JPH071136B2 - Absorption chiller / heater vacuum degree diagnostic device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a diagnostic device for an operating state of an absorption chiller-heater, and more specifically, to measure the temperature of each part of the state of the vacuum degree of the chiller-heater. The present invention relates to a vacuum degree diagnostic device for an absorption chiller-heater.

[Conventional technology]

In general, an absorption chiller-heater has an evaporator that evaporates a liquid refrigerant supplied from a condenser and exchanges heat with the cold-hot water that flows through the cold-hot water pipe, and the refrigerant vapor evaporated in this evaporator is cooled by cooling water. The cooling water pipe is made to come into contact with the absorbing liquid to absorb the absorbing liquid. Then, the dilute solution obtained by absorbing the refrigerant vapor flowing out from the absorber is heated to be separated into the refrigerant vapor and the absorbing liquid, which are circulated and supplied to the condenser and the absorber, respectively.

In order to operate the absorption chiller-heater configured as described above with high efficiency, it is necessary to appropriately diagnose the degree of vacuum in the absorption chiller-heater to maintain the high degree of vacuum.

Conventionally, as a method of diagnosing the degree of vacuum, a pressure detector (compound meter, manometer, pressure sensor, etc.) is attached to the evaporator or absorber through a detection valve, and the inside of the connecting pipe is evacuated and then detected. It is known to open the pressure valve to guide the internal pressure of the chiller / heater and judge from the value indicated by the detector. As another method, the refrigerant liquid temperature of the evaporator is measured, and the saturated vapor pressure of the refrigerant is calculated (or a diagram) from the temperature, the absorber outlet temperature of the absorbing liquid, and the liquid Is sampled (using a vacuum pump from the sampling valve) to measure the concentration, and the saturated vapor pressure of the solution is calculated (or a diagram of the solution) from the concentration and temperature to compare it with that obtained. I was diagnosing the degree of vacuum.

[Problems to be Solved by the Invention]

However, the conventional known techniques have the following problems.

(1) Skill required for work.

(2) Highly accurate and expensive measuring equipment and equipment such as vacuum pumps are required. In addition, it is difficult to carry in and out these devices to the site.

(3) Since the valves (pressure detection and liquid sampling) of the refrigerator are opened and closed during the work, there is a risk of breaking the vacuum.

(4) In general, the solution of the absorption chiller-heater is highly corrosive, which may damage the equipment or cause corrosion (rust) due to scattering of the solution during work.

(5) The time and cost required for inspection are large.

An object of the present invention is to diagnose the vacuum state of an absorption chiller-heater,
An object of the present invention is to provide a vacuum degree diagnostic device that can be accurately performed without using a pressure gauge or a densitometer based only on temperature information of the components of the chiller / heater and the pipe system connecting each element.

[Means for Solving the Problems]

In order to solve the above problems, the present invention provides an outlet temperature T of cold / hot water.
b, evaporation temperature Te of the liquid refrigerant in the evaporator, temperature Td of the outlet of the absorption liquid flowing out from the absorber, temperature detectors that detect the inlet temperature Ta and the outlet temperature Tc of the cooling water, and the evaporation temperature Te and the outlet of the absorption liquid. The difference Tda between the temperature Td and the cooling water inlet temperature Ta and the difference Tdc between the absorption liquid outlet temperature Td and the cooling water outlet temperature Tc are used as the judgment factors, respectively, and based on the detected cold / hot water outlet temperature Tb and the cooling water inlet temperature Ta. Judgment reference value calculating means for obtaining a judgment reference value of each judgment element in a predetermined normal operating state, and a present value of the judgment element based on the detected temperature of each part, and the present value and the judgment Another object of the present invention is to provide a degree-of-vacuum diagnostic device including a degree-of-vacuum determination means for determining whether the degree of vacuum is good by comparing reference values.

[Action]

Between the evaporation temperature Te of the liquid refrigerant of the absorption chiller / heater and the vacuum degree, between the temperature difference Tda between the absorption fluid outlet temperature Td and the cooling water inlet temperature Ta and the vacuum degree, and between the absorption fluid outlet temperature Td and the cooling water. Outlet temperature
There is a strong correlation between the temperature difference Tdc of Tc and the degree of vacuum. Therefore, the present invention diagnoses the degree of vacuum by using these three items as judgment factors.

Further, the judgment reference value for judging the quality of the vacuum degree based on the above-mentioned judgment factors is related to the operating state (load state) of the absorption chiller-heater. Also, the operating state is the cold / hot water outlet temperature Tb
Is correlated with the cooling water inlet temperature Ta, the value of the judgment element in the operating state at the normal vacuum degree is obtained based on these detected temperatures, and this is used as the judgment reference value.

Therefore, according to the present invention, based on the temperature of each part detected by the temperature detector, the present value of the judgment element and its judgment reference value are obtained, and the quality of the vacuum degree is judged by comparing them. .

This judgment is made for each of the above-mentioned three judgment elements, and a comprehensive judgment is made based on their quality.

In this case, since the degree of influence of the vacuum degree on the quality determination is different for each determination element, it is desirable to weight the comparison result of each determination element for determination.

〔Example〕

Hereinafter, the present invention will be described based on examples. FIG. 1 shows a schematic configuration diagram of a vacuum degree diagnostic device 30 according to an embodiment of the present invention.
The vacuum degree diagnostic device 30 of the present embodiment includes a movable main body 31 and temperature detectors 32a to 32e for detecting the temperature of each part of the absorption chiller-heater. The main body 31 is a judgment reference value calculator 33,
A current value calculator 34, a comparison calculator 35, a weight calculator 36,
The weighted total value comparison calculator 37 and the display 38 are included. The degree-of-vacuum determination means is formed by the comparison calculator 35, the weight calculator 36, and the weighted aggregate value comparison calculator 37. Further, the temperature detectors 32a to 32e are the connectors 39 provided on the main body 31.
a to 39e, each connected with a flexible wire, and each connector 39a to 39e.
Are appropriately connected to the judgment reference value calculator 33 and the current value calculator 34.

Hereinafter, the detailed configuration of each of the arithmetic units will be described together with the operation. The absorption chiller-heater shown in FIG. 2 will be described as an example of the diagnosis target.

First, the absorption chiller-heater shown in FIG. 2 will be described. The dilute solution that has absorbed the refrigerant is heated in the re-ejector 1 and guided to the separator 2, where it is separated into refrigerant vapor and absorbing liquid. This absorbing liquid is a medium-concentrated solution containing a non-evaporated refrigerant, and is guided to the low temperature regenerator 3 via the first heat exchanger 9, where the refrigerant is further evaporated and separated. The concentrated solution flowing out from the low temperature regenerator 3 is injected into the top of the absorber 6 via the second heat exchanger 8.

On the other hand, the refrigerant vapor separated by the separator 2 is guided to the condenser 4 via the low-temperature regenerator 3, where heat is taken by the cooling water flowing in the cooling water pipe 18 and condensed. . The liquid refrigerant produced by condensation is guided to the top of the evaporator 5 and flows down to the surface of the cold / hot water pipe 20 arranged inside the evaporator 5. As a result, the liquid refrigerant is evaporated, and the heat of evaporation is exchanged with the cold / hot water flowing in the cold / hot water pipe 20.

The refrigerant vapor evaporated in the evaporator 5 is guided to the absorber 6,
The absorption liquid (concentrated solution) flowing down on the surface of the cooling water pipe 18 arranged in the absorber 6 is contacted and absorbed. The absorption heat generated at this time is removed by the cooling water. The dilute solution obtained by absorbing the refrigerant in the absorber 6 is extracted by the solution circulation pump 7 and returned to the regenerator 1 via the first and second heat exchangers 8 and 9.

The inside of the absorption chiller-heater configured as described above is maintained at a high degree of vacuum, but when the degree of vacuum decreases, the following temperature change phenomenon occurs.

The evaporation temperature Te of the evaporator 5 rises as the degree of vacuum decreases.

In a chiller-heater that does not have a refrigerant pump that recirculates unevaporated liquid refrigerant flowing down to the bottom of the evaporator 5 to the top, when the amount of refrigerant evaporation in the evaporator 5 decreases, the amount of unevaporated liquid refrigerant increases. . This liquid refrigerant flows into the absorber 6 and is directly mixed with the absorbing liquid to generate heat of dilution. Since this heat is not in contact with the cooling water pipe 18, it has no opportunity to be thrown into the cooling water and raises the temperature of the dilute solution exiting the absorber 6. Therefore, the temperature difference between the absorber outlet temperature Td of the dilute solution and the cooling water inlet temperature Ta is Tda (= Td
-Ta) increases as the degree of vacuum decreases.

For the same reason as above, and the amount of heat removed to the cooling water decreases due to the reduction in the refrigeration capacity accompanying the decrease in the degree of vacuum, and due to the synergistic action with the decrease in the cooling water outlet temperature Tc, the absorber outlet temperature Td of the diluted solution Temperature difference from outlet temperature Tc Tdc (= Td-T
c) becomes larger as the degree of vacuum decreases. Therefore, the degree of vacuum can be diagnosed by using these three items as judgment factors.

Of the temperatures of each part required for the above judgment, the cooling water inlet temperature Ta
Is the temperature detector 32a, the cold / hot water outlet temperature Tb is the temperature detector 32b, the cooling water outlet temperature Tc is the temperature detector 32c, the absorption liquid outlet temperature Td is the temperature detector 32d, and the evaporation temperature Te is the temperature detector. It is designed to detect each by 32e. These detectors 32a to 32d are attached to pipes or the like so as to measure corresponding temperatures.

Of the detected temperatures, the cooling water inlet temperature Ta and the cold / hot water outlet temperature Tb are input to the judgment reference value calculator 33, and the judgment reference values corresponding to the judgment elements shown in Table 1 are obtained.

The judgment reference values J _{1 to} J ₃ are the values of the judgment factors that are considered to be the case under the normal vacuum state, and since the values also change depending on the load condition and the like, the above two temperatures Ta And Tb, and based on a predetermined calculation formula stored in the ROM.

FIG. 4 shows an example of actual measurement of changes in each judgment element before and after the occurrence of vacuum break.

On the other hand, the detected and input cooling water inlet temperature Ta, cooling water outlet temperature Tc, diluted solution absorber outlet temperature Td, and evaporator temperature Te
Based on the above, the current value calculator 34 calculates the current temperature difference (current value) for each of the judgment elements shown in Table 2.

The calculated judgment reference value and current value are input to the comparison calculator 35 as shown in the flowchart of FIG.
The comparison calculator 35 compares the judgment reference value and the current value for each judgment element, and judges whether the degree of vacuum in the judgment element is good or bad. When the current value is smaller than the judgment reference value, it is judged to be good (EGV), and when it is larger, it is judged to be defective (ELV), and the comparison result of these sizes is output to the weight calculator 36. The weight calculator 36 has two judgment frames (specifically, registers) of good (EGV) and bad (ELV) for each judgment element, and the EGV or ELV corresponding to the comparison result of the comparison calculator 35.
The weight values W ₁ , W ₂ , and W ₃ are set in one of the judgment frames. This weight value represents the degree of influence of each judgment element on the vacuum degree judgment, and is preset and stored so that the total becomes 1 or 100%. The weighted aggregate value comparison calculator 37 takes in the contents separately from each judgment frame of the weight calculator 36 for each good (EGV) or defective (ELV), and totals those values. Then compare the EGV aggregate value with the ELV aggregate value,
If the total value of ELV is large, it is determined that the degree of vacuum is poor, and the determination signal is output to the display unit 38, and if the total value of EGV is large, the determination signal that the degree of vacuum is good is output to the display unit 38. Note that the display 38 may display the calculated aggregate values of EGL and EGV. Further, the display 38 may be a liquid crystal display or a lamp display.

When a vacuum degree defect is diagnosed, the signal can be used to operate the air extraction device. Further, in the chiller-heater having the refrigerant pump, even if the refrigerant evaporation amount in the evaporator 5 decreases, the diluted solution and the refrigerant liquid do not mix, and the absorbed heat amount in the absorber 6 simply decreases. Therefore, contrary to the above phenomenon, the temperature at the outlet of the absorber
Td decreases. As described above, the diluted solution absorber outlet temperature Td exhibits the opposite phenomenon depending on whether the refrigerant pump is provided or not. That is, the inequality signs of the judgment factors Tda and Tdc may be reversed.

In addition, in the above-described embodiment, the case where the degree of vacuum is determined by the three determination elements has been described, but it is also possible to perform determination by any one or a combination of two of the three determination elements. In that case, the accuracy and reliability of the vacuum degree determination may be reduced accordingly.

In addition, although the above-described embodiment shows the double-effect absorption chiller-heater as a diagnosis target, it is also applicable to a single-effect absorption chiller-heater by replacing the calculation formula for calculating the judgment reference value.

As described above, whether the vacuum degree of the absorption chiller-heater is good or bad, without using a densitometer or pressure gauge,
It is possible to make a diagnosis by detecting the temperature, and it is not necessary to provide a special device for the water cooler in advance. Further, the work required for the diagnosis is only to attach the five temperature detectors attached to the mobile vacuum degree diagnostic device to the absorption chiller-heater to be diagnosed, and the work time is short. Further, the accuracy of the diagnosis is high because the diagnosis is made by combining a plurality of judgment elements.

〔The invention's effect〕

According to the present invention, a temperature detector, a judgment reference value calculation means for calculating a judgment reference value based on the detected temperature, a current value calculation means for calculating a current value based on the detected temperature, and a calculation The vacuum degree judging means for judging the degree of vacuum based on the determined reference value and the present value is used to diagnose the degree of vacuum only from the temperature of the components of the absorption chiller-heater and the pipe system connecting each element. Therefore, there is an effect that diagnosis can be performed accurately without using a pressure gauge or a densitometer.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing a state in which the diagnostic device of FIG. 1 embodiment is attached to an absorption chiller-heater, and FIG. FIG. 4 is a flow chart showing the procedure of the vacuum degree diagnosis of the example, and FIG. 4 is a diagram showing changes in each judgment element when the vacuum degree is intentionally given to the absorption chiller-heater. 1 ... Regenerator, 4 ... Condenser, 5 ... Evaporator, 6 ... Absorber, 8,9 ... Solution heat exchanger, 18 ... Cooling water pipe, 20 ... Cold / hot water pipe, 30 ... Vacuum Degree diagnostic device, 32 ... Temperature detector, 33 ... Judgment reference value calculator, 34 ... Present value calculator, 35 ... Comparison calculator, 36 ... Weight calculator, 37 ... Weight value aggregate value comparison Calculator, 38 …… Display.

Front Page Continuation (72) Inventor Kahei Arita 1370 Koyasu-cho, Hamamatsu City, Shizuoka Prefecture Yazaki General Stock Company In-house (56) References JP 64-28454 (JP, A) JP 64-38574 (JP, A)

Claims (2)

[Claims] 1. An evaporator for evaporating a liquid refrigerant supplied from a condenser and exchanging heat with cold / hot water flowing in a cold / hot water pipe, and a cooling water flowing through a refrigerant vapor evaporated in the evaporator. An absorber for contacting and absorbing the absorbing liquid on the surface of the cooling water pipe is provided, and a dilute solution obtained by absorbing the refrigerant vapor flowing out from the absorber is heated to separate the refrigerant vapor and the absorbing liquid.
In the vacuum degree diagnostic device for determining the quality of the vacuum degree of the absorption chiller-heater configured to be circulated and supplied to the condenser and the absorber, respectively, the outlet temperature Tb of the hot and cold water, the liquid refrigerant in the evaporator Evaporation temperature Te, outlet temperature Td of the absorbing liquid flowing out of the absorber, temperature detectors for detecting the inlet temperature Ta and the outlet temperature Tc of the cooling water, and the evaporation temperature T
e, the difference Tda between the absorption liquid outlet temperature Td and the cooling water inlet temperature Ta, and the difference Tdc between the absorption liquid outlet temperature Td and the cooling water outlet temperature Tc, respectively, are used as the judgment factors, and the detected cold / hot water outlet temperature Tb and the cooling water inlet Judgment reference value calculation means for obtaining the judgment reference value of each of the judgment elements in a predetermined normal operating state based on the temperature Ta, and the present value of the judgment element based on the detected temperature of each part, A vacuum degree diagnosing device for an absorption chiller-heater, comprising: a vacuum degree judging means for comparing the present value with the judgment reference value to judge whether the vacuum degree is good or bad. 2. The vacuum degree diagnostic device according to claim 1, wherein said vacuum degree determining means makes a determination by adding a predetermined weight to each comparison result of said determination elements.