Micro-hearth steam generation device and steam generation method

Abstract

The problems that an existing steam generating device is low in steam dryness and high in energy consumption are solved. The invention provides a micro-hearth steam generation device and a steam generation method. The micro-hearth steam generation device comprises a steam-water separator, a ventilation chamber and a combustion chamber, the combustion chamber is communicated with the ventilation chamber; a first heating structure is further arranged in the combustion chamber and used for water flow to flow through. The steam-water separator is connected with the first heating structure and is used for separating liquid water and high-temperature steam; a second heating structure is arranged in the energy saver, and the second heating structure is connected with the end, away from the steam-water separator, of the first heating structure. The cavity in the energy saver is also communicated with the combustion chamber; the energy saver is also provided with a chimney for discharging flue gas; the water flow direction is opposite to the flue gas flowing direction, so that the water flow can be fully heated to form overheated water vapor.

Description

Technical Field

[0001] The present invention relates to the technical field of steam generators, and in particular to a micro-furnace steam generating device and a steam generating method. Background Art

[0002] A steam generator is a device that uses external energy to heat water and convert it into steam, where the external energy is usually natural gas. As a product to replace traditional boilers, steam generators have advantages over traditional boilers, such as small size, fast gas production speed, and simple installation / use procedures, such as the contents shown in the patents with authorization announcement numbers CN212481237U and CN105066657B. However, due to the unreasonable structural design of the furnace, heating surface and other structures in the existing steam generators, a large number of products on the market currently have problems such as low steam dryness and high energy consumption. Some other products even have an actual water volume of more than 30L, which not only does not meet the requirements of the new version of the boiler regulations for exemption from supervision and inspection, but also poses a great safety hazard. Therefore, a steam generator with high volumetric heat load, high heat transfer efficiency and small water volume is needed. Summary of the invention

[0003] The object of the present invention is to solve the deficiencies of the prior art and to provide a micro-furnace steam generating device and a steam generating method.

[0004] In order to solve the above problems, the present invention adopts the following technical solutions: A micro-furnace steam generating device comprises a steam-water separator, a ventilation chamber and a combustion chamber; wherein the combustion chamber is connected to the ventilation chamber so that the combustible gas introduced into the ventilation chamber can enter the combustion chamber for combustion; a first heating structure is also arranged in the combustion chamber, and the first heating structure is used for flowing water; the steam-water separator is connected to the first heating structure for separating liquid water and high-temperature steam; an economizer is also included, a second heating structure is arranged in the economizer, and the second heating structure is connected to an end of the first heating structure away from the steam-water separator; the cavity inside the economizer is also connected to the combustion chamber so that the high-temperature flue gas can pass through the combustion chamber and the economizer in sequence; the economizer is also provided with a chimney for exhausting the flue gas; The ventilation chamber includes a gas inlet, a combustion-supporting air inlet, a mixing chamber and a cooling structure; the mixing chamber as a whole is a tubular structure with a hollow interior; one end of the mixing chamber is connected to the combustion chamber, and the other end of the mixing chamber is provided with a combustion-supporting air inlet; a gas inlet is also provided on the side of the mixing chamber; a cooling structure for preventing heat backflow is also provided between the mixing chamber and the combustion chamber; the cooling structure is also connected to the second heating structure, so that the cooling and heat-absorbing liquid flows into the second heating structure for heating.

[0005] Furthermore, a hot water tank and a water pump are arranged between the second heating structure and the first heating structure; the hot water tank is used to store liquid heated by the second heating structure; and the water pump is arranged between the hot water tank and the first heating structure.

[0006] Furthermore, the cooling structure includes a cooling water header and a water-cooling pipe structure distributed in a labyrinth manner; the cooling water header includes an inlet header and an outlet header respectively arranged at both ends of the water-cooling pipe structure; the water-cooling pipe structure is located between the mixing chamber and the combustion chamber.

[0007] Furthermore, the water-cooling pipe structure includes a plurality of water-cooling pipes arranged in parallel and at equal intervals; the cross-section of the water-cooling pipe is Z-shaped, and different water-cooling pipes are located in the same horizontal plane.

[0008] Furthermore, a high emissivity coating is provided on one side of the water cooling tube close to the combustion chamber.

[0009] Furthermore, a diversion structure is arranged between the mixing chamber and the cooling structure; the diversion structure includes a trumpet-shaped diversion shell and a diversion plate; wherein the side with a larger opening in the diversion shell is connected to the cooling structure, and the side with a smaller opening is connected to the mixing chamber; and a plurality of diversion plates are arranged between the diversion shells.

[0010] Furthermore, the first heating structure includes a radiation heating zone and a convection heating surface; the radiation heating zone and the convection heating surface are arranged in sequence from top to bottom in the combustion chamber; the radiation heating zone is the location where the gas burns; the radiation heating zone is connected to the convection heating surface; the convection heating surface includes a plurality of fin tubes, two rows of fin tubes form a group, and the convection heating surface includes 3 to 4 groups of fin tubes; the fin tubes in the same row of fin tubes are distributed from top to bottom, the upstream and downstream spacing of adjacent fin tubes is 80 mm, and the spacing between adjacent fin tubes in the same group of fin tubes is 50 mm.

[0011] Furthermore, the cross section of the fin tube is H-shaped; the thickness of the fin tube is 2 mm, and the distance between adjacent fins in the fin tube is 4 mm.

[0012] A steam generation method, based on the above steam generation device, the steam generation method comprises the following steps: Step 1: Water flows into the water cooling pipe structure, absorbs heat in the water cooling pipe and then enters the second heating structure; Step 2: The flue gas after cooling around the second heating structure heats the water flow in the second heating structure, and then the water flow heated to 60°C~70°C enters the hot water tank; Step 3: The water in the hot water tank is pumped to the first heating structure by a water pump. The water flows through the convection heating surface and the periphery of the radiation heating area of ​​the first heating structure, and finally forms water vapor to be transported outward.

[0013] The beneficial effects of the present invention are: By setting the first heating structure and the second heating structure, the water flow direction is opposite to the flue gas flow direction, so that the water flow can be fully heated to form superheated water vapor; By setting up a cooling structure, on the one hand, the flashback problem can be avoided and safety can be improved; on the other hand, with the high emissivity coating, the water flow can be preliminarily heated to improve the heat transfer efficiency; By arranging the radiation heating zone in conjunction with the convection heating surface, the flame and high-temperature flue gas generated by the combustion in the radiation heating zone can directly flush the convection heating surface. Combined with the high-density finned tubes in the convection heating surface, the dryness of the steam can be greatly improved under the premise of low water volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural connection block diagram of Example 1; Figure 2 It is a schematic diagram of the overall structure of Example 1; Figure 3 Schematic diagram of the ventilation chamber of Example 1; Figure 4 is a cross-sectional view of the ventilation chamber of Example 1; Figure 5 This is a schematic diagram of the coordination between the first heating structure and the steam-water separator of Example 1; Explanation of the accompanying drawings: 1 ventilation chamber, 2 radiation heating zone, 3 steam-water distribution pipe, 4 convection heating surface, 5 steam-water separator, 6 economizer, 7 chimney, 1-1 gas inlet, 1-2 combustion-supporting air inlet, 1-3 mixing chamber, 1-4 guide plate, 1-5 cooling water header, 1-6 water-cooling pipe structure, 1-7 high emissivity coating, 1-51 inlet end header, 1-52 outlet end header, 1-53 cooling water inlet and outlet, 2-1 steam header, 4-1 fin tube. DETAILED DESCRIPTION

[0015] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0016] It should be noted that the illustrations provided in the following embodiments are only used to schematically illustrate the basic concept of the present invention. The figures only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated. Example

[0017] A micro-furnace steam generating device comprises a steam-water separator 5, a ventilation chamber 1 and a combustion chamber; wherein the combustion chamber is connected to the ventilation chamber 1 so that the combustible gas introduced into the ventilation chamber 1 can enter the combustion chamber for combustion; a first heating structure is also provided in the combustion chamber, and the first heating structure is used for flowing water. The water flowing through the first heating structure will contact with the high-temperature flue gas generated after combustion in the combustion chamber, absorb heat, and generate a large amount of water vapor after the water flow is heated; the steam-water separator 5 is connected to the first heating structure, and is used to separate the combustible gas after passing through the first heating structure. liquid water and high-temperature steam; also includes an economizer 6, in which a second heating structure is provided, and the second heating structure is connected to the end of the first heating structure away from the steam-water separator 5; the cavity inside the economizer 6 is also connected to the combustion chamber, so that the high-temperature flue gas can pass through the combustion chamber and the economizer 6 in sequence, wherein the temperature of the flue gas entering the economizer 6 is approximately between 200°C and 250°C, and after heat exchange with the second heating structure, the temperature of the flue gas flowing out is approximately between 50°C and 70°C; the economizer 6 is also provided with a chimney 7 for discharging the flue gas.

[0018] The ventilation chamber 1 includes a gas inlet 1-1, a combustion-supporting air inlet 1-2, a mixing chamber 1-3 and a cooling structure; the mixing chamber 1-3 is a tubular structure with a hollow interior as a whole; one end of the mixing chamber 1-3 is connected to the combustion chamber, and the other end of the mixing chamber 1-3 is provided with a combustion-supporting air inlet 1-2, and the combustion-supporting air inlet 1-2 is also provided with a fan for helping external air to flow into the mixing chamber 1-3; a gas inlet 1-1 is also provided on the side of the mixing chamber 1-3; a cooling structure for preventing heat backflow is also provided between the mixing chamber 1-3 and the combustion chamber; the cooling structure is also connected to the second heating structure, so that the cooling and heat-absorbing liquid flows into the second heating structure for further heating. The cooling structure includes a cooling water header 1-5 and a water-cooling pipe structure 1-6 distributed in a labyrinth manner; in this example, the cooling water header 1-5 includes an inlet header 1-51 and an outlet header 1-52 respectively arranged at both ends of the water-cooling pipe structure 1-6; wherein the inlet header 1-51 and the outlet header 1-52 are respectively provided with a plurality of cooling water inlets and outlets 1-53, so that water flows into the inlet header 1-51 in multiple streams and flows out of the outlet header 1-52 in multiple streams; the water-cooling pipe structure 1-6 is located between the mixing chamber 1-3 and the combustion chamber. The water-cooling pipe structure 1-6 includes a plurality of water-cooling pipes arranged in parallel and at equal intervals; in this example, the cross-section of the water-cooling pipe is Z-shaped, and different water-cooling pipes are located on the same horizontal plane. A high-emissivity coating 1-7 is also provided on one side of the water-cooling pipe close to the combustion chamber to help the water-cooling pipe absorb the heat dissipated from the combustion chamber to the water-cooling pipe area, thereby preventing this part of the heat from affecting the gas in the ventilation chamber 1, and also preventing the flame from burning in the combustion chamber from flowing back, thereby improving safety; in this example, the thickness of the high-emissivity coating 1-7 is 50μm~80μm, and the emissivity is 0.9.

[0019] A diverter structure is also provided between the mixing chamber 1-3 and the cooling structure; the diverter structure includes a trumpet-shaped diverter shell and a diverter plate; wherein the side with a larger opening in the diverter shell is connected to the cooling structure, and the side with a smaller opening is connected to the mixing chamber 1-3; a number of diverter plates are provided between the diverter shells. It should be noted that in this example, the mixing chamber 1-3 is arranged above the combustion chamber in a horizontal state as a whole, and the diverter structure is located in a vertical direction, so a 90° elbow for connection is also provided between the mixing chamber 1-3 and the diverter structure. Through the diverter structure, the mixed gas in the mixing chamber 1-3 flows evenly into the combustion chamber.

[0020] A hot water tank and a water pump are also provided between the second heating structure and the first heating structure; the hot water tank is used to store the liquid preliminarily heated by the second heating structure; the water pump is provided between the hot water tank and the first heating structure, and is used to pump the liquid in the hot water tank into the first heating structure. The hot water tank and the water pump are provided outside the combustion chamber and the economizer 6.

[0021] The first heating structure includes a radiation heating zone 2 and a convection heating surface 4; wherein the radiation heating zone 2 and the convection heating surface 4 are arranged in sequence from top to bottom in the combustion chamber, and the radiation heating zone 2 is arranged close to the cooling structure; the radiation heating zone 2 is the main part of the gas combustion heat exchange; the radiation heating zone 2 is connected to the convection heating surface 4; the convection heating surface 4 includes a plurality of fin tubes 4-1, two rows of fin tubes 4-1 form a group, and the convection heating surface 4 includes 3 to 4 groups of fin tubes 4-1; the fin tubes 4-1 in the same row of fin tubes 4-1 are distributed from top to bottom, and the upstream and downstream spacing of adjacent fin tubes 4-1 is 80mm, and the spacing between adjacent fin tubes 4-1 in the same group of fin tubes 4-1 is 50mm. The cross section of the fin tube 4-1 is H-shaped; the thickness of the fin tube 4-1 is 2mm, and the spacing between adjacent fins in the fin tube 4-1 is 4mm. The outlet of each row of finned tubes 4-1 is also provided with a thermocouple for detecting the tube wall temperature; it should be noted that the thermocouple is used to detect the tube wall temperature flowing out of the finned tube 4-1. In this example, if the tube wall temperature exceeds the set value range, it needs to be adjusted in conjunction with the water pump to achieve a relatively stable temperature of the liquid flowing through the finned tube 4-1. It should be noted that in this example, the high-temperature flue gas directly flushes the radiation heating area and the convection heating surface in the combustion chamber, so that the contact area between the flue gas and the steam header on the side of the finned tube or the radiation heating area 2 is large, so that the water flow therein can be fully heated and quickly converted into water vapor.

[0022] The radiation heating zone 2 includes a rectangular furnace and steam headers 2-1 distributed around the furnace; in this example, the height of the furnace is 100mm~200mm; the furnace as a whole adopts high-strength corundum refractory castable, and the thickness of the furnace is 100mm. In this example, the steam-water separator 5 is arranged between the steam header 2-1 and the convection heating surface 4 around the radiation heating zone 2. A steam-water distribution pipe 3 is also arranged between the steam-water separator 5 and the convection heating surface 4, and the steam-water distribution pipe 3 includes multiple inlets, which correspond to multiple groups of fin tubes 4-1 respectively, and the steam-water distribution pipe 3 also includes an outlet, which is connected to the steam-water separator 5. The use of a furnace with a lower height reduces the residence time of the flue gas in the furnace on the one hand, so that the gas flame burning in the furnace can directly flush the convection heating surface 4 below the furnace, and the convection heating surface 4 absorbs the heat contained in the flame and the flue gas, so as to realize the heating and temperature raising process of the water flow flowing between the convection heating surfaces 4.

[0023] The bottom of the combustion chamber is connected to the top of the economizer 6, and a partition is also provided inside the economizer 6. A gap is left between the partition and the bottom side of the economizer 6 for the circulation of flue gas. The connecting part between the combustion chamber and the economizer 6 and the chimney 7 in the economizer 6 are respectively located on both sides of the partition, so that the flue gas entering the economizer 6 can flow over a longer distance, fully complete the heat exchange with the second heating structure in the economizer 6, and then flow out from the chimney 7.

[0024] After actual measurement, in this example, the total water storage capacity of the cooling structure, the first heating structure, the second heating structure and the hot water tank is 25.2L, and the actual water vapor evaporation capacity is 1t / h.

[0025] A steam generation method, based on the above steam generation device, the steam generation method comprises the following steps: Step 1: water flows into the water cooling pipe structure 1-6, absorbs heat in the water cooling pipe and then enters the second heating structure; Step 2: The flue gas after cooling around the second heating structure heats the water flow in the second heating structure, and then the water flow heated to 60°C~70°C enters the hot water tank; Step 3: The water in the hot water tank is pumped to the first heating structure by a water pump. The water flows through the convection heating surface 4 and the periphery of the radiation heating area 2 of the first heating structure, and finally forms water vapor to be transported outward.

[0026] During the implementation process, by setting the first heating structure and the second heating structure, the water flow direction is opposite to the flue gas flow direction, so that the water flow can be fully heated to form superheated steam; by setting the radiation heating zone 2 in conjunction with the convection heating surface 4, the flame and high-temperature flue gas generated by the combustion in the radiation heating zone 2 can directly flush the convection heating surface 4, and cooperate with the high-density fin tubes 4-1 in the convection heating surface 4, so that the dryness of the steam is greatly improved under the premise of low water volume; by setting the water-cooling tube structure 1-6, traditional premixed combustion, on the one hand, avoids the problem of flashback and improves safety, and reduces the oxygen content under the premise of ensuring that the nitrogen oxide emissions are lower than 30mg / Nm3; on the other hand, in conjunction with the high-emissivity coating 1-7, the water flow is preliminarily heated to improve the heat transfer efficiency.

[0027] The above description is only a specific example of the present invention and does not constitute any limitation to the present invention. It is obvious that for professionals in this field, after understanding the content and principle of the present invention, various modifications and changes in form and details may be made without departing from the principle and structure of the present invention, but these modifications and changes based on the idea of ​​the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A micro-furnace steam generating device, comprising a steam-water separator (5), a ventilation chamber (1) and a combustion chamber; wherein: The combustion chamber is connected to the ventilation chamber (1) so that the combustible gas introduced into the ventilation chamber (1) can enter the combustion chamber for combustion; a first heating structure is also provided in the combustion chamber, and the first heating structure is used for flowing water; the steam-water separator (5) is connected to the first heating structure and is used for separating liquid water and high-temperature steam; the invention is characterized in that it also includes an economizer (6), the economizer (6) is provided with a second heating structure, and the second heating structure is connected to an end of the first heating structure away from the steam-water separator (5); the cavity inside the economizer (6) is also connected to the combustion chamber, so that the high-temperature flue gas can pass through the combustion chamber and the economizer (6) in sequence; the economizer (6) is also provided with a chimney (7) for exhausting the flue gas; The ventilation chamber (1) comprises a gas inlet (1-1), a combustion-supporting air inlet (1-2), a mixing chamber (1-3) and a cooling structure; wherein the mixing chamber (1-3) is in the form of a tubular structure with a hollow interior; one end of the mixing chamber (1-3) is connected to the combustion chamber, and the other end of the mixing chamber (1-3) is provided with a combustion-supporting air inlet (1-2); a gas inlet (1-1) is also provided on the side of the mixing chamber (1-3); a cooling structure for preventing heat backflow is also provided between the mixing chamber (1-3) and the combustion chamber; and the cooling structure is also connected to a second heating structure so that a cooling heat-absorbing liquid flows into the second heating structure for heating.

2. A micro-furnace steam generating device according to claim 1, characterized in that: A hot water tank and a water pump are also arranged between the second heating structure and the first heating structure; the hot water tank is used to store liquid heated by the second heating structure; and the water pump is arranged between the hot water tank and the first heating structure.

3. A micro-furnace steam generating device according to claim 1, characterized in that: The cooling structure comprises a cooling water header (1-5) and a water cooling pipe structure (1-6) distributed in a labyrinth manner; the cooling water header (1-5) comprises an inlet end header (1-51) and an outlet end header (1-52) respectively arranged at two ends of the water cooling pipe structure (1-6); the water cooling pipe structure (1-6) is located between the mixing chamber (1-3) and the combustion chamber.

4. A micro-furnace steam generating device according to claim 3, characterized in that: The water cooling pipe structure (1-6) comprises a plurality of water cooling pipes arranged in parallel and at equal intervals; the cross-section of the water cooling pipes is Z-shaped, and different water cooling pipes are located on the same horizontal plane.

5. A micro-furnace steam generating device according to claim 4, characterized in that: A high emissivity coating (1-7) is also provided on one side of the water cooling tube close to the combustion chamber.

6. The micro-furnace steam generating device according to claim 1, characterized in that: A flow diversion structure is also provided between the mixing chamber (1-3) and the cooling structure; the flow diversion structure comprises a trumpet-shaped flow diversion shell and a flow diversion plate; wherein the side with a larger opening in the flow diversion shell is connected to the cooling structure, and the side with a smaller opening is connected to the mixing chamber (1-3); and a plurality of flow diversion plates are provided between the flow diversion shells.

7. The micro-furnace steam generating device according to claim 1, characterized in that: The first heating structure comprises a radiation heating zone (2) and a convection heating surface (4); the radiation heating zone (2) and the convection heating surface (4) are arranged in sequence from top to bottom in the combustion chamber; the radiation heating zone (2) is the location where the gas burns; the radiation heating zone (2) is connected to the convection heating surface (4); the convection heating surface (4) comprises a plurality of fin tubes (4-1), two rows of fin tubes (4-1) form a group, and the convection heating surface (4) comprises 3 to 4 groups of fin tubes (4-1); the fin tubes (4-1) in the same row of fin tubes (4-1) are distributed from top to bottom, the upstream and downstream spacing of adjacent fin tubes (4-1) is 80 mm, and the spacing of adjacent fin tubes (4-1) in the same group of fin tubes (4-1) is 50 mm.

8. The micro-furnace steam generating device according to claim 7, characterized in that: The cross section of the fin tube (4-1) is H-shaped; the thickness of the fin tube (4-1) is 2 mm, and the distance between adjacent fins in the fin tube (4-1) is 4 mm.

9. A steam generation method, characterized in that: Based on the steam generating device according to any one of claims 1 to 8, the steam generating method comprises the following steps: Step 1: water flows into the water cooling pipe structure (1-6), absorbs heat in the water cooling pipe and then enters the second heating structure; Step 2: The flue gas after cooling around the second heating structure heats the water flow in the second heating structure, and then the water flow heated to 60°C~70°C enters the hot water tank; Step 3: The water in the hot water tank is pumped to the first heating structure by a water pump. The water flows through the convection heating surface (4) and the periphery of the radiation heating area (2) of the first heating structure, and finally forms water vapor which is transported outward.

Images