Cement production industrial load participated power grid dispatching method and related products

Abstract

The invention discloses a cement production industrial load participated power grid dispatching method and related products. According to the method, an objective function is constructed by minimizing the power purchase cost of a cement plant within preset time, constraint conditions comprise a material balance constraint, an electric quantity balance constraint, a storage constraint, a yield constraint and a rotary kiln continuous work constraint, and the constraint conditions consider the coupling relation of all links in the cement production process. Therefore, the formed economic dispatching model can improve the dispatching capability of the cement production industrial load on the power grid. Moreover, in the construction process of the economic dispatching model, materials and processes are abstracted into states and tasks respectively by utilizing a state task network method aiming at the cement production process, and a state task network block diagram is drawn to describe the coupling relationship among the processes, so that the accuracy of the model can be ensured.

Description

Technical Field

[0001] The present application relates to the technical field of construction engineering, and in particular to a power grid dispatching method and related products involving cement production industrial loads. Background Art

[0002] At present, grid dispatching mainly considers objects such as residential loads and commercial loads, while ignoring the adjustable potential of industrial loads. Industrial loads have the advantages of large power consumption, large number of transferable loads, centralized and easy transformation, and high participation enthusiasm, which meet the needs of load participation in grid dispatching. However, due to the complex operational problems in some aspects of current industrial loads, excessive load regulation may occur, which will have a great impact on the normal production of enterprises, resulting in limited willingness of industrial enterprises to participate. Therefore, how to further explore the flexible adjustment resources of industrial loads without affecting the normal production of enterprises as much as possible is an important issue that needs to be solved at present.

[0003] In the related art, the grid dispatching for the cement production industrial load ignores the fact that each process in the cement production process must be carried out in sequence according to a fixed production order, thereby reducing the dispatching capacity of the cement production industrial load on the grid. Summary of the invention

[0004] In view of this, the present application provides a grid dispatching method and related products involving cement production industrial loads, which can improve the dispatching capacity of the cement production industrial load on the grid.

[0005] In a first aspect, the present application provides a method for dispatching a power grid in which a cement production industrial load participates, comprising: An objective function is constructed based on minimizing the electricity purchase cost of the cement plant within a preset time, wherein the objective function uses the operating status of each electrical equipment within the preset time as a decision variable; Constraints are constructed for the objective function, and the constraints include material balance constraints, power balance constraints, storage constraints, output constraints, and rotary kiln continuous operation constraints, so as to determine the grid dispatching result based on the objective function under the constraints.

[0006] Optionally, the objective function is expressed in the following formula: ; In the above formula, The electricity purchase cost for the cement plant during the preset time period, The time period stipulated by the local regulations for enterprises The corresponding time-of-use electricity price is For enterprises in the period of electricity consumption, is the total number of scheduling periods included in the preset time. It is the scheduling step length within the preset time period.

[0007] Optionally, the material balance constraint is expressed in the following formula: ; In the above formula, Indicates state of things In the period Available quantity, Indicates state of things In the period Available quantity, Representation Task Single core device in time period Generate or consume status items The number of Representation Task In the period The total number of core devices in working state, The total number of scheduling periods included in the preset time.

[0008] Optionally, the power balance constraint is expressed in the following formula: ; In the above formula, Indicates that the cement plant is in the period The power consumption, Representation Task Single core device in time period The power consumption, Representation Task In the period The total number of core devices in working state, The total number of scheduling periods included in the preset time.

[0009] Optionally, the storage constraint is expressed in the following formula: ; In the above formula, Indicates state of things The storage limit, Indicates state of things The storage limit of The production constraint is expressed in the following formula: ; In the above formula, Indicates the total number of scheduling periods for the final product cement within the preset time The number at the end, represents the initial quantity of the final product cement at the beginning of the scheduling period, Indicates the cement production requirement within the preset time.

[0010] Optionally, the rotary kiln continuous operation constraint is expressed in the following formula: ; In the above formula, The rotary kiln system, the core electrical equipment for clinker burning, is The operating status of The total number of scheduling periods included in the preset time.

[0011] Optionally, the decision variable corresponding to the objective function is expressed in the following formula: ; In the above formula, Indicates the task No. Core power-consuming equipment in the period The operating status of Indicates the raw material crushing process Core power-consuming equipment in the period The operating status of Indicates the raw material grinding process Core power-consuming equipment in the period The operating status of Indicates the raw material homogenization process Core power-consuming equipment in the period The operating status of Indicates the fuel grinding process Core power-consuming equipment in the period The operating status of Indicates the first step of the clinker burning process Core power-consuming equipment in the period The operating status of Indicates the cement grinding process Core power-consuming equipment in the period The running status of

[0012] In a second aspect, the present application provides a power grid dispatching device in which cement production industrial loads participate, comprising: The first construction module is used to construct an objective function based on minimizing the electricity purchase cost of the cement plant within a preset time, wherein the objective function uses the operating status of each electrical equipment within the preset time as a decision variable; The second construction module is used to construct constraint conditions for the objective function, wherein the constraint conditions include material balance constraint, power balance constraint, storage constraint, output constraint and rotary kiln continuous operation constraint, so as to determine the power grid dispatching result based on the objective function under the constraint conditions.

[0013] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the above method when the computer program is executed by a processor.

[0014] In a fourth aspect, the present application provides an execution device, comprising a processor and a memory, wherein the processor is coupled to the memory; The memory is used to store programs; The processor is used to execute the program in the memory, so that the execution device executes the above method.

[0015] In the method disclosed in the present application, the objective function is constructed by minimizing the electricity purchase cost of the cement plant within a preset time. The constraints include material balance constraints, electricity balance constraints, storage constraints, output constraints and rotary kiln continuous operation constraints. These constraints take into account the coupling relationship between various links in the cement production process. The economic scheduling model thus formed can improve the scheduling capacity of the cement production industrial load on the power grid.

[0016] At the same time, in the process of constructing this economic scheduling model, the state-task network method is used to abstract materials and processes into states and tasks respectively for the cement production process, and a state-task network diagram is drawn to characterize the coupling relationship between the processes, which can ensure the accuracy of the economic scheduling model. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0018] Figure 1 An operational flow chart of a method for dispatching a power grid in which cement production industrial loads participate is shown according to an exemplary embodiment.

[0019] Figure 2 A cement production flow chart is shown according to an exemplary embodiment.

[0020] Figure 3 A block diagram of a state task network for cement production provided by an exemplary embodiment is shown.

[0021] Figure 4 A block diagram of a power grid dispatching device in which cement production industrial loads participate is shown according to an exemplary embodiment.

[0022] Figure 5 A block diagram of the execution device provided by an exemplary embodiment is shown. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below. The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described here can be implemented in an order other than that illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules that are not clearly listed or inherent to these processes, methods, products or devices. The naming or numbering of steps in this application does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The process steps that have been named or numbered can change the execution order according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved. The division of units in this application is a logical division. There may be other division methods when it is implemented in actual applications. For example, multiple units can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection between units can be electrical or other similar forms, which are not limited in this application. In addition, the units or sub-units described as separate components may or may not be physically separated, may or may not be physical units, or may be distributed in multiple circuit units, and some or all of the units may be selected according to actual needs to achieve the purpose of the present application.

[0024] The "cement production industrial load" mentioned in this text refers to the electricity load generated during the cement production process.

[0025] Please refer to Figure 2 Now, the relevant process analysis of cement production process is elaborated in detail. The new dry process cement production technology is adopted, which mainly includes six processes such as raw material crushing, raw material grinding, raw material homogenization, fuel grinding, clinker burning and cement grinding. Storage facilities are set between each process, making the load adjustment of cement plant more flexible.

[0026] (1) Raw material crushing (RMC) The raw material crushing process crushes raw materials such as limestone, clay, and iron ore. The crushed raw materials are stored and pre-homogenized in the pre-homogenization yard according to scientific stacking and reclaiming technology. Considering the power consumption of each equipment, the core power-consuming equipment used in this process is the crusher, and the materials consumed are various raw materials for cement production, including limestone, iron ore, etc. The generated materials are small-particle raw materials after crushing.

[0027] (2) Raw meal grinding (RMG) The raw material grinding process grinds the small-particle raw materials after drying until the raw material fine powder with appropriate particle size is obtained. The ground raw materials are stored in the raw material reserve. Considering the power consumption of each equipment, the core power-consuming equipment used in this process is the raw material grinding machine, which consumes small-particle raw materials and produces raw material fine powder.

[0028] (3) Raw meal homogenizing (RMH) The raw material homogenization process homogenizes the fine raw material powder after grinding to make the raw material mixed evenly and maintain a stable state. The raw material homogenization warehouse realizes the integrated functions of stirring, homogenization and kiln material storage. Considering the power consumption of each equipment, the core power-consuming equipment used in this process is the raw material homogenization warehouse, the material consumed is the raw material powder, and the material generated is the raw material entering the kiln (i.e. kiln material).

[0029] (4) Fuel powder polishing (FPP) The fuel grinding process grinds the crushed coal blocks to obtain coal powder, which is then used in the clinker burning process. Considering the power consumption of each device, the core power-consuming equipment used in this process is the coal mill, which consumes small-particle coal blocks and produces coal powder.

[0030] (5) Clinker firing (CF) The clinker burning process preheats and decomposes the raw materials entering the kiln and burns the clinker. The generated clinker is stored in the clinker warehouse after cooling. Considering the power consumption of each equipment, the core power-consuming equipment used in this process is the rotary kiln. Since the core power-consuming equipment rotary kiln system needs to work continuously under normal circumstances and cannot be shut down or transfer load, the clinker burning task is a non-schedulable task. The materials consumed are the raw materials entering the kiln and coal powder, and the generated materials are clinker.

[0031] (6) Cement grinding (CG) The cement grinding process grinds clinker, limestone, gypsum, etc. to obtain cement fine powder with appropriate particle size and stores it in the cement finished product warehouse. Considering the power consumption of each equipment, the core power-consuming equipment used in this process is the cement grinding machine, the materials consumed are clinker, limestone, gypsum, etc., and the generated material is the cement fine powder finished product.

[0032] Please refer to Figure 3 For the above-mentioned cement production process, the state-task network method can be adopted, that is, the materials required for cement production are abstracted as states, and the various processes included in the cement production process are abstracted as tasks, and the interactive relationship between tasks and materials is reflected, so as to construct constraint conditions that reflect objective functions such as material quantity, production tasks, and equipment operation requirements.

[0033] like Figure 3 The state task network (STN) diagram shown in the figure contains two types of nodes, task nodes and state nodes, where task nodes represent processing operations, including schedulable tasks and unschedulable tasks; state nodes represent different states of materials, namely raw materials, intermediate products and final products; the two are connected by connecting arcs to represent the interactive relationship between tasks and states. That is, the state task network diagram abstracts the process and materials into tasks and states respectively, and describes the flow of materials.

[0034] The raw material crushing task consumes raw materials such as limestone to generate intermediate small-particle raw materials; the raw material grinding task consumes intermediate small-particle raw materials to generate intermediate raw material fine powder; the raw material homogenization task consumes intermediate raw material fine powder to generate intermediate kiln material; the fuel grinding task consumes raw material small-particle coal blocks to generate intermediate coal powder; the unschedulable task clinker burning task consumes intermediate kiln material and coal powder to generate intermediate clinker; the cement grinding task consumes intermediate clinker to generate the final product cement. Since gypsum and other mixed materials involve fewer processes and sufficient reserves, their participation is not considered in the cement grinding task, but for the sake of process integrity, they are still represented in the state task network diagram.

[0035] Please refer to Figure 1 ,in Figure 1 A flowchart of a method for dispatching a power grid in which cement production industrial loads participate is shown in accordance with an exemplary embodiment. The method is implemented through steps 102-104.

[0036] In step 102, an objective function is constructed based on minimizing the electricity purchase cost of the cement plant within a preset time, and the objective function uses the operating status of each electrical equipment within the preset time as a decision variable.

[0037] Here, the preset time is generally demonstrated as one day, but of course you can also choose one week or one month as needed.

[0038] As an exemplary specific example, the objective function is expressed in the following formula: (1) In the above formula (1), The electricity purchase cost for the cement plant during the preset time period, The time period stipulated by the local regulations for enterprises The corresponding time-of-use electricity price is For enterprises in the period of electricity consumption, is the total number of scheduling periods included in the preset time. It is the scheduling step length within the preset time period.

[0039] As an exemplary specific example, the decision variable corresponding to the objective function is expressed in the following formula: (2) In the above formula (2), Indicates the task No. Core power-consuming equipment in the period The operating status of Indicates the raw material crushing process Core power-consuming equipment in the period The operating status of Indicates the raw material grinding process Core power-consuming equipment in the period The operating status of Indicates the raw material homogenization process Core power-consuming equipment in the period The operating status of Indicates the fuel grinding process Core power-consuming equipment in the period The operating status of Indicates the first step of the clinker burning process Core power-consuming equipment in the period The operating status of Indicates the cement grinding process Core power-consuming equipment in the period The running status of

[0040] That is, in this specific example, the decision variables represent the operating status of the overall equipment of each process according to the operating status of the core power-consuming equipment in each process of cement production. This is because the power consumption of the core power-consuming equipment in each process is much higher than that of the remaining equipment. Therefore, using the core power-consuming equipment of each process instead of the overall equipment to represent it can reduce the complexity of the model.

[0041] It should be noted that , , , , , The value is 0 or 1, where 0 indicates shutdown status and 1 indicates working status.

[0042] In step 104, constraints are constructed for the objective function, wherein the constraints include material balance constraints, power balance constraints, storage constraints, output constraints, and rotary kiln continuous operation constraints, so as to determine the grid dispatch result based on the objective function under the constraints.

[0043] As an exemplary specific example, the material balance constraint is expressed in the following formula: (3) In the above formula (3), Indicates state of things In the period Available quantity, Indicates state of things In the period Available quantity, Indicates the task Single core device in time period Generate or consume status items The number of Indicates the task In the period The total number of core devices in working state, The total number of scheduling periods included in the preset time.

[0044] As an exemplary specific example, the power balance constraint is expressed in the following formula: (4) In the above formula (4), Indicates that the cement plant is in the period The power consumption, Indicates the task Single core device in time period The power consumption, Indicates the task In the period The total number of core devices in working state, The total number of scheduling periods included in the preset time.

[0045] As an exemplary specific example, the storage constraint is expressed in the following formula: (5) In the above formula (5), Indicates state of things The storage limit, Indicates state of things The storage limit.

[0046] As an exemplary specific example, the production constraint condition is expressed in the following formula: (6) In the above formula (6), Indicates the total number of scheduling periods for the final product cement within the preset time The number at the end, represents the initial quantity of the final product cement at the beginning of the scheduling period, Indicates the cement production requirement within the preset time.

[0047] Since the rotary kiln system must operate continuously under normal circumstances, except for occasional inventory control shutdowns when cement demand is low, there are only one or two shutdowns per year for planned maintenance. As an exemplary specific example, the rotary kiln continuous operation constraint is expressed in the following formula: (7) In the above formula (7), The rotary kiln system, the core electrical equipment for clinker burning, is Here, 1 means the rotary kiln is in the period In working condition, 0 means the rotary kiln is in the period In shutdown state, The total number of scheduling periods included in the preset time.

[0048] It is easy for technicians in the relevant field to think of that the grid dispatching result is determined based on the objective function under the constraints. It can be based on a known source-load model or source-load-storage model (including but not limited to CN113452052A, CN115860274A and other technologies), and the adjustable value such as the capacity of the cement production industrial load can be determined according to the decision variables corresponding to the optimal solution of the objective function. The adjustable value is the grid dispatching result.

[0049] Please refer to Figure 4 , which shows a block diagram of the power grid dispatching device for cement production industrial load participation provided by the present application. The device 200 includes: The first construction module 202 is used to construct an objective function based on minimizing the electricity purchase cost of the cement plant within a preset time, wherein the objective function uses the operating status of each electrical equipment within the preset time as a decision variable; The second construction module 204 is used to construct constraint conditions for the objective function, wherein the constraint conditions include material balance constraint, power balance constraint, storage constraint, output constraint and rotary kiln continuous operation constraint, so as to determine the grid dispatch result based on the objective function under the constraint conditions.

[0050] Since the above methods have been discussed in detail, the specific implementation of the above modules will not be repeated here.

[0051] Next, an execution device provided by an embodiment of the present application is introduced. Figure 5 , Figure 5 This is a schematic diagram of a structure of an execution device provided in an embodiment of the present application. The execution device 300 can be specifically manifested as an autonomous driving vehicle, a mobile phone, a tablet, a laptop computer, a desktop computer, a monitoring data processing device, etc., which is not limited here. Figure 1 The functions of the execution device in the corresponding embodiment. Specifically, the execution device 300 includes: a receiver 301, a transmitter 302, a processor 303 and a memory 304 (wherein the number of the processor 303 in the execution device 300 can be one or more, Figure 5 In the example of FIG. 3 , the processor 303 may include an application processor 3031 and a communication processor 3032. In some embodiments of the present application, the receiver 301, the transmitter 302, the processor 303 and the memory 304 may be connected via a bus or other means.

[0052] The memory 304 may include a read-only memory and a random access memory, and provides instructions and data to the processor 303. A portion of the memory 304 may also include a non-volatile random access memory (NVRAM). The memory 304 stores processor and operation instructions, executable modules or data structures, or subsets thereof, or extended sets thereof, wherein the operation instructions may include various operation instructions for implementing various operations.

[0053] The processor 303 controls the operation of the execution device. In a specific application, the various components of the execution device are coupled together through a bus system, wherein the bus system includes not only a data bus but also a power bus, a control bus, and a status signal bus, etc. However, for the sake of clarity, various buses are referred to as bus systems in the figure.

[0054] The method disclosed in the above embodiment of the present application can be applied to the processor 303, or implemented by the processor 303. The processor 303 can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 303. The above processor 303 can be a general processor, a digital signal processor (digital signal processing, DSP), a microprocessor or a microcontroller, and can further include an application specific integrated circuit (application specific integrated circuit, ASIC), a field programmable gate array (field-programmable gate array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The processor 303 can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to execute, or it can be executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 304, and the processor 303 reads the information in the memory 304 and completes the steps of the above method in combination with its hardware.

[0055] The receiver 301 can be used to receive input digital or character information and generate signal input related to the relevant settings and function control of the execution device. The transmitter 302 can be used to output digital or character information through the first interface; the transmitter 302 can also be used to send instructions to the disk group through the first interface to modify the data in the disk group; the transmitter 302 can also include a display device such as a display screen.

[0056] In the embodiment of the present application, the processor 303 is used to execute Figure 1 The specific manner in which the application processor 3031 in the processor 303 performs the above steps is the same as that in the present application. Figure 1 The corresponding method embodiments are based on the same concept, and the technical effects they bring are the same as those in this application. Figure 1 The corresponding method embodiments are the same. For specific contents, please refer to the description in the method embodiments shown above in this application, which will not be repeated here.

[0057] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A method for dispatching a power grid in which cement production industrial loads participate, characterized in that: include: An objective function is constructed based on minimizing the electricity purchase cost of the cement plant within a preset time, wherein the objective function uses the operating status of each electrical equipment within the preset time as a decision variable; Constraints are constructed for the objective function, and the constraints include material balance constraints, power balance constraints, storage constraints, output constraints, and rotary kiln continuous operation constraints, so as to determine the grid dispatching result based on the objective function under the constraints.

2. The method according to claim 1, characterized in that The objective function is expressed in the following formula: ； In the above formula, The electricity purchase cost for the cement plant during the preset time period, The time period stipulated by the local regulations for enterprises The corresponding time-of-use electricity price is For enterprises in the period of electricity consumption, is the total number of scheduling periods included in the preset time. It is the scheduling step length within the preset time period.

3. The method according to claim 1, characterized in that The material balance constraint is expressed in the following formula: ； In the above formula, Indicates state of things In the period Available quantity, Indicates state of things In the period Available quantity, Indicates the task Single core device in time period Generate or consume status items The number of Indicates the task In the period The total number of core devices in working state, The total number of scheduling periods included in the preset time.

4. The method according to claim 1, characterized in that The power balance constraint is expressed in the following formula: ； In the above formula, Indicates that the cement plant is in the period The power consumption, Indicates the task Single core device in time period The power consumption, Indicates the task In the period The total number of core devices in working state, The total number of scheduling periods included in the preset time.

5. The method according to claim 1, characterized in that The storage constraint is expressed in the following formula: ； In the above formula, Indicates state of things The storage limit, Indicates state of things The storage limit of The production constraint is expressed in the following formula: ； In the above formula, Indicates the total number of scheduling periods for the final product cement within the preset time The number at the end, represents the initial quantity of the final product cement at the beginning of the scheduling period, Indicates the cement production requirement within the preset time.

6. The method according to claim 1, characterized in that The continuous operation constraint of the rotary kiln is expressed in the following formula: ； In the above formula, The rotary kiln system, the core electrical equipment for clinker burning, is The operating status of The total number of scheduling periods included in the preset time.

7. The method according to claim 1, characterized in that The decision variables corresponding to the objective function are expressed in the following formula: ； In the above formula, Indicates the task No. Core power-consuming equipment in the period The operating status of Indicates the raw material crushing process Core power-consuming equipment in the period The operating status of Indicates the raw material grinding process Core power-consuming equipment in the period The operating status of Indicates the raw material homogenization process Core power-consuming equipment in the period The operating status of Indicates the fuel grinding process Core power-consuming equipment in the period The operating status of Indicates the first step of the clinker burning process Core power-consuming equipment in the period The operating status of Indicates the cement grinding process Core power-consuming equipment in the period The running status of 8. A power grid dispatching device for cement production industrial load participation, characterized in that: include: The first construction module is used to construct an objective function based on minimizing the electricity purchase cost of the cement plant within a preset time, wherein the objective function uses the operating status of each electrical equipment within the preset time as a decision variable; The second construction module is used to construct constraint conditions for the objective function, wherein the constraint conditions include material balance constraint, power balance constraint, storage constraint, output constraint and rotary kiln continuous operation constraint, so as to determine the power grid dispatching result based on the objective function under the constraint conditions.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. An execution device, characterized in that: comprising a processor and a memory, wherein the processor is coupled to the memory; The memory is used to store programs; The processor is configured to execute the program in the memory so that the execution device executes the method according to any one of claims 1 to 7.

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