阅读说明：本技术 基于静态法的干式绝缘设备活化能获取方法 (Method for acquiring activation energy of dry-type insulation equipment based on static method ) 是由 张心洁 张鑫 郗晓光 刘力卿 马昊 王伟 张弛 李佳龙 马小光 朱旭亮 于 2019-12-09 设计创作，主要内容包括：本发明公开了一种基于静态法的干式绝缘设备活化能获取方法,所述方法将静态法与阿伦尼乌斯方程相结合,能够从热失重实验数据实现活化能的准确测取,为干式绝缘设备老化状态评估奠定了基础。本申请结合静态法具有如下优点：1、实验和仪器简单,通过常规的DTG分析结果即可求取活化能；2、原理明确,计算简便,活化能计算结果认可度高,可以用于干式绝缘设备老化程度和剩余寿命的定量评估。3、在干式绝缘材料老化过程中不伴有热效应的老化阶段,活化能计算的准确度较高。(The invention discloses a method for acquiring activation energy of dry-type insulation equipment based on a static method, which combines the static method with an Allen-nius equation, can realize accurate measurement of the activation energy from thermogravimetric experiment data and lays a foundation for evaluating the aging state of the dry-type insulation equipment. The application has the following advantages by combining the static method: 1. the experiment and the instrument are simple, and the activation energy can be obtained through the conventional DTG analysis result; 2. the principle is clear, the calculation is simple and convenient, the recognition degree of the activation energy calculation result is high, and the method can be used for quantitatively evaluating the aging degree and the residual life of the dry-type insulation equipment. 3. The calculation accuracy of the activation energy is higher in the aging stage without thermal effect in the aging process of the dry insulating material.)

1. A method for acquiring activation energy of dry-type insulation equipment based on a static method is characterized by comprising the following steps:

in the thermal ageing reaction of dry insulation equipment, the assumption exists that the epoxy polymer reaction process depends only on the conversion α and the temperature T, which are independent of each other, and the kinetic equation of the heterogeneous reaction at an indefinite temperature can be expressed in the form:

in the formula (1), t is time, k (T) is a temperature relation of a rate constant, and f (α) is a reaction mechanism function;

in the field operation aging process of the dry type insulation equipment, different aging stages are clearly separated; for one of the aging stages, the aging reaction is a single chemical reaction; the static method is a method for measuring the rate equation of a single chemical reaction and the relation between a rate constant and temperature under the conditions of constant temperature and constant pressure;

for the premise of constant temperature and pressure, k (t) in formula (1) is a constant value that does not change with time, and can be recorded as:

k(T)＝C (2)

in the above formula, C is a constant;

the activation energy calculation method based on the static method is described in two cases:

(a) when the reaction mechanism function is known, equation (1) is integrated to obtain:

describing k (t) in formula (3) with the arrhenius formula, we can obtain:

since α and t are known, the reaction mechanism function f (α) is also known, and two different sets of α and t can be taken to form a binary equation system of the chemical reaction activation energy E and the pre-exponential factor A, so as to obtain the activation energy E;

(b) the reaction mechanism function is unknown, and the same integration of equation (1) can be found:

at a reaction temperature of T₁When the reaction conversion α is selected to correspond to a time t₁The above equation will become:

at a reaction temperature of T₂When the reaction conversion α is selected to correspond to a time t₂The above equation will become:

since the same reaction, the same reaction function f (α) and the same conversion rate are obtained, the same applies to

k(T₁)t₁＝k(T₂)t₂(8)

k (T) in formula (8) is described by Arrhenius formula, and the obtained product

The chemical reaction activation energy E of the reaction can be determined by solving equation (9).

Technical Field

The invention relates to the technical field of transformer operation and test, in particular to a method for acquiring activation energy of dry-type insulation equipment based on a static method.

Background

Arrhenius believes that there are two classes of molecules in a chemical reaction, the activated molecule and the non-activated molecule. The former has higher energy than the latter by Ea, and is the activation energy. Taking the sucrose reaction as an example, a non-activated sucrose molecule cannot cause a reaction, and only if it absorbs energy Ea to become an activated sucrose molecule, the reaction occurs. Particularly, in the dry insulating material of the power transmission and transformation equipment, the dry insulating material with good insulating property has a difference with the activation energy of the dry insulating material with degraded insulation or to be degraded, and the size of the difference indicates the degradation trend of the material in the next step. Therefore, the insulation aging degree of the dry-type insulation material can be detected by measuring the activation energy of the dry-type insulation material. Through search, no activation energy acquisition method applicable to dry insulation equipment exists at present.

The static method is a method for measuring a rate equation of reaction and a relation between a rate constant and temperature under the conditions of constant temperature and constant pressure, and has the characteristics of simple principle and simple and convenient calculation for chemical reactions with relatively stable reaction stages and definite reaction mechanisms. The patent combines a static method and an arrhenius equation, and provides a method for acquiring the activation energy of dry-type insulation equipment based on the static method.

Disclosure of Invention

In order to meet the requirement of acquiring the activation energy of the dry type insulation equipment in the prior art, the invention aims to provide a method for acquiring the activation energy of the dry type insulation equipment based on a static method.

In order to achieve the aim of the invention, the invention provides a method for acquiring the activation energy of dry type insulation equipment based on a static method,

in the thermal ageing reaction of dry insulation equipment, the assumption exists that the epoxy polymer reaction process depends only on the conversion α and the temperature T, which are independent of each other, and the kinetic equation of the heterogeneous reaction at an indefinite temperature can be expressed in the form:

in the formula (1), t is time, k (T) is a temperature relation of a rate constant, and f (α) is a reaction mechanism function;

in the field operation aging process of the dry type insulation equipment, different aging stages are clearly separated; for one of the aging stages, the aging reaction is a single chemical reaction; the static method is a method for measuring the rate equation of a single chemical reaction and the relation between a rate constant and temperature under the conditions of constant temperature and constant pressure;

for the premise of constant temperature and pressure, k (t) in formula (1) is a constant value that does not change with time, and can be recorded as:

k(T)＝C (2)

in the above formula, C is a constant;

the activation energy calculation method based on the static method is described in two cases:

(a) when the reaction mechanism function is known, equation (1) is integrated to obtain:

describing k (t) in formula (3) with the arrhenius formula, we can obtain:

since α and t are known, the reaction mechanism function f (α) is also known, and two different sets of α and t can be taken to form a binary equation system of the chemical reaction activation energy E and the pre-exponential factor A, so as to obtain the activation energy E;

(b) the reaction mechanism function is unknown, and the same integration of equation (1) can be found:

at a reaction temperature of T₁When the reaction conversion α is selected to correspond to a time t₁The above equation will become:

at a reaction temperature of T₂When the reaction conversion α is selected to correspond to a time t₂The above equation will become:

since the same reaction, the same reaction function f (α) and the same conversion rate are obtained, the same applies to

Are equal, subtracting the two equations yields:

k(T₁)t₁＝k(T₂)t₂(8)

k (T) in formula (8) is described by Arrhenius formula, and the obtained product

The chemical reaction activation energy E of the reaction can be determined by solving equation (9).

Compared with the prior art, the method has the advantages that the activation energy of the dry-type insulation equipment can be quantitatively calculated on the basis of the thermal weight loss test by using the method for acquiring the activation energy of the dry-type insulation equipment based on the static method;

in addition, the static method is combined, and the following advantages are achieved:

1. the experiment and the instrument are simple, and the activation energy can be obtained through the conventional DTG analysis result;

2. the principle is clear, the calculation is simple and convenient, the recognition degree of the activation energy calculation result is high, and the method can be used for quantitatively evaluating the aging degree and the residual life of the dry-type insulation equipment.

3. The calculation accuracy of the activation energy is higher in the aging stage without thermal effect in the aging process of the dry insulating material.

Detailed Description

The present invention will be described in further detail with reference to specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

The thermal weight loss is that the substance is heated to gradually volatilize and decompose, and the change of the weight of the substance along with the rise of the temperature is measured. This can be used to determine certain physical properties of the material, such as parameters of decomposition temperature, melting point, and the like. On the basis of a thermal weight loss experiment, a method for acquiring the activation energy of dry-type insulation equipment based on a static method can be deduced.

In the thermal ageing reaction of dry insulation equipment, the assumption exists that the epoxy polymer reaction process depends only on the conversion α and the temperature T, which are independent of each other, and the kinetic equation of the heterogeneous reaction at an indefinite temperature can be expressed in the form:

in the formula (1), t is time, k (T) is a temperature relation of rate constant, and f (α) is a function of reaction mechanism.

In the field operation aging process of the dry-type insulation equipment, different aging stages are clearly separated. For one of the aging stages, the aging reaction is a single chemical reaction. The static method is a method for measuring the rate equation of a single chemical reaction and the relation between a rate constant and temperature under the conditions of constant temperature and constant pressure.

For the premise of constant temperature and pressure, k (t) in formula (1) is a constant value that does not change with time, and can be recorded as:

k(T)＝C (2)

in the above formula, C is a constant.

The activation energy calculation method based on the static method is described in two cases:

(a) when the reaction mechanism function is known, equation (1) is integrated to obtain:

k (T) in formula (7) is described by Arrhenius formula, and the obtained product

Since α and t are known, the reaction mechanism function f (α) is also known, and the activation energy E can be obtained by taking two different sets of α and t to form a binary equation system of the chemical reaction activation energy E and the pre-exponential factor A.

(b) The function of the reaction mechanism is unknown, and the same integral on the equation (1) can be obtained

At a reaction temperature of T₁When the reaction conversion α is selected to correspond to a time t₁The above equation will become

At a reaction temperature of T₂When the reaction conversion α is selected to correspond to a time t₂The above-mentionedThe equation will become

Since the same reaction, the same reaction function f (α) and the same conversion rate are obtained, the same applies to

Are equal, subtracting the two equations yields

k(T₁)t₁＝k(T₂)t₂(8)

K (T) in formula (8) is described by Arrhenius formula, and the obtained product

The chemical reaction activation energy E of the reaction can be determined by solving equation (9).

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.