Complementary steam flow calculation method for full-cycle steam admission type steam turbine

Abstract

The invention provides a steam supplementing flow calculation method for a full-cycle steam admission type steam turbine. The method comprises the steps that the corrected first-stage pressure of a high-pressure cylinder of the steam turbine is obtained; the corrected steam supplementing valve rear pressure of the steam turbine is obtained; according to the first-stage pressure of the high-pressure cylinder and the rear pressure of the steam supplementing valve, the steam inlet flow of the high-pressure adjusting valve when the steam supplementing valve is opened by different opening degrees is obtained; and according to the main steam flow and the steam inlet flow of the high-pressure adjusting valve, the steam inlet flow of the steam supplementing valve when different opening degrees are opened is obtained. According to the steam supplementing flow calculation method of the full-cycle steam admission type turbine, the steam supplementing flow of the steam supplementing valve can be simply, efficiently and accurately calculated, and technical support is provided for unit frequency modulation capacity and economical efficiency analysis.

Description

Technical Field

[0001] The present invention belongs to the technical field of steam turbine units for thermal power generation, and specifically relates to a method for calculating make-up steam flow rate of a full-arc admission steam turbine, a terminal device, and a computer-readable storage medium. Background Art

[0002] Currently, most ultra-supercritical steam turbines adopt a throttle governing method without a governing stage, that is, a full-arc admission + make-up steam valve regulation method. There is no governing stage. The first-stage inclined stationary blades of the high-pressure and intermediate-pressure cylinders are tangentially admitted. The first-stage moving blades are no different from general pressure stages. Fully opening the valves (excluding the make-up steam valve) is beneficial to improving the efficiency of the steam turbine. However, when the make-up steam valve is opened under summer operating conditions, the efficiency will decrease, and the frequency regulation task has to be borne by the make-up steam valve.

[0003] The first stage of the high pressure uses inclined stationary blades. The design of the first-stage moving blades is no different from that of general pressure stages. When the flow rate changes during constant-pressure operation, the temperature changes of each stage are small, and there are no special strength and vibration problems, which is also more beneficial to improving the efficiency of the steam turbine. However, in order to ensure the economy under rated conditions, bypass regulation is generally designed as a supplement to the throttle governing method. A bypass regulating valve is set after a certain pressure stage of the steam turbine to supply steam to the subsequent pressure stages, so as to increase the total steam inlet volume of the steam turbine to increase the output of the unit. The steam passing through the bypass valve is throttled steam, which itself has a certain loss. Then, it is mixed with the steam that has done work after passing through the steam turbine inlet and the make-up steam point, disturbing the steam flow of the unit and increasing another part of the loss. To meet the requirements of power grid frequency regulation, throttling control must also be carried out during operation (the opening degree of the high-pressure control valve during operation is 37-55%), all of which will reduce the efficiency of the unit.

[0004] Therefore, in order to meet the requirements of power grid frequency regulation and minimize the impact of flow disturbance on economy, it is particularly important to calculate the make-up steam flow rate of a full-arc admission unit. The existing calculation methods for the make-up steam flow rate of full-arc admission units mainly rely on experience to determine the opening degree and flow rate of the make-up steam valve, which will lead to problems such as too small make-up steam flow rate during the operation of the unit, untimely response of the power grid frequency regulation, or too large make-up steam flow rate and poor economy. Summary of the Invention

[0005] In order to solve the above technical problems existing in the prior art, according to an embodiment of the present invention, a method for calculating make-up steam flow rate of a full-arc admission steam turbine, a terminal device, and a computer-readable storage medium are provided.

[0006] The method for calculating the supplementary steam flow rate of a full - circumference steam - admission steam turbine provided by one aspect of the embodiments of the present invention includes: obtaining the corrected first - stage pressure of the high - pressure cylinder of the steam turbine; obtaining the corrected pressure after the supplementary steam valve of the steam turbine; obtaining the steam inlet flow rate of the high - pressure regulating valve when the supplementary steam valve is opened at different openings according to the first - stage pressure of the high - pressure cylinder and the pressure after the supplementary steam valve; and obtaining the steam inlet flow rate of the supplementary steam valve when it is opened at different openings according to the main steam flow rate and the steam inlet flow rate of the high - pressure regulating valve.

[0007] In an example of the supplementary steam flow rate calculation method provided by the above - mentioned one aspect, the corrected first - stage pressure of the high - pressure cylinder of the steam turbine is calculated by using the following formula.

[0008]

[0009] Wherein, P1 represents the first - stage pressure of the high - pressure cylinder, P0 represents the designed value of the main steam pressure, P1 * represents the test value of the pressure before the first - stage of the high - pressure cylinder, and P0 * represents the designed value of the main steam pressure.

[0010] In an example of the supplementary steam flow rate calculation method provided by the above - mentioned one aspect, the corrected pressure after the supplementary steam valve of the steam turbine is calculated by using the following formula.

[0011]

[0012] Wherein, P2 represents the pressure after the supplementary steam valve, P0 represents the designed value of the main steam pressure, P2 * represents the test value of the pressure after the supplementary steam valve, and P0 * represents the designed value of the main steam pressure.

[0013] In an example of the supplementary steam flow rate calculation method provided by the above - mentioned one aspect, according to the first - stage pressure of the high - pressure cylinder and the pressure after the supplementary steam valve, and by using the following formula, the steam inlet flow rate of the high - pressure regulating valve when the supplementary steam valve is opened at different openings is calculated.

[0014]

[0015] Wherein, P1 represents the first - stage pressure of the high - pressure cylinder, P2 represents the pressure after the supplementary steam valve, G0 represents the steam inlet flow rate of the high - pressure regulating valve when the opening of the supplementary steam valve is 0, G1 represents the steam inlet flow rate of the high - pressure regulating valve when the supplementary steam valve is opened at a certain opening, P 01 represents the pressure before the first - stage of the high - pressure cylinder when the opening of the supplementary steam valve is 0, and P 02 represents the pressure after the supplementary steam valve when the opening of the supplementary steam valve is 0.

[0016] In an example of the supplementary steam flow rate calculation method provided by the above - mentioned one aspect, according to the main steam flow rate and the steam inlet flow rate of the high - pressure regulating valve, and by using the following formula, the steam inlet flow rate of the supplementary steam valve when it is opened at different openings is calculated.

[0017] G2 = G - G1

[0018] Among them, G2 represents the steam inlet flow rate of the supplementary steam valve at different opening degrees, G1 represents the high-pressure regulating valve steam inlet flow rate of the supplementary steam valve at different opening degrees, and G represents the main steam flow rate.

[0019] According to another aspect of the embodiment of the present invention, the terminal device includes a processor and a memory connected to the processor. Among them, the memory stores program instructions; the processor is used to execute the program instructions stored in the memory to implement the supplementary steam flow calculation method as described above.

[0020] According to yet another aspect of the embodiment of the present invention, a computer-readable storage medium stores program instructions, and when the program instructions are executed, the supplementary steam flow calculation method as described above is implemented.

[0021] Beneficial effects: The supplementary steam flow calculation method of the full-arc admission steam turbine of the present invention can simply, efficiently, and accurately calculate the supplementary steam flow rate of the supplementary steam valve, providing technical support for the unit frequency modulation ability and economic analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Through the following description in conjunction with the drawings, the above and other aspects, features, and advantages of the embodiments of the present invention will become clearer. In the drawings:

[0023] Figure 1 is a schematic diagram of the parameters of the high-pressure cylinder of the steam turbine according to the embodiment of the present invention;

[0024] Figure 2 is a flowchart of the supplementary steam flow calculation method of the full-arc admission steam turbine according to the embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of the terminal device according to the embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the computer storage medium according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0028] Those skilled in the art of the present technology can understand that, unless specifically stated otherwise, the singular forms "a", "an", "the", and "said" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention means the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or their groups. It should be understood that when an element in this application is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may also be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any unit and all combinations of one or more of the associated listed items.

[0029] Those skilled in the art of the present technology can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention pertains. It should also be understood that terms such as those defined in a general dictionary should be understood as having a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as here.

[0030] Figure 1 is a schematic diagram of the parameters of the high-pressure cylinder of a steam turbine according to an embodiment of the present invention.

[0031] Referring to Figure 1 , P1 represents the corrected first-stage pressure of the high-pressure cylinder, P0 represents the designed value of the main steam pressure, and P2 represents the pressure after the supplementary steam valve.

[0032] Figure 2 is a flowchart of a method for calculating the supplementary steam flow rate of a full-arc admission steam turbine according to an embodiment of the present invention.

[0033] Referring to Figure 2 , in step S210, the corrected first-stage pressure of the steam turbine is obtained.

[0034] Specifically, the corrected first-stage pressure of the steam turbine is calculated using the following formula 1,

[0035]

[0036] where P1 represents the corrected first-stage pressure of the high-pressure cylinder, P0 represents the designed value of the main steam pressure, P1 * represents the test value of the pressure before the first stage of the high-pressure cylinder, and P0 * represents the designed value of the main steam pressure.

[0037] In step S220, obtain the corrected pressure after the steam admission valve of the steam turbine.

[0038] Specifically, use the following formula (2) to calculate the corrected pressure after the steam admission valve of the steam turbine.

[0039]

[0040] Wherein, P2 represents the corrected pressure after the steam admission valve, and P2 * represents the test value of the pressure after the steam admission valve, and P0 * represents the design value of the main steam pressure.

[0041] In step S230, obtain the steam inlet flow rate of the high-pressure regulating valve when the steam admission valve is opened at different openings according to the first-stage pressure of the high-pressure cylinder and the pressure after the steam admission valve. Among them, for a full-arc admission steam turbine, when the high-pressure regulating valve is kept fully open, the flow area remains unchanged. Then, regard the first stage to the steam admission stage of the high-pressure cylinder as a stage group, and the main steam temperature remains unchanged during the test.

[0042] Specifically, according to the first-stage pressure of the high-pressure cylinder and the pressure after the steam admission valve, and use the following formula (3) to calculate the steam inlet flow rate of the high-pressure regulating valve when the steam admission valve is opened at different openings.

[0043]

[0044] Wherein, G0 represents the steam inlet flow rate of the high-pressure regulating valve when the opening of the steam admission valve is 0, G1 represents the steam inlet flow rate of the high-pressure regulating valve when the steam admission valve is opened at a certain opening, and P 01 represents the pressure before the first stage of the high-pressure cylinder when the opening of the steam admission valve is 0, and P 02 represents the pressure after the steam admission valve when the opening of the steam admission valve is 0.

[0045] In step S240, obtain the steam inlet flow rate of the steam admission valve when it is opened at different openings according to the main steam flow rate and the steam inlet flow rate of the high-pressure regulating valve.

[0046] Specifically, according to the main steam flow rate and the steam inlet flow rate of the high-pressure regulating valve, and use the following formula (4) to calculate the steam inlet flow rate of the steam admission valve when it is opened at different openings.

[0047] G2 = G - G1 (4)

[0048] Wherein, G2 represents the steam inlet flow rate of the steam admission valve when it is opened at different openings, G represents the main steam flow rate, which includes the steam inlet flow rate of the high-pressure regulating valve and the steam inlet flow rate of the steam admission valve when the steam admission valve is opened at different openings.

[0049] Next, use Figure 2The supplementary steam flow calculation method shown is used to calculate different supplementary steam valve opening conditions under a 1000 MW load for a certain DKY4-4N45AU type, ultra-supercritical, once-through reheat, single-shaft, four-cylinder four-exhaust, reaction type steam turbine. Table 1 below shows the main data of the steam inlet flow of the steam turbine at different supplementary steam valve openings.

[0050] Table 1

[0051]

[0052] Among them, taking the 50% opening condition as an example,

[0053] The corrected pressure of the first stage of the high-pressure cylinder:

[0054] The corrected pressure after the supplementary steam valve:

[0055] Among them, when the opening of the supplementary steam valve is 50%, the steam inlet flow of the high-pressure regulating valve:

[0056]

[0057] When the opening of the supplementary steam valve is 50%, the steam inlet flow of the supplementary steam valve:

[0058] G2 = G - G1 = 2991.62 - 2616.80 = 374.82.

[0059] In summary, according to the supplementary steam flow calculation method of the full-arc admission steam turbine of the embodiment of the present invention, the supplementary steam flow of the supplementary steam valve can be calculated simply, efficiently and accurately, providing technical support for the unit frequency modulation ability and economic analysis.

[0060] In addition, to implement the supplementary steam flow calculation method of the full-arc admission steam turbine in the above embodiment, the present application also provides a terminal device 300. For details, please refer to Figure 3 , the terminal device 300 of the embodiment of the present application includes a processor 31, a memory 32, an input / output device 33 and a bus 34.

[0061] The processor 31, the memory 32 and the input / output device 33 are respectively connected to the bus 34. The memory 32 stores program data, and the processor 31 is used to execute the program data to implement the supplementary steam flow calculation method of the full-arc admission steam turbine described in the above embodiment.

[0062] In an embodiment of the present application, the processor 31 may also be referred to as a CPU (Central Processing Unit). The processor 31 may be an integrated voltage control system chip with signal processing capabilities. The processor 31 may also be a general-purpose processor, a digital signal processor (DSP, Digital Signal Process), an application-specific integrated voltage control system (ASIC, Application Specific Integrated Circuit), a field-programmable gate array (FPGA, Field Programmable Gate Array), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor may be a microprocessor or the processor 31 may also be any conventional processor, etc.

[0063] The present application also provides a computer storage medium. Please continue to refer to Figure 4 , Figure 4 FIG. is a schematic structural diagram of an embodiment of the computer storage medium provided by the present application. Program data 41 is stored in the computer storage medium 40. When the program data 41 is executed by a processor, it is used to implement the make-up steam flow calculation method of the full-arc admission steam turbine in the above embodiment.

[0064] When the embodiment of the present application is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, RandomAccess Memory), magnetic disks, or optical discs that can store program codes.

[0065] The above are only the embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A method for calculating the supplementary steam flow rate of a full - circumferential steam inlet steam turbine, characterized in that, The supplementary steam flow calculation method includes: Obtaining the corrected first-stage pressure of the high-pressure cylinder of the steam turbine; Obtaining the corrected pressure after the supplementary steam valve of the steam turbine; Obtaining the admission flow rate of the high-pressure regulating valve when the supplementary steam valve is opened at different openings according to the first-stage pressure of the high-pressure cylinder and the pressure after the supplementary steam valve; Obtaining the admission flow rate of the supplementary steam valve when it is opened at different openings according to the main steam flow rate and the admission flow rate of the high-pressure regulating valve.

2. The supplementary steam flow calculation method according to claim 1, wherein Calculating the corrected first-stage pressure of the high-pressure cylinder of the steam turbine by using the following formula, Among them, P1 represents the pressure of the first stage of the high-pressure cylinder, P0 represents the designed value of the main steam pressure, P1 * represents the test value of the pressure before the first stage of the high-pressure cylinder, P0 * represents the designed value of the main steam pressure.

3. The supplementary steam flow calculation method according to claim 1, characterized in that Calculating the corrected pressure after the supplementary steam valve of the steam turbine by using the following formula, Among them, P2 represents the pressure after the extraction steam valve, P0 represents the designed value of the main steam pressure, and P2 * represents the test value of the pressure after the extraction steam valve, and P0 * represents the designed value of the main steam pressure.

4. The supplementary steam flow calculation method according to claim 1, wherein Calculating the admission flow rate of the high-pressure regulating valve when the supplementary steam valve is opened at different openings according to the first-stage pressure of the high-pressure cylinder and the pressure after the supplementary steam valve, and using the following formula, Among them, P1 represents the pressure of the first stage of the high-pressure cylinder, P2 represents the pressure after the steam admission valve, G0 represents the steam inlet flow rate of the high-pressure regulating valve when the steam admission valve opening is 0, G1 represents the steam inlet flow rate of the high-pressure regulating valve when the steam admission valve is opened to a certain opening, P 01 represents the pressure before the first stage of the high-pressure cylinder when the steam admission valve opening is 0, P 02 represents the pressure after the steam admission valve when the steam admission valve opening is 0.

5. The supplementary steam flow calculation method according to claim 1, characterized in that, Calculating the admission flow rate of the supplementary steam valve when it is opened at different openings according to the main steam flow rate and the admission flow rate of the high-pressure regulating valve, and using the following formula, G2 = G - G1 Wherein, G2 represents the admission flow rate of the supplementary steam valve when it is opened at different openings, G1 represents the admission flow rate of the high-pressure regulating valve when the supplementary steam valve is opened at different openings, and G represents the main steam flow rate.

6. A terminal device, characterized in that, The terminal device includes a processor and a memory connected to the processor, wherein, The memory stores program instructions; The processor is configured to execute the program instructions stored in the memory to implement the supplementary steam flow calculation method according to any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program instructions, wherein the program instructions, when executed, implement the supplementary steam flow calculation method according to any one of claims 1 to 5.

Images