Efficient and energy-saving steam boiler system and using method

Abstract

The invention discloses an efficient and energy-saving steam boiler system and a using method, and belongs to the technical field of boilers, the efficient and energy-saving steam boiler system comprises a boiler body, a hearth, a smoke pipe and a burner, an exhaust pipe is arranged at an outlet of the smoke pipe, the exhaust pipe is provided with a heat exchanger, a first heat exchanger and a second heat exchanger, and an air inlet of the burner is communicated with the heat exchanger; the steam boiler system further comprises a water storage tank, the water storage tank is communicated with an inlet and an outlet of the first heat exchanger through a first pipeline, and the water storage tank is communicated with an inlet of the second heat exchanger through a second pipeline. The heat exchanger, the first heat exchanger and the second heat exchanger are used for recovering heat of flue gas in sequence, step-by-step cooling and heat extraction are carried out on the high-temperature flue gas, the recovered heat is used for heating air entering the combustor, water in the water storage tank and water conveyed to the boiler body by the water storage tank, energy consumption of the steam boiler is reduced, and energy conservation and emission reduction are achieved. And the energy-saving performance of the whole equipment is improved.

Description

Technical Field

[0001] This invention relates to the field of boilers, and more specifically to a high-efficiency and energy-saving steam boiler system and its usage method. Background Technology

[0002] In existing steam boiler systems, the high-temperature flue gas generated after fuel combustion, after completing radiative heat exchange and convective heat transfer in the furnace, still carries a large amount of waste heat and is discharged into the atmosphere through the chimney. The temperature of this discharged flue gas is usually between 150°C and 250°C, or even higher. Direct discharge not only leads to a large waste of heat energy but also significantly reduces the overall thermal efficiency of the boiler. Usually, flue gas is used for preheating with feedwater or combustion air. However, the recovery method is relatively simple and fails to fully utilize the waste heat in the flue gas, resulting in resource waste. Summary of the Invention

[0003] The purpose of this invention is to provide a high-efficiency and energy-saving steam boiler system and its usage method, which solves the problem that the existing recovery methods are relatively simple and fail to make full use of the waste heat in the flue gas, resulting in resource waste.

[0004] The present invention achieves the above objectives through the following technical solution: a high-efficiency and energy-saving steam boiler system, comprising: a furnace body, a furnace chamber, a flue pipe and a burner, wherein the outlet of the flue pipe is provided with an exhaust pipe, and the exhaust pipe is provided with a heat exchanger, a first heat exchanger and a second heat exchanger in sequence along the flue gas flow direction; The air inlet of the burner is connected to the heat exchanger; The steam boiler system also includes a water storage tank, which is connected to the inlet and outlet of the first heat exchanger via a first pipe, and to the inlet of the second heat exchanger via a second pipe. The outlet of the second heat exchanger is connected to the boiler body via a third pipe.

[0005] Preferably, the exhaust pipe is provided with a third heat exchanger, which is located downstream of the second heat exchanger, and the third heat exchanger is connected to a heat pump assembly through a circulation pipe.

[0006] Preferably, the steam boiler system further includes a controller, a temperature sensor is provided on the water storage tank, and a third solenoid valve and a third delivery pump are provided on the circulation pipe of the third heat exchanger. The controller is used to control the third solenoid valve and the third delivery pump to start when the water temperature inside the water storage tank is greater than a preset value.

[0007] Preferably, the first pipeline is equipped with a first solenoid valve and a first delivery pump, and the controller is used to control the first solenoid valve and the first delivery pump to close when the water temperature inside the water storage tank is greater than a preset value.

[0008] Preferably, the second pipeline is equipped with a second solenoid valve and a second delivery pump, which are used to start when the water level inside the furnace is lower than a threshold.

[0009] Preferably, the first heat exchanger, the second heat exchanger, and the third heat exchanger each include a shell, a conduit disposed on the shell, a heat exchange tube disposed inside the shell, a main pipe connecting the two ends of the heat exchange tube, and a delivery pipe connecting the main pipe.

[0010] Preferably, there are several heat exchange tubes, which are divided into inner and outer rings. The connection area between the main pipe and the heat exchange tubes is provided with an opening. The main pipe connected to the inlet end of the heat exchange tubes is provided with several arc-shaped blocks and elastic elements connected to the arc-shaped blocks. The several arc-shaped blocks form a ring to separate the openings on the inner and outer sides.

[0011] Preferably, the furnace chamber is provided with a movable plate that moves along the direction of water level rise and fall in the furnace body, and the furnace body is provided with a driving component for moving the movable plate.

[0012] Preferably, a method for using a high-efficiency and energy-saving steam boiler system, utilizing the aforementioned high-efficiency and energy-saving steam boiler system, includes the following steps: S1: The burner burns, supplying high-temperature flue gas into the furnace. The high-temperature flue gas enters the flue pipe and heats the water inside the furnace, causing the water to evaporate and generate steam. S2: The flue gas after heat exchange enters the exhaust pipe from the flue pipe and passes through the heat exchanger, the first heat exchanger and the second heat exchanger in sequence to recover heat. The recovered heat is used to heat the air entering the burner, the water inside the water tank and the water supplied from the water tank to the furnace body.

[0013] The beneficial effects of this invention are as follows: 1. The heat of the flue gas is recovered sequentially through the heat exchanger, the first heat exchanger and the second heat exchanger. The high-temperature flue gas is cooled down and the heat is extracted in stages. The recovered heat is used to heat the air entering the burner, the water in the water tank and the water transported from the water tank to the furnace, thereby reducing the energy consumption of the steam boiler, avoiding energy waste and increasing the overall energy efficiency of the equipment. 2. When the water temperature inside the storage tank is higher than the preset value, the controller controls the third solenoid valve and the third delivery pump to start, inputting the heat exchange medium into the third heat exchanger to exchange heat with the flue gas inside the exhaust pipe, absorbing the heat of the flue gas, and using the heat of the heat exchange medium to produce a high-grade heat source. This avoids the problem of the flue gas heat not being effectively transferred due to the upstream heat exchanger being close to thermal equilibrium, and ensures that the flue gas heat can be continuously and fully captured and utilized under various operating conditions. Attached Figure Description

[0014] Figure 1This is a schematic diagram of the steam boiler system structure of the present invention; Figure 2 This is a schematic diagram of the connection structure between the third heat exchanger and the heat pump assembly of the present invention; Figure 3 For the present invention Figure 1 Enlarged schematic diagram of the structure at point A in the middle; Figure 4 This is a schematic diagram of the structure of the second heat exchanger of the present invention; Figure 5 This is a schematic diagram of the connection structure between the main pipe and the heat exchanger pipe of the present invention.

[0015] In the diagram: 1. Furnace body; 2. Furnace chamber; 3. Smoke pipe; 4. Burner; 5. Exhaust pipe; 6. Heat exchanger; 7. First heat exchanger; 8. Second heat exchanger; 801. Shell; 802. Pipe; 803. Main pipe; 804. Heat exchange tube; 805. Delivery pipe; 806. Opening; 807. Arc block; 808. Elastic element; 9. Third heat exchanger; 10. Water storage tank; 11. Temperature sensor; 12. Controller; 13. Heat pump assembly; 14. First solenoid valve; 15. First delivery pump; 16. Second solenoid valve; 17. Second delivery pump; 18. Third solenoid valve; 19. Third delivery pump; 20. Drive component; 21. Moving plate. Detailed Implementation

[0016] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0017] Example 1 Please see Figure 1 A high-efficiency and energy-saving steam boiler system includes: a furnace body 1, a furnace chamber 2, a flue pipe 3 and a burner 4. The furnace chamber 2 is installed in the inner cavity of the furnace body 1. There are multiple flue pipes 3 and they are connected to the furnace chamber 2. The burner 4 is installed on the outside of the furnace body 1 and is connected to the furnace chamber 2. An exhaust pipe 5 is connected to the outlet end of the flue pipe 3.

[0018] It should be noted that a steam valve or gas-liquid separator is installed on the top of the furnace body 1 to discharge the steam generated inside the furnace body 1; a level gauge is installed on the furnace body 1 to detect the water level inside the furnace body 1.

[0019] Please see Figure 1 and Figure 2The exhaust pipe 5 is provided with a heat exchanger 6, a first heat exchanger 7 and a second heat exchanger 8 in sequence along the flue gas flow direction; the air inlet of the burner 4 is connected to the shell side of the heat exchanger 6, and the exhaust pipe 5 is connected to the tube side of the heat exchanger 6; the steam boiler system also includes a water storage tank 10, which is connected to the inlet and outlet of the first heat exchanger 7 through a first pipe, the water storage tank 10 is connected to the inlet of the second heat exchanger 8 through a second pipe, and the outlet of the second heat exchanger 8 is connected to the furnace body 1 through a third pipe.

[0020] A method for using a high-efficiency and energy-saving steam boiler system, including the following specific steps: First, the burner 4 burns, providing high-temperature flue gas into the furnace 2. The high-temperature flue gas enters the flue pipe 3 and exchanges heat with the water inside the furnace 1, thereby heating the water to evaporate and generate steam. Secondly, the flue gas after heat exchange is discharged from the flue pipe 3 and enters the exhaust pipe 5, and then passes through the heat exchanger 6, the first heat exchanger 7 and the second heat exchanger 8 in sequence to recover heat. Outside air enters the heat exchanger 6 to absorb the heat of the flue gas, and then enters the burner 4 to preheat the air used by the burner 4, improve the combustion temperature and efficiency, make full use of fuel, and save energy. The water in the water tank 10 enters the first heat exchanger 7 to absorb the heat of the flue gas and raise its own temperature. When water is added to the furnace body 1, the water absorbs heat through the second heat exchanger 8, raises its own temperature and then enters the interior of the furnace body 1, so that the heat required by the steam boiler is reduced accordingly, thereby reducing fuel consumption and achieving energy saving.

[0021] In this embodiment, as a further optimization, please refer to... Figure 1 and Figure 2 The exhaust pipe 5 is equipped with a third heat exchanger 9, which is located downstream of the second heat exchanger 8. The third heat exchanger 9 is connected to a heat pump assembly 13 via a circulation pipe. The steam boiler system also includes a controller 12 (such as an ECU). A temperature sensor 11 is installed on the water storage tank 10 to detect the temperature of the water inside the water storage tank 10. A third solenoid valve 18 and a third delivery pump 19 are installed on the circulation pipe of the third heat exchanger 9. The temperature sensor 11 acquires the water temperature inside the water storage tank 10 in real time and transmits it to the controller 12. When the water temperature is higher than a preset value, the controller 12... 2. Control the third solenoid valve 18 and the third delivery pump 19 to start, and input the heat exchange medium into the third heat exchanger 9 for heat exchange with the flue gas inside the exhaust pipe 5, absorbing the heat in the flue gas. After the heat exchange medium is heated, it enters the heat pump assembly 13, and uses the heat of the heat exchange medium to produce a high-grade heat source. This avoids the direct discharge of a large amount of heat contained in the flue gas due to the decrease in the heat exchange capacity of the first heat exchanger 7 and the second heat exchanger 8 (the water in the water storage tank 10 will heat up as heat exchange continues, causing the heat exchange capacity of the water to gradually decrease), ensuring that the heat in the flue gas is fully utilized.

[0022] In this embodiment, as a further optimization, please refer to... Figure 1 and Figure 2 The first pipeline is equipped with a first solenoid valve 14 and a first delivery pump 15. When the water temperature inside the water storage tank 10 is greater than the preset value, the controller 12 controls the first solenoid valve 14 and the first delivery pump 15 to close, so that the water inside the water storage tank 10 stops entering the first heat exchanger 7, which has the effect of saving energy (because the water in the water storage tank 10 can no longer absorb the heat of the flue gas or absorbs a low amount of heat).

[0023] It should be noted that when the water temperature inside the water storage tank 10 is lower than the preset value, the controller 12 controls the first solenoid valve 14 and the first delivery pump 15 to start, so that the water in the water storage tank 10 continues to circulate in the first heat exchanger 7; during the above process, the controller 12 controls the third solenoid valve 18 and the third delivery pump 19 to close, so that the third heat exchanger 9 and the heat pump assembly 13 stop working.

[0024] In this embodiment, as a further optimization, please refer to... Figure 1 The second pipeline is equipped with a second solenoid valve 16 and a second delivery pump 17. The second solenoid valve 16 and the second delivery pump 17 are used to start when the water level inside the furnace body 1 is lower than the threshold, and to deliver water from the water storage tank 10 to the furnace body 1 until the water level inside the furnace body 1 is higher than the set value. Then the controller 12 controls the second solenoid valve 16 and the second delivery pump 17 to close.

[0025] Example 2 As a further optimization of Example 1, please refer to Figure 1 and Figure 4 The first heat exchanger 7, the second heat exchanger 8, and the third heat exchanger 9 each include a shell 801, two conduits 802 connected to the outer wall of the shell 801, a heat exchange tube 804 located in the inner cavity of the shell 801, two main pipes 803 connected to both ends of the heat exchange tube 804, and a delivery pipe 805 connected to the main pipe 803. The delivery pipes 805 of the first heat exchanger 7, the second heat exchanger 8, and the third heat exchanger 9 are all connected to the exhaust pipe 5. The conduit 802 of the first heat exchanger 7 is connected to the first pipe, the conduit 802 of the second heat exchanger 8 is connected to the second pipe and the third pipe, and the conduit 802 of the third heat exchanger 9 is connected to the circulation pipe.

[0026] In this embodiment, as a further optimization, please refer to... Figure 4 and Figure 5There are several heat exchange tubes 804, which are divided into inner and outer rings. An opening 806 is provided at the connection area between the main pipe 803 and the heat exchange tubes 804. Several arc-shaped blocks 807 are slidably arranged in the inner cavity of the main pipe 803, which is connected to the inlet end of the heat exchange tubes 804. An elastic element 808 (such as a spring) is provided between the main pipe 803 and the arc-shaped blocks 807. The several arc-shaped blocks 807 form a ring, separating the inner and outer openings 806. When the flue gas flowing in the exhaust pipe 5 enters the inner cavity of the main pipe 803 through the conveying pipe 805, if the amount of flue gas is small, the flue gas cannot be pushed. The arc-shaped blocks 807 move, placing the flue gas within the ring formed by the arc-shaped blocks 807, and then entering the inner ring heat exchange tube 804. If the flue gas volume is large, the pressure of the flue gas acts on the arc-shaped blocks 807, pushing them to move and creating gaps between the arc-shaped blocks 807, allowing the flue gas to pass through. At this time, the flue gas can enter both the inner and outer ring heat exchange tubes 804, reducing the flow rate of the flue gas inside the heat exchange tubes 804 and ensuring that the residence time of the flue gas in the heat exchange tubes 804 is increased, thereby allowing the heat in the flue gas to be fully absorbed.

[0027] Example 3 As a further optimization of Example 1, please refer to Figure 1 and Figure 3 A movable plate 21 is slidably installed in the inner cavity of the furnace chamber 2. The movable plate 21 moves along the direction of water level rise and fall in the furnace body 1 (i.e., moves up and down). A driving component 20 (such as a hydraulic cylinder) is provided on the outer side of the furnace body 1. The moving end of the driving component 20 is connected to the movable plate 21 through a guide rod. When the controller 12 detects that the water level inside the furnace body 1 has dropped significantly, exposing part of the flue pipe 3, the controller 12 controls the driving component 20 to start, driving the movable plate 21 to move down. This is used to block the flue gas inside the furnace chamber 2 from entering the flue pipe 3 located outside the water, preventing the flue gas from entering the flue pipe 3 in this area and failing to exchange heat with the water sufficiently. This ensures that the heat in the flue gas can be fully utilized, achieving an energy-saving effect.

[0028] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A high-efficiency and energy-saving steam boiler system, comprising: The furnace body (1), furnace chamber (2), flue pipe (3) and burner (4) are characterized in that the outlet of the flue pipe (3) is provided with an exhaust pipe (5), and the exhaust pipe (5) is provided with a heat exchanger (6), a first heat exchanger (7) and a second heat exchanger (8) in sequence along the flue gas flow direction. The air inlet of the burner (4) is connected to the heat exchanger (6); The steam boiler system also includes a water storage tank (10), which is connected to the inlet and outlet of the first heat exchanger (7) through a first pipe, and the water storage tank (10) is connected to the inlet of the second heat exchanger (8) through a second pipe. The outlet of the second heat exchanger (8) is connected to the furnace body (1) through a third pipe.

2. The high-efficiency and energy-saving steam boiler system according to claim 1, characterized in that, The exhaust pipe (5) is provided with a third heat exchanger (9), which is located downstream of the second heat exchanger (8). The third heat exchanger (9) is connected to a heat pump assembly (13) through a circulation pipe.

3. The high-efficiency and energy-saving steam boiler system according to claim 2, characterized in that, The steam boiler system also includes a controller (12), a temperature sensor (11) is provided on the water storage tank (10), and a third solenoid valve (18) and a third delivery pump (19) are provided on the circulation pipe of the third heat exchanger (9). The controller (12) is used to control the third solenoid valve (18) and the third delivery pump (19) to start when the water temperature inside the water storage tank (10) is greater than a preset value.

4. The high-efficiency and energy-saving steam boiler system according to claim 3, characterized in that, The first pipeline is equipped with a first solenoid valve (14) and a first delivery pump (15). The controller (12) is used to control the first solenoid valve (14) and the first delivery pump (15) to close when the water temperature inside the water storage tank (10) is greater than a preset value.

5. The high-efficiency and energy-saving steam boiler system according to claim 1, characterized in that, The second pipeline is equipped with a second solenoid valve (16) and a second delivery pump (17), which are used to start when the water level inside the furnace body (1) is lower than the threshold.

6. The high-efficiency and energy-saving steam boiler system according to claim 2, characterized in that, The first heat exchanger (7), the second heat exchanger (8) and the third heat exchanger (9) each include a shell (801), a conduit (802) provided on the shell (801), a heat exchange tube (804) provided in the shell (801), a main pipe (803) connecting the two ends of the heat exchange tube (804) and a delivery pipe (805) connecting the main pipe (803).

7. A high-efficiency and energy-saving steam boiler system according to claim 6, characterized in that, There are several heat exchange tubes (804), and the heat exchange tubes (804) are divided into inner and outer rings. The connection area between the main pipe (803) and the heat exchange tubes (804) is provided with an opening (806). The main pipe (803) connected to the inlet end of the heat exchange tubes (804) is provided with several arc-shaped blocks (807) and elastic members (808) connected to the arc-shaped blocks (807). The several arc-shaped blocks (807) form a ring to separate the openings (806) on the inner and outer sides.

8. The high-efficiency and energy-saving steam boiler system according to claim 1, characterized in that, The furnace chamber (2) is provided with a movable plate (21) that moves along the direction of water level rise and fall of the furnace body (1), and the furnace body (1) is provided with a driving component (20) for driving the movable plate (21) to move.

9. A method of using a high-efficiency and energy-saving steam boiler system, comprising the high-efficiency and energy-saving steam boiler system as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: The burner (4) burns and provides high-temperature flue gas into the furnace (2). The high-temperature flue gas enters the flue pipe (3) and heats the water inside the furnace body (1) so that the water evaporates and produces steam. S2: The flue gas after heat exchange enters the exhaust pipe (5) from the flue pipe (3) and is successively passed through the heat exchanger (6), the first heat exchanger (7) and the second heat exchanger (8) to recover heat. The recovered heat is used to heat the air entering the burner (4), the water inside the water tank (10) and the water transported from the water tank (10) to the furnace body (1).

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