External heat exchange system for water supply of flue gas waste heat boiler of float glass melting furnace

Abstract

The utility model discloses a float glass melting furnace flue gas waste heat boiler water supply external heat exchange system which comprises a boiler, a steam drum connected with the boiler through a pipeline and a water supply mechanism connected with the steam drum through a pipeline, a water outlet of the water supply mechanism is connected with a water inlet of the boiler through a pipeline, and the boiler comprises a coal economizer set. A water inlet of the coal economizer set is communicated with a water outlet of the water supply mechanism through a coal economizer water inlet pipe, a water outlet of the coal economizer set is communicated with the steam pocket through a coal economizer water outlet pipe, and a heat exchange mechanism used for increasing the temperature of the water inlet of the coal economizer set is connected between the coal economizer water inlet pipe and the coal economizer water outlet pipe. By means of the heat exchange mechanism, the phenomena that due to the fact that the water inlet temperature of the economizer is too low, the temperature of flue gas at the tail of the waste heat boiler is too large in decreasing amplitude, acid media in the flue gas are condensed at low temperature and attached to the outer surface of a heat exchange pipeline of the economizer, the pipeline is corroded, and the evaporator bursts and shuts down are effectively avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler waste heat recovery and utilization, in particular to an external heat exchange system for water supply of a float glass melting furnace flue gas waste heat boiler. Background Art

[0002] There are two systems running in the flue gas waste heat boiler of the float glass melting furnace, namely the flue gas system and the steam-water system. In the flue gas system, the high-temperature flue gas system is converted into low-temperature flue gas after heat exchange in the flue gas waste heat boiler of the float glass melting furnace and discharged. In the steam-water system, the condensate from the steam turbine generator set and the prepared desalted water enter the waste heat boiler deaerator for heating and deoxygenation. The heated and deoxygenated feed water is pressurized by the feed water pump and enters the high and low temperature economizer to recover the flue gas waste heat. After heating, it enters the steam drum and then enters the corresponding evaporator through the downcomers of the first, second, third, fourth, fifth and sixth evaporators respectively. After absorbing the flue gas heat through the heat exchange pipes of the evaporator and recovering the flue gas waste heat, the feed water becomes a steam-water mixture and returns to the steam drum through the risers of each evaporator. The saturated steam passes through the steam-water separator at the top of the steam drum and enters the low temperature superheater. After the feed water spray is cooled, it enters the high temperature superheater and continues to heat up. Finally, it becomes 2.5Mpa, 425℃ superheated steam through the main steam pipe to enter the steam turbine generator set for power generation. The exhaust steam after power generation is condensed and becomes condensate and returns to the boiler. The flue gas system and the steam-water system interact to form the operation of the boiler.

[0003] In the above boiler system, when the heated and deoxygenated feed water enters the economizer after being pressurized by the feed water pump, the water temperature is low, resulting in an excessive drop in the temperature of the flue gas at the tail of the waste heat boiler. The acidic medium in the flue gas will adhere to the outer surface of the economizer heat exchange pipe due to low-temperature condensation, corroding the pipe, and even causing the evaporator to burst and the boiler to stop in severe cases. Utility Model Content

[0004] The purpose of the utility model is to solve the shortcomings of the above-mentioned background technology and provide an external heat exchange system for feed water of waste heat boiler of flue gas of float glass melting furnace which can effectively heat the feed water temperature entering the economizer, prevent the flue gas temperature at the tail of the waste heat boiler from dropping too much, and prevent the acidic medium in the flue gas from adhering to the outer surface of the economizer heat exchange pipe due to low temperature condensation, thereby avoiding pipe corrosion and evaporator tube burst and furnace shutdown.

[0005] To achieve this purpose, the utility model is designed to provide an external heat exchange system for water supply of a flue gas waste heat boiler of a float glass melting furnace, comprising a boiler, a steam drum connected to the boiler through a pipeline, and a water supply mechanism connected to the steam drum through a pipeline, wherein a water outlet of the water supply mechanism is connected to a water inlet of the boiler through a pipeline, the boiler comprises an economizer group, the water inlet of the economizer group is connected to a water outlet of the water supply mechanism through an economizer water inlet pipe, the water outlet of the economizer group is connected to the steam drum through an economizer water outlet pipe, and a heat exchange mechanism for increasing the water inlet temperature of the economizer group is connected between the economizer water inlet pipe and the economizer water outlet pipe.

[0006] Furthermore, the heat exchange mechanism includes a heat exchanger, a first circulation pipeline is connected between the heat exchanger and the economizer water outlet pipe, and a second circulation pipeline is connected between the heat exchanger and the economizer water inlet pipe.

[0007] Furthermore, the first circulation pipeline includes a first valve connected to the economizer outlet pipe, the heat exchanger includes two heat source pipeline interfaces, namely a first heat source pipeline interface and a second heat source pipeline interface, a heat source water inlet pipe is connected between the water inlet of the first valve and the first heat source pipeline interface, and a heat source water outlet pipe is connected between the water outlet of the first valve and the second heat source pipeline interface.

[0008] Furthermore, a heat source water inlet valve is connected to the heat source water inlet pipe.

[0009] Furthermore, a heat source water outlet valve is connected to the heat source water outlet pipe.

[0010] Furthermore, the second circulation pipeline includes a second valve connected to the economizer water inlet pipe, the heat exchanger includes two cold source pipe interfaces, namely a first cold source pipe interface and a second cold source pipe interface, a cold source water inlet pipe is connected between the water inlet of the second valve and the first cold source pipe interface, and a cold source water outlet pipe is connected between the water outlet of the second valve and the second cold source pipe interface.

[0011] Furthermore, a cold source water inlet valve is connected to the cold source water inlet pipe.

[0012] Furthermore, a cold source water outlet valve is connected to the cold source water outlet pipe.

[0013] Furthermore, the economizer group includes a plurality of economizers arranged in front and behind the flue gas outlet of the boiler along the flow direction of the flue gas.

[0014] Furthermore, the water supply mechanism includes a deaerator connected to the steam drum through a pipeline and a water pump connected to the water outlet of the deaerator through a pipeline, and the water outlet of the water pump is connected to the water inlet of the economizer group through the economizer water inlet pipe.

[0015] The beneficial effect of the utility model is that by closing the first valve and the second valve, the water heated by the economizer enters the heat exchanger through the first circulation pipeline, and at the same time, the water in the economizer water inlet pipe also enters the heat exchanger through the second circulation pipeline, and the water heated by the economizer heats the economizer water inlet, thereby increasing the economizer water inlet temperature. It effectively avoids the excessive drop in the flue gas temperature at the tail of the waste heat boiler due to the economizer water inlet temperature being too low, causing the acidic medium in the flue gas to condense at low temperature and adhere to the outer surface of the economizer heat exchange pipe, corroding the pipe, and causing the evaporator tube to burst and stop the furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of an external heat exchange system for feeding water to a flue gas waste heat boiler of a float glass melting furnace designed for the utility model;

[0017] Among them, 1 is a boiler, 2 is a steam drum, 3 is an economizer group, 4 is an economizer water inlet pipe, 5 is an economizer water outlet pipe, 6 is a heat exchanger, 7 is a first valve, 8 is a first heat source pipeline interface, 9 is a second heat source pipeline interface, 10 is a heat source water inlet pipe, 11 is a heat source water outlet pipe, 12 is a heat source water inlet valve, 13 is a heat source water outlet valve, 14 is a second valve, 15 is a first cold source pipeline interface, 16 is a second cold source pipeline interface, 17 is a cold source water inlet pipe, 18 is a cold source water outlet pipe, 19 is a cold source water inlet valve, 20 is a cold source water outlet valve, 21 is a deaerator, and 22 is a water pump. DETAILED DESCRIPTION

[0018] The utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0019] like Figure 1 The external heat exchange system for water supply of flue gas waste heat boiler of float glass melting furnace shown in the figure comprises a boiler 1, a steam drum 2 connected to the boiler 1 through a pipeline, and a water supply mechanism connected to the steam drum 2 through a pipeline, the water supply mechanism comprises a deaerator 21 connected to the steam drum 2 through a pipeline and a water pump 22 connected to the water outlet of the deaerator 21 through a pipeline, the water outlet of the water pump is connected to the water inlet of the boiler 1 through a pipeline, the boiler 1 comprises an economizer group 3, the economizer group 3 comprises a plurality of economizers arranged front and back along the flow direction of the flue gas at the flue gas outlet of the boiler 1, the water inlet of the economizer group 3 is connected to the water outlet of the water pump through an economizer water inlet pipe 4, the water outlet of the economizer group 3 is connected to the steam drum 2 through an economizer water outlet pipe 5, and a heat exchange mechanism for increasing the water inlet temperature of the economizer group 3 is connected between the economizer water inlet pipe 4 and the economizer water outlet pipe 5.

[0020] The heat exchange mechanism includes a heat exchanger 6, which is preferably an external surface heat exchanger. A first circulation pipeline is connected between the heat exchanger 6 and the economizer water outlet pipe 5, and a second circulation pipeline is connected between the heat exchanger 6 and the economizer water inlet pipe 4.

[0021] The first circulation pipeline includes a first valve 7 connected to the economizer outlet pipe 5, and the heat exchanger 6 includes two heat source pipeline interfaces, namely a first heat source pipeline interface 8 and a second heat source pipeline interface 9. A heat source water inlet pipe 10 is connected between the water inlet of the first valve 7 and the first heat source pipeline interface 8, a heat source water outlet pipe 11 is connected between the water outlet of the first valve 7 and the second heat source pipeline interface 9, a heat source water inlet valve 12 is connected to the heat source water inlet pipe 10, and a heat source water outlet valve 13 is connected to the heat source water outlet pipe 11.

[0022] The second circulation pipeline includes a second valve 14 connected to the economizer water inlet pipe 4, the heat exchanger 6 includes two cold source pipeline interfaces, namely a first cold source pipeline interface 15 and a second cold source pipeline interface 16, a cold source water inlet pipe 17 is connected between the water inlet of the second valve 14 and the first cold source pipeline interface 15, a cold source water outlet pipe 18 is connected between the water outlet of the second valve 14 and the second cold source pipeline interface 16, a cold source water inlet valve 19 is connected to the cold source water inlet pipe 17, and a cold source water outlet valve 20 is connected to the cold source water outlet pipe 18.

[0023] The principle of the utility model is to use the outlet water of the economizer group 3 at about 220°C to heat the inlet water of the economizer group 3 at 133°C-138°C. The working method of the external heat exchange system for the water supply of the flue gas waste heat boiler of the float glass melting furnace designed by the utility model is: when the inlet water temperature of the economizer group 3 is normal, keep the first valve 7 and the second valve 14 open, the heat source water inlet valve 12, the heat source water outlet valve 13, the cold source water inlet valve 19 and the cold source water outlet valve 20 closed, and the external heat exchange system does not work; when the inlet water temperature of the economizer group 3 is lower than 180°C, close the first valve 7 and the second valve 14, open the heat source water inlet valve 12, the heat source water outlet valve 13, the cold source water inlet valve 19 and the cold source water outlet valve 20, and all the water entering the economizer group 3 needs to be heated by the heat exchanger 6 before entering the economizer group 3, ensuring that the inlet water temperature of the economizer group 3 will not be too low.

[0024] In summary, the utility model closes the first valve 7 and the second valve 14, so that the water heated by the economizer enters the heat exchanger 6 through the first circulation pipeline. At the same time, the water in the economizer water inlet pipe 4 also enters the heat exchanger 6 through the second circulation pipeline, and the water heated by the economizer heats the economizer water inlet, thereby increasing the economizer water inlet temperature. This effectively avoids the excessive drop in the flue gas temperature at the tail of the waste heat boiler due to the economizer water inlet temperature being too low, causing the acidic medium in the flue gas to condense at low temperature and adhere to the outer surface of the economizer heat exchange pipe, corroding the pipe, and causing the evaporator tube to burst and stop the furnace.

[0025] The above is only a preferred embodiment of the utility model, and does not limit the structure of the utility model in any form. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model still falls within the scope of the technical solution of the utility model.

Claims

1. An external heat exchange system for water supply of a flue gas waste heat boiler of a float glass melting furnace, comprising a boiler (1), a steam drum (2) connected to the boiler (1) through a pipeline, and a water supply mechanism connected to the steam drum (2) through a pipeline, wherein a water outlet of the water supply mechanism is connected to a water inlet of the boiler (1) through a pipeline, and characterized in that: The boiler (1) comprises an economizer group (3), the water inlet of the economizer group (3) is connected to the water outlet of the water supply mechanism via an economizer water inlet pipe (4), the water outlet of the economizer group (3) is connected to the steam drum (2) via an economizer water outlet pipe (5), and a heat exchange mechanism for increasing the water inlet temperature of the economizer group (3) is connected between the economizer water inlet pipe (4) and the economizer water outlet pipe (5).

2. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace according to claim 1, characterized in that: The heat exchange mechanism comprises a heat exchanger (6), a first circulation pipeline is connected between the heat exchanger (6) and the economizer water outlet pipe (5), and a second circulation pipeline is connected between the heat exchanger (6) and the economizer water inlet pipe (4).

3. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace according to claim 2, characterized in that: The first circulation pipeline comprises a first valve (7) connected to the economizer outlet pipe (5); the heat exchanger (6) comprises two heat source pipeline interfaces, namely a first heat source pipeline interface (8) and a second heat source pipeline interface (9); a heat source water inlet pipe (10) is connected between the water inlet of the first valve (7) and the first heat source pipeline interface (8); and a heat source water outlet pipe (11) is connected between the water outlet of the first valve (7) and the second heat source pipeline interface (9).

4. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace as claimed in claim 3, characterized in that: The heat source water inlet pipe (10) is connected to a heat source water inlet valve (12).

5. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace as claimed in claim 3, characterized in that: The heat source water outlet pipe (11) is connected to a heat source water outlet valve (13).

6. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace according to claim 2 or 3, characterized in that: The second circulation pipeline comprises a second valve (14) connected to the economizer water inlet pipe (4); the heat exchanger (6) comprises two cold source pipe interfaces, namely a first cold source pipe interface (15) and a second cold source pipe interface (16); a cold source water inlet pipe (17) is connected between the water inlet of the second valve (14) and the first cold source pipe interface (15); and a cold source water outlet pipe (18) is connected between the water outlet of the second valve (14) and the second cold source pipe interface (16).

7. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace according to claim 6, characterized in that: The cold source water inlet pipe (17) is connected to a cold source water inlet valve (19).

8. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace according to claim 6, characterized in that: The cold source water outlet pipe (18) is connected to a cold source water outlet valve (20).

9. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace according to claim 1, characterized in that: The economizer group (3) comprises a plurality of economizers arranged in front and behind each other at the flue gas outlet of the boiler (1) along the flow direction of the flue gas.

10. The external heat exchange system for feed water of flue gas waste heat boiler of float glass melting furnace according to claim 1, characterized in that: The water supply mechanism comprises a deaerator (21) connected to the steam drum (2) via a pipeline and a water pump (22) connected to the water outlet of the deaerator (21) via a pipeline, and the water outlet of the water pump (22) is connected to the water inlet of the economizer group (3) via the economizer water inlet pipe (4).

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