Reliability evaluation method and system for ORC system

Abstract

The invention provides a reliability evaluation method and system for an ORC (organic Rankine cycle) system, and the method comprises the steps: carrying out the target recognition of pixel points in a heat radiation image, and obtaining the heat radiation images of a condenser, an expansion machine, a working medium pump, an evaporator and the environment temperature; thermodynamic charts of the condenser, the expansion machine, the working medium pump and the evaporator are calculated through the thermal radiation image; calculating enthalpy values of the condenser, the expansion machine, the working medium pump and the evaporator according to the thermodynamic chart; calculating # imgabs0 loss of the condenser, the expansion machine, the working medium pump and the evaporator according to the enthalpy value; according to the method, the thermal radiation images of the ORC system at different environment temperatures can be captured in real time, the # imgabs 2 # loss and the reliability of the system can be dynamically evaluated, the state change of the system in actual operation can be effectively reflected, and the reliability of the ORC system at different environment temperatures can be evaluated. And the accuracy and timeliness of evaluation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ORC systems, and in particular to a reliability assessment method and system for an ORC system. Background Art

[0002] With the continuous growth of energy demand and the increasingly severe environmental problems, the Organic Rankine Cycle (ORC) system, as an efficient heat recovery technology, has been widely used in the fields of industrial waste heat utilization, geothermal power generation, solar power generation, etc. The ORC system uses low-grade heat sources to drive organic working fluids for cyclic power generation, and has the advantages of environmental protection, high efficiency, and strong adaptability. However, the long-term stable operation and reliability of the ORC system directly affect its economic benefits and promotion prospects.

[0003] The ORC system consists of multiple subsystems (such as evaporator, condenser, expander, working fluid pump, etc.), and there are complex interactions and dependencies between the subsystems. Traditional reliability assessment methods are difficult to fully consider these complexities and uncertainties, resulting in a large deviation between the assessment results and the actual operating conditions. Summary of the invention

[0004] To solve the above problems, the present invention aims to provide a reliability assessment method and system for an ORC system.

[0005] A reliability assessment method for an ORC system, comprising:

[0006] Step 1: Obtain thermal radiation images of the ORC system at different ambient temperatures;

[0007] Step 2: Perform target recognition on the pixel points in the thermal radiation image to obtain the thermal radiation images of the condenser, expander, working fluid pump, evaporator and ambient temperature;

[0008] Step 3: Calculate the thermodynamic diagrams of the condenser, expander, working fluid pump and evaporator using the thermal radiation image;

[0009] Step 4: Calculate the enthalpy values ​​of the condenser, expander, working fluid pump and evaporator according to the thermodynamic diagram;

[0010] Step 5: Calculate the enthalpy of the condenser, expander, working fluid pump and evaporator loss;

[0011] Step 6: According to the condenser, expander, working fluid pump and evaporator The reliability of the ORC system is evaluated under different ambient temperatures.

[0012] Preferably, the step 2: performing target recognition on pixel points in the thermal radiation image to obtain thermal radiation images of the condenser, the expander, the working fluid pump, the evaporator and the engine includes:

[0013] Step 2.1: Determine the distance feature and color feature according to the position and color value of the pixel point in the thermal radiation image;

[0014] Step 2.2: Determine the gradient feature according to the gradient value of the pixel point in the thermal radiation image;

[0015] Step 2.3: Determine the foreground features according to the pixel values ​​of the pixels in the thermal radiation image;

[0016] Step 2.4: Calculate the distance value between any pixel point and the cluster center using the distance feature, color feature, gradient feature and foreground feature;

[0017] Step 2.5: Construct a clustering function based on the distance value;

[0018] Step 2.6: Solve the clustering function to obtain thermal radiation images of the condenser, expander, working fluid pump, evaporator and engine.

[0019] Preferably, the step 2.1: determining the distance feature and the color feature according to the position and color value of the pixel point in the thermal radiation image includes:

[0020] The thermal radiation image is converted into the LAB color space, and the distance feature and color feature are determined according to the color value and position of the thermal radiation image in the LAB color space; wherein, the calculation formulas of the distance feature and the color feature are as follows:

[0021]

[0022] Among them, d c (i,k) is the color feature, d s (i,k) is the distance feature, l i is the value of the i-th pixel in the L channel, l k is the value of the kth cluster center in the L channel, a i is the value of the i-th pixel in channel A, a k is the value of the kth cluster center in channel A, b i is the value of the i-th pixel in the B channel, b k is the value of the kth cluster pixel in the B channel, x i is the value of the i-th pixel at the horizontal coordinate, x k is the value of the kth cluster center on the horizontal axis, y i is the value of the i-th pixel at the ordinate, y k is the value of the kth cluster center on the ordinate.

[0023] Preferably, in step 2.2, the gradient feature calculation formula is:

[0024]

[0025] Among them, G xi is the gradient value of the i-th pixel in the x direction, G yi is the gradient value of the i-th pixel in the x direction, G xk is the gradient value of the kth cluster center in the x direction, G xk is the gradient value of the kth cluster center in the x direction, d G (i,k) is the gradient feature.

[0026] Preferably, in step 2.3, the foreground feature is determined based on image morphology:

[0027]

[0028] Among them, e is the structural element, I(x,y) is the thermal radiation image, is the image opening operation, T x is the foreground feature of the x-th point, T i is the foreground feature of the i-th point, T k is the foreground feature of the kth cluster center.

[0029] Preferably, in step 2.5, the clustering function is:

[0030]

[0031] Among them, m c is the color coefficient, s is the distance coefficient, λ1 is the gradient coefficient, λ2 is the foreground coefficient, is pixel x i The membership degree to the k-th cluster center, JD is the clustering function.

[0032] Preferably, the step 3.3: determining the second threshold by using a ranking function comprises:

[0033] According to the working process of the ORC system, the calculation of the condenser, expander, working fluid pump and evaporator loss; among them, the condenser The loss is:

[0034]

[0035] Expander The loss is:

[0036] I c =T0m f[(s2-s1)]

[0037] Working fluid pump The loss is:

[0038] I t =T0m f [(s4-s3)]

[0039] Evaporator The loss is:

[0040]

[0041] Where T0 represents the ambient temperature, m f represents the mass flow rate of the working fluid, s1 represents the specific entropy value of the working fluid vapor during the isentropic expansion process in the expander, s2 represents the specific entropy value of the working fluid during the isobaric condensation process in the condenser, s3 represents the specific entropy value of the working fluid during the isentropic compression process in the working fluid pump, s4 represents the specific entropy value of the working fluid during the isobaric heat absorption process in the evaporator, h1 represents the enthalpy value of the working fluid vapor during the isentropic expansion process in the expander, h2 represents the enthalpy value of the working fluid during the isobaric condensation process in the condenser, h3 represents the enthalpy value of the working fluid during the isentropic compression process in the working fluid pump, and h4 represents the enthalpy value of the working fluid during the isobaric heat absorption process in the evaporator.

[0042] The present invention also provides a reliability assessment system for an ORC system, comprising:

[0043] An image acquisition module is used to acquire thermal radiation images of the ORC system at different ambient temperatures;

[0044] An image segmentation module is used to identify the pixels in the thermal radiation image to obtain thermal radiation images of the condenser, expander, working fluid pump, evaporator and ambient temperature;

[0045] Thermodynamic diagram building module for calculating thermodynamic diagrams of condensers, expanders, working fluid pumps and evaporators using thermal radiation images;

[0046] Enthalpy calculation module, used to calculate the enthalpy of the condenser, expander, working fluid pump and evaporator according to thermodynamic diagrams;

[0047] The loss calculation module is used to calculate the loss of condensers, expanders, working fluid pumps and evaporators based on enthalpy values. loss;

[0048] Reliability evaluation module for condensers, expanders, working fluid pumps and evaporators The reliability of the ORC system is evaluated under different ambient temperatures.

[0049] The present invention also provides an electronic device, comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, and wherein the computer program, when executed by the processor, implements the steps in the above-mentioned reliability assessment method for an ORC system.

[0050] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps in the above-mentioned reliability assessment method for an ORC system when executed by a processor.

[0051] The reliability evaluation method and system for an ORC system provided by the present invention have the following beneficial effects: compared with the prior art, the present invention can capture the thermal radiation image of the ORC system at different ambient temperatures in real time and dynamically evaluate the reliability of the system. Loss and reliability can effectively reflect the state changes of the system in actual operation and improve the accuracy and timeliness of the evaluation.

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 A flow chart of a reliability assessment method for an ORC system provided by an embodiment of the present invention is shown;

[0055] Figure 2 The figure shows the working principle diagram of the ORC system provided by the embodiment of the present invention. DETAILED DESCRIPTION

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0057] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] See also Figure 1-2 , a reliability assessment method for an ORC system, comprising:

[0060] Step 1: Acquire thermal radiation images of the ORC system at different ambient temperatures; in the embodiment of the present invention, the thermal radiation image is an infrared image.

[0061] Step 2: Perform target recognition on the pixel points in the thermal radiation image to obtain the thermal radiation images of the condenser, expander, working fluid pump, evaporator and ambient temperature;

[0062] Furthermore, the step 2 comprises:

[0063] Step 2.1: Determine the distance feature and color feature according to the position and color value of the pixel points in the thermal radiation image;

[0064] In step 2, the thermal radiation image is converted into the LAB color space, and the distance feature and the color feature are determined according to the color value and position of the thermal radiation image in the LAB color space; wherein the calculation formulas of the distance feature and the color feature are as follows:

[0065]

[0066] Among them, d c (i,k) is the color feature, d s (i,k) is the distance feature, l i is the value of the i-th pixel in the L channel, l k is the value of the kth cluster center in the L channel, a i is the value of the i-th pixel in channel A, a k is the value of the kth cluster center in channel A, b i is the value of the i-th pixel in the B channel, b k is the value of the kth cluster pixel in the B channel, x i is the value of the i-th pixel at the horizontal coordinate, x k is the value of the kth cluster center on the horizontal axis, y i is the value of the i-th pixel at the ordinate, y k is the value of the kth cluster center on the ordinate.

[0067] Step 2.2: Determine the gradient feature according to the gradient value of the pixel point in the thermal radiation image;

[0068] When the colors of adjacent pixels are very close, it is difficult to distinguish the edge contours between pixels by color, resulting in loss of edge information. In order to find a contour line that can distinguish pixels, the present invention introduces a gradient feature.

[0069] In step 2.2, the gradient feature calculation formula is:

[0070]

[0071] Among them, G xi is the gradient value of the i-th pixel in the x direction, G yi is the gradient value of the i-th pixel in the x direction, G xk is the gradient value of the kth cluster center in the x direction, G xk is the gradient value of the kth cluster center in the x direction, d G (i,k) is the gradient feature.

[0072] Step 2.3: Determine the foreground features according to the pixel values ​​of the pixels in the thermal radiation image;

[0073] In step 2.3, the foreground features are determined based on image morphology:

[0074]

[0075] Among them, e is the structural element, I(x,y) is the thermal radiation image, is the image opening operation, Tx is the foreground feature of the x-th point, T i is the foreground feature of the i-th point, T k is the foreground feature of the kth cluster center.

[0076] Step 2.4: Calculate the distance value between any pixel point and the cluster center using the distance feature, color feature, gradient feature and foreground feature;

[0077] Step 2.5: Construct a clustering function based on the distance value;

[0078] In step 2.5, the clustering function is:

[0079]

[0080] Among them, m c is the color coefficient, s is the distance coefficient, λ1 is the gradient coefficient, λ2 is the foreground coefficient, is pixel x i The membership degree to the k-th cluster center, JD is the clustering function.

[0081] Step 2.6: Solve the clustering function to obtain thermal radiation images of the condenser, expander, working fluid pump, evaporator and engine.

[0082] Since the traditional clustering function is constructed based on the Euclidean distance, when measuring the differences between samples, it can only be determined by the Euclidean distance between different samples. However, the present invention constructs a clustering function based on the characteristic distance between the pixel point and the cluster center, which can expand the differences between each cluster sample from four aspects, making the clustering result more reliable.

[0083] Step 3: Calculate the thermodynamic diagrams of the condenser, expander, working fluid pump and evaporator using the thermal radiation image;

[0084] Step 4: Calculate the enthalpy values ​​of the condenser, expander, working fluid pump and evaporator according to the thermodynamic diagram;

[0085] Step 5: Calculate the enthalpy of the condenser, expander, working fluid pump and evaporator loss;

[0086] In step 5, the heat dissipation of the condenser, expander, working fluid pump and evaporator is calculated according to the working process of the ORC system. loss; among them, the condenser The loss is:

[0087]

[0088] Expander The loss is:

[0089] I c =T0m f [(s2-s1)]

[0090] Working fluid pump The loss is:

[0091] I t =T0m f [(s4-s3)]

[0092] Evaporator The loss is:

[0093]

[0094] Where T0 represents the ambient temperature, m f represents the mass flow rate of the working fluid, s1 represents the specific entropy value of the working fluid vapor during the isentropic expansion process in the expander, s2 represents the specific entropy value of the working fluid during the isobaric condensation process in the condenser, s3 represents the specific entropy value of the working fluid during the isentropic compression process in the working fluid pump, s4 represents the specific entropy value of the working fluid during the isobaric heat absorption process in the evaporator, h1 represents the enthalpy value of the working fluid vapor during the isentropic expansion process in the expander, h2 represents the enthalpy value of the working fluid during the isobaric condensation process in the condenser, h3 represents the enthalpy value of the working fluid during the isentropic compression process in the working fluid pump, and h4 represents the enthalpy value of the working fluid during the isobaric heat absorption process in the evaporator.

[0095] Step 6: According to the condenser, expander, working fluid pump and evaporator The reliability of the ORC system is evaluated under different ambient temperatures.

[0096] In practical applications, the evaporator The loss mainly comes from the irreversibility of heat transfer between the working fluid and the heat source. The losses mainly come from mechanical friction and flow loss. The loss mainly comes from the irreversibility of heat transfer between the working fluid and the environment. The loss mainly comes from mechanical friction and irreversibility during compression. Therefore, the present invention requires that each component The losses are added together to get the total loss of the entire ORC system. The loss is used as an indicator of reliability to analyze the total The reliability of the ORC system is evaluated by analyzing the variation trend of the loss with the ambient temperature.

[0097] The present invention can capture the thermal radiation images of the ORC system at different ambient temperatures in real time and dynamically evaluate the system's Loss and reliability can effectively reflect the state changes of the system in actual operation and improve the accuracy and timeliness of the evaluation.

[0098] The present invention also provides a reliability assessment system for an ORC system, comprising:

[0099] An image acquisition module is used to acquire thermal radiation images of the ORC system at different ambient temperatures;

[0100] An image segmentation module is used to identify the pixels in the thermal radiation image to obtain thermal radiation images of the condenser, expander, working fluid pump, evaporator and ambient temperature;

[0101] Thermodynamic diagram building module for calculating thermodynamic diagrams of condensers, expanders, working fluid pumps and evaporators using thermal radiation images;

[0102] Enthalpy calculation module, used to calculate the enthalpy of the condenser, expander, working fluid pump and evaporator according to thermodynamic diagrams;

[0103] The loss calculation module is used to calculate the loss of condensers, expanders, working fluid pumps and evaporators based on enthalpy values. loss;

[0104] Reliability evaluation module for condensers, expanders, working fluid pumps and evaporators The reliability of the ORC system is evaluated under different ambient temperatures.

[0105] The present invention also provides an electronic device, comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, and wherein the computer program, when executed by the processor, implements the steps in the above-mentioned reliability assessment method for an ORC system.

[0106] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps in the above-mentioned reliability assessment method for an ORC system when executed by a processor.

[0107] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A reliability assessment method for an ORC system, characterized in that: include: Step 1: Obtain thermal radiation images of the ORC system at different ambient temperatures; Step 2: Perform target recognition on the pixel points in the thermal radiation image to obtain the thermal radiation images of the condenser, expander, working fluid pump, evaporator and ambient temperature; Step 3: Calculate the thermodynamic diagrams of the condenser, expander, working fluid pump and evaporator using the thermal radiation image; Step 4: Calculate the enthalpy values ​​of the condenser, expander, working fluid pump and evaporator according to the thermodynamic diagram; Step 5: Calculate the enthalpy of the condenser, expander, working fluid pump and evaporator loss; Step 6: According to the condenser, expander, working fluid pump and evaporator The reliability of the ORC system is evaluated under different ambient temperatures.

2. A reliability assessment method for an ORC system according to claim 1, characterized in that: The step 2: performing target recognition on the pixel points in the thermal radiation image to obtain the thermal radiation images of the condenser, the expander, the working fluid pump, the evaporator and the engine, includes: Step 2.1: Determine the distance feature and color feature according to the position and color value of the pixel points in the thermal radiation image; Step 2.2: Determine the gradient feature according to the gradient value of the pixel point in the thermal radiation image; Step 2.3: Determine the foreground features according to the pixel values ​​of the pixels in the thermal radiation image; Step 2.4: Calculate the distance value between any pixel point and the cluster center using the distance feature, color feature, gradient feature and foreground feature; Step 2.5: Construct a clustering function based on the distance value; Step 2.6: Solve the clustering function to obtain thermal radiation images of the condenser, expander, working fluid pump, evaporator and engine.

3. A reliability assessment method for an ORC system according to claim 2, characterized in that: The step 2.1: determining the distance feature and the color feature according to the position and color value of the pixel point in the thermal radiation image, comprises: The thermal radiation image is converted into the LAB color space, and the distance feature and color feature are determined according to the color value and position of the thermal radiation image in the LAB color space; wherein, the calculation formulas of the distance feature and the color feature are as follows: Among them, d c (i,k) is the color feature, d s (i,k) is the distance feature, l i is the value of the i-th pixel in the L channel, l k is the value of the kth cluster center in the L channel, a i is the value of the i-th pixel in channel A, a k is the value of the kth cluster center in channel A, b i is the value of the i-th pixel in the B channel, b k is the value of the kth cluster pixel in the B channel, x i is the value of the i-th pixel at the horizontal coordinate, x k is the value of the kth cluster center on the horizontal axis, y i is the value of the i-th pixel at the ordinate, y k is the value of the kth cluster center on the ordinate.

4. A reliability assessment method for an ORC system according to claim 3, characterized in that: In step 2.2, the gradient feature calculation formula is: Among them, G xi is the gradient value of the i-th pixel in the x direction, G yi is the gradient value of the i-th pixel in the x direction, G xk is the gradient value of the kth cluster center in the x direction, G xk is the gradient value of the kth cluster center in the x direction, d G (i,k) is the gradient feature.

5. A reliability assessment method for an ORC system according to claim 4, characterized in that: In step 2.3, the foreground features are determined based on image morphology: Among them, e is the structural element, I(x,y) is the thermal radiation image, is the image opening operation, T x is the foreground feature of the x-th point, T i is the foreground feature of the i-th point, T k is the foreground feature of the kth cluster center.

6. A reliability assessment method for an ORC system according to claim 5, characterized in that: In step 2.5, the clustering function is: Among them, m c is the color coefficient, s is the distance coefficient, λ1 is the gradient coefficient, λ2 is the foreground coefficient, is pixel x i The membership degree to the k-th cluster center, JD is the clustering function.

7. A reliability assessment method for an ORC system according to claim 6, characterized in that: Step 5: Calculate the enthalpy of the condenser, expander, working fluid pump and evaporator according to the enthalpy value Losses, including: According to the working process of the ORC system, the calculation of the condenser, expander, working fluid pump and evaporator loss; among them, the condenser The loss is: Expander The loss is: I c =T0m f [(s2-s1)] Working fluid pump The loss is: IN t =T0m f [(s4-s3)] Evaporator The loss is: Where T0 represents the ambient temperature, m f represents the mass flow rate of the working fluid, s1 represents the specific entropy value of the working fluid vapor during the isentropic expansion process in the expander, s2 represents the specific entropy value of the working fluid during the isobaric condensation process in the condenser, s3 represents the specific entropy value of the working fluid during the isentropic compression process in the working fluid pump, s4 represents the specific entropy value of the working fluid during the isobaric heat absorption process in the evaporator, h1 represents the enthalpy value of the working fluid vapor during the isentropic expansion process in the expander, h2 represents the enthalpy value of the working fluid during the isobaric condensation process in the condenser, h3 represents the enthalpy value of the working fluid during the isentropic compression process in the working fluid pump, and h4 represents the enthalpy value of the working fluid during the isobaric heat absorption process in the evaporator.

8. A reliability assessment system for an ORC system, characterized in that: include: An image acquisition module is used to acquire thermal radiation images of the ORC system at different ambient temperatures; An image segmentation module is used to identify the pixels in the thermal radiation image to obtain thermal radiation images of the condenser, expander, working fluid pump, evaporator and ambient temperature; Thermodynamic diagram building module for calculating thermodynamic diagrams of condensers, expanders, working fluid pumps and evaporators using thermal radiation images; Enthalpy calculation module, used to calculate the enthalpy of the condenser, expander, working fluid pump and evaporator according to thermodynamic diagrams; The loss calculation module is used to calculate the loss of condensers, expanders, working fluid pumps and evaporators based on enthalpy values. loss; Reliability evaluation module for condensers, expanders, working fluid pumps and evaporators The reliability of the ORC system is evaluated under different ambient temperatures.

9. An electronic device, comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, wherein: When the computer program is executed by the processor, the steps of a reliability assessment method for an ORC system according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a reliability assessment method for an ORC system according to any one of claims 1 to 7 are implemented.

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