JP3083929B2 - Failure diagnosis system for absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator, and more particularly to a system for detecting a decrease in heat exchange rate of a heat exchange unit constituting a refrigeration cycle and diagnosing a failure of the refrigerator based on the detection. It is.

[0002]

2. Description of the Related Art In an absorption refrigerator, a plurality of heat exchange units, such as a condenser, an evaporator, an absorber, and a regenerator, for exchanging heat between two media are connected to each other by pipes to form one refrigeration unit. A cycle is configured. In particular, a double-effect absorption refrigerator is widely used because of its high refrigeration efficiency (for example, see Japanese Patent Application Laid-Open No. 62-77567 [F25B15 / 00]).

[0003] In an absorption refrigerator, cooling water circulates between the cooling tower and an outdoor cooling tower. In the process, the cooling water absorbs dust and the like in the outside air. When such cooling water passes through a heat exchange unit such as an absorber or a condenser, the heat transfer surface becomes dirty and the heat exchange rate decreases.

[0004] When a failure such as a vacuum abnormality occurs, the leaked gas collects on the lower body. Most of the gas is discharged into the storage chamber by the mechanism that discharges the gas in the lower body into the storage chamber. However, as the pressure in the storage chamber increases, the gas remaining in the lower body increases. In the lower body, since steam flows from the heat transfer tube of the evaporator to the heat transfer tube of the absorber, the non-condensable gas is collected around the heat transfer tube of the absorber, and the absorption of steam in the absorber is performed. Hinder. This results in an abnormal increase in the logarithmic average temperature difference of the absorber.

As described above, when a certain kind of failure occurs,
In one or a plurality of heat exchange units related to the cause of the failure, the logarithmic average temperature difference abnormally rises even though their heat transfer performance is not abnormal.

Therefore, conventionally, various sensors for measuring the temperature, flow rate, concentration, etc. are provided in the input / output section of each heat exchange unit, and the sensor output is monitored, so that the heat exchange unit becomes dirty or abnormal vacuum. Is detected.

In a general heat exchanger, the amount of heat exchange Q
Is expressed as the product of the heat exchange rate K and the logarithmic average temperature difference ΔT. By monitoring the heat exchange rate K, that is, the value K obtained by dividing the heat exchange amount Q by the logarithmic average temperature difference ΔT, the performance due to the contamination of the heat transfer surface is obtained. A drop is detected. This method is also applied to other heat exchange units such as absorbers and condensers, and by knowing the types and combinations of heat exchange units whose heat exchange rates are decreasing, the cause of failures such as abnormal vacuum is diagnosed. I can do it.

[0008]

However, in order to calculate the amount of heat exchange of each heat exchange unit in an absorption refrigerator, a plurality of instruments such as a thermometer and a flow meter must be installed for each. This causes a problem that the equipment becomes large-scale.

An object of the present invention is to use a refrigeration load (a heat exchange amount of an evaporator) instead of a heat exchange amount of each heat exchange unit.
An object of the present invention is to provide a failure diagnosis system capable of accurately detecting a decrease in a heat exchange rate.

[0010]

SUMMARY OF THE INVENTION A failure diagnosis system for an absorption refrigerator according to the present invention comprises a heat exchange unit for detecting a decrease in the heat exchange rate, the temperature of two media flowing through the heat exchange unit. First data processing means for deriving temperature difference data (logarithmic average temperature difference ΔT) corresponding to the difference, and a first storage in which a correspondence relationship between the temperature difference data and the refrigeration load in a normal state of the absorption refrigerator is stored. Means and one or more physical quantities that affect the refrigeration efficiency of the refrigeration cycle, wherein the ratio of the heat exchange amount to the refrigeration load for the heat exchange unit
(E.g., cooling water inlet temperature) stored in a functional relationship with a variable, and based on the functional relationship of the second storing means, the ratio between the heat exchange amount and the refrigeration load at the time of failure diagnosis is determined. Based on the correspondence between the second data processing means for deriving and correcting the refrigeration load using the ratio and the first storage means,
Third data processing means for deriving normal temperature difference data corresponding to the corrected refrigeration load obtained from the second data processing means; normal temperature difference data obtained from the third data processing means; A fourth data processing means for determining the degree of abnormality of the heat exchange unit by comparing the temperature difference data at the time of failure diagnosis obtained from the means, and an output means for outputting a determination result of the fourth data processing means. .

[0011]

When constructing the fault diagnosis system of the present invention,
In advance, when the absorption refrigerator is in a normal state, the temperature difference
The correspondence between the (logarithmic average temperature difference) and the refrigeration load is tabulated or functioned and stored in the first storage unit.

The ratio between the heat exchange amount and the refrigeration load for the heat exchange unit is functioned by using one or a plurality of physical quantities that affect the refrigeration efficiency of the refrigeration cycle as variables.
The function relation is stored in the second storage means. For example, if the cooling water inlet temperature is a variable, the refrigeration efficiency increases as the cooling water inlet temperature decreases.Therefore, when the refrigeration load is constant, the heat input to the absorption chiller decreases as the cooling water inlet temperature decreases. In addition, the amount of heat exchange of each heat exchange unit is similarly reduced. At this time, the degree of reduction in the heat exchange amount differs for each heat exchange unit. This is because the ratio of the heat input and the refrigeration load to the heat exchange amount of each heat exchange unit differs for each heat exchange unit. Therefore, for each heat exchange unit, the ratio between the heat exchange amount and the refrigeration load can be represented by a function having the cooling water inlet temperature as a variable, for example, a linear expression.

At the time of failure diagnosis, the temperature difference and the flow rate of the cold water passing through the evaporator are measured, and the refrigeration load is calculated from the measured data. Further, temperature difference data (logarithmic average temperature difference ΔT) of the target heat exchange unit is measured.

By the way, when a refrigeration load is used in place of the heat exchange amount when detecting a decrease in the heat exchange rate, for example, if the cooling water inlet temperature decreases despite the refrigeration load being constant, the above-described case will be described. Since the amount of heat exchange decreases as described above, the amount of heat exchange and the refrigerating load do not correspond to each other, and it is impossible to accurately detect a decrease in the heat exchange rate.

Therefore, in the present invention, the above problem is solved by performing a correction for changing the refrigeration load by the change rate of the heat exchange amount. That is, for the target heat exchange unit, the physical quantity at that time (for example, cooling water inlet temperature) is input to the function of the second storage means,
The ratio between the heat exchange amount and the refrigeration load is derived. If the ratio is multiplied by the refrigeration load to correct the refrigeration load, the corrected refrigeration load has a value excluding the effect of the fluctuation of the refrigeration efficiency due to the cooling water inlet temperature.

Then, based on the correspondence of the first storage means,
Deriving temperature difference data corresponding to the corrected refrigeration load. The temperature difference data at normal time and the temperature difference data at fault diagnosis are
Since the data under the same heat exchange amount excluding the effect of thermal efficiency, comparing these temperature difference data,
The degree of abnormality of the heat exchange unit can be accurately determined. When the type and combination of the heat exchange units having a reduced degree of abnormality are found, it is possible to diagnose the cause of the failure based on this.

[0017]

According to the failure diagnosing system for an absorption refrigerator according to the present invention, a decrease in the heat exchange rate can be accurately detected by using a refrigeration load that can be easily measured. Fault diagnosis is possible.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a double effect absorption refrigerator will be described in detail with reference to the drawings. As shown in FIG. 1, the absorption refrigerator uses water as a refrigerant and a lithium bromide (LiBr) solution as an absorption liquid.
And a lower body (2) comprising an evaporator (21) and an absorber (22); a high temperature regenerator (3) incorporating a burner (31); An exchanger (4), a low-temperature heat exchanger (5) and the like are connected to each other by piping. In addition, necessary sensors (not shown) are provided in the medium input / output unit of these multiple devices.
Are attached, and various physical quantities described later are measured.

Low-temperature cooling water supplied from a cooling tower (not shown) first passes through an absorber (22),
The cooling water, which has passed through the condenser (11) and thus has increased in temperature, is returned to the cooling tower again. The high-temperature cold water from the indoor unit (not shown) passes through the evaporator (21), whereby the low-temperature cold water cooled is supplied to the indoor unit.

FIG. 2 shows the configuration of a system for performing a failure diagnosis on the condenser (11) and the evaporator (21). The sensor group (6) includes a pressure in the upper body (1) shown in FIG.
The refrigerant outlet temperature of (11), the pool temperature Ta_out of the absorbent in the absorber (22), and the spray temperature Ta_ of the absorbent in the absorber (22)
in, outlet temperature Tco of the cooling water flowing out of the condenser (11)
_Out, the cooling water intermediate temperature Tco_mid between the absorber (22) and the condenser (11), the inlet temperature Tco_in of the cooling water supplied to the absorber (22), and the chilled water outlet temperature Tc_o of the evaporator (21).
ut, a chilled water inlet temperature Tc_in, and a pressure gauge, a thermometer, and a flow meter for measuring the chilled water flow rate Vc, respectively.

In the present embodiment, the inlet temperature of the cooling water supplied to the absorber is adopted as a physical quantity that affects the refrigeration efficiency of the refrigeration cycle. The reason that the refrigeration efficiency is improved by lowering the cooling water inlet temperature can be explained by, for example, when the refrigeration cycle is represented on a During diagram, the entire refrigeration cycle loop moves to the low pressure and low temperature side. . Here, a specific trial calculation will be made as to how much the refrigeration efficiency is improved by lowering the cooling water inlet temperature.

When the cooling water inlet temperature decreases while the refrigerator is operating in a certain state, the cooling water intermediate temperature and the outlet temperature also decrease by substantially the same amount. This is because the amount of heat released to the cooling water hardly changes even if the temperature of the cooling water changes. Therefore, a decrease in the temperature of the cooling water will appear separately in two places, the absorber and the condenser.

When there is no significant change in the refrigerating capacity of the refrigerator, the vapor pressure in the lower body hardly changes, whereas in the absorber, the temperature of the absorbing liquid decreases due to a decrease in the cooling water temperature. For example, lower body pressure 6 mmHg, cooling water inlet temperature 30
If the cooling water temperature is lowered by 4 degrees in the case of the absorption liquid concentration of 55% and the dilution liquid temperature of 35 degrees, the absorption liquid concentration changes to 53% and the dilution liquid temperature of 31 degrees while the lower body pressure is kept constant. As a result, the low-temperature, low-concentration absorbing liquid from the absorber flows to the high-temperature regenerator, so that the temperature and concentration of the high-temperature regenerator change in a direction of decreasing.

On the other hand, in the condenser, the cooling water inlet temperature is 30
In the case of degrees, when the intermediate temperature is 34 degrees and the outlet temperature is 36 degrees, if the inlet temperature decreases by 4 degrees, the intermediate temperature and the outlet temperature decrease by the same amount to 30 degrees and 32 degrees, respectively. As a result, the condensation temperature of the refrigerant in the condenser drops by about 4 degrees, so that the pressure of the upper body drops from about 60 mmHg to 50 mmHg. When the pressure in the upper body decreases, the boiling point of the absorbent in the low-temperature regenerator decreases. At the same time, the absorption liquid has a concentration of 61% and a concentrated liquid temperature of 90 degrees, including the effects of a decrease in the concentration of the absorption liquid generated in the absorber and a decrease in the circulation amount of the absorption liquid described below.
The concentration decreases to 60% and the temperature to 85 degrees, respectively.

When the temperature (boiling point) of the absorbent concentrate decreases, the condensation temperature of the refrigerant vapor from the high-temperature regenerator condensing in the heat transfer tube of the low-temperature regenerator decreases from 92 degrees to 87 degrees. When the condensation temperature decreases, the vapor pressure in the low-temperature regenerator becomes 550 mmHg
It falls to 450 mmHg. Because of the steam flow resistance between the low-temperature regenerator and the high-temperature regenerator, the steam pressure of the high-temperature regenerator and the low-temperature regenerator will not be the same, but the low-temperature regenerator will have a low steam pressure. The steam pressure in the regenerator also drops, from 670 mmHg to 550 mmHg.

Due to a decrease in the vapor pressure, a decrease in the concentration of the absorbing solution, and a decrease in the amount of the circulating absorbing solution, the intermediate solution of the absorbing solution in the high-temperature regenerator has a concentration of 60% and a temperature of 152 degrees, a concentration of 59% and a temperature of 1%.
It drops to 45 degrees. As described above, when the pressure of the high-temperature regenerator and the upper body pressure decrease, the pressure difference between the high-temperature regenerator and the upper body pressure also decreases from 610 mmHg to 500 mmHg.

When the difference in the level of the absorbing liquid between the two regenerators is pushed up by the pressure difference, the absorbing liquid circulates from the high-temperature regenerator through the high-temperature heat exchanger to the low-temperature regenerator. The amount of liquid circulation will be reduced. With the difference of 4 degrees of cooling water inlet temperature, the circulating volume of the dilute absorbing liquid is about 0.84%
The lower it is.

As a result, to maintain the same refrigeration capacity,
Since it is necessary for the absorbing liquid to absorb the same amount of refrigerant vapor in the absorbing liquid, when the cooling water temperature decreases, the concentration difference between the absorbing liquid concentrated liquid and the diluted liquid becomes 6% (= 61% -55%) to 7%. (= 60% -5
3%). At this time, the temperature of the diluted absorbent before entering the high-temperature regenerator, which has been heated from the low-temperature heat exchanger through the high-temperature heat exchanger, decreases from 125 degrees to 118 degrees.

Hereinafter, a trial calculation will be made for 1 kg of refrigerant vapor absorbed by the absorber. The heating amount in the high-temperature regenerator
When the cooling water inlet temperature is 30 degrees, the concentration is 55% and the temperature is 125.
Is heated to produce 9.32 Kg of an intermediate liquid having a concentration of 60% and a temperature of 152 ° C. and 1 Kg of steam having a pressure of 670 mmHg.
7.75 Kcal is the required heating amount.

Similarly, when the cooling water inlet temperature is 26 ° C., 8.57 kg of a diluted liquid having a concentration of 53% and a temperature of 118 ° C.
9.70 kg of an intermediate liquid having a temperature of 145 degrees and a pressure of 55%.
The required heating amount is 620.78 Kcal as the enthalpy difference because the pressure is 0 kgHg steam 1 kg.

Therefore, when the cooling water temperature drops 4 degrees from 30 degrees to 26 degrees, the efficiency (refrigeration capacity / heat input) of the refrigerator becomes
Improve by about 4%. However, in practice, the decrease in the refrigerant condensing temperature slightly reduces the amount of refrigerant vapor absorbed by the absorber, so that the efficiency is slightly improved.

As described above, the refrigeration efficiency is improved with a decrease in the cooling water inlet temperature. Therefore, in this embodiment, the cooling water inlet temperature is used as a variable and the heat of the condenser (11) and the absorber (22) is changed. The ratio between the replacement amount and the refrigeration load is functioned in advance,
By correcting the refrigeration load based on the function, an appropriate degree of abnormality is calculated.

The arithmetic processing circuit (7) shown in FIG. 2 is composed of a microcomputer, and has the following nine calculation units (71) to (79).
It has. The condenser logarithmic average temperature difference calculation unit (71) calculates the logarithmic average temperature difference of the condenser from the upper body pressure, the refrigerant outlet temperature, the cooling water outlet temperature, and the cooling water intermediate temperature. The difference calculation unit (72) calculates the logarithmic average temperature difference of the absorber from the absorption liquid pool temperature, the absorption liquid spraying temperature, the cooling water outlet temperature, and the cooling water inlet temperature.

Specifically, the logarithmic average temperature difference ΔT of the absorber
(abso) is calculated by the following equation (1), and the logarithmic average temperature difference ΔT (cond) of the condenser is calculated by the following equation (2).

[0035]

ΔT (abso) = (Ta_in-Tco_mid-Ta_out + Tco_in) / ln {(Ta_in-Tco_mid) / (Ta_out-Tco_in)}

[0036]

ΔT (cond) = (Tcond−Tco_out−Tcond + Tco_mid) / ln {(Tcond−Tco_out) / (Tcond−Tco_mid)}

Here, Tcond is the saturated vapor temperature in the condenser, and is determined from the pressure in the upper body (1).

The refrigeration load calculator (75) of the arithmetic processing circuit (7)
Calculates the refrigeration load Lc from the chilled water outlet temperature, the chilled water inlet temperature, and the chilled water flow rate based on the following equation (2).

[0039]

Lc = Vc (Tc_out−Tc_in)

In the arithmetic processing circuit (7) shown in FIG. 2, the refrigeration load correction unit (73) for the condenser and the refrigeration load correction unit (74) for the absorber are each provided with a refrigeration load based on the cooling water inlet temperature. In each correction unit, the ratio Q / Lc between the heat exchange amount Q and the refrigeration load Lc is stored in advance in the form of a function using the cooling water inlet temperature Tco_in as a variable. .

FIG. 3 shows each of the absorber and the condenser.
It shows the results of actual measurement of the relationship between the cooling water inlet temperature Tco_in and the ratio Q / Lc, and it can be seen that any of them can be accurately expressed by a linear equation. Therefore, assuming that the linear equation shown in FIG. 3 is modified to be a correction coefficient for the refrigeration load Lc, the corrected refrigeration loads Lc ′ (abso) and Lc ′ (cond) for the absorber and the condenser are respectively expressed by the following equation (4). And equation (5).

[0042]

Lc ′ (abso) = Lc {1 + KTco (abso) · (Tco_in−BTco (abso))}

Lc ′ (cond) = Lc {1 + KTco (cond) · (Tco_in−BTco (cond))}

Here, KTco (abso), BTco (abs
o), KTco (cond) and BTco (cond) are specific coefficients of the absorber and the condenser, respectively, and are experimentally obtained.

The normal logarithmic average temperature difference calculating section (76) and the normal logarithmic average temperature difference calculating section (77) of the condenser shown in FIG. The correspondence relationship with the refrigeration load is tabulated, and the logarithmic average temperature difference in a normal state is derived based on the corrected refrigeration load.

FIG. 4 shows the refrigeration load Lc and the logarithmic average temperature difference ΔT.
Is represented by a qualitative graph, and the solid line corresponds to the table stored in the logarithmic average temperature difference calculation unit in the normal state. This relationship is obtained by actually measuring the logarithmic average temperature difference while changing the refrigeration load in a normal operation state for each of the heat exchange unit to be subjected to the failure diagnosis, and in this embodiment, for each of the condenser and the absorber. Created in advance.

The logarithmic mean temperature difference calculation section (7
6) searches the table based on the corrected refrigeration load obtained from the refrigeration load correction unit (73) in FIG. 1, and derives a logarithmic average temperature difference corresponding to the corrected refrigeration load. The logarithmic average temperature difference calculation unit (77) in the normal state of the absorber searches the table based on the corrected refrigeration load obtained from the refrigeration load correction unit (74) in FIG. Derive the corresponding log average temperature difference.

The condenser abnormality degree calculation section (78) and the absorber abnormality degree calculation section (79) calculate the degree of abnormality from the logarithmic average temperature difference at the time of failure diagnosis and at the time of normal operation, respectively. Here, in the graph shown in FIG. 4, the degree of abnormality A is obtained by converting the logarithmic average temperature difference ΔT (Lc) in the abnormal state into a logarithmic average temperature difference ΔTs in the normal state.
This is normalized by (Lc), and is defined by Equation 6 below.

[0048]

A = {ΔT (Lc) −ΔTs (Lc)} / ΔTs (Lc)

In Equation 6, the logarithmic average temperature difference between the abnormal state and the normal state is a value at the same refrigeration load Lc. When deriving the temperature difference, it is appropriate to use the corrected refrigeration load as a reference.

Then, the abnormalities A (abso) and A (cond) of the condenser and the absorber are calculated by using the logarithmic average temperatures in the normal state shown by the above equations 4 and 5, respectively, by the following equations 7 and Calculated by 8.

[0051]

A (abso) = {ΔT (Lc (abso)) − ΔTs (Lc ′ (abso)} / ΔTs (Lc ′ (abso)

A (cond) = {ΔT (Lc (cond)) − ΔTs (Lc ′ (cond)} / ΔTs (Lc ′ (cond)

The output device (8) shown in FIG. 2 calculates the abnormality degree of the condenser and the absorber obtained from the condenser abnormality degree calculation section (78) and the absorber abnormality degree calculation section (79) as numerical data or as reference data. When the value is exceeded, an alarm is output to an operation monitoring room or the like.

According to the above failure diagnosis system, the condenser
Without measuring the heat exchange amount of (11) and the absorber (22), the degree of abnormality can be calculated by using the easily measured refrigeration load Lc. By using the method, the influence of the refrigeration efficiency is excluded, so that an accurate degree of abnormality can be obtained, thereby enabling a highly reliable failure diagnosis.

In the above embodiment, the cooling water inlet temperature is employed as a physical quantity affecting the refrigeration efficiency. However, the cooling water flow rate, the cooling water intermediate temperature between the absorber and the condenser, the condenser Outlet temperature of the cooling water flowing out of the tank, concentration of the absorbing liquid supplied to the absorber, flow rate, temperature, pressure inside the absorber,
It is also possible to adopt the pressure in the condenser, the outlet temperature of the cold water flowing out of the evaporator, or the like. It is also possible to combine a plurality of physical quantities selected from these.

For example, the intermediate temperature and outlet temperature of the cooling water are
Since it mainly affects the condensation temperature in the condenser and the upper body pressure, the efficiency is changed by affecting the pressure of the high-temperature regenerator and the amount of circulating absorbent.

As for the flow rate of the cooling water, when the cooling water flow rate increases, the temperature of the absorbing liquid in the absorber decreases even when the cooling water inlet temperature is constant. Further, since the cooling water intermediate temperature and the outlet temperature decrease, the condensing temperature also decreases. Therefore, as the flow rate of the cooling water increases, the efficiency of the refrigerator increases. In this case, the influence on the condenser is greater than when the cooling water inlet temperature changes.

With respect to the concentration of the absorbing solution, if the heat input to the regenerator is the same and the concentration of the absorbing solution (for example, the concentration of the concentrated solution) increases, if the circulation amount of the absorbing solution and the temperature of the absorbing solution are the same, Since the amount of water vapor absorption increases, the refrigeration capacity increases, and the refrigeration efficiency improves.

Regarding the circulating amount of the absorbing solution, when the amount of heat input to the regenerator is the same, if the circulating amount of the absorbing solution increases, if the temperature and the concentration of the absorbing solution are the same, the amount of absorbing water vapor of the absorbing solution increases. The refrigerating capacity is increased, and the refrigerating efficiency is improved.

Changes in the temperature of the absorbing solution (the temperature of the concentrated solution / the diluted solution in the absorber) affect the efficiency for the same reason as in the case of the cooling water inlet temperature. Further, when the temperature of the absorbing solution in the low-temperature regenerator increases, the concentration of the concentrated solution increases if the upper body pressure is the same, so that the amount of water vapor absorbed by the absorber increases, and the efficiency improves.

When the inlet / outlet temperature of the cold water rises or the flow rate of the cold water increases, the amount of refrigerant evaporated in the evaporator increases, so that the lower body pressure increases. As a result, the capacity of the absorber to absorb the vapor of the absorbing liquid is increased, and the refrigeration efficiency is improved.

Therefore, if one or a plurality of physical quantities are selected from the above-mentioned plurality of physical quantities and the ratio between the heat exchange quantity and the refrigeration load for the heat exchange unit is expressed as a function, a function based on the function is obtained. By compensating the refrigeration load,
An appropriate degree of abnormality can be calculated.

The description of the above embodiments is for the purpose of illustrating the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof. Further, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

For example, in the above-described embodiment, the failure diagnosis is performed for the condenser (11) and the absorber (22). However, the present invention is not limited to this, and the present invention may be applied to a high-temperature heat exchanger (4) or a low-temperature heat exchanger (4). Heat exchanger
Needless to say, the same can be applied to other heat exchange units such as (5). In addition, as the degree of abnormality,
Various evaluation values reflecting the reduction in the heat exchange rate of the heat exchange unit can be employed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an absorption refrigerator in which the present invention is to be implemented.

FIG. 2 is a block diagram illustrating a configuration of a failure diagnosis system.

FIG. 3 is a graph showing a ratio between a heat exchange amount and a refrigerating capacity with a cooling water inlet temperature as a variable.

FIG. 4 is a graph comparing a logarithmic average temperature difference between a normal state and an abnormal state.

[Explanation of symbols]

 (11) Condenser (12) Low temperature regenerator (21) Evaporator (22) Absorber (3) High temperature regenerator (4) High temperature heat exchanger (5) Low temperature heat exchanger (6) Sensor group (7) Calculation Processing circuit (8) Output device

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masahiro Furukawa 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP-A-4-64876 (JP, A) JP-A-Hei 2-130363 (JP, A) JP-A-56-146966 (JP, A) JP-A-61-162766 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 F25B 15/00 306 F25B 49/04

Claims (2)

(57) [Claims] 1. An absorption refrigerator in which a plurality of heat exchange units, such as a condenser, an evaporator, and an absorber, are connected to each other by piping to form one refrigeration cycle, and the heat exchange rate of each heat exchange unit is reduced. Is a system for diagnosing a failure of a refrigerator based on a temperature difference data corresponding to a temperature difference between two media flowing in the heat exchange unit, wherein the heat exchange unit detects a decrease in a heat exchange rate. First data processing means for deriving the temperature of the absorption type refrigerator, first storage means for storing the correspondence between the temperature difference data and the refrigeration load of the absorption chiller during normal operation, and the heat exchange amount and refrigeration for the heat exchange unit. A failure diagnosis is performed based on a second storage unit in which a ratio with a load is stored as a functional relationship with one or a plurality of physical quantities as variables as variables that affect the refrigeration efficiency of the refrigeration cycle. A second data processing means for deriving a ratio between the heat exchange amount at the time and the refrigeration load and correcting the refrigeration load according to the ratio; Data processing means for deriving normal temperature difference data corresponding to the corrected refrigeration load, normal temperature difference data obtained from the third data processing means, and failure diagnosis obtained from the first data processing means 4. An absorption refrigeration system comprising: fourth data processing means for determining the degree of abnormality of the heat exchange unit by comparing the temperature difference data of the above; and output means for outputting the determination result of the fourth data processing means. Machine failure diagnosis system. In the second storage means, the physical quantities affecting the refrigeration efficiency of the refrigeration cycle include the inlet temperature and flow rate of the cooling water supplied to the absorber, and the cooling water flowing between the absorber and the condenser. Temperature, outlet temperature of the cooling water flowing out of the condenser, concentration, flow rate, temperature of the absorbing liquid supplied to the absorber,
The fault diagnosis system according to claim 1, wherein one or more physical quantities selected from among a pressure in the absorber, a pressure in the condenser, and an outlet temperature of the cold water flowing out of the evaporator are set.