Vertical coal economizer with high heat exchange efficiency

Abstract

The utility model relates to a vertical coal economizer with high heat exchange efficiency, and relates to a boiler device to solve the problem of low heat exchange efficiency of the existing coal economizer. The utility model comprises a shell, a sleeve, a partition, a tube sheet and two groups of heat exchange straight pipes. Four tube sheets are arranged in the shell. The four tube sheets sequentially divide the shell from top to bottom into a first chamber, a second chamber, a third chamber, a fourth chamber and a fifth chamber. The second chamber and the third chamber are communicated. The partition is arranged in the first chamber and divides the first chamber into a sixth chamber and a seventh chamber. The two groups of heat exchange straight pipes are arranged on the uppermost and lowermost tube sheets and communicate the first chamber and the fifth chamber. One group of heat exchange straight pipes communicates the sixth chamber, and the other group of heat exchange straight pipes communicates the seventh chamber. The sleeve is arranged on the two middle tube sheets and communicates the second chamber and the fifth chamber. The utility model increases the flow of flue gas and water, and improves the heat exchange efficiency of the coal economizer through multiple heat exchanges.

Description

Technical Field

[0001] This invention relates to a boiler device, specifically to an economizer. Background Technology

[0002] An economizer is a device installed at the bottom of the boiler flue to recover the waste heat of the exhaust gas. It heats the boiler feedwater to saturated water at the pressure of the steam drum. Because it absorbs the heat of the high-temperature flue gas, it reduces the exhaust gas temperature, saves energy, and improves efficiency.

[0003] During operation, the flue gas flowing through the economizer exchanges heat with the economizer's heat exchange tubes, reducing the flue gas temperature. Generally, the flue gas flows outside the heat exchange tubes, which are equipped with fins to improve heat exchange. However, because the flue gas flows from one end of the economizer to the other with a short residence time, the heat exchange efficiency is low. A large number of heat exchange tubes are needed to improve the heat exchange efficiency, resulting in a large space occupation, low equipment material utilization, and high cost. Summary of the Invention

[0004] To address the problem of low heat exchange efficiency in existing economizers, this invention provides a vertical economizer with high-efficiency heat exchange.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A high-efficiency heat exchange vertical economizer includes a shell, sleeves, baffles, tube sheets, and two sets of heat exchange straight tubes. The shell contains four tube sheets that sequentially divide the shell into a first chamber, a second chamber, a third chamber, a fourth chamber, and a fifth chamber from top to bottom. The second and third chambers are connected. A baffle is located within the first chamber and divides it into a sixth and a seventh chamber. Two sets of heat exchange straight tubes are located on the uppermost and lowermost tube sheets, connecting the first and fifth chambers. One set of heat exchange straight tubes connects to the sixth chamber, and the other set connects to the seventh chamber. Sleeves are located on the two middle tube sheets, connecting the second and fifth chambers. Each heat exchange straight tube in the set connected to the sixth chamber is fitted with a sleeve, with the two sleeves spaced apart. The sixth chamber has a flue gas inlet, the seventh chamber has a flue gas outlet, the fourth chamber has a water inlet, and the third chamber has a water outlet.

[0007] Preferably, each heat exchange straight tube in each group of heat exchange straight tubes is a threaded smoke tube.

[0008] Preferably, each heat exchange straight tube communicating with the chamber is provided with spiral fins, and the spiral fins are attached to the sleeve fitted on the heat exchange straight tube to form a spiral channel.

[0009] Preferably, the third chamber is provided with multiple transversely arranged baffles, which form a zigzag flow channel within the third chamber.

[0010] Preferably, the outlet is located near the inlet.

[0011] Preferably, the top and bottom of the housing are provided with flange cover plates. The top flange cover plate, the top tube sheet and the housing form a first chamber. A vertical partition plate is provided between the top flange cover plate and the top tube sheet. The bottom flange cover plate, the bottom tube sheet and the housing form a fifth chamber. Each flange cover plate is detachably connected to the housing.

[0012] Preferably, each heat exchange straight tube in each group of heat exchange straight tubes on the tube sheet located at the top and bottom of the shell is provided with an anti-wear tube at its end.

[0013] Preferably, the upper surface of the tube sheet at the top of the shell is provided with an anti-corrosion layer made of epoxy zinc-rich primer, and the surface of the anti-corrosion layer is provided with an expansion layer made of epoxy coal tar pitch paint. Along the thickness direction of the tube sheet, the expansion layer is provided with an insulation layer made of high thermal resistance castable, a refractory layer made of refractory castable, and a protective layer made of thermal shock resistant and wear-resistant material.

[0014] Preferably, the third chamber is provided with a manhole for maintenance, and the manhole is provided with a sealing flange.

[0015] Preferably, each sleeve is a threaded smoke pipe.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] In this invention, flue gas enters sequentially from the inlet into the sixth chamber, the heat exchange straight tube, and the fifth chamber, then returns to the seventh chamber and exits from the outlet. Water enters sequentially from the inlet into the fourth chamber, the gap between the sleeve and the heat exchange straight tube, the second chamber, and the third chamber, and exits from the outlet of the third chamber. Flowing through multiple chambers, the flue gas undergoes multiple heat exchanges with the flue gas. Simultaneously, the use of a sleeve to return the flue gas increases the flue gas flow, extends the heat exchange time, and improves the heat exchange efficiency. For the same heat exchange efficiency, the equipment occupies less space.

[0018] Second, the present invention uses straight tubes for heat exchange, which is more convenient for maintenance compared with U-shaped heat exchange tubes with transmission.

[0019] Third, the present invention sets up a heat exchange straight tube in the limited space of the shell, and performs multiple heat exchanges through flue gas and water backflow, thereby improving material utilization and reducing equipment manufacturing costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the present invention;

[0021] Figure 2 yes Figure 1 Sectional view II;

[0022] Figure 3 yes Figure 1 Sectional view II-II;

[0023] Figure 4 This is a schematic diagram of the wear-resistant protective structure of the present invention.

[0024] Reference numerals: 1. Shell; 2. Sleeve; 3. Baffle; 4. Tube sheet; 5. Heat exchange straight tube; 6. Spiral fin; 7. Baffle plate; 8. Flange cover plate; B. Second chamber; C. Third chamber; D. Fourth chamber; E. Fifth chamber; A1. Sixth chamber; A2. Seventh chamber; h1. Smoke inlet; h2. Smoke outlet; h3. Water inlet; h4. Water outlet; a. Wear-resistant tube; b. Anti-corrosion layer; c. Expansion layer; d. Fire-resistant layer; e. Insulation layer; f. Protective layer. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings: This embodiment is implemented under the premise of the technical solution of the present invention, and a detailed implementation method is given, but the protection scope of the present invention is not limited to the following embodiment.

[0026] Example 1: The following is combined with Figures 1-4 To illustrate this embodiment, this embodiment relates to a high-efficiency heat exchange vertical economizer, such as... Figures 1-3 As shown, the system includes a shell 1, a sleeve 2, a partition 3, tube sheets 4, and two sets of heat exchange straight tubes 5. The shell 1 contains four tube sheets 4, which sequentially divide the shell 1 from top to bottom into a first chamber (B), a second chamber (C), a third chamber (D), a fourth chamber (D), and a fifth chamber (E). The second chamber (B) and the third chamber (C) are connected. The partition 3 is located within the first chamber and divides it into a sixth chamber (A1) and a seventh chamber (A2). The two sets of heat exchange straight tubes 5 are located on the uppermost and lowermost tube sheets 4, connecting the first and fifth chambers. E is connected, one set of heat exchange straight tubes 5 is connected to the sixth chamber A1, and another set of heat exchange straight tubes 5 is connected to the seventh chamber A2. The sleeve 2 is set on the two tube sheets 4 in the middle and connects the second chamber B and the fifth chamber E. Each heat exchange straight tube 5 in the set of heat exchange straight tubes 5 connected to the sixth chamber A1 is fitted with a sleeve 2 and the two are set at intervals. The sixth chamber A1 is provided with a flue gas inlet h1, the seventh chamber A2 is provided with a flue gas outlet h2, the fourth chamber D is provided with a water inlet h3, and the third chamber C is provided with a water outlet h4.

[0027] In the fourth chamber D, water exchanges heat with the fifth chamber E and the heat exchange straight pipes 5 for flue gas inlet and outlet. The water then enters from the sleeve 2 and flows into the third chamber C, where it exchanges heat with the heat exchange straight pipes 5 for flue gas outlet and the water in the sleeve 2, resulting in multiple heat exchanges. The water then enters the second chamber B. Since the temperature of the heat exchange straight pipes 5 in the flue gas inlet section of chamber B is higher than that in the heat exchange straight pipes 5 in the sleeve 2 section, the water exchanges heat in the sleeve 2 section and then exchanges heat again in the second chamber B. At the same time, it exchanges heat with the heat exchange straight pipes 5 for flue gas outlet in the second chamber B (which is connected to the heat exchange straight pipe 5 in the seventh chamber A2). After heat exchange, the water flows into the third chamber C and exchanges heat with the two sets of heat exchange straight pipes 5 for the final time before flowing out from the outlet h4. Through multiple heat exchanges, the flue gas temperature is significantly reduced, improving the heat exchange efficiency of the economizer.

[0028] To prevent flue gas from clogging within the heat exchange straight tubes 5, improve heat exchange efficiency, and enhance thermal expansion, each heat exchange straight tube 5 in each group of heat exchange straight tubes 5 in this embodiment is a threaded flue tube. The threaded flue tube 5 has spiral grooves on both its inner and outer walls. The threaded tube wall creates a downward-flowing, high-speed rotating airflow, which, combined with the gravity of ash, completes pneumatic transport within the flue tube, solving the problem of easy ash accumulation in traditional economizers. Water is drawn from the fourth chamber D at the bottom of the shell 1, with the water flow direction opposite to the flue gas flow direction. This increases the heat exchange time between the flue gas and the threaded flue tube, raising the tube wall temperature and solving the low-temperature acid corrosion problem of traditional economizers. Simultaneously, it improves the safety, service life, and maintainability of the economizer. This saves production costs for enterprises and reduces coal consumption, electricity consumption, operating costs, and subsequent maintenance costs for users.

[0029] To further improve heat exchange efficiency and meet the thermal expansion requirements of the sleeve 2, optionally, each sleeve 2 may also be used as a threaded smoke tube.

[0030] Optionally, the threaded smoke pipe is made of 20GB3087 steel.

[0031] To further improve heat exchange efficiency, each heat exchange straight tube 5 connected to the sixth chamber A1 in this embodiment is provided with spiral fins 6. The spiral fins 6 are attached to the sleeve 2 sleeved on the heat exchange straight tube 5 to form a spiral channel. The spiral fins 6 have two functions: first, they increase the heat exchange area of ​​the heat exchange straight tube 5; second, they increase the heat exchange time of the water heat exchange straight tube 5, so that heat can be fully exchanged.

[0032] To further increase the water flow and improve the heat exchange efficiency between the water and the flue gas heat exchange straight pipe 5, this embodiment provides a plurality of transversely arranged baffles 7 in the third chamber C. The baffles 7 form a zigzag flow channel in the third chamber C to increase the water flow.

[0033] To further increase the water flow, the outlet h4 is positioned adjacent to the inlet h3.

[0034] To facilitate maintenance and cleaning of flue gas particles in the heat exchange straight tube 5, the first chamber, and the fifth chamber, this embodiment provides a flange cover plate 8 on the shell 1. The specific structure is as follows: flange cover plates 8 are provided at the top and bottom of the shell 1. The first chamber is formed between the top flange cover plate 8, the top tube sheet 4, and the shell 1. A vertical partition plate 3 is provided between the top flange cover plate 8 and the top tube sheet 4. The fifth chamber E is formed between the bottom flange cover plate 8, the bottom tube sheet 4, and the shell 1. Each flange cover plate 8 is detachably connected to the shell 1.

[0035] To facilitate the removal of scale, the third chamber C may optionally be equipped with a manhole for maintenance, and the manhole may be equipped with a sealing flange.

[0036] Compared with existing economizers, this embodiment only requires the flange cover plate 8 to be removed to clean the soot. At the same time, the flue gas circulates and exchanges heat in the pipe. After multiple heat exchanges, the heat exchange efficiency can be improved.

[0037] To improve the service life of the heat exchange straight tube 5, reduce the impact and wear of particulate matter in the flue gas on the heat exchange straight tube 5, and prevent cracking, this embodiment provides an anti-wear protection structure on the tube sheet 4 at the top of the shell 1, such as... Figure 4 As shown, the anti-wear protection structure includes multiple anti-wear tubes a. Each heat exchange straight tube 5 in each group of heat exchange straight tubes 5 on the tube sheet 4 located at the top and bottom of the shell 1 is provided with an anti-wear tube a at its end. The anti-wear tube a and the end of the heat exchange straight tube 5 can be connected by welding.

[0038] To ensure uniform heating of the tube sheet 4 at the flue gas inlet, such as Figure 4 As shown, the wear-resistant protection structure in this embodiment also includes an anti-corrosion layer b, an expansion layer c, an insulation layer e, and a protective layer f. The upper surface of the tube sheet 4 at the top of the shell 1 is provided with an anti-corrosion layer b made of epoxy zinc-rich primer. The surface of the anti-corrosion layer b is provided with an expansion layer c made of epoxy coal tar pitch paint. Along the thickness direction of the tube sheet 4, the expansion layer c is provided with an insulation layer e made of high thermal resistance castable, a refractory layer d made of refractory castable, and a protective layer f made of thermal shock resistant and wear-resistant material.

[0039] In this embodiment, the protective layer f, the fire-resistant layer d, and the heat insulation layer e are arranged sequentially along the flue gas direction, and each of the protective layer f, the fire-resistant layer d, and the heat insulation layer e is covered by an expansion layer c on all sides.

[0040] This invention alters the original location of flue gas vortex generation by adding an anti-wear tube, causing the vortex to be generated in the anti-wear section. This effectively prevents wear on the threaded flue tube wall. When the anti-wear tube becomes severely worn, it can be replaced. Previously, if the heat exchange straight tube wore out, it had to be replaced entirely, increasing maintenance costs. After the improvement, only partial replacement is needed. Simultaneously, utilizing the high thermal resistance of the material, an expansion layer and an insulation layer are incorporated to separate the flue gas heat from the tube sheet, preventing the tube sheet from cracking due to heat.

[0041] This invention features an insulation layer composed of five materials, possessing both high-strength wear resistance and high thermal resistance insulation properties. By altering the original location of flue gas vortex generation through a special structure, the vortex is generated in the wear-resistant section, effectively preventing wear on the heat exchanger straight tube walls. Utilizing the high thermal resistance of the materials, flue gas heat is separated from the tube sheet, while simultaneously enhancing water-cooling protection for the tube sheet, effectively improving the service life and operational reliability of the threaded flue tubes. This reduces the user's maintenance workload and saves on operating costs.

[0042] While the present invention has been described in detail through specific embodiments, those skilled in the art should understand that the above examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A high-efficiency heat exchange vertical economizer, characterized in that, The system includes a shell (1), a sleeve (2), a partition (3), a tube sheet (4), and two sets of heat exchange straight tubes (5). The shell (1) is provided with four tube sheets (4), which divide the shell (1) into a first chamber, a second chamber (B), a third chamber (C), a fourth chamber (D), and a fifth chamber (E) from top to bottom. The second chamber (B) and the third chamber (C) are connected. The partition (3) is set in the first chamber and divides the first chamber into a sixth chamber (A1) and a seventh chamber (A2). The two sets of heat exchange straight tubes (5) are set on the uppermost and lowermost tube sheets (4) and connect the first chamber and the fifth chamber (E). One set of heat exchange straight tubes (5) is connected to the sixth chamber (A1), and another set of heat exchange straight tubes (5) is connected to the seventh chamber (A2). The sleeve (2) is set on the two tube sheets (4) in the middle and connects the second chamber (B) and the fifth chamber (E). Each heat exchange straight tube (5) in the set of heat exchange straight tubes (5) connected to the sixth chamber (A1) is fitted with a sleeve (2) and the two are spaced apart. The sixth chamber (A1) is provided with a flue gas inlet (h1), the seventh chamber (A2) is provided with a flue gas outlet (h2), the fourth chamber (D) is provided with a water inlet (h3), and the third chamber (C) is provided with a water outlet (h4). Each heat exchange straight tube (5) connected to the sixth chamber (A1) is provided with spiral fins (6), and the spiral fins (6) are attached to the sleeve (2) sleeved on the heat exchange straight tube (5) to form a spiral channel; The upper surface of the tube sheet (4) at the top of the shell (1) is provided with an anti-corrosion layer (b) made of epoxy zinc-rich primer. The surface of the anti-corrosion layer (b) is provided with an expansion layer (c) made of epoxy coal tar paint. Along the thickness direction of the tube sheet (4), the expansion layer (c) is provided with an insulation layer (e) made of high thermal resistance castable, a refractory layer (d) made of refractory castable, and a protective layer (f) made of thermal shock resistant and wear resistant material.

2. The vertical economizer with high-efficiency heat exchange according to claim 1, characterized in that, Each heat exchange straight tube (5) in each group of heat exchange straight tubes (5) is a threaded smoke tube.

3. The vertical economizer with high-efficiency heat exchange according to claim 1, characterized in that, The third chamber (C) is equipped with multiple transversely arranged baffles (7), which form a zigzag flow channel in the third chamber (C).

4. The vertical economizer with high-efficiency heat exchange according to claim 1, characterized in that, The outlet (h4) is located near the inlet (h3).

5. A vertical economizer for high-efficiency heat exchange according to claim 1, characterized in that, The shell (1) is provided with flange cover plates (8) at the top and bottom. The flange cover plate (8) at the top, the tube plate (4) at the top and the shell (1) form a first chamber. A vertical partition plate (3) is provided between the flange cover plate (8) at the top and the tube plate (4) at the top. The flange cover plate (8) at the bottom, the tube plate (4) at the bottom and the shell (1) form a fifth chamber (E). Each flange cover plate (8) is detachably connected to the shell (1).

6. A vertical economizer for high-efficiency heat exchange according to any one of claims 1-5, characterized in that, Each heat exchange straight tube (5) in each group of heat exchange straight tubes (5) on the tube sheet (4) located at the top and bottom of the shell (1) is provided with an anti-wear tube (a) at the end.

7. A vertical economizer for high-efficiency heat exchange according to claim 1, characterized in that, The third chamber (C) is equipped with a maintenance manhole, and the manhole is equipped with a sealing flange.

8. A vertical economizer for high-efficiency heat exchange according to claim 1, characterized in that, Each sleeve (2) is a threaded smoke pipe.

Images