Recirculating flue gas and cold combustion-supporting air mixing device of gas-fired hot water boiler

Abstract

The utility model relates to the technical field of gas-fired hot water boilers, in particular to a gas-fired hot water boiler recirculation flue gas and cold combustion air mixing device which comprises a box body with a mixing chamber, a cold combustion air inlet and a mixed gas outlet are formed in the side edge of the box body, a plurality of recirculation flue gas branch pipes are arranged in the mixing chamber, and the cold combustion air inlet is communicated with the mixed gas outlet. A plurality of flue gas nozzles are formed in the recirculating flue gas branch pipes, the tops of the recirculating flue gas branch pipes extend out of the box body and then are connected with a recirculating flue gas main pipe, the bottoms of the recirculating flue gas branch pipes are connected with a condensate water pipe, the condensate water pipe is further connected with a condensate water discharge pipe, and the condensate water discharge pipe is connected with a water inlet pipe. The condensate water discharge pipe extends out of the bottom edge of the box body; the bottom edge of the box body is in a funnel shape, and a box body liquid discharging connector is arranged at the lowest position of the box body. The device is simple in structure, convenient to assemble and maintain and capable of effectively filtering condensate water generated in recycled flue gas and cold combustion-supporting air.

Description

TECHNICAL FIELD

[0001] The utility model relates to a gas hot water boiler technical field especially relates to a gas hot water boiler recirculation flue gas and cold combustion air mixing device. BACKGROUND

[0002] The gas hot water boiler is one kind of hot water boiler, mainly based on the heat energy produced by gas combustion, through the heat exchanger to transmit the heat energy to the water, the specific process includes three steps of gas combustion, heat energy transmission and water circulation. The gas burns in the burner, produces high-temperature flue gas, and the flue gas exchanges heat with the water through the heat exchanger, and the heat energy is transmitted to the water. The temperature of the water rises after being heated, and is sent into the heating system or hot water supply system through the circulating pump.

[0003] In order to realize clean combustion, in addition to adopting high-efficiency, energy-saving and environment-friendly low-NOx combustion machine, flue gas recirculation (FGR) combustion technology is one of the main technical measures to reduce NOx emission pollution in boiler combustion. Flue gas recirculation combustion technology refers to the combustion mode that part of the flue gas produced by combustion is mixed with combustion air and then participates in the combustion process again, and its essence is to control the concentration of combustion temperature oxides by introducing the flue gas produced by combustion into the combustion area again, so as to realize the effect of reducing NOx emission and saving energy.

[0004] However, when the gas hot water boiler adopts the flue gas recirculation (FGR) combustion technology, the recirculated flue gas is mostly directly connected to the pipeline before the inlet of the combustion air fan, which inevitably causes uneven mixing of the recirculated flue gas and the cold combustion air, and then causes the water vapor in the recirculated flue gas to condense into water, which leaks everywhere, and the condensed water may freeze and adhere to the impeller of the combustion air fan, affecting the normal operation of the fan.

[0005] Therefore, a new technical solution is needed to solve the above technical problems. UTILITY MODEL CONTENTS

[0006] The utility model discloses a gas hot water boiler recirculation flue gas and cold combustion air mixing device, which solves the technical problems that the recirculated flue gas is directly connected to the pipeline before the inlet of the combustion air fan, which inevitably causes uneven mixing of the recirculated flue gas and the cold combustion air, and then causes the water vapor in the recirculated flue gas to condense into water, which leaks everywhere, and the condensed water may freeze and adhere to the impeller of the combustion air fan, affecting the normal operation of the fan.

[0007] The above-mentioned purpose is realized by the following technical scheme:

[0008] A mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler includes a housing with a mixing chamber. A cold combustion air inlet and a mixed gas outlet are located on the side of the housing. Several recirculated flue gas branch pipes are arranged within the mixing chamber, each branch pipe having several flue gas nozzles. The top of each branch pipe extends out of the housing and connects to a main recirculated flue gas pipe. The bottom of each branch pipe connects to a condensate pipe, which is also connected to a condensate drain pipe extending out of the bottom edge of the housing. The bottom edge of the housing is funnel-shaped, with a drain port located at the lowest point.

[0009] Furthermore, a condensate seal and discharge device are provided at the bottom of the box, and the condensate discharge pipe and the box drain interface are respectively connected to the condensate seal and discharge device.

[0010] Furthermore, the condensate seal and discharge device is provided with a condensate drain valve and a drain valve from top to bottom.

[0011] Furthermore, each of the recirculated flue gas branch pipes is vertically arranged in the mixing chamber.

[0012] Furthermore, a funnel-shaped guide section is provided between the recirculated flue gas branch pipe and the condensate pipe.

[0013] Furthermore, there are three recirculated flue gas branch pipes, arranged side by side and at equal intervals.

[0014] Furthermore, each of the recirculated flue gas branch pipes has a number of rows of flue gas nozzles on the same side.

[0015] Furthermore, the recirculated flue gas branch pipe is provided with two rows of flue gas nozzles, with five flue gas nozzles in each row, and they are arranged in a staggered manner.

[0016] Furthermore, a 45° angle is formed between the two rows of flue gas nozzles.

[0017] Furthermore, the cold combustion air inlet and the mixed gas outlet are perpendicular to each other. Beneficial effects

[0018] This invention provides a mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler. By employing flue gas recirculation combustion technology, it reduces NOx emissions from the boiler while also minimizing condensate leakage caused by insufficient mixing of recirculated flue gas and cold combustion air in cold winters. Furthermore, it reduces the risk of condensate freezing and adhering to the combustion fan impeller, thus ensuring normal combustion of natural gas and normal heating supply from the gas-fired hot water boiler. This device is not only simple in structure and easy to assemble and maintain, but also effectively filters out condensate generated in the recirculated flue gas and cold combustion air. Attached Figure Description

[0019] Figure 1 This is a first-view structural schematic diagram of a gas-fired hot water boiler recirculation flue gas and cold combustion air mixing device according to the present invention.

[0020] Figure 2 This is a second-view structural schematic diagram of a gas-fired hot water boiler recirculation flue gas and cold combustion air mixing device according to the present invention.

[0021] Figure 3 This is a third-view structural schematic diagram of a gas-fired hot water boiler recirculation flue gas and cold combustion air mixing device according to the present invention.

[0022] Figure 4 This is a schematic diagram showing the connection of a condensate seal and a discharge device to a gas-fired hot water boiler recirculation flue gas and cold combustion air mixing device as described in this utility model.

[0023] Illustration markings:

[0024] 1-Box body, 2-Mixing chamber, 3-Cold combustion air inlet, 4-Mixed gas outlet, 5-Recirculated flue gas branch pipe, 6-Flue gas nozzle, 7-Recirculated flue gas main pipe, 8-Condensate pipe, 9-Condensate drain pipe, 10-Box body drain interface, 11-Condensate seal and drain device, 12-Condensate drain valve, 13-Drain valve, 14-Guide section. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the figures and embodiments.

[0026] like Figures 1-3As shown, this solution provides a mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler, including a housing 1 with a mixing chamber 2. A cold combustion air inlet 3 and a mixed gas outlet 4 are provided on the side of the housing 1. Several recirculated flue gas branch pipes 5 are provided in the mixing chamber 2. Several flue gas nozzles 6 are opened on the recirculated flue gas branch pipes 5. The top of each recirculated flue gas branch pipe 5 extends out of the housing 1 and is connected to the main recirculated flue gas pipe 7. The bottom of each recirculated flue gas branch pipe 5 is connected to a condensate pipe 8. A condensate drain pipe 9 is also connected to the condensate pipe 8. The condensate drain pipe 9 extends out of the bottom edge of the housing 1 to drain condensate.

[0027] The bottom edge of the box 1 is funnel-shaped, and a box drain port 10 is provided at the lowest position to drain condensate water to the outside.

[0028] In this embodiment, the cold combustion air inlet 3 is used to facilitate the introduction of cold combustion air into the mixing chamber 2, and the flue gas nozzle 6 is used to facilitate the introduction of recirculated flue gas into the mixing chamber 2. After the cold combustion air and the recirculated flue gas are fully mixed in the mixing chamber 2, they are input to the combustion fan connected thereto through the mixed gas outlet 4, thereby providing a high-temperature mixed gas with extremely low water content for the gas-fired hot water boiler.

[0029] like Figure 4 As shown, in this embodiment, a condensate seal and discharge device 11 is also provided below the box body 1. The condensate discharge pipe 9 and the box body drain port 10 are respectively connected to the condensate seal and discharge device 11 to discharge the condensate generated in the pipe into the condensate seal and discharge device.

[0030] Specifically, the condensate seal and discharge device 11 is provided with a condensate drain valve 12 and a drain valve 13 from top to bottom. The condensate drain valve 12 is used to output the condensate collected in the device and located in the upper layer, which can be output to the sump through the pipeline. The drain valve 13 is used to output the solid residue collected in the device and deposited in the lower layer, thereby cleaning the condensate seal and discharge device.

[0031] As an optimization of this embodiment, each of the recirculated flue gas branch pipes 5 is vertically arranged in the mixing chamber 2. This structure can ensure that the condensate formed flows along the pipe wall of the recirculated flue gas branch pipe to the condensate discharge pipe under the action of gravity.

[0032] In addition, a funnel-shaped guide section 14 is provided between the recirculated flue gas branch pipe 5 and the condensate pipe 8 so as to smoothly guide the condensate on the pipe wall of the recirculated flue gas branch pipe 5 into the condensate pipe 8.

[0033] As a specific embodiment of this solution, there are 3 recirculated flue gas branch pipes 5, arranged side by side and at equal intervals; each of the recirculated flue gas branch pipes 5 has several rows of flue gas nozzles 6 on the same side.

[0034] Specifically, the recirculated flue gas branch pipe 5 is provided with two rows of flue gas nozzles 6, with five nozzles 6 in each row, arranged in a staggered manner. This staggered arrangement ensures the density of flue gas discharged from the recirculated flue gas branch pipe 5, thereby facilitating more thorough mixing with the cold combustion air that has entered the mixing chamber 2.

[0035] In this embodiment, the two rows of flue gas nozzles 6 form a 45° angle between them. By adopting the angle, the flue gas will not be blown directly toward the mixed gas outlet 4, but will be fully mixed with the cold combustion air that has entered the mixing chamber 2 before being discharged along the mixed gas outlet 4.

[0036] As a further optimization of this embodiment, the cold combustion air inlet 3 and the mixed gas outlet 4 are perpendicular to each other. Compared with the horizontal straight-line arrangement, the presence of a right angle ensures that the cold combustion air entering the mixing chamber 2 from the cold combustion air inlet 3 can stay in the mixing chamber 2 for a short time, thereby facilitating full mixing with the flue gas ejected from the flue gas nozzle 6.

[0037] The above description is merely a preferred embodiment of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be conceived by those skilled in the art within the scope of the technology disclosed in this utility model are included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. A device for mixing recirculated flue gas and cold combustion air in a gas-fired hot water boiler, characterized in that, The enclosure includes a housing (1) with a mixing chamber (2), a cold combustion air inlet (3) and a mixed gas outlet (4) on the side of the housing (1), and a plurality of recirculated flue gas branch pipes (5) are provided in the mixing chamber (2). A plurality of flue gas nozzles (6) are provided on the recirculated flue gas branch pipes (5). The top of each recirculated flue gas branch pipe (5) extends out of the housing (1) and is connected to the recirculated flue gas main pipe (7). The bottom of each recirculated flue gas branch pipe (5) is connected to the condensate pipe (8). A condensate drain pipe (9) is also connected to the condensate pipe (8). The condensate drain pipe (9) extends out of the bottom edge of the housing (1). The bottom edge of the box (1) is funnel-shaped, and a box drain port (10) is provided at the lowest position.

2. The mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 1, characterized in that, A condensate seal and discharge device (11) is also provided below the box (1), and the condensate discharge pipe (9) and the box drain interface (10) are respectively connected to the condensate seal and discharge device (11).

3. The mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 2, characterized in that, The condensate seal and discharge device (11) is provided with a condensate drain valve (12) and a drain valve (13) from top to bottom.

4. The mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 1, characterized in that, Each of the recirculated flue gas branch pipes (5) is vertically arranged in the mixing chamber (2).

5. A mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 1 or 4, characterized in that, A funnel-shaped guide section (14) is provided between the recirculated flue gas branch pipe (5) and the condensate pipe (8).

6. The mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 1, characterized in that, There are 3 recirculated flue gas branch pipes (5), which are arranged side by side and at equal intervals.

7. The mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 6, characterized in that, Each of the recirculated flue gas branch pipes (5) has a number of rows of flue gas nozzles (6) on the same side.

8. The mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 6, characterized in that, The recirculated flue gas branch pipe (5) is provided with two rows of flue gas nozzles (6), each row containing 5 flue gas nozzles (6) arranged in a staggered manner.

9. The mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 7, characterized in that, The two rows of flue gas nozzles (6) form a 45° angle between them.

10. A mixing device for recirculated flue gas and cold combustion air in a gas-fired hot water boiler according to claim 1, characterized in that, The cold combustion air inlet (3) and the mixed gas outlet (4) are perpendicular to each other.

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