JPH03235032A - Breakdown predicting-diagnosing apparatus of diesel engine - Google Patents

Abstract

PURPOSE:To improve the reliability of a plant by detecting the adjusting position of a control rack and the rotating number of an engine by a sensor, and judging it as a sign of a break down when the difference between a theoretical output of the engine presumed from the detecting signal and an actual output of the engine is not smaller than a set value. CONSTITUTION:Signals from a potentiometer 101 and a revolution sensor 102 are fed to a theoretical output presuming device 107 which in turn obtains a presuming theoretical output at the current time based on each signal input thereto. A pressure signal when a supercharger presses is taken into an actual output presuming device 108, so that a presuming value of the actual output at the current time is obtained. when the difference between the presuming output values and actually-measured output value detected by a torque meter 103 is within a set value, and if the difference between the presuming output value and theoreti cal output value is not smaller than the set value, a comparing/detecting device 109 judges it as a sign of a breakdown. The difference after a set time is predicted from the changing tendency thereof with time, and if the difference exceeds the set value, it is detected as a sign of a breakdown. Moreover, when the difference between the presuming output value and actually-measured value is over the set value, either sensor is judged to be broken. The judging result is displayed at a CRT 110.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a failure prediction/diagnosis device applied to a diesel engine that drives a pump in a rainwater drainage pump station or the like.

[Conventional technology]

Diesel engines are equipped with sensors for lubricating oil temperature, cooling water, temperature, etc., and when the lubricating oil temperature exceeds a set value, for example, a warning is issued and an interlock is activated to stop the engine. In this way, a mechanism is provided to stop the engine when a typical event leading to a serious failure occurs, and subsequent maintenance is performed. In addition, as part of preventive maintenance, regular inspections, overhauls, and parts replacements are performed.

FIG. 4 shows the general configuration of the conventional device, in which 1 is the engine body, 2 is the reducer, 5 is the pump body, and 4 is the supercharger of the engine body J.

In the above configuration, the engine is rotated and the pump 3 is rotated via the reduction gear 2 to perform drainage, for example. There are various other piping and auxiliary equipment in the plant, but they are omitted for simplicity. The engine body 1 is provided with a plurality of sensors 5 for measuring temperature, pressure, etc., and are incorporated into an interlock circuit 6. In accordance with its logic, the interlock circuit 6 generates an alarm from the alarm device 7 when the sensor signal exceeds a set value or a combination thereof, and issues an engine/shin stop command. When the engine main body 1 receives a stop command, it stops the engine by, for example, stopping fuel injection.

The present invention has been devised in view of the above-mentioned circumstances, and it is possible to detect abnormalities before serious failures occur, and to enable engine inspections to be carried out online, thereby eliminating the need to increase the burden of inspections on operators and quickly. It is an object of the present invention to provide a diesel carrot failure prediction/diagnosis device that can perform regular inspections, prevent false alarms due to sensor failure, and improve reliability.

[Problem to be solved by the invention]

When an alarm is generated and an abnormality is detected, the engine must be stopped. If this situation occurs during an emergency (during rain), the drainage pump station will not be able to perform its functions.

Since the pump mechanism is operated periodically for maintenance (referred to as maintenance operation), it is necessary to improve the reliability of the plant by eliminating the causes of serious failures during normal times. However, increasing the number of items inspected by conventional operators increases the burden, and detailed inspections such as O/S-holes are time-consuming and costly, and may increase early failures, so inspections can be performed online. It is desirable to implement the following.

Further, among serious failures that prevent the engine from operating, failures in the fuel injection system have a high probability of occurring, so it is desired to detect failures in this system early.

[Means and effects for solving the problems] The present invention provides: (1) a means for detecting the adjustment position of the control rack and the engine rotation speed using a sensor, and estimating the theoretical output of the engine from this signal; (2) supercharging. (3) Measuring the engine output directly with a sensor and estimating the actual engine output value by detecting the machine pushing pressure with a sensor;
1) Compare with the estimated value of (2), and if the difference between the estimated output value of (2) and the actual measured value of (3) is within the set value, (
If the difference between the estimated output value in 2) and the theoretical output in (1) exceeds a set value, it is determined that there is a sign of failure.

Further, the difference after a set time is predicted from the temporal trend of the difference, and if the difference exceeds the set value, it is determined that there is a sign of failure.

(2) If the difference between the estimated output value in (2) and the measured value in (3) exceeds the set value, it is determined that one of the sensors is at fault.

(4) Means for notifying the operator of the determination result in (3);
It is equipped with the following.

In the above configuration, since the amount of fuel injected in one cycle of the engine is determined at the control rack position, the theoretical output of the engine can be estimated from this and the tachometer. Furthermore, since the supercharger pushing pressure is proportional to the engine output, the engine output can be estimated.

The power output is the original performance of the engine.

When a failure factor occurs in the fuel system, injection system, exhaust system, cold trout system, lubricating oil system, etc., engine performance deteriorates, resulting in a difference between the actual engine output and the theoretical output. The means detects this difference or predicts the tendency of the difference in output and notifies the operator. The engine output value is directly measured, and if the difference between the engine output value and the estimated output value based on the supercharger pushing pressure becomes large, it is determined that one of the sensors has failed, and the operator is notified of the result.

The present invention also provides: (1) a means for detecting the adjustment position of the control rack and the engine speed using a sensor and estimating the fuel consumption amount per unit time from this signal; ) A means for determining that a sign of failure has been detected when the consumption increases significantly based on the temporal change in the estimated value of fuel consumption, (3) determining the total fuel consumption over a certain period of time using the estimated value of (1) (4) Measuring the actual fuel consumption in the fuel tank,
Means for determining that there is a leak in the fuel system from the fuel tank to the cylinder when the consumption amount in the fuel tank is greater than the set value compared to the estimated value in (3) (5) (2) (4) above The system is equipped with means for notifying the operator of the determination result.

In the above configuration, since the control rack position determines the fuel injection amount in one engine cycle, the fuel consumption per unit time can be determined from this and the rotational speed. Controlled operation is usually performed with the same load, and in emergencies, it is often operated at the rated value. If the load is the same, the fuel consumption will be the same.

However, when a failure factor occurs in the fuel system, injection system, exhaust system, cooling water system, lubricating oil system, etc., engine performance decreases and as a result, fuel consumption increases. In other words, fuel efficiency is required. Therefore, by means (1) and (2), it is detected that the fuel efficiency has deteriorated, and this is taken as a sign of failure, and the means (5) is used to notify the operator.

Further, by integrating the fuel consumption amount per unit time in (1) for a certain period of time, the total consumption amount for that time can be determined. By means of (4), if the actual consumption is significantly higher than the estimated value, it is determined that there is a leak in the fuel system, and the operator is notified of this.

[First embodiment Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration example of the first embodiment, FIG. 2 is a schematic diagram of an engine system, and FIG. 3 is a diagram for explaining a determination method for detecting signs of failure.

In FIG. 1, 1 is an engine body, 2 is a speed reducer, 3 pumps, 4 is a supercharger, 5 is various measurement stations, 6 is an interlock circuit, and 7 is an alarm device.

Additionally, 101 to 104 sensors are used to measure the control rack position, a potentiometer that measures the engine speed, a tachometer that measures the engine speed, a torque meter that measures the engine output, and a supercharger push pressure gauge. The outputs of these sensors 101-104 are sent to transmitters 105h-105d and noise filters 106a-
It is transmitted to the theoretical output estimator 107, the actual output estimator 108, and the comparison/determination unit 109 via 106d. The voltage ql 01 and the signal from the tachometer 102 are sent to the theoretical output estimator 107 . If the values of each signal input to the theoretical output estimator 107 are X and r, then at the current time, C1
, C2 are constants, and t is the measurement time to determine the average output per unit time.

That is, the fuel injection amount is (usually) proportional to the rack position xt. Moreover, the output is macroscopically proportional to the amount of fuel. Therefore, △ Pt=a* F (2) p=b
, *(xt+b2)*rl/(60*S) (3
). However, East: Output torque [kym] F: Fuel consumption per unit time [yu] r,: Engine rotation speed [rpm] xt position [m] S: For 4-cycle engine = 2 For 2-stroke engine = 1 b2 Nirak position offset cancellation constant [m] b1:
Proportionality constant from rack position to fuel injection amount [ky/m]a
: Conversion constant [kpmA] from fuel amount to output.

Then, by substituting the above equation (2) into equation (1), △p, = a*b, *(x, +b2)xrt/(60*
S) Equation (4) is obtained. This equation (4) and (
If we compare the formulas (1), 01. of formula (1). The unit of C2 is c, = a*b1/(6o*s)=[kpm7][
1v/m]-[kgm/m] (=[kf]) C2=-b=[m].

In addition, the signals of the supercharger pushing pressure P and t are obtained by the actual output estimator 1
08, the estimated actual output value Pt at the current time is calculated using the following formula.
is required.

That is, as in the above case, since the supercharger pushing pressure P is proportional to the output P, at Pt=C5P, t+C4 (5).

P,: Output torque [Yumoko "at" Supercharger pushing pressure [Y/, /] C5: Proportionality constant to output torque C4: Offset cancellation constant c, , Considering the unit of C4, C3 = [l# 9m]/[kp/6n2]C4=
[kl? It becomes mko.

If the actual measured output value by the torque meter 103 is P, then
In the comparison/judgment unit 109, (1) In the case of summer P, -P, + (C0 (C0 is the set value), △ - C1 = I Pt - P, l≧e, (6) e is the estimated output value. When the difference, ε, is a set constant, it is determined that there is a sign of failure, and the CRT J J.

to be presented. As shown in Figure 3, during past management operation (k,
-1, -1, etc.) and the current measurement value to predict the value 7 hours later. For example, there is the exponential smoothing method. The estimated value after 1 hour of the actual output is divided into Pt+ and -, and the theoretical value is 7.
If the predicted value after time is Pt+□, then C2""t+/
't+/l≧t2 (7) If l and t2 are set constants, it is determined that the sign of failure will be resolved after 1 hour, and CR
Presented at T 110. This prompts operators to strengthen monitoring and make repairs.

(2) lPtPt1==e5≧ε. In the case of 03≧ε as shown in FIG. In this case, it is assumed that the pressure gauge 104 or torque meter 103 is malfunctioning. This is CRT J
10 Inform the operator.

Figure 2 schematically shows the engine system.
main parts of the engine such as the cylinder, cylinder head, cam, piston, crankshaft, 11 is the injection pump, 1
2 fuel tanks, 13 air coolers, 14 lubricating oil reservoir, 15 lubricating oil pump, 16 lubricating oil cooler, 17*,
17b is a cooling water pump, and 18 is a supercharger.

In Figure 2 above, failures in the fuel injection system, air supply/exhaust system, and lubricating oil system, such as dirt on the lubricating oil cooler, reducing cooling ability, and soot adhering to the injection nozzle, can cause problems in the engine. This leads to performance deterioration.

In the above embodiment, the performance degradation of these engines is detected from the difference between the estimated actual output value and the estimated output value at the current time, and
Since a warning is issued based on the predicted output value after one hour, serious failures can be prevented by strengthening monitoring or repair.

Components that are the same as those in the embodiment shown in FIG. 1 are given the same reference numerals, and detailed explanations will be omitted. The fuel is injected into the engine body 1 from the fuel tank 12 as shown in the engine system schematic diagram in FIG.
Fuel is supplied via the connector. Above fuel tank 1
2 is provided with a water level gauge (oil level gauge) 12 as a sensor. The output of this water level gauge 121 is transmitted to the transmitter 105
Comparison/judgment unit 1 via ac and noise filter 106*
Sent to 09. The outputs of the potentiometer 10 and the tachometer 102 in the engine body 1 are transmitted to the transmitter 105b.

105c and noise filters 106b and 106c to the unit time fuel consumption estimator 107*. The output of this unit time fuel consumption estimator 107a is
09* is inputted to the comparison/determination unit 109* via the kit consumption estimator 108g. Furthermore, the load signal at each time is input to this comparison/determination device 109m. This comparison/judgment device 109a detects engine performance deterioration, fuel leakage, etc. from the above input signals, and detects the CRT 11.
0, and is configured as shown in FIG.

That is, the comparison/judgment device 109 &
m, 20b, storage device 21. It is composed of an approximate curve estimation M22, a differentiator 23, a bistable 24, an OR circuit 25, an actual consumption estimator 26, an adder 22, and a pie staple 281C, and calculates the unit time fuel consumption and load at each time from the estimator 107 &. The signal is sent from the oil level gauge 121 to the pie staples 20* and 20b via the transmitter 105a and the noise filter 106m.The fuel tank water level is sent from the actual consumption estimator 26/C1 total consumption estimator 108a. The total consumption amount is input to one terminal of the adder 27. Then, the output signals of the pie staples 20m and 20b are outputted to the OR circuit 25.
Then, the data stored in the storage device 2 becomes the estimated approximate curve value 22. The signal is input to an OR circuit 25 via a differentiator 23 and a pie staple 24.

The output signal of this OR circuit 25 becomes a failure signal indicating a decrease in engine performance.

Further, the output signal of the actual consumption estimator 26 is transmitted to the estimator 108.
It is input to an adder 27 along with the total consumption amount from a, and the output of this adder 27 is taken out via a pipe staple 28 as a leak failure detection signal in the fuel system.

Next, the operation of the above embodiment will be explained.

The unit time fuel consumption estimator 1071L receives the control rack position and engine speed. Since the fuel injection amount is determined by the rack position, the consumption amount per unit time is estimated by the following equation.

△ Vs== C, X (X, + C2) X r,
(8) Here, C1 and C2 are constants x, : Control rack position (time t) r, : Engine rotation speed (l ) + 3 Estimated fuel consumption for two unit times The constants C1 and C2 in equation (8) above are , is the same as in the case of equation (3) above. That is, it can be considered as follows: △ V → F C1 → b1/(60*5) C2 → b2. In this case, the dimensions of C4 are as follows.

△vII obtained by the unit time fuel consumption estimator 1071 is further output to the total consumption estimator 108m,
The consumption amount for a certain period of time T=(t2-tl) can be calculated using the following formula.

Here, ΔV: Total consumption estimated value Δt: Corresponds to unit time ΔVll and ΔVll determined by the estimators 107m and 108m are input to 20b. pie staple c, =
b 1/ (60IS) = [kg/m;! OI
L, 20b outputs the detection result to the CRT J 10, assuming that engine friction has decreased when ■ is equal to or greater than the set value. However, this pie table 20. .

20b is allowed to output only when the load is within a set range. For example, low load β±6 during controlled operation
2. Set a range of 2.5% and a range of α±e1% at rated time.
If the current load is within either range, detection output is permitted. Naturally, it is also possible to increase the number of pie staples.

Further, the measurement results during operation are thinned out and stored in the storage device 2. As a result, as shown in FIG. 6, it is possible to know the change in fuel consumption over time. The approximate curve estimator 22 uses data in the storage device 21 within a set period to obtain an approximate curve by, for example, the most d-square method. The differentiator 23 determines the current slope of the approximate curve. If this value exceeds the value set by pie staple 24, it is determined that the fuel consumption has deteriorated significantly and is output to the CRT 710 to notify the operator.

On the other hand, the total consumption V output from the total consumption estimator 108IL is input to the adder 27. Time t.

Estimator 2 from the amount of decrease in the water level of the fuel tank at 121 from
6, the actual consumption amount is determined and inputted to the adder 27Δ. If the value obtained by subtracting V from the actual consumption amount exceeds the value set in the pie table 28, the fuel has decreased abnormally and it is determined that there is a fuel leak in the fuel injection system shown in Figure 2 above. , CRTIIOI/C output.

As described above, by recognizing deterioration in fuel efficiency as a sign of failure and notifying the operator before a warning or serious failure occurs, the operator can perform repairs with enhanced monitoring to prevent serious failures. Furthermore, leakage can be detected from the way the fuel is reduced, and as a result, the reliability of the plant can be improved.

The present invention can be applied to diesel engines for power generators and diesel engines for ships, as well as diesel engines that drive pumps in rainwater drainage pump stations and the like.

〔Effect of the invention〕

As described above, according to the present invention, deterioration in engine performance and deterioration in fuel efficiency can be recognized as a sign of failure and can be notified to the operator before an alarm or serious failure occurs. You can strengthen or repair it to prevent serious breakdowns.

As a result, the reliability of the plant can be improved.

Since detection can be performed online, it is quick and there is no need to increase the burden of inspection on operators.

Furthermore, since sensor failure can be detected, reliability deterioration due to false alarms can be reduced.

Furthermore, fuel leaks can be detected from the way the fuel is reduced, improving the reliability of the plant.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of a diesel engine failure prediction/diagnosis device according to a first embodiment of the present invention, Fig. 2 is a schematic diagram of an engine system in the same embodiment, and Fig. 3 is a failure prediction/diagnosis device in the same embodiment. FIG. 4 is a block diagram showing the configuration of the second embodiment of the present invention; FIG. 5 is a block diagram showing the configuration of the comparison/judgment device in the same embodiment; FIG. The figure is a diagram for explaining the determination method for detecting failure signs according to the same embodiment, and FIG. 7 is a block diagram showing the configuration of the conventional device. DESCRIPTION OF SYMBOLS 1... Engine main body, 2... Reducer, 3... Pump main body, 4... Supercharger, 5... Sensor, 6... Interlock circuit, 7... Alarm, 101... Potentiometer (for control rack position measurement), 102...
Tachometer, (for measuring engine speed), 103...torque meter (for measuring engine output), 104...pressure gauge (for measuring supercharger pushing pressure), 1051-105d...
Transmitter, 106a-106d-Noise filter, 107
. . . Theoretical output estimator, 107a . . . Unit time fuel consumption estimator, 108 . , 11... Injection tank, 12... Fuel tank, 13... Air cooler, 14... Lubricating oil reservoir,
15... Lubricating oil pump, 16... Lubricating oil cooler, 1
7*, 17b...Cooling water pump, 18...Supercharger.

Claims (3)

[Claims] (1) In a diesel engine equipped with an injection pump and a supercharger that adjust the amount of fuel using a control rack, there are a potentiometer that detects the adjustment position of the control rack, a pressure sensor that detects the supercharger pushing pressure, and engine rotation. a tachometer for detecting the number of rotations, a theoretical output estimation means for estimating the theoretical output of the engine from the position of the control rack and the engine rotation speed detected by the potentiometer and the tachometer, and a means for estimating the theoretical output of the engine from the supercharger pushing pressure. The actual output estimating means for estimating the output compares the theoretical output and the actual output output from the above estimating means, and determines whether the difference is within the set value range or within the set time based on the temporal trend of each. 1. A failure prediction/diagnosis device for a diesel engine, comprising a determining means for determining that there is a sign of a failure when it is determined that a set value is exceeded, and a notifying means for notifying the result of the determining means. (2) In a diesel engine equipped with an injection pump that adjusts the fuel amount using a control rack, there is a potentiometer that detects the adjustment position of the control rack, a tachometer that detects the engine rotation speed, and a tachometer that detects the amount of fuel detected by the potentiometer and tachometer. An estimation method for estimating fuel consumption per unit time from the control rack position and engine rotation speed, and when there is a significant tendency for fuel consumption to increase based on the temporal change in fuel consumption when driving with the same load. 1. A failure prediction/diagnosis device for a diesel engine, comprising a determination means for determining that there is a sign of a failure, and a notification means for notifying an operator of the result of the determination means. (3) In a diesel engine equipped with an injection pump that adjusts the fuel amount using a control rack, a potentiometer that detects the adjustment position of the control rack, a tachometer that detects the engine rotation speed, and a tachometer that detects the amount of fuel detected by the potentiometer and tachometer. an estimating means for estimating fuel consumption per unit time from the control rack position and engine rotation speed; and a total consumption estimating means for estimating the total consumption by integrating the fuel consumption estimated by this means for a certain period of time; consumption amount detection means for detecting the amount of fuel consumed in the fuel tank;
The total consumption estimated by the total consumption estimation means is compared with the consumption detected by the consumption detection means, and if the consumption in the fuel tank is greater than the set value, it is determined that there is a fuel leak in the fuel injection system. 1. A failure prediction/diagnosis device for a diesel engine, comprising a determining means for making a determination, and a notifying means for notifying the result of the determining means.