Adjustable economizer system

Abstract

The utility model discloses an adjustable economizer system which comprises an economizer, a high-temperature steam inlet pipeline, a water supply inlet pipeline and an economizer outlet pipeline, the outlet end of the economizer is connected with the economizer outlet pipeline, the water supply inlet pipeline is divided into two pipelines, one pipeline is connected with the economizer outlet pipeline to form an economizer bypass, and the other pipeline is connected with the high-temperature steam inlet pipeline. The high-temperature steam inlet pipeline is connected with the inlet end of the economizer through a pipeline, and flow adjusting devices are installed on the economizer bypass, the connecting pipeline of the water supply inlet pipeline and the economizer and the connecting pipeline of the high-temperature steam inlet pipeline and the economizer respectively. According to the high-efficiency adjustable coal economizer, the coal economizer, the coal economizer bypass, the water supply inlet pipeline and the high-temperature steam inlet pipeline form a set of integral high-efficiency adjustable coal economizer system through the flow adjusting device; and the boiler exhaust gas temperature is controlled, and the corrosion problem caused by large-area gathering and covering of ammonium bisulfate of a coal economizer pipe is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of economizers, in particular to an adjustable economizer system. Background Art

[0002] When the boiler is in early operation or started up, the heating surfaces, especially the economizer, are relatively clean. There are problems such as relatively more hot surfaces, greater heat absorption by the economizer, and lower exhaust gas temperature.

[0003] After the boiler has been running for a period of time, ammonium bisulfate will be generated in the economizer due to the injection of SNCR or SCR into the furnace. Ammonium bisulfate is a white powder that will be adsorbed on the tube wall of the water-cooled wall after it is generated. Carbon black tail gas contains a large amount of moisture, which condenses on the low-temperature heating surface, and the soot adheres to the tube wall to form a wet ammonium bisulfate aggregation layer. The sticky surface formed can further promote the capture of fly ash, resulting in a large amount of ammonium bisulfate accumulating on the surface of the economizer. The corrosive sticky low-temperature ash adheres to the heating surface, affecting and aggravating the corrosion of the heating surface. The economizer is wrapped in wet ammonium bisulfate for a long time, resulting in large-scale corrosion. Because the surface of the economizer is covered with a large area of ​​ammonium bisulfate and corroded severely, the heating surface absorbs less heat, which ultimately leads to high exhaust temperature. Excessive or low exhaust temperature will affect the safe and stable combustion in the furnace. Utility Model Content

[0004] In order to solve the above technical problems, the utility model designs an adjustable economizer system.

[0005] The utility model adopts the following technical solutions:

[0006] An adjustable economizer system comprises an economizer, a high-temperature steam inlet pipe, a feed water inlet pipe, and an economizer outlet pipe. The economizer outlet end is connected to the economizer outlet pipe. The feed water inlet pipe is divided into two pipes, one of which is connected to the economizer outlet pipe to form an economizer bypass, and the other is connected to the economizer inlet end. The high-temperature steam inlet pipe is connected to the economizer inlet end through a pipeline. Flow regulating devices are respectively installed on the economizer bypass, the feed water inlet pipe and the economizer connecting pipe, and the high-temperature steam inlet pipe and the economizer connecting pipe.

[0007] Preferably, the economizer comprises a plurality of economizer tube groups, which are arranged in parallel. The inlet header of each economizer tube group is connected to the high-temperature steam inlet pipeline and the feed water inlet pipeline through connecting pipelines, and flow regulating devices are installed on the connecting pipelines. The outlet header of each economizer tube group is then connected to the economizer outlet pipeline.

[0008] Preferably, the economizer comprises economizer tube group 1 and economizer tube group 2.

[0009] Preferably, the flow regulating device adopts an electrically controlled regulating valve.

[0010] Preferably, temperature sensors are installed in the multiple economizer tube groups respectively to obtain the temperature of the economizer tube groups when they are dry-burned.

[0011] The working principle of the utility model is: when the heating surface is clean and the economizer area is relatively large, the economizer flow regulating device is closed or adjusted down, the working medium flowing through the economizer is appropriately reduced, the heat exchange is reduced, and the exhaust gas temperature is controlled within a reasonable range; when the economizer needs to be fully utilized, the bypass flow regulating device is closed, so that all the feed water can pass through the economizer, and the heat exchange effect is maximized; after the boiler has been running for a period of time, a large amount of ammonium bisulfate will adhere to the economizer tube wall, and the feed water flow regulating device of the corroded tube group is closed, so that the temperature of the corroded tube group is raised to above 350°C, and the ammonium bisulfate accumulated on the surface of the tube is completely decomposed. If the temperature of the tube group is lower than 350°C during dry burning, high-temperature steam is extracted from the superheater outlet pipe, and heat is exchanged with the tube segment in the economizer through the high-temperature steam inlet pipe, and the working temperature of the tube segment is heated to above 350°C. Thereby, the purpose of removing ammonium bisulfate, alleviating the corrosion of the heating surface, and controlling the exhaust gas temperature is achieved.

[0012] The beneficial effect of the utility model is that the utility model combines the economizer, economizer bypass, water supply inlet pipe and high-temperature steam inlet pipe into an overall high-efficiency adjustable economizer system through a flow regulating device, which can control the boiler exhaust temperature at different stages of boiler operation and solve the corrosion problem of the economizer pipe caused by large-area accumulation and coverage of ammonium bisulfate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the utility model;

[0014] In the figure: 1. economizer, 2. economizer tube group 1, 3. economizer tube group 2, 4. economizer bypass, 5. feed water inlet pipe, 6. high-temperature steam inlet pipe, 7. economizer outlet pipe, 8. regulating valve 1, 9. regulating valve 2, 10. regulating valve 3, 11. regulating valve 4, 12. regulating valve 5. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0016] Example: Figure 1As shown, an adjustable economizer system includes an economizer 1, a high-temperature steam inlet pipe 6, a feed water inlet pipe 5, and an economizer outlet pipe 7. The economizer outlet end is connected to the economizer outlet pipe. The feed water inlet pipe is divided into two pipes, one of which is connected to the economizer outlet pipe to form an economizer bypass 4, and the other is connected to the inlet end of the economizer. The high-temperature steam inlet pipe is connected to the inlet end of the economizer through a pipeline.

[0017] The economizer includes economizer tube group 1 2 and economizer tube group 2 3. The two economizer tube groups are arranged in parallel, and the inlet header of each economizer tube group is connected to the high-temperature steam inlet pipeline and the feed water inlet pipeline through connecting pipelines, and flow regulating devices are installed on the connecting pipelines, namely regulating valve 2 9, regulating valve 3 10, regulating valve 4 11 and regulating valve 5 12, and the outlet headers of the two economizer tube groups are then connected to the economizer outlet pipeline. A flow regulating device, namely regulating valve 1 8, is installed on the economizer bypass. Regulating valve 1, regulating valve 2, regulating valve 3, regulating valve 4 and regulating valve 5 can adjust the flow rate of the incoming working medium. Temperature sensors are installed in the two economizer tube groups respectively. It is used to obtain the temperature of the economizer tube group when it is dry-burned.

[0018] When the system is actually applied, it can be used in three different stages of boiler operation: when the boiler is in early operation or start-up, when the economizer needs to be fully utilized, and when the economizer tube group is corroded due to the adhesion of ammonium bisulfate.

[0019] When the boiler is in early operation or started up, reduce the economizer inlet pipeline flow regulating device, i.e. regulating valve 4 and regulating valve 5, open the economizer bypass flow regulating device, i.e. regulating valve 1, appropriately reduce the working fluid flowing through the economizer, reduce the heat exchange, so as to control the exhaust gas temperature within a reasonable range.

[0020] When the economizer needs to be fully utilized, close the economizer bypass flow control device, that is, regulating valve 1, and fully open the economizer inlet pipeline flow control device, that is, regulating valve 4 and regulating valve 5, so that all the feed water passes through the economizer and the heat exchange effect is maximized; when the economizer tube group 1 is corroded due to the attachment of ammonium bisulfate, close the flow control device of economizer tube group 1, that is, regulating valve 4, and open the flow control device of economizer tube group 2, that is, regulating valve 5, so that the tube group economizer tube group 1 is dry-burned, and the temperature rises to above 350℃. At this time, the ammonium bisulfate accumulated on the surface of the tube is completely decomposed. If the temperature of economizer tube group 1 is lower than 350℃ when it is dry-burned, open the flow control device of high-temperature steam entering economizer tube group 1, that is, regulating valve 2, and heat the working temperature of economizer tube group 1 to above 350℃. Thereby achieving the purpose of removing ammonium bisulfate, alleviating corrosion of the heating surface, and controlling the exhaust temperature.

[0021] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. An adjustable economizer system, comprising an economizer, a high-temperature steam inlet pipe, a feedwater inlet pipe, and an economizer outlet pipe, wherein the economizer outlet end is connected to the economizer outlet pipe, and is characterized in that: The water supply inlet pipe is divided into two pipes, one of which is connected to the economizer outlet pipe to form an economizer bypass, and the other is connected to the inlet end of the economizer. The high-temperature steam inlet pipe is connected to the inlet end of the economizer through a pipeline. Flow regulating devices are respectively installed on the economizer bypass, the water supply inlet pipe and the economizer connecting pipe, and the high-temperature steam inlet pipe and the economizer connecting pipe.

2. The adjustable economizer system according to claim 1, characterized in that: The economizer includes multiple economizer tube groups, which are distributed in parallel. The inlet header of each economizer tube group is connected to the high-temperature steam inlet pipeline and the feed water inlet pipeline through connecting pipelines, and flow regulating devices are installed on the connecting pipelines. The outlet header of each economizer tube group is then connected to the economizer outlet pipeline.

3. The adjustable economizer system according to claim 2, characterized in that: The economizer includes economizer tube group 1 and economizer tube group 2.

4. An adjustable economizer system according to claim 1 or 2, characterized in that: The flow regulating device adopts an electrically controlled regulating valve.

5. The adjustable economizer system according to claim 2, characterized in that: Temperature sensors are respectively installed in the multiple economizer tube groups.

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