A multi-parameter steam supply system and method

Abstract

The present application discloses a multi-parameter steam supply system and method, and relates to the field of steam supply technology. The present application includes a heating bypass, a heating reheater and a peak-shaving reheater. The inlet of the heating bypass is connected to the outlet main steam pipeline of the boiler, and the heating bypass is used to provide high-pressure steam; the inlet of the heating reheater is connected to the outlet of the heating bypass through a pipeline, and the outlet of the heating reheater is connected to the external steam supply end; the heating reheater is used to heat the steam provided by the heating bypass when the steam supply system is in a low-load condition; the inlet of the peak-shaving reheater is connected to the outlet of the high-pressure cylinder through a pipeline, and the outlet of the peak-shaving reheater is connected to the inlet of the medium-pressure cylinder. The present application can meet the steam supply system's requirements for multiple steam supply parameters under low-load conditions, especially high-pressure and large-flow steam supply requirements, thereby greatly improving the steam supply effect and operational flexibility of the steam supply system.

Description

Technical Field

[0001] The present application relates to the technical field of steam supply, and in particular to a multi-parameter steam supply system and method. Background Art

[0002] As the energy structure changes, the installed capacity and proportion of wind power and photovoltaic power are gradually increasing. Coal-fired power generation units will inevitably participate in deep peak regulation. In order to better supply steam, a steam supply system is needed.

[0003] As the load of coal-fired power generation units decreases, the existing steam supply methods such as high-pressure cylinder perforation extraction, reheat system extraction, high and low bypass combined heating, etc. cannot simultaneously meet the steam requirements of multiple parameters, large flow and ultra-low load. That is, in the existing technology, the steam supply system has insufficient steam extraction pressure and steam extraction volume under low load conditions, which affects the steam supply effect of the steam supply system. Summary of the invention

[0004] The main purpose of the present application is to provide a multi-parameter steam supply system and method, aiming to solve the technical problem in the prior art that under low load conditions, the steam extraction pressure and steam extraction volume of the steam supply system are insufficient, thereby affecting the steam supply effect of the steam supply system.

[0005] To achieve the above objectives, in a first aspect, the present application provides a multi-parameter steam supply system, comprising:

[0006] A heating bypass, the inlet of which is connected to the outlet main steam pipeline of the boiler, and the heating bypass is used to provide high-pressure steam;

[0007] A heating reheater, wherein the inlet of the heating reheater is connected to the outlet of the heating bypass through a pipeline, and the outlet of the heating reheater is connected to the external steam supply end; the heating reheater is used to heat the steam provided by the heating bypass when the steam supply system is in a low-load condition;

[0008] A peak shaving reheater, wherein the inlet of the peak shaving reheater is connected to the outlet of the high-pressure cylinder through a pipeline, and the outlet of the peak shaving reheater is connected to the inlet of the medium-pressure cylinder; the peak shaving reheater is used to heat the steam discharged from the high-pressure cylinder when the steam supply system is in peak shaving condition.

[0009] Optionally, it also includes a flow distribution station, which is connected to the inlet of the peak-shaving reheater through a pipeline, and the flow distribution station is used to adjust the flow ratio of steam entering the peak-shaving reheater and entering the heat supply reheater.

[0010] Optionally, it also includes a steam supply mode switching valve and a first check valve;

[0011] The first check valve and the steam supply mode switching valve are sequentially connected between the outlet of the heating bypass and the inlet of the flow distribution station through pipelines;

[0012] The steam supply mode switching valve is used to switch between a high-load steam supply mode and a low-load steam supply mode.

[0013] Optionally, it further comprises a multi-parameter steam supply regulating station, wherein the multi-parameter steam supply regulating station is arranged at the external steam supply end;

[0014] The multi-parameter steam supply regulating station is used to regulate the steam supply parameters for external steam supply.

[0015] Optionally, it further comprises a steam supply shut-off valve and an overpressure protection valve; the steam supply shut-off valve is arranged between the heating reheater and the multi-parameter steam supply regulating station, and the overpressure protection valve is arranged at the outlet end of the heating reheater;

[0016] The steam supply shut-off valve is used to connect or disconnect the external steam supply end;

[0017] The overpressure protection valve is used to protect the heating reheater and the pipeline.

[0018] Optionally, it further comprises an overflow regulating station, which is arranged at the outlet end of the heat supply reheater and connected to the inlet of the medium pressure cylinder through a pipeline, and the overflow regulating station is arranged in parallel with the multi-parameter steam supply regulating station;

[0019] The overflow regulating station is used to transport excess steam to the intermediate pressure cylinder to perform work, so as to reduce the fluctuation of steam consumption of the steam supply system.

[0020] Optionally, it also includes a second check valve and an emergency discharge valve;

[0021] The second check valve is arranged at the inlet end of the overflow regulating station; the emergency discharge valve is arranged at the inlet end of the steam supply shut-off valve;

[0022] The second check valve is used to prevent the steam from flowing back from the overflow regulating station;

[0023] The emergency discharge valve is used to reduce the steam overflowing from the overflow regulating station to prevent the demand for external steam from decreasing and excessive steam passing through the overflow regulating station causing unbalanced axial thrust of the steam turbine generator set.

[0024] Optionally, it also includes a pressure relief valve, a bypass shut-off valve and a maintenance shut-off valve;

[0025] The pressure relief valve is arranged between the heating bypass and the heating reheater; the bypass shut-off valve is arranged at the inlet end of the heating bypass; the maintenance shut-off valve is arranged at the outlet end of the heating bypass;

[0026] The pressure relief valve is used to protect the inlet pipeline of the heating reheater to prevent the pressure regulation of the heating bypass from being out of balance and causing pipeline overpressure;

[0027] The bypass shut-off valve is used to cut off the inlet pipeline of the heating bypass;

[0028] The inspection shut-off valve is used to cut off the outlet pipeline of the heating bypass so as to inspect the heating bypass.

[0029] In a second aspect, a multi-parameter steam supply method is applied to the steam supply system described above, and the steam supply method comprises:

[0030] Based on the heating request information, the outlet pressure of the heating reheater is obtained;

[0031] comparing the outlet pressure of the heat supply reheater with the heat supply pressure of the steam supply system;

[0032] When the outlet pressure of the heating reheater is lower than the heating pressure of the steam supply system, the flow distribution station cooperates with the heating bypass to adjust, and the steam supply mode is switched through the heating mode switching valve, so that the outlet pressure of the heating reheater is higher than the heating pressure of the steam supply system;

[0033] When the outlet pressure of the heat supply reheater is greater than the heat supply pressure of the steam supply system, the steam supply system is controlled to supply steam to the outside.

[0034] Optionally, when the outlet pressure of the heat supply reheater is lower than the heat supply pressure of the steam supply system, the flow distribution station cooperates with the high-pressure heat supply bypass to adjust, and the steam supply mode is switched by the heat supply mode switching valve, so that the outlet pressure of the heat supply reheater is higher than the heat supply pressure of the steam supply system, including:

[0035] Obtain the exhaust parameters of the high-pressure cylinder, the inlet flow rate of the peak-shaving reheater, and the inlet flow rate of the heating reheater;

[0036] Based on the exhaust parameters of the high-pressure cylinder, the inlet flow rate of the peak-shaving reheater, and the inlet flow rate of the heating reheater, an outlet setting value of the heating bypass and an inlet flow setting value of the peak-shaving reheater are obtained;

[0037] Based on the outlet set value of the heat supply bypass and the inlet flow set value of the peaking reheater, stabilize the inlet flow of the flow distribution station and the inlet flow of the heat supply reheater;

[0038] Based on the inlet flow of the flow distribution station and the inlet flow of the heating reheater, the flow distribution station is coordinated with the heating bypass for adjustment, and the steam supply mode is switched through the heating mode switching valve so that the outlet pressure of the heating reheater is greater than the heating pressure of the steam supply system, and steam can be supplied to the outside through the heating bypass, the heating reheater and the steam supply regulating station.

[0039] Through the above technical solution, the present application can at least achieve the following beneficial effects:

[0040] The present application provides a multi-parameter steam supply system and method, including a heating bypass, a heating reheater and a peak-shaving reheater, wherein the inlet of the heating bypass is connected to the outlet main steam pipeline of the boiler, and the heating bypass is used to provide steam; the inlet of the heating reheater is connected to the outlet of the heating bypass through a pipeline, and the outlet of the heating reheater is connected to the external steam supply end; the heating reheater is used to heat the steam provided by the heating bypass when the steam supply system is in a low-load condition; the inlet of the peak-shaving reheater is connected to the outlet of the high-pressure cylinder through a pipeline, and the outlet of the peak-shaving reheater is connected to the inlet of the medium-pressure cylinder; the peak-shaving reheater is used to heat the steam discharged from the high-pressure cylinder when the steam supply system is in a peak-shaving condition.

[0041] That is, when the steam supply system is in a low-load condition and supplies steam to the outside, the steam provided by the heat bypass enters the heat supply reheater, and the heat supply reheater heats the high-pressure and low-temperature reheat steam into high-pressure and high-temperature reheat steam before it is transported to the external steam supply end for external steam supply; the peak-shaving reheater heats the low-pressure and low-temperature reheat steam at the outlet of the high-pressure cylinder into low-pressure and high-temperature reheat steam before it is transported to the medium-pressure cylinder for work. That is, since the steam supply system of the present application is provided with a heat supply reheater and a peak-shaving reheater, the heat supply reheater can heat the high-pressure and low-temperature reheat steam into high-pressure and high-temperature reheat steam, and the peak-shaving reheater can heat the low-pressure and low-temperature reheat steam into low-pressure and high-temperature reheat steam, so that the temperature of the steam can be increased, thereby greatly increasing the steam extraction pressure and steam extraction volume of the steam supply system, and further greatly improving the steam supply effect and heating flexibility of the steam supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0043] Figure 1 A schematic diagram of a multi-parameter steam supply system provided in this embodiment;

[0044] Figure 2 A schematic diagram of a heating mode provided in this embodiment;

[0045] Figure 3 A schematic diagram of another heating mode provided in this embodiment;

[0046] Figure 4 A flow chart of a multi-parameter steam supply method provided in this embodiment;

[0047] Figure 5 A flowchart of a specific execution method of step S12 provided in this embodiment.

[0048] Figure numerals: 1. first check valve; 2. steam supply mode switching valve; 3. flow distribution station; 4. pressure relief valve; 5. heating reheater; 6. peak-shaving reheater; 7. overpressure protection valve; 8. second check valve; 9. emergency discharge valve; 10. steam supply shut-off valve; 11. parameter steam supply regulating station; 12. overflow regulating station; 13. bypass shut-off valve; 14. heating bypass; 15. maintenance shut-off valve.

[0049] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0052] With the change of energy structure, the installed capacity and proportion of wind power and photovoltaic power are gradually increasing. Coal-fired power generation units will inevitably participate in deep peak regulation. With the reduction of the load of coal-fired power generation units, the existing steam supply methods such as high-pressure cylinder drilling extraction, reheat system extraction, high and low bypass combined heating cannot meet the steam requirements of multiple parameters, large flow and ultra-low load at the same time. For example: the steam extraction of steam by drilling holes in the steam turbine body has limited steam extraction; that is, the size and position of the steam extraction port of the steam turbine have been determined by design and manufacturing, and the steam extraction volume and extraction parameters are limited by the flow field of the steam turbine, and the steam extraction volume cannot be expanded. The reheat system extracts steam, and the extraction pressure is low under low load conditions; that is, the high-pressure cylinder exhaust pressure and temperature are the controlled objects to protect the safe operation of the unit. Under any operating conditions, they must be strictly limited to the range allowed by the manufacturer. When the unit load is reduced, especially under the condition of less than 40% THA, the reheat steam pressure does not meet the requirements of high-pressure steam supply. In addition, the extraction volume of low-temperature reheat steam is limited by the area of ​​the boiler reheater, and the needs of steam users cannot be guaranteed. High and low bypass combined heating; that is, the high and low bypass combined heating technology solves the problem of small extraction volume of the reheat system, but cannot solve the pain point of low exhaust pressure of the high-pressure cylinder under low load conditions. The adjustment and operation of the high-pressure bypass valve are still limited by the exhaust pressure and temperature of the high-pressure cylinder. Therefore, the high and low bypass combined heating technology cannot meet the requirements of high-pressure steam users, and the low-load extraction pressure is low and the extraction volume is insufficient.

[0053] In summary, at present, under low load conditions, the steam extraction pressure and steam extraction volume of the steam supply system are low, which affects the technical problem of the steam supply effect of the steam supply system.

[0054] In order to solve the above technical problems, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0055] like Figure 1 As shown, this embodiment provides a multi-parameter steam supply system, including a heating bypass 14, a heating reheater 5 and a peak-shaving reheater 6, the inlet of the heating bypass 14 is connected to the outlet main steam pipeline of the boiler, and the heating bypass 14 is used to provide steam; the inlet of the heating reheater 5 is connected to the outlet of the heating bypass 14 through a pipeline, and the outlet of the heating reheater 5 is connected to the external steam supply end; the heating reheater 5 is used to heat the steam provided by the heating bypass 14 when the steam supply system is in a low-load condition; the inlet of the peak-shaving reheater 6 is connected to the outlet of the high-pressure cylinder through a pipeline, and the outlet of the peak-shaving reheater 6 is connected to the inlet of the medium-pressure cylinder; the peak-shaving reheater 6 is used to heat the steam discharged from the high-pressure cylinder when the steam supply system is in a peak-shaving condition.

[0056] In this embodiment, in the conventional steam supply system, a high-pressure bypass, a high-pressure cylinder, a medium-pressure cylinder, a feed water pump and a boiler are provided. Although the high-pressure bypass can increase the pressure of the steam, the pressure of the steam increased by the high-pressure bypass is limited, and opening the high-pressure bypass for a long time will also cause erosion to the steam supply system and damage the steam supply system. The improved steam supply system adds a heating bypass 14, a heating reheater 5 and a peak-shaving reheater 6; wherein, the heating bypass 14 is also called a high-pressure heating bypass, and the heating bypass 14 is the main source of high-pressure steam for the unit under low-load conditions. When the steam user demand changes (when the required steam pressure is higher than the existing steam supply pressure), the user demand can be met by adjusting the outlet pressure of the heating bypass 14. The heating reheater 5 heats the steam of the heating bypass 14 under low-load conditions, and heats the high-pressure and low-temperature reheat steam into high-pressure and high-temperature reheat steam; and heats the exhaust steam of the high-pressure cylinder under high-load conditions. The peak shaving reheater 6 is used to heat the low-pressure and low-temperature reheated steam from the outlet of the high-pressure cylinder of the steam turbine during deep peak shaving. The peak shaving reheater 6 heats the low-pressure and low-temperature reheated steam into low-pressure and high-temperature reheated steam. When the steam supply system is in a low-load condition and supplies steam to the outside, the steam provided by the heat supply bypass 14 enters the heat supply reheater 5, and the heat supply reheater 5 heats the high-pressure and low-temperature reheated steam into high-pressure and high-temperature reheated steam before it is transported to the steam supply end for external steam supply; the peak shaving reheater 6 heats the low-pressure and low-temperature reheated steam into low-pressure and high-temperature reheated steam before it is transported to the medium-pressure cylinder for work. That is, since the steam supply system of the present application is provided with a heating reheater 5 and a peak-shaving reheater 6, the heating reheater 5 can heat the high-pressure and low-temperature reheat steam into high-pressure and high-temperature reheat steam, and the peak-shaving reheater 6 can heat the low-pressure and low-temperature reheat steam into low-pressure and high-temperature reheat steam. This can increase the temperature of the steam, thereby greatly increasing the steam extraction pressure and steam extraction volume of the steam supply system, and further greatly improving the steam supply effect of the steam supply system.

[0057] In some embodiments, Figure 1 As shown, the steam supply system also includes a flow distribution station 3, which is connected between the outlet of the heat supply bypass 14 and the inlet of the peak-shaving reheater 6 through a pipeline, and the flow distribution station 3 is used to adjust the flow ratio of the steam entering the peak-shaving reheater 6 and the steam entering the heat supply reheater 5.

[0058] In this embodiment, the flow distribution station 3 is used to adjust the steam flow ratio entering the peak-shaving reheater 6 and the heating reheater 5. When the heating bypass 14 is not put into use, the flow distribution station 3 adjusts the steam flow entering the peak-shaving reheater 6 so that the ratio of the steam flow of the peak-shaving reheater 6 and the heating reheater 5 is equal to the ratio of their heat exchange areas, so as to ensure that one reheater does not overheat due to insufficient flow. Specifically, the heating area S of the peak-shaving reheater 6 is TZThe basic design idea is to meet the deep peak load L of the steam turbine generator set (the common deep peak load range is 20%-50%). For a steam turbine generator set with a deep peak load L, the peak reheater 6 can be designed based on the heat and mass balance of the reheat steam system at the deep peak load L of the unit. The area S of the peak reheater 6 TZ The design pressure and design temperature of the peak load reheater 6 are the same as those of the reheater at the design condition of the unit. The design idea of ​​the heating area of ​​the heating reheater 5 is to first design the overall reheater heating surface area S of the steam turbine generator unit at the design condition point. zr , using the heating surface area S of the integral reheater zr Subtract the heating area S of the peak reheater 6 TZ , the heating area S of the heating reheater 5 can be obtained gr The design pressure of the heating reheater 5 is related to the maximum steam supply pressure (future maximum steam supply pressure), and can be determined as no less than 1.25 times the maximum steam supply pressure. The design temperature is the same as the design temperature of the reheater when the unit is in the design condition. By adjusting the steam flow ratio entering the peak-shaving reheater 6 and the heating reheater 5 through the flow distribution station 3, it is possible to avoid overheating of the peak-shaving reheater 6 or the heating reheater 5 due to insufficient flow, thereby better ensuring the normal operation of the steam supply system and providing better steam supply to the outside.

[0059] In some embodiments, Figure 1 As shown, the steam supply system also includes a steam supply mode switching valve 2 and a first check valve 1; the first check valve 1 and the steam supply mode switching valve 2 are connected in sequence between the outlet of the heat supply reheater 5 and the inlet of the flow distribution station 3 through pipelines; the steam supply mode switching valve 2 is used to switch between the first load steam supply mode and the second load steam supply mode; wherein the first load steam supply mode is a high load steam supply mode; the second load steam supply mode is a low load steam supply mode.

[0060] In this embodiment, the steam supply mode switching valve 2 connects the existing reheat cold section (the inlet of the flow distribution station 3) and the inlet of the heating reheater 5 (the outlet of the heating bypass 14) pipeline. The steam supply mode switching valve 2 is used to switch the working mode of the heating system. When the unit load is high, the heating bypass 14 is not put into use, the steam supply mode switching valve 2 is opened, the exhaust steam pressure of the high-pressure cylinder meets the heating requirements, and after the main steam passes through the high-pressure cylinder, it directly supplies steam to the outside through the heating reheater 5, and the excess steam overflows to the inlet of the medium-pressure cylinder; one way passes through the flow distribution station 3 and the peak-shaving reheater 6, and after merging with the steam from the overflow regulating station 12, it is sent to the medium-pressure cylinder to do work. When the unit is in deep peak load regulation (low load condition), the heating bypass 14 is put into operation, the steam supply mode switching valve 2 is closed, and the exhaust pressure of the high-pressure cylinder does not meet the heating requirements. A part of the main steam passes through the heating bypass 14, and after being heated by the heating reheater 5, it is supplied to the outside, and the excess steam overflows to the inlet of the medium-pressure cylinder; the other part of the main steam is converted into low-pressure and low-temperature reheat steam after working in the high-pressure cylinder, and after being heated by the flow distribution station 3 and the peak load reheater 6, it is combined with the steam from the overflow regulating station 12 and sent to the medium-pressure cylinder to work; therefore, by setting the steam supply mode switching valve 2, the steam supply mode of different load conditions can be controlled more conveniently and efficiently. The check valve is used to prevent the high-pressure and low-temperature reheat steam at the outlet of the heating bypass 14 from flowing to the low-pressure and low-temperature reheat steam.

[0061] In some embodiments, Figure 1 As shown, the steam supply system further includes a multi-parameter steam supply regulating station 11, which is arranged at the external steam supply end; the multi-parameter steam supply regulating station 11 is used to adjust the steam supply parameters of the external steam supply.

[0062] In this embodiment, the multi-parameter steam supply regulating station 11 is used to finely adjust the steam supply parameters to meet the personalized needs of users. The upper limit of the user's steam pressure is the outlet pressure of the heating bypass 14; the upper limit of the user's steam temperature is the reheat steam temperature of the unit. The steam supply parameters within the limits of the steam pressure and temperature can be achieved by setting corresponding temperature and pressure reduction regulating devices in the multi-parameter steam supply regulating station 11; by setting the multi-parameter steam supply regulating station 11, the user's needs for different steam parameters can be better met.

[0063] In some embodiments, Figure 1 As shown, the steam supply system also includes a steam supply shut-off valve 10 and an overpressure protection valve 7; the steam supply shut-off valve 10 is arranged between the heating reheater 5 and the multi-parameter steam supply regulating station 11, and the overpressure protection valve 7 is arranged at the outlet end of the heating reheater 5; the steam supply shut-off valve 10 is used to connect or disconnect the external steam supply end; the overpressure protection valve 7 is used to protect the heating reheater 5 and the pipeline.

[0064] In this embodiment, the overpressure protection valve 7 is used to protect the heating reheater 5 from overpressure caused by the outlet water spraying temperature adjustment and the pipeline overpressure caused by the sudden cutoff of external steam supply, thereby protecting the heating reheater 5 and the corresponding pipeline. The steam supply shut-off valve 10 is used as the main steam supply valve to cut off the steam supply, so that it is easier to control whether the multi-parameter steam supply regulating station 11 supplies steam to the outside.

[0065] In some embodiments, Figure 1 As shown, the steam supply system also includes an overflow regulating station 12, which is arranged at the outlet end of the heat supply reheater 5, and the overflow regulating station 12 is arranged in parallel with the multi-parameter steam supply regulating station 11; the overflow regulating station 12 is used to transport excess steam to the intermediate pressure cylinder to perform work, so as to reduce the steam consumption fluctuation of the steam supply system.

[0066] In this embodiment, the overflow regulating station 12 is used to adjust the fluctuation of steam consumption. When the external steam demand suddenly decreases, the excess steam can be sent to the intermediate pressure cylinder of the steam turbine generator set to perform work after the pressure is adjusted through the overflow regulating station 12, thereby reducing the impact of steam fluctuations on the steam supply system. When the heating bypass 14 is not put into use, the steam is directly sent to the intermediate pressure cylinder of the steam turbine generator set to perform work through the overflow regulating station 12 without adjusting the pressure; in this way, the utilization rate of steam can be greatly improved through the overflow regulating station 12.

[0067] In some embodiments, Figure 1 As shown, the steam supply system also includes a second check valve 8 and an emergency discharge valve 9; the second check valve 8 is arranged at the inlet end of the overflow regulating station 12; the emergency discharge valve 9 is arranged at the inlet end of the steam supply shut-off valve; the second check valve 8 is used to prevent the steam from flowing back from the overflow regulating station 12; the emergency discharge valve 9 is used to reduce the steam overflowing from the overflow regulating station 12 to prevent the demand for external steam from decreasing, and the excessive amount of steam passing through the overflow regulating station causes an unbalanced axial thrust of the steam turbine generator set.

[0068] In this embodiment, the second check valve 8 is used to prevent the steam from flowing back from the overflow regulating station 12, so that the steam can be further better utilized and the steam supply system can be protected. The emergency discharge valve 9 is used to prevent the steam demand from decreasing. When the amount of steam passing through the overflow regulating station 12 is too much and causes the axial thrust of the steam turbine generator set to be unbalanced, the emergency discharge valve 9 can be opened to reduce the overflow, thereby greatly improving the safety of the steam supply system.

[0069] In some embodiments, Figure 1As shown, the steam supply system also includes a pressure relief valve 4, a bypass shut-off valve 13 and a maintenance shut-off valve 15; the pressure relief valve 4 is arranged between the heating bypass 14 and the heating reheater 5; the bypass shut-off valve 13 is arranged at the inlet end of the heating bypass 14; the maintenance shut-off valve 15 is arranged at the outlet end of the heating bypass 14; the pressure relief valve 4 is used to protect the inlet pipeline of the heating reheater 5 to prevent the pressure regulation of the heating bypass 14 from being out of balance and causing pipeline overpressure; the bypass shut-off valve 13 is used to cut off the inlet pipeline of the heating bypass 14; the maintenance shut-off valve 15 is used to cut off the outlet pipeline of the heating bypass 14 to inspect the heating bypass 14.

[0070] In this embodiment, the pressure relief valve 4 is used to protect the inlet pipeline of the heating reheater 5 and prevent the pipeline overpressure caused by the pressure regulation disorder of the heating bypass 14. Therefore, the pressure relief valve 4 can protect the inlet pipeline of the heating reheater 5 and the corresponding pipeline of the heating bypass 14. The bypass shut-off valve 13 is used to cut off the pipeline of the heating bypass 14 during the non-steam supply period to prevent leakage caused by long-term flushing of the heating bypass 14. At the same time, it cooperates with the maintenance shut-off valve 15 to isolate the heating bypass 14 for maintenance of the heating bypass 14. The inlet of the heating bypass 14 is connected to the main steam pipeline at the boiler outlet and isolated by the bypass shut-off valve 13. The outlet of the heating bypass 14 is connected to the inlet of the heating reheater 5 and isolated by the maintenance shut-off valve 15. Therefore, the bypass shut-off valve 13 and the maintenance shut-off valve 15 can more conveniently control the on and off of the heating bypass 14 and make it easier to repair the heating bypass 14.

[0071] Based on the above heating system, the heating system mainly has the following working modes:

[0072] like Figure 2 As shown, a heating mode is given, which shows the situation where the unit does not supply steam to the outside. In this mode, the heating bypass 14 is not put into operation, the multi-parameter steam supply regulating station 11 is not put into operation, the flow distribution station 3 is put into operation, the overflow regulating station 12 is opened, the steam supply mode switching valve 2 is opened, the bypass shut-off valve 13, the maintenance shut-off valve 15, and the steam supply shut-off valve 10 are in a closed state. Part of the steam flows through the high-pressure cylinder, the steam supply mode switching valve 2, the check valve, the heating reheater 5, the check valve, the overflow regulating station 12 and the medium-pressure cylinder in sequence, and the other part of the steam flows through the high-pressure cylinder, the flow distribution station 3, the peak-shaving reheater 6 and the medium-pressure cylinder in sequence.

[0073] like Figure 3 As shown, another mode is given, which shows the situation of the unit supplying heat to the outside under high load. In this mode, the heating bypass 14 is not put into operation, the multi-parameter steam supply regulating station 11 is put into operation, the overflow regulating station 12 is opened, the flow distribution station 3 is put into operation, the steam supply mode switching valve 2 and the steam supply shut-off valve 10 are opened, and the bypass shut-off valve 13 and the maintenance shut-off valve 15 are closed.

[0074] like Figure 1 As shown, another mode is given, which shows the situation of the unit supplying heat to the outside at low load. The heating bypass 14 is put into operation, the multi-parameter steam supply regulating station 11 is put into operation, the overflow regulating station 12 is opened, the flow distribution station 3 is put into operation, the bypass shut-off valve 13, the maintenance shut-off valve 15 and the steam supply shut-off valve 10 are opened, and the steam supply mode switching valve 2 is in a closed state.

[0075] In another embodiment, if Figure 4 As shown, a multi-parameter steam supply method is provided, which is applied to the steam supply system described above. The steam supply method includes the following steps:

[0076] S10: Based on the heating request information, the outlet pressure of the heating reheater is obtained.

[0077] In the specific implementation process, after the steam supply system receives the heating request, it indicates that steam needs to be supplied to the outside. At this time, the outlet pressure of the heating reheater 5 is first obtained.

[0078] S11: Compare the outlet pressure of the heat supply reheater with the heat supply pressure of the steam supply system.

[0079] In the specific implementation process, the heating pressure of the steam supply system can be obtained according to the actual heating request information. When the outlet pressure of the heating reheater 5 is obtained in step S10, the outlet pressure of the heating reheater 5 is compared with the heating pressure of the steam supply system to confirm whether steam can be supplied to the outside.

[0080] S12: When the outlet pressure of the heating reheater is lower than the heating pressure of the steam supply system, the flow distribution station is coordinated with the heating bypass for adjustment, and the steam supply mode is switched through the heating mode switching valve, so that the outlet pressure of the heating reheater is higher than the heating pressure of the steam supply system.

[0081] In the specific implementation process, if the outlet pressure of the heating reheater 5 is greater than or equal to the heating pressure of the steam supply system, steam is directly supplied to the outside; if the outlet pressure of the heating reheater 5 is less than the heating pressure of the steam supply system, it means that the outlet pressure of the heating reheater 5 is insufficient. Therefore, it is necessary to increase the outlet pressure of the heating reheater 5 until the outlet pressure of the heating reheater 5 is greater than the heating pressure of the steam supply system.

[0082] S13: When the outlet pressure of the heat supply reheater 5 is greater than the heat supply pressure of the steam supply system, the steam supply system is controlled to supply steam to the outside.

[0083] In the specific implementation process, when the outlet pressure of the heating reheater 5 is greater than the heating pressure of the steam supply system, it means that steam can be supplied to the outside. At this time, it is only necessary to control the steam supply system to supply steam to the outside.

[0084] In some embodiments, Figure 5 As shown, the specific steps of step S12 are given, that is, when the outlet pressure of the heating reheater 5 is less than the heating pressure of the steam supply system, the outlet pressure of the heating reheater 5 is adjusted by the flow distribution station 3 in coordination with the high-pressure heating bypass, and the outlet pressure of the heating reheater 5 is adjusted by the heating mode switching valve, so that the outlet pressure of the heating reheater 5 is greater than the heating pressure of the steam supply system, including:

[0085] S121: Obtain the exhaust parameters of the high-pressure cylinder, the inlet flow rate of the peak-shaving reheater 6, and the inlet flow rate of the heating reheater 5.

[0086] During the specific implementation process, when the outlet pressure of the heating reheater 5 is lower than the heating pressure of the steam supply system, the high-pressure cylinder exhaust parameters (temperature and pressure), the inlet flow of the peak-shaving reheater 6 and the inlet flow of the heating reheater 5 are obtained.

[0087] S122: Based on the exhaust parameters of the high-pressure cylinder, the inlet flow of the peak-shaving reheater 6 and the inlet flow of the heating reheater 5, the outlet setting value of the heating bypass 14 and the inlet flow setting value of the peak-shaving reheater 6 are obtained.

[0088] In the specific implementation process, the outlet set value of the heating bypass 14 (high-pressure cylinder exhaust steam temperature and pressure) is input, the inlet flow set value of the peak-shaving reheater 6 is input, and then the heating bypass 14 is automatically put into operation (the so-called automatic putting of the heating bypass 14 means that the exhaust steam pressure and temperature at the outlet of the high-pressure cylinder heating bypass 14 automatically reach the set value), and the flow distribution station 3 is automatically put into operation (that is, the flow distribution station 3 automatically reaches the set value).

[0089] S123: Based on the outlet setting value of the heat supply bypass 14 and the inlet flow setting value of the peak shaving reheater 6, stabilize the inlet flow of the flow distribution station 3 and the inlet flow of the heat supply reheater 5.

[0090] During the specific implementation process, based on the outlet set value of the heating bypass 14 and the inlet flow set value of the peak shaving reheater 6, the maintenance shut-off valve 15 is opened, the bypass shut-off valve 13 is slowly opened, and the steam supply mode switching valve 2 is slowly closed to ensure that the inlet flow of the heating reheater 5 remains unchanged, and the flow distribution station 3 ensures that the inlet flow of the peak shaving reheater 6 remains unchanged.

[0091] S124: Based on the inlet flow of the flow distribution station and the inlet flow of the heating reheater, the flow distribution station and the heating bypass are coordinated to adjust, and the steam supply mode is switched through the heating mode switching valve, so that the outlet pressure of the heating reheater is greater than the heating pressure of the steam supply system.

[0092] During the specific implementation process, the steam supply mode switching valve 2 sends a signal that the steam supply mode switching valve 2 is closed, the flow distribution station 3 is fully opened and exits the automatic mode, and then the inlet pressure of the medium-pressure cylinder is obtained, so that the overflow regulating station 12 is automatically put into operation, and the heating bypass 14 inputs the heating pressure setting value. The heating bypass 14 is automatically put into operation to increase the pressure of the heating reheater 5 system, and then the overflow regulating station 12 automatically adjusts the outlet pressure to meet the steam confluence with the peak-shaving reheater 6, and then opens the heating shut-off valve, so that the multi-parameter steam supply regulating station 11 is put into use to supply steam to the outside.

[0093] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A multi-parameter steam supply system, characterized in that: include: A heating bypass, the inlet of which is connected to the outlet main steam pipeline of the boiler, and the heating bypass is used to provide steam; A heating reheater, wherein the inlet of the heating reheater is connected to the outlet of the heating bypass through a pipeline, and the outlet of the heating reheater is connected to the external steam supply end; the heating reheater is used to heat the steam provided by the heating bypass when the steam supply system is in a low-load condition; A peak shaving reheater, wherein the inlet of the peak shaving reheater is connected to the outlet of the high-pressure cylinder through a pipeline, and the outlet of the peak shaving reheater is connected to the inlet of the medium-pressure cylinder; the peak shaving reheater is used to heat the steam discharged from the high-pressure cylinder when the steam supply system is in a peak shaving condition; A flow distribution station, the flow distribution station is arranged on the inlet pipeline of the peak shaving reheater, and the flow distribution station is used to adjust the flow ratio of the steam entering the peak shaving reheater and the steam entering the heating reheater; A steam supply mode switching valve and a first check valve, wherein the first check valve and the steam supply mode switching valve are sequentially connected between the inlet of the heating reheater and the inlet of the flow distribution station through pipelines; The steam supply mode switching valve is used to switch between the first load steam supply mode and the second load steam supply mode; The multi-parameter steam supply method applied to the multi-parameter steam supply system comprises the following steps: Based on the heating request information, the outlet pressure of the heating reheater is obtained; comparing the outlet pressure of the heat supply reheater with the heat supply pressure of the steam supply system; When the outlet pressure of the heating reheater is lower than the heating pressure of the steam supply system, the flow distribution station cooperates with the heating bypass to adjust, and the steam supply mode is switched through the heating mode switching valve, so that the outlet pressure of the heating reheater is higher than the heating pressure of the steam supply system; When the outlet pressure of the heat supply reheater is greater than the heat supply pressure of the steam supply system, the steam supply system is controlled to supply steam to the outside.

2. The multi-parameter steam supply system according to claim 1, characterized in that: It also includes a multi-parameter steam supply regulating station, which is arranged at the external steam supply end; The multi-parameter steam supply regulating station is used to regulate the steam supply parameters for external steam supply.

3. The multi-parameter steam supply system according to claim 2, characterized in that: It also includes a steam supply shut-off valve and an overpressure protection valve; the steam supply shut-off valve is arranged between the heating reheater and the multi-parameter steam supply regulating station, and the overpressure protection valve is arranged at the outlet end of the heating reheater; The steam supply shut-off valve is used to connect or disconnect the external steam supply end; The overpressure protection valve is used to protect the heating reheater and the pipeline.

4. The multi-parameter steam supply system according to claim 2, characterized in that: It also includes an overflow regulating station, which is arranged at the outlet end of the heat supply reheater, and the overflow regulating station is arranged in parallel with the multi-parameter steam supply regulating station; The overflow regulating station is used to transport excess steam to the intermediate pressure cylinder to perform work, so as to reduce the fluctuation of steam consumption of the steam supply system.

5. The multi-parameter steam supply system according to claim 4, characterized in that: Also includes a second check valve and an emergency discharge valve; The second check valve is arranged at the inlet end of the overflow regulating station; the emergency discharge valve is arranged between the overflow regulating station and the external steam supply end; The second check valve is used to prevent the steam from flowing back from the overflow regulating station; The emergency discharge valve is used to reduce the steam overflowing from the overflow regulating station to prevent the external steam demand from decreasing.

6. The multi-parameter steam supply system according to claim 1, characterized in that: It also includes pressure relief valves, bypass shut-off valves and maintenance shut-off valves; The pressure relief valve is arranged between the heating bypass and the heating reheater; the bypass shut-off valve is arranged at the inlet end of the heating bypass; The inspection shut-off valve is arranged at the outlet end of the heating bypass; The pressure relief valve is used to protect the inlet pipeline of the heating reheater to prevent the pressure regulation of the heating bypass from being out of balance and causing pipeline overpressure; The bypass shut-off valve is used to cut off the inlet pipeline of the heating bypass; The inspection shut-off valve is used to cut off the outlet pipeline of the heating bypass so as to inspect the heating bypass.

7. A multi-parameter steam supply method, characterized in that: Applied to the multi-parameter steam supply system according to any one of claims 1 to 6, the multi-parameter steam supply method comprises: Based on the heating request information, the outlet pressure of the heating reheater is obtained; comparing the outlet pressure of the heat supply reheater with the heat supply pressure of the steam supply system; When the outlet pressure of the heating reheater is lower than the heating pressure of the steam supply system, the flow distribution station cooperates with the heating bypass to adjust, and the steam supply mode is switched through the heating mode switching valve, so that the outlet pressure of the heating reheater is higher than the heating pressure of the steam supply system; When the outlet pressure of the heat supply reheater is greater than the heat supply pressure of the steam supply system, the steam supply system is controlled to supply steam to the outside.

8. The multi-parameter steam supply method according to claim 7, characterized in that: When the outlet pressure of the heating reheater is lower than the heating pressure of the steam supply system, the flow distribution station cooperates with the heating bypass to adjust, and the steam supply mode is switched by the heating mode switching valve, so that the outlet pressure of the heating reheater is higher than the heating pressure of the steam supply system, including: Obtain the exhaust parameters of the high-pressure cylinder, the inlet flow rate of the peak-shaving reheater, and the inlet flow rate of the heating reheater; Based on the exhaust parameters of the high-pressure cylinder, the inlet flow rate of the peak-shaving reheater, and the inlet flow rate of the heating reheater, an outlet setting value of the heating bypass and an inlet flow setting value of the peak-shaving reheater are obtained; Based on the outlet set value of the heat supply bypass and the inlet flow set value of the peaking reheater, stabilize the inlet flow of the flow distribution station and the inlet flow of the heat supply reheater; Based on the inlet flow of the flow distribution station and the inlet flow of the heat reheater, the flow distribution station and the heat bypass are coordinated for adjustment, and the steam supply mode is switched through the heat supply mode switching valve, so that the outlet pressure of the heat reheater is greater than the heat supply pressure of the steam supply system.

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