JP4413812B2 - Abnormality detection device in power generation system - Google Patents

Description

  The present invention relates to an abnormality detection device that detects the occurrence of an abnormality in a stationary engine used in a power generation system.

2. Description of the Related Art Conventionally, as a power generation system, a technology is known in which a stationary type stationary engine such as a gas engine or a diesel engine is operated and power is generated using a driving force generated by this operation.
In any cylinder of the stationary engine, for example, if an abnormality such as seizure occurs on a piston or a connecting rod, the stationary engine may be broken (damaged). It is necessary to stop it before it occurs.

  Therefore, for example, in the burn-in prediction device for an internal combustion engine disclosed in Patent Document 1, a vibration sensor is attached to a cylinder block of the internal combustion engine, and output data of the vibration sensor is taken out for each explosion stroke of each cylinder. In the comparator, it is determined whether or not the amount of decrease in vibration data of each cylinder exceeds a reference value, and a cylinder in a state just before the piston is burned is determined. Thereby, the sign is detected well before actual occurrence of seizure, and seizure, which is a serious failure, is prevented in advance.

  Further, for example, in the piston ring sticking monitoring device of the reciprocating engine disclosed in Patent Document 2, temperatures for detecting the wall surface temperature of the cylinder liner at a plurality of locations in the circumferential direction of the cylinder liner that accommodates the piston so as to reciprocate. Each measuring end is attached. And in the calculator, the circumferential displacement of the piston ring in the piston is detected from the temperature distribution at the plurality of temperature measurement ends. As a result, the adhesion of the piston ring is monitored, and seizure of the piston ring to the cylinder liner is prevented in advance.

However, in the conventional apparatus for performing abnormality detection, it is necessary to separately attach the vibration sensor or the temperature measurement end in the engine, which complicates the apparatus. Further, it has not been sufficient to detect an abnormality quickly with high detection accuracy by a device having a simple configuration.
Furthermore, there is no disclosure of a technique regarding an abnormality detection device that is effective when a power generation system is configured using an engine.

JP-A-6-137163 JP-A-6-346789

  The present invention has been made in view of such conventional problems, and an attempt is made to provide an abnormality detection device capable of quickly detecting an abnormality occurring in a stationary engine with high detection accuracy by a simple device configuration. To do.

The first invention is an abnormality detection device for detecting an abnormality in the stationary engine, which is used in a power generation system that operates a generator by the output of the stationary engine.
The abnormality detection device sequentially measures the pressure of the fuel mixture supplied to the stationary engine and the power generation output of the generator, and sequentially stores the measured pressure and power generation output as pressure data and power generation output data. Configured to
The time point at which the measurement is performed is set as a determination time point, and the time point at which the measurement is performed immediately before the determination time point is a past time point. The pressure change rate of the pressure data at the determination time point relative to the pressure data at the past time point An assumed value calculation step for calculating a power generation output assumed value at the determination time from a relationship with the power generation output assumed value at the past time;
When the determination data calculated based on the ratio or difference between the power generation output data at the determination time and the power generation output estimated value at the determination time is out of a predetermined reference range, an abnormality has occurred in the stationary engine. An abnormality detecting device in a power generation system is characterized in that the abnormality determining step for detecting this is repeated every time the measurement is performed.

The abnormality detection device of the present invention is used in a power generation system, and detects an abnormality in a stationary engine using the pressure of a fuel mixture supplied to the stationary engine and the power generation output of the generator.
By the way, the power generation output of the generator is closely related to the pressure of the fuel mixture in the stationary engine, and if the pressure of the fuel mixture increases, the power generation output of the generator tends to increase. If the air pressure decreases, the power generation output of the generator tends to decrease.
In the present invention, the fuel mixture refers to a mixture of fuel and air.

In the present invention, by utilizing the correlation between the pressure of the fuel mixture and the power generation output of the generator, the pressure data as the pressure of the fuel mixture and the power generation output actually generated in the generator The occurrence of an abnormality in the stationary engine is detected by monitoring the generated power output data.
Specifically, when monitoring the presence or absence of an abnormality in a stationary engine, the abnormality detection device sequentially measures the pressure and power generation output of the fuel mixture, and uses the pressure and power generation output thus measured as pressure data. And it stores sequentially as power generation output data.

Then, the abnormality detection apparatus repeatedly performs the assumed value calculation step and the abnormality determination step each time the measurement is performed.
That is, in the assumed value calculation step, the abnormality detection device calculates the pressure change rate of the pressure data at the determination time with respect to the pressure data at the past time, and from the relationship between the pressure change rate and the power generation output assumed value at the past time, A power generation output assumption value at the time of determination is calculated.

  Further, in the assumed value calculation step, at the time of the first determination time, the pressure data at the past time is the pressure data at the start of the abnormality diagnosis, and the estimated power generation output value at the past time is the value at the time of the abnormality diagnosis start. Use power generation output data. In the second and subsequent determination time points, the past time point is sequentially updated so that the measurement is performed one time before the determination time point. The pressure data measured immediately before the determination time point is used, and the estimated power generation output value at the past time point is the power generation output estimated value calculated one time before each determination time after the second time.

  Next, in the abnormality determination step, the abnormality detection device determines whether or not the determination data based on the power generation output data at the determination time and the power generation output assumed value at the determination time is within a predetermined reference range. Then, the abnormality detection device detects that an abnormality has occurred in the stationary engine when the determination data is out of the predetermined reference range.

  Here, when the stationary engine is operating normally, when the pressure of the fuel mixture increases, the power generation output also increases, or the pressure of the fuel mixture decreases. When the direction changes, it is estimated that the power generation output also changes in a decreasing direction. At this time, the determination data in the abnormality determination step is maintained within the predetermined reference range.

  On the other hand, when an abnormality such as seizure occurs in the stationary engine, the power generation output of the generator decreases or does not increase so much due to an increase in loss in the stationary engine. At this time, since the power generation output of the generator does not reach a predetermined target power generation output, the pressure of the fuel mixture is greatly increased. Therefore, at this time, the determination data in the abnormality determination step is out of the predetermined reference range, and the abnormality detection device can detect that an abnormality has occurred in the stationary engine.

As described above, in the present invention, the relative change of each state quantity is monitored as the change of the pressure of the fuel mixture and the change of the power generation output using the correlation between the pressure of the fuel mixture and the power generation output. Thus, it is possible to detect whether an abnormality has occurred in the stationary engine.
Therefore, for example, even when there is a difference in the absolute value as the value of the power generation output with respect to the pressure value of the fuel mixture due to a change in engine characteristics with time or the like, the abnormality can be detected accurately and quickly.

The measurement of the pressure of the fuel mixture and the measurement of the power generation output of the generator can be performed using a pressure measurement means and a power generation output measurement means used for controlling or monitoring the power generation system. Therefore, it is not necessary to separately provide a sensor (measurement means) as special hardware in order to perform the abnormality detection, and the configuration of the abnormality detection device can be simplified.
Therefore, according to the abnormality detection device of the present invention, an abnormality occurring in the stationary engine can be quickly detected with high detection accuracy by a simple device configuration.

The second invention is an abnormality detection device for detecting an abnormality in the stationary engine, which is used in a power generation system that operates a generator by the output of the stationary engine.
The abnormality detection device sequentially measures the flow rate of fuel supplied to the stationary engine and the power generation output of the generator, and sequentially stores the measured flow rate and power generation output as flow rate data and power generation output data. Configured,
The time point at which the measurement is performed is set as a determination time point, and the time point at which the measurement is performed immediately before the determination time point is a past time point. The flow rate change rate of the flow rate data at the determination time point with respect to the flow rate data at the past time point An assumed value calculation step for calculating a power generation output assumed value at the determination time from a relationship with the power generation output assumed value at the past time;
When the determination data calculated based on the ratio or difference between the power generation output data at the determination time and the power generation output estimated value at the determination time is out of a predetermined reference range, an abnormality occurs in the stationary engine. An abnormality detecting device in a power generation system, wherein the abnormality determining step for detecting the occurrence of the abnormality is configured to be repeated every time the measurement is performed.

The abnormality detection device of the present invention measures the flow rate (flow velocity) of the fuel instead of measuring the pressure of the fuel mixture in the first invention, and uses the flow rate data instead of the pressure data. An abnormality in a stationary engine is detected.
Also in the abnormality detection device of the present invention, the other configuration is the same as that of the first invention, and an abnormality occurring in the stationary engine can be detected quickly with high detection accuracy by a simple device configuration.

A preferred embodiment in the first and second inventions described above will be described.
In the first aspect, the stationary engine may be a gas engine that operates using a gas fuel such as city gas or natural gas. Further, the first invention is preferably applied when the gas engine is operated with almost no change in the mixing ratio (air ratio) of the gas fuel and air.

  In the second aspect, the stationary engine can be a gas engine or a diesel engine that operates using light oil as the fuel. In this case, even when the mixing ratio of fuel and air (air ratio) changes, the flow rate of the fuel is measured, and the detected flow rate is used as the flow rate data to detect the abnormality. It can be performed with high accuracy.

  In the first and second aspects of the invention, the power generation system may be a dedicated power generation system that performs only power generation in the generator using the output of the stationary engine. In addition, the power generation system uses the output of the stationary engine to generate power in the generator, and uses the exhaust heat of the cooling water and exhaust gas from the operation of the stationary engine for the air conditioner or water heater, etc. It can also be.

Further, the generator preferably generates power at a constant rotational speed. In particular, this generator is preferably configured to generate power in conjunction with a commercial power system.
The stationary engine refers to an engine that is installed and used in a factory, a building, a house, or the like.

Further, the predetermined reference range can be set as a variation range of the determination data when the stationary engine is normally operated.
The pressure change rate can be calculated based on the ratio or difference of the pressure data at the determination time with respect to the pressure data at the past time.

  Examples of the abnormality in the stationary engine that can be detected by the abnormality detection device include a mechanical abnormality such as an abnormality due to piston ring seizure or wear and an abnormality due to connecting rod seizure or wear. Further, for example, it is considered possible to detect a misfire abnormality in a cylinder (cylinder) of a stationary engine, an abnormality in blowout of combustion gas in the cylinder (an abnormality that occurs when the exhaust valve in the cylinder does not close), and the like.

  In the first aspect of the invention, the abnormality detection device is configured to sequentially measure the temperature of the fuel mixture, and to store the measured temperature sequentially as temperature data. In the step, it is preferable that the pressure change rate is corrected by a temperature change rate of the temperature data at the determination time with respect to the temperature data at the past time.

By the way, the pressure of the fuel mixture also changes as the temperature of the fuel mixture changes. Therefore, it is possible to further improve the detection accuracy of occurrence of abnormality in the stationary engine by correcting the pressure change rate of the fuel mixture based on the temperature change rate.
The temperature change rate can be calculated based on the ratio or difference of the temperature data at the determination time with respect to the temperature data at the past time.

In the first and second aspects of the invention, the abnormality detection device detects an abnormality in the stationary engine when the determination data continues out of the predetermined reference range for a predetermined number of times in the abnormality determination step. It is preferable to be configured to detect the occurrence of the above (claim 4).
By the way, in order to detect the occurrence of abnormality in the stationary engine sensitively, it is conceivable to narrow the predetermined reference range as narrow as possible. On the other hand, if the predetermined reference range is narrowed down to a narrow range, there is a possibility that the abnormality is erroneously detected even though no abnormality has occurred. Therefore, when the abnormality detection device repeatedly performs the assumed value calculation step and the abnormality determination step, the abnormality is detected for the first time when the determination data is out of the predetermined reference range for a predetermined number of times. The detection accuracy of the detection device can be further increased, and the occurrence of abnormality can be detected more rapidly.
The predetermined number of times can be set to 2 to 10 times, for example.

  Further, the abnormality detection device repeats the assumed value calculation step and the abnormality determination step a predetermined number of times, and the determination data deviates from the predetermined reference number within the predetermined reference number during the predetermined number of times. If not, the power generation output data at the determination time point corresponding to the predetermined number of times is replaced with the power generation output assumed value at the determination time point, while the determination data is within the predetermined reference range during the predetermined number of times. It is preferable that the above replacement is not performed when the inside deviates more than the reference number of times (claim 5).

The configuration in this case is an effective configuration in an abnormality detection device having a configuration that detects the occurrence of the abnormality when the determination data is out of the predetermined reference range for a predetermined number of times in the abnormality determination step. It is.
That is, when monitoring the presence or absence of an abnormality in the stationary engine using the abnormality detection device, the determination data is within the predetermined reference range in the abnormality determination step while the steps are performed a predetermined number of times. When the predetermined reference number is not deviated, it is estimated that there is a low possibility that an abnormality will occur in the stationary engine. Therefore, at this time, the power generation output data at the determination point corresponding to the predetermined number of times is replaced with the power generation output assumption value at the determination point (substituting the power generation output data into the power generation output assumption value).

  And when performing each said step after the said determination time, the electric power generation output data in the said determination time is used as an electric power generation output assumption value in the past time in the next determination time. As a result, there is a large difference between the estimated power generation output value that is a theoretical value and the power generation output data obtained by actually performing the measurement due to accumulated errors that occur each time the abnormality detection device repeats the above steps. It is possible to prevent the difference from occurring.

  On the other hand, if the determination data falls outside the predetermined reference range by a predetermined reference number or more in the abnormality determination step while the above steps are performed a predetermined number of times, there is a possibility that an abnormality may occur in the stationary engine. Presumed to be expensive. Therefore, at this time, when the above steps are performed after the determination time without performing the replacement, the estimated power generation output value at the determination time is changed to the next determination time as in the case before the determination time. It is used as an estimated power generation output at the past time.

Then, when it is estimated that the abnormality is likely to occur, the difference generated between the power generation output expected value and the power generation output data is maintained, and the determination data is again determined in the abnormality determination step. It is easy to get out of the standard range. Thereby, when it is estimated that the above-described abnormality is likely to occur, the sensitivity of detecting the abnormality can be improved.
Therefore, the detection accuracy of the abnormality detection device can be further enhanced by the configuration using the replacement. Note that the predetermined reference number can be, for example, 1 to 3 times.

Hereinafter, embodiments of the abnormality detection device in the power generation system of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the abnormality detection device 7 of this example is used for a power generation system 1 that operates a generator 3 by the output of a stationary engine 2, and detects an abnormality in the stationary engine 2. Is.
The abnormality detection device 7 sequentially measures the pressure of the fuel mixture G3 supplied to the stationary engine 2 and the power generation output of the generator 3, and uses the pressure and power generation output thus measured as pressure data P (i) and The power generation output data W (i) is sequentially stored.

And the abnormality detection apparatus 7 is comprised so that the following taking-in steps, an assumed value calculation step, and an abnormality determination step may be performed repeatedly.
That is, as shown in FIG. 3, the abnormality detection device 7 captures the pressure data P (i) and the power generation output data W (i) in the capture step.
Next, in the assumed value calculation step, the abnormality detection device 7 sets the current time point when the above measurement is performed as a determination time point and the time point when the measurement is performed immediately before this determination time point as a past time point. Then, the abnormality detection device 7 determines the pressure change rate P (i) / P (i-1) of the pressure data P (i) at the determination time with respect to the pressure data P (i-1) at the past time, and the power generation at the past time. From the relationship with the estimated output value Ws (i−1), the estimated power generation output value Ws (i) at the time of determination is calculated.

Next, in the abnormality determination step, the abnormality detection device 7 determines the determination data X calculated based on the ratio or difference between the power generation output data W (i) at the determination time and the power generation output expected value Ws (i) at the determination time. It is determined whether (i) is out of the predetermined reference range A.
Then, the abnormality detection device 7 repeats the above steps, and detects that an abnormality has occurred in the stationary engine 2 when the determination data X (i) is out of the predetermined reference range A in the abnormality determination step. To do.

Below, it explains in full detail about the abnormality detection apparatus 7 in the electric power generation system 1 of this example.
As shown in FIG. 1, the stationary engine 2 of this example is a gas engine that operates using gas fuel G1 such as city gas (13A). In this gas engine, the gas fuel G1 and the air G2 are combined. Operation is performed with almost no change in the mixing ratio (air ratio).

The stationary engine 2 has a plurality of cylinders 21, and the intake ports of the plurality of cylinders 21 are connected to an intake manifold 4 for supplying a fuel mixture G 3 to each cylinder 21. The intake manifold 4 is provided with pressure measuring means (pressure gauge) 51 for measuring the pressure in the intake manifold 4 and temperature measuring means (thermometer) 52 for measuring the temperature in the intake manifold 4. ing.
Further, the generator 3 is provided with a power generation output measuring means 53 (wattmeter) for measuring the power generation output generated by the power generator 3.

  Further, the abnormality detection device 7 of the present example is configured to sequentially measure the temperature of the fuel mixture G3 and to store the measured temperature as temperature data T (i). Then, the abnormality detecting device 7 also captures the temperature data T (i) in the capturing step, and the pressure change rate P (i) / P (i−1) in the past is calculated in the assumed value calculating step. The temperature data T (i−1) is corrected by the temperature change rate T (i−1) / T (i) of the temperature data T (i) at the determination time with respect to the temperature data T (i−1) at the time.

The pressure data P (i) represents the pressure in the intake manifold 4 measured by the pressure measuring means 51, and the temperature data T (i) is in the intake manifold 4 measured by the temperature measuring means 52. This represents the temperature of the fuel mixture G3.
The power generation output data W (i) represents the power generation output of the generator 3 measured by the power generation output measuring means 53.

Further, as shown in FIG. 1, in the intake system 40, the mixture of the gas fuel G1 and the air G2 is located upstream of the position where the pressure measuring means 51 and the temperature measuring means 52 are arranged in the flow of the fuel mixture G3. A mixer 41 for performing the above is provided. Further, in the intake system 40, the flow rate of the fuel mixture G3 to each cylinder 21 is adjusted between the position where the pressure measuring means 51 and the temperature measuring means 52 are disposed and the position where the mixer 41 is disposed. A governor 43 is provided.
Further, in the intake system 40, the supercharger 42 that operates using the energy of the exhaust gas G4 exhausted from each cylinder 21 and the fuel mixture G3 that has passed through the supercharger 42 and has reached a high temperature are cooled. An intake air cooler 44 is provided for this purpose.
The intake manifold 4 connects a plurality of cylinders 21 and an intake cooler 44.

  The power generation system 1 also includes a control device 6 that performs various controls of the stationary engine 2 and the generator 3. The control device 6 is configured to control the opening degree of the governor 43 so that the power generation output of the generator 3 becomes the target target power generation output. The abnormality detection device 7 is configured in the control device 6. Each step performed by the abnormality detection device 7 is configured by a computer program or the like formed in a hardware circuit in the control device 6.

  Further, the power generation system 1 of this example is of a grid connection type that operates the generator 3 by connection with a commercial power source. This power generation system 1 rotates the generator 3 according to the frequency (50 Hz or 60 Hz) of a commercial power source. The generator 3 generates power by rotating the rotor at a constant rotational speed determined by the frequency of the commercial power source.

The abnormality detection device 7 is configured to sequentially perform the above steps at predetermined time intervals. That is, the abnormality detection device 7 of this example performs the above steps for each determination time point when the power generation output data W (i), the pressure data P (i), and the temperature data T (i) are taken. It is configured as follows.
In addition, the time interval at which the abnormality detecting device 7 of the present example executes the above steps is the same as the sampling interval at which each measuring means performs the measurement.
Further, when the abnormality detection device 7 repeatedly performs the above steps, in the assumed value calculation step, the past time point is determined as the determination time point when each step (abnormality determination) is performed immediately before the determination time point (previous time). It is configured to update sequentially.

The estimated power generation output value Ws (i) of this example is calculated on the assumption that the pressure of the fuel mixture G3 and the power generation output are in a proportional relationship. Further, in order to consider the influence of the temperature of the fuel mixture G3 on the pressure of the fuel mixture G3, it is assumed that the pressure and temperature of the fuel mixture G3 are in an inversely proportional relationship, and the estimated power generation output value Ws ( i) is calculated.
More specifically, PV = GRT (equal gas equation of state, P: pressure of fuel mixture G3, V: volume of intake manifold 4, G: molar amount of fuel mixture G3, R: gas constant, T: Based on the temperature of the fuel mixture G3), a power generation output estimated value Ws (i) is calculated. That is, since V and R are constant, V = {G (i) × T (i)} / P (i) = {G (i−1) × T (i−1)} / P (i−1). Thus, a relational expression of G (i) / G (i−1) = {P (i) / P (i−1)} × {T (i−1) / T (i)} is obtained.

Then, the estimated power generation output value Ws (i) at the determination time is equal to the estimated power generation output value Ws (i−1) at the past time point, and the molar amount increase ratio G (i) / G (i−1) of the fuel mixture. That is, as a value obtained by multiplying the pressure change rate P (i) / P (i-1) and the temperature change rate T (i-1) / T (i), Ws (i) = Ws (i-1) × { P (i) / P (i−1)} × {T (i−1) / T (i)} is calculated from the assumed value calculation relational expression. Here, pressure data P (i) and P (i-1) used in the assumed value calculation relational expression are absolute pressures, and temperature data T (i) and T (i-1) are absolute temperatures.
The determination data X (i) is calculated from a determination relational expression of X = {Ws (i) −W (i)} / W (i). Note that (i) indicates a determination time point, and (i-1) indicates a past time point (previous determination time point).

Further, when the abnormality detection device 7 repeatedly performs each of the above steps, the determination data X (i) continues in the abnormality determination step for a predetermined number of times (in this example, 5 times) or more. It is configured to detect that an abnormality has occurred in the stationary engine 2 when it is out of A.
In addition, each time the above steps are performed a predetermined number of times, the abnormality detection device 7 determines whether or not to replace the power generation output data W (i) at the determination time with the power generation output expected value Ws (i) at the determination time ( It is configured to determine whether or not the power generation output data W (i) is substituted for the power generation output expected value Ws (i).

  In other words, the abnormality detection device 7 does not deviate from the predetermined reference range A within the predetermined reference range A (determined once in this example) while the determination data X (i) is performed a predetermined number of times. The power generation output data W (i) at the determination time corresponding to the predetermined number of times is replaced with the power generation output expected value Ws (i) at the determination time. In addition, the abnormality detection device 7 does not perform the replacement when the determination data X (i) deviates from the predetermined reference range A by the reference number (one time) or more while each step is performed a predetermined number of times. It is configured.

Next, a method for detecting an abnormality in the stationary engine 2 using the abnormality detection device 7 will be described with reference to FIGS.
When detecting the abnormality, first, the stationary engine 2 is operated, and the generator 3 is operated by this output. At this time, the control device 6 controls the opening degree of the governor 43 so that the power generation output of the generator 3 becomes a predetermined target power generation output.

Next, as shown in FIG. 2, the power generation output measuring means 53 measures the power generation output W0 of the generator 3 (step S101), and this power generation output becomes the abnormality diagnosis start power generation output Wr for starting the abnormality diagnosis. It is determined whether or not (S102).
When the power generation output becomes the abnormality diagnosis start power generation output Wr, abnormality diagnosis by the abnormality detection device 7 is started, and the pressure measuring means 51 measures the pressure of the fuel mixture G3 in the intake manifold 4 and The temperature of the fuel mixture G3 in the intake manifold 4 is measured by the temperature measuring means 52 (S103). Further, the pressure and temperature at which this measurement is performed are taken into the abnormality detection device 7 as initial pressure data P0 and initial temperature data T0, respectively.

Next, it is determined whether the initial pressure data P0 and the initial temperature data T0 are within a rough normal range set in advance in the abnormality detection device 7 (S104).
When the pressure and temperature of the fuel mixture G3 are out of the rough normal range, it is considered that some abnormality has occurred in the stationary engine 2, and the operation of the stationary engine 2 is abnormally stopped (S105). ).

Next, when the measured power generation output W0 is within the rough normal range, the power generation output W0 is taken into the abnormality detection device 7 as initial power generation output data W0 at the start of abnormality diagnosis. The initial power generation output data W0 is set as the power generation output expected value Ws (i-1) at the past time, and the initial pressure data P0 and the initial temperature data T0 are converted into the pressure data P (i-1) and the past time. Let it be temperature data T (i-1). Also, the number of replacement times C is initialized to 1 (S106).
Note that S101 to S106 are performed only when the engine is started (when abnormality diagnosis is started) when the abnormality is detected.

  Next, as shown in FIG. 3, as the capture step in the abnormality detection loop, the power generation output at the present time, the pressure and temperature of the fuel mixture G3 are measured, and the power generation output data W (i) and pressure data P (i, respectively) are measured. ) And temperature data T (i) are taken into the abnormality detection device 7 (S107).

Next, as an assumed value calculation step, the estimated power generation output value Ws (i) at the time of determination is calculated from the assumed value calculation relational expression (S108).
Further, at the first determination time in the abnormality detection loop, the initial power generation output data W0 is the power generation output expected value Ws (i-1) at the past time. The initial pressure data P0 and the initial temperature data T0 are the pressure data P (i-1) and temperature data T (i-1) at the past time point.
And each said data is substituted for the said estimated value calculation relational expression, and the electric power generation output estimated value Ws (i) in the determination time is calculated.

Next, as an abnormality determination step, determination data X (i) at the determination time is calculated from the determination relational expression (S109).
That is, the power generation output data W (i) at the current time point is set as the power generation output data W (i) at the determination time point, and the power generation output data W (i) at the determination time point and the power generation output expected value Ws (i) at the determination time point are obtained. Substituting into the determination relational expression, the determination data X (i) at the determination time is calculated.

Next, it is determined whether or not the determination data X (i) at the determination time is out of the predetermined reference range A (S110).
When the determination data X (i) at the determination time is out of the predetermined reference range A, the abnormality detection device 7 considers that there is a sign of detecting an abnormality, and sets an abnormality flag indicating this sign. (S111). After that, it is determined whether or not the abnormality flag has been continued for a predetermined number of times (in this example, 5 times) from the previous determination time (S112). When the abnormality flag continues to stand for a predetermined number of times, it is assumed that some abnormality has occurred in the stationary engine 2, and the stationary engine 2 is abnormally stopped (S113).

  On the other hand, when the determination data X (i) at the determination time is within the predetermined reference range A in S110, or when the abnormality flag has not been kept standing for the predetermined number of times in S112, the replacement number C is set to the predetermined number of times. It is determined whether or not (5 times in this example) (S114). If the replacement count C is not the predetermined count, the replacement count C is counted (S115). Thereafter, the estimated power generation output value Ws (i) at the determination time (current time) is set as the power generation output estimated value Ws (i−1) at the past time, and the current pressure data P (i) and temperature data T (i). Is the pressure data P (i-1) and temperature data T (i-1) at the past time (S119), and S107 is executed as the next determination time.

On the other hand, when the number of replacement times C reaches a predetermined number, it is determined whether or not an abnormality flag has been set even once during the predetermined number of times (S116). When the abnormality flag has not been raised even once within the predetermined number of times, the power generation output data W (i) at the determination time is replaced with the power generation output estimated value Ws (i) at the determination time (S117). ).
Thereafter, the number of replacements C is initialized to 1 (S118), S119 is performed, and S107 is performed as the next determination time.

  When the above replacement is performed, it is estimated that the abnormality flag is not raised once during the predetermined number of times, and the possibility that an abnormality will occur in the stationary engine 2 is low. Then, when each step is performed after the determination time point at which the replacement is performed, the power generation output data W (i) at the determination time point is used, and at the next determination time point, the power generation output expected value Ws (i− Used as 1). As a result, the power generation output expected value Ws (i), which is a theoretical value, and the power generation output data W (i) obtained by actually performing the measurement due to an accumulated error or the like generated each time the abnormality detection device 7 repeats each step. ) Can be prevented from occurring.

If the abnormality flag is raised even once during the predetermined number of times, the replacement is not performed, the number of replacements C is initialized to 1 (S118), and after performing S119, the next determination time is S107. Execute.
When the replacement is not performed, it is estimated that there is a high possibility that an abnormality will occur in the stationary engine 2. In this case, the difference generated between the power generation output expected value Ws (i) and the power generation output data W (i) is maintained, and the determination data X (i) is again set to a predetermined reference in the abnormality determination step. The range A is easily removed. Thereby, when it is estimated that there is a high possibility that an abnormality will occur, the sensitivity for detecting the abnormality can be improved.

  Thereafter, the above determination step (S107), assumed value calculation step (S108), and abnormality determination step (S109 to S119) are repeated with the determination time point set as the past time point and the next time point as the sequential determination time point. The presence or absence of abnormality in the stationary engine 2 can be monitored.

  In S108, at the second and subsequent determination times, the power generation output estimated value Ws (i) calculated at the previous determination time becomes the power generation output estimated value Ws (i-1) at the past time point. The pressure data P (i) and temperature data T (i) measured at the determination time are pressure data P (i-1) and temperature data T (i-1) at the past time. And each said data is substituted for the said assumption value calculation relational expression, and the electric power generation output assumption value Ws (i) in the determination time after the 2nd time is calculated.

  By the way, when a mechanical abnormality such as seizure occurs in the stationary engine 2, the power generation output of the generator 3 decreases or does not increase so much because the loss in the stationary engine 2 increases. At this time, since the power generation output of the generator 3 does not reach a predetermined target power generation output, the control device 5 increases the opening of the governor 43. Thereby, the pressure of the fuel mixture G3 in the intake manifold 4 is significantly increased. Therefore, at this time, the determination data X (i) in the abnormality determination step repeatedly deviates from the predetermined reference range A, and the abnormality detection device 7 can detect that an abnormality has occurred in the stationary engine 2.

As described above, the abnormality detection device 7 uses the correlation between the pressure of the fuel mixture G3 and the power generation output, and uses the correlation between the state quantities as the change in the pressure of the fuel mixture G3 and the change in the power generation output. By monitoring such changes, it is possible to detect whether an abnormality has occurred in the stationary engine 2.
Therefore, for example, even when there is a difference in the absolute value as the power generation output value with respect to the pressure value of the fuel mixture G3 due to a change in engine characteristics over time, the abnormality can be detected accurately and quickly.

  The pressure of the fuel mixture G3, the temperature of the fuel mixture G3, and the power generation output of the generator 3 are measured by pressure measuring means 51, temperature measuring means 52 and power generation used for controlling or monitoring the power generation system 1. This can be done using the output measuring means 53. Therefore, it is not necessary to separately provide a sensor (measurement means) as special hardware in order to perform the abnormality detection, and the configuration of the abnormality detection device 7 can be simplified.

Further, the pressure measuring means 51, the temperature measuring means 52 and the power generation output measuring means 53 are used in almost all types of power generation systems 1. Therefore, the abnormality detection device 7 can be realized without adding hardware such as a sensor to most types of power generation systems 1 and is excellent in versatility.
Therefore, according to the abnormality detection device 7 of the present example, the abnormality that has occurred in the stationary engine 2 can be quickly detected with high detection accuracy by a simple device configuration. Can be provided.

  Further, as described above, when the abnormality detection device 7 repeatedly performs the assumed value calculation step and the abnormality determination step, when the determination data X (i) is out of the predetermined reference range A continuously for a predetermined number of times. By detecting the abnormality for the first time, the detection accuracy of the abnormality detection device 7 can be further enhanced.

(Abnormality detection example)
In FIG. 4, the result of having detected the abnormality in the stationary engine 2 by the said abnormality detection apparatus 7 is shown. In the figure, the horizontal axis represents time, and the vertical axis represents fuel mixture pressure (pressure data) P (i), fuel mixture temperature (temperature data) T (i), power generation output expected value Ws (i), It is a graph which shows the state of detection of abnormality, taking the presence or absence of power generation output (power generation output data) W (i) and an abnormality flag.

In this case, the time interval for taking in the power generation output data W (i), pressure data P (i), and temperature data T (i) is 1 (s), and the above replacement is performed every time the abnormality determination step is performed five times. Judgment was made. In this example, the predetermined reference range A is 3% or less.
In the figure, the pressure of the fuel gas mixture G3 starts to rise from the vicinity of 75 to 80 (s), and the actual power generation output rises so much as the power generation output expected value Ws (i) increases. Therefore, it can be estimated that an abnormality has occurred. Then, the abnormality flag continued to stand from the time of about 100 (s), and the abnormality detection device 7 was able to perform an abnormal stop of the stationary engine 2 in the vicinity of 100 (s).
In the figure, the fuel mixture pressure P (i), the fuel mixture temperature T (i), the estimated power generation output value Ws (i), and the power generation when the abnormal stop is not performed after about 100 (s). The transition state of the output W (i) and the presence / absence of an abnormality flag is also shown.

Table 1 shows the situation where the abnormality detection device 7 detects the abnormality.
In the table, the power generation output (power generation output data) W (i) and the power generation output estimated value Ws (i) are shown as percentages relative to the rated output. The determination data X (i) is expressed as a percentage, and the predetermined reference range A is 3% or less.
In the same table, since the abnormality flag has not been raised even once at times 86 to 90 (s), at time 90 (s), the power generation output at this time is replaced with the power generation output estimated value Ws (i). Went. At time 91 (s), the power generation output data W (i-1) at time 90 (s) is added to the pressure change rate P (i) / P (i-1) and temperature change at time 91 (s). The estimated power generation output value Ws (i) was calculated by multiplying by the ratio T (i-1) / T (i).

  In addition, since the abnormality flag is set once or more at times 91 to 95 (s), the above replacement was not performed at time 95 (s). At time 96 (s), the estimated power generation output value Ws (i-1) at time 95 (s) is changed to the pressure change rate P (i) / P (i-1) and temperature at time 96 (s). The estimated power generation output value Ws (i) was calculated by multiplying the change rate T (i-1) / T (i).

  Then, after the time 99 (s), the abnormality flag has continued to stand 5 times or more, so the abnormality detection device 7 detects an abnormality of the stationary engine 2 and quickly stops the stationary engine 2 abnormally. I was able to. In addition, it turned out that the abnormality which generate | occur | produced in the stationary engine 2 was the burning of the connecting rod. As described above, according to the abnormality detection device 7, the stationary engine 2 can be urgently stopped before the abnormal state in the stationary engine 2 deteriorates and secondary damage occurs in the stationary engine 2. I understood.

When the abnormality detection device 7 is applied to a diesel engine, the abnormality detection device 7 determines the flow rate (velocity) of the fuel supplied to the stationary engine 2 instead of measuring the pressure of the fuel mixture G3. Can be measured. Then, the abnormality detection device 7 uses the measured flow rate as the flow rate data, and in the assumed value calculation step, the flow rate change rate of the flow rate data at the determination time with respect to the flow rate data at the past time point and the estimated power generation output value at the past time point From the relationship with Ws (i−1) (or power generation output data W (i)), the power generation output estimated value Ws (i) at the determination time can be calculated.
Even in this case, the other configurations can be the same as those of the above-described embodiment, and the same effects as those of the above-described embodiment can be obtained.

Explanatory drawing which shows the structure of the electric power generation system in an Example. The flowchart which shows the flow of the initial stage of the abnormality detection by the abnormality detection apparatus in an Example. The flowchart which shows the flow of the abnormality detection loop by the abnormality detection apparatus in an Example. The graph which shows the state of the detection of abnormality, taking time on a horizontal axis in an Example, and taking pressure data, temperature data, power generation output assumption value, power generation output data, and the presence or absence of an abnormality flag on the vertical axis.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power generation system 2 Stationary engine 3 Generator 4 Intake manifold 51 Pressure measurement means 52 Temperature measurement means 53 Power generation output measurement means 6 Control apparatus 7 Abnormality detection apparatus G3 Fuel mixture P (i) Pressure data T (i) Temperature data W (I) Power generation output data Ws (i) Power generation output expected value X (i) Judgment data A Reference range

Claims (5)

An abnormality detection device for detecting an abnormality in the stationary engine, which is used in a power generation system that operates a generator by the output of the stationary engine,
The abnormality detection device sequentially measures the pressure of the fuel mixture supplied to the stationary engine and the power generation output of the generator, and sequentially stores the measured pressure and power generation output as pressure data and power generation output data. Configured to
The time point at which the measurement is performed is set as a determination time point, and the time point at which the measurement is performed immediately before the determination time point is a past time point. The pressure change rate of the pressure data at the determination time point relative to the pressure data at the past time point An assumed value calculation step for calculating a power generation output assumed value at the determination time from a relationship with the power generation output assumed value at the past time;
When the determination data calculated based on the ratio or difference between the power generation output data at the determination time and the power generation output estimated value at the determination time is out of a predetermined reference range, an abnormality occurs in the stationary engine. An abnormality detection device for a power generation system, wherein the abnormality determination step for detecting the occurrence of the abnormality is repeatedly performed each time the measurement is performed. In Claim 1, the abnormality detection device is configured to sequentially measure the temperature of the fuel mixture and sequentially store the measured temperature as temperature data.
In the assumed value calculating step, the abnormality in the power generation system is configured such that the pressure change rate is corrected by a temperature change rate of the temperature data at the determination time with respect to the temperature data at the past time. Detection device. An abnormality detection device for detecting an abnormality in the stationary engine, which is used in a power generation system that operates a generator by the output of the stationary engine,
The abnormality detection device sequentially measures the flow rate of fuel supplied to the stationary engine and the power generation output of the generator, and sequentially stores the measured flow rate and power generation output as flow rate data and power generation output data. Configured,
The time point at which the measurement is performed is set as a determination time point, and the time point at which the measurement is performed immediately before the determination time point is a past time point. The flow rate change rate of the flow rate data at the determination time point with respect to the flow rate data at the past time point An assumed value calculation step for calculating a power generation output assumed value at the determination time from a relationship with the power generation output assumed value at the past time;
When the determination data calculated based on the ratio or difference between the power generation output data at the determination time and the power generation output estimated value at the determination time is out of a predetermined reference range, an abnormality occurs in the stationary engine. An abnormality detection device for a power generation system, wherein the abnormality determination step for detecting the occurrence of the abnormality is repeatedly performed each time the measurement is performed.   The abnormality detection device according to any one of claims 1 to 3, wherein the abnormality detection device detects an abnormality in the stationary engine when the determination data continues out of the predetermined reference range for a predetermined number of times in the abnormality determination step. An abnormality detection device in a power generation system, wherein the abnormality detection device is configured to detect occurrence of a fault. In claim 4, when the abnormality detection device repeatedly performs the assumed value calculation step and the abnormality determination step a predetermined number of times,
If the determination data does not deviate from the predetermined reference number within the predetermined reference range during the predetermined number of times, the power generation output data at the determination time corresponding to the predetermined number of times is set as the power generation output expected value at the determination time. Replace
On the other hand, the abnormality detection device in the power generation system is configured such that the replacement is not performed when the determination data deviates from the predetermined reference range more than the reference number within the predetermined number of times.

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