Method and device for controlling exhaust steam pressure of intermediate-pressure cylinder, controller and storage medium

Abstract

The invention provides an intermediate pressure cylinder exhaust steam pressure control method and device, a controller and a storage medium. The method comprises the steps of determining a current intermediate-pressure cylinder exhaust steam pressure standard value, a current intermediate-pressure cylinder exhaust steam pressure upper limit and a current intermediate-pressure cylinder exhaust steam pressure lower limit based on the current main steam flow of a steam turbine; if the actual value of the exhaust steam pressure of the intermediate-pressure cylinder is between the lower limit of the exhaust steam pressure of the current intermediate-pressure cylinder and the upper limit of the exhaust steam pressure of the current intermediate-pressure cylinder, updating the set value of the exhaust steam pressure of the intermediate-pressure cylinder of an exhaust steam pressure regulator to the standard value of the exhaust steam pressure of the current intermediate-pressure cylinder; the opening degree of a communicating pipe butterfly valve is adjusted based on the updated medium-pressure cylinder exhaust steam pressure regulator; otherwise, the communicating pipe butterfly valve is controlled to be turned down or turned up according to the preset speed. According to the method, the intermediate-pressure cylinder exhaust steam pressure set value of the intermediate-pressure cylinder exhaust steam pressure regulator can be automatically updated, the situation that the intermediate-pressure cylinder exhaust steam pressure actual value deviates from the intermediate-pressure cylinder exhaust steam pressure set value too much is avoided, and safe and economical operation of a steam turbine unit is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of steam turbine control, and in particular to a method, device, controller and storage medium for controlling the exhaust pressure of an intermediate pressure cylinder. Background Art

[0002] like Figure 1 As shown, the exhaust pressure of the intermediate pressure cylinder of the steam turbine of the thermal power generating unit for extraction condensation heating is currently controlled by controlling the opening of the connecting pipe butterfly valve, and the opening of the connecting pipe butterfly valve is controlled by an intermediate pressure cylinder exhaust pressure regulator such as a proportional-integral-derivative controller (PID controller). The set value of the exhaust pressure of the intermediate pressure cylinder of the PID controller is given by the operator. In the automatic control mode, the PID controller accepts the exhaust pressure command of the intermediate pressure cylinder of the steam turbine given by the operator (i.e., the set value of the exhaust pressure of the intermediate pressure cylinder), and automatically adjusts the exhaust pressure of the intermediate pressure cylinder of the steam turbine to be consistent with the set value of the exhaust pressure of the intermediate pressure cylinder.

[0003] However, the inventors found in the process of implementing the present invention that: on the one hand, the set value of the exhaust steam pressure of the intermediate pressure cylinder given by the operating personnel needs to be manually set by the operating personnel according to experience based on the load of the unit, which not only requires the operating personnel to make frequent adjustments, but also may introduce misoperation. On the other hand, the set value of the exhaust steam pressure of the intermediate pressure cylinder given by the operating personnel according to experience may deviate too much from the actual value of the exhaust steam pressure of the intermediate pressure cylinder, which may cause the exhaust steam pressure regulator of the intermediate pressure cylinder to be cut off due to divergence or excessive deviation during the automatic adjustment process, thereby affecting the safe and economical operation of the unit. Moreover, since the steam source of the small steam turbine used by the steam-driven water supply pump of the unit is taken from the exhaust steam of the intermediate pressure cylinder of the steam turbine, if the deviation is too large, it will also affect the operation of the small steam turbine, and at the same time, it will also affect the enthalpy drop of the intermediate pressure cylinder, causing the last stage blades of the intermediate pressure cylinder to be overloaded or the exhaust steam temperature of the intermediate pressure cylinder to be too high. Summary of the invention

[0004] The embodiments of the present invention provide a method, device, controller and storage medium for controlling the exhaust steam pressure of an intermediate pressure cylinder to solve the problem that the current method for controlling the exhaust steam pressure of an intermediate pressure cylinder may affect the safe and economical operation of the unit.

[0005] In a first aspect, an embodiment of the present invention provides a method for controlling exhaust steam pressure of an intermediate pressure cylinder, comprising:

[0006] Based on the current main steam flow of the steam turbine, determine the current intermediate pressure cylinder exhaust pressure standard value, the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit of the steam turbine;

[0007] Obtaining an actual value of the intermediate pressure cylinder exhaust pressure of the steam turbine, and comparing the actual value of the intermediate pressure cylinder exhaust pressure with a current intermediate pressure cylinder exhaust pressure upper limit and a current intermediate pressure cylinder exhaust pressure lower limit respectively;

[0008] If the actual value of the intermediate pressure cylinder exhaust pressure is greater than the current intermediate pressure cylinder exhaust pressure lower limit and less than the current intermediate pressure cylinder exhaust pressure upper limit, the intermediate pressure cylinder exhaust pressure setting value of the intermediate pressure cylinder exhaust pressure regulator of the steam turbine is updated to the current intermediate pressure cylinder exhaust pressure standard value, and the opening of the connecting pipe butterfly valve between the intermediate pressure cylinder and the low pressure cylinder of the steam turbine is adjusted based on the updated intermediate pressure cylinder exhaust pressure regulator;

[0009] If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to close or open according to a preset rate.

[0010] In a possible implementation, the determining of the current standard value of the intermediate pressure cylinder exhaust pressure, the current upper limit of the intermediate pressure cylinder exhaust pressure, and the current lower limit of the intermediate pressure cylinder exhaust pressure of the steam turbine based on the current main steam flow of the steam turbine includes:

[0011] Based on the correspondence between the main steam flow rate and the standard value of the intermediate pressure cylinder exhaust pressure, determine the standard value of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow rate of the steam turbine, and record it as the current standard value of the intermediate pressure cylinder exhaust pressure;

[0012] Based on the corresponding relationship between the main steam flow rate and the upper limit of the intermediate pressure cylinder exhaust pressure, the upper limit of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow rate of the steam turbine is determined, and recorded as the current upper limit of the intermediate pressure cylinder exhaust pressure;

[0013] Based on the corresponding relationship between the main steam flow and the lower limit of the intermediate pressure cylinder exhaust pressure, the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow of the steam turbine is determined and recorded as the current lower limit of the intermediate pressure cylinder exhaust pressure.

[0014] In a possible implementation, the process of determining the correspondence between the main steam flow rate and the standard value of the intermediate pressure cylinder exhaust pressure includes:

[0015] For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is adjusted downward from the intermediate pressure cylinder exhaust pressure base value until the steam inlet regulating valve opening of the small steam turbine reaches the safety opening threshold, and the intermediate pressure cylinder exhaust pressure value at this time is recorded as the intermediate pressure cylinder exhaust pressure standard value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure base value is the intermediate pressure cylinder exhaust pressure value corresponding to the steam turbine under pure condensing conditions;

[0016] Each main steam flow value and the standard value of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the standard value of the intermediate pressure cylinder exhaust pressure.

[0017] In a possible implementation, the process of determining the corresponding relationship between the main steam flow rate and the upper limit of the intermediate pressure cylinder exhaust pressure includes:

[0018] For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is adjusted upward from the intermediate pressure cylinder exhaust pressure base value until the intermediate pressure cylinder exhaust temperature reaches the exhaust temperature safety threshold, and the intermediate pressure cylinder exhaust pressure value at this time is recorded as the intermediate pressure cylinder exhaust pressure upper limit value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure base value is the intermediate pressure cylinder exhaust pressure value corresponding to the steam turbine under pure condensing conditions;

[0019] Each main steam flow value and the upper limit value of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the upper limit of the intermediate pressure cylinder exhaust pressure.

[0020] In a possible implementation, the process of determining the corresponding relationship between the main steam flow rate and the lower limit of the intermediate pressure cylinder exhaust pressure includes:

[0021] For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is adjusted downward from the intermediate pressure cylinder exhaust pressure base value until the opening of the steam inlet regulating valve of the small steam turbine reaches the maximum opening threshold, and the intermediate pressure cylinder exhaust pressure value at this time is recorded as the intermediate pressure cylinder exhaust pressure lower limit value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure base value is the intermediate pressure cylinder exhaust pressure value corresponding to the steam turbine under pure condensing conditions;

[0022] Each main steam flow value and the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the lower limit of the intermediate pressure cylinder exhaust pressure.

[0023] In a possible implementation manner, the preset rate includes a first preset rate and a second preset rate;

[0024] If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current intermediate pressure cylinder exhaust pressure lower limit, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current intermediate pressure cylinder exhaust pressure upper limit, the connecting pipe butterfly valve is controlled to close or open at a preset rate, including:

[0025] If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to close at the first preset rate;

[0026] If the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to open wider according to the second preset rate.

[0027] In a possible implementation manner, the process of determining the first preset rate is:

[0028] If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, the difference between the actual value of the intermediate pressure cylinder exhaust pressure and the current lower limit of the intermediate pressure cylinder exhaust pressure is calculated and recorded as the first difference, and the first preset rate is determined according to the first difference;

[0029] The process of determining the second preset rate is as follows:

[0030] If the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, the difference between the actual value of the intermediate pressure cylinder exhaust pressure and the current upper limit of the intermediate pressure cylinder exhaust pressure is calculated and recorded as the second difference, and the second preset rate is determined based on the second difference.

[0031] In a second aspect, an embodiment of the present invention provides a medium pressure cylinder exhaust steam pressure control device, comprising:

[0032] The first processing module is used to determine the current intermediate pressure cylinder exhaust pressure standard value, the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit of the steam turbine based on the current main steam flow of the steam turbine;

[0033] The second processing module is used to obtain the actual value of the intermediate pressure cylinder exhaust pressure of the steam turbine, and compare the actual value of the intermediate pressure cylinder exhaust pressure with the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit respectively;

[0034] The first control module is used to update the set value of the intermediate pressure cylinder exhaust pressure of the steam turbine to the current standard value of the intermediate pressure cylinder exhaust pressure if the actual value of the intermediate pressure cylinder exhaust pressure is greater than the current lower limit of the intermediate pressure cylinder exhaust pressure and less than the current upper limit of the intermediate pressure cylinder exhaust pressure, and adjust the opening of the butterfly valve of the connecting pipe between the intermediate pressure cylinder and the low pressure cylinder of the steam turbine based on the updated intermediate pressure cylinder exhaust pressure regulator;

[0035] The second control module is used to control the connecting pipe butterfly valve to close or open at a preset rate if the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure.

[0036] In a third aspect, an embodiment of the present invention provides a controller comprising a memory and a processor, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to perform the steps of the method described in the first aspect or any possible implementation of the first aspect.

[0037] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in the first aspect or any possible implementation of the first aspect are implemented.

[0038] The embodiment of the present invention provides a method, device, controller and storage medium for controlling the exhaust pressure of an intermediate pressure cylinder. The method determines the standard value of the exhaust pressure of the intermediate pressure cylinder of the steam turbine, the upper limit of the exhaust pressure of the intermediate pressure cylinder and the lower limit of the exhaust pressure of the intermediate pressure cylinder of the steam turbine based on the current main steam flow of the steam turbine, obtains the actual value of the exhaust pressure of the intermediate pressure cylinder of the steam turbine, and then compares the actual value of the exhaust pressure of the intermediate pressure cylinder with the upper limit of the exhaust pressure of the intermediate pressure cylinder and the lower limit of the exhaust pressure of the intermediate pressure cylinder respectively. When the actual value of the exhaust pressure of the intermediate pressure cylinder is greater than the current exhaust pressure of the intermediate pressure cylinder, the exhaust pressure of the intermediate pressure cylinder can be controlled. When the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to close or open at a preset rate. It can not only automatically update the set value of the intermediate pressure cylinder exhaust pressure of the intermediate pressure cylinder exhaust pressure regulator during the heating period, reduce the workload of the operating personnel and reduce erroneous operations, but also control the connecting pipe butterfly valve to close or open at a preset rate to forcibly open and close the connecting pipe butterfly valve when the actual value of the intermediate pressure cylinder exhaust pressure deviates from the set value of the intermediate pressure cylinder exhaust pressure by a large amount, so as to prevent problems such as insufficient steam source pressure of the small steam turbine, overload of the last stage blades of the intermediate pressure cylinder, and excessively high exhaust temperature of the intermediate pressure cylinder caused by the excessive deviation of the actual value of the intermediate pressure cylinder exhaust pressure from the set value of the intermediate pressure cylinder exhaust pressure, thereby ensuring safe and economical operation of the steam turbine unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 is a structural schematic diagram of a steam turbine system provided by an embodiment of the present invention;

[0041] Figure 2 is a flow chart of an implementation method of a medium pressure cylinder exhaust steam pressure control method provided by an embodiment of the present invention;

[0042] Figure 3 is a schematic diagram of a relationship curve between the regulating stage pressure and the exhaust pressure of the intermediate pressure cylinder provided in an embodiment of the present invention;

[0043] Figure 4 is a flow chart of an implementation method of a medium pressure cylinder exhaust pressure control method provided by another embodiment of the present invention;

[0044] Figure 5 It is a structural schematic diagram of a medium pressure cylinder exhaust pressure control device provided by an embodiment of the present invention;

[0045] Figure 6 is a schematic diagram of a controller provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0047] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0048] See also Figure 2 , which shows a flow chart of the implementation of the medium pressure cylinder exhaust steam pressure control method provided by an embodiment of the present invention, and is described in detail as follows:

[0049] In step 201, based on the current main steam flow of the steam turbine, the current intermediate pressure cylinder exhaust pressure standard value, the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit of the steam turbine are determined.

[0050] In this embodiment, in order to set the set value of the intermediate pressure cylinder exhaust pressure more accurately, considering that the main steam flow of the steam turbine changes when the unit load changes, the intermediate pressure cylinder exhaust pressure should also follow the change of the main steam flow of the steam turbine, and different main steam flows of the steam turbine should correspond to different intermediate pressure cylinder exhaust pressures. Therefore, the corresponding intermediate pressure cylinder exhaust pressure can be determined based on the current main steam flow of the steam turbine, that is, the current intermediate pressure cylinder exhaust pressure standard value, so that the intermediate pressure cylinder exhaust pressure can automatically track the change of the current main steam flow of the steam turbine.

[0051] In addition, in order to prevent the actual value of the intermediate pressure cylinder exhaust pressure from deviating too much from the set value of the intermediate pressure cylinder exhaust pressure, or the intermediate pressure cylinder exhaust pressure regulator from being cut off during the automatic adjustment process due to the divergence of the adjustment characteristics, which ultimately affects the safe and economical operation of the unit, in addition to determining the corresponding current intermediate pressure cylinder exhaust pressure standard value based on the current main steam flow of the turbine, the corresponding intermediate pressure cylinder exhaust pressure upper limit and intermediate pressure cylinder exhaust pressure lower limit can also be determined, so that when the intermediate pressure cylinder exhaust pressure reaches the intermediate pressure cylinder exhaust pressure upper limit or the intermediate pressure cylinder exhaust pressure lower limit, a forced switching command can be issued to control the connecting pipe butterfly valve between the intermediate pressure cylinder and the low pressure cylinder, thereby avoiding the actual value of the intermediate pressure cylinder exhaust pressure from deviating too much from the set value of the intermediate pressure cylinder exhaust pressure.

[0052] Optionally, based on the current main steam flow of the steam turbine, determining the current standard value of the intermediate pressure cylinder exhaust pressure, the current upper limit of the intermediate pressure cylinder exhaust pressure, and the current lower limit of the intermediate pressure cylinder exhaust pressure of the steam turbine may include:

[0053] Based on the correspondence between the main steam flow and the standard value of the intermediate pressure cylinder exhaust pressure, the standard value of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow of the steam turbine is determined and recorded as the current standard value of the intermediate pressure cylinder exhaust pressure.

[0054] Based on the correspondence between the main steam flow and the upper limit of the intermediate pressure cylinder exhaust pressure, the upper limit of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow of the steam turbine is determined and recorded as the current upper limit of the intermediate pressure cylinder exhaust pressure.

[0055] Based on the corresponding relationship between the main steam flow and the lower limit of the intermediate pressure cylinder exhaust pressure, the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow of the steam turbine is determined and recorded as the current lower limit of the intermediate pressure cylinder exhaust pressure.

[0056] In this embodiment, considering that there is a corresponding relationship between the exhaust pressure of the intermediate pressure cylinder of the steam turbine and the main steam flow, for example, the function generator provided by the distributed control system (DCS) can be used to obtain a relationship curve between "steam turbine steam inlet (i.e., main steam flow)" and "standard value of intermediate pressure cylinder exhaust pressure", and then automatically generate the set value of the intermediate pressure cylinder exhaust pressure required by the PID regulator of the connecting pipe butterfly valve according to the steam inlet of the steam turbine, so that the exhaust pressure of the intermediate pressure cylinder can automatically track the changes in the current main steam flow of the steam turbine.

[0057] On this basis, the high and low ranges of the relationship curve between "steam turbine inlet volume" and "standard value of intermediate pressure cylinder exhaust pressure" are determined, so as to automatically generate the "intermediate pressure cylinder exhaust pressure upper limit curve (i.e., the upper limit of intermediate pressure cylinder exhaust pressure)" and "intermediate pressure cylinder exhaust pressure lower limit curve (i.e., the lower limit of intermediate pressure cylinder exhaust pressure)" according to the main steam flow of the steam turbine. When the actual value of the intermediate pressure cylinder exhaust pressure reaches the upper or lower limit, a forced switch command of the connecting pipe butterfly valve is issued. At this time, the connecting pipe butterfly valve no longer accepts the PID regulator opening command, but opens or closes at a preset rate until the intermediate pressure cylinder exhaust pressure returns to between the upper and lower limits. At the same time, the PID regulator valve opening command tracks the actual opening. After the interlocking forced switch command of the connecting pipe butterfly valve disappears, the opening command management authority is returned to the PID regulator, and the forced switch command is automatically switched back to the PID regulation command without disturbance.

[0058] Optionally, the process of determining the corresponding relationship between the main steam flow rate and the standard value of the intermediate pressure cylinder exhaust pressure may include:

[0059] For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is lowered from the intermediate pressure cylinder exhaust pressure basic value until the opening of the steam inlet regulating valve of the small turbine reaches the safe opening threshold. The intermediate pressure cylinder exhaust pressure value at this time is recorded as the intermediate pressure cylinder exhaust pressure standard value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure basic value is the intermediate pressure cylinder exhaust pressure value corresponding to the turbine under pure condensing conditions.

[0060] Each main steam flow value and the standard value of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the standard value of the intermediate pressure cylinder exhaust pressure.

[0061] Exemplarily, the regulating stage pressure of the steam turbine can be used to represent the main steam flow value, and then under heating conditions, the intermediate pressure cylinder exhaust pressure corresponding to each regulating stage pressure under pure condensing conditions is used as the basic value of the intermediate pressure cylinder exhaust pressure, and the intermediate pressure cylinder exhaust pressure is continued to be lowered until the opening of the steam inlet regulating valve of the small steam turbine reaches the safe opening threshold. For example, when the opening of the steam inlet regulating valve of the small steam turbine is opened to 50%, the intermediate pressure cylinder exhaust pressure value at this time is used as the standard value of the intermediate pressure cylinder exhaust pressure, and then each regulating stage pressure and the standard value of the intermediate pressure cylinder exhaust pressure corresponding to each regulating stage pressure are fitted to obtain the corresponding relationship between the main steam flow and the standard value of the intermediate pressure cylinder exhaust pressure.

[0062] For example: when the regulating stage pressure of the unit is 8.9MPa, the corresponding steam inlet volume or main steam flow of the steam turbine is 726t / h. At this time, the corresponding intermediate pressure cylinder exhaust pressure value under pure condensing conditions is 0.59MPa. Under heating conditions, the steam inlet regulating valve opening of the small steam turbine is 40%, and the safety opening threshold of the steam inlet regulating valve opening of the small steam turbine is 50%. Therefore, the intermediate pressure cylinder exhaust pressure value can be further lowered on the basis of 0.59Mpa until the steam inlet regulating valve opening of the small steam turbine is increased to 50%. At this time, the intermediate pressure cylinder exhaust pressure value is 0.52MPa, and 0.52MPa is used as the standard value of the intermediate pressure cylinder exhaust pressure corresponding to the steam inlet volume of 726t / h of the steam turbine. By analogy, the standard value of the intermediate pressure cylinder exhaust pressure corresponding to each regulating stage pressure is obtained, which is fitted into the relationship curve between "steam inlet volume of steam turbine" and "standard value of intermediate pressure cylinder exhaust pressure", such as Figure 3 As shown in A.

[0063] It should be noted that the specific safety opening threshold can be determined according to the safety margin actually required by the unit, and the specific value of the safety opening threshold is not limited in this embodiment. By adjusting the exhaust steam pressure of the intermediate pressure cylinder to the opening of the steam inlet regulating valve of the small steam turbine to reach the safety opening threshold, the determined standard value of the exhaust steam pressure of the intermediate pressure cylinder can ensure the safe operation of the small steam turbine while taking into account the economic efficiency of heating.

[0064] Optionally, the process of determining the corresponding relationship between the main steam flow rate and the upper limit of the intermediate pressure cylinder exhaust pressure may include:

[0065] For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is adjusted upward from the intermediate pressure cylinder exhaust pressure basic value until the intermediate pressure cylinder exhaust temperature reaches the exhaust temperature safety threshold. The intermediate pressure cylinder exhaust pressure value at this time is recorded as the intermediate pressure cylinder exhaust pressure upper limit value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure basic value is the intermediate pressure cylinder exhaust pressure value corresponding to the turbine under pure condensing conditions.

[0066] Each main steam flow value and the upper limit value of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the upper limit of the intermediate pressure cylinder exhaust pressure.

[0067] In this embodiment, the main steam flow of the steam turbine can also be represented by the pressures of multiple regulating stages of the steam turbine. Then, under the heating condition, the exhaust pressure of the intermediate pressure cylinder corresponding to the pressure of each regulating stage under the pure condensing condition is used as the basic value of the exhaust pressure of the intermediate pressure cylinder. The exhaust pressure of the intermediate pressure cylinder is continuously increased until the exhaust temperature of the intermediate pressure cylinder reaches the exhaust temperature safety threshold. For example, the exhaust temperature of the intermediate pressure cylinder rises to 360°C. The exhaust pressure value of the intermediate pressure cylinder at this time is used as the upper limit value of the exhaust pressure of the intermediate pressure cylinder.

[0068] For example: when the regulating stage pressure of the unit is 8.9MPa, the corresponding turbine steam inlet or main steam flow is 726t / h. At this time, the corresponding intermediate pressure cylinder exhaust pressure value under pure condensing conditions is 0.59MPa, and the intermediate pressure cylinder exhaust temperature under heating conditions is 348℃, while the exhaust temperature safety threshold is 360℃. Therefore, the intermediate pressure cylinder exhaust pressure value can be adjusted on the basis of 0.59Mpa until the intermediate pressure cylinder exhaust temperature rises to 360℃. At this time, the intermediate pressure cylinder exhaust pressure is 0.7MPa, and 7MPa is used as the upper limit of the intermediate pressure cylinder exhaust pressure corresponding to the turbine steam inlet of 726t / h. By analogy, the upper limit of the intermediate pressure cylinder exhaust pressure corresponding to each regulating stage pressure is obtained, which is fitted into the "intermediate pressure cylinder exhaust pressure upper limit curve", that is, the corresponding relationship curve between the main steam flow and the upper limit of the intermediate pressure cylinder exhaust pressure, such as Figure 3 As shown in B.

[0069] It should be noted that the specific exhaust temperature safety threshold can be determined according to actual conditions, and this embodiment does not limit the specific value of the exhaust temperature safety threshold. For example, the exhaust temperature safety threshold can be determined based on the exhaust temperature limit value provided by the host manufacturer and the required safety margin.

[0070] Optionally, the process of determining the corresponding relationship between the main steam flow rate and the lower limit of the intermediate pressure cylinder exhaust pressure may include:

[0071] For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is adjusted downward from the intermediate pressure cylinder exhaust pressure basic value until the opening of the steam inlet regulating valve of the small turbine reaches the maximum opening threshold. The intermediate pressure cylinder exhaust pressure value at this time is recorded as the lower limit value of the intermediate pressure cylinder exhaust pressure corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure basic value is the intermediate pressure cylinder exhaust pressure value corresponding to the turbine under pure condensing conditions.

[0072] Each main steam flow value and the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the lower limit of the intermediate pressure cylinder exhaust pressure.

[0073] In this embodiment, the main steam flow of the steam turbine can also be represented by the pressures of multiple regulating stages of the steam turbine. Then, under the heating condition, the exhaust pressure of the intermediate pressure cylinder corresponding to the pressure of each regulating stage under the pure condensing condition is used as the basic value of the exhaust pressure of the intermediate pressure cylinder. The exhaust pressure of the intermediate pressure cylinder is continuously lowered until the opening of the steam inlet regulating valve of the small steam turbine reaches the maximum opening threshold. For example, when the opening of the steam inlet regulating valve of the small steam turbine is opened to 60%, the exhaust pressure value of the intermediate pressure cylinder at this time is used as the lower limit of the exhaust pressure of the intermediate pressure cylinder.

[0074] For example: when the regulating stage pressure of the unit is 8.9MPa, the corresponding steam turbine inlet or main steam flow is 726t / h. At this time, the corresponding intermediate pressure cylinder exhaust pressure value under pure condensing conditions is 0.59MPa. Under heating conditions, the opening of the steam inlet regulating valve of the small steam turbine is 40%, and the maximum opening threshold of the steam inlet regulating valve of the small steam turbine is 60%. Therefore, the intermediate pressure cylinder exhaust pressure value can be further lowered on the basis of 0.59Mpa until the opening of the steam inlet regulating valve of the small steam turbine is increased to 60%. At this time, the intermediate pressure cylinder exhaust pressure value is 0.48MPa, and 0.48MPa is used as the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to the steam turbine inlet of 726t / h. By analogy, the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to each regulating stage pressure is obtained, which is fitted into the "intermediate pressure cylinder exhaust pressure lower limit curve", that is, the corresponding relationship curve between the main steam flow and the lower limit of the intermediate pressure cylinder exhaust pressure, such as Figure 3 As shown in C.

[0075] It should be noted that the specific maximum opening threshold can be determined according to the actual limit operating conditions of the unit, and this embodiment does not limit the specific value of the maximum opening threshold. By adjusting the exhaust pressure of the intermediate pressure cylinder to the opening of the steam inlet regulating valve of the small steam turbine to reach the maximum opening threshold, the limit value of the exhaust pressure of the intermediate pressure cylinder can be determined, thereby preventing the exhaust pressure of the intermediate pressure cylinder from exceeding the limit value.

[0076] In step 202, the actual value of the intermediate pressure cylinder exhaust pressure of the steam turbine is obtained, and the actual value of the intermediate pressure cylinder exhaust pressure is compared with the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit respectively.

[0077] In step 203, if the actual value of the intermediate pressure cylinder exhaust pressure is greater than the current lower limit of the intermediate pressure cylinder exhaust pressure and less than the current upper limit of the intermediate pressure cylinder exhaust pressure, the intermediate pressure cylinder exhaust pressure set value of the intermediate pressure cylinder exhaust pressure regulator of the steam turbine is updated to the current intermediate pressure cylinder exhaust pressure standard value, and the opening of the connecting pipe butterfly valve between the intermediate pressure cylinder and the low pressure cylinder of the steam turbine is adjusted based on the updated intermediate pressure cylinder exhaust pressure regulator.

[0078] In step 204, if the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current intermediate pressure cylinder exhaust pressure lower limit, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current intermediate pressure cylinder exhaust pressure upper limit, the connecting pipe butterfly valve is controlled to close or open according to a preset rate.

[0079] For example, Figure 4 As shown, the medium pressure cylinder exhaust pressure control method provided in this embodiment can be divided into a connecting pipe butterfly valve regulator set value generation module, a medium pressure cylinder exhaust pressure high / low limit generation module, a medium pressure cylinder exhaust pressure high / low limit control module and a connecting pipe butterfly valve PID regulator instruction and high / low limit control instruction switching module when implemented. Among them:

[0080] The connecting pipe butterfly valve regulator set value generation module is used to generate the current intermediate pressure cylinder exhaust pressure standard value according to the current main steam flow of the turbine, and send it to the connecting pipe butterfly valve PID regulator as the intermediate pressure cylinder exhaust pressure set value.

[0081] The intermediate pressure cylinder exhaust steam pressure high / low limit generation module is used to generate the current intermediate pressure cylinder exhaust steam pressure upper limit and the current intermediate pressure cylinder exhaust steam pressure lower limit according to the current main steam flow of the turbine.

[0082] The medium pressure cylinder exhaust pressure high / low limit control module is used to send a forced switching command to the connecting pipe butterfly valve when the actual value of the medium pressure cylinder exhaust pressure reaches the current medium pressure cylinder exhaust pressure upper limit or the current medium pressure cylinder exhaust pressure lower limit, that is, to control the connecting pipe butterfly valve to close or open according to the preset rate.

[0083] The connecting pipe butterfly valve PID regulator instruction and high and low limit control instruction switching module is used to complete the switching of the connecting pipe butterfly valve opening instruction between the "PID regulator instruction" and the "forced switch instruction" when the intermediate pressure cylinder exhaust pressure reaches the current intermediate pressure cylinder exhaust pressure upper limit or the current intermediate pressure cylinder exhaust pressure lower limit, and after returning to between the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit.

[0084] The connecting pipe butterfly valve regulator set value generation module, the medium pressure cylinder exhaust pressure high / low limit generation module, the medium pressure cylinder exhaust pressure high / low limit control module and the connecting pipe butterfly valve PID regulator instruction and high and low limit control instruction switching module are as follows Figure 4 The signal flow direction is connected to realize the control of the opening of the connecting pipe butterfly valve, and then the exhaust pressure of the intermediate pressure cylinder is adjusted within a reasonable range to prevent problems such as insufficient steam source pressure of the small steam turbine, overload of the last stage blades of the intermediate pressure cylinder, and excessive temperature of the intermediate exhaust caused by the exhaust pressure of the intermediate pressure cylinder deviating too much from the design value, so as to ensure the safe and economical operation of the unit.

[0085] Optionally, the preset rate may include a first preset rate and a second preset rate.

[0086] If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current intermediate pressure cylinder exhaust pressure lower limit, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current intermediate pressure cylinder exhaust pressure upper limit, the connecting pipe butterfly valve is controlled to close or open according to the preset rate, which may include:

[0087] If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to close at a first preset rate.

[0088] If the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current intermediate pressure cylinder exhaust pressure upper limit, the connecting pipe butterfly valve is controlled to open wider according to the second preset rate.

[0089] Optionally, the process of determining the first preset rate may be:

[0090] If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, the difference between the actual value of the intermediate pressure cylinder exhaust pressure and the current lower limit of the intermediate pressure cylinder exhaust pressure is calculated, recorded as the first difference, and the first preset rate is determined based on the first difference.

[0091] The process of determining the second preset rate may be:

[0092] If the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, the difference between the actual value of the intermediate pressure cylinder exhaust pressure and the current upper limit of the intermediate pressure cylinder exhaust pressure is calculated and recorded as the second difference, and the second preset rate is determined based on the second difference.

[0093] In this embodiment, in order to adjust the intermediate pressure cylinder exhaust pressure back to the current intermediate pressure cylinder exhaust pressure lower limit and the current intermediate pressure cylinder exhaust pressure upper limit as soon as possible when the actual value of the intermediate pressure cylinder exhaust pressure reaches the current intermediate pressure cylinder exhaust pressure lower limit or the current intermediate pressure cylinder exhaust pressure upper limit, the corresponding first preset rate or second preset rate can be calculated according to the expected adjustment time and the first difference or the second difference. Alternatively, the values ​​of the first preset speed and the second preset rate can also be determined based on experience, which is not limited in this embodiment.

[0094] The embodiment of the present invention determines the current standard value of the intermediate pressure cylinder exhaust pressure of the steam turbine, the current upper limit of the intermediate pressure cylinder exhaust pressure and the current lower limit of the intermediate pressure cylinder exhaust pressure based on the current main steam flow of the steam turbine, and obtains the actual value of the intermediate pressure cylinder exhaust pressure of the steam turbine, and then compares the actual value of the intermediate pressure cylinder exhaust pressure with the current upper limit of the intermediate pressure cylinder exhaust pressure and the current lower limit of the intermediate pressure cylinder exhaust pressure respectively, and can determine the actual value of the intermediate pressure cylinder exhaust pressure when the actual value is greater than the current lower limit of the intermediate pressure cylinder exhaust pressure and less than the current When the upper limit is reached, the intermediate-pressure cylinder exhaust pressure setting value of the intermediate-pressure cylinder exhaust pressure regulator of the steam turbine is updated to the current intermediate-pressure cylinder exhaust pressure standard value, and the opening of the connecting pipe butterfly valve between the intermediate-pressure cylinder and the low-pressure cylinder of the steam turbine is adjusted based on the updated intermediate-pressure cylinder exhaust pressure regulator, and when the actual value of the intermediate-pressure cylinder exhaust pressure is less than or equal to the current intermediate-pressure cylinder exhaust pressure lower limit, or the actual value of the intermediate-pressure cylinder exhaust pressure is greater than or equal to the current intermediate-pressure cylinder exhaust pressure upper limit, the connecting pipe butterfly valve is controlled to close or open at a preset rate. It can not only automatically update the set value of the intermediate pressure cylinder exhaust pressure of the intermediate pressure cylinder exhaust pressure regulator during the heating period, reduce the workload of the operating personnel and reduce erroneous operations, but also control the connecting pipe butterfly valve to close or open at a preset rate to forcibly open and close the connecting pipe butterfly valve when the actual value of the intermediate pressure cylinder exhaust pressure deviates from the set value of the intermediate pressure cylinder exhaust pressure by a large amount, so as to prevent problems such as insufficient steam source pressure of the small steam turbine, overload of the last stage blades of the intermediate pressure cylinder, and excessively high exhaust temperature of the intermediate pressure cylinder caused by the excessive deviation of the actual value of the intermediate pressure cylinder exhaust pressure from the set value of the intermediate pressure cylinder exhaust pressure, thereby ensuring safe and economical operation of the steam turbine unit.

[0095] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0096] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0097] Figure 5 The schematic diagram of the structure of the medium pressure cylinder exhaust steam pressure control device provided by the embodiment of the present invention is shown. For the convenience of explanation, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0098] like Figure 5 As shown, the medium pressure cylinder exhaust steam pressure control device includes: a first processing module 51, a second processing module 52, a first control module 53 and a second control module 54.

[0099] The first processing module 51 is used to determine the current intermediate pressure cylinder exhaust pressure standard value, the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit of the steam turbine based on the current main steam flow of the steam turbine.

[0100] The second processing module 52 is used to obtain the actual value of the intermediate pressure cylinder exhaust pressure of the steam turbine, and compare the actual value of the intermediate pressure cylinder exhaust pressure with the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit respectively.

[0101] The first control module 53 is used to update the intermediate pressure cylinder exhaust pressure set value of the intermediate pressure cylinder exhaust pressure regulator of the steam turbine to the current intermediate pressure cylinder exhaust pressure standard value if the actual value of the intermediate pressure cylinder exhaust pressure is greater than the current intermediate pressure cylinder exhaust pressure lower limit and less than the current intermediate pressure cylinder exhaust pressure upper limit, and adjust the opening of the connecting pipe butterfly valve between the intermediate pressure cylinder and the low pressure cylinder of the steam turbine based on the updated intermediate pressure cylinder exhaust pressure regulator.

[0102] The second control module 54 is used to control the connecting pipe butterfly valve to close or open at a preset rate if the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure.

[0103] The embodiment of the present invention determines the current standard value of the intermediate pressure cylinder exhaust pressure of the steam turbine, the current upper limit of the intermediate pressure cylinder exhaust pressure and the current lower limit of the intermediate pressure cylinder exhaust pressure based on the current main steam flow of the steam turbine, and obtains the actual value of the intermediate pressure cylinder exhaust pressure of the steam turbine, and then compares the actual value of the intermediate pressure cylinder exhaust pressure with the current upper limit of the intermediate pressure cylinder exhaust pressure and the current lower limit of the intermediate pressure cylinder exhaust pressure respectively, and can determine the actual value of the intermediate pressure cylinder exhaust pressure when the actual value is greater than the current lower limit of the intermediate pressure cylinder exhaust pressure and less than the current When the pressure upper limit is reached, the set value of the intermediate-pressure cylinder exhaust pressure of the intermediate-pressure cylinder exhaust pressure regulator of the steam turbine is updated to the current standard value of the intermediate-pressure cylinder exhaust pressure, and the opening of the connecting pipe butterfly valve between the intermediate-pressure cylinder and the low-pressure cylinder of the steam turbine is adjusted based on the updated intermediate-pressure cylinder exhaust pressure regulator, and when the actual value of the intermediate-pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate-pressure cylinder exhaust pressure, or the actual value of the intermediate-pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate-pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to close or open at a preset rate. It can not only automatically update the set value of the intermediate pressure cylinder exhaust pressure of the intermediate pressure cylinder exhaust pressure regulator during the heating period, reduce the workload of the operating personnel and reduce erroneous operations, but also control the connecting pipe butterfly valve to close or open at a preset rate to forcibly open and close the connecting pipe butterfly valve when the actual value of the intermediate pressure cylinder exhaust pressure deviates from the set value of the intermediate pressure cylinder exhaust pressure by a large amount, so as to prevent problems such as insufficient steam source pressure of the small steam turbine, overload of the last stage blades of the intermediate pressure cylinder, and excessively high exhaust temperature of the intermediate pressure cylinder caused by the excessive deviation of the actual value of the intermediate pressure cylinder exhaust pressure from the set value of the intermediate pressure cylinder exhaust pressure, thereby ensuring safe and economical operation of the steam turbine unit.

[0104] In one possible implementation, the first processing module 51 can be used to determine the standard value of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow of the steam turbine based on the correspondence between the main steam flow and the standard value of the intermediate pressure cylinder exhaust pressure, recorded as the current standard value of the intermediate pressure cylinder exhaust pressure; determine the upper limit of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow of the steam turbine based on the correspondence between the main steam flow and the upper limit of the intermediate pressure cylinder exhaust pressure, recorded as the current upper limit of the intermediate pressure cylinder exhaust pressure; determine the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow of the steam turbine based on the correspondence between the main steam flow and the lower limit of the intermediate pressure cylinder exhaust pressure, recorded as the current lower limit of the intermediate pressure cylinder exhaust pressure.

[0105] In a possible implementation, the first processing module 51 can also be used to, for each main steam flow value, under heating conditions, lower the intermediate pressure cylinder exhaust pressure value from the intermediate pressure cylinder exhaust pressure basic value until the steam inlet regulating valve opening of the small turbine reaches a safe opening threshold, and record the intermediate pressure cylinder exhaust pressure value at this time as the intermediate pressure cylinder exhaust pressure standard value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure basic value is the intermediate pressure cylinder exhaust pressure value corresponding to the turbine under pure condensing conditions; each main steam flow value and each main steam flow value corresponding to the intermediate pressure cylinder exhaust pressure standard value are fitted to obtain the corresponding relationship between the main steam flow and the intermediate pressure cylinder exhaust pressure standard value.

[0106] In a possible implementation, the first processing module 51 can also be used to, for each main steam flow value, under heating conditions, start from the intermediate pressure cylinder exhaust pressure base value to adjust the intermediate pressure cylinder exhaust pressure value upward until the intermediate pressure cylinder exhaust temperature reaches the exhaust temperature safety threshold, and record the intermediate pressure cylinder exhaust pressure value at this time as the intermediate pressure cylinder exhaust pressure upper limit value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure base value is the intermediate pressure cylinder exhaust pressure value corresponding to the turbine under pure condensing conditions; each main steam flow value and each main steam flow value corresponding to the intermediate pressure cylinder exhaust pressure upper limit value are fitted to obtain the corresponding relationship between the main steam flow and the intermediate pressure cylinder exhaust pressure upper limit.

[0107] In a possible implementation, the first processing module 51 can also be used to, for each main steam flow value, under heating conditions, lower the intermediate pressure cylinder exhaust pressure value from the intermediate pressure cylinder exhaust pressure base value until the steam inlet regulating valve opening of the small turbine reaches the maximum opening threshold, and record the intermediate pressure cylinder exhaust pressure value at this time as the intermediate pressure cylinder exhaust pressure lower limit value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure base value is the intermediate pressure cylinder exhaust pressure value corresponding to the turbine under pure condensing conditions; each main steam flow value and the intermediate pressure cylinder exhaust pressure lower limit value corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the intermediate pressure cylinder exhaust pressure lower limit.

[0108] In one possible implementation, the preset rate includes a first preset rate and a second preset rate; the second control module 54 can be used to control the connecting pipe butterfly valve to close at the first preset rate if the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure; if the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, then control the connecting pipe butterfly valve to open at the second preset rate.

[0109] In one possible implementation, the second control module 54 can also be used to calculate the difference between the actual value of the intermediate pressure cylinder exhaust pressure and the current lower limit of the intermediate pressure cylinder exhaust pressure if the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, record it as the first difference, and determine the first preset rate based on the first difference; if the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, calculate the difference between the actual value of the intermediate pressure cylinder exhaust pressure and the current upper limit of the intermediate pressure cylinder exhaust pressure, record it as the second difference, and determine the second preset rate based on the second difference.

[0110] Figure 6 is a schematic diagram of a controller provided by an embodiment of the present invention. Figure 6 As shown, the controller 6 of this embodiment includes: a processor 60, a memory 61, and a computer program 62 stored in the memory 61 and executable on the processor 60. When the processor 60 executes the computer program 62, the steps in the above-mentioned embodiments of the method for controlling the exhaust steam pressure of the intermediate pressure cylinder are implemented, for example Figure 2 Alternatively, when the processor 60 executes the computer program 62, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 5 Functions of modules / units 51 to 54 are shown.

[0111] Exemplarily, the computer program 62 may be divided into one or more modules / units, one or more modules / units are stored in the memory 61 and executed by the processor 60 to implement the present invention. One or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 62 in the controller 6. For example, the computer program 62 may be divided into Figure 5 Modules / units 51 to 54 are shown.

[0112] The controller 6 may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art will appreciate that Figure 6 It is only an example of the controller 6 and does not constitute a limitation of the controller 6. The controller 6 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the controller may also include input and output devices, network access devices, buses, etc.

[0113] The processor 60 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0114] The memory 61 may be an internal storage unit of the controller 6, such as a hard disk or memory of the controller 6. The memory 61 may also be an external storage device of the controller 6, such as a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the controller 6. Further, the memory 61 may also include both an internal storage unit of the controller 6 and an external storage device. The memory 61 is used to store computer programs and other programs and data required by the controller. The memory 61 may also be used to temporarily store data that has been output or is to be output.

[0115] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0116] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0117] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0118] In the embodiments provided by the present invention, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0119] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0120] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0121] If the integrated module / unit 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 present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned embodiments of the medium-pressure cylinder exhaust steam pressure control method can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium.

[0122] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A method for controlling the exhaust steam pressure of an intermediate pressure cylinder, characterized in that: include: Based on the current main steam flow of the steam turbine, determine the current intermediate pressure cylinder exhaust pressure standard value, the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit of the steam turbine; Obtaining an actual value of the intermediate pressure cylinder exhaust pressure of the steam turbine, and comparing the actual value of the intermediate pressure cylinder exhaust pressure with a current intermediate pressure cylinder exhaust pressure upper limit and a current intermediate pressure cylinder exhaust pressure lower limit respectively; If the actual value of the intermediate pressure cylinder exhaust pressure is greater than the current intermediate pressure cylinder exhaust pressure lower limit and less than the current intermediate pressure cylinder exhaust pressure upper limit, the intermediate pressure cylinder exhaust pressure setting value of the intermediate pressure cylinder exhaust pressure regulator of the steam turbine is updated to the current intermediate pressure cylinder exhaust pressure standard value, and the opening of the connecting pipe butterfly valve between the intermediate pressure cylinder and the low pressure cylinder of the steam turbine is adjusted based on the updated intermediate pressure cylinder exhaust pressure regulator; If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to close or open according to a preset rate.

2. The method for controlling the exhaust steam pressure of the intermediate pressure cylinder according to claim 1, characterized in that: The method of determining the current intermediate pressure cylinder exhaust pressure standard value, the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit of the steam turbine based on the current main steam flow of the steam turbine includes: Based on the correspondence between the main steam flow rate and the standard value of the intermediate pressure cylinder exhaust pressure, determine the standard value of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow rate of the steam turbine, and record it as the current standard value of the intermediate pressure cylinder exhaust pressure; Based on the corresponding relationship between the main steam flow rate and the upper limit of the intermediate pressure cylinder exhaust pressure, the upper limit of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow rate of the steam turbine is determined, and recorded as the current upper limit of the intermediate pressure cylinder exhaust pressure; Based on the corresponding relationship between the main steam flow and the lower limit of the intermediate pressure cylinder exhaust pressure, the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to the current main steam flow of the steam turbine is determined and recorded as the current lower limit of the intermediate pressure cylinder exhaust pressure.

3. The method for controlling the exhaust steam pressure of the intermediate pressure cylinder according to claim 2, characterized in that: The process of determining the corresponding relationship between the main steam flow rate and the standard value of the intermediate pressure cylinder exhaust pressure includes: For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is adjusted downward from the intermediate pressure cylinder exhaust pressure base value until the steam inlet regulating valve opening of the small steam turbine reaches the safety opening threshold, and the intermediate pressure cylinder exhaust pressure value at this time is recorded as the intermediate pressure cylinder exhaust pressure standard value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure base value is the intermediate pressure cylinder exhaust pressure value corresponding to the steam turbine under pure condensing conditions; Each main steam flow value and the standard value of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the standard value of the intermediate pressure cylinder exhaust pressure.

4. The method for controlling the exhaust steam pressure of the intermediate pressure cylinder according to claim 2, characterized in that: The process of determining the corresponding relationship between the main steam flow rate and the upper limit of the intermediate pressure cylinder exhaust pressure includes: For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is adjusted upward from the intermediate pressure cylinder exhaust pressure base value until the intermediate pressure cylinder exhaust temperature reaches the exhaust temperature safety threshold, and the intermediate pressure cylinder exhaust pressure value at this time is recorded as the intermediate pressure cylinder exhaust pressure upper limit value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure base value is the intermediate pressure cylinder exhaust pressure value corresponding to the steam turbine under pure condensing conditions; Each main steam flow value and the upper limit value of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the upper limit of the intermediate pressure cylinder exhaust pressure.

5. The method for controlling the exhaust steam pressure of the intermediate pressure cylinder according to claim 2, characterized in that: The process of determining the corresponding relationship between the main steam flow rate and the lower limit of the intermediate pressure cylinder exhaust pressure includes: For each main steam flow value, under heating conditions, the intermediate pressure cylinder exhaust pressure value is adjusted downward from the intermediate pressure cylinder exhaust pressure base value until the opening of the steam inlet regulating valve of the small steam turbine reaches the maximum opening threshold, and the intermediate pressure cylinder exhaust pressure value at this time is recorded as the intermediate pressure cylinder exhaust pressure lower limit value corresponding to the main steam flow value, wherein the intermediate pressure cylinder exhaust pressure base value is the intermediate pressure cylinder exhaust pressure value corresponding to the steam turbine under pure condensing conditions; Each main steam flow value and the lower limit of the intermediate pressure cylinder exhaust pressure corresponding to each main steam flow value are fitted to obtain the corresponding relationship between the main steam flow and the lower limit of the intermediate pressure cylinder exhaust pressure.

6. The method for controlling the exhaust steam pressure of an intermediate pressure cylinder according to claim 1, characterized in that: The preset rate includes a first preset rate and a second preset rate; If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current intermediate pressure cylinder exhaust pressure lower limit, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current intermediate pressure cylinder exhaust pressure upper limit, the connecting pipe butterfly valve is controlled to close or open at a preset rate, including: If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to close at the first preset rate; If the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, the connecting pipe butterfly valve is controlled to open wider according to the second preset rate.

7. The method for controlling the exhaust steam pressure of an intermediate pressure cylinder according to claim 6, characterized in that: The process of determining the first preset rate is as follows: If the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, the difference between the actual value of the intermediate pressure cylinder exhaust pressure and the current lower limit of the intermediate pressure cylinder exhaust pressure is calculated and recorded as the first difference, and the first preset rate is determined according to the first difference; The process of determining the second preset rate is as follows: If the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure, the difference between the actual value of the intermediate pressure cylinder exhaust pressure and the current upper limit of the intermediate pressure cylinder exhaust pressure is calculated and recorded as the second difference, and the second preset rate is determined based on the second difference.

8. A medium pressure cylinder exhaust steam pressure control device, characterized in that: include: The first processing module is used to determine the current intermediate pressure cylinder exhaust pressure standard value, the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit of the steam turbine based on the current main steam flow of the steam turbine; The second processing module is used to obtain the actual value of the intermediate pressure cylinder exhaust pressure of the steam turbine, and compare the actual value of the intermediate pressure cylinder exhaust pressure with the current intermediate pressure cylinder exhaust pressure upper limit and the current intermediate pressure cylinder exhaust pressure lower limit respectively; The first control module is used to update the set value of the intermediate pressure cylinder exhaust pressure of the steam turbine to the current standard value of the intermediate pressure cylinder exhaust pressure if the actual value of the intermediate pressure cylinder exhaust pressure is greater than the current lower limit of the intermediate pressure cylinder exhaust pressure and less than the current upper limit of the intermediate pressure cylinder exhaust pressure, and adjust the opening of the butterfly valve of the connecting pipe between the intermediate pressure cylinder and the low pressure cylinder of the steam turbine based on the updated intermediate pressure cylinder exhaust pressure regulator; The second control module is used to control the connecting pipe butterfly valve to close or open at a preset rate if the actual value of the intermediate pressure cylinder exhaust pressure is less than or equal to the current lower limit of the intermediate pressure cylinder exhaust pressure, or the actual value of the intermediate pressure cylinder exhaust pressure is greater than or equal to the current upper limit of the intermediate pressure cylinder exhaust pressure.

9. A controller, characterized in that: The method comprises a memory and a processor, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method as claimed in any one of claims 1 to 7 are implemented.

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