JPH0829026A - Trouble state diagnosing device for absorption tyep cold and hot water device - Google Patents

Abstract

PURPOSE:To eliminate an influence by stained cooling water and carry out a high reliable diagonisis of troubled state when an abnormal state of an absorb ing device is detected under an operation of a troubled state diagnosing device for an absorption type cold and hot water machine. CONSTITUTION:A trouble state-diagnosing device is provided with a group of sensors 7 for measuring a temperature of fluid flowing in a condensor and an absorbing device. The measured data is supplied to a calculation device 8. The calculation device 8 is comprised of circuits 81, 82 for calculating a degree of abnormal state of the condensor and the absorbing device in response to the measured data in the group of sensors 7, a circuit 83 for correcting a degree of abnormal state of the absorbing device in response to a degree of abnormal state in the condensor, and circuit 84 for performing a discrimination for trouble in response to the corrected degree of abnormal state of the absorbing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for diagnosing a failure of an absorption chiller-heater.

[0002]

2. Description of the Related Art As shown in FIG. 3, an absorption chiller-heater has a condenser (11) and a low temperature regenerator (12) arranged on an upper body (1) and an evaporator arranged on a lower body (2). Vessel (21) and absorber (22), burner
High temperature regenerator (3) with built-in (31), high temperature heat exchanger (4), low temperature heat exchanger (5) etc.
By (6), the absorption liquid is absorbed by the high temperature regenerator (3) and the low temperature regenerator (1).
It is circulated between 2) and the absorber (22) to realize a refrigeration cycle or a heat radiation cycle. The cooling water pipe that passes through the evaporator (21) and the condenser (11) has a cooling tower.
Cooling water from (not shown) flows.

By the way, in the absorption chiller-heater, various abnormalities such as contamination of cooling water, abnormal amount of absorbed liquid circulation, abnormal vacuum degree, mixing of absorbing liquid with refrigerant (mixing of refrigerant), etc. may occur. There is When the cooling water becomes dirty, foreign matter such as dust adheres to the inner surface of the cooling water pipe, reducing the heat transfer coefficient, and
Since the cooling effect in (11) and the absorber (22) becomes insufficient, the refrigerating capacity decreases. If the absorbing liquid mixes with the refrigerant,
The boiling point of the refrigerant rises, and as a result, the temperature inside the lower body (2) rises, resulting in deterioration of the capabilities of the evaporator (21) and the absorber (22). Also, when the vacuum level of the lower body (2) drops, the evaporator (21)
And the capacity of the absorber (22) will be reduced.

Therefore, in order to diagnose various abnormalities inside the chiller / heater, various changes in the logarithmic mean temperature difference of various heat exchangers such as the evaporator (21), the absorber (22), and the condenser (11) are monitored. (March 11, 1994, The Japan Society of Mechanical Engineers RC123
See pages 77-82). A temperature sensor such as a thermocouple or thermistor is attached to the inlet / outlet of each heat exchanger in order to measure the fluid temperature at the inlet / outlet of each heat exchanger.

Further, as an index showing the degree of abnormality of each part of the hot and cold water machine, the abnormality degree A expressed by the following equation 2 is defined,
Various types of failures are diagnosed based on the degree of abnormality.

## EQU00002 ## A = (. DELTA.T-.DELTA.Tn) /. DELTA.Tn Here, .DELTA.T is the measured value of the logarithmic average temperature difference, and .DELTA.Tn is the normal value of the logarithmic average temperature difference.

[0006]

In particular, the abnormality degree of the absorber (22) is an important index when detecting various abnormalities.
Since the cooling water is flowing inside the absorber (22), when the cooling water is contaminated, the influence of the cooling water conspicuously appears. However, even in the process in which the chiller-heater continues to operate normally, the contamination of the cooling water gradually progresses with the lapse of operating time. However, it cannot be judged that some abnormality other than the contamination of the cooling water has occurred.

Therefore, in the conventional failure diagnosis based on the abnormality degree of the absorber, it is not possible to distinguish between the contamination of the cooling water and the other causes, and it is possible to detect an abnormality that is a real problem such as refrigerant mixture or a vacuum abnormality. It was difficult. It is an object of the present invention to provide a failure diagnosis device that can eliminate the influence of cooling water contamination when detecting an abnormality in the absorber.

[0008]

A failure diagnosis device for an absorption chiller-heater according to the present invention comprises a sensor means for measuring the temperature of fluid flowing through a condenser (11) and an absorber (22), and a sensor means. Based on the measured data, condenser (11) and absorber (2
The condenser temperature difference data and the absorber temperature difference data, which represent the average temperature difference of the fluid flowing through 2), are calculated, and each temperature difference data is compared with its normal value, and the condenser (11) and the absorber (22 ), An arithmetic circuit for calculating the condenser abnormality data and the absorber abnormality data, and an absorber abnormality correction circuit for correcting the absorber abnormality data according to the size of the condenser abnormality data ( 83) and a failure determination circuit (84) for performing a failure determination based on the corrected absorber abnormality degree data.

In a specific configuration, the temperature difference data is the logarithmic average temperature, and the abnormality degree data is the abnormality degree A defined by the above mathematical expression 2.

[0010]

[Operation] In the absorption chiller-heater, the cooling water is absorbed by the absorber (2
After passing through 2), pass through the condenser (11). Therefore, when cooling water stains occur, not only the absorber (22) but also the condenser
The effect also appears in (11). By the way, in general
Since (22) is arranged in the lower body (2) together with the evaporator (21), the abnormalities of the absorber (22) are complicatedly related to vaporized vapor, absorbing liquid and the like. On the other hand, the condenser (11) is arranged in the upper body (1), and the absorber (22) and the condenser (11) are separated by a partition wall. Therefore, the abnormality of the vacuum of the absorber (22) and the influence of the mixture of the refrigerant do not appear in the condenser (11), and the cause of the abnormality of the condenser (11) is the contamination of cooling water. In other words, the condenser
The degree of abnormality in (11) is an appropriate index that represents the progress of cooling water contamination.

Therefore, in the present invention, the condenser abnormality data and the absorber abnormality data representing the abnormality degrees of the condenser (11) and the absorber (22) are calculated, and the data are calculated according to the magnitude of the condenser abnormality data. It corrects the absorber abnormality data. The correction amount of the data can be calculated, for example, by multiplying the condenser abnormality degree data by a correction coefficient, and in this case, the correction amount is subtracted from the absorber abnormality degree data to obtain the corrected absorber abnormality. Get degree data. Generally, the corrected absorber abnormality degree nAabso is expressed as a function f of the absorber abnormality degree data Aabso (Lc) and the condenser abnormality degree data Acond (Lc) with the refrigeration load Lc at that time as a parameter.
It is expressed as the following Expression 3.

NAabso = f {Aabso (Lc), Aco
nd (Lc)}

FIG. 2 shows that the absorber (2
In the process of increasing the abnormality degree of 2) and the condenser (11), it is shown that the difference between the two represents the corrected abnormality degree of the absorber. This corrected absorber abnormality degree data fluctuates due to an abnormality such as a vacuum abnormality other than cooling water stains or refrigerant mixing, regardless of the progress of cooling water stains, and becomes an appropriate index indicating the degree of these abnormality. .

[0013]

According to the failure diagnosing device for the absorption chiller-heater according to the present invention, when the abnormality of the absorber is judged, the influence of the cooling water stain can be eliminated, and thus the reliability is high. Fault diagnosis is possible.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is applied to a double-effect absorption-type chiller-heater shown in FIG. 3 will be described in detail below with reference to the drawings. FIG. 1 shows the configuration of the failure diagnosis device, and a sensor such as a temperature sensor for measuring the logarithmic mean temperature difference of each heat exchanger such as the condenser (11) and the absorber (22) shown in FIG. group
The measurement data is supplied to an arithmetic unit (8) including a microcomputer.

The arithmetic unit (8) has a circuit (8) for calculating the abnormality degree of the absorber based on the measurement data from the sensor group (7).
1) and a circuit (82) for calculating the degree of abnormality of the condenser are provided. The logarithmic average temperature difference ΔTabs of the absorber (22) is calculated by the following formula 4, and the logarithmic average temperature difference ΔTcon of the condenser (11) is obtained.
d is calculated by the following equation 5, respectively.

[0016]

[Formula 4] ΔTabs = {(Tv_eva-Tco_mid)-(Tw_lo-Tco_i
n)} / ln {(Tv_eva-Tco_mid) / (Tw_lo-Tco_in)}

[0017]

[Expression 5] ΔTcond = {(Tv_cond−Tco_out) − (Tabs_out−T
co_mid)} / ln {(Tv_cond-Tco_out) / (Tabs_out-Tco_mi
d)} where, Tv_eva: vapor temperature of evaporator Tv_cond: vapor temperature of condenser Tw_lo: absorber outlet temperature of absorbing liquid (rare liquid) Tabs_out: condenser outlet temperature of refrigerant Tco_in: cooling water inlet temperature Tco_mid: cooling Water intermediate temperature Tco_out: Cooling water outlet temperature

The logarithmic mean temperature difference ΔT thus obtained
Abnormality Aab of the absorber (22) from abs and ΔTcond
s and the degree of abnormality Acond of the condenser (11) are calculated based on the above equation 2. At this time, the normal value of the logarithmic mean temperature difference between the absorber (22) and the condenser (11) is made into a function or a table in advance with the refrigeration load as a variable.

Further, the arithmetic unit (8) is provided with a circuit (83) for correcting the absorber abnormality degree based on the calculated absorber abnormality degree and condenser abnormality degree. Absorber abnormality correction circuit
(83) is to calculate the correction value xAabs of the absorber abnormality degree with the influence of cooling water contamination removed, based on the following formula (6).

[0020]

## EQU00006 ## xAabs = Aabs-K.Acond Here, K is an experimentally determined coefficient and is normally set to about 1.2. When setting K, for example, the time variation of the abnormalities of the absorber (22) and the condenser (11) is sampled by an experiment, and the correction value xAabs obtained by substituting these data into the above equation 6 is constant. Therefore, a method of determining the value of K by trial and error can be adopted.

For example, when a vacuum abnormality of the lower body (2) occurs, this abnormality does not extend to the upper body (1) and the condenser (11) is not affected by the vacuum abnormality. Further, when the absorbing liquid mixes with the steam in the high temperature regenerator (3) and an abnormality of the mixing of the refrigerant occurs, the steam containing the absorbing liquid passes through the condenser (11), so at that time, temporarily. The logarithmic mean temperature difference of the condenser (11) changes,
The condenser abnormality also changes. However, the absorption liquid that has passed through the condenser (11) moves into the evaporator (21) of the lower body (2) immediately after that, and thereafter circulates through the circulation path of the refrigerant, and the condenser ( There is no return to 11). Therefore, it can be said that, over time, the degree of abnormality of the condenser is not affected by the mixture of the refrigerant. Therefore, according to the above Equation 5, it is possible to obtain the absorber abnormality degree in which the influence of the cooling water contamination is eliminated and the influences of other abnormalities remain.

Absorber abnormality degree xA corrected in this way
abs is supplied to the failure determination circuit (84) shown in FIG. 1, and if necessary, the abnormalities of other heat exchangers and measurement data are taken into consideration to detect abnormalities such as vacuum abnormality and refrigerant mixture. The failure of each part of the water cooler / heater is determined. Failure judgment circuit (8
The determination result according to 4) is output to a display device (9) such as a display or a printer as needed, and is notified to the operator.

According to the above-mentioned failure diagnosis apparatus, even when the cooling water stain progresses due to a change over time, the influence of the cooling water stain can be eliminated, and the abnormality such as the vacuum abnormality or the refrigerant mixture which is a real problem can be detected. Therefore, highly reliable failure determination is realized.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or limiting the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a failure diagnosis device according to the present invention.

FIG. 2 is a graph showing a change in a modified absorber abnormality degree.

FIG. 3 is a diagram showing a configuration of an absorption chiller-heater according to the present invention.

[Explanation of symbols]

 (7) Sensor group (8) Computing device (81) Absorber abnormality degree calculation circuit (82) Condenser abnormality degree calculation circuit (83) Absorber abnormality degree correction circuit (84) Failure determination circuit (9) Display device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Yasuda 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A failure diagnosing device for an absorption chiller-heater having a condenser (11) and an absorber (22) pierced by cooling water pipes, comprising: a condenser (11) and an absorber (22). Based on the sensor means for measuring the temperature of the flowing fluid and the data measured by the sensor means, the condenser (11)
And, the condenser temperature difference data and the absorber temperature difference data representing the average temperature difference of the fluid flowing through the absorber (22) are calculated, and the respective temperature difference data are compared with respective normal values, and the condenser (11) and An arithmetic circuit that calculates the condenser abnormality data and the absorber abnormality data that indicates the abnormality degree of the absorber (22), and the absorber abnormality that corrects the absorber abnormality data according to the size of the condenser abnormality data. A failure diagnosis device for an absorption chiller-heater, comprising a temperature correction circuit (83), and making a failure determination based on the corrected absorber abnormality degree data. 2. The temperature difference data is a logarithmic average temperature difference, and the abnormality degree data is an abnormality degree A defined by the following equation 1 using the measured value ΔT and the normal value ΔTn of the logarithmic average temperature difference as variables. The failure diagnosis device according to item 1. ## EQU1 ## A = (ΔT−ΔTn) / ΔTn