Deoxidizing and steam supplementing pipeline system of low-pressure steam drum of waste heat boiler

Abstract

The utility model relates to a deoxidizing and steam supplementing pipeline system of a low-pressure steam drum of a waste heat boiler, and belongs to the technical field of boiler equipment. The device comprises a deoxidizing head connected with a low-pressure steam pocket, a deoxidizing and steam supplementing pipeline with an outlet connected with the deoxidizing head, and a regulating valve arranged on the deoxidizing and steam supplementing pipeline, wherein an inlet of the deoxidizing and steam supplementing pipeline is connected with a high-pressure steam pocket. The system has the advantages of being low in equipment cost and operation power consumption, avoiding the situations that auxiliary steam is wasted and normal operation of a unit is affected, being simple in control logic, convenient and fast to operate, capable of controlling connection or disconnection of the deoxidizing and steam supplementing pipeline through the adjusting valve according to the operation situation of the waste heat boiler, and safe and reliable.

Description

Technical Field

[0001] The utility model relates to a deoxidation and steam supplementation pipeline system of a low-pressure drum of a waste heat boiler, belonging to the technical field of boiler equipment. Background Art

[0002] In the past decade, gas turbine power generation technology has made great progress. Gas-steam combined cycle units have gradually become an important development direction of the world's power industry with their advantages of high efficiency, low emissions, and flexible operating characteristics. More and more combined cycle units have been put into the market. At present, many combined cycle power plant waste heat boilers require the installation of a supplementary combustion system to increase the high-pressure main steam production. However, when the amount of supplementary combustion is large, the low-pressure main steam will drop sharply to the steam production in the low-pressure drum, which cannot meet the deoxygenation needs of the deaerator head itself. In another case, many gas turbines use fuels with high sulfur content (such as steelmaking exhaust, light oil, and heavy oil). The increase in sulfur content causes the flue gas acid dew point temperature to increase. In order to prevent acid corrosion on the rear heating surface, it is usually necessary to bypass all condensate into the low-pressure drum, which will also cause the low-pressure main steam to drop sharply, making the steam production of the low-pressure drum unable to meet the deoxygenation needs of the deaerator head itself. In order to solve the normal deoxygenation problem of the waste heat boiler in the above situation, it is usually adopted to supplement auxiliary steam from the outside of the waste heat boiler to meet the deoxygenation steam needs of the deaerator head. The existing solutions are as follows Figure 1 As shown: an external steam source 8 for producing auxiliary steam is added, and the external steam source 8 is connected to a deoxygenation steam supply pipeline 6 for transmitting auxiliary steam. When the low-pressure main steam cannot meet the deoxygenation demand of the deoxygenation head, the deoxygenation head 4 is supplemented with auxiliary steam from the external steam source 8 through the deoxygenation steam supply pipeline 6 for deoxygenation. A regulating valve 2 for controlling the flow rate of auxiliary steam is provided on the deoxygenation steam supply pipeline 6. However, this deoxygenation steam supply solution still has the following defects:

[0003] (1) An additional external steam source 8 is required to produce auxiliary steam, which increases the complexity of the equipment, resulting in increased equipment costs and increased auxiliary power consumption;

[0004] (2) In order to ensure the deoxidation steam for the deoxidation head 4, the external steam source 8 needs to be operated synchronously with the waste heat boiler. If the steam produced in the low-pressure drum 3 can meet the deoxidation demand of the deoxidation head 4 itself without auxiliary steam, the auxiliary steam will be wasted;

[0005] (3) The operating risk of the unit is increased. Once the external steam source 8 fails, the waste heat boiler will inevitably need to stop operating, affecting the normal operation of the entire unit. Summary of the invention

[0006] The utility model mainly solves the technical problems in the prior art that the deoxygenation and steam supply piping system is complex, resulting in high equipment cost and affecting the stable operation of the unit, and provides a deoxygenation and steam supply piping system for the low-pressure drum of a waste heat boiler with a simple piping system and stable operation.

[0007] The utility model solves the above technical problems mainly through the following technical solutions: the utility model includes a deaerator head connected to the low-pressure steam drum, a deaerator steam supply pipeline whose outlet is connected to the deaerator head, and a regulating valve arranged on the deaerator steam supply pipeline, characterized in that the inlet of the deaerator steam supply pipeline is connected to the high-pressure steam drum.

[0008] Preferably, it also includes a pressure transmitter arranged on the deaerator head, and a regulating valve controller electrically connected to the pressure transmitter, the pressure transmitter monitors the pressure in the deaerator head and sends an electrical signal, and the regulating valve controller controls the opening of the regulating valve according to the electrical signal sent by the pressure transmitter.

[0009] Preferably, the regulating valve is an electric regulating valve.

[0010] The utility model has a simple structure and has the following advantages:

[0011] (1) Since the deoxygenation supplementary steam of the low-pressure drum comes from the high-pressure drum of the unit itself, the unit does not need to be equipped with additional auxiliary steam for deoxygenation, which reduces the equipment cost and operating power consumption of the unit, and avoids the waste of auxiliary steam and the impact of auxiliary steam equipment failure on the normal operation of the unit in the prior art;

[0012] (2) When the equipment is running, the opening of the regulating valve can be controlled according to the monitoring signal of the pressure transmitter, and the steam flow of deoxygenation and steam replenishment on the pipeline can be flexibly adjusted. The system control logic is simple and the operation is convenient;

[0013] (3) The deaeration and steam supply pipeline can be opened or closed by regulating valves according to the operation status of the waste heat boiler, and the system is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 It is a schematic diagram of the prior art;

[0015] Attached Figure 2 It is a schematic diagram of a preferred embodiment of the utility model.

[0016] Explanation of the reference numerals: 1. High-pressure steam drum; 2. Control valve; 3. Low-pressure steam drum; 4. Deaerator head; 5. Pressure transmitter; 6. Deaerator and steam supply pipeline; 7. Control valve controller; 8. External steam source. DETAILED DESCRIPTION

[0017] The technical solution of the utility model is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0018] Embodiment 1: As attached Figure 2 As shown, the utility model includes a high-pressure steam drum 1, a regulating valve 2, a low-pressure steam drum 3, a deaerator head 4, a pressure transmitter 5, and a deaerator steam supply pipeline 6 connecting the high-pressure steam drum 1 and the deaerator head 4;

[0019] The regulating valve 2 adopts an electric regulating valve;

[0020] The pressure transmitter 5 is installed on the deaerator head 4, and is used to monitor the working fluid pressure in the deaerator head 4 and send an electrical signal;

[0021] The regulating valve controller 7 receives the electrical signal sent by the pressure transmitter 5 and sends a control signal to the electric actuator of the regulating valve 2 , thereby controlling the opening of the regulating valve 2 through the electric actuator.

[0022] When the waste heat boiler is running, the pressure transmitter 5 monitors the steam pressure in the deaerator head 4. When the value of the monitoring data of the pressure transmitter 5 is greater than or equal to the set value, it means that the steam production in the low-pressure drum 3 can meet the deaerator head 4's own deoxygenation needs, and there is no need to supplement steam from the high-pressure drum 1. The regulating valve controller 7 controls the regulating valve 2 to close according to the electrical signal sent by the pressure transmitter 5. When the value of the monitoring data of the pressure transmitter 5 is lower than the set value, it means that the steam production in the low-pressure drum 3 cannot meet the deaerator head 4's own deoxygenation needs, and the high-pressure drum 1 is needed to supplement steam. At this time, the regulating valve controller 7 controls the regulating valve 2 to close according to the electrical signal sent by the pressure transmitter 5. The throttle controller 7 controls the regulating valve 2 according to the electrical signal sent by the pressure transmitter 5. The regulating valve 2 is opened and the opening degree gradually increases. At this time, the steam from the high-pressure drum 1 enters the deaerator head 4 through the deaerator steam supply pipeline 6. The steam pressure in the deaerator head 4 gradually increases, and the value of the monitoring data of the pressure transmitter 5 also gradually increases. When the value of the monitoring data of the pressure transmitter 5 reaches the set value, the regulating valve controller 7 controls the regulating valve 2 to maintain its opening degree, so that the deaerator head 4 can continuously obtain the supplementary steam from the high-pressure drum 1 for deoxidation, so that the low-pressure drum 3 can operate stably.

[0023] In the utility model, the pressure transmitter 5 sends an electrical signal to the regulating valve controller 7, the regulating valve controller 7 performs data processing according to the set parameters and logic, and then outputs the corresponding control signal to the electric actuator of the regulating valve 2. The electric actuator controls the up and down movement of the valve core of the regulating valve 2 according to the size and direction of the control signal, thereby realizing the control and adjustment of the opening and closing of the regulating valve 2 and the valve opening.

[0024] Of course, the above drawings and embodiments are only used to explain and illustrate the utility model, and cannot be used as an improper limitation of the utility model. Any technical solutions obtained by those skilled in the art making equivalent adjustments and changes based on the utility model fall within the protection scope of the utility model.

Claims

1. A deoxidation and steam supply pipeline system for a low-pressure drum of a waste heat boiler, comprising a deoxidation header (4) connected to a low-pressure drum (3), a deoxidation and steam supply pipeline (6) whose outlet is connected to the deoxidation header (4), and a regulating valve (2) arranged on the deoxidation and steam supply pipeline (6). It is characterized in that The inlet of the deoxygenation and steam supply pipeline (6) is connected to the high-pressure steam drum (1).

2. The deoxidation and steam supply pipeline system of the low-pressure drum of a waste heat boiler according to claim 1, It is characterized in that It also includes a pressure transmitter (5) arranged on the deaerator head (4), and a regulating valve controller (7) connected to the pressure transmitter (5) by telecommunication, wherein the pressure transmitter (5) monitors the pressure of the working fluid in the deaerator head (4) and sends an electrical signal, and the regulating valve controller (7) controls the opening of the regulating valve (2) according to the electrical signal sent by the pressure transmitter (5).

3. The deoxidation and steam supply pipeline system of the low-pressure drum of a waste heat boiler according to claim 2, It is characterized in that The regulating valve (2) is an electric regulating valve.

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