A high and low temperature flue gas energy saver

Abstract

This invention provides a high and low temperature flue gas energy saver, comprising: a shell: the shell includes a high-temperature flue gas zone and a low-temperature flue gas zone, which are distributed sequentially along the flue gas flow direction. Flue gas enters from the inlet of the high-temperature flue gas zone and exits from the outlet of the low-temperature flue gas zone; a first heat transfer tube: the first heat transfer tube is disposed inside the shell and located in the high-temperature flue gas zone. A first liquid inlet is provided on one side of the shell, and the inlet of the first heat transfer tube is inserted into the first liquid inlet; a second heat transfer tube: the inlet of the second heat transfer tube is connected to the outlet of the first heat transfer tube and located in the low-temperature flue gas zone. A second liquid outlet is provided on one side of the shell, and the outlet of the second heat transfer tube is inserted into the second liquid outlet; a medium: the medium enters the cavity of the first heat transfer tube from the first liquid inlet, and the temperature difference between the flue gas entering the inlet of the high-temperature flue gas zone and the medium entering the inlet of the first heat transfer tube is controlled at 60℃-90℃.

Description

Technical Field

[0001] This invention relates to the field of energy-saving devices, and in particular to a high and low temperature flue gas energy-saving device. Background Technology

[0002] A biomass boiler is a boiler device that uses organic materials such as biomass pellets, wood blocks, sawdust, straw, and certain agricultural waste as fuel. It heats water by burning fuel to produce hot water or steam, which is used for heating, providing domestic hot water, or for industrial purposes.

[0003] Eco-friendly devices are used in boiler operating equipment to recover heat from the flue gas at the boiler tail end. The recovered heat is used to preheat the boiler feedwater or other media, which can greatly improve heat exchange efficiency, improve boiler operating efficiency, reduce energy waste, and improve overall thermal efficiency. This not only reduces fuel consumption but also reduces environmental pollution, making it an effective energy-saving and emission-reduction measure.

[0004] Currently, after the flue gas from the boiler tail enters the economizer, the water flow inside the economizer's water pipes absorbs the heat from the flue gas. However, the large temperature difference between the inside and outside of the water pipes after the flue gas enters the economizer causes condensation to form on the outer wall of the water pipes. This condensation causes ash from the flue gas to adhere to the outer wall of the water pipes. Since the ash in the flue gas contains corrosive substances such as sulfides, it accelerates the corrosion of the water pipes and reduces the service life of the economizer. Summary of the Invention

[0005] In view of this, the purpose of this utility model is to provide a high and low temperature flue gas energy saver to solve the problem of condensation on the outer wall of existing water pipes.

[0006] To solve the above-mentioned technical problems, the technical solution used in this utility model is as follows:

[0007] The high and low temperature flue gas energy-saving device of this utility model includes:

[0008] Shell: The shell includes a high-temperature flue gas zone and a low-temperature flue gas zone, which are distributed sequentially along the flue gas flow direction. Flue gas enters from the inlet of the high-temperature flue gas zone and exits from the outlet of the low-temperature flue gas zone.

[0009] First heat transfer tube: The first heat transfer tube is disposed inside the shell and located in the high-temperature flue gas zone. A first liquid inlet is provided on one side of the shell, and the input end of the first heat transfer tube is inserted into the first liquid inlet.

[0010] Second heat transfer tube: The input end of the second heat transfer tube is connected to the output end of the first heat transfer tube. The first heat transfer tube is located in the low-temperature flue gas zone. A second liquid outlet is opened on one side of the shell. The output end of the second heat transfer tube is inserted into the second liquid outlet.

[0011] Medium: The medium enters the cavity of the first heat transfer tube from the first liquid inlet, and the temperature difference between the flue gas entering the input end of the high-temperature flue gas zone and the medium entering the input end of the first heat transfer tube is controlled at 60℃-90℃.

[0012] Preferably, a second temperature sensor is provided at the output end of the first heat transfer tube.

[0013] Preferably, the output end of the first heat transfer tube and the input end of the second heat transfer tube extend outside the housing.

[0014] Preferably, the medium is water flow, the output end of the second heat transfer tube is connected to an output pipe, the output end of the output pipe is connected to a soft water tank, the other input end of the soft water tank is connected to a water softener, the water softener provides cold water to the soft water tank, and the hot water flowing out from one output end of the soft water tank is supplied to a boiler or other equipment that requires heat energy.

[0015] Preferably, another output end of the soft water tank is connected to a water supply pipe, and the end of the water supply pipe away from the soft water tank is connected to the input end of the first heat transfer pipe.

[0016] Preferably, the output end of the output pipe is connected to an electric three-way valve, one opening of the electric three-way valve is connected to an input pipe, the end of the input pipe away from the electric three-way valve is connected to an input end of the soft water tank, a mixing device is connected to the water supply pipe, and the other opening of the electric three-way valve is connected to a neutralization pipe, the end of the neutralization pipe away from the electric three-way valve is connected to an input end of the mixing device.

[0017] Preferably, a first thermometer is connected to the water supply pipe. The first thermometer is located at the output end of the mixer and is used to measure the temperature of the water flowing out of the output end of the mixer.

[0018] Preferably, a circulating pump set is provided on the water supply pipe, and the water mixer, the first thermometer and the circulating pump set are arranged in sequence along the direction of water flow. The circulating pump set is used to regulate the flow rate of the water in circulation.

[0019] Preferably, the circulating pump set includes a main circulating pump and a standby circulating pump. The main circulating pump is connected to the water supply pipe and is used to regulate the flow rate of the water supplied to the energy-saving device by the water supply pipe. The standby circulating pump is connected in parallel with the main circulating pump.

[0020] Preferably, the first heat transfer tube and the second heat transfer tube are made of carbon steel.

[0021] The beneficial effects of this invention are as follows: When flue gas enters the cavity of the shell, it first passes through the high-temperature flue gas zone. During the process of the flue gas flowing from the inlet to the outlet of the high-temperature flue gas zone, the water in the first heat transfer tube absorbs the heat in the flue gas, causing the temperature of the flue gas to decrease when it enters the low-temperature flue gas zone. After the water absorbs the heat, it enters the second heat transfer tube. The temperature of the flue gas entering the low-temperature flue gas zone is higher than the temperature of the water that absorbs the heat and enters the second heat transfer tube. The water in the second heat transfer tube continues to absorb the heat from the flue gas entering the low-temperature flue gas zone until the flue gas is discharged from the outlet of the low-temperature flue gas zone and the water is discharged from the outlet of the second heat transfer tube. The water absorbs the heat in the flue gas and can be used as a heat source to supply the boiler or other equipment that requires heat energy, thereby improving the thermal efficiency of the entire system and achieving the purpose of reducing energy consumption and saving energy.

[0022] The temperature difference between the flue gas entering the high-temperature flue gas zone and the medium entering the first heat transfer tube is controlled between 60℃ and 90℃. Compared to existing technologies where the water entering the first heat transfer tube is cold, the temperature difference between the water and the flue gas is large, leading to condensation on the outer wall of the first heat transfer tube. In this application, the initial temperature difference between the entering medium and the entering flue gas is controlled to a range where condensation will not occur on the outer wall of the first heat transfer tube. After being heated in the high-temperature flue gas zone, the water enters the low-temperature flue gas zone. After the flue gas exchanges heat with the medium in the high-temperature flue gas zone, its temperature decreases. At this time, the temperature difference between the medium and the flue gas further narrows, thereby further reducing the problem of condensation on the outer wall of the second heat transfer tube. The ash in the flue gas is difficult to adhere to the outer wall of the first and second heat transfer tubes. Therefore, when the flue gas passes through the shell cavity and is discharged, it will carry away the ash. The heavier dust will fall to the bottom of the flue gas inlet shell cavity, thereby reducing the situation where some corrosive substances such as sulfides in the ash accelerate the corrosion of the water pipes, and thus improve the service life of the energy saver.

[0023] The temperature difference between the incoming flue gas and the incoming medium is controlled between 60℃ and 90℃. A temperature difference below 60℃ will affect the heat exchange efficiency between the medium and the flue gas. When the temperature difference is higher than 90℃, condensation will occur on the outer wall of the first heat transfer tube. Therefore, this application takes into account the heat exchange efficiency of the energy-saving device while improving its service life. Attached Figure Description

[0024] The above and other objects, features, and advantages of the invention will become clearer through a more detailed description of the preferred embodiments illustrated in the accompanying drawings. The same reference numerals denote the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of the invention.

[0025] Figure 1 This is a front view of the energy-saving device.

[0026] Figure 2 This is the right view of the energy-saving device.

[0027] Figure 3 This is the left view of the energy-saving device.

[0028] Figure 4 This is a top view of the energy-saving device.

[0029] Figure 5 This is a system diagram of an embodiment of this application.

[0030] In the diagram: 1. Shell; 11. High-temperature flue gas zone; 12. Low-temperature flue gas zone; 13. First liquid inlet; 14. First liquid outlet; 15. Second liquid inlet; 16. Second liquid outlet; 17. Inspection door; 2. Flue gas inlet shell; 21. Flue gas inlet; 3. Flue gas outlet shell; 31. Flue gas outlet; 41. First heat transfer tube; 42. Connecting pipe; 43. Second heat transfer tube; 44. Output pipe; 45. Input pipe; 46. Water supply pipe; 47. Neutralization pipe; 48. Spare pipe; 5. Electric three-way valve; 61. Soft water tank; 62. Water softener; 7. Mixer; 8. First thermometer; 9. Circulation pump set; 91. Main circulation pump; 92. Spare circulation pump. Detailed Implementation

[0031] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to the accompanying drawings.

[0032] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to and integrated with the other component, or there may be an intervening component present. The terms "mounted," "one end," "the other end," and similar expressions used in this document are for illustrative purposes only.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] Figures 1-5This invention provides a high and low temperature flue gas energy saver, including a housing 1. The housing 1 has a flow cavity inside, which is a cavity with corresponding two through-holes. A flue gas inlet shell 2 and a flue gas outlet shell 3 are respectively installed at both ends of the housing 1. The cavity of the flue gas inlet shell 2, the flow cavity and the cavity of the flue gas outlet shell 3 are connected. A flue gas inlet 21 is opened on the side wall of the flue gas inlet shell 2, and a flue gas outlet 31 is opened on the side of the flue gas outlet shell 3 away from the flue gas inlet 21. High temperature flue gas enters the cavity of the flue gas inlet shell 2 from the flue gas inlet 21, and after passing through the flow cavity, the flue gas enters the cavity of the flue gas outlet shell 3. Finally, the flue gas is discharged from the flue gas outlet 31. The housing 1 includes a high temperature flue gas zone 11 and a low temperature flue gas zone 12. The high temperature flue gas zone 11 and the low temperature flue gas zone 12 are distributed sequentially along the flue gas flow direction. The high temperature flue gas zone 11 is close to the flue gas inlet shell 2, and the low temperature flue gas zone 12 is close to the flue gas outlet shell 3.

[0035] The shell 1 is provided with a first heat transfer tube 41 and a second heat transfer tube 43 connected in series. Both the first heat transfer tube 41 and the second heat transfer tube 43 are a series of parallel serpentine tubes. The first heat transfer tube 41 and the second heat transfer tube 43 are made of carbon steel, which reduces the manufacturing cost of the first heat transfer tube 41 and the second heat transfer tube 43, thereby reducing the manufacturing cost of the energy saver. In addition, the high thermal conductivity of carbon steel makes the heat transfer efficiency of the first heat transfer tube 41 and the second heat transfer tube 43 high, which can transfer the heat of the flue gas to the medium inside the tube more quickly and effectively.

[0036] The first heat transfer tube 41 is located in the high-temperature flue gas zone 11, and the second heat transfer tube 43 is located in the low-temperature flue gas zone 12. A first liquid inlet 13 is provided at the bottom of the shell 1 on the side away from the flue gas inlet 21. One end of the first heat transfer tube 41 is inserted into the first liquid inlet 13 and extends out of the outer wall of the shell 1. The first liquid inlet 13 is located at the input end of the high-temperature flue gas zone 11. The external medium can enter the first heat transfer tube 41 through the first liquid inlet 13. In this embodiment, the medium is water. Depending on the scenario, the medium can also be heat transfer oil. A first liquid outlet 14 is provided on the side of the shell 1 near the first liquid inlet 13. The first liquid outlet 14 is located at the output end of the high-temperature flue gas zone 11. The other end of the first heat transfer tube 41 is inserted into the first liquid outlet 14 and extends out of the outer wall of the shell 1.

[0037] Correspondingly, a second liquid inlet 15 is provided on the side of the shell 1 near the first liquid outlet 14. The second liquid inlet 15 is located at the input end of the low-temperature flue gas zone 12. One end of the second heat transfer tube 43 is inserted into the second liquid inlet 15 and extends out of the outer wall of the shell 1. A second liquid outlet 16 is provided on the side of the shell 1 near the second liquid inlet 15. The second liquid outlet 16 is located at the output end of the low-temperature flue gas zone 12. The other end of the second heat transfer tube 43 is inserted into the second liquid outlet 16. A connecting pipe 42 is provided between the first heat transfer tube 41 and the second heat transfer tube 43. One end of the connecting pipe 42 is connected to the output end of the first heat transfer tube 41, and the other end of the connecting pipe 42 is connected to the input end of the second heat transfer tube 43.

[0038] Water flows into the first heat transfer tube 41 from the first inlet 13. The water flows along the cavity of the first heat transfer tube 41 to the outlet of the first heat transfer tube 41. Then, the water flows from the outlet of the first heat transfer tube 41 into the connecting tube 42. The water flows through the cavity of the connecting tube 42 into the second heat transfer tube 43. The water flows along the cavity of the second heat transfer tube 43 to the outlet of the second heat transfer tube 43 and is discharged.

[0039] The flue gas temperature discharged from the boiler is around 400℃. The flue gas first passes through the economizer and air preheater to absorb heat. After absorbing heat, the flue gas temperature is around 100℃-160℃. Then, the flue gas enters the inlet shell 2 cavity from the flue gas inlet 21. When the flue gas enters the flow cavity, it first passes through the high-temperature flue gas zone 11. During the flow from the inlet to the outlet of the high-temperature flue gas zone 11, the water flow in the first heat transfer tube 41 absorbs heat from the flue gas, causing the flue gas to enter the low-temperature flue gas zone 12. The temperature of the flue gas will decrease. After the water that has absorbed heat enters the second heat transfer tube 43, the temperature of the flue gas entering the low-temperature flue gas zone 12 is higher than the temperature of the water that has absorbed heat and entered the second heat transfer tube 43. The water in the second heat transfer tube 43 continues to absorb the heat from the flue gas entering the low-temperature flue gas zone 12 until the flue gas is discharged from the flue gas outlet 31 and the water is discharged from the output end of the second heat transfer tube 43. The water absorbs the heat in the flue gas and can be used as a heat source to supply the boiler or other equipment that needs heat energy, thereby improving the thermal efficiency of the entire system and achieving the purpose of reducing energy consumption and saving energy.

[0040] When the temperature of the flue gas entering from the flue gas inlet 21 is around 160°C, the temperature of the water flowing into the first heat transfer tube 41 through the first liquid inlet 13 is around 70°C. This results in a temperature difference of around 90°C between the water in the first heat transfer tube 41 and the flue gas. Compared to the prior art, where the water entering the first heat transfer tube 41 is cold water, the temperature difference between the water and the flue gas is larger, leading to condensation on the outer wall of the first heat transfer tube 41. In this application, the initial temperature difference between the incoming water and the flue gas entering the flue gas inlet 21 is controlled to a range where condensation will not occur on the outer wall of the first heat transfer tube 41. After being heated in the high-temperature flue gas zone 11, the water enters the low-temperature flue gas zone 12, at which point the water temperature itself reaches at least around 80°C. The flue gas temperature decreases after heat exchange with the water flow in the high-temperature flue gas zone 11, and the flue gas temperature entering the low-temperature flue gas zone is around 120℃. At this time, the temperature difference between the water flow and the flue gas is further reduced, thereby further reducing the problem of condensation on the outer wall of the second heat transfer tube 43. The ash in the flue gas is difficult to adhere to the outer wall of the first heat transfer tube 41 and the second heat transfer tube 43. Therefore, when the flue gas passes through the flow cavity and is discharged from the flue gas outlet 31, it will carry away the ash. The heavier dust will fall to the bottom of the flue gas inlet shell 2 cavity, thereby reducing the situation where some corrosive substances such as sulfides in the ash accelerate the corrosion of the water pipe, and thus improve the service life of the energy saver. Compared with the existing energy savers, the service life of the energy saver of this application is 5-6 times that of the existing energy savers.

[0041] The temperature of the water entering the first heat transfer tube 41 is adjusted according to the temperature of the flue gas entering from the flue gas inlet 21. The temperature difference between the flue gas and the water is controlled between 60℃ and 90℃. If the temperature difference is below 60℃, the heat exchange efficiency between the water and the flue gas will be affected. If the temperature difference is above 90℃, condensation will occur on the outer wall of the first heat transfer tube 41. Therefore, this application takes into account the heat exchange efficiency of the energy saver while improving its service life.

[0042] A dust removal port is provided on the side of the smoke inlet shell 2 away from the flue gas inlet 21. An inspection door 17 is installed on the side of the smoke inlet shell 2 near the dust removal port. When the inspection door 17 is closed, it can seal the dust removal port. When the inspection door 17 is opened, the dust removal port can be exposed, and the staff can clean the dust that has fallen to the bottom of the smoke inlet shell 2 through the dust removal port.

[0043] The output end of the second heat transfer tube 43 is connected to an output tube 44, and the other end of the output tube 44 is connected to an electric three-way valve 5. One opening of the electric three-way valve 5 is connected to an input tube 45. The end of the input tube 45 away from the electric three-way valve 5 is connected to a soft water tank 61. The other input end of the soft water tank 61 is connected to a water softener 62, which is connected to an external water source and provides cold water to the soft water tank 61. The heat-absorbing water flowing out of the output end of the second heat transfer tube 43 flows through the output tube 44 to the electric three-way valve 5. After opening valve 5, the electric three-way valve 5 opens the opening connected to the input pipe 45, and the water flows into the input pipe 45 through the opening of the electric three-way valve 5. Finally, the water flows through the cavity of the input pipe 45 into the soft water tank 61. The water in the soft water tank 61 that has absorbed heat is neutralized with the cold water provided by the water softener 62, and the temperature of the mixed water in the soft water tank 61 is adjusted to the corresponding temperature. The neutralized hot water flows out from one of the output ends of the soft water tank 61 and is supplied to the boiler or other equipment that requires heat energy.

[0044] Another output end of the soft water tank 61 is connected to a water supply pipe 46. The end of the water supply pipe 46 away from the soft water tank 61 is connected to the input end of the first heat transfer pipe 41. Therefore, a portion of the hot water neutralized in the soft water tank 61 provides water flow for heat exchange to the energy saver, thereby achieving the effect of saving resources.

[0045] A mixing valve 7 is connected to the water supply pipe 46. Another opening of the electric three-way valve 5 is connected to a neutralization pipe 47. The end of the neutralization pipe 47 away from the electric three-way valve 5 is connected to one input end of the mixing valve 7. A first thermometer 8 is connected to the water supply pipe 46. The first thermometer 8 is located at the output end of the mixing valve 7. The first thermometer 8 is used to measure the temperature of the water flowing out of the output end of the mixing valve 7. When the required temperature at the output end of the first heat transfer tube 41 is higher than the temperature of the hot water after neutralization in the soft water tank 61, the electric three-way valve 5 opens the opening connected to the neutralization pipe 47, so that part of the high-temperature water that has absorbed heat enters the mixing valve 7 through the cavity of the neutralization pipe 47, raising the water temperature in the mixing valve 7 until the water temperature in the mixing valve 7 reaches the required water temperature at the input end of the first heat transfer tube 41. Under the action of the mixing valve 7, the temperature of the water flowing into the first heat transfer tube 41 can be adjusted so that the temperature of the water flowing into the first heat transfer tube 41 can be changed according to the temperature of the flue gas entering the flue gas inlet 21.

[0046] A circulation pump group 9 is installed on the water supply pipe 46. The mixing device 7, the first thermometer 8, and the circulation pump group 9 are arranged in sequence along the water flow direction. The circulation pump group 9 includes a main circulation pump 91 and a standby circulation pump 92. The main circulation pump 91 is connected to the water supply pipe 46 and is used to regulate the flow rate of the water supplied by the water supply pipe 46 to the energy saver. A standby pipe 48 is connected to the outside of the water supply pipe 46. Both ends of the standby pipe 48 are connected to the corresponding parts of the water supply pipe 46. The standby pipe 48 is arranged in parallel with the water supply pipe 46 connected to the part of the main circulation pump 91. The standby circulation pump 92 is installed on the standby pipe 48. When the main circulation pump 91 is damaged, the standby circulation pump 92 is started and the water flows through the standby pipe 48.

[0047] A second thermometer is installed on the connecting pipe 42. The second thermometer is used to measure the temperature of the water flowing out of the output end of the first heat transfer tube 41. This allows us to know the amount of heat absorbed by the water after it flows through the high-temperature flue gas zone 11. When the second thermometer detects that the temperature of the water flowing out of the output end of the first heat transfer tube 41 is lower than the expected water temperature, the water flow rate is too fast. This means that the water does not fully absorb the heat from the flue gas in the high-temperature flue gas zone 11, thus affecting the heat exchange efficiency of the energy saver. Therefore, the main circulation pump 91 will automatically adjust the water flow rate to slow it down, allowing the water to fully absorb the heat from the flue gas and improve the heat exchange efficiency of the energy saver.

[0048] Therefore, the steps for adjusting the medium flow rate are as follows: S1: The second thermometer detects the temperature of the medium flowing out of the output end of the first heat transfer tube 41. If the medium temperature detected by the second thermometer reaches the preset temperature, the existing medium flow rate is maintained. If the medium temperature detected by the second thermometer is lower than the preset temperature, the process proceeds to step S2.

[0049] S2: The main circulation pump 91 slows down the medium flow rate. The second thermometer detects the medium temperature flowing out of the output end of the first heat transfer tube 41 in real time. If the medium temperature detected by the second thermometer does not reach the preset temperature, the main circulation pump 91 continues to slow down the medium flow rate until the medium temperature detected by the second thermometer reaches the preset temperature.

[0050] This application determines the heat exchange efficiency between water and flue gas by real-time detection of the water temperature flowing out of the first heat transfer tube 41. Furthermore, when the heat exchange efficiency between water and flue gas is determined to be low, the main circulation pump 91 can automatically adjust the water flow rate to improve the heat exchange efficiency, reduce the situation of low heat exchange efficiency between water and flue gas, thereby better absorbing heat and saving resources.

[0051] Furthermore, compared to the case where the second temperature sensor is set at the output end of the second heat transfer tube 43, if the second temperature sensor detects that the temperature of the water flowing out of the output end of the second heat transfer tube 43 is low, the main circulation pump 91 will slow down the water flow rate. At this time, the water flow that does not meet the temperature standard has already flowed out of the output end of the second heat transfer tube 43 and entered the output pipe 44. The water flow that does not meet the temperature standard has already flowed out of the energy-saving device. Therefore, the water flow that does not meet the temperature standard and flows out of the energy-saving device is difficult to continue to absorb heat from the flue gas for heat exchange, thereby reducing the heat exchange rate between the water flow and the flue gas. In this application, the temperature of the water flow is detected at the output end of the first heat transfer tube 41. When the water flow temperature is detected to be below the standard, the main circulation pump 91 slows down the water flow rate. The water flow from the output end of the first heat transfer tube 41 enters the second heat transfer tube 43. After that, the water flow entering the second heat transfer tube 43 can continue to exchange heat with the flue gas in the low temperature flue gas zone 12, thereby reducing the situation of low heat exchange rate between the water flow and the flue gas.

[0052] In this application, both the output end of the first heat exchange tube and the input end of the second heat exchange tube extend out of the side wall of the housing 1, the connecting pipe 42 is located outside the housing 1, and the second thermometer is located outside the housing 1. Compared to the case where the output end of the first heat exchange tube and the input end of the second heat exchange tube are located inside the housing 1, the second thermometer being located inside the housing 1 makes it inconvenient for staff to clean and repair when the first or second heat exchange tube becomes blocked or when the second thermometer malfunctions and needs maintenance. However, in this application, when it is necessary to clean and repair the first heat exchange tube, the second heat exchange tube, or the second thermometer, staff can do so outside the housing 1, making it more convenient for staff to clean and repair the first heat exchange tube, the second heat exchange tube, and the second thermometer.

[0053] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0054] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0055] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A high and low temperature flue gas energy saver, characterized in that, include: Shell: The shell has a smoke inlet shell and a smoke outlet shell installed at both ends. The smoke inlet shell has a smoke inlet on its side wall and the smoke outlet shell has a smoke outlet on one side. High-temperature smoke enters from the smoke inlet and is discharged from the smoke outlet. The shell includes a high-temperature smoke zone and a low-temperature smoke zone, which are distributed sequentially along the smoke flow direction. First heat transfer tube: The first heat transfer tube is disposed inside the shell and located in the high-temperature flue gas zone. A first liquid inlet is provided on one side of the shell, and the input end of the first heat transfer tube is inserted into the first liquid inlet. Second heat transfer tube: The input end of the second heat transfer tube is connected to the output end of the first heat transfer tube. The first heat transfer tube is located in the low-temperature flue gas zone. A second liquid outlet is opened on one side of the shell. The output end of the second heat transfer tube is inserted into the second liquid outlet. Medium: The medium enters the cavity of the first heat transfer tube from the first liquid inlet, and the temperature difference between the flue gas entering the input end of the high-temperature flue gas zone and the medium entering the input end of the first heat transfer tube is controlled at 60℃-90℃.

2. The high and low temperature flue gas energy saver as described in claim 1, characterized in that, A second temperature sensor is installed at the output end of the first heat transfer tube.

3. The high and low temperature flue gas energy saver as described in claim 1, characterized in that, The output end of the first heat transfer tube and the input end of the second heat transfer tube extend outside the housing.

4. The high and low temperature flue gas energy saver as described in claim 2, characterized in that, The medium is water flow. The output end of the second heat transfer tube is connected to an output pipe. The output end of the output pipe is connected to a soft water tank. The other input end of the soft water tank is connected to a water softener. The water softener provides cold water to the soft water tank. The hot water flowing out from one output end of the soft water tank is supplied to a boiler or other equipment that requires heat energy.

5. The high and low temperature flue gas energy saver as described in claim 4, characterized in that, The other output end of the soft water tank is connected to a water supply pipe, and the end of the water supply pipe away from the soft water tank is connected to the input end of the first heat transfer pipe.

6. The high and low temperature flue gas energy saver as described in claim 5, characterized in that, The output end of the output pipe is connected to an electric three-way valve. One opening of the electric three-way valve is connected to an input pipe. The end of the input pipe away from the electric three-way valve is connected to an input end of the soft water tank. A mixing device is connected to the water supply pipe. The other opening of the electric three-way valve is connected to a neutralization pipe. The end of the neutralization pipe away from the electric three-way valve is connected to an input end of the mixing device.

7. The high and low temperature flue gas energy saver as described in claim 6, characterized in that, A first thermometer is connected to the water supply pipe. The first thermometer is located at the output end of the mixer and is used to measure the temperature of the water flowing out of the output end of the mixer.

8. The high and low temperature flue gas energy saver as described in claim 7, characterized in that, A circulating pump set is installed on the water supply pipe. The water mixer, the first thermometer and the circulating pump set are arranged in sequence along the direction of water flow. The circulating pump set is used to regulate the flow rate of the water in circulation.

9. The high and low temperature flue gas energy saver as described in claim 8, characterized in that, The circulating pump set includes a main circulating pump and a standby circulating pump. The main circulating pump is connected to the water supply pipe and is used to regulate the flow rate of the water supplied to the energy-saving device by the water supply pipe. The standby circulating pump is connected in parallel with the main circulating pump.

10. The high and low temperature flue gas energy saver as described in claim 9, characterized in that, The first heat transfer tube and the second heat transfer tube are made of carbon steel.

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