CN104501397B - A kind of compound backwater condensing natural gas hot water's boiler of fin panel casing - Google Patents

Abstract

A kind of compound backwater condensing natural gas hot water's boiler of fin panel casing, air collector and a pipe network water supply pipe in pipeline（21）Connection；A pipe network return pipe in pipeline（20）Backwater pass through successively under energy-saving appliance header of catchmenting, lower header, heat exchanger tube I, upper collecting chamber, on catchment header, burner hearth（5）Rear fin panel casing, mid-board fin panel casing, left fin panel casing, prepattern water-cooling wall, convection bank, finally collect in upper drum；Pipeline also includes secondary pipe network return pipe（22）, secondary pipe network feed pipe（23）, the backwater of secondary pipe network return pipe divides water header by condenser successively（31）, heat exchanger tube II（32）, header of catchmenting（33）；The one end for header of catchmenting is connected with secondary pipe network feed pipe, other end closure.The present invention has certain versatility, it is possible to increase the heat utilization ratio of boiler, reduces fuel cost during operation, the service life of prolonged boiler equipment.

Description

A membrane-type water-cooled wall composite return water condensing natural gas hot water boiler

technical field

The invention relates to a natural gas hot water boiler, in particular to a membrane type water wall composite return water condensing natural gas hot water boiler, which belongs to the technical field of deep recovery of boiler heat.

Background technique

Coal-fired hot water boilers are usually used for heating in winter. However, due to the small steam capacity of coal-fired hot water boilers, the discharge of pollutants from boilers is difficult to meet the standards. In addition, heating boilers are generally built in or around cities, which is harmful to the health of citizens. The threat is greater, and now a large number of coal-fired hot water boilers are replaced by natural gas boilers to reduce environmental pollution caused by coal-fired heating.

The traditional natural gas boiler adopts the countercurrent heat exchange between the return water of the primary pipe network and the flue gas, and the return water temperature of the primary pipe network is not lower than 70°C. The flue gas temperature is high, resulting in low thermal efficiency; in addition, after the combustion of natural gas, about 18% of the water vapor is discharged in the gaseous state in the flue gas. The latent heat of vaporization of water vapor is lost with the flue gas, resulting in energy waste; in addition, when the natural gas hot water boiler is heated in winter, the boiler operates below the rated load for a long time, and the heating surface at the rear also has the problem of low-temperature corrosion.

Contents of the invention

Aiming at the problems existing in the above-mentioned prior art, the present invention provides a membrane-type water-cooled wall composite return water condensing natural gas hot water boiler, which has certain versatility, improves the heat utilization rate of the boiler, reduces the fuel cost during operation, and prolongs the life of the boiler. The service life of the equipment.

In order to achieve the above purpose, the technical solution adopted by the present invention is: a membrane type water-cooled wall composite return water condensing natural gas hot water boiler, including an upper drum, a lower drum, a furnace, a turning flue, an economizer, a condenser, Convection tube bundles and pipelines, safety valves, gas collection tanks, and pipe body water inlet connections are installed on the upper drum from left to right. The gas collection tank is connected to the primary pipe network water supply pipe of the pipeline; the primary pipe network return pipe of the pipeline The return water of the economizer passes through the lower header, lower header, heat exchange tube I, upper header, upper header, rear membrane water wall of the furnace, middle partition wall membrane water wall, left Membrane water wall, front membrane water wall, convection tube bundle, and finally connected to the upper drum; the upper end of the convection tube bundle is connected to the upper drum, the lower end is connected to the lower drum, one end of the turning flue is connected to the convection tube bundle, and the other end It is connected to the flue gas inlet of the economizer, the flue gas outlet of the economizer is connected to the flue gas inlet of the condenser, and the flue gas outlet of the condenser is connected to the chimney; It is surrounded by four steel plates on the outside; one end of the side wall is connected to the turning flue, and the other end is connected to the side plate of the condenser.

The pipeline also includes the return water pipe of the secondary pipe network and the water supply pipe of the secondary pipe network. One end of the water header is connected to the water supply pipe of the secondary pipe network, and the other end is blocked.

The rear membrane water cooling wall, the middle membrane water cooling wall, the left membrane water cooling wall and the front membrane water cooling wall are all welded by pipes and flat steel, and thermal insulation cotton is laid on the outside of the membrane water cooling wall.

Heat exchange tube I and heat exchange tube II are spiral finned tubes.

The heat exchange tube I, heat exchange tube II and side plates of the economizer are made of ND steel, Corten steel or austenitic stainless steel.

The convection tube bundle is composed of at least one light tube, and the tubes in the tube group are arranged in parallel.

The turning flue is a hollow frame structure surrounded by four steel plates, and the horizontal projection is a 90° elbow.

A fire viewing hole is arranged on the left membrane water cooling wall; an explosion-proof door is installed above the furnace of the left membrane water cooling wall near the furnace outlet.

A platform for maintenance is provided under the burner.

The present invention adopts the return water pipe of the primary pipe network and the return water pipe of the secondary pipe network to cool the flue gas in a graded manner. Between 40 and 50 ℃, the return water of the return pipe of the primary pipe network enters the economizer and exchanges heat with the flue gas countercurrently, so that the flue gas is cooled to 80~120 ℃, and the return water of the return water pipe of the secondary pipe network enters the condenser and then with the flue gas Gas countercurrent heat exchange cools the flue gas to 45~55°C, the dew point of the water vapor in the flue gas is 60°C, and 30~70% of the water vapor in the flue gas condenses into liquid water, so the water vapor in the flue gas is released A large amount of latent heat of vaporization is produced, and the boiler saves 6~15Nm ³ natural gas per ton of steam compared with traditional natural gas boilers, which improves the thermal efficiency of the boiler and reduces the fuel cost during operation; the furnace adopts a membrane water-cooled wall structure, and insulation cotton can be used for heat preservation. The heat preservation workload is small, the foundation load is small, and positive pressure in the furnace can be realized to enhance combustion. The system is only equipped with a blower, not an induced draft fan, reducing power consumption and initial investment costs; the heating surface of the economizer and condenser in contact with the flue gas and the flue gas The temperature of the channel wall is below the flue gas dew point temperature for a long time. Using ND steel, Corten steel or austenitic stainless steel can effectively reduce low-temperature corrosion and prolong the service life of the low-temperature heating equipment.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is the A-A sectional view of Fig. 2;

Fig. 4 is a B-B sectional view of Fig. 1 .

In the figure: 1. Front lower header, 2. Lower drum, 3. Burner, 4. Platform, 5. Furnace, 6. Front membrane water wall, 7. Front upper header, 8. Upper drum, 9. Safety valve, 10. Gas tank, 11. Main body water inlet pipe, 12. Rear upper header, 13. Rear membrane water wall, 14. Fire viewing hole, 15. Rear lower header, 16. Turning smoke Road, 17. Economizer, 18. Condenser, 19. Explosion-proof door, 20. Primary pipe network return pipe, 21. Primary pipe network water supply pipe, 22. Secondary pipe network return water pipe, 23. Secondary pipe network water supply pipe , 24, upper water header, 25, upper header, 26, heat exchange tube I, 27, lower header, 28, lower water header, 29, bracket I, 30, side wall, 31, water diversion Header; 32. Heat exchange tube II, 33. Water collection header, 34. Bracket II; 35. Side plate; 36. Left membrane water wall; 37. Middle partition wall membrane water wall; 38. Convection tube bundle.

detailed description

The present invention will be further described below in conjunction with accompanying drawing.

As shown in Figures 1 to 4, the membrane water wall composite return water condensing natural gas hot water boiler includes an upper drum 8, a lower drum 2, a furnace 5, a turning flue 16, an economizer 17, and a condenser 18 , convection tube bundle 38 and pipeline, safety valve 9, gas collection tank 10, body water inlet connection 11 in the pipeline are installed in sequence from left to right on the upper drum 8, the primary pipe network water supply pipe in the gas collection tank 10 and pipeline 21 connection; the return water of the primary pipe network return pipe 20 in the pipeline passes through the lower water header 28, the lower header 27, the heat exchange tube I26, the upper header 25, the upper water header 24, The rear membrane water cooling wall 13 of the furnace 5, the middle membrane water cooling wall 37, the left membrane water cooling wall 36, the front membrane water cooling wall 6, the convection tube bundle 38, and finally communicate with the upper drum 8; the upper end of the convection tube bundle 38 It is connected with the upper drum 8, and the lower end is connected with the lower drum 2; one end of the turning flue 16 is connected with the convection tube bundle 38, and the other end is connected with the flue gas inlet of the economizer 17, and the flue gas outlet of the economizer 17 is connected with the condenser 18 The flue gas inlet of the condenser 18 is connected to the chimney; the side wall 30 is surrounded by four steel plates attached to the upper header 25, the lower header 27, and the outside of the heat exchange tube I26; one end of the side wall 30 and The turning flue 16 is connected, and the other end is connected with the side plate 35 of the condenser 18; one end of the front upper header 7 and the rear upper header 12 of the furnace 5 is respectively connected with the upper drum 8, and the other end is blocked; the front lower header One end of the tank 1 and the rear lower header 15 are respectively connected with the lower drum 2, and the other end is blocked; the upper end of the front membrane water wall 6 is connected with the front upper header 7, and the lower end is connected with the front lower header 1; The burner 3 is installed on the membrane water wall 6; the upper end of the left membrane water wall 36 is connected with the upper drum 8, and the lower end is connected with the lower drum 2; the upper end of the rear membrane water wall 13 is connected with the upper rear header 12 , the lower end is connected with the rear lower header 15; the convection tube bundle 38 is composed of light pipes, the upper end of each tube is connected with the upper drum 8, and the lower end is connected with the lower drum 2; the upper water collection header 24 of the economizer 17 One end is connected to the water inlet pipe 11 of the body, and the other end is blocked. The side of the upper header 24 is connected to several upper headers 25; one end of the lower header 28 is connected to the return pipe 20 of the primary pipe network, and the other end is sealed. Blocking, the side of the lower header 28 is connected with several lower headers 27; the upper header 24, the lower header 28, the upper header 25, and the lower header 27 are all side openings Straight pipe; one end of the upper header 25 is connected to the upper water header 24, and the other end is blocked; one end of the lower header 27 is connected to the lower water header 28, and the other end is blocked; the upper end of the heat exchange tube I26 and The upper header 25 is connected, and the lower end is connected with the lower header 27; the bracket I29 is supported under the lower header 27, and the other end is fixed on the foundation; the side wall 30 is attached to the upper header 25, the lower header 27, the heat exchange tube I26 is surrounded by four steel plates on the outside; one end of the side wall 30 is connected to the turning flue 16, and the other end is connected to the side plate 35 of the condenser 18; one end of the heat exchange tube II32 is connected to the water diversion header 31, and the other end It is connected with the water collecting header 33; the side plate 35 is surrounded by four steel plates One end is connected to the side wall 30 of the economizer 17, and the other end is the flue gas outlet; the heat exchange tube II32 is supported on the support II34, and the support II34 is fixed on the foundation.

The pipeline also includes the return water pipe 22 of the secondary pipe network and the water supply pipe 23 of the secondary pipe network. 33; one end of the water collection header 33 is connected to the water supply pipe 23 of the secondary pipe network, and the other end is blocked.

Further, the rear membrane water cooling wall 13, the middle membrane water cooling wall 37, the left membrane water cooling wall 36, and the front membrane water cooling wall 6 are all welded by pipes and flat steel, and thermal insulation cotton is laid on the outside of the membrane water cooling wall , the water wall can be insulated, and the welded membrane water wall can effectively seal the flue gas in the furnace.

The positive pressure combustion mode is adopted in the furnace 5, and only a blower or an induced draft fan can be configured in the system. It is preferred in the present invention that a positive pressure combustion mode is adopted in the furnace 5, and only a blower fan can be configured in the system, or an induced draft fan can not be configured. Strengthen the combustion in the furnace, in order to reduce the power consumption of the system, reduce power consumption and initial investment cost.

The shape of the heat exchange tube I26 and the heat exchange tube II32 is not limited, and the present invention is preferably a spiral finned tube, which increases the heating area during heat energy exchange and reduces the volume of the equipment.

The heat exchange tube I26, heat exchange tube II32 and side plate 35 of the economizer 17 are made of ND steel, Corten steel or austenitic stainless steel, which can effectively reduce low temperature corrosion and prolong the service life of the low temperature heating equipment.

The convection tube bundle 38 is composed of at least one light tube. The arrangement of the tubes in the tube group generally adopts parallel or staggered arrangement. The present invention preferably adopts the parallel arrangement, which can effectively reduce the resistance of the flue gas, reduce the power consumption of the blower and reduce the consumption of natural gas. air supply pressure.

The turning flue 16 is a hollow frame structure surrounded by four steel plates, and the horizontal projection is a 90° elbow, which is conducive to the arrangement of the economizer 17 and the condenser 18, and reduces the overall equipment site occupation.

Further, the left membrane water-cooled wall 36 is provided with a fire hole 14; an explosion-proof door 19 is installed near the furnace outlet above the furnace of the left membrane water wall 36, and the fire hole can conveniently observe the combustion situation in the furnace, which is convenient for the staff Control the boiler; select the location of the explosion-proof door to prevent it from overheating, and at the same time facilitate the leakage of smoke to the outside of the boiler room to ensure the personal safety of the staff.

A maintenance platform 4 is provided below the burner 3 to facilitate boiler combustion control and maintenance of the burner.

Working principle: The return water of the primary pipe network enters the economizer 17 and the return water of the secondary pipe network enters the condenser 18 to cool the flue gas in stages. The return water temperature of the primary pipe network is 70~90°C, and the return water of the secondary pipe network The temperature is 35~45°C, the water and high-temperature flue gas of the primary pipe network pass through the heat exchange tube I26, the front membrane water cooling wall 6, the rear membrane water cooling wall 13, the left membrane water cooling wall 36, and the middle membrane water cooling wall 37. The convection tube bundle 38 performs countercurrent heat exchange to cool the flue gas to 80~120°C, and the secondary pipe network return water and high-temperature flue gas pass through the heat exchange tube II 32 of the condenser 18 for countercurrent heat exchange to cool the flue gas to 45°C ~55°C.

Claims (8)

1. A membrane-type water-cooled wall composite return water condensing natural gas hot water boiler, including an upper drum (8), a lower drum (2), a furnace (5), a turning flue (16), and an economizer (17) , condenser (18), convection tube bundle (38) and pipelines, safety valves (9), gas collection tanks (10), body inlet pipes (11 ), it is characterized in that the gas collection tank (10) is connected to the primary pipe network water supply pipe (21) of the pipeline; the return water of the primary pipe network return water pipe (20) of the pipeline passes through the lower water collection of the economizer (17) Box (28), lower header (27), heat exchange tube I (26), upper header (25), upper water header (24), rear membrane water wall (13) of furnace (5), The middle partition wall membrane water wall (37), the left membrane water wall (36), the front membrane water wall (6), the convection tube bundle (38), and finally communicate with the upper drum (8); the convection tube bundle (38) The upper end is connected to the upper drum (8), the lower end is connected to the lower drum (2), one end of the turning flue (16) is connected to the convection tube bundle (38), and the other end is connected to the flue gas inlet of the economizer (17) , the flue gas outlet of the economizer (17) is connected with the flue gas inlet of the condenser (18), and the flue gas outlet of the condenser (18) is connected with the chimney; the side wall (30) is attached to the upper header (25), the lower The header (27), four steel plates on the outside of the heat exchange tube I (26) are surrounded; one end of the side wall (30) is connected to the turning flue (16), and the other end is connected to the side plate (35) of the condenser (18). ) connection; the pipeline also includes a secondary pipe network water return pipe (22), a secondary pipe network water supply pipe (23), and the return water of the secondary pipe network return water pipe (22) passes through the points of the condenser (18) successively Water header (31), heat exchange tube II (32), water header (33); one end of the water header (33) is connected with the secondary pipe network water supply pipe (23), and the other end is blocked. 2. A membrane-type water-cooled wall composite return water condensing natural gas hot water boiler according to claim 1, characterized in that, the rear membrane-type water-cooled wall (13), the middle partition wall membrane-type water-cooled wall (37 ), the left membrane water wall (36), and the front membrane water wall (6) are all welded by pipes and flat steel, and thermal insulation cotton is laid on the outside of the membrane water wall. 3. A membrane-type water-cooled wall compound return water condensing natural gas hot water boiler according to claim 1 or 2, characterized in that, the heat exchange tube I (26) and the heat exchange tube II (32) are Spiral finned tubes. 4. A membrane-type water-cooled wall composite return water condensing natural gas hot water boiler according to claim 3, characterized in that the heat exchange tube I (26) and heat exchange tube II (32) of the economizer (17) , The side plate (35) is made of ND steel, Corten steel or austenitic stainless steel. 5. A membrane-type water-cooled wall compound return water condensing natural gas hot water boiler according to claim 1 or 2, characterized in that, the convection tube bundle (38) is composed of at least one bare tube, and in the tube group The arrangement of the tubes is in sequence. 6. A membrane water wall composite return water condensing natural gas hot water boiler according to claim 5, characterized in that the turning flue (16) is a hollow frame structure surrounded by four steel plates, horizontal The projection is a 90° elbow. 7. A membrane-type water-cooled wall compound return water condensing natural gas hot water boiler according to claim 6, characterized in that, the left membrane-type water-cooled wall (36) is provided with a fire viewing hole (14); An explosion-proof door (19) is installed near the furnace outlet position above the furnace of the formula water wall (36). 8. A membrane-type water-cooled wall compound return water condensing natural gas hot water boiler according to claim 7, characterized in that a maintenance platform (4) is provided below the burner (3).