Wide-load long-transmission steam pipe network system and operation method thereof

Abstract

The invention belongs to the technical field of industrial production, and provides a wide-load long-transmission steam pipe network system and an operation method thereof. A steam turbine generator unit is connected with a main pipe through a rated parameter steam extraction pipe and a high parameter steam extraction pipe which are connected in parallel; a steam source in a rated parameter steam extraction pipe and a steam source in a high parameter steam extraction pipe are mixed to obtain a steam source higher than rated parameters, especially pressure, so that the specific volume of steam is reduced, if the flow speed in a pipe network is kept unchanged, a large pipe diameter is not needed, the pipe diameters of a main pipe and a branch pipe can be reduced, and through pipe diameter optimization, the cost is reduced. Compared with the prior art, construction investment cost of a pipe network is effectively reduced, along with reduction of the pipe diameter, under the same heat preservation condition, the overall heat dissipation area of the pipeline is reduced, heat dissipation of the pipeline is reduced under low load, temperature drop is smaller, the requirement for lower flow load can be met, along with reduction of the pipe diameter, materials used by the pipeline are reduced, and due to reduction of the surface area, cost is reduced. The requirement for heat preservation is lowered, and the temperature of steam received by a user side can be guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial production, and in particular relates to a wide-load long-distance steam pipeline network system and an operation method thereof. Background Art

[0002] With the rapid development of economy, the heat load in various regions has increased rapidly. The demand for steam in industrial production is increasing. The increase in heat load is bound to bring considerable economic benefits to power plants. However, most industrial enterprises are relatively far away from power plants. Under the premise of meeting the steam parameters of heat users, how to reasonably configure the initial parameters, flow rate, heating pipe diameter, pipe insulation thickness and pipe layout of the power plant heating steam, so that the pressure loss and temperature drop of the steam medium are controlled within a reasonable range and the heating distance is increased, is the most concerned and urgent problem for power plants and users.

[0003] Generally, the design of long-distance steam pipeline network is based on the rated parameters of steam supply. The pipe diameter and insulation are designed according to the user's demand parameters and pipeline route to ensure that the terminal parameters meet the standards. The maximum pressure drop occurs under the condition of maximum flow, that is, the rated condition. In order to reduce the flow rate and flow pressure drop, the main pipes and branch pipes of the long-distance steam pipeline network are designed to be thicker than conventional steam pipelines, which increases the construction investment cost. At the same time, when the long-distance pipeline network is under low load, the steam flow rate is too slow due to the low flow rate, and the heat dissipation time of the steam in the pipeline is increased, resulting in the steam temperature received by the user not meeting the demand. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a wide-load long-distance steam pipeline system and an operation method thereof, in which the steam source in the rated parameter extraction pipe and the steam source in the high parameter extraction pipe are mixed to obtain a steam source higher than the rated parameter, especially the pressure, so that the specific volume of the steam becomes smaller. If the flow velocity in the pipeline network is kept unchanged, a larger pipe diameter is not required, and the pipe diameters of the main pipe and the branch pipe can be reduced, thereby effectively reducing the construction investment cost of the pipeline network. Moreover, as the pipe diameter decreases, under the same insulation conditions, the overall heat dissipation area of ​​the pipeline becomes smaller, the heat dissipation of the pipeline becomes less at low load, and the temperature drop is smaller, which can meet a lower flow load. As the pipe diameter decreases, the material used in the pipeline itself is reduced, and because of the reduction in surface area, the insulation requirements are reduced, which can ensure the temperature of the steam received by the user end.

[0005] In order to achieve the above-mentioned purpose, in a first aspect, the present invention provides a wide-load long-distance steam pipeline network system, which adopts the following technical solutions:

[0006] A wide-load long-distance steam transmission pipe network system comprises a steam turbine generator set, a main pipe connected to the steam turbine generator set, a plurality of branch pipes connected to the main pipe, and a plurality of heat users connected to the plurality of branch pipes;

[0007] The steam turbine generator set is connected to the main pipe through a rated parameter steam extraction pipe and a high parameter steam extraction pipe connected in parallel with each other; the steam source in the rated parameter steam extraction pipe and the steam source in the high parameter steam extraction pipe are mixed to obtain a steam source higher than the rated parameter, thereby reducing the specific volume of the steam and thus reducing the pipe diameters of the main pipe and the branch pipe;

[0008] A regulating valve is provided on the rated parameter steam extraction pipe, and the regulating valve is connected to a controller, and the controller is configured to: adjust the steam pressure provided by the high parameter steam extraction pipe theory through an adjustment value; the adjustment value is obtained by adding preset adjustment parameters and normalization factors based on the main pipe length, branch pipe length, main pipe diameter, branch pipe diameter and the number of users with actual heating demand.

[0009] Furthermore, a temperature and pressure reducer is provided on the main pipe at one end close to the steam turbine generator set; a main shut-off valve is provided on the branch pipe; and a bypass pressure regulating valve is provided on the branch pipe at the position of the main shut-off valve in parallel through a pipeline.

[0010] Furthermore, the steam turbine generator set is connected to the main pipe via a high-parameter steam extraction pipe.

[0011] Furthermore, the steam turbine generator set is connected to the main pipe via a rated parameter steam extraction pipe; a steam compressor is provided between the rated parameter steam extraction pipe and the main pipe.

[0012] Furthermore, the steam pressure provided by the high-parameter steam extraction pipe is:

[0013] P 0h =(P'0-P0)+P x ;

[0014]

[0015] Among them, P 0h P'0 is the steam pressure provided by the high-parameter steam extraction pipe; P'0-P0 is the steam pressure provided by the high-parameter steam extraction pipe theory; P'0 is the required theoretical steam pressure; P0 is the rated steam pressure provided by the rated parameter steam extraction pipe; P x is the adjustment value; λ, ψ and τ are the preset adjustment parameters; μ, σ and is the normalization factor; L 主 is the actual main pipe length; L 支 is the actual branch pipe length; L is the preset theoretical pipe length; n is the number of users with actual heating demand; D 主 is the actual main pipe diameter; D 支 is the actual branch pipe diameter; D is the preset theoretical pipe diameter.

[0016] In order to achieve the above-mentioned purpose, in a second aspect, the present invention also provides a method for operating a wide-load long-distance steam pipeline network system, which adopts the following technical solution:

[0017] A method for operating a wide-load, long-distance steam pipeline network system uses the wide-load, long-distance steam pipeline network system as described in the first aspect, including: mixing the steam source in a rated parameter extraction pipe and the steam source in a high parameter extraction pipe to obtain a steam source higher than the rated parameter, thereby reducing the specific volume of the steam.

[0018] Furthermore, when operating at rated conditions, all heat user loads are at their maximum values, the rated parameter steam extraction pipe and the high parameter steam extraction pipe are opened at the same time, regulated by the temperature and pressure reducer, the main shut-off valves of all branches are opened, and the bypass pressure regulating valves are closed;

[0019] When operating at the lowest load condition, all heat user loads are the minimum values ​​that the pipeline network can meet. Only the rated parameter steam extraction pipe is opened, and the pressure is reduced by the temperature and pressure reducer without reducing the temperature. The main shut-off valves of all branches are closed, and the bypass pressure regulating valve is opened and in the state of adjusting the pressure reduction.

[0020] Further, the parameters include pressure and temperature.

[0021] Furthermore, based on the pressure parameters and temperature parameters at the steam source, a steam source with higher parameters is sought from the power plant, and by mixing it with the steam source with rated pressure parameters and rated temperature parameters, new pressure parameters and temperature parameters at the power plant outlet are obtained; the new pressure parameters and temperature parameters at the power plant outlet are higher than the rated pressure parameters and rated temperature parameters.

[0022] Furthermore, at full load, the steam source parameters are adjusted through the desuperheater and pressure reducer to control the pressure drop of steam in the pipe network; at low load, the steam pressure is lowered through the desuperheater and pressure reducer to reduce the temperature drop of the pipe by increasing the steam specific volume.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] In the present invention, the steam turbine generator set is connected to the main pipe through a rated parameter extraction pipe and a high parameter extraction pipe connected in parallel with each other; the steam source in the rated parameter extraction pipe and the steam source in the high parameter extraction pipe are mixed to obtain a steam source higher than the rated parameter, especially the pressure, so that the specific volume of the steam becomes smaller. If the flow rate in the pipe network is kept unchanged, a larger pipe diameter is not required, and the pipe diameters of the main pipe and the branch pipe can be reduced. Through the optimization of the pipe diameter, the construction investment cost of the pipe network is effectively reduced. Moreover, as the pipe diameter is reduced, under the same insulation conditions, the overall heat dissipation area of ​​the pipeline becomes smaller, and the pipe diameter of the pipeline is reduced at low load. There is less heat dissipation and smaller temperature drop, which can meet lower flow loads. As the pipe diameter decreases, the material used in the pipe itself is reduced. Because the surface area is reduced, the requirements for insulation are reduced, which can ensure the temperature of the steam received by the user end. At the same time, when the steam source is mixed through the high-parameter steam extraction pipe and the steam pressure provided by the high-parameter steam extraction pipe is controlled, the main pipe length, branch pipe length, main pipe diameter, branch pipe diameter and the number of users with actual heating needs are taken into consideration, and the overall steam supply pressure is effectively controlled and adjusted. On the basis of meeting user needs, the phenomenon of excessive steam source pressure is avoided.

[0025] In the present invention, the steam source end and the first section of each branch pipe are respectively provided with pressure regulating means such as a temperature reducing device and a bypass pressure regulator. When the flow rate is low, the steam pressure is increased to increase the steam specific volume, thereby increasing the steam flow rate. The total heat dissipation time of steam with a higher flow rate in the pipeline is shorter, which can effectively reduce the temperature drop and further ensure the temperature at the user's receiving point. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0027] Figure 1 This is a schematic diagram of a first solution of the system of Embodiment 1 of the present invention;

[0028] Figure 2 This is a schematic diagram of a second solution of the system of Embodiment 1 of the present invention;

[0029] Figure 3 This is a schematic diagram of a third solution of the system of Embodiment 1 of the present invention;

[0030] Figure 4 It is the conventional algorithm of the system in Embodiment 1 of the present invention;

[0031] Figure 5 The improved algorithm of the system in Embodiment 1 of the present invention;

[0032] Figure 6 This is a specific example of embodiment 1 of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0034] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0035] Wide load: The operating load can vary in a wide range. For long-distance steam pipelines, it generally means that in addition to rated conditions, it can also operate under lower pressure, temperature and flow conditions; wide load, the optional pipeline load range is about 20%-100%.

[0036] Long-distance steam pipeline network: the pipeline network from thermal power plants to all users.

[0037] Rated parameter steam extraction pipe and high parameter steam extraction pipe: Rated parameter steam extraction pipe refers to a steam extraction pipe with rated steam supply parameters; high parameter steam extraction pipe refers to a steam extraction pipe with pressure parameters higher than the pressure in the rated parameter steam extraction pipe.

[0038] Embodiment 1:

[0039] Generally, the design of long-distance steam pipeline network is based on the rated parameters of steam supply, and the pipe diameter and insulation are designed according to the user's demand parameters and pipeline routing to ensure that the terminal parameters meet the standards. While the pressure drop under full load conditions is qualified, the insulation configuration is optimized to allow the minimum operating flow of the pipeline to reach about 30% of the rated flow, and the operating load width is about 30%-100%. Based on this, if Figure 1 As shown, this embodiment provides a wide-load long-distance steam pipeline system. By adding steam source parameters and branch pipe pressure adjustment means, rationally designing and adjusting the operation method, optimizing the design of pipeline diameters, insulation and other measures, the overall investment in the pipeline network can be reduced, and the operating load range of the pipeline network can be increased. The minimum operating flow rate of the pipeline can reach about 20% of the rated flow rate, and the operating load width is about 20%-100%.

[0040] The system specifically includes a steam turbine generator set, a main pipe connected to the steam turbine generator set, a plurality of branch pipes connected to the main pipe, and a plurality of heat users connected to the plurality of branch pipes; the steam turbine generator set is connected to the main pipe through a rated parameter extraction pipe and a high parameter extraction pipe connected in parallel. Specifically, the steam turbine generator set is connected to the main pipe through a rated parameter extraction pipe and a high parameter extraction pipe connected in parallel; the steam source in the rated parameter extraction pipe and the steam source in the high parameter extraction pipe are mixed to obtain a steam source higher than the rated parameter, especially the pressure, so that the specific volume of the steam becomes smaller. If the flow rate in the pipe network is kept unchanged, a larger pipe diameter is not required, and the pipe diameters of the main pipe and the branch pipe can be reduced. Through the optimization of the pipe diameter, the construction investment cost of the pipe network is effectively reduced. Moreover, as the pipe diameter decreases, under the same insulation conditions, the overall heat dissipation area of ​​the pipeline becomes smaller, the heat dissipation of the pipeline becomes less at low load, the temperature drop is smaller, and a lower flow load can be met. As the pipe diameter decreases, the material used in the pipeline itself is reduced, and because the surface area is reduced, the insulation requirements are reduced, and the temperature of the steam received by the user end can be guaranteed. Specific:

[0041] Traditionally, when designing a long-distance steam pipeline network, the steam source design options are: based on the user parameters and the pressure loss and temperature drop of the pipeline network, the steam source parameters are reversed. At the steam source, the extraction steam that best meets the parameters is selected as the steam source, and the steam parameters may need to be fine-tuned with the temperature reduction or pressure reduction device. The steam source is generally a thermal power plant.

[0042] Based on the traditional long-distance steam pipeline system, the design of the system steam source in this embodiment is different. After obtaining the reverse steam source parameters and selecting the best steam source, a higher-pressure steam source parameter is optimized and designed according to the pipeline layout, and an additional high-pressure steam source is added to meet the parameter requirements.

[0043] Take a thermal power plant as an example to configure the equipment:

[0044] like Figure 1 As shown in the first optional scheme, two extraction steam lines are extracted from the steam turbine of the thermal power plant, namely the rated parameter extraction steam and the high parameter extraction steam. After being combined, the parameters are adjusted by the temperature and pressure reducer before supplying steam to the pipeline network. The high parameter in the high parameter extraction steam is relative to the rated parameter.

[0045] like Figure 2 As shown in the second optional scheme, only high-parameter steam extraction can be performed, and steam can be supplied to the pipeline network after the parameters are adjusted by the temperature and pressure reducer. This is less economical than the first scheme.

[0046] like Figure 3 As shown, in the third optional scheme, it is also possible to only extract steam at rated parameters or low parameters, and add a steam compressor, and use the steam compressor to increase pressure and temperature when the parameters need to be increased. This is less economical than the first scheme.

[0047] In other embodiments, the steam source may not be steam extraction from a steam turbine, but may be direct steam supply from a boiler. The steam source plant may not be a thermal power plant, but may be other plants that can generate steam. In short, no matter how it is configured, the core requirement is that the steam source parameters are adjustable. Compared with the conventional design rated parameters, they can be adjusted higher or lower.

[0048] When the steam network is carried out, the steam can be transported through the main pipe, and a branch pipe is branched from the main pipe to connect to the user when passing through each heat user. A bypass is set near the main pipe at each branch, a main shut-off valve is set on the main line, and a bypass shut-off valve is set on the bypass line.

[0049] If there is only one user in the pipe network, there is no branch pipe and the above settings are not required. If the branch is very close to the heat user and the branch pipe is very short, the above settings are not required for the branch.

[0050] Because when the system in this embodiment operates at rated conditions, that is, when the pipeline flow is maximum, the steam source pressure is greater and the steam specific volume is smaller, the diameters of the main pipes and branch pipes of the pipeline network are designed to be smaller, and less insulation material can be used, thereby effectively reducing the construction investment of the pipeline network.

[0051] Specifically, when operating at rated conditions, the load of all heat users is at the maximum value, and the pipeline flow is at the maximum. At this time, the two steam extraction lines of the power plant are opened at the same time, and the power plant's external steam supply parameters are high-pressure steam source parameters through fine-tuning of the temperature and pressure reducer. The main shut-off valves of all branches are opened, and the bypass pressure regulating valves are closed. The steam pressure received by each heat user meets the demand, and the temperature exceeds the demand.

[0052] When operating at the lowest load condition, the load of all heat users is the minimum value that the pipeline network can meet, and the pipeline network flow is the minimum. At this time, the power plant only opens the rated parameter steam extraction, reduces the pressure through the temperature and pressure reducer but does not reduce the temperature, and the power plant's external steam supply parameters are low-pressure rated temperature parameters. The main shut-off valves of all branches are closed, and the bypass pressure regulating valve is opened and in the state of adjusting the pressure reduction. The steam pressure received by each heat user exceeds the demand, and the temperature meets the demand.

[0053] In traditional systems, the main pipes and branch pipes of long-distance steam pipelines are designed to be thicker than conventional steam pipelines in order to reduce the flow rate and thus reduce the flow pressure drop. The maximum pressure drop occurs under the condition of maximum flow, that is, the rated condition. In the system of this embodiment, the steam source pressure is higher and the steam specific volume is smaller when operating under the rated condition. Therefore, the diameters of the main pipes and branch pipes of the pipeline network are designed to be smaller, and less insulation material can be used, thereby effectively reducing the construction investment of the pipeline network.

[0054] Increase the load width, that is, the flow rate can be lower at low load: Generally, when the long-distance pipeline network is under low load, the steam flow rate is too slow due to the low flow rate, and the heat dissipation time of the steam in the pipeline is increased. The temperature of the steam received by the user may not meet the demand. Based on this, the system in this embodiment has pressure regulating means at the steam source end and the first section of each branch of the long-distance steam pipeline network. When the flow rate is low, the steam flow rate can be increased by increasing the steam pressure and the steam specific volume. The total heat dissipation time of steam with a higher flow rate in the pipeline is shorter, so the temperature drop can be effectively reduced to ensure the temperature at the user's receiving point.

[0055] In conventional system algorithms, such as Figure 4 As shown in the figure, a planned industrial steam heating network. The steam parameters (pressure P, temperature T) of each heat user are: P1, T1, P2, T2, P3, T3, and the steam load (mass flow) is Q1, Q2 and Q3 respectively. It is planned to supply steam from a thermal power plant. According to the conventional scheme, the design is expected to achieve the industry advanced indicators of pressure drop ΔP and temperature drop ΔT per kilometer. Therefore, the pressure, temperature and flow parameters of the upstream diversion nodes of each user can be calculated in combination with the pipeline network routing, such as Figure 4 The cases are: a , T a , Q a , P b , T b , Q b . And finally the steam source parameters P0, T0, Q0 are calculated.

[0056] Therefore, the steam state of each main line and branch line has been preliminarily determined. The pressure drop is the largest at the rated flow (maximum flow). By calculating the pressure drop state at the rated flow, the diameter of each main pipe and branch pipe is determined. Given the pipe diameter and insulation material selection, the insulation thickness can also be calculated to ensure the target temperature drop. Then calculate the low-load temperature drop and the minimum steam supply capacity of the pipe network.

[0057] Inside the power plant, a suitable steam source is designed based on the steam source parameters P0, T0 and Q0 to meet the parameter requirements for external steam supply.

[0058] Therefore, based on the system in this embodiment, a wide load long-distance steam pipeline network system design algorithm is also provided, such as Figure 5 As shown in the figure, a planned industrial steam heating network. The steam parameters (pressure and temperature) of each heat user are: P1, T1, P2, T2, P3 and T3, and the steam load (mass flow) is Q1, Q2 and Q3. It is planned to supply steam from a thermal power plant. According to the conventional scheme, the design is expected to achieve the industry advanced indicators of pressure drop ΔP and temperature drop ΔT per kilometer. Therefore, the pressure, temperature and flow parameters of the upstream diversion nodes of each user can be calculated in combination with the pipeline network routing, such as Figure 5 The middle cases are: P a , Ta , Q a , P b , T b and Q b Finally, the steam outlet pressure P0, steam outlet temperature T0 and steam outlet load Q0 parameters at the steam source are calculated.

[0059] According to the traditional algorithm, the diameter and insulation thickness of each main pipe and branch pipe of a group of pipe networks can be verified based on the above data, and then the optimization algorithm in this embodiment is used for optimization. First, the pipe diameter is optimized. According to P0 and T0, a steam source with higher parameters P is found from the power plant. 0h and T 0h , by mixing with the steam source of rated parameters (P0, T0), the new steam source parameters P'0 and T'0 at the power plant outlet can be obtained. The new steam parameters are higher than the original rated parameters, especially the pressure, which makes the specific volume of the steam smaller. If the flow rate in the pipeline network remains unchanged, the pipe diameter does not need to be as large as before, so the pipe diameter can be thinner. There are two principles for the selection of high-parameter steam sources: one is that the parameters are high enough and the flow rate is large enough to ensure the new steam with parameters P'0 and T'0 at the modulation point; the second is to make the pipe diameter thin enough, at least reduce it by one level, to truly achieve the effect of pipe diameter optimization.

[0060] In some embodiments, the steam pressure provided by the high parameter extraction pipe is:

[0061] P 0h =(P'0-P0)+P x ;

[0062]

[0063] Among them, P 0h The steam pressure provided for the high-parameter steam extraction pipe can be controlled by controlling the opening of the regulating valve on the high-parameter steam extraction pipe. The regulating valve is connected to a controller, 0≤P 0h ≤P 0hmax , P 0hmax is the maximum steam pressure that the high-parameter steam extraction pipe can provide; P'0 is the required theoretical steam pressure; P0 is the rated steam pressure provided by the rated parameter steam extraction pipe; P x is the adjustment value; λ, ψ and τ are preset adjustment parameters, which can be obtained according to experiments; when L 主 / L+L 支 When / L is greater than 1, λ is a positive number, otherwise, λ is a negative number; when D 主 / D+D 支 When / D is greater than 1, τ is positive, otherwise, τ is negative; μ, σ and The normalization factor can convert the three values ​​before and after the "+" into the value of the uniform unit of gas pressure; L 主is the actual main pipe length, which can be obtained by measurement or other testing methods; L 支 is the actual branch pipe length, which can be obtained through measurement or other detection methods; L is the preset theoretical pipe length, which can be obtained through design drawings, etc.; n is the number of users with actual heating demand; D 主 is the actual main pipe diameter, which can be obtained by measurement or other testing methods; D 支 is the actual branch pipe diameter, which can be obtained through measurement or other detection methods; D is the preset theoretical pipe diameter, which can be obtained through design drawings, etc., such as taking the largest diameter value among all designed pipes.

[0064] In this embodiment, when the steam source is mixed through the high-parameter steam extraction pipe and the steam pressure provided by the high-parameter steam extraction pipe is controlled, the main pipe length, branch pipe length, main pipe diameter, branch pipe diameter and the number of users with actual heating needs are taken into consideration, and the overall steam supply pressure is effectively controlled and adjusted. On the basis of meeting user needs, the phenomenon of excessive steam source pressure causing damage to the pipeline and instruments on the pipeline is avoided.

[0065] In this embodiment, all parameter detections can be achieved through corresponding sensors, and the control of flow rate, etc. can be achieved by controlling related regulating valves, etc. through a controller. The controller connects all sensors and control objects, and the controller has data processing functions, which will not be described in detail here.

[0066] As the pipe diameter decreases, under the same insulation conditions, the overall heat dissipation area of ​​the pipeline becomes smaller. At low loads, the heat dissipation of the pipeline becomes less, and the temperature drop is smaller, so a lower flow load can be met. As the pipe diameter decreases, the material used in the pipeline itself is reduced. Because the surface area is reduced, by calculating the overall heat dissipation of the pipeline network and optimizing the insulation, the amount of insulation material required to achieve the same insulation conditions will also be reduced. The functions of the temperature reducer and pressure reducer are: adjusting the appropriate steam source parameters at full load to control the pressure drop of steam in the pipeline network; at low loads, the steam pressure can be appropriately lowered to further reduce the temperature drop of the pipeline by increasing the steam specific volume. The main valve and pressure regulating valve installed on the branch pipe can work together to play a similar role to the temperature reducer and pressure reducer, but only act on the branch pipe where it is located.

[0067] In summary, by using the system, equipment configuration and operation method in the embodiments, it is possible to achieve the effect of reducing project investment and increasing the low-load operation width.

[0068] Based on the system and design algorithm in this embodiment, a specific example is also provided. When optimizing a complex pipe network, it is necessary to comprehensively consider the parameters, loads, and routing characteristics of each branch, and the design optimization process is extremely complicated. Considering the use of the system design, equipment configuration, and operation method of this embodiment, the transformation and upgrading of the industrial steam pipe network is holistic, that is, it is effective for both the main road and the branch road, and the working principle is the same. A relatively simplified example is given here to illustrate the effect principle of this patent.

[0069] like Figure 6 As shown in the figure, an industrial steam heating network. When the end users of the network are relatively concentrated and the main route is long, the overall project investment amount and network operation characteristics of the network are largely related to the design of the main pipe, while the influence of the branch pipe is relatively small. At this time, the parameter characteristics from the main route to the terminal branch a basically represent the overall characteristics of the network.

[0070] Optionally, a is the entrance to the industrial park, and the user requires the following parameters: 1.3MPa.g, 220℃, 300t / h; the main road is 22km long and is arranged overhead; the pipeline requires full load, the pressure drop is not higher than 0.03MPa / km, the temperature drop meets the user's needs, and the steam should be superheated; according to the requirements, the steam source parameters are designed to be 1.9MPa.g and 330℃, and the calculation and optimization are carried out to design the pipeline as Φ914x12.7 carbon steel pipeline, and the insulation is 300mm thick high-temperature glass wool; at full load, the pressure at a is 1.49MPa.g and the temperature is 283℃. The minimum load is 90t / h, the pressure at a is 1.96MPa.g, and the temperature is 225℃. The load range of the pipeline network is 30%-100%.

[0071] After optimization, the optional parameter characteristics of the main pipeline to the terminal branch a are: the user's required parameters are: 1.3MPa.g, 220℃, 300t / h; the main pipeline is 22km long and is arranged overhead; the pipeline requires full load, the pressure drop and temperature drop meet the user's needs, and the steam should be superheated; 4) Matching high-parameter steam source: 1.9MPa.g, 350℃; after calculation and optimization based on the new parameters, the designed pipeline is Φ762x16 carbon steel pipeline, and the insulation is 300mm thick high-temperature glass wool; at full load, the pressure at a is 1.99MPa.g and the temperature is 301℃. No temperature reducer is used to reduce the parameters, the minimum load is 70t / h, the pressure at a is 1.93MPa.g, and the temperature is 225℃. The load range of the pipeline network is 23%-100%. Use the temperature reducer to reduce the steam source parameters to 1.5MPa.g and 350℃. The lowest load can be reduced to 50t / h, the pressure at point a is 1.93MPa.g, and the temperature is 224℃. The load range of the pipeline network is 17%-100%.

[0072] In summary, after adopting the system and operation method in this embodiment, the pipe diameter is optimized from Φ914x12.7 to Φ762x16, which is equivalent to a 2% saving in engineering workload, and the load width is increased from 30%-100% to 17%-100%, an increase of 13%.

[0073] Embodiment 2:

[0074] The present embodiment provides a method for operating a wide-load, long-distance steam pipeline network system, using the wide-load, long-distance steam pipeline network system as described in Example 1, including: mixing the steam source in the rated parameter extraction pipe and the steam source in the high-parameter extraction pipe to obtain a steam source higher than the rated parameter, thereby reducing the specific volume of the steam.

[0075] Optionally, when operating at rated conditions, all heat user loads are at maximum values, the rated parameter steam extraction pipe and the high parameter steam extraction pipe are opened at the same time, regulated by the temperature and pressure reducer, the main shut-off valves of all branches are opened, and the bypass pressure regulating valve is closed;

[0076] When operating at the lowest load condition, all heat user loads are the minimum values ​​that the pipeline network can meet. Only the rated parameter steam extraction pipe is opened, and the pressure is reduced by the temperature and pressure reducer without reducing the temperature. The main shut-off valves of all branches are closed, and the bypass pressure regulating valve is opened and in the state of adjusting the pressure reduction.

[0077] Optionally, the parameters include pressure and temperature. According to the pressure parameters and temperature parameters at the steam source, a steam source with higher parameters is found from the power plant, and the new pressure parameters and temperature parameters at the outlet of the power plant are obtained by mixing with the steam source with rated pressure parameters and rated temperature parameters; the new pressure parameters and temperature parameters at the outlet of the power plant are higher than the rated pressure parameters and rated temperature parameters. At full load, the appropriate steam source parameters are adjusted through the desuperheater and pressure reducer to control the pressure drop of steam in the pipeline network; at low load, the steam pressure is lowered through the desuperheater and pressure reducer, and the temperature drop of the pipeline is reduced by increasing the specific volume of steam.

[0078] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A wide load long distance steam pipeline network system, characterized in that: It comprises a steam turbine generator set, a main pipe connected to the steam turbine generator set, a plurality of branch pipes connected to the main pipe, and a plurality of heat users connected to the plurality of branch pipes; The steam turbine generator set is connected to the main pipe via a rated parameter steam extraction pipe and a high parameter steam extraction pipe connected in parallel with each other; Mixing the steam source in the rated parameter extraction pipe with the steam source in the high parameter extraction pipe to obtain a steam source higher than the rated parameter, thereby reducing the specific volume of the steam and thus reducing the pipe diameters of the main pipe and the branch pipe; A regulating valve is provided on the rated parameter steam extraction pipe, and the regulating valve is connected to a controller, and the controller is configured to: adjust the steam pressure provided by the high parameter steam extraction pipe theory through an adjustment value; the adjustment value is obtained by adding preset adjustment parameters and normalization factors based on the main pipe length, branch pipe length, main pipe diameter, branch pipe diameter and the number of users with actual heating demand.

2. A wide-load long-distance steam pipeline network system as claimed in claim 1, characterized in that: A temperature and pressure reducer is arranged on the main pipe at one end close to the steam turbine generator set; a main shut-off valve is arranged on the branch pipe; and a bypass pressure regulating valve is arranged on the branch pipe in parallel at the position of the main shut-off valve through a pipeline.

3. A wide-load long-distance steam pipeline network system as claimed in claim 1, characterized in that: The steam turbine generator set is connected to the main pipe via a high-parameter steam extraction pipe.

4. A wide-load long-distance steam pipeline network system as claimed in claim 1, characterized in that: The steam turbine generator set is connected to the main pipe via a rated parameter steam extraction pipe; a steam compressor is arranged between the rated parameter steam extraction pipe and the main pipe.

5. A wide-load long-distance steam pipeline network system as claimed in claim 1, characterized in that: The steam pressure provided by the high-parameter steam extraction pipe is: P 0h =(P’0-P0)+P x ; Among them, P 0h P'0 is the steam pressure provided by the high-parameter steam extraction pipe; P'0-P0 is the steam pressure provided by the high-parameter steam extraction pipe theory; P'0 is the required theoretical steam pressure; P0 is the rated steam pressure provided by the rated parameter steam extraction pipe; P x is the adjustment value; λ, ψ and τ are the preset adjustment parameters; μ, σ and is the normalization factor; L 主 is the actual main pipe length; L 支 is the actual branch pipe length; L is the preset theoretical pipe length; n is the number of users with actual heating demand; D 主 is the actual main pipe diameter; D 支 is the actual branch pipe diameter; D is the preset theoretical pipe diameter.

6. A method for operating a wide-load long-distance steam pipeline network system, characterized in that: A wide-load long-distance steam pipeline network system as described in any one of claims 1 to 5 is used, comprising: mixing the steam source in the rated parameter extraction pipe and the steam source in the high parameter extraction pipe to obtain a steam source higher than the rated parameter, thereby reducing the specific volume of the steam.

7. A method for operating a wide-load long-distance steam pipeline network system according to claim 6, characterized in that: When operating at rated conditions, all heat user loads are at their maximum values, the rated parameter steam extraction pipe and the high parameter steam extraction pipe are opened at the same time, and are adjusted through the temperature and pressure reducer, the main shut-off valves of all branches are opened, and the bypass pressure regulating valves are closed; When operating at the lowest load condition, all heat user loads are the minimum values ​​that the pipeline network can meet. Only the rated parameter steam extraction pipe is opened, and the pressure is reduced by the temperature and pressure reducer without reducing the temperature. The main shut-off valves of all branches are closed, and the bypass pressure regulating valve is opened and in the state of adjusting the pressure reduction.

8. A method for operating a wide-load long-distance steam pipeline network system according to claim 6, characterized in that: Parameters include pressure and temperature.

9. A method for operating a wide-load long-distance steam pipeline network system according to claim 6, characterized in that: According to the pressure parameters and temperature parameters at the steam source, a steam source with higher parameters is sought from the power plant, and by mixing it with the steam source with rated pressure parameters and rated temperature parameters, new pressure parameters and temperature parameters at the power plant outlet are obtained; the new pressure parameters and temperature parameters at the power plant outlet are higher than the rated pressure parameters and rated temperature parameters.

10. A method for operating a wide-load long-distance steam pipeline network system according to claim 6, characterized in that: At full load, the steam source parameters are adjusted through the desuperheater and pressure reducer to control the pressure drop of steam in the pipeline network; at low load, the steam pressure is lowered through the desuperheater and pressure reducer to reduce the temperature drop of the pipeline by increasing the steam specific volume.

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