. Background Art

[0002] Gas water heaters are equipped with waste heat recovery devices to recover waste heat from combustion flue gases, reduce energy waste, and improve overall thermal efficiency. However, existing devices suffer from uneven flue gas temperature distribution, insufficient heat exchange, and low waste heat recovery rates. Utility Model Content

[0003] The main purpose of the utility model is to provide a waste heat recovery device and a water heater, aiming to improve the recovery rate of the waste heat recovery device for flue gas waste heat.

[0004] To achieve the above-mentioned purpose, the waste heat recovery device proposed in the present invention comprises:

[0005] a shell body provided with a flue;

[0006] A first heat exchanger is provided in the flue, wherein the first heat exchanger is provided with a first heat exchange channel for exchanging heat with the flue; and

[0007] The second heat exchanger is provided in the flue. The second heat exchanger is provided with a second heat exchange channel for exchanging heat with the flue. The first heat exchanger and the second heat exchanger are arranged side by side along the extension direction of the flue.

[0008] In one embodiment, the housing has a cavity, a smoke inlet and a smoke exhaust port communicated with the cavity;

[0009] The waste heat recovery device also includes a guide plate arranged on the cavity, which divides the cavity into a first heat exchange cavity and a second heat exchange cavity. The smoke inlet, the first heat exchange cavity, the second heat exchange cavity and the smoke exhaust port are connected in sequence to form the flue. The first heat exchanger is arranged in the first heat exchange cavity, and the second heat exchanger is arranged in the second heat exchange cavity.

[0010] In one embodiment, the shell includes a shell body and two end plates, the shell body is cylindrical, the shell body and the two end plates enclose the cavity, the smoke exhaust port is provided on the top surface of the shell body, and the smoke inlet is provided on the side of the shell body;

[0011] The guide plate includes a plate body, a connecting portion and a bending portion provided on the plate body, the connecting portion is connected to the shell body, the plate body is tilted downward from the connection between it and the connecting portion, the bending portion is arranged at an angle to the plate body, and the angle between the bending portion and the plate body is arranged toward the first heat exchange cavity.

[0012] In one embodiment, the first heat exchanger includes a plurality of first tubes, wherein the first heat exchange channels are formed in the tubes of the first tubes;

[0013] The plurality of first tubes are divided into at least two groups of heat exchange tube groups along a first direction. The first tubes in the heat exchange tube groups are arranged in rows and at intervals along a second direction. The first direction and the second direction intersect, and the first tubes of adjacent heat exchange tube groups are staggered in the first direction.

[0014] In one embodiment, the inner wall of the first tube is provided with a groove; and / or the outer wall of the first tube is provided with a groove.

[0015] In one embodiment, the groove is an annular groove, and the groove extends along the circumference of the first tube body.

[0016] In one embodiment, the first pipe body includes a plurality of first pipe segments and a plurality of connecting pipe segments, the plurality of first pipe segments are arranged at intervals along the first direction, and the plurality of first pipe segments are sequentially connected through the connecting pipe segments.

[0017] In one embodiment, the waste heat recovery device includes two first adapters, which are covered on the end plate and enclosed with the end plate to form two first connecting cavities. The first adapter is provided with a first adapter interface connected to the first connecting cavity; the two ends of the first tube body are respectively connected to the end plate, and the two ends of the first heat exchange channel are respectively connected to the two first connecting cavities.

[0018] In one embodiment, the waste heat recovery device also includes two second adapters, which are covered on the end plate and enclosed with the end plate to form two second connecting cavities. The second adapter is provided with a second adapter interface connected to the second connecting cavity; the second heat exchanger includes a plurality of second tube bodies, and the second heat exchange channel is formed in the second tube body, and the two ends of the second heat exchange channel are respectively connected to the two second connecting cavities.

[0019] The utility model also provides a water heater, which includes:

[0020] A combustion chamber provided with a smoke outlet;

[0021] a main heat exchanger, disposed in the combustion chamber; and

[0022] In the waste heat recovery device described in any of the aforementioned embodiments, the smoke inlet of the flue is connected to the smoke outlet, the water outlet of the first heat exchanger is connected to the water inlet of the main heat exchanger, and both ends of the second heat exchange channel are respectively connected to a flow path system.

[0023] The technical solution of the present invention can better control the temperature difference between the first heat exchange medium and the second heat exchange medium by setting up independent first heat exchangers and second heat exchangers, thereby improving the recovery rate of flue gas waste heat by the waste heat recovery device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0025] Figure 1 This is a structural diagram of an embodiment of a waste heat recovery device provided by the present utility model;

[0026] Figure 2 for Figure 1 A side view of

[0027] Figure 3 for Figure 1 Another side view;

[0028] Figure 4 for Figure 1 A cross-sectional view after hiding the first heat exchanger and the second heat exchanger;

[0029] Figure 5 A schematic structural diagram of another embodiment of the waste heat recovery device provided by the present utility model;

[0030] Figure 6 This is a structural diagram of an embodiment of the first tube body;

[0031] Figure 7 This is a structural diagram of an embodiment of a staggered arrangement of the first tube body.

[0032] Description of Figure Numbers:

[0033] 10. Waste heat recovery device;

[0034] 100, shell; 101, smoke inlet; 102, smoke exhaust port; 103, first heat exchange chamber; 104, second heat exchange chamber; 110, shell body; 120, end plate;

[0035] 200, first heat exchanger; 210, first pipe body; 211, first pipe section; 212, connecting pipe section; 220, heat exchange group;

[0036] 300, second heat exchanger; 310, second tube;

[0037] 400, guide plate; 410, plate body; 420, connecting portion; 430, bending portion;

[0038] 500, first adapter; 510, first communicating cavity; 520, first adapter;

[0039] 600, second adapter; 610, second connecting cavity; 620, second adapter port.

[0040] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention.

[0042] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0043] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0044] The present invention proposes a waste heat recovery device 10, which is applied to a gas heating device, such as a gas water heater or a gas wall-mounted boiler, etc., and is intended to improve the recovery rate of the waste heat of the flue gas by the waste heat recovery device 10. The waste heat recovery device 10 can be sold separately or in combination with the gas heating device. Figures 1 to 7 In the figure, the solid arrows indicate spaces, slots or holes. For the convenience of description, the following is an example of applying the waste heat recovery device 10 to a gas water heater.

[0045] Among them, a gas water heater usually includes a water heater body, which usually includes a shell 100, a combustion chamber, a burner, a main heat exchanger, an ignition device, an electrical control box, a control valve assembly, an expansion tank, etc. The burner, main heat exchanger, ignition device, electrical control box, control valve assembly and expansion tank are usually arranged in the shell 100. The burner and main heat exchanger are arranged in the combustion chamber. The burner is one of the core components of the gas water heater, responsible for mixing gas with air and burning it to generate heat. The main heat exchanger is used to transfer the heat generated by the burner to the water flowing through it; the ignition device is used to ignite the gas in the burner, which can be spark ignition or thermocouple ignition; the electrical control box is used to manage and control various electronic and electrical functions. The electrical control box usually contains multiple circuit boards, sensor interfaces, control software and other electronic components, and is responsible for coordinating various operations of the gas water heater.

[0046] See also Figures 1 to 7 In the present invention, the waste heat recovery device 10 includes a shell 100, in which a flue, a smoke inlet 101 and a smoke outlet 102 connected to the flue are provided. The smoke inlet 101 is used to communicate with the smoke outlet of the combustion chamber, so as to introduce the flue gas in the combustion chamber after heat exchange in the main heat exchanger into the flue. Secondly, the shell 100 serves as the outer shell of the waste heat recovery device 10 and plays a role in protecting the internal components. In some embodiments, the shell 100 has a certain thermal insulation performance, which can reduce heat loss, maintain the temperature of hot water in the heat exchanger, and improve energy utilization efficiency. The thermal insulation setting of the shell 100 can reduce energy waste, thereby further improving the recovery efficiency of the airflow.

[0047] In this embodiment, in order to improve the recovery rate of flue gas waste heat by the waste heat recovery device 10, the waste heat recovery device 10 also includes a first heat exchanger 200 and a second heat exchanger 300 arranged in the flue, the first heat exchanger 200 is provided with a first heat exchange channel for exchanging heat with the flue, and the second heat exchanger 300 is provided with a second heat exchange channel for exchanging heat with the flue, and the first heat exchanger 200 and the second heat exchanger 300 are arranged side by side along the extension direction of the flue.

[0048] The first heat exchange channel of the first heat exchanger 200 is used for heat exchange between the first heat exchange medium and the flue gas, and the second heat exchanger 300 is used for heat exchange between the second heat exchange medium and the flue gas. The second heat exchange medium and the first heat exchange medium can be water or air, etc. In this embodiment, the waste heat recovery device 10 is applied to a gas water heater. The first heat exchange medium and the second heat exchange medium can both be water, or one of the first heat exchange medium and the second heat exchange medium can be water and the other can be air, etc., and the air is used to supply the burner of the gas water heater. For example, in a preferred embodiment, the first heat exchange medium and the second heat exchange medium can both be water, and the temperature of the first heat exchange medium entering the first heat exchange channel is higher than the temperature of the second heat exchange medium entering the second heat exchange channel.

[0049] Regarding the side-by-side arrangement of the first heat exchanger 200 and the second heat exchanger 300 along the extension direction of the flue, it can be understood that, in the process from the smoke inlet 101 to the smoke outlet, the flue gas first exchanges heat with the first heat exchanger 200, and then exchanges heat with the second heat exchanger 300. Since the temperature of the first heat exchange medium entering the first heat exchange channel is higher than the temperature of the second heat exchange medium entering the second heat exchange channel, the high-temperature flue gas first exchanges heat with the first heat exchange medium with a higher temperature, and then exchanges heat with the second heat exchange medium with a relatively low temperature, which can better utilize the waste heat of the flue gas. Secondly, by independently arranging the first heat exchanger 200 and the second heat exchanger 300, the temperature difference between the first heat exchange medium and the second heat exchange medium can be better controlled, thereby improving the recovery rate of the waste heat of the flue gas by the waste heat recovery device 10.

[0050] The technical solution of the present invention can better control the temperature difference between the first heat exchange medium and the second heat exchange medium by setting up an independent first heat exchanger 200 and the second heat exchanger 300, thereby improving the recovery rate of the waste heat recovery device 10 for the flue gas waste heat.

[0051] In an exemplary embodiment, the shell 100 has a cavity, a smoke inlet 101 and a smoke exhaust port 102 connected to the cavity; the waste heat recovery device 10 also includes a guide plate 400 arranged in the cavity, and the guide plate 400 divides the cavity into a first heat exchange cavity 103 and a second heat exchange cavity 104. The smoke inlet 101, the first heat exchange cavity 103, the second heat exchange cavity 104 and the smoke exhaust port 102 are connected in sequence to form the flue, the first heat exchanger 200 is arranged in the first heat exchange cavity 103, and the second heat exchanger 300 is arranged in the second heat exchange cavity 104.

[0052] In this way, the guide plate 400 is provided in this embodiment, which can change the flow direction and velocity distribution of the airflow inside the heat exchanger, increase the contact time and area between the fluid and the heat exchange surface, strengthen the heat transfer, and improve the heat recovery efficiency of the waste heat recovery device 10. Secondly, by guiding the flow of air through the guide plate 400, it can be evenly distributed in the flue, avoiding airflow short circuits and local dead zones, thereby improving the heat exchange effect. Furthermore, the provision of the guide plate 400 can optimize the flow state of the fluid, reduce the eddy currents and turbulence of the fluid, reduce the resistance of the fluid, and increase the stability and reliability of the system. In addition, by providing the guide plate 400, the temperature unevenness of the fluid in the flue can also be reduced, making the temperature distribution of the fluid more uniform during the heat exchange process.

[0053] Based on the previous embodiment, the shell 100 includes a shell body 110 and two end plates 120, the shell body 110 is cylindrical, the shell body 110 and the two end plates 120 enclose the cavity, the smoke exhaust port 102 is provided on the top surface of the shell body 110, and the smoke inlet 101 is provided on the side of the shell body 110; the guide plate 400 includes a plate body 410, a connecting portion 420 and a bending portion 430 provided on the plate body 410, the connecting portion 420 is connected to the shell body 110, the plate body 410 is tilted downward from the connection between it and the connecting portion 420, the bending portion 430 is arranged at an angle to the plate body 410, and the angle between the bending portion 430 and the plate body 410 is arranged toward the first heat exchange cavity 103.

[0054] The plate body 410 is tilted downward from the connection between it and the connecting portion 420, and the bending portion 430 is arranged at an angle to the plate body 410, and the angle between the bending portion 430 and the plate body 410 is arranged toward the smoke inlet 101, wherein the bending portion 430 and the plate body 410 are both thin plate-like components, generally sheet metal parts, and the bending portion 430 and the plate body 410 can be bent or folded.

[0055] In this embodiment, the bending portion 430 is bent toward the side where the waste heat exchanger is located. The bending portion 430 can change the flow path of the fluid, increase the contact time and contact area between the fluid and the heat exchange surface, and thus improve the heat transfer efficiency. Secondly, the bending portion 430 is bent toward the side where the waste heat exchanger is located, which can cause turbulence in the fluid. The fluid in the turbulent state is more fully mixed, the heat exchange efficiency is higher, and the thermal resistance of the boundary layer can be effectively reduced. The bending portion is bent toward the side where the waste heat exchanger is located to avoid the formation of a short-circuit path when the fluid flows through the waste heat exchanger, so that the airflow can pass through the entire waste heat exchanger evenly, thereby achieving a more uniform temperature distribution and higher heat exchange performance. In addition, the guide plate 400 is arranged in this way to improve its rigidity and strength, making it more stable and less prone to deformation under high flow rate or high pressure conditions.

[0056] Furthermore, the angle between the plate body 410 and the bent portion 430 is not less than 90° and not greater than 110°. The angle between the plate body 410 and the bent portion 430 refers to the angle on the side facing the first heat exchange chamber 103. The angle between the plate body 410 and the bent portion 430 includes, but is not limited to, 90°, 91°, 92°, 93°, 94°, 95°, 96°, 97°, 98°, 99°, 100°, 101°, 102°, 103°, 104°, 105°, 106°, 107°, 108°, 109°, or 110°.

[0057] In one embodiment, see Figure 4 The middle part of the plate body 410 is raised toward one side of the first heat exchange chamber 103. This arrangement makes the distance between the plate body 410 and the waste heat exchanger unequal, which can further optimize the flow state of the fluid, increase the contact time and area between the fluid and the heat exchange surface, and further improve the recovery rate of the waste heat recovery device 10 for the waste heat of the flue gas.

[0058] In one embodiment, see Figure 7 The first heat exchanger 200 includes a plurality of first tubes 210, wherein the first heat exchange channels are formed inside the first tubes 210. The plurality of first tubes 210 are divided into at least two heat exchange tube groups along a first direction. The first tubes 210 in the heat exchange tube groups are arranged in rows and at intervals along a second direction. The first direction and the second direction intersect, and the first tubes 210 of adjacent heat exchange tube groups are staggered in the first direction.

[0059] In this embodiment, it can be understood that the plurality of first tubes 210 are arranged in an array, specifically a circular array, a square array, or an array of other shapes, etc. For example, a first heat exchange tube group and a second heat exchange tube group are distributed along a first direction, and a plurality of first tubes 210 are provided in the first heat exchange tube group and the second heat exchange tube group. The number of first tubes 210 in the first heat exchange tube group and the second heat exchange tube group can be one, two, three, four, five, six, or more.

[0060] In this embodiment, the first tubes 210 of adjacent heat exchange tube groups are staggered in the first direction, allowing for more even distribution of fluid as it passes through the heat exchange tube group, increasing the contact area between the fluid and the tubes, and thereby enhancing convective heat transfer. Furthermore, this arrangement reduces heat concentration within the heat exchanger, resulting in a more uniform temperature distribution.

[0061] In one embodiment, in order to improve the performance, an inner wall of the first tube body 210 is provided with a groove; and / or an outer wall of the first tube body 210 is provided with a groove.

[0062] In this embodiment, the grooves increase the contact area between the pipe wall and the fluid, thereby enhancing heat conduction. Furthermore, the grooves increase fluid agitation, improving the fluid's flow, enabling more uniform heat transfer and increasing heat exchange efficiency. Furthermore, by improving fluid flow and heat transfer, the grooves can reduce temperature differences within the pipe, increasing the stability of the heat exchange process.

[0063] Preferably, the groove is an annular groove extending along the circumference of the first tube body 210. In other embodiments, multiple grooves may be arranged at intervals along the circumference of the first tube body 210. Furthermore, the number of the grooves is multiple, and the grooves are arranged at intervals along the length of the first tube body 210.

[0064] It is worth mentioning that, in a preferred embodiment, in order to make the first tube body 210 have better structural strength, the groove provided on the inner wall of the first tube body 210 and the groove provided on the outer wall of the first tube body 210 are staggered.

[0065] See also Figure 6 In one embodiment, the first tube body 210 includes a plurality of first tube sections 211 and a plurality of connecting tube sections 212 . The plurality of first tube sections 211 are arranged at intervals along the first direction, and the plurality of first tube sections 211 are connected in sequence through the connecting tube sections 212 .

[0066] The connecting pipe section 212 is typically curved, with the first pipe section 211 having at least two sections and the connecting pipe section 212 having at least one section. In this embodiment, the water inlet and outlet of the first heat exchanger 200 can be located on the same side of the housing 100, thereby facilitating the layout of the gas water heater's water system. Thus, the configuration of the first pipe body 210 increases the length of the first heat exchange channel, correspondingly increasing the heat exchange surface area and thereby improving heat exchange efficiency. Furthermore, the configuration of the first pipe body 210 can effectively disrupt the laminar flow of the fluid, promote fluid mixing, reduce temperature distribution unevenness, and thereby improve heat exchange efficiency.

[0067] In one embodiment, the waste heat recovery device 10 includes two first adapters 500, which are covered on the end plate 120 and enclosed with the end plate 120 to form two first connecting cavities 510. The first adapter 500 is provided with a first adapter port 520 connected to the first connecting cavity 510; the two ends of the first tube body 210 are respectively connected to the end plate 120, and the two ends of the first heat exchange channel are respectively connected to the two first connecting cavities 510.

[0068] In this embodiment, the first adapter 500 can be a cover plate or a cover. When the first adapter 500 is set as a cover plate, a concave cavity needs to be constructed on the end plate 120, and the cover plate covers the concave cavity to form two first connecting cavities 510; when the first adapter 500 is set as a cover, a concave cavity can be constructed on the end plate 120, or a concave cavity can be not opened. Preferably, a concave cavity is set on the end plate 120, which not only improves the structural strength of the end plate 120, but also improves the sealing of the connection between the first adapter 500 and the end plate 120.

[0069] The ends of the first tube 210 are fixedly connected to the end plate 120 (the connection can be detachable or non-detachable), and the two ends of the first heat exchange channel are connected to the two first communication chambers 510. In this way, when the waste heat recovery device 10 is applied to the embodiment of the gas water heater, the fluid can be fully mixed before entering the main heat exchanger, thereby improving the uniformity of the water inlet.

[0070] It is understood that the two first adapters 500 can be two separate components or can be integrally formed. Preferably, the two first adapters 500 are two separate components. Furthermore, the two first connecting cavities 510 generally need to form independent cavities, that is, the two first connecting cavities 510 are connected via the first tube 210. Of course, in one embodiment, the two first adapters 500 are one first connecting member disposed on one end plate 120. In this case, the two first adapters 500 need to be two separate components.

[0071] In an exemplary embodiment, the two first adapters 500 are installed on the same end plate 120 , and the two first adapters 500 are independently disposed on the end plate 120 .

[0072] In another embodiment, the waste heat recovery device 10 also includes two second adapters 600, which are covered on the end plate 120 and enclosed with the end plate 120 to form two second connecting cavities 610. The second adapter 600 is provided with a second adapter port 620 connected to the second connecting cavity 610; the second heat exchanger 300 includes a plurality of second tube bodies 310, and the second heat exchange channel is formed in the second tube body 310, and the two ends of the second heat exchange channel are respectively connected to the two second connecting cavities 610.

[0073] In this embodiment, the second adapter 600 is the same as the previous embodiment. It can be a cover plate or a cover. When the second adapter 600 uses a cover plate, a concave cavity needs to be constructed on the end plate 120, and the cover plate covers the concave cavity to form two second connecting cavities 610. When the second adapter 600 is set as a cover, a concave cavity can be constructed on the end plate 120, or no concave cavity can be opened. Preferably, a concave cavity is set on the end plate 120, which not only improves the structural strength of the end plate 120, but also improves the sealing of the connection between the second adapter 600 and the end plate 120.

[0074] The ends of the second tube 310 are fixedly connected to the end plate 120 (either detachably or non-detachably), and the two ends of the second heat exchange channel are connected to the two second communication chambers 610. This can also improve the temperature uniformity of the second heat exchange medium when it flows out of the waste heat recovery device 10.

[0075] It is understood that the two second adapters 600 can be two separate components, or they can be integrally formed with the two first adapters 500. Preferably, the two second adapters 600 are two separate components. Furthermore, the two second connecting cavities 610 generally need to form independent cavities, that is, the two second connecting cavities 610 are connected via the second tube 310. Of course, in one embodiment, the two second adapters 600 are one second connecting member disposed on one end plate 120. In this case, the two second adapters 600 need to be two separate components.

[0076] The present invention also proposes a water heater, which includes a water heater body and a waste heat recovery device 10. The specific structure of the waste heat recovery device 10 refers to the above embodiment. Since the water heater adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0077] In one embodiment, the water heater includes a combustion chamber and a main heat exchanger, the combustion chamber is provided with a smoke outlet, and the main heat exchanger is arranged in the combustion chamber; the smoke inlet 101 of the flue of the waste heat recovery device 10 described in any of the aforementioned embodiments is connected to the smoke outlet, the water outlet end of the first heat exchanger 200 is connected to the water inlet end of the main heat exchanger, and the two ends of the second heat exchange channel are respectively connected to a flow path system.

[0078] Wherein, both ends of the second heat exchange channel are respectively connected to a flow path system, wherein the flow path system can be a water path system or a gas path system.

[0079] Working process of the waste heat recovery device 10: When the gas water heater is working, the gas and air are mixed and burned in the combustion chamber to produce high-temperature flue gas. These flue gases first pass through the main heat exchanger, where most of the heat is absorbed to heat water, and the remaining heat is further absorbed by the waste heat recovery device 10. The first heat exchanger 200 in the waste heat recovery device 10 transfers the heat in the flue gas to the cold water to achieve preheating, and then the flue gas finally passes through the second heat exchanger 300. In this way, the cold water entering the main heat exchanger has been preheated in the first heat exchanger 200, thereby improving the thermal efficiency of the entire gas water heater and reducing the heat discharged to the environment. In addition, in this embodiment,

[0080] Regarding the installation position of the waste heat recovery device 10, the waste heat recovery device 10 is usually installed on the top of the gas water heater. Of course, in some embodiments, it can be installed on the side or even outside the gas water heater, etc. The main thing is that the first heat exchange channel of the first heat exchanger 200 needs to be connected to the water system of the gas water heater.

[0081] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A waste heat recovery device, characterized in that: include: a shell body provided with a flue; a first heat exchanger, disposed in the flue, wherein the first heat exchanger is provided with a first heat exchange channel for exchanging heat with the flue; as well as The second heat exchanger is provided in the flue. The second heat exchanger is provided with a second heat exchange channel for exchanging heat with the flue. The first heat exchanger and the second heat exchanger are arranged side by side along the extension direction of the flue.

2. The waste heat recovery device according to claim 1, characterized in that: The housing comprises a cavity, a smoke inlet and a smoke outlet communicated with the cavity; The waste heat recovery device also includes a guide plate arranged on the cavity, which divides the cavity into a first heat exchange cavity and a second heat exchange cavity. The smoke inlet, the first heat exchange cavity, the second heat exchange cavity and the smoke exhaust port are connected in sequence to form the flue. The first heat exchanger is arranged in the first heat exchange cavity, and the second heat exchanger is arranged in the second heat exchange cavity.

3. The waste heat recovery device according to claim 2, characterized in that: The shell includes a shell body and two end plates, the shell body is cylindrical, the shell body and the two end plates enclose the cavity, the smoke exhaust port is provided on the top surface of the shell body, and the smoke inlet is provided on the side of the shell body; The guide plate includes a plate body, a connecting portion and a bending portion provided on the plate body, the connecting portion is connected to the shell body, the plate body is tilted downward from the connection between it and the connecting portion, the bending portion is arranged at an angle to the plate body, and the angle between the bending portion and the plate body is arranged toward the first heat exchange cavity.

4. The waste heat recovery device according to claim 3, characterized in that: The first heat exchanger includes a plurality of first tubes, wherein the first heat exchange channels are formed in the tubes of the first tubes; The plurality of first tubes are divided into at least two groups of heat exchange tube groups along a first direction. The first tubes in the heat exchange tube groups are arranged in rows and at intervals along a second direction. The first direction and the second direction intersect, and the first tubes of adjacent heat exchange tube groups are staggered in the first direction.

5. The waste heat recovery device according to claim 4, characterized in that: The inner wall of the first tube body is provided with a groove; and / or the outer wall of the first tube body is provided with a groove.

6. The waste heat recovery device according to claim 5, characterized in that: The groove is an annular groove and extends along the circumference of the first tube body.

7. The waste heat recovery device according to claim 4, characterized in that: The first pipe body includes a plurality of first pipe sections and a plurality of connecting pipe sections. The plurality of first pipe sections are arranged at intervals along the first direction, and the plurality of first pipe sections are sequentially connected through the connecting pipe sections.

8. The waste heat recovery device according to claim 4, characterized in that: The waste heat recovery device includes two first adapters, which are covered on the end plate and enclosed with the end plate to form two first connecting cavities. The first adapter is provided with a first adapter interface connected to the first connecting cavity; the two ends of the first tube body are respectively connected to the end plate, and the two ends of the first heat exchange channel are respectively connected to the two first connecting cavities.

9. The waste heat recovery device according to claim 3, characterized in that: The waste heat recovery device also includes two second adapters, which are covered on the end plate and enclosed with the end plate to form two second connecting cavities. The second adapter is provided with a second adapter interface connected to the second connecting cavity; the second heat exchanger includes multiple second tubes, and the second heat exchange channel is formed in the second tube. The two ends of the second heat exchange channel are respectively connected to the two second connecting cavities.

10. A water heater, characterized in that: include: A combustion chamber provided with a smoke outlet; a main heat exchanger, disposed in the combustion chamber; as well as According to the waste heat recovery device according to any one of claims 1 to 9, the smoke inlet of the flue is connected to the smoke outlet, the water outlet of the first heat exchanger is connected to the water inlet of the main heat exchanger, and both ends of the second heat exchange channel are respectively connected to a flow path system.

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