High-precision kiln temperature automatic control method

Abstract

The invention discloses a high-precision kiln temperature automatic control method, and belongs to the technical field of glass production processes. The target temperature value T0 is set when the kiln works, the floatable range of the target temperature value T0 is T0 + / -n DEG C, the actual temperature value Tactual when the kiln works is measured in real time, the predicted temperature value TM after a period of time M is predicted through the temperature change slope k formed when the kiln works, the predicted temperature value TM is compared with the T0 + / -n DEG C, and the target temperature value T0 is calculated. And adjusting the predicted temperature value TM in the kiln after the time M to be within the range of T0 + / -n DEG C. Therefore, the automatic and accurate control of the kiln temperature is realized, the stability and the product yield of the kiln process are improved, and the labor intensity of operators is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of glass production processes, and in particular to a method for automatically controlling the temperature of a high-precision kiln. Background Art

[0002] In the production process of special glass, the stability of the kiln is crucial for production. Especially the temperature control of the kiln. Once temperature fluctuations occur, glass defects are very likely to fluctuate greatly. For example, stones, nodules, bubbles, etc. will fluctuate accordingly, which will have an adverse impact on the quality and good products. Currently, the kiln control has manual control and automatic control. Manual control is inseparable from personnel operation. It not only requires continuous monitoring and adjustment by personnel, but also due to different operators (experience, mental state and proficiency), the accuracy of manual control varies greatly, and fluctuations caused by personnel are also likely to occur. Automatic control can maintain fluctuations up and down at a certain temperature, but it is far from the process technology requirements, and the accuracy is still difficult to meet the process needs. Summary of the Invention

[0003] The main purpose of the present invention is to provide a method for automatically controlling the temperature of a high-precision kiln to solve the technical problem that it is difficult to control the temperature of the kiln within a certain temperature range in the process of glass production technology.

[0004] To achieve the above object, the present invention provides a method for automatically controlling the temperature of a high-precision kiln. The method for automatically controlling the temperature of a high-precision kiln includes: setting a target temperature value T when the kiln is operating, 0 where the floating range of the target temperature value T 0 is T 0 ±n °C. The actual temperature value T of the kiln during operation is measured in real time. 实 The predicted temperature value T after a period of time M is predicted through the temperature change slope k formed during the operation of the kiln. M The predicted temperature value T M is compared with the T 0 ±n °C. The predicted temperature value T in the kiln after the period of time M M is adjusted to within the range of the T 0 ±n °C.

[0005] In some embodiments of the present invention, the predicted temperature value T in the kiln after a period of time M is adjusted to within the range of the T M ±n °C by adjusting the adjustment amount Q of natural gas in the kiln. 0 ±n °C;

[0006] And / or, the range of the period of time M is 1 min to 120 min.

[0007] In some embodiments of the present invention, a preset temperature range is divided into m consecutive intervals according to the rule from low temperature to high temperature. The preset temperature range is greater than or equal to 0 °C. A coefficient N is set for each interval. The coefficient N is greater than 0 and increases as the temperature of the interval increases. According to the actual temperature value T 实 and the target temperature value T 0 the absolute value of the difference is calculated to obtain a temperature deviation value ΔT. The corresponding N value is selected according to the interval in which the temperature deviation value ΔT falls. At the same time, the reference adjustment range of the natural gas is set as a, where a is greater than 0, and the unit of a is Nm 3 / h. The adjustment amount Q of the natural gas is Q = ±N×a (Nm 3 / h).

[0008] In some embodiments of the present invention, the preset temperature range is divided into a first interval, a second interval, a third interval, a fourth interval, a fifth interval and a sixth interval in sequence according to the rule from low temperature to high temperature. The corresponding coefficients N are N1, N2, N3, N4, N5 and N6 respectively, satisfying N1 < N2 < N3 < N4 < N5 < N6.

[0009] In some embodiments of the present invention, the temperature range of the first interval is 0 °C ≤ T 1 ≤ 0.5 °C, the temperature range of the second interval is 0.5 °C < T 2 ≤ 1.0 °C, the temperature range of the third interval is 1.0 °C < T 3 ≤ 2.0 °C, the temperature range of the fourth interval is 2.0 °C < T 4 ≤ 5.0 °C, the temperature range of the fifth interval is 5.0 °C < T 5 ≤ 10.0 °C, and the temperature range of the sixth interval is 10.0 °C < T 6 .

[0010] In some embodiments of the present invention, when the actual temperature value T 实 is outside the floating range T 0 ±n °C of the target temperature value T 0 , and the predicted temperature value T M is also outside the T 0 ±n °C. When T M > T 实 , the adjustment amount Q of the natural gas is Q = -N×a (Nm 3 / h). When T M < T 实 , the adjustment amount Q of the natural gas is Q = N×a (Nm 3 / h).

[0011] In some embodiments of the present invention, when the actual temperature value T 实 is within the floating range T 0 of the target temperature value T 0 ±n°C, and the predicted temperature value T M is outside the T 0 ±n°C, when T M > T 实 , the adjustment amount Q of the natural gas is N×a (Nm 3 / h), and when T M < T 实 , the adjustment amount Q of the natural gas is -N×a (Nm 3 / h).

[0012] In some embodiments of the present invention, when the actual temperature value T 实 is within the floating range T 0 of the target temperature value T 0 ±n°C, and the predicted temperature value T M is outside the target temperature value T 0 ±n°C, when T M > T 实 , the adjustment amount Q of the natural gas is -N×a (Nm 3 / h), and when T M < T 实 , the adjustment amount Q of the natural gas is N×a (Nm 3 / h).

[0013] In some embodiments of the present invention, when the actual temperature value T 实 is within the floating range T 0 ±n°C of the target temperature value, and the predicted temperature value T M is within the target temperature value T 0 ±n°C, when T M > T 实 , the adjustment amount Q of the natural gas is N×a (Nm 3 / h), and when T M < T 实 , the adjustment amount Q of the natural gas is -N×a (Nm 3 / h).

[0014] In some embodiments of the present invention, the standard calorific value of natural gas is set as H, the calorific value change of natural gas is H 1 , and the approximate value Q 实 of the actual consumption of natural gas is Q = (H / H 1 ) × Q.

[0015] The beneficial effects that the present invention can achieve:

[0016] The present invention sets the target temperature value T when the kiln is operating 0 , and the floating range of the target temperature value T 0 is T 0 ±n°C. The actual temperature value T of the kiln during operation is measured in real time 实 , and the predicted temperature value T after a period of time M is predicted through the temperature change slope k formed during the operation of the kiln M . The predicted temperature value T M is compared with T 0 ±n°C, and the predicted temperature value T in the kiln after the time M has elapsed M is adjusted to within the range of T 0 ±n°C, thereby realizing the automatic and precise control of the kiln temperature, improving the stability of the kiln process and the product yield, and reducing the labor intensity of the operator. Specific embodiments

[0017] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] In the present invention, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0020] In the production process of special glass, the stability of the kiln is crucial for production, especially the temperature control of the kiln. Once temperature fluctuations occur, there is a high probability of significant fluctuations in glass defects. For example, stones, nodules, bubbles, etc. will fluctuate accordingly, which will have an adverse impact on quality and good products. Currently, there are manual control and automatic control for kiln control. Manual control relies on personnel operation. It not only requires continuous monitoring and adjustment by personnel, but also due to different operators (experience, mental state, and proficiency), the accuracy of manual control varies greatly, and fluctuations caused by personnel are also likely to occur. Automatic control can maintain fluctuations up and down at a certain temperature, but it is far from meeting the process technology requirements, and the accuracy is difficult to reach the process needs.

[0021] In view of this, the present invention provides a high-precision automatic control method for kiln temperature. The high-precision automatic control method for kiln temperature of the present invention includes: setting a target temperature value T when the kiln is operating 0 , the floating range of the target temperature value T 0 is T 0 ± n°C. The actual temperature value T 实 of the kiln during operation is measured in real time. The predicted temperature value T M after a period of time M is predicted through the temperature change slope k formed during the operation of the kiln. The predicted temperature value T M is compared with T 0 ± n°C, and the predicted temperature value T M in the kiln after a period of time M is adjusted to within the range of T 0 ± n°C.

[0022] In the present invention, the floating range of the target temperature value T 0 is T 0 ± n°C, where n°C > 0°C.

[0023] In the present invention, adjusting the predicted temperature value T M in the kiln after a period of time M to within the range of T 0 ± n°C can be understood as adjusting the actual temperature value T m after a period of time M to within the range of T 0 ± n°C. That is, according to the predicted temperature value T M , the actual temperature value T m after a period of time M is adjusted so that the actual temperature value T m after a period of time M falls within the range of T 0 ± n°C.

[0024] In the present invention, the temperature change slope k is the temperature change rate within the time period before the period of time M.

[0025] In some embodiments, the temperature change slope k can be calculated by temperature data collection, data fitting, etc.

[0026] Temperature data collection: Use a temperature sensor (such as a thermocouple or infrared thermometer) to monitor the temperature inside the kiln in real time, record the temperature change data over time, form a temperature-time curve, and calculate the temperature change slope k.

[0027] Data fitting: Fit the collected temperature-time data, usually using linear fitting or piecewise linear fitting. The slope of the straight line obtained after fitting is the temperature change slope k.

[0028] When using a kiln to burn glass, the fuel is usually natural gas. In some embodiments, the adjustment amount Q of the natural gas in the kiln is adjusted to change the predicted temperature value T in the kiln after the time M. M Adjust to the target temperature value floating range T 0 Within ±n℃.

[0029] In some embodiments, the period of time M ranges from 1 min to 120 min, and can be 1 min, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, etc.

[0030] In some embodiments, the preset temperature range is divided into m continuous intervals according to the rule from low temperature to high temperature. The preset temperature range is greater than or equal to 0°C. A coefficient N is set for each interval. The coefficient N is greater than 0. The coefficient N increases with the increase of the temperature of the interval. According to the actual temperature value T 实 and the target temperature value T 0 The temperature deviation value ΔT is calculated by the absolute value of the difference, and the corresponding N value is selected according to the interval in which the temperature deviation value ΔT falls. At the same time, the reference adjustment amplitude of the natural gas is set to a, a is greater than 0, and the unit of a is Nm 3 / h, the adjustment amount of natural gas Q = ±N×a (Nm 3 / h). When the natural gas consumption is adjusted to N×a (Nm 3 / h), which can be understood as increasing the amount of natural gas on the original basis. When the amount of natural gas is adjusted to -N×a(Nm 3 / h), which can be understood as reducing the amount of natural gas used on the original basis. In this embodiment, the preset temperature range includes the actual temperature value T 实 and the target temperature value T 0 The temperature deviation value ΔT is calculated by the absolute value of the difference.

[0031] In the present invention, the reference adjustment range of natural gas is a > 0, which can be set to a specific value according to requirements.

[0032] In the present invention, the coefficient N > 0, and the value of the coefficient N can be set to a specific value according to requirements.

[0033] In some embodiments, the absolute value of the difference between the N values corresponding to any adjacent intervals is less than or equal to 10, and can be 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, etc. This is beneficial to improving the precise control of the kiln temperature.

[0034] In some embodiments, the preset temperature range is divided into consecutive first, second, third, fourth, fifth, and sixth intervals according to the rule from low temperature to high temperature. The corresponding coefficients N are N1, N2, N3, N4, N5, and N6 respectively, satisfying N1 < N2 < N3 < N4 < N5 < N6.

[0035] In some embodiments, N2 - N1 ≤ 10, N3 - N2 ≤ 10, N4 - N3 ≤ 10, N5 - N4 ≤ 10, N6 - N5 ≤ 10. This is beneficial to improving the precise control of the kiln temperature.

[0036] In some embodiments, the temperature range of the first interval is 0°C ≤ T 1 ≤ 0.5°C, the temperature range of the second interval is 0.5°C < T 2 ≤ 1.0°C, the temperature range of the third interval is 1.0°C < T 3 ≤ 2.0°C, the temperature range of the fourth interval is 2.0°C < T 4 ≤ 5.0°C, the temperature range of the fifth interval is 5.0°C < T 5 ≤ 10.0°C, the temperature range of the sixth interval is 10.0°C < T 6 .

[0037] In some embodiments, when the actual temperature value T 实 is outside the floating range T 0 ±n°C of the target temperature value, and the predicted temperature value T M is outside T 0 ±n°C, and the predicted temperature value T M is too high or too low, it is necessary to adjust to make the actual temperature value after a period of time M fall within the range of T 0 ±a°C. When T M > T 实 , that is, the predicted temperature value TM is higher than the actual temperature value T 实 , then it is necessary to reduce the consumption of natural gas based on the actual temperature value T 实 to make the actual temperature value after a period of time M fall within T 0Within the range of ±a °C, in this embodiment, the actual temperature value T can be used according to the actual situation. 实 and the target temperature value T 0 The temperature deviation value ΔT is calculated based on the absolute value of the difference. According to the interval in which the temperature deviation value ΔT falls, the corresponding N value is selected. At the same time, the reference adjustment range of natural gas is set as a, where a > 0, and the unit of a is Nm 3 / h, and the adjustment amount Q of natural gas = -N × a (Nm 3 / h). When T M <T 实 , that is, the predicted temperature value T M is lower than the actual temperature value T 实 , then it is necessary to increase the consumption of natural gas based on the actual temperature value T 实 so that the actual temperature value after a period of time M falls within T 0 ±a °C. In this embodiment, the actual temperature value T can be used according to the actual situation. 实 and the target temperature value T 0 The temperature deviation value ΔT is calculated based on the absolute value of the difference. According to the interval in which the temperature deviation value ΔT falls, the corresponding N value is selected. At the same time, the reference adjustment range of natural gas is set as a, where a > 0, and the unit of a is Nm 3 / h, and the adjustment amount Q of natural gas = N × a (Nm 3 / h).

[0038] In some embodiments, when the actual temperature value T 实 is outside the range of the target temperature value T 0 ±n °C, and the predicted temperature value T M is within the range of the target temperature value T 0 ±n °C, the actual temperature value T 实 can be controlled to maintain the predicted temperature value TM, ensuring that the actual temperature value after a period of time M falls within T 0 ±a °C. When T M >T 实 , that is, the actual temperature value T 实 is lower than the predicted temperature value T M , then it is necessary to increase the consumption of natural gas based on the actual temperature value T 实 to raise the actual temperature value T 实 , so as to ensure that the actual temperature value after a period of time M reaches the predicted temperature value T M , and remains within the range of T 0 ±a °C. In this embodiment, the actual temperature value T can be used according to the actual situation. 实 and the target temperature value T 0 The temperature deviation value ΔT is calculated based on the absolute value of the difference. According to the interval in which the temperature deviation value ΔT falls, the corresponding N value is selected. At the same time, the reference adjustment range of natural gas is set as a, where a > 0, and the unit of a is Nm3 / h, the adjustment amount of natural gas is N×a (Nm 3 / h). When T M <T 实 , that is, the actual temperature value T 实 is higher than the predicted temperature value T M , it is necessary to reduce the consumption of natural gas based on the actual temperature value T 实 to lower the actual temperature value T 实 so as to ensure that the actual temperature value after a period of time M reaches the temperature value T M and remains within the range of T 0 ±a °C. In this embodiment, the temperature deviation value ΔT can be calculated according to the absolute value of the difference between the actual temperature value T 实 and the target temperature value T 0 . The corresponding N value is selected according to the interval in which the temperature deviation value ΔT falls. At the same time, the reference adjustment range of natural gas is set as a, a>0, and the unit of a is Nm 3 / h, and the adjustment amount of natural gas is Q = -N×a (Nm 3 / h).

[0039] In some embodiments, when the actual temperature value T 实 is within ±n °C of the target temperature value T 0 , and the predicted temperature value T M is outside the target temperature value T 0 ±n °C, it is necessary to adjust the actual temperature value T 实 to control the actual temperature value after a period of time M within T 0 ±a °C. When T M >T 实 , that is, the predicted temperature value TM is higher than the actual temperature value T 实 , it is necessary to reduce the consumption of natural gas based on the actual temperature value T 实 to lower the temperature and prevent the actual temperature value after a period of time M from reaching the predicted temperature value T M and thus exceeding the range of T 0 ±a °C. In this embodiment, the temperature deviation value ΔT can be calculated according to the absolute value of the difference between the actual temperature value T 实 and the target temperature value T 0 . The corresponding N value is selected according to the interval in which the temperature deviation value ΔT falls. At the same time, the reference adjustment range of natural gas is set as a, a>0, and the unit of a is Nm 3 / h, and the adjustment amount of natural gas is Q = -N×a (Nm 3 / h). When T M <T 实 , that is, the predicted temperature value TM is lower than the actual temperature value T 实 , it is necessary to increase the consumption of natural gas based on the actual temperature value T实 Based on this, increase the amount of natural gas used to prevent the actual temperature value after a period of M from dropping below the predicted temperature value T M and thus exceeding the range of T 0 ±a °C. In this embodiment, the temperature deviation value ΔT can be calculated based on the absolute value of the difference between the actual temperature value T 实 and the target temperature value T 0 . Select the corresponding N value according to the interval in which the temperature deviation value ΔT falls. At the same time, set the reference adjustment range of natural gas as a, where a > 0, and the unit of a is Nm 3 / h. The amount of natural gas used is adjusted to Q = N × a (Nm 3 / h).

[0040] In some embodiments, when the actual temperature value T 实 is within ±n °C of the target temperature value T 0 , and the predicted temperature value T M is within ±n °C of the target temperature value T 0 , the actual temperature value T 实 can be adjusted to control the actual temperature value after a period of M to reach the predicted temperature value T M and fall within T 0 ±a °C. When T M > T 实 , that is, the predicted temperature value T M is higher than the actual temperature value T 实 , then it is necessary to increase the amount of natural gas used based on the actual temperature value T 实 so that the actual temperature value T 实 approaches the predicted temperature value T M . Therefore, the amount of natural gas used is adjusted to Q = N × a (Nm 3 / h). When T M < T 实 , that is, the actual temperature value T 实 is higher than the predicted temperature value TM, it is necessary to reduce the amount of natural gas used based on the actual temperature value T 实 to lower the actual temperature value T 实 so that the actual temperature value T 实 approaches the predicted temperature value T M . Therefore, the amount of natural gas used is adjusted to Q = -N × a (Nm 3 / h).

[0041] In the process of adjusting the temperature of the kiln furnace using natural gas, the amount of natural gas used is usually related to the calorific value of natural gas. The calorific value of natural gas refers to the heat released when a unit volume or unit mass of natural gas is completely burned, usually in megajoules per cubic meter (MJ / m 3 ) or kilocalories per cubic meter (kcal / m 3) It is shown that when the calorific value of natural gas changes, the consumption of natural gas can be changed accordingly to improve the accuracy of controlling the temperature of the kiln.

[0042] In some embodiments, the standard calorific value of natural gas is set as H, and the change in the calorific value of natural gas is ΔH 1 , and the approximate value Q of the actual consumption of natural gas 实 = (H / (H + ΔH)) × Q, with the unit of Nm 1 ³ / h, where Q is the adjustment amount of natural gas calculated before the change in the calorific value of natural gas. 3 The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

[0043] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A high-precision kiln temperature automatic control method, characterized in that: The high-precision kiln temperature automatic control method comprises: setting a target temperature value T0 when the kiln is working, wherein the floating range of the target temperature value T0 is T0±n°C, and measuring the actual temperature value T0 of the kiln when working in real time. 实 The predicted temperature value T after a period of time M is predicted by the temperature change slope k formed when the kiln is working. M , the predicted temperature value T M Compared with the T0±n℃, the predicted temperature value T in the kiln after the period M is M Adjust to within the range of T0±n℃.

2. The high-precision kiln temperature automatic control method according to claim 1 is characterized in that: By adjusting the adjustment amount Q of the natural gas in the kiln to change the predicted temperature value T in the kiln after time M M Adjust to within the range of T0±n℃; And / or, the period of time M ranges from 1 min to 120 min.

3. The high-precision kiln temperature automatic control method according to claim 2 is characterized in that: The preset temperature range is divided into m continuous intervals according to the rule from low temperature to high temperature, the preset temperature range is greater than or equal to 0°C, and a coefficient N is set for each interval, the coefficient N is greater than 0, and the coefficient N increases with the increase of the temperature of the interval, according to the actual temperature value T 实 The temperature deviation value ΔT is calculated by the absolute value of the difference between the temperature deviation value ΔT and the target temperature value T0. The corresponding N value is selected according to the interval in which the temperature deviation value ΔT falls. At the same time, the reference adjustment amplitude of the natural gas is set to a, a is greater than 0, and the unit of a is Nm 3 / h, the adjustment amount of natural gas Q = ±N×a (Nm 3 / h).

4. The high-precision kiln temperature automatic control method according to claim 3 is characterized in that: The preset temperature range is divided into continuous first, second, third, fourth, fifth and sixth intervals according to the rule from low temperature to high temperature, and the corresponding coefficients N are N1, N2, N3, N4, N5 and N6, respectively, satisfying N1<N2<N3<N4<N5<N6.

5. The high-precision kiln temperature automatic control method according to claim 4 is characterized in that: The temperature range of the first interval is 0℃≤T1≤0.5℃, the temperature range of the second interval is 0.5℃<T2≤1.0℃, the temperature range of the third interval is 1.0℃<T3≤2.0℃, the temperature range of the fourth interval is 2.0℃<T4≤5.0℃, the temperature range of the fifth interval is 5.0℃<T5≤10.0℃, and the temperature range of the sixth interval is 10.0℃<T6.

6. The high-precision kiln automatic control method according to any one of claims 3 to 5, characterized in that: The actual temperature value T 实 Outside the floating range T0±n°C of the target temperature value T0, the predicted temperature value T M Outside the T0±n℃, when T M >T 实 The adjustment amount of natural gas Q = -N × a (Nm 3 / h), when T M <T 实 The adjustment amount of natural gas Q = N × a (Nm 3 / h).

7. The high-precision kiln automatic control method according to claim 1, characterized in that: When the actual temperature value T 实 Outside the floating range T0±n°C of the target temperature value T0, the predicted temperature value T M Within the T0±n℃, when T M >T 实 The adjustment amount of natural gas Q = N × a (Nm 3 / h), when T M <T 实 The adjustment amount of natural gas Q = -N × a (Nm 3 / h).

8. The high-precision kiln automatic control method according to claim 1, characterized in that: When the actual temperature value T 实 Within the floating range T0±n°C of the target temperature value T0, the predicted temperature value T M Outside the target temperature value T0±n℃, when T M >T 实 The adjustment amount of natural gas Q = -N × a (Nm 3 / h), when T M <T 实 The adjustment amount of natural gas Q = N × a (Nm 3 / h).

9. The high-precision kiln automatic control method according to claim 1, characterized in that: When the actual temperature value T 实 Within the floating range T0±n℃ of the target temperature value, the predicted temperature value T M Within the target temperature value T0±n℃, when T M >T 实 The adjustment amount of natural gas Q = N × a (Nm 3 / h), when T M <T 实 The adjustment amount of natural gas Q = -N × a (Nm 3 / h).

10. The high-precision kiln automatic control method according to any one of claims 2 to 9, characterized in that: The standard natural gas calorific value is set to H, the calorific value change of natural gas is set to H1, and the actual amount of natural gas is set to Q 实 =(H / H1)×Q.