A structure and method for maintaining the operation of a steam-driven water supply pump under low load conditions

Abstract

The present invention provides a structure and method for maintaining the operation of a steam-driven feedwater pump under low-load conditions, which solves the problem that the steam-driven feedwater pump cannot operate under low-load conditions. The steam-driven feedwater pump exhaust pipe is connected to the steam-driven feedwater pump; one end of the low-pressure steam pipe is connected to the steam-driven feedwater pump exhaust pipe, and the other end is connected to the pressure matcher; the No. 1 electric valve and the No. 1 check valve are installed on the low-pressure steam pipe; the medium-pressure driving steam pipe is connected to the pressure matcher; the No. 2 electric valve is installed on the medium-pressure driving steam pipe; one end of the pressure matcher exhaust pipe is connected to the pressure matcher, and the other end is connected to the high-pressure deaerator; the safety valve, the No. 3 electric valve, and the No. 2 check valve are all installed on the pressure matcher exhaust pipe.

Description

Technical Field

[0001] The invention relates to a structure and method for maintaining the operation of a steam-driven water supply pump under low-load conditions. Background Art

[0002] In cogeneration projects, steam-driven feedwater pumps are a commonly used auxiliary equipment. Their exhaust steam is often used to heat low-pressure deaerators (mostly atmospheric deaerators). The normal operation of this equipment can effectively reduce the power consumption rate of the plant and improve the economic efficiency of the whole plant operation. In actual operation, the thermal load of some cogeneration projects fluctuates greatly. Under low-load conditions, the steam consumption of the low-pressure deaerator for heating steam is too low, which will cause the steam-driven feedwater pump to fail to operate normally. In order to solve this technical difficulty, in actual operation, it is currently solved by frequently starting and stopping the pump, which undoubtedly increases the workload of the operators, and the frequent start and stop causes great loss to the equipment, and the economic efficiency of the whole plant operation is also poor. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a structure and method with a reasonable structural design for maintaining the operation of a pneumatic water supply pump under low-load conditions, thereby solving the problem that the pneumatic water supply pump cannot operate under low-load conditions.

[0004] The technical solution adopted by the present invention to solve the above-mentioned problem is: a structure for maintaining the operation of a steam-driven feedwater pump under low-load conditions, comprising a steam-driven feedwater pump, a high-pressure deaerator and a steam-driven feedwater pump exhaust pipe; the steam-driven feedwater pump exhaust pipe is connected to the steam-driven feedwater pump; it is characterized in that it also includes a low-pressure steam pipe, a No. 1 electric valve, a No. 1 check valve, a medium-pressure driving steam pipe, a No. 2 electric valve, a pressure matcher, a pressure matcher exhaust pipe, a safety valve, a No. 3 electric valve, a No. 2 check valve and a high-pressure deaerator; one end of the low-pressure steam pipe is connected to the steam-driven feedwater pump exhaust pipe, and the other end is connected to the pressure matcher; the No. 1 electric valve and the No. 1 check valve are installed on the low-pressure steam pipe; the medium-pressure driving steam pipe is connected to the pressure matcher; the No. 2 electric valve is installed on the medium-pressure driving steam pipe; one end of the pressure matcher exhaust pipe is connected to the pressure matcher, and the other end is connected to the high-pressure deaerator; the safety valve, the No. 3 electric valve and the No. 2 check valve are all installed on the pressure matcher exhaust pipe.

[0005] The steam-driven feedwater pump exhaust pipe of the present invention is provided with a temperature measuring point and a pressure measuring point.

[0006] The No. 1 electric valve and the No. 2 electric valve described in the present invention are both electric gate valves.

[0007] The No. 3 electric valve described in the present invention is an electric stop valve.

[0008] A method for maintaining the operation of a steam-driven water supply pump under low-load conditions, using the structure for maintaining the operation of a steam-driven water supply pump under low-load conditions, comprises the following steps:

[0009] Under normal working conditions, the No. 1 electric valve, No. 2 electric valve and No. 3 electric valve are closed, and the exhaust steam of the steam-driven feedwater pump enters the low-pressure deaerator through the steam-driven feedwater pump exhaust pipe and is only used to heat the low-pressure deaerator; the heating steam for the high-pressure deaerator is provided by the heating steam in the plant, and the pressure matching device does not operate at this time;

[0010] When the heat load is low to a certain extent, the steam consumption of the low-pressure deaerator for heating steam is too low. When the exhaust pressure of the steam-driven feedwater pump rises to a certain set value, the No. 1 electric valve, No. 2 electric valve and No. 3 electric valve are opened to open the medium-pressure heating steam in the plant. The steam enters the pressure matcher through the medium-pressure driven steam pipeline. The pressure matcher draws the low-pressure steam discharged by the steam-driven feedwater pump. The matched steam enters the high-pressure deaerator through the pressure matcher exhaust pipeline and is used to heat the high-pressure deaerator, thereby increasing the steam consumption of the steam-driven feedwater pump.

[0011] The set value described in the present invention is set according to the parameters provided by the steam-driven water supply pump manufacturer.

[0012] Compared with the prior art, the present invention has the following advantages and effects: the present invention utilizes the medium-pressure steam in the plant to draw the back-pressure exhaust steam of the steam-driven pump to reach a certain pressure to heat the high-pressure deaerator, thereby increasing the steam consumption of the steam-driven pump, thereby solving the problem that the steam-driven feedwater pump cannot operate under low-load conditions. The present invention is conducive to the stable operation of the system, can maintain the operation of the steam-driven pump, can reduce the power consumption rate of the plant and improve the economic efficiency of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0015] See also Figure 1 The embodiment of the present invention includes a steam-driven feedwater pump 1, a steam-driven feedwater pump exhaust pipe 2, a pressure measuring point 3, a temperature measuring point 4, a low-pressure steam pipe 5, a No. 1 electric valve 6, a No. 1 check valve 7, a medium-pressure driving steam pipe 8, a No. 2 electric valve 9, a pressure matcher 10, a pressure matcher exhaust pipe 11, a safety valve 12, a high-pressure deaerator 13, a No. 3 electric valve 14 and a No. 2 check valve 15.

[0016] The steam-driven feedwater pump exhaust pipe 2 is connected to the steam-driven feedwater pump 1 , and the steam-driven feedwater pump 1 is connected to the low-pressure deaerator through the steam-driven feedwater pump exhaust pipe 2 .

[0017] A temperature measuring point 4 and a pressure measuring point 3 are provided on the exhaust pipe 2 of the steam-driven feedwater pump.

[0018] One end of the low-pressure steam pipe 5 is connected to the steam-driven feedwater pump exhaust pipe 2 , and the other end is connected to the pressure matcher 10 .

[0019] The No. 1 electric valve 6 and the No. 1 check valve 7 are installed on the low-pressure steam pipeline 5. The No. 1 electric valve 6 is interlocked and stopped or manually controlled according to the set value of the temperature and pressure measuring point on the steam-driven feedwater pump exhaust pipeline 2, and the No. 1 check valve 7 prevents the medium-pressure steam from flowing back into the steam-driven feedwater pump exhaust pipeline 2.

[0020] The medium-pressure driving steam pipeline 8 is connected to the pressure matching device 10. The pressure matching device 10 is connected to the medium-pressure heating steam pipeline in the plant through the medium-pressure driving steam pipeline 8.

[0021] The No. 2 electric valve 9 is installed on the medium-pressure driving steam pipeline 8. The No. 2 electric valve 9 is started and stopped in an interlocking manner or manually controlled according to the set values ​​of the temperature and pressure measuring points on the exhaust pipe 2 of the steam-driven feed water pump.

[0022] One end of the pressure matching device exhaust pipe 11 is connected to the pressure matching device 10 , and the other end is connected to the high-pressure deaerator 13 .

[0023] A safety valve 12 is installed on the exhaust pipe 11 of the pressure matcher to prevent overpressure of the steam after matching.

[0024] A No. 2 check valve 15 is installed on the pressure matching device exhaust pipe 11 to prevent the high-parameter steam in the deaerator from backflowing into the pressure matching device 10.

[0025] The No. 3 electric valve 14 is installed on the pressure matcher exhaust pipe 11.

[0026] A method for maintaining the operation of a steam-driven water supply pump under low load conditions comprises the following steps:

[0027] Under normal operating conditions, electric valve No. 1 6, electric valve No. 2 9 and electric valve No. 3 14 are closed, and the exhaust steam of the steam-driven feedwater pump 1 enters the low-pressure deaerator through the steam-driven feedwater pump exhaust pipe 2 and is only used to heat the low-pressure deaerator; the heating steam of the high-pressure deaerator 13 is provided by the heating steam in the plant, and the pressure matcher 10 is not operating at this time.

[0028] When the heat load is low to a certain extent, due to the low steam consumption of the low-pressure deaerator heating steam, when the exhaust pressure of the steam-driven feedwater pump 1 increases to a certain set value, open the No. 1 electric valve 6, No. 2 electric valve 9 and No. 3 electric valve 14, open the medium-pressure heating steam in the plant, and the steam enters the pressure matcher 10 through the medium-pressure driving steam pipeline 8. The pressure matcher 10 draws the low-pressure steam discharged by the steam-driven feedwater pump 1. The matched steam enters the high-pressure deaerator 13 through the pressure matcher exhaust pipeline 11, which is used to heat the high-pressure deaerator, thereby increasing the steam consumption of the steam-driven feedwater pump 1, thereby solving the problem that the steam-driven feedwater pump cannot operate under low-load conditions. The above set values ​​are set according to the parameters provided by the steam-driven feedwater pump manufacturer.

[0029] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the present invention. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A structure for maintaining the operation of a steam-driven feedwater pump under low-load conditions, comprising a steam-driven feedwater pump, a high-pressure deaerator and a steam-driven feedwater pump exhaust pipe; the steam-driven feedwater pump exhaust pipe is connected to the steam-driven feedwater pump; characterized in that: It also includes a low-pressure steam pipeline, No. 1 electric valve, No. 1 check valve, medium-pressure drive steam pipeline, No. 2 electric valve, pressure matcher, pressure matcher exhaust pipeline, safety valve, No. 3 electric valve, No. 2 check valve and high-pressure deaerator; one end of the low-pressure steam pipeline is connected to the exhaust pipeline of the steam-driven feed water pump, and the other end is connected to the pressure matcher; No. 1 electric valve and No. 1 check valve are installed on the low-pressure steam pipeline; the medium-pressure drive steam pipeline is connected to the pressure matcher; No. 2 electric valve is installed on the medium-pressure drive steam pipeline; one end of the pressure matcher exhaust pipeline is connected to the pressure matcher, and the other end is connected to the high-pressure deaerator; the safety valve, No. 3 electric valve and No. 2 check valve are all installed on the pressure matcher exhaust pipeline; a pressure measuring point is provided on the steam-driven feed water pump exhaust pipeline.

2. The structure for maintaining the operation of a steam-driven water supply pump under low-load conditions according to claim 1 is characterized in that: The No. 1 electric valve and the No. 2 electric valve are both electric gate valves.

3. The structure for maintaining the operation of a steam-driven water supply pump under low-load conditions according to claim 1 is characterized in that: The No. 3 electric valve is an electric stop valve.

4. A method for maintaining the operation of a steam-driven water supply pump under low load conditions, characterized in that: The method is carried out by using the structure for maintaining the operation of the steam-driven water supply pump under low-load conditions as described in any one of claims 1 to 3, comprising the following steps: Under normal working conditions, the No. 1 electric valve, No. 2 electric valve and No. 3 electric valve are closed, and the exhaust steam of the steam-driven feedwater pump enters the low-pressure deaerator through the steam-driven feedwater pump exhaust pipe and is only used to heat the low-pressure deaerator; the heating steam for the high-pressure deaerator is provided by the heating steam in the plant, and the pressure matching device does not operate at this time; When the heat load is low to a certain extent, the steam consumption of the low-pressure deaerator for heating steam is too low. When the exhaust pressure of the steam-driven feedwater pump rises to a certain set value, the No. 1 electric valve, No. 2 electric valve and No. 3 electric valve are opened to open the medium-pressure heating steam in the plant. The steam enters the pressure matcher through the medium-pressure driven steam pipeline. The pressure matcher draws the low-pressure steam discharged by the steam-driven feedwater pump. The matched steam enters the high-pressure deaerator through the pressure matcher exhaust pipeline and is used to heat the high-pressure deaerator, thereby increasing the steam consumption of the steam-driven feedwater pump.

5. The method for maintaining the operation of a steam-driven water supply pump under low-load conditions according to claim 4, characterized in that: The set value is set according to the parameters provided by the steam-driven water supply pump manufacturer.

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