Closed type dining blast gas stove for recovering flue gas waste heat

Abstract

The utility model belongs to the technical field of gas stove design, and particularly relates to a closed type dining blast gas stove for recovering smoke waste heat, which is characterized in that a pot body is arranged at the top of a stove body, the bottom of the stove body is connected with a smoke exhaust pipeline, and a gas pipeline and an air pipeline are arranged in the smoke exhaust pipeline; the air pipeline further comprises a bottom air inlet cavity, a top air outlet cavity and a plurality of air guide pipes connected between the bottom air inlet cavity and the top air outlet cavity, and the air guide pipes are arranged at intervals. The gas pipeline is coaxially arranged in the air pipeline, the outer wall of the gas pipeline, the bottom gas inlet cavity and the top gas outlet cavity are connected into a whole, and the gas guide pipe and the gas pipeline are arranged in a spaced mode. A waste heat recovery pipeline is arranged at the bottom of the smoke exhaust pipeline, and a heat exchanger is arranged in the waste heat recovery pipeline. According to the gas stove, waste heat of smoke can be used for preheating gas and air, the preheating area is larger, the preheating stroke is longer, the preheating efficiency is higher, and recycling of the waste heat of the smoke can be further achieved through the heat exchanger.

Description

Technical Field

[0001] This utility model belongs to the technical field of gas stove design, specifically relating to a closed-type blast gas stove for dining that recovers waste heat from flue gas. Background Technology

[0002] Traditional forced-draft gas stoves directly burn gas and air after premixing them, without preheating the gas and air. This results in insufficient combustion temperature and low thermal efficiency. Furthermore, traditional forced-draft gas stoves recover waste heat through complex piping systems, such as traditional heat exchangers. This structure is costly, difficult to maintain, and unlikely to be widely adopted. While the existing patent (CN102829495B) discloses a structure that uses flue gas to preheat gas and air, this solution involves premixing the gas and air first, with the flue gas preheating the premixed gas. This structure, which only preheats the mixed gas, has a small preheating area, a short preheating stroke, and limited preheating effect. Utility Model Content

[0003] This utility model provides a closed-type forced-draft gas stove for dining that recovers waste heat from flue gas, comprising: a trumpet-shaped stove body; a pot body placed at the trumpet opening at the top of the stove body; the stove body and the pot body enclosing a closed combustion chamber; a flue pipe connected to the bottom of the stove body; the combustion chamber and the flue pipe communicating with each other; a gas pipe and an air pipe are provided inside the flue pipe; the air pipe includes a bottom air inlet chamber, a top air outlet chamber, and multiple air guide pipes connecting the bottom air inlet chamber and the top air outlet chamber, the multiple air guide pipes being spaced apart from each other; the gas pipe is coaxially arranged inside the air pipe; the outer wall of the gas pipe is integrally connected to the bottom air inlet chamber and the top air outlet chamber, and the air guide pipes are connected to the gas pipe. The gas pipes are spaced apart from each other; a mixing plate and a combustion plate are arranged from bottom to top in the top gas outlet chamber, and a mixing chamber is constructed between the mixing plate and the combustion plate. Several first gas outlets communicating with the mixing chamber are provided on the side wall of the gas pipe, and several second gas outlets communicating with the combustion chamber are provided on the side wall of the gas pipe. The bottom of the exhaust pipe and the bottom of the air pipe are both connected to the stove base. The bottom air inlet chamber is connected to the blower, and the bottom end of the gas pipe is connected to an external gas source. A waste heat recovery pipe communicating with the exhaust pipe is provided on the bottom side wall of the exhaust pipe. A heat exchanger is provided in the waste heat recovery pipe. The cold water inlet of the heat exchanger is connected to tap water, and the hot water outlet of the heat exchanger is connected to an external load.

[0004] In one specific embodiment, the combustion chamber is provided with a trumpet-shaped baffle plate inside. The bottom of the baffle plate is connected to the top air outlet chamber of the air duct as a whole. The baffle plate divides the combustion chamber into a combustion chamber and a smoke exhaust chamber that are connected at the top. The combustion chamber is connected to the mixing chamber, and the smoke exhaust chamber is connected to the smoke exhaust duct.

[0005] In one specific embodiment, the gas guide pipe is a thin-walled pipe with a wall thickness of 2.5 mm, and the gas pipeline has a wall thickness of 5 mm.

[0006] In one specific embodiment, the air guide pipe is welded to both the bottom air inlet chamber and the top air outlet chamber as a single unit.

[0007] In one specific embodiment, the mixing disc includes a conical connecting portion and a perforated disc. The bottom end of the conical connecting portion is connected to the outer wall of the gas pipeline, and the perforated disc is connected to the top outer wall of the conical connecting portion. The first gas outlet is located at the same height as the top surface of the perforated disc.

[0008] In one specific embodiment, the longitudinal section of the mixing chamber has a structure that is narrow in the middle and wide at both ends.

[0009] In one specific embodiment, the top end of the gas pipeline is configured as a thin pipe section, the second gas outlet is disposed on the outer wall of the thin pipe section, and the second gas outlet is disposed close to the combustion plate.

[0010] In one specific embodiment, the heat exchanger is a spiral tube heat exchanger or a metal plate heat exchanger.

[0011] In one specific implementation, the load is a steam device.

[0012] This utility model has at least the following beneficial effects: The combustion chamber is enclosed by the stove body and pot body, and the forced oxygen supply by the blower ensures combustion efficiency, allowing the flue gas after combustion to flow back into the exhaust pipe for discharge; by placing the gas pipe and air pipe inside the exhaust pipe, the waste heat of the flue gas can be used to preheat the gas and air; by setting the air pipe to include a bottom air inlet chamber, a top air outlet chamber, and multiple air guide pipes, with the multiple air guide pipes spaced apart, the contact preheating area and preheating stroke between the flue gas and the air and gas pipes are greatly increased, thus significantly improving preheating efficiency; by installing a heat exchanger inside the waste heat recovery pipe, the recovery and utilization of waste heat from the flue gas is further realized. Attached Figure Description

[0013] Figure 1 This is a longitudinal cross-sectional structural diagram of an embodiment of the present utility model.

[0014] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0015] Figure 3 This is a structural diagram of the gas pipeline, air pipeline and baffle plate assembled in an embodiment of this utility model.

[0016] Reference numerals: 1. Stove body; 2. Pot body; 3. Exhaust pipe; 4. Gas pipe; 41. First gas outlet; 42. Second gas outlet; 5. Air pipe; 5. Bottom air inlet chamber; 52. Top air outlet chamber; 53. Air guide pipe; 521. Mixing disc; 521a. Conical connecting part; 521b. Perforated disc; 522. Combustion disc; 523. Mixing chamber; 6. Baffle plate; 61. Combustion chamber; 62. Exhaust chamber; 7. Waste heat recovery pipe; 71. Heat exchanger. Detailed Implementation

[0017] Please see Figures 1-3 The present invention provides a closed-type gas stove for cooking that recovers waste heat from flue gas, comprising: a horn-shaped stove body 1, a pot body 2 placed at the horn opening at the top of the stove body 1, the stove body 1 and the pot body 2 forming a closed combustion chamber, and a flue pipe 3 connected to the bottom of the stove body 1, the combustion chamber and the flue pipe 3 being connected.

[0018] The exhaust duct 3 contains a gas duct 4 and an air duct 5. The air duct 5 includes a bottom air inlet chamber 51, a top air outlet chamber 52, and multiple air guide pipes 53 connecting the bottom air inlet chamber 51 and the top air outlet chamber 52. The multiple air guide pipes 53 are spaced apart from each other. The air guide pipes 53 are thin-walled pipes with a wall thickness of 2.5 mm. The bottom air inlet chamber 51, the top air outlet chamber 52, and the gas duct 4 have a wall thickness of 5 mm. Making the air guide pipes 53 thin-walled pipes significantly improves heat transfer efficiency. The air guide pipes 53 are welded to the bottom air inlet chamber 51 and the top air outlet chamber 52 as a whole, further improving heat transfer efficiency and robustness.

[0019] The gas pipe 4 is coaxially arranged inside the air pipe 5. The outer wall of the gas pipe 4 is connected to the bottom air inlet chamber 51 and the top air outlet chamber 52 as a whole. The gas guide pipe 53 is spaced apart from the gas pipe 4. This structure greatly increases the contact area between the gas pipe 4 and the air pipe 5 and the flue gas in the exhaust pipe 3, thereby improving the preheating efficiency. In addition, the gas pipe 4 and the air pipe 5 are arranged inside the exhaust pipe 3 from the bottom air inlet position to the top air outlet position, so the preheating journey of the flue gas to the gas and air is longer.

[0020] The top air outlet chamber 52 is provided with a mixing disc 521 and a combustion disc 522 arranged from bottom to top. The mixing disc 521 and the combustion disc 522 are connected to form a mixing chamber 523. The longitudinal section of the mixing chamber 523 is narrow in the middle and wide at both ends. Air and fuel gas undergo an acceleration and deceleration process in the mixing chamber 523, which makes the mixing more complete.

[0021] The combustion chamber is equipped with a trumpet-shaped baffle 6. The bottom of the baffle 6 is connected to the top air outlet chamber 52 of the air duct 5. The baffle 6 divides the combustion chamber into a combustion chamber 61 and a smoke exhaust chamber 62 that are connected at the top. The combustion chamber 61 is connected to the mixing chamber 523, and the smoke exhaust chamber 62 is connected to the smoke exhaust duct 3.

[0022] The side wall of the gas pipeline 4 is provided with several first gas outlets 41 communicating with the mixing chamber 523. The mixing disc 521 includes a conical connecting part 521a and a perforated disc 521b. The bottom end of the conical connecting part 521a is connected to the outer wall of the gas pipeline 4, and the perforated disc 521b is connected to the top outer wall of the conical connecting part 521a. The first gas outlets 41 are located at the same height as the top surface of the perforated disc 521b. The top end of the gas pipeline 4 is configured as a thin pipe section, and the outer wall of the thin pipe section is provided with several second gas outlets 42 communicating with the combustion chamber. The second gas outlets 42 are located close to the combustion disc 522.

[0023] The bottom of the exhaust duct 3 and the bottom of the air duct 5 are both connected to the stove base. The bottom air intake chamber 51 is connected to the blower, and the bottom end of the gas duct 4 is connected to the external gas source. The blower inputs air from the bottom air intake chamber 51 of the air duct 5, which flows into the mixing chamber 523 after passing through multiple air guide pipes 53. A portion of the gas from the external gas source flows into the mixing chamber 523 through the bottom end of the gas duct 4 and then through the first gas outlet 41 to mix with the air. The mixed gas continues to move upward to the combustion plate 522 for combustion, while the other portion of the gas directly reaches the combustion plate 522 through the second gas outlet 42, where it is further mixed with the mixed gas before combustion, which greatly improves the combustion efficiency.

[0024] A waste heat recovery pipe 7, connected to the bottom side wall of the flue gas duct 3, is installed. A heat exchanger 71, a spiral tube heat exchanger, is installed inside the waste heat recovery pipe 7. The cold water inlet of the spiral tube heat exchanger is connected to tap water, and the hot water outlet is connected to an external load, which is a steam device. Alternatively, in other embodiments of this invention, the heat exchanger 71 can be a metal plate heat exchanger, and the load can be other hot water-using equipment.

[0025] The flue gas generated by combustion flows from the combustion chamber 61 through the exhaust chamber 62, the exhaust pipe 3, and the waste heat recovery pipe 7 under the guidance of the baffle plate 6, thereby preheating the air and gas. The waste heat is further recovered through the heat exchanger 71 in the waste heat recovery pipe 7.

[0026] Fluent software was used to simulate the effect of gas flow rate changes on the temperature field of the gas stove and the waste heat recovery device. The blower was controlled to input air into the bottom air intake chamber 51 at a speed of 0.45 m / s, and high flame, medium flame and low flame were simulated with gas flow rates of 0.2 m / s, 0.15 m / s and 0.1 m / s respectively. The simulation calculation results are shown in Table 1.

[0027]

[0028] Table 1 shows the simulated numerical values ​​of the temperature field of the gas stove and the bottom of the pot under different gas flow rates.

[0029] As can be seen from Table 1, after recovering the waste heat of the flue gas, the average temperature of the mixed gas at the outlet of the mixing chamber 523 of the gas stove reached 1221.5K, 1046.9K and 727.7K respectively, proving that the gas stove has a significant preheating effect on gas and air.

[0030] In Fluent software, the solid portion of the wall was removed so that Fluent would no longer calculate heat transfer from the wall, and the flue gas would no longer preheat the air and fuel gas. With other conditions remaining unchanged, the simulation was performed again, and the simulation results are shown in Table 2.

[0031] Gas flow velocity (m / s) The highest overall temperature (K) of the gas stove Average temperature of the bottom of the pot (K) Excess air coefficient α 0.2 2221.4 1359.5 1.4038 0.15 2191.9 1228.3 1.8717 0.1 2123.4 906.3 2.8076

[0032] Table 2 shows the simulated numerical values ​​of the temperature field of the gas stove and the bottom of the pot under different gas flow rates after the wall surface is removed.

[0033] The comparison results in Tables 1 and 2 show that the gas stove preheats the air and gas by recovering the preheating of flue gas, which not only achieves waste heat recovery and utilization but also significantly promotes the combustion of gas.

[0034] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions and substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A closed-type forced-draft gas stove for dining that recovers waste heat from flue gas, characterized in that, include: A flared stove body (1) has a pot body (2) placed at the flared opening at the top. The stove body (1) and the pot body (2) enclose a combustion chamber with a closed structure. A flue pipe (3) is connected to the bottom of the stove body (1), and the combustion chamber and the flue pipe (3) are connected. A gas pipe (4) and an air pipe (5) are provided inside the flue pipe (3). The air pipe (5) includes a bottom air inlet chamber (51), a top air outlet chamber (52), and a connecting... Multiple air guide pipes (53) are arranged between the bottom air inlet chamber (51) and the top air outlet chamber (52), with the multiple air guide pipes (53) spaced apart from each other; the gas pipeline (4) is coaxially arranged inside the air pipeline (5), and the outer wall of the gas pipeline (4) is connected to the bottom air inlet chamber (51) and the top air outlet chamber (52) as a whole, with the air guide pipes (53) and the gas pipeline (4) spaced apart from each other; the top air outlet chamber (52) is arranged between the bottom air inlet chamber (51) and the top air outlet chamber (52). A mixing disc (521) and a combustion disc (522) are arranged from bottom to top inside the gas chamber (52). The mixing disc (521) and the combustion disc (522) form a mixing chamber (523). Several first gas outlets (41) communicating with the mixing chamber (523) are provided on the side wall of the gas pipe (4). Several second gas outlets (42) communicating with the combustion chamber are provided on the side wall of the gas pipe (4). The bottom of the exhaust pipe (3) and the air chamber are connected to the combustion chamber. The bottom of the gas pipe (5) is connected to the stove base. The bottom air inlet chamber (51) is connected to the blower. The bottom end of the gas pipe (4) is connected to the external gas source. The bottom side wall of the exhaust pipe (3) is provided with a waste heat recovery pipe (7) connected to the exhaust pipe (3). A heat exchanger (71) is provided in the waste heat recovery pipe (7). The cold water inlet of the heat exchanger (71) is connected to the tap water. The hot water outlet of the heat exchanger (71) is connected to the external load.

2. The enclosed-type flue gas stove for recovering waste heat according to claim 1, characterized in that, The combustion chamber is equipped with a horn-shaped baffle (6) inside. The bottom of the baffle (6) is connected to the top air outlet chamber (52) of the air duct (5) as a whole. The baffle (6) divides the combustion chamber into a combustion chamber (61) and a smoke exhaust chamber (62) that are connected at the top. The combustion chamber (61) is connected to the mixing chamber (523), and the smoke exhaust chamber (62) is connected to the smoke exhaust duct (3).

3. The enclosed-type flue gas stove for recovering waste heat according to claim 1, characterized in that, The gas duct (53) is a thin-walled pipe with a wall thickness of 2.5 mm, and the gas pipeline (4) has a wall thickness of 5 mm.

4. The enclosed-type flue gas stove for recovering waste heat according to claim 3, characterized in that, The air duct (53) is welded to the bottom air inlet chamber (51) and the top air outlet chamber (52) as a whole.

5. The enclosed-type flue gas stove for recovering waste heat according to claim 1, characterized in that, The mixing disc (521) includes a tapered connecting part (521a) and a perforated disc (521b). The bottom end of the tapered connecting part (521a) is connected to the outer wall of the gas pipeline (4), and the perforated disc (521b) is connected to the top outer wall of the tapered connecting part (521a). The first gas outlet (41) is located at the same height as the top surface of the perforated disc (521b).

6. The enclosed-type flue gas stove for recovering waste heat according to claim 1, characterized in that, The longitudinal section of the mixing chamber (523) is narrow in the middle and wide at both ends.

7. The enclosed-type flue gas stove for recovering waste heat according to claim 1, characterized in that, The top end of the gas pipeline (4) is configured as a thin pipe section, and the second gas outlet (42) is located on the outer wall of the thin pipe section, and the second gas outlet (42) is located close to the combustion plate (522).

8. The enclosed-type flue gas stove for recovering waste heat according to claim 1, characterized in that, The heat exchanger (71) is a spiral tube heat exchanger or a metal plate heat exchanger.

9. The enclosed-type flue gas stove for recovering waste heat according to any one of claims 1-8, characterized in that, The load is a steam equipment.

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