JP2686882B2 - Cooler operation determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooler operation judging device for judging the operation state of a cooler mounted mainly on a vehicle.

[0002]

2. Description of the Related Art For example, when a cooler mounted on a vehicle is installed in the vehicle, it is necessary to determine whether or not the cooler operates normally. The operator's sensory judgment was made as to whether or not the temperature of the air discharged from the discharge port of No. 2 was lowered, and if the temperature was felt not to have fallen, the operating state of the cooler was judged to be defective. However, the judgment result may differ depending on the operator's sensuality depending on the individual difference of the worker, and it is judged to be normal even if it is not operating normally when the intake temperature and ambient temperature are low such as in winter. May occur. Although it is possible to determine the operating state of the cooler by detecting the energization state of the electromagnetic clutch of the condenser fan and compressor, which are the components of the cooler, it is necessary to perform work such as removal of the coupler, As the number of work steps increases, there is a risk of problems such as forgetting to attach the coupler after the inspection.
Therefore, it is desired to make an objective and simple determination of the operating state of the cooler, rather than relying on the operator's sensuality.

By the way, Japanese Patent Laid-Open No. 56-36029 discloses, for example, an enthalpy measuring device for detecting a temperature and relative humidity of exhaled air from a cooling and heating machine and calculating an enthalpy based on the detected data to obtain a cooling and heating load. However, the enthalpy measuring apparatus cannot accurately obtain the cooling / heating load unless the atmosphere in which the cooling / heating machine or the like to be measured is installed is kept in a constant state. However, when determining the operating state of the vehicle-mounted cooler, it is technically possible, but costly, to place the vehicle equipped with the cooler in a temperature-controlled room or the like to keep the atmosphere of the entire vehicle constant. Therefore, the enthalpy measuring device described in the above publication cannot be used for determining the operation of the cooler mounted on the vehicle because it cannot be actually performed.

[0004]

In view of the above problems, the present invention provides a cooler capable of objectively determining the operating state of the cooler even if the atmosphere in which the cooler is placed is not constant. An object is to provide an operation determination device.

[0005]

[0006]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
According to the present invention, there is provided a cooler operation determination device for detecting the energy of exhaled gas discharged from a discharge port of a cooler and determining whether the operating state of the cooler is good or bad based on the detected exhaled energy. The actual detected exhaled gas is provided with an atmosphere detecting means for detecting the above, and a storage means for preliminarily storing the maximum value of the rate of change over time of the exhaled energy due to the operation from the predetermined atmosphere and the intake air temperature at this time as reference data. The maximum value of the rate of change of energy with time is converted into comparison data based on the temperature difference between the intake air temperature at this time and the intake temperature of the reference data, and the comparison data and the maximum value of the reference data are compared, and both data are compared. When the deviation of is outside a predetermined normal range, it has an operation determination means for determining the operation state of the cooler as defective.

[0007]

[Action] through of actual nausea energy, which is determined by measurement
When the maximum value of the time change rate is converted into comparison data that can be compared with the reference data according to the actual atmosphere condition at the time of measurement, and the deviation of the comparison data from the reference data is out of the allowable normal range, Determines that the cooler operation is defective so that the reference data and the comparison data can be compared even if the cooler atmosphere changes, and the influence of the atmosphere on the cooler operation determination is eliminated.

When the operation of the cooler is started, even if the sucked air is cooled, heat is transferred from the wall surface of the air passage or the like until the air is discharged, so that the exhaust gas energy is gradually reduced. The rate of decrease in exhaled energy increases as the amount of heat transfer from the same decreases, and thereafter, the rate of decrease in exhaled energy decreases as the intake air temperature decreases. Therefore, the change rate of the exhalation energy becomes maximum when a predetermined time has elapsed after the start of the cooler operation. Since the predetermined time when the rate of change of the exhaled energy becomes maximum varies depending on the atmospheric state at the time of starting the operation, the change rate of this change rate is set not as the elapsed time from the start of the operation but at the time when the rate of change of the exhaled energy becomes maximum. It was decided to compare the reference data and the comparison data with respect to the maximum value, that is, the slope at the inflection point of the change in exhaled energy.
It should be noted that the maximum value is corrected based on the temperature difference between the intake temperature at the time when the maximum value that is the reference data is generated and the intake temperature at the time when the maximum value that is the basis of the comparison data is generated to obtain the comparison data. did.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment for determining the operating state of a cooler mounted on a vehicle, where 1 is set at a discharge port 11 from which air cooled by the cooler is discharged, It is an energy sensor that detects the exhaled energy from the outlet 11. The energy sensor 1 stores a known temperature sensor such as a thermocouple that detects the temperature Tout of the exhaled gas and a known humidity sensor that detects the relative humidity Hout of the exhaled gas. The energy sensor 1 also stores a well-known wind speed sensor that detects the wind speed V of the air discharged from the discharge port 11. On the other hand, cooler intake port 2
An atmosphere sensor 2 for detecting the atmosphere inside the vehicle is set in the vehicle 1, and, like the energy sensor 1, the well-known temperature sensor for detecting the temperature Tin of the intake air and the relative humidity Hin of the intake air are also set in the atmosphere sensor 2. A well-known humidity sensor for detecting is stored. Then, the detection signals from the energy sensor 1 and the atmosphere sensor 2 are input to the computer 3 via the sensor control device 31 having an A / D converter and a power supply for operating each sensor.

The computer 3 stores reference data obtained on the basis of exhaled energy in a predetermined atmosphere of the vehicle .

[0011]

By the way, since the changed state of the cooled air is a constant pressure change, the change in energy is indicated as a change in enthalpy. Therefore, using the well-known formula, the intake air temperature Tin
And the intake air humidity Hin, the intake air enthalpy is obtained, and this is used as the intake air energy Qin. temperature,
Actual changes in humidity and energy over time are shown in FIGS. 2 to 5 . In each figure, the wind speed V pulsates under the influence of the ON / OFF state of the compressor, so a leveling process is performed to prevent both energy from being affected by the pulsation of the wind speed V.

In the figure, the horizontal axis represents the elapsed time from the start of the cooler operation. In each curve, a is the intake air temperature Tin, b is the intake humidity Hin, c is the intake energy Qin, and
d is the temperature Tout of exhalation, e is the humidity Hout of exhalation, and f is the change over time of the energy Qout of exhalation.

By the way, when the operation of the cooler is normal as shown in FIGS. 2 and 3 , the compressor is temporarily stopped after a predetermined time has elapsed after the operation of the cooler is started, and then periodically restarted and restarted. Because it repeats, nausea energy Qou
t decreases rapidly until a predetermined time has elapsed, and then a pulsation phenomenon occurs. This is because when the compressor stops, the water droplets that have condensed on the surface of the evaporator re-evaporate during exhalation, so Hout rises rapidly, and when the compressor restarts, the temperature of the evaporator drops and condensing restarts. , Humidity Hout is Ho when the compressor continues to operate.
It is due to the rapid decrease to return to ut. on the other hand,
As shown in FIG. 4 and FIG. 5, when any part of the cooler is defective and the cooler is not operating properly, the temperature of the evaporator does not drop so much that water vapor in the air does not condense on the evaporator. Nausea energy Q as described above
No pulsation of out is seen. Paying attention to this point, it is possible to detect the presence or absence of the pulsation of the humidity Hout on the discharge side after a lapse of a predetermined time from the start of the operation of the cooler, and determine whether or not the operating state of the cooler is normal based on the presence or absence of the pulsation. .

In the case of the present embodiment, the actually measured exhalation energy Qout is corrected with reference to the intake air temperature Tin, and based on the deviation between the exhaled energy Qout thus corrected and the exhalation energy Qout in the reference state. The operation is determined by FIG. 6 shows a state in which the exhaled gas energy QR changes with time and a state in which the intake air temperature TR changes with time when operated in a reference atmosphere. The rate of change in the exhaled energy QR is indicated by SR. By the way, the exhalation energy QR and the intake air temperature TR are obtained by correcting the data shown in FIG. 2 so as to eliminate the influence of the pulsation of the exhalation humidity Hout. Then, the maximum value S1 of the rate of change SR, which is the gradient of the tangent line at the inflection point Q1, and the intake air temperature T1 at this time are stored in advance as reference data, and the air volume and the air flow rate are detected from the data actually detected by operating the cooler. The maximum value S2 of the rate of change SD of the exhaled energy QD obtained by eliminating the influence of the pulsation of humidity and the intake air temperature T at the time when this maximum value S2 occurs.
First, a correction coefficient K using the temperature difference ΔT between T1 and T2 as a parameter is calculated based on 2, and is corrected by multiplying S2 by S2, which is the comparison data, and the deviation S between S3 and S1 is calculated. When * is out of the specified range, it is judged as defective operation.

The correction coefficient K is qualitatively expressed by the following equation (1). In addition, x, y, z, and w represent constants, and e represents the base of natural logarithm. On the other hand, FIG. 7 shows a result obtained by an experiment on the relationship between the temperature difference ΔT and the correction coefficient K.
By obtaining the constants of equation (1) from the relationship shown in FIG. 7, the empirical formula is obtained.

[0017]

(Equation 1)

[0018]

As is apparent from the above description, according to the present invention, whether or not the cooler is operating normally even if the temperature and humidity of the place where the cooler is installed are not constant. Can be determined objectively and easily.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

Fig. 2 Detection signal when Tin is 40 ℃ and cooler is normal
No. and a diagram showing changes in both energies over time

[Fig.3] Detection signal when Tin is 20 ℃ and cooler is normal
No. and a diagram showing changes in both energies over time

[Fig. 4] Condenser fan and radiator at Tin of 30 ° C
Of the detection signal and both energies when the data fan stops
Diagram showing changes over time

[Fig. 5] When the compressor stops at Tin of 30 ° C
Diagram showing the time-dependent change of both detection signals and both energies

FIG. 6 is a diagram showing another operation determination content.

[FIG. 7] The relationship between the correction coefficient and the temperature difference was found by experiments.
Figure showing the result

[Explanation of symbols]

1 Energy sensor (on the exhalation side) 2 Energy sensor (on the intake side) 3 Computer 11 Discharge port 21
Air intake

Claims (1)

(57) [Claims] 1. A cooler operation determination device for detecting the energy of exhaled gas discharged from an outlet of a cooler and judging whether the operating state of the cooler is good or bad based on the detected exhaled energy. The atmosphere detecting means for detecting and the storage means for storing the maximum value of the change rate of the exhaled energy due to the operation from the predetermined atmosphere with time and the intake air temperature at this time as reference data in advance, and the detected actual exhaled energy The maximum value of the change rate with time is converted into comparison data based on the temperature difference between the intake air temperature at this time and the intake temperature of the reference data, and the comparison data and the maximum value of the reference data are compared, and both data are compared. An operation determination device for a cooler, comprising operation determination means for determining the operation state of the cooler as being defective when the deviation is outside a predetermined normal range.