阅读说明：本技术 风电叶片模具、叶片模具制备方法及模具型面监测系统 (Wind power blade mold, blade mold manufacturing method and mold profile monitoring system ) 是由 黄尚洪 张雷达 李义全 贾玉玺 陈忠丽 刘晓彬 陈万康 于 2020-06-19 设计创作，主要内容包括：本发明提供一种智能风电叶片模具、叶片模具制备方法及模具型面监测系统；其中,智能风电叶片模具包括上模和下模；上模的结构包括：内结构层、加热层和外结构层；下模的结构与上模相同；加热层包括：导热凝脂层、铜管或加热丝,以及光纤光栅；内结构层为采用树脂在表面毡、无碱布和多轴向多层织物通过真空灌注工艺形成的固化结构层；所述方法包括如下步骤：制备叶片模具内结构层；制备加热层；制备外结构层。模具型面监测系统,包括：风电叶片模具和光纤光栅解调仪；光纤光栅解调仪通过光纤与风电叶片模具的光纤光栅信号连接；本发明解决了如何精确监测模具内部应变和温度变化的相关技术问题。(The invention provides an intelligent wind power blade mould, a blade mould preparation method and a mould profile monitoring system; the intelligent wind power blade mould comprises an upper mould and a lower mould; the structure of last mould includes: an inner structural layer, a heating layer and an outer structural layer; the structure of the lower die is the same as that of the upper die; the heating layer includes: a heat conducting grease layer, a copper pipe or a heating wire, and a fiber grating; the inner structure layer is a solidified structure layer formed by resin on a surface felt, alkali-free cloth and multi-axial multi-layer fabric through a vacuum infusion process; the method comprises the following steps: preparing an inner structure layer of the blade mould; preparing a heating layer; and preparing an outer structure layer. A mold profile monitoring system comprising: the wind power blade mold and the fiber bragg grating demodulator are arranged on the wind power blade mold; the fiber grating demodulator is in signal connection with the fiber grating of the wind power blade mould through an optical fiber; the invention solves the related technical problem of how to accurately monitor the internal strain and temperature change of the die.)

1. A wind turbine blade mold, comprising: an upper die and a lower die;

the structure of last mould includes: an inner structural layer, a heating layer and an outer structural layer; the shape of the upper die is matched with the shape of the upper surface of the wind power blade; the structure of the lower die is the same as that of the upper die; the shape of the lower die is matched with the shape of the lower surface of the wind power blade; the upper die and the lower die are aligned and buckled;

the heating layer includes: the thermal grease is composed of a thermal grease layer formed by pouring and solidifying after mixing resin and a heat transfer medium, a copper pipe or a heating wire solidified in the grease layer, and a fiber grating; the fiber grating is arranged in the arrangement gap of the copper pipe or the heating wire;

a surface felt, an alkali-free cloth and a multi-axial multilayer fabric are arranged in the inner structure layer in a stacking mode; the connection mode between two adjacent surface felts is lap joint; the connection mode between two adjacent alkali-free cloths is lap joint; the connection mode between two adjacent multiaxial multilayer fabrics is lap joint; the inner structure layer is a solidified structure layer formed by pouring resin on the surface felt, the alkali-free cloth and the multi-axial multilayer fabric;

the outer structure layer is internally provided with a multi-axial multilayer fabric, balsawood and a multi-axial multilayer fabric in a sequential stacking manner; wherein, the connection mode of two adjacent multiaxial multilayer fabrics is lap joint; the connection mode of two adjacent balsawood is splicing; the outer structure layer is a solidified structure layer formed by adopting resin to solidify after vacuum-assisted infusion on the multi-axial multilayer fabric, the balsawood and the multi-axial multilayer fabric.

2. The wind-power blade mold according to claim 1, wherein the fiber bragg grating is formed by connecting a plurality of FBG bare gratings in series; the plurality of fiber gratings form a fiber Bragg grating in the heating layer, and the fiber gratings in the heating layer are not in contact with each other; in the optical fiber Bragg grating, a plurality of optical fiber gratings are connected to the same user interface together; the user interface is used for connecting the fiber grating demodulator to realize wavelength division multiplexing.

3. The wind blade mold according to claim 2, wherein the fiber grating is shaped as an independent optical fiber; the fiber bragg grating is formed by serially connecting a plurality of FBG bare gratings with different central wavelengths.

4. The wind-power blade mold according to claim 2, wherein a heat-shrinkable tube for packaging protection is arranged at the welding point position where the FBG bare grids are connected in series.

5. The wind power blade mold according to claim 1, wherein an insulating layer is further attached to the outer surface of the outer structural layer; the heat transfer medium is aluminum powder.

6. The wind-power blade mold according to claim 1, wherein the inner structure layer and the outer structure layer are respectively provided with grooves with the shape matched with the fiber bragg grating at the positions corresponding to the fiber bragg grating arrangement positions; the depth of the groove is 0.5mm, and the width of the groove is 1 mm.

7. A method for preparing a blade mould, characterized in that the method comprises the following steps:

step 1: pouring resin on a multilayer structure sequentially formed by stacking a surfacing mat, alkali-free cloth and multi-axial multilayer fabric in sequence by adopting a vacuum auxiliary pouring process to prepare an inner structure layer of the blade mold; when the surface felt layer consists of a plurality of surface felts, the connection mode between two adjacent surface felts is lap joint; when the alkali-free cloth layer consists of a plurality of alkali-free cloths, the connection mode between two adjacent alkali-free cloths is lap joint; when the multi-axial multilayer fabric layer consists of a plurality of multi-axial multilayer fabrics, the connection mode between two adjacent multi-axial multilayer fabrics is lap joint; the manufacturing quantity of the inner structure layers of the blade mould is two, and the shapes of the inner structure layers are respectively matched with the shapes of the upper side and the lower side of the blade so as to obtain finished products of the inner structure layers of the upper mould and the lower mould;

step 2: after the upper die inner structure layer and the lower die inner structure layer are cured, presetting fiber bragg grating arrangement positions on one sides of the upper die inner structure layer and the lower die inner structure layer facing the blades respectively, or forming grooves at the fiber bragg grating arrangement positions;

and step 3: placing the fiber bragg grating at a preset fiber bragg grating setting position, and further laying a copper pipe or an electric heating wire on the same layer;

and 4, step 4: heating and mixing resin and a heat transfer medium, and pouring the mixture on one side of the upper die inner structure layer and one side of the lower die inner structure layer which face the blades respectively to form a heating layer; polishing and flattening the heating layer when the material is fully solidified to obtain a heating layer with uniform thickness;

and 5: laying a multilayer structure consisting of multi-axial multilayer fabric, balsa wood and multi-axial multilayer fabric on one side of the heating layer, which is used for facing the blade, and preparing an outer structure layer;

step 6: and adopting a vacuum auxiliary pouring process to pour resin on a multilayer structure consisting of the multiaxial multilayer fabric, the balsawood and the multiaxial multilayer fabric to form an outer structure layer, and polishing and flattening the outer structure layer after full solidification to obtain a finished blade mould product.

8. The method of claim 6, further comprising:

and 7: and an insulating layer is attached to the outer side of the outer structural layer.

9. A mold profile monitoring system, comprising: the wind power blade mold and the fiber bragg grating demodulator are arranged on the wind power blade mold; the wind power blade mould is the wind power blade mould as defined in any one of claims 1 to 6 or the wind power blade mould manufactured by the method as defined in any one of claims 7 to 8; and the fiber grating demodulator is in signal connection with the fiber grating of the wind power blade mould through optical fibers.

10. The system for monitoring the mold surface according to claim 9, wherein a sealing bag is disposed at the fiber interface between the fiber grating demodulator and the fiber grating.

Technical Field

The invention relates to the technical field of health monitoring of fiber composite materials, in particular to a wind power blade mold, a blade mold preparation method and a mold profile monitoring system.

Background

The wind power blade is one of key core components for converting wind energy into mechanical energy of the wind generating set, and the quality of the blade directly influences the efficiency and the service life of the wind generating set, so that the performance of the whole system is influenced. In addition to the self-gravity, the blade is subjected to various loads such as aerodynamic force and centrifugal force during operation, and the blade must have sufficiently high dimensional stability, mechanical strength and flexural rigidity in order to operate normally. The quality of the blade depends on the quality of the blade mould, so that the high-precision and high-quality mould manufacturing technology is certainly the most concerned problem. In the manufacturing process of the existing blade mould, because the thermal expansion coefficients of the glass fiber and the epoxy resin are not matched and the curing heat generation cannot be released in time, and other factors influence, the inside of the mould inevitably generates residual stress, so that the mould generates larger deformation and cannot meet the corresponding requirement on the precision of the molded surface. At present, the more advanced monitoring technology in the world is the wireless laser tracker monitoring technology, and the technology has the advantages of high precision, high reliability, convenient carrying and the like, but the technology can only be carried out off line, and once the equipment is opened in the monitoring process, the equipment must be fixed in position and cannot be moved easily, and the adjusting mechanism is more complicated and time-consuming, and the monitoring technology is not suitable for being used under the dynamic and closed mold production working conditions of blade production, so that the monitoring technology which can be matched with the wireless laser tracker for use and can monitor the mold surface precision in real time is urgently needed in the actual production engineering. The fiber grating is used as a sensing element, takes an optical signal as a measurement information source, and has the advantages of small volume, high precision, water and moisture resistance, electromagnetic interference resistance, soft material, convenient implantation, easy net formation, real-time monitoring and the like.

Therefore, it is necessary to develop a wind turbine blade mold, a blade mold manufacturing method and a mold profile monitoring system for solving the above technical problems.

Disclosure of Invention

The invention not only can fully consider the production process and the manufacturing characteristics of the wind power blade mould, but also can solve the defect that the prior art can only carry out off-line detection, and aims to provide the wind power blade mould, the blade mould manufacturing method and the mould profile monitoring system so as to conveniently realize real-time on-line monitoring of the profile precision in the actual production process.

The above object of the present invention can be achieved by the following technical solutions:

in one aspect, the present invention provides a wind turbine blade mold, comprising: an upper die and a lower die;

the structure of last mould includes: an inner structural layer, a heating layer and an outer structural layer; the shape of the upper die is matched with the shape of the upper surface of the wind power blade; the structure of the lower die is the same as that of the upper die; the shape of the lower die is matched with the shape of the lower surface of the wind power blade; the upper die and the lower die are aligned and buckled;

the heating layer includes: the thermal grease is composed of a thermal grease layer formed by pouring and solidifying after mixing resin and a heat transfer medium, a copper pipe or a heating wire solidified in the grease layer, and a fiber grating; the fiber grating is arranged in the arrangement gap of the copper pipe or the heating wire;

a surface felt, an alkali-free cloth and a multi-axial multilayer fabric are arranged in the inner structure layer in a stacking mode; the connection mode between two adjacent surface felts is lap joint; the connection mode between two adjacent alkali-free cloths is lap joint; the connection mode between two adjacent multiaxial multilayer fabrics is lap joint; the inner structure layer is a solidified structure layer formed by pouring resin on the surface felt, the alkali-free cloth and the multi-axial multilayer fabric;

the outer structure layer is internally provided with a multi-axial multilayer fabric, balsawood and a multi-axial multilayer fabric in a sequential stacking manner; wherein, the connection mode of two adjacent multiaxial multilayer fabrics is lap joint; the connection mode of two adjacent balsawood is splicing; the outer structure layer is a solidified structure layer formed by adopting resin to solidify after vacuum-assisted infusion on the multi-axial multilayer fabric, the balsawood and the multi-axial multilayer fabric.

In some embodiments of the present invention, the fiber grating is formed by connecting a plurality of FBG bare gratings in series; the plurality of fiber gratings form a fiber Bragg grating in the heating layer, and the fiber gratings in the heating layer are not in contact with each other; in the optical fiber Bragg grating, a plurality of optical fiber gratings are connected to the same user interface together; the user interface is used for connecting the fiber grating demodulation system to realize wavelength division multiplexing.

In some embodiments of the present invention, the fiber grating is formed by connecting a plurality of FBG bare gratings in series; the plurality of fiber gratings form a fiber Bragg grating in the heating layer, and the fiber gratings in the heating layer are not in contact with each other; in the optical fiber Bragg grating, a plurality of optical fiber gratings are connected to the same user interface together; the user interface is used for connecting the fiber grating demodulator to realize wavelength division multiplexing.

In some embodiments of the present invention, the fiber grating is configured as a single optical fiber; the fiber bragg grating is formed by serially connecting a plurality of FBG bare gratings with different central wavelengths.

In some embodiments of the invention, a heat shrink tube for packaging protection is arranged at the welding point position where a plurality of the FBG bare grids are connected in series.

In some embodiments of the present invention, an insulating layer is further attached to an outer surface of the outer structural layer; the heat transfer medium is aluminum powder.

In some embodiments of the invention, the positions of the inner structure layer and the outer structure layer corresponding to the arrangement position of the fiber bragg grating are respectively provided with a groove with the shape matched with that of the fiber bragg grating; the depth of the groove is 0.5mm, and the width of the groove is 1 mm.

In another aspect, the present invention further provides a method for manufacturing a blade mold, including the following steps:

step 1: pouring resin on a multilayer structure formed by sequentially stacking a surfacing mat, alkali-free cloth and multi-axial multilayer fabric by adopting a vacuum auxiliary pouring process for preparing an inner structural layer of the blade mold; when the surface felt layer consists of a plurality of surface felts, the connection mode between two adjacent surface felts is lap joint; when the alkali-free cloth layer consists of a plurality of alkali-free cloths, the connection mode between two adjacent alkali-free cloths is lap joint; when the multi-axial multilayer fabric layer consists of a plurality of multi-axial multilayer fabrics, the connection mode between two adjacent multi-axial multilayer fabrics is lap joint; the manufacturing quantity of the inner structure layers of the blade mould is two, and the shapes of the inner structure layers are respectively matched with the shapes of the upper side and the lower side of the blade so as to obtain finished products of the inner structure layers of the upper mould and the lower mould;

step 2: after the upper die inner structure layer and the lower die inner structure layer are cured, presetting fiber bragg grating arrangement positions on one sides of the upper die inner structure layer and the lower die inner structure layer facing the blades respectively, or forming grooves at the fiber bragg grating arrangement positions;

and step 3: placing the fiber bragg grating at a preset fiber bragg grating setting position, and further laying a copper pipe or an electric heating wire on the same layer;

and 4, step 4: heating and mixing resin and a heat transfer medium, and pouring the mixture on one side of the upper die inner structure layer and one side of the lower die inner structure layer which face the blades respectively to form a heating layer; polishing and flattening the heating layer when the material is fully solidified to obtain a heating layer with uniform thickness;

and 5: laying a multilayer structure consisting of multi-axial multilayer fabric, balsa wood and multi-axial multilayer fabric on one side of the heating layer, which is used for facing the blade, and preparing an outer structure layer;

step 6: and adopting a vacuum auxiliary pouring process to pour resin on a multilayer structure consisting of the multiaxial multilayer fabric, the balsawood and the multiaxial multilayer fabric to form an outer structure layer, and polishing and flattening the outer structure layer after full solidification to obtain a finished blade mould product.

In some embodiments of the invention, further comprising: and 7: and an insulating layer is attached to the outer side of the outer structural layer.

In addition, the present invention also provides a mold surface monitoring system, comprising: the wind power blade mold and the fiber bragg grating demodulator are arranged on the wind power blade mold; the wind power blade mould is the wind power blade mould or the wind power blade mould manufactured according to the method; and the fiber grating demodulator is in signal connection with the fiber grating of the wind power blade mould through optical fibers.

In some embodiments of the present invention, a sealing bag is disposed at an optical fiber interface portion between the fiber grating demodulator and the fiber grating.

The invention has the characteristics and advantages that:

according to the invention, the production process and the manufacturing characteristics of the wind power blade mould are fully considered, the wind power blade mould with the built-in fiber grating sensor and stable structure and performance is prepared, the problem that the surface precision of a large wind power blade mould is difficult to monitor on line for a long time is solved, and a certain material basis is laid for an on-line monitoring system of the blade mould; according to the invention, the optical fiber is implanted into the blade mold structure to form the intelligent wind power blade mold, so that the real-time online monitoring of the surface precision of the wind power blade mold in the service process can be realized. The invention solves the difficult problems that the precision of the molded surface of the blade mold is difficult to monitor on line in the processing and preparation and the service process, and has the advantages of easy operation, one-time installation, long-term application and no influence on the overall performance of the mold; the invention adopts the fiber bragg grating formed by connecting a plurality of FBG bare gratings in series as a sensor, does not influence the strength and the rigidity of the die, and can monitor the internal strain and the temperature change of the die.

Furthermore, in the mold surface monitoring system provided by the invention, the fiber grating demodulator is internally provided with a super-radiation broadband light source, the light source is coupled to the field fiber grating detector through the coupler, each central wavelength reflected by the field fiber grating detector is reflected back to the coupler again, the coupler transmits a reflection signal to the wavelength detection unit, the central wavelength value reflected by each detector is sensed in the wavelength detection unit through the FP scanning technology, and the variation of the central wavelength of each detector is compared to calculate the environmental temperature, the strain and the like. The fiber grating demodulator outputs and displays the detected information, and outputs alarm signal when alarm information exists. In order to prevent the optical fiber interface from being polluted, the invention further arranges a sealing bag at the optical fiber interface between the optical fiber grating demodulator and the optical fiber grating, thereby providing powerful technical guarantee for high-precision data measurement.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural view of a wind turbine blade mold according to embodiment 1 of the present invention;

FIG. 2 is a structural sectional view taken along the line A in FIG. 1;

FIG. 3 is a schematic structural view of a heating layer portion in FIG. 2;

fig. 4 is a schematic layout view of an inner structure layer fiber grating sensor in embodiment 1 of the present invention;

fig. 5 is a schematic layout view of an outer structure layer fiber grating sensor in embodiment 1 of the present invention;

fig. 6 is a schematic diagram illustrating a connection relationship between core operation components of a mold profile monitoring system according to embodiment 3 of the present invention;

FIG. 7 is a schematic diagram illustrating the operation of wavelength division multiplexing associated with the mold profile monitoring system in embodiment 3 of the present invention;

fig. 8 is a graph illustrating a relationship between a variation of a center wavelength measured by a fiber grating and a variation of a displacement vector measured by a wireless laser tracker (single point) according to an embodiment of the present invention 3;

fig. 9 is a graph illustrating a relationship between a change amount of a center wavelength measured by a fiber grating and a change amount (multi-point) of a displacement vector measured by a wireless laser tracker according to an embodiment 3 of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.