Compressor torque detection method for wind energy cogeneration unit

Abstract

The invention provides a compressor torque detection method of a wind energy combined heat and power unit, belongs to the technical field of wind energy combined heat and power, and particularly relates to a compressor rotating speed-torque curve of a compressor under different sliding valve opening degrees; the rotating speed interval of the actual rotating speed value of the compressor in the rotating speed-torque curve of the compressor is judged; judging a sliding valve opening interval of the actual sliding valve opening value of the compressor in the rotating speed-rotating speed curve of the compressor; function images corresponding to the upper limit and the lower limit of the current sliding valve opening interval are determined, torque values corresponding to the upper limit and the lower limit of the current sliding valve opening interval are calculated according to the function images corresponding to the upper limit and the lower limit and the actual rotating speed value of the compressor, and the torque values are recorded as an upper-limit torque value and a lower-limit torque value respectively; and calculating the actual torque of the compressor according to the upper limit torque value, the lower limit torque value and the actual opening value of the sliding valve of the compressor. And the accuracy of detecting the torque of the compressor of the wind energy combined heat and power unit is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind energy heat and power cogeneration, and particularly to a compressor torque detection method of a wind energy heat and power cogeneration unit. BACKGROUND

[0002] With the development of wind energy heat utilization technology, a wind energy heat and power cogeneration technology is proposed to improve the utilization rate of wind resources by directly converting the mechanical energy of a wind turbine into heat energy. The mechanism of the wind heat part of the wind energy heat and power cogeneration unit is different from that of the traditional wind turbine. The mechanism of the wind heat part is as follows: the wind turbine directly drives the compressor to rotate and work through a speed increaser, and the compressor in the nacelle is connected with the ground heat pump through a metal hose to realize efficient heating or refrigeration.

[0003] The operation mechanism of the wind power part of the wind energy heat and power cogeneration unit is as follows: when operating at the rated wind speed, the pitch angle is fully opened, the rotational speed is controlled by the generator torque, and the wind turbine operates at the optimal tip speed ratio, and the rotational speed of the wind wheel accurately tracks the change of the wind speed. When operating above the rated wind speed, the wind turbine is put into the variable pitch control system, the pitch angle is changed to adjust the wind energy utilization of the wind turbine, and the rotational speed of the wind turbine is controlled. Due to the large inertia of the impeller, the response of the variable pitch control is lagged, so the generator torque control should also be coupled above the rated wind speed to ensure the high-quality output of energy in the power generation mode. During power generation, the electromagnetic torque of the generator can be read from the communication data of the power generation system inverter as the actual value feedback of the electromagnetic torque. The system sends the given torque value to the inverter as the communication data.

[0004] The operation mechanism of the wind heat part of the wind energy heat and power cogeneration unit is as follows: the impeller of the wind turbine is connected with the compressor through a speed increaser. Since the compressor cannot be connected to the grid, the main CPU of the PLC cannot directly read the torque of the compressor. The system adjusts the rotational speed of the compressor and the position of the slide valve to adjust the torque of the compressor. Due to the space limitation in the nacelle, it is difficult to install a torque sensor on the shaft connecting the speed increaser and the compressor. The torque sensor has a large error in detecting data and the feedback data is unreliable due to the vibration in the nacelle during the operation of the wind turbine, which cannot meet the control requirements. SUMMARY

[0005] Therefore, the present application provides a compressor torque detection method of a wind energy heat and power cogeneration unit to solve the problems in the prior art and improve the accuracy of the compressor torque detection of the wind energy heat and power cogeneration unit.

[0006] The compressor torque detection method of the wind energy heat and power cogeneration unit provided by the present application adopts the following technical scheme: A compressor torque detection method of a wind energy heat and power cogeneration unit, comprising the following steps: fitting the compressor speed-torque curve of the compressor at different slide valve openings; The actual compressor speed value is obtained, and it is determined that the actual compressor speed value is located in a speed interval in the compressor speed-torque curve, which is recorded as a current running speed interval; The function image in the current speed interval under different compressor slide valve openings is recorded; The actual compressor slide valve opening value is obtained, and it is determined that the actual compressor slide valve opening value is located in a slide valve opening interval in the compressor speed-speed curve, which is recorded as a current running slide valve opening interval; The function images corresponding to the upper limit and the lower limit of the current slide valve opening interval are determined, which are recorded as an upper limit broken line and a lower limit broken line, respectively. The slopes corresponding to the upper limit broken line and the lower limit broken line, the lower limit value of the current running speed interval, and the torque value corresponding to the lower limit value of the current running speed interval are calculated. The linear expressions of the upper limit broken line and the lower limit broken line are established, which are recorded as a first expression and a second expression, respectively; The torque values corresponding to the upper limit and the lower limit of the current running slide valve opening interval are calculated by combining the first expression, the second expression, and the actual compressor speed value, which are recorded as an upper limit torque value and a lower limit torque value, respectively. The linear expression of the compressor torque and the slide valve opening in the current running slide valve opening interval is established according to the upper limit torque value and the lower limit torque value, which is recorded as a third expression. The actual compressor slide valve opening value is substituted into the third expression to obtain the actual compressor torque.

[0007] Optionally, the step of fitting the compressor speed-torque curve of the compressor under different slide valve openings comprises: Before the compressor is installed in the cabin, the compressor is filled with refrigerant by simulating the operation process of the wind-heat combined power generation unit. Under different compressor slide valve openings, the compressor speed is adjusted from low to high, and the torque under different speeds is measured. According to the measured compressor speed and torque data, a multi-segment broken line method is used to fit the compressor speed-torque curve under different slide valve openings.

[0008] Optionally, the wind turbine impeller encoder data is read by the main CPU of the wind-heat combined power generation unit control system, the actual impeller speed is calculated, and the actual compressor speed value is calculated by multiplying the actual impeller speed by the speed ratio of the speed increasing box.

[0009] Optionally, during the process of obtaining the actual compressor speed value, if the calculated actual compressor speed value exceeds the rated compressor speed, the current actual compressor speed value is determined as the rated compressor speed.

[0010] Optionally, the actual compressor slide valve opening value is calculated by reading the slide valve opening sensor signal through the main CPU of the wind-heat combined power generation unit control system.

[0011] Optionally, during the process of calculating the actual compressor slide valve opening value, if the calculated actual compressor slide valve opening value is less than 10%, the current actual compressor slide valve opening value is determined as 10%. If the calculated compressor slide valve opening actual value is greater than 100%, it is determined that the current compressor slide valve opening actual value is 100%.

[0012] Optionally, the first expression is Y1 = y 0i j下 + k i j 下 (x―x 0j ); Wherein, Y1 represents the compressor torque at different compressor speeds on the lower limit broken line; y 0i j下 represents the torque value corresponding to the lower limit value of the current running speed interval on the lower limit broken line; k i j下 represents the slope of the lower limit broken line; x 0j represents the lower limit value of the current running speed interval of the compressor; x represents the compressor speed; The second expression is Y2 = y 0i j上 + k i j 上 (x―x 0j ); Y2 represents the compressor torque at different compressor speeds on the upper limit broken line; y 0i j上 represents the torque value corresponding to the lower limit value of the current running speed interval on the upper limit broken line; k i j上 represents the slope of the upper limit broken line; x represents the compressor speed; The third expression is Y = Y 下 +(Y 上 -Y 下 )(z―z i ) / (z i+1 ―z i ); Wherein, Y represents the actual compressor torque at different compressor slide valve openings at the actual value of the compressor speed; Y 下 represents the lower limit torque value; Y 上 represents the upper limit torque value; z represents the compressor slide valve opening; z i+1 represents the upper limit value of the current running slide valve opening interval; z i represents the lower limit value of the current running slide valve opening interval; In summary, the present application includes the following beneficial technical effects: The detection method of the application ensures that the wind energy cogeneration unit control system can accurately read the compressor torque in real time, solves the problems that the torque sensor is difficult to install and the feedback data is unreliable due to the space limitation and cabin vibration in the cabin, and cannot accurately and timely collect the actual torque of the compressor. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0014] Figure 1 The compressor speed-torque curve diagram of the compressor under different slide valve opening degrees. DETAILED DESCRIPTION

[0015] The embodiments of the application will be described in detail below with reference to the drawings.

[0016] The embodiments of the application will be described in detail below with reference to the drawings.

[0017] It should be noted that the various aspects described below in the context of the accompanying claims are illustrative and not restrictive. It should be apparent to those skilled in the art that the aspects described herein can be carried out in a wide variety of forms and that any specific structure and / or function described herein is merely illustrative. Based on the application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect and that two or more of these aspects can be combined in various ways. For example, any number of the aspects described herein can be used to implement a device and / or practice a method. In addition, other structures and / or functionality can be used in addition to or in place of the aspects described herein.

[0018] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0019] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0020] This application provides a method for detecting the compressor torque of a wind power combined heat and power unit.

[0021] A method for detecting the compressor torque of a wind-powered combined heat and power unit includes the following steps: like Figure 1 As shown, the compressor speed-torque curves are fitted under different slide valve openings; Obtain the actual compressor speed value and determine the speed range in the compressor speed-torque curve where the actual compressor speed value is located, and record it as the current operating speed range; Record the function graph of different compressor slide valve openings within the current speed range; Obtain the actual value of the compressor slide valve opening, and determine the slide valve opening range in which the actual value of the compressor slide valve opening is located in the compressor speed-speed curve, and record it as the current operating slide valve opening range; Determine the function graphs corresponding to the upper and lower limits of the current valve opening range, denoted as the upper limit broken line and the lower limit broken line, respectively. Calculate the slopes of the upper limit broken line and the lower limit broken line, the lower limit value of the current operating speed range, and the torque value corresponding to the lower limit value of the current operating speed range. Establish linear expressions for the upper limit broken line and the lower limit broken line, denoted as the first expression and the second expression, respectively. Combining the first expression, the second expression, and the actual compressor speed, the torque values ​​corresponding to the upper and lower limits of the current operating slide valve opening range at the actual compressor speed are calculated and denoted as the upper limit torque value and the lower limit torque value, respectively. Based on the upper limit torque value and the lower limit torque value, a linear expression for the compressor torque and slide valve opening within the current operating slide valve opening range is established and denoted as the third expression. Substituting the actual compressor slide valve opening value into the third expression, the actual compressor torque is obtained.

[0022] The steps for fitting the compressor speed-torque curves under different slide valve openings include: before the compressor is installed in the nacelle, refrigerant is charged into the compressor simulating the operation process of a wind power cogeneration unit; under different compressor slide valve openings, the compressor speed is adjusted from low to high and the torque at different speeds is measured; based on the measured compressor speed and torque data, the compressor speed-torque curves under different slide valve openings are fitted using a multi-segment broken line method.

[0023] The main CPU of the wind turbine cogeneration unit control system reads data from the wind turbine impeller encoder to calculate the actual impeller speed. This actual impeller speed is then multiplied by the speed ratio of the speed booster box to calculate the actual compressor speed. If the calculated actual compressor speed exceeds the compressor's rated speed, then the current actual compressor speed is considered to be the rated compressor speed.

[0024] The main CPU of the wind-powered combined heat and power unit control system reads the valve opening sensor signal and calculates the actual value of the compressor valve opening. During the calculation, if the calculated actual value is less than 10%, the current actual value is considered to be 10%; if the calculated actual value is greater than 100%, the current actual value is considered to be 100%.

[0025] In this embodiment of the application, the first expression is Y1 = y 0i j下 + k i j 下 (x―x 0j ); Where Y1 represents the compressor torque at different compressor speeds on the lower limit curve; y 0i j下 This indicates the torque value corresponding to the lower limit value of the current operating speed range on the lower limit curve; k i j下 Indicates the slope of the lower limit line; x 0j This indicates the lower limit of the compressor speed within the current operating speed range; x represents the compressor speed; Substituting the actual compressor speed value into the first expression, i.e., x is the actual compressor speed value, we obtain the lower limit torque value Y corresponding to the lower limit of the current operating slide valve opening range under the actual compressor speed value. 下 .

[0026] The second expression is Y2 = y 0i j上 + k i j 上 (x―x 0j ); Y2 represents the compressor torque at different compressor speeds on the upper limit curve; y0i j上 This indicates the torque value corresponding to the lower limit of the current operating speed range on the upper limit curve. k i j上 This indicates the slope of the upper limit line; x represents the compressor speed; Substituting the actual compressor speed value into the second expression, i.e., x is the actual compressor speed value, yields the upper limit torque value Y corresponding to the upper limit of the current operating slide valve opening range under the actual compressor speed value. 上 .

[0027] The third expression is Y = Y 下 +(Y 上 -Y 下 (z―z) i ) / (z i+1 ―z i ); Where Y represents the actual torque of the compressor under different compressor slide valve openings at the actual compressor speed; Y 下 Indicates the lower limit torque value; Y 上 Indicates the upper limit torque value; z represents the compressor slide valve opening degree; z i+1 This indicates the upper limit of the current operating spool valve opening range; z i This indicates the lower limit of the current operating spool valve opening range; Substitute the actual value of the current compressor slide valve opening into the third expression, that is, z takes the actual value of the compressor slide valve opening, to obtain the actual compressor torque.

[0028] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for detecting the compressor torque of a wind-powered combined heat and power unit, characterized in that, Includes the following steps: Fit the compressor speed-torque curves under different slide valve openings; Obtain the actual compressor speed value and determine the speed range in the compressor speed-torque curve where the actual compressor speed value is located, and record it as the current operating speed range; Record the function graph of different compressor slide valve openings within the current speed range; Obtain the actual value of the compressor slide valve opening, and determine the slide valve opening range in which the actual value of the compressor slide valve opening is located in the compressor speed-speed curve, and record it as the current operating slide valve opening range; Determine the function graphs corresponding to the upper and lower limits of the current valve opening range, denoted as the upper limit broken line and the lower limit broken line, respectively. Calculate the slopes of the upper limit broken line and the lower limit broken line, the lower limit value of the current operating speed range, and the torque value corresponding to the lower limit value of the current operating speed range. Establish linear expressions for the upper limit broken line and the lower limit broken line, denoted as the first expression and the second expression, respectively. By combining the first expression, the second expression, and the actual value of the compressor speed, the torque values ​​corresponding to the upper and lower limits of the current operating slide valve opening range are calculated and denoted as the upper limit torque value and the lower limit torque value, respectively. Based on the upper limit torque value and the lower limit torque value, a linear expression for the compressor torque and slide valve opening within the current operating slide valve opening range is established and denoted as the third expression. The actual value of the compressor slide valve opening is substituted into the third expression to obtain the actual compressor torque.

2. The compressor torque detection method for wind power cogeneration units according to claim 1, characterized in that, The steps for fitting the compressor speed-torque curves under different slide valve openings include: Before the compressor is installed in the nacelle, refrigerant is charged into the compressor to simulate the operation process of a wind power cogeneration unit. The compressor speed is adjusted from low to high under different compressor slide valve openings, and the torque at different speeds is measured. Based on the measured compressor speed and torque data, the compressor speed-torque curves under different slide valve openings are fitted using a multi-segment broken line method.

3. The compressor torque detection method for wind power cogeneration units according to claim 1, characterized in that, The main CPU of the wind power cogeneration unit control system reads the wind turbine impeller encoder data, calculates the actual impeller speed, and multiplies the actual impeller speed by the speed ratio of the speed booster box to calculate the actual compressor speed.

4. The compressor torque detection method for wind power cogeneration units according to claim 3, characterized in that, If the calculated actual compressor speed exceeds the rated compressor speed during the process of obtaining the actual compressor speed, then the current actual compressor speed is considered to be the rated compressor speed.

5. The compressor torque detection method for wind power cogeneration units according to claim 1, characterized in that, The main CPU of the wind power cogeneration unit control system reads the signal from the slide valve opening sensor and calculates the actual value of the compressor slide valve opening.

6. The compressor torque detection method for a wind-powered combined heat and power unit according to claim 5, characterized in that, In the process of calculating the actual value of the compressor slide valve opening, if the calculated actual value of the compressor slide valve opening is less than 10%, then the current actual value of the compressor slide valve opening is considered to be 10%. If the calculated actual value of the compressor slide valve opening is greater than 100%, then the current actual value of the compressor slide valve opening is considered to be 100%.

7. The compressor torque detection method for a wind-powered combined heat and power unit according to claim 1, characterized in that, The first expression is Y1 = y 0i j下 + k i j 下 (x―x 0j ); Where Y1 represents the compressor torque at different compressor speeds on the lower limit curve; y 0i j下 This indicates the torque value corresponding to the lower limit value of the current operating speed range on the lower limit curve; k i j下 Indicates the slope of the lower limit line; x 0j This indicates the lower limit of the compressor speed within the current operating speed range; x represents the compressor speed; The second expression is Y2 = y 0i j上 + k i j 上 (x―x 0j ); Y2 represents the compressor torque at different compressor speeds on the upper limit curve; y 0i j上 This indicates the torque value corresponding to the lower limit of the current operating speed range on the upper limit curve. k i j上 This indicates the slope of the upper limit line; x represents the compressor speed; The third expression is Y = Y 下 +(Y 上 -Y 下 (z―z) i ) / (z i+1 ―z i ); Where Y represents the actual torque of the compressor under different compressor slide valve openings at the actual compressor speed; Y 下 Indicates the lower limit torque value; Y 上 Indicates the upper limit torque value; z represents the compressor slide valve opening degree; z i+1 This indicates the upper limit of the current operating spool valve opening range; z i This indicates the lower limit of the current operating spool valve opening range.

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