Water sleeve for heat pipe type low-temperature economizer

Abstract

The utility model belongs to the technical field of heat pipes, and particularly relates to a water sleeve for a heat pipe type low-temperature economizer. The water inlet sleeve, the first middle pipe, the second middle pipe and the water outlet sleeve in the water sleeve for the heat pipe type low-temperature economizer can be arranged on a plurality of heat pipes in a sleeving mode in a one-to-one correspondence mode, the water inlet sleeve and the first middle pipe form a water inlet section, and the water outlet sleeve and the second middle pipe form a water outlet section. The gap area between the water inlet section and the heat pipe and the gap area between the water outlet section and the heat pipe can be adjusted by increasing or reducing the number of the middle sleeves in the first middle pipe and the second middle pipe, so that the flow speed of cooling water is controlled, the use requirement is met, the water sleeve for the heat pipe type low-temperature economizer can adapt to heat pipes of different sizes, and the heat pipe type low-temperature economizer is suitable for various heat pipes of different sizes. And the application range is enlarged.

Description

Technical Field

[0001] This utility model belongs to the field of heat pipe technology, and specifically relates to a water jacket for a heat pipe type low-temperature economizer. Background Technology

[0002] A heat pipe low-temperature economizer is a device used to improve the cycle thermal efficiency of power plants. It recovers waste heat from flue gas to heat the boiler, thereby improving the utilization rate of fuel thermal energy, saving fuel, reducing production costs, and achieving rational optimization and utilization of resources.

[0003] The design flow velocity and design heat exchange area of ​​the water jacket of the heat pipe type low temperature economizer are determined by the size and arrangement of the water jacket. The water flow velocity and water-side heat exchange area in the water jacket need to be considered during the design to achieve reasonable optimization and utilization of resources. The water-side heat exchange area is determined by the length of the water jacket, and the water-side flow velocity is determined by the gap area between the inner diameter of the water jacket and the outer diameter of the heat pipe.

[0004] Currently, the common water jacket is installed on the heat pipe by connecting multiple jackets in series. The water flow is S-shaped under the guidance of multiple jackets. For different projects (the outer diameter of the heat pipe may be different in each project), different inner diameter jackets are required to determine the gap area between the inner diameter of the jacket and the outer diameter of the heat pipe so that the water flow velocity meets or approaches the set flow velocity.

[0005] However, the specifications of the existing water jackets are not the same. In order to make full use of the fuel heat energy, the fixed-size series pressure-resistant water jackets can only be adapted to a single size heat pipe and cannot be interchanged (if the jackets are replaced with different sizes, the water flow velocity will be affected, resulting in the heat exchange efficiency being affected), which limits the scope of use of water jackets. Utility Model Content

[0006] This utility model provides a water jacket for a heat pipe type low-temperature economizer, in order to solve the technical problem that in order to make full use of fuel thermal energy, the fixed-size series pressure-resistant water jacket can only be adapted to a single size heat pipe, which limits its application range.

[0007] To solve the above problems, this utility model is achieved through the following technical solution:

[0008] A water jacket for a heat pipe type low-temperature economizer includes an inlet jacket, an outlet jacket, and two sets of intermediate pipes;

[0009] The inlet sleeve is provided with an inlet A and two sets of outlets A, and the two sets of outlets A are respectively located near the two ends of the inlet sleeve.

[0010] The water outlet sleeve is provided with an inlet B and a drain B; the number of inlets B is equal to the number of drains A, and their positions correspond one-to-one.

[0011] The central pipe includes at least one central sleeve. The number of central sleeves in the two sets of central pipes is equal. The two sets of central pipes are a first central pipe and a second central pipe. The first central pipe and the second central pipe are both arranged between the inlet sleeve and the outlet sleeve. The outlet end of the first central pipe and the inlet end of the second central pipe are connected by a pipe fitting. The pipe fitting and the inlet A are respectively arranged at both ends of the central pipe. Both sets of outlets A are connected to the first central pipe, and both sets of inlets B are connected to the second central pipe.

[0012] The inlet sleeve, the first middle pipe, the second middle pipe, and the outlet sleeve are all fitted onto the heat pipe.

[0013] To better realize this utility model, further optimizations are made to the above structure, wherein the middle sleeve includes an inlet C and a outlet C;

[0014] The number of water inlets C is equal to the number of water outlets A, and their positions correspond one-to-one;

[0015] The number of drain outlets C is equal to the number of inlets B, and their positions correspond one-to-one;

[0016] When the central pipe includes a central sleeve, the two sets of drain outlets A and the two sets of inlet outlets C on the central sleeve of the first central pipe are connected; the two sets of inlet outlets B and the two sets of drain outlets C on the central sleeve of the second central pipe are connected; the set of drain outlets C on the central sleeve of the first central pipe away from the inlet A is connected to the set of inlet outlets C on the central sleeve of the second central pipe away from the inlet A; the set of drain outlets C on the central sleeve of the first central pipe close to the inlet A and the set of inlet outlets C on the central sleeve of the second central pipe close to the inlet A are sealed by a sealing member;

[0017] When the central pipe includes two or more central sleeves, the plurality of central sleeves in the first central pipe and the plurality of central sleeves in the second central pipe are arranged sequentially from the inlet end to the outlet end; and in the first central pipe, the two drain outlets C on the central sleeve near the inlet end are respectively connected to the two inlet outlets C on the central sleeve near the outlet end, and the two sets of drain outlets A are connected to the two sets of inlet outlets C on the central sleeve near the inlet sleeve in the first central pipe, and the set of drain outlets C on the central sleeve near the outlet end that is away from the inlet outlet A is the first central pipe. At the outlet end of the pipe, another set of drain ports C on the middle sleeve near the outlet end is sealed by a sealing element; in the second middle pipe, two drain ports C on the middle sleeve near the inlet end are respectively connected to two inlet ports C on the middle sleeve near the outlet end, and two sets of inlet ports B are connected to two sets of drain ports C on the middle sleeve near the outlet sleeve in the second middle pipe. The set of inlet ports C on the middle sleeve near the inlet end that is away from the inlet port A is the inlet end of the second middle pipe, and another set of drain ports C on the middle sleeve near the inlet end is sealed by a sealing element;

[0018] The outlet end of the first central pipe is connected to the inlet end of the second central pipe via a fitting.

[0019] To better realize this utility model, the above structure is further optimized. The sealing member is a cap-shaped structure, and the sealing member is threadedly connected to the water inlet C or the drain outlet C.

[0020] Compared with the prior art, this utility model has the following advantages:

[0021] The water jacket, first central tube, second central tube, and outlet jacket provided by this utility model for a heat pipe type low-temperature economizer can be fitted one-to-one onto multiple heat pipes. The water jacket and the first central tube form the water inlet section, and the water outlet jacket and the second central tube form the water outlet section. For heat pipes of different sizes, the gap area between the water inlet section and the water outlet section and the heat pipe can be adjusted by increasing or decreasing the number of the first central tube and the central jacket in the first central tube, so as to control the cooling water flow rate and meet the usage requirements. This allows the water jacket for the heat pipe type low-temperature economizer to be adapted to heat pipes of various sizes, thereby increasing its application range. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the water inlet sleeve in the water jacket of a heat pipe type low temperature economizer according to this utility model.

[0024] Figure 2 This is a schematic diagram of the structure of the water outlet sleeve in the water jacket of a heat pipe type low temperature economizer according to this utility model.

[0025] Figure 3 This is a schematic diagram of the structure of the middle sleeve in the water jacket of a heat pipe type low-temperature economizer according to this utility model.

[0026] Figure 4 This is a schematic diagram of a structure in which the number of central sleeves in each group of central tubes in a heat pipe type low-temperature economizer is zero.

[0027] Figure 5 This is a schematic diagram of the structure of a water jacket tube for a heat pipe type low-temperature economizer, where the number of central jacket tubes in each group of central tubes is one.

[0028] Figure 6 This is a schematic diagram of a structure in which the number of middle sleeves in each group of middle tubes in a heat pipe type low temperature economizer is two.

[0029] Figure 7 This is a cross-sectional view of a sealing component used in the water jacket of a heat pipe type low-temperature economizer according to this utility model.

[0030] In the picture:

[0031] 1. Inlet sleeve; 11. Inlet A; 12. Outlet A;

[0032] 2. Outlet sleeve; 21. Inlet B; 22. Outlet B;

[0033] 3. Middle sleeve; 31. Inlet C; 32. Outlet C;

[0034] 4. Sealing components;

[0035] 5. Heat pipe. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0037] In the description of this utility model, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] In the embodiments of this application, such as Figures 1 to 7 As shown, the water jacket for the heat pipe type low-temperature economizer includes an inlet jacket 1, an outlet jacket 2, and two sets of intermediate pipes. See [link / reference needed]. Figure 1 , Figure 2 and Figure 3 ;in,

[0040] The inlet sleeve 1 is provided with an inlet A11 and two sets of drain outlets A12, with the two sets of drain outlets A12 located near both ends of the inlet sleeve 1.

[0041] The water outlet sleeve 2 is equipped with an inlet B21 and a drain outlet B22; the number of inlets B21 is equal to the number of drain outlets A12, and their positions correspond one-to-one.

[0042] The central pipe includes at least one central sleeve 3. The number of central sleeves 3 in the two sets of central pipes is equal. The two sets of central pipes are the first central pipe and the second central pipe. The first central pipe and the second central pipe are both set between the inlet sleeve 1 and the outlet sleeve 2. The outlet end of the first central pipe is connected to the inlet end of the second central pipe through a pipe fitting. The pipe fitting and the inlet A11 are respectively set at both ends of the central pipe. The two sets of drain outlets A12 are connected to the first central pipe, and the two sets of inlet outlets B21 are connected to the second central pipe.

[0043] The inlet sleeve 1, the first middle pipe, the second middle pipe, and the outlet sleeve 2 are all fitted onto the heat pipe.

[0044] The inlet sleeve 1, the first middle pipe, the second middle pipe, and the outlet sleeve 2 in the water jacket of the heat pipe type low temperature economizer can be fitted one-to-one on multiple adjacent heat pipes 5. Since the first middle pipe and the second middle pipe are connected in parallel with the inlet sleeve 1 and the outlet sleeve 2 respectively, the inlet sleeve 1 and the first middle pipe form an inlet section, and the outlet sleeve 2 and the second middle pipe form an outlet section.

[0045] Increasing the number of central sleeves 3 in the first and second central pipes increases the gap area between the inlet and outlet sections and the heat pipe 5, thereby slowing down the flow rate of cooling water between the inlet and outlet sections and the heat pipe 5; decreasing the number of central sleeves 3 in the first and second central pipes decreases the gap area between the inlet and outlet sections and the heat pipe 5, thereby accelerating the flow rate of cooling water between the inlet and outlet sections and the heat pipe 5.

[0046] In actual use, the number of central sleeves 3 in the first and second central tubes can be determined according to the size of the heat pipe 5. For example, when the size of the heat pipe 5 is smaller than the standard size, the gap area between the inlet and outlet sections and the heat pipe 5 is larger than the usage requirements, and the flow rate of the cooling water will be lower than the set flow rate. At this time, the number of central sleeves 3 in the first and second central tubes can be reduced to reduce the gap area between the inlet and outlet sections and the heat pipe 5, thereby increasing the flow rate of the cooling water and enabling the cooling water flow rate to reach or approach the set flow rate.

[0047] When the size of heat pipe 5 is larger than the standard size, the gap area between the inlet and outlet sections and heat pipe 5 is smaller than the usage requirements, and the flow rate of cooling water will be greater than the set flow rate. At this time, the gap area between the inlet and outlet sections and heat pipe 5 can be increased by increasing the number of central sleeves 3 in the first and second central pipes, thereby reducing the flow rate of cooling water and enabling the flow rate of cooling water to reach or approach the set flow rate. This allows the cooling water to fully exchange heat with the high-temperature flue gas in heat pipe 5 in the inlet and outlet sections, thereby improving the recovery and utilization rate of heat energy.

[0048] In addition, the water jacket used in the heat pipe type low temperature economizer can effectively prevent excessive water flow resistance and also prevent excessive scouring of the heat pipe 5 by the cooling water, thereby improving the service life of the heat pipe 5.

[0049] It is worth noting that the standard size of the heat pipe 5 mentioned above refers to the size that is compatible with the inlet sleeve 1 or the outlet sleeve 2. That is, when the inlet sleeve 1 or the outlet sleeve 2 is fitted onto the heat pipe 5, the gap area between the inner diameter of the inlet sleeve 1 or the outlet sleeve 2 and the outer diameter of the heat pipe 5 meets the requirements of the cooling water flow rate. In this embodiment, the sizes of the inlet sleeve 1, the outlet sleeve 2 and the middle sleeve 3 are fixed sizes (inner diameter) and are the same.

[0050] In some embodiments, the aforementioned central sleeve 3 includes an inlet C31 and an outlet C32, see [reference needed]. Figure 3 ;in,

[0051] The number of inlets C31 is equal to the number of outlets A12, and their positions correspond one-to-one;

[0052] The number of drain outlets C32 is equal to the number of inlet outlets B21, and their positions correspond one-to-one;

[0053] To better illustrate the structure of the water jacket used in the heat pipe type low temperature economizer, this embodiment describes the structure with zero, one, and multiple central jackets 3 in each group of central pipes. The inlet jacket 1, the central jacket 3, and the outlet jacket 2 have the same dimensions, specifically the same inner diameter.

[0054] When the flow rate of the cooling water, determined by the gap area between the inlet sleeve 1 and the heat pipe 5, meets the design requirements, the operator does not need to install the middle pipe. The inlet sleeve 1 and outlet sleeve 2 are respectively fitted onto two adjacent heat pipes 5. Then, the set of drain outlets A12 and inlet B21, located away from inlet A11, are connected via pipe fittings. The set of drain outlets A12 and inlet B21 that are not connected are sealed with sealing components 4. (See [reference]). Figure 4 The inlet sleeve 1 and outlet sleeve 2 are connected in series, which is the same as the structure of water sleeves in the prior art. Multiple inlet sleeves 1 and outlet sleeves 2 are connected sequentially from the inlet end to the outlet end, so that the cooling water flows in an S-shape, so that the cooling water in the inlet sleeve 1 and outlet sleeve 2 can better exchange heat with the hot air (flue gas) in the heat pipe 5.

[0055] When the flow rate of cooling water, determined by the gap area between the inlet sleeve 1 and the heat pipe 5, is greater than the design requirement, the staff can add a middle pipe between the inlet sleeve 1 and the outlet sleeve 2. There are two sets of middle pipes, namely the first middle pipe and the second middle pipe. The number of middle sleeves 3 in the first middle pipe and the number of middle sleeves in the second middle pipe are both one.

[0056] The two sets of drain outlets A12 and the two sets of inlet outlets C31 on the middle sleeve 3 in the first middle pipe are connected together;

[0057] The two sets of inlets B21 and the two sets of outlets C32 on the middle sleeve 3 of the second middle pipe are connected together;

[0058] A set of drain outlets C32 on the central sleeve 3 of the first central pipe, away from the inlet A11, is connected to a set of inlet outlets C31 on the central sleeve 3 of the second central pipe, also away from the inlet A11. The set of drain outlets C32 on the central sleeve 3 of the first central pipe, near the inlet A11, and the set of inlet outlets C31 on the central sleeve 3 of the second central pipe, near the inlet A11, are sealed by a sealing component 4. (See [reference]) Figure 5 ;

[0059] When there are multiple central sleeves 3 in the first central pipe and multiple central sleeves 3 in the second central pipe, the multiple central sleeves 3 in the first central pipe and the multiple central sleeves 3 in the second central pipe are arranged sequentially from the water inlet end to the water outlet end.

[0060] In the first central pipe, two drain outlets C32 on the central sleeve 3 near the inlet end are respectively connected to two inlet outlets C31 on the central sleeve 3 near the outlet end. Two sets of drain outlets A12 are also connected to two sets of inlet outlets C31 on the central sleeve 3 near the inlet sleeve 1 in the first central pipe. The set of drain outlets C32 on the central sleeve 3 near the outlet end, away from the inlet outlet A11, is the outlet end of the first central pipe. The other set of drain outlets C12 on the central sleeve 3 near the outlet end... 32 is sealed by the sealing component 4, that is, multiple middle sleeves 3 in the first middle pipe are connected in sequence through all the inlet C31 and outlet C32, the outlet A12 is connected to the inlet C31 of the first middle sleeve 3, and the group of outlets C32 on the last middle sleeve 3 away from the inlet A11 is the outlet end of the first middle pipe; wherein, the first middle sleeve 3 and the last middle sleeve 3 mentioned above refer to the positions arranged from the inlet end to the outlet end;

[0061] In the second middle pipe, two drain outlets C32 on the middle sleeve 3 near the inlet end are respectively connected to two inlet outlets C31 on the middle sleeve 3 near the outlet end. Both sets of inlet outlets B21 are connected to two sets of drain outlets C32 on the middle sleeve 3 near the outlet sleeve 2 in the second middle pipe. The set of inlet outlets C31 on the middle sleeve 3 near the inlet end, away from inlet A11, is the inlet end of the second middle pipe. Another set of drain outlets C32 on the upper part is sealed by the sealing element 4; that is, multiple middle sleeves 3 in the second middle pipe are connected in sequence, the inlet B21 is connected to the drain outlet C32 of the last middle sleeve 3, and the set of inlets C31 on the first middle sleeve 3 that is far away from the inlet A11 is the inlet end of the second middle pipe; where the first middle sleeve 3 and the last middle sleeve 3 mentioned above refer to the positions arranged from the inlet end to the outlet end;

[0062] The outlet of the first central pipe is connected to the inlet of the second central pipe via a fitting, see [link to details]. Figure 6 (There are two central sleeves 3, and the connection method of multiple central sleeves 3 is the same.) This setting can increase the gap area between the inlet sleeve 1 and the outlet sleeve 2 and the heat pipe 5, so as to reduce the flow rate of cooling water and realize the adjustment of cooling water flow rate.

[0063] Preferably, each of the above-mentioned inlet A11, outlet A12, inlet B21, outlet B22, inlet C31, and outlet C32 is provided with an extension. The extension is a circular tubular structure, the outer diameter of the extension matches the inner diameter of the pipe fitting, and the axis of the extension coincides with the axis of the corresponding inlet A11, outlet A12, inlet B21, outlet B22, inlet C31, and outlet C32. The outer side wall of the extension is provided with external threads, and the pipe fitting is detachably installed on inlet A11, outlet A12, inlet B21, outlet B22, inlet C31, and outlet C32.

[0064] If it is necessary to seal inlet A11, outlet A12, inlet B21, outlet B22, inlet C31, and outlet C32, the sealing can be achieved using the aforementioned sealing member 4. The sealing member 4 has a cap-like structure, and its inner wall is provided with internal threads. (See [reference]). Figure 7 This allows the sealing component 4 to be installed on the extensions at the inlet A11, outlet A12, inlet B21, outlet B22, inlet C31, and outlet C32 via a threaded connection, making the installation and removal of the sealing component 4 more convenient and ensuring a good sealing effect.

[0065] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A water jacket tube for a heat pipe type low temperature economizer, characterized by: Including water inlet sleeve (1), water outlet sleeve (2) and two groups of middle tube; The water inlet sleeve (1) is provided with a water inlet A (11) and two groups of water outlet A (12), and the two groups of water outlet A (12) are respectively arranged near the two ends of the water inlet sleeve (1); The water outlet sleeve (2) is provided with a water inlet B (21) and a water outlet B (22); the number of the water inlet B (21) is equal to the number of the water outlet A (12), and the positions are one-to-one corresponding; The middle tube includes at least one middle sleeve (3), and the number of the middle sleeve (3) in the two groups of middle tube is equal. The two groups of middle tube are respectively a first middle tube and a second middle tube, and the first middle tube and the second middle tube are arranged between the water inlet sleeve (1) and the water outlet sleeve (2), and the water outlet end of the first middle tube and the water inlet end of the second middle tube are connected through a pipe joint, and the pipe joint is arranged near the two ends of the middle tube respectively; the two groups of water outlet A (12) are connected with the first middle tube, and the two groups of water inlet B (21) are connected with the second middle tube; The water inlet sleeve (1), the first middle tube, the second middle tube and the water outlet sleeve (2) are all arranged on the heat pipe (5).

2. The jacket tube for a heat pipe type low-temperature economizer according to claim 1, characterized by: The middle sleeve (3) includes a water inlet C (31) and a water outlet C (32); The number of the water inlet C (31) is equal to the number of the water outlet A (12), and the positions are one-to-one corresponding; The number of the water outlet C (32) is equal to the number of the water inlet B (21), and the positions are one-to-one corresponding; When the middle tube includes one middle sleeve (3), the two groups of water outlet A (12) and the two groups of water inlet C (31) on the middle sleeve (3) in the first middle tube are connected; the two groups of water inlet B (21) and the two groups of water outlet C (32) on the middle sleeve (3) in the second middle tube are connected; the group of water outlet C (32) on the middle sleeve (3) in the first middle tube away from the water inlet A (11) is connected with the group of water inlet C (31) on the middle sleeve (3) in the second middle tube away from the water inlet A (11), and the group of water outlet C (32) on the middle sleeve (3) in the first middle tube close to the water inlet A (11) is blocked by the blocking piece (4) with the group of water inlet C (31) on the middle sleeve (3) in the second middle tube close to the water inlet A (11). When the middle pipe comprises two or more middle sleeves (3), the multiple middle sleeves (3) in the first middle pipe and the multiple middle sleeves (3) in the second middle pipe are arranged in sequence from the water inlet end to the water outlet end; and in the first middle pipe, the two water outlet ports C (32) on the middle sleeve (3) close to the water inlet end are respectively connected in communication with the two water inlet ports C (31) on the middle sleeve (3) close to the water outlet end, the two groups of water inlet ports C (31) on the middle sleeve (3) close to the water inlet sleeve (1) are respectively connected in communication with the two groups of water outlet ports A (12), the water outlet port C (32) on the middle sleeve (3) close to the water outlet end and away from the water inlet port A (11) is the water outlet end of the first middle pipe, and the other group of water outlet ports C (32) on the middle sleeve (3) close to the water outlet end is blocked by the blocking piece (4); in the second middle pipe, the two water outlet ports C (32) on the middle sleeve (3) close to the water inlet end are respectively connected in communication with the two water inlet ports C (31) on the middle sleeve (3) close to the water outlet end, the two groups of water inlet ports B (21) on the middle sleeve (3) close to the water outlet sleeve (2) are respectively connected in communication with the two groups of water outlet ports C (32), the water inlet port C (31) on the middle sleeve (3) close to the water inlet end and away from the water inlet port A (11) is the water inlet end of the second middle pipe, and the other group of water outlet ports C (32) on the middle sleeve (3) close to the water inlet end is blocked by the blocking piece (4). The water outlet end of the first middle pipe is connected in communication with the water inlet end of the second middle pipe through a pipe fitting.

3. The jacketed tube for a thermotube type low-temperature economizer according to claim 2, characterized by: The blocking piece (4) is in a cover shape, and is connected to the water inlet port C (31) or the water outlet port C (32) through threads.

Images