JPH0233584A - Vacuum degree diagnosing device for absorption type water cooling and heating machine - Google Patents

Abstract

PURPOSE:To diagnose a vacuum degree from only the temperatures of the constituting elements of an absorption type water cooling and heating machine and a piping system connecting respective elements by a method wherein the present values of judging elements and the judging reference values of the same are obtained based on the temperatures of respective units, which are detected by temperature detectors, and the present values are compared with the judging reference values. CONSTITUTION:A vacuum degree diagnosing device 30 is formed of a main body 31, formed movably, and temperature detectors 31a-32e, detecting the temperatures of respective units of an absorption type water cooling and heating machine. The main body 31 is formed of a judging reference value operator 33, a present value operator 34, a comparing operator 35, a weight operator 36, a total amount of weight comparing operator 37 and an indicating unit 38. A vacuum degree judging means is formed of the comparing operator 35, the weight operator 36 and the total amount of weight comparing operator 37. There exist strong correlations between the evaporating temperature and the vacuum degree of liquid refrigerant, between a temperature difference of the outlet temperature of absorbing solution and the inlet temperature of cooling water and the vacuum degree and between a temperature difference of the absorbing solution outlet temperature and the cooling water outlet temperature and the vacuum degree while the diagnosis of the vacuum degree may be effected by employing these three factors as elements for judgement.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a diagnostic device for the operating state of an absorption chiller/heater, and specifically, it is a device for diagnosing the operating status of an absorption chiller/heater, and specifically, it is a device for diagnosing the operating status of an absorption chiller/heater. The present invention relates to a vacuum degree diagnostic device for an absorption chiller/heater that diagnoses by

[Conventional technology]

In general, an absorption chiller/heater includes an evaporator that evaporates liquid refrigerant supplied from a condenser and exchanges heat with cold/hot water flowing through cold/hot water pipes, and an evaporator that converts the evaporated refrigerant vapor in the evaporator into cooling water. The absorber is configured to include an absorber that contacts and absorbs the absorption liquid on the surface of the cooling water pipe through which it flows. Then, a dilute solution obtained by absorbing refrigerant vapor flowing out from the absorber is heated and separated into refrigerant vapor and absorption liquid, which are each circulated and supplied to the condenser and the absorber.

In order to operate the absorption chiller/heater configured in this manner with high efficiency, it is necessary to appropriately diagnose the degree of vacuum within the absorption chiller/heater to maintain a high degree of vacuum.

Conventionally, as a method for diagnosing the degree of vacuum, a pressure detector (compound gauge, manometer, pressure sensor, etc.) is attached to the evaporator or absorber via a pressure detection valve, and after the inside of the connecting pipe is evacuated, It is known to open a pressure detection valve to determine the internal pressure of a water cooler/heater, and then make a judgment based on the value shown by the detector.

Another method is to measure the refrigerant liquid temperature in the evaporator.
The saturated vapor pressure of the refrigerant was determined from that temperature by calculation (or diagram), the absorber outlet temperature of the absorption liquid, and the liquid was sampled (taken from the liquid sampling valve using a vacuum pump). The degree of vacuum was diagnosed by measuring the concentration and comparing it with the saturated vapor pressure of the solution calculated from the concentration and temperature (or a diagram of the solution).

[Problem to be solved by the invention]

However, the conventional known technology has the following first-order problems.

(1) The work requires skill.

(2) Requires equipment such as highly accurate and expensive measuring equipment and vacuum pumps. In addition, it is difficult to transport these devices to and from the site.

(3) The valves of the refrigerator (pressure test, liquid sampling) are opened and closed during work, so there is a risk of vacuum breakdown.

(4) In general, the solution used in absorption water coolers and heaters is highly corrosive, so it may damage the equipment or cause corrosion due to the solution scattering during work.
This may lead to rust.

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

The problem of the present invention is to diagnose the vacuum state of an absorption chiller/heater.
It is an object of the present invention to provide a degree of vacuum diagnosis device that can accurately diagnose the degree of vacuum based only on temperature information of the constituent elements of a water cooler and a pipe system connecting each element, without using a pressure gauge or a concentration meter.

[Means to solve the problem]

In order to solve the above problems, the present invention aims at
b, evaporation temperature Te of the liquid refrigerant in the evaporator, and outlet temperature Td of the absorption liquid flowing out from the absorber.

Temperature detectors each detect the inlet temperature Ta and outlet temperature Tc of the cooling water; Judgment reference value calculation means for determining a judgment reference value of each judgment element in a predetermined normal operating state based on the detected cold/hot water outlet temperature Tb and cooling water inlet temperature Ta, using the difference TdC as a judgment element. , vacuum degree determining means for determining the current value of the determination element based on the detected temperature of each part, and comparing the current value with the determination reference value to determine whether the degree of vacuum is good or bad. The reason is that it has become a degree diagnostic device.

[Effect]

Between the evaporation temperature Te of the liquid refrigerant of the absorption chiller/heater and the degree of vacuum,
Also, between the temperature difference Tda between the absorption liquid outlet temperature Td and the cooling water inlet temperature Ta and the degree of vacuum, and between the temperature difference 'I-dc between the absorption liquid outlet temperature Td and the cooling water outlet temperature Tc and the degree of vacuum, , each has a strong correlation. Therefore, the present invention diagnoses the degree of vacuum using these three items as determining factors.

Further, the criterion value for determining whether the degree of vacuum is good or bad based on the above-mentioned determining factors is related to the operating state (load state) of the absorption chiller/heater. In addition, the operating status is the cold/hot water outlet temperature T
Since b is correlated with the cooling water inlet temperature Ta, the value of the above-mentioned judgment element in the operating state at a normal degree of vacuum is determined based on these detected temperatures, and this is used as the judgment reference value.

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

This judgment is made for each of the above three judgment factors.

Comprehensive judgment will be made based on their quality.

In this case, since the degree of influence on the quality/failure determination of the degree of vacuum differs depending on the determination element, it is desirable to weight the comparison results of each determination element and make the determination.

〔Example〕

Hereinafter, the present invention will be explained based on examples. FIG. 1 shows a schematic diagram of the configuration of a vacuum degree diagnosing device 30 according to an embodiment of the present invention. The vacuum degree diagnostic device 30 of this embodiment includes a movable main body 31 and temperature detectors 32a to 32e that detect the temperature of each part of the absorption chiller/heater. The main body 31 includes a judgment reference value calculator 33, a current value calculator 34, and a comparison calculator 35.
, a weight calculation unit 36 , and a weight total value comparison calculation unit 37 .

It is formed to include a display 38. The comparison calculator 35, the weight calculator 36, and the weighted total value comparison calculator 37 form vacuum degree determining means. In addition, the temperature detector 32
a to 32e are connectors 39a to 39 provided on the main body 31
e respectively with flexible wires, and each connector 39a to 39
e is connected to the judgment reference value calculator 33 and the current value calculator 34 as appropriate.

The detailed configuration of each of the arithmetic units described above will be explained below along with the operation thereof. The explanation will be given by taking an absorption chiller/heater shown in FIG. 2 as an example of the diagnosis target.

First, the absorption chiller/heater shown in FIG. 2 will be explained. A dilute solution formed by absorbing the refrigerant is heated in a regenerator 1 and led to a separator 2, where it is separated into refrigerant vapor and absorption liquid. This absorption liquid is a medium-concentrated solution containing unevaporated refrigerant, and is led to the low-temperature regenerator 3 via the first heat exchanger 9, where the refrigerant is further evaporated and separated. The concentrated solution leaving 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 in the separator 2 is transferred to the low temperature regenerator 3.
The cooling water is led to the condenser 4 via the cooling water pipe 1.
Heat is taken away by the cooling water flowing through 8 and condensed. The condensed liquid refrigerant is led to the top of the evaporator 5,
The water flows down onto the surface of a hot and cold water pipe 20 disposed 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 through the cold/hot water pipe 20.

The refrigerant vapor vaporized in the evaporator 5 is guided to the absorber 6,
It comes into contact with the absorption liquid (concentrated solution) flowing down onto the surface of the cooling water pipe 18 disposed in the absorber 6 and is absorbed. The absorbed heat generated at this time is removed by cooling water. Absorber 6
The dilute solution that has absorbed the refrigerant 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 interior 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.

(2) The evaporation temperature Te of the evaporator 5 increases as the degree of vacuum decreases.

(In a water cooler/hot water machine that does not have a refrigerant pump that returns unevaporated liquid refrigerant flowing down to the bottom of the evaporator 5 to the top, when the amount of refrigerant evaporated in the evaporator 5 decreases, the unevaporated liquid refrigerant This liquid refrigerant flows into the absorber 6 and is directly mixed with the absorption liquid to generate dilution heat.Since this heat is not in contact with the cooling water pipe 18, there is no chance of it being discarded into the cooling water, and the rare case where it is emitted from the absorber 6. Increase the temperature of the solution.Therefore, the temperature difference Tda between the absorber outlet temperature Td of the dilute solution and the cooling water inlet temperature Ta
(=Td-Ta) increases as the degree of vacuum decreases.

■For the same reason as ■ above, and due to the decrease in the refrigerating capacity due to the decrease in vacuum degree, the amount of heat removed to the cooling water decreases, and due to the synergistic effect with the decrease in the cooling water outlet temperature Tc, the absorber outlet temperature Td of the dilute solution decreases. Temperature difference Tdc (
=Td-Tc) increases as the degree of vacuum decreases. Therefore, the degree of vacuum can be diagnosed using this three-terminal port as a determining factor.

Among the temperatures of each part necessary for the above judgment, the cooling water population temperature T
a is detected by the temperature detector 32a, cold and hot water outlet temperature Tb is detected by the temperature detector 32b, cooling water outlet temperature Tc is detected by the temperature detector 32c, and absorption liquid outlet 11 temperature Td is detected by the temperature detector 3.
2d, the evaporation temperature Tc is detected by the temperature detector 32e. These detectors 32
a = d is formed so that it can be attached to a pipe or the like to measure the corresponding temperature.

Among 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 judgment criteria 1 (ji values) corresponding to the judgment factors shown in Table 1 are determined.

From the first expression, it is determined based on 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 breakdown.

On the other hand, based on the detected and input cooling water inlet temperature Ta, cooling water outlet temperature Tc, dilute solution absorber outlet temperature Td, and evaporator temperature Te, the current value calculator 34 calculates the judgment factors shown in Table 2. The current temperature difference (current value) for each time is calculated.

Table 2 These judgment reference values J1 to J3 are the values of judgment factors that are considered to be the same under normal vacuum conditions, and the values also vary depending on the load condition etc. As shown in the flowchart in Figure 3. is input to the comparison calculator 35, which compares the judgment reference value and the current value for each judgment element, and determines whether the degree of vacuum in the judgment element is good or bad. If the current value is smaller than the judgment reference value, it is judged to be good (EGV), and if it is larger than the judgment reference value, it is judged to be bad (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.
E corresponding to the comparison result of the comparison calculator 35
Weight value W1. is assigned to either GV or ELV judgment frame. W2
．． W, are set respectively. This weight value represents the degree of influence of each judgment element on the degree of vacuum judgment.
It is set and stored in advance so that the total is 1 or 100%. The weight summary value comparison calculator 37 is the weight calculator 3
6, the content is divided into good (EGV) or bad (ELV) and the values are totaled. The EGV total value is compared with the ELV total value, and if the ELV total value is large, it is determined that the degree of vacuum is poor, and the determination signal is output to the display 38. For example, a judgment signal indicating that the degree of vacuum is good is output to the display 38. Note that the display 38 may display the calculated total values of EGL and ELV. In addition to the liquid crystal display, the display 38 also has a liquid crystal display.
A lamp display can also be applied.

Note that when a diagnosis of poor vacuum is made, the signal can be used to operate the oil/air system. Also, for water coolers and hot water machines that have a refrigerant pump.

Even if the amount of refrigerant evaporated in the evaporator 5 decreases, the dilute solution and the refrigerant liquid do not mix, and the amount of heat absorbed in the absorber 6 simply decreases. Therefore, contrary to the above phenomenon, the absorber outlet temperature Td of the dilute solution decreases. As described above, the dilute solution absorber outlet temperature Td exhibits opposite phenomena depending on whether there is a refrigerant pump or not, so the diagnosis can be made in the same manner as in the above embodiment by reversing the judgment. In other words, the judgment factor Tda
The inequality sign of the determination of Tdc and Tdc may be reversed.

Furthermore, in the above embodiment, the degree of vacuum is determined using three determination elements, but it is also possible to determine the degree of vacuum using any one or a combination of two of the three determination elements. In that case, the accuracy and reliability of vacuum degree determination may decrease accordingly.

In addition, although the above embodiment has been described for a dual-effect absorption chiller/heater as a diagnostic target, it can also be applied to a single-effect absorption chiller/heater by replacing the calculation formula for calculating the one-judgment reference value.

As mentioned above, it is possible to tell whether the vacuum level of an absorption chiller/heater is good or bad without using a concentration meter or pressure gauge.
Diagnosis can be made by detecting the temperature, and there is no need to install any special equipment in the water cooler/heater in advance. In addition, the only work required for diagnosis is 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 can be shortened. Furthermore, since the diagnosis is performed by combining a plurality of judgment factors, the accuracy of the diagnosis is high.

〔Effect of the invention〕

According to the present invention, a temperature detector, a judgment reference value calculating means for calculating a judgment reference value based on the detected temperature, a current value calculating means for calculating a current value based on the detected temperature, and a calculating means for calculating a current value based on the detected temperature. The device is configured with a degree of vacuum determination means that determines the degree of vacuum based on the determined reference value and the current value, and the degree of vacuum is diagnosed only from the temperature of the components of the absorption chiller/heater and the pipe system connecting each element. This has the effect of making it possible to diagnose accurately without using a pressure gauge or concentration meter.

[Brief explanation of the drawing]

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 the embodiment of Fig. 1 is attached to an absorption chiller/heater, and Fig. 3 is an implementation of the embodiment shown in Fig. 1. FIG. 4 is a flowchart showing the procedure of vacuum degree diagnosis in an example. FIG. 4 is a diagram showing changes in each determination element when a vacuum degree defect 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, 2o...Cold/hot water pipe, 30...Vacuum degree diagnostic device, 32...Temperature detector. 33... Judgment reference value calculator, 34... Current value calculator, 35... Comparison calculator, 36... Weight calculator, 37
...Weight value summary value comparison calculator, 38... Display device. Figure 1

Claims (1)

[Claims] 1. An evaporator that evaporates liquid refrigerant supplied from a condenser and exchanges heat with cold and hot water flowing through a cold and hot water pipe; It is equipped with an absorber that contacts and absorbs the absorption liquid on the surface of the cooling water pipe that flows through it, and the dilute solution formed by absorbing the refrigerant vapor flowing out from the absorber is heated and separated into the refrigerant vapor and the absorption liquid. In a vacuum degree diagnostic device for determining the quality of the vacuum degree of an absorption chiller/heater that circulates and supplies the water to the condenser and the absorber, the outlet temperature T_b of the cold and hot water, the liquid in the evaporator The evaporation temperature T_e of the refrigerant, the outlet temperature T_d of the absorption liquid flowing out from the absorber, and the inlet temperature T_ of the cooling water.
a and an outlet temperature T_c;
The evaporation temperature T_e, the difference T_d_a between the absorption liquid outlet temperature T_d and the cooling water inlet temperature T_a, and the difference T_d_c between the absorption liquid outlet temperature T_d and the cooling water outlet temperature T_c are used as determination factors, respectively, and the detected cold/hot water outlet temperature T_b and the cooling Judgment reference value calculation means for calculating the judgment reference value of each judgment element in a predetermined normal operating state based on the water inlet temperature T_a; vacuum degree determining means for determining whether the degree of vacuum is good or bad by comparing the current value with the judgment reference value. 2. The vacuum degree diagnosing device according to claim 1, wherein said vacuum degree determining means makes a determination by adding predetermined weights to the comparison results of said respective determination elements.