JPH09257343A - Absorption refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the operation cost in a cooling operation by stopping an absorption refrigerating machine when either temperature or pressure of a high temperature regenerator or temperature of an evaporator or outlet temperature of cold water exceeds a preset reference value to start a bleeding action. SOLUTION: This absorption refrigerating machine includes a noncondensing gas bleeding device for extracting noncondensing gas from an evaporator 34 or absorber 44 by means of an ejector 57 in which absorption solution pressurized by a solution circulation pump 54 is used as driving fluid. During the cooling operation of the absorption refrigerating machine, a controller 13 compares, at a specified time intervals, a preset reference value with each output of an evaporator temperature sensor 65, evaporator pressure sensor 66, high temperature regenerator temperature sensor 67, high temperature regenerator pressure sensor 68, cold water outlet temperature sensor. When any one of the outputs exceeds the reference value, it is judged that amount of noncondensing gas in the system has exceeded art allowable value, and combustion of a high temperature regenerator 10 is stopped and a solenoid valve 55 is opened to start a bleeding acion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerating machine, and more particularly to an absorption refrigerating machine having a non-condensable gas extraction device.

[0002]

2. Description of the Related Art In an absorption refrigeration machine, non-condensable gas is generated at the stage of material corrosion and film formation due to an absorption solution heated to a high temperature, or non-condensable gas leaks into the system from the outside. Sometimes The amount of non-condensable gas generated during the material corrosion or film formation step is generally about 0.1 to 0.2 cc / (hr · RT). The presence of such non-condensable gas causes the degree of vacuum inside the machine to fall below the planned value (the pressure increases). Since the reduction of the in-machine vacuum degree from the planned value is a cause of reducing the cooling capacity, it is necessary to extract the non-condensable gas outside the machine and maintain the vacuum degree at a predetermined value.

As means for extracting the non-condensable gas, an auxiliary absorber connected to the absorber, a gas separator connected to the auxiliary absorber, and an ejector connected to the gas separator on the suction side are provided. Used to send the non-condensable gas separated by the gas separator to the gas storage chamber by the ejector, or the mixed fluid of the refrigerant vapor and the non-condensable gas is sucked into the separator by the ejector directly from the absorber. There is one in which a non-condensable gas is separated from a mixed fluid and sent to a gas storage chamber. In either case, it is common to drive the ejector by using a part of the dilute solution pressurized by the solution circulation pump as a driving fluid, and as an example using a combination of auxiliary absorber-gas separator-ejector, There is one disclosed in JP-A-2-247465, and examples of using a combination of an ejector-gas separator include those disclosed in JP-A-7-19670 and JP-A-2-17369. is there. FIG. 4 shows an example of a system configuration of an absorption refrigerator when an ejector-gas separator combination is used.

[0004]

In such a conventional bleeding apparatus, since the non-condensable gas that is generated is bleeding during the cooling operation, in addition to the dilute solution sent to the high temperature regenerator during the bleeding operation, the ejector drive is performed. A dilute solution for use was required, and a solution circulation pump was required to obtain a discharge amount larger than the circulation amount of the absorption solution required for the refrigeration cycle. Therefore, the pump becomes large and the motor power also becomes large, making it difficult to downsize the device and save power.

An object of the present invention is to reduce the size and power consumption of an absorption refrigerating machine equipped with a non-condensable gas extraction device using an ejector driven by a dilute solution pressurized by a solution circulation pump.

[0006]

In order to solve the above problems, the present invention solves the above problems by using a high temperature regenerator 10, a separator 16 and a condenser 2.
6, an evaporator 34, an absorber 44, and a solution circulation pump 54 are connected by piping to form an absorption refrigeration cycle, and a non-condensable property is obtained by using an ejector 57 that uses the absorption solution pressurized by the solution circulation pump 54 as a driving fluid. In an absorption refrigerator having a non-condensable gas extraction device that extracts gas from the evaporator 34 or the absorber 44, a temperature sensor that detects the temperature of the high temperature regenerator 10 and a pressure that detects the pressure of the high temperature regenerator 10. At least one of a sensor, a temperature sensor that detects the temperature of the evaporator 34, a pressure sensor that detects the pressure of the evaporator 34, and a temperature sensor that detects the temperature of cold / hot water at the outlet of the evaporator, and the solution circulation. A branch pipe 64 that connects the discharge side pipe 63 of the pump 54 and the drive fluid inlet of the ejector 57 via an electromagnetic valve 55, and the temperature sensor or a pressure sensor that detects pressure. Control means for determining whether or not the amount of the non-condensable gas in the high temperature regenerator 10 or the evaporator 34 has exceeded a preset limit value by using the output as an input, and the control means is configured to perform the high temperature regeneration. When it is determined that the amount of the non-condensable gas in the evaporator 10 or the evaporator 34 exceeds a preset limit value, the absorption refrigerating machine is temporarily stopped and the equipment is controlled to execute the extraction operation. Characterize.

As described above, in the absorption refrigerator, the non-condensable gas is generated in the stage where the absorption solution heated to a high temperature corrodes the material or the film is formed, and the non-condensable gas is externally introduced into the system. However, the amount of non-condensable gas generated during the material corrosion or film formation step is generally 0.1 to 0.2 cc / (h
r · RT). When non-condensable gas is generated in the machine, the pressure of the high temperature regenerator and the evaporator rises. When the pressures of the high temperature regenerator and the evaporator increase, the temperatures of the high temperature regenerator and the evaporator and the evaporator outlet temperature of cold / hot water also increase accordingly. When the temperature (pressure) of the high-temperature regenerator or evaporator or the evaporator outlet temperature of cold / hot water rises above the preset reference value, the control means detects it and detects the non-condensable gas. When it is determined that the amount exceeds the limit value, the absorption refrigerator is temporarily stopped and the device is controlled to execute the extraction operation. The suspension of the absorption refrigerator here means
It means the stop of heat input (heating of dilute solution) due to combustion etc. in the high temperature regenerator, the solution circulation pump continues to operate, and the cooling water and load side refrigerant (heat medium) also continue to circulate. . The bleeding operation is performed by temporarily stopping the absorption refrigerating machine, then by presetting a time, by opening the solenoid valve interposed in the branch pipe, and after the set time has elapsed, the solenoid valve is closed, The operation of the absorption refrigerator is restarted. Since the dilution operation is not performed during the extraction operation, the refrigeration cycle can be set up smoothly even when the operation of the absorption refrigerator is restarted.

Under what conditions, it is determined by the specifications and operating conditions of each absorption refrigerator that the high temperature regenerator 10 or the evaporator 34 is judged to have exceeded the preset limit value. You should do it. For example, set as follows.

The pressure of the high temperature regenerator, the temperature of the high temperature regenerator,
When any one or more of the evaporator pressure, evaporator temperature, and cold / hot water evaporator outlet temperature exceeds the reference value. Either of the evaporator temperature or cold / hot water evaporator outlet temperature. If the temperature exceeds the reference value continuously for 1 to 2 hours, all of the high temperature regenerator pressure, high temperature regenerator temperature, evaporator pressure, evaporator temperature, and evaporator outlet temperature of cold / hot water are Instead of measuring, one of them may be measured and the judgment may be made according to the measurement.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a main configuration of an absorption refrigerator according to an embodiment of the present invention. The illustrated absorption refrigerating machine uses, as a working fluid, an absorbing solution in which lithium bromide (LiBr) which is an absorbent absorbs water which is a refrigerant. The LiBr concentration of the absorbing solution fluctuates as the working fluid circulates through the apparatus, and this fluctuation can be divided into approximately three stages. From the lower concentration level, they are called a dilute solution, an intermediate concentrated solution, and a concentrated solution. .

The absorption refrigerator shown in the figure includes a high temperature regenerator 10 having means for heating an absorption solution (dilute solution) contained therein,
Low-temperature regeneration in which a separator 16 arranged above the high-temperature regenerator 10 and connected to the high-temperature regenerator 10 by an ascending pipe 14 and a refrigerant vapor coil 23 having one end connected to a gas phase portion of the separator 16 are installed. And a low-temperature regenerator 22 connected to the low-temperature regenerator 22 by a secondary refrigerant vapor passage 28, the other end of the refrigerant vapor coil 23 is connected, and a condenser 2 having a cooling water coil 50 installed therein.
6, an evaporator 34 which is connected to the condenser 26 by a liquid refrigerant pipe 30 and has an evaporation coil 32 installed therein, and an absorber 44 which is in communication with the evaporator 34 through an evaporation refrigerant vapor passage and has a cooling water coil 46 installed therein, A solution circulation pump 54 whose suction side is connected to the bottom of the absorber 44 by a dilute solution suction pipe 52, and a diluted solution discharge pipe 63 whose heated fluid inlet side is on the discharge side of the solution circulation pump 54.
And a low temperature solution heat exchanger 42 connected to each other through a heated fluid outlet side of the low temperature solution heat exchanger 42 and a heated fluid outlet side thereof connected to the heated fluid outlet side of the high temperature regenerator 10. The high temperature solution heat exchanger 36 connected to the above, the intermediate concentrated solution pipe 20 connecting the liquid phase part of the separator 16 and the heating fluid inlet of the high temperature solution heat exchanger 36, and the high temperature solution heat exchanger 3
6, an intermediate concentrated solution pipe 38 for connecting the heating fluid outlet side of 6 to the low temperature regenerator 22, a concentrated solution pipe 40 for connecting a bottom portion of the low temperature regenerator 22 and a heating fluid inlet side of the low temperature solution heat exchanger 42, and a low temperature solution Containing a concentrated solution pipe 41 connecting the heating fluid outlet side of the heat exchanger 42 and the upper part of the absorber 44, and a cooling water pipe 48 connecting the outlet side of the cooling water coil 46 and the inlet side of the cooling water coil 50. It is configured.

In the illustrated absorption refrigerator, the absorber 44 is also used.
Is connected to the extraction pipe 56, and an ejector 57 having a suction side connected to the extraction pipe 56 is arranged.
A branch pipe 64 with a solenoid valve 55 interposed in the dilute solution discharge pipe 63.
And the branch pipe 64 is connected to the drive fluid inlet of the ejector 57. The discharge side of the ejector 57 is connected to the gas separator 59 via the ejector discharge pipe 58. The bottom of the gas separator 59 is connected to the bottom of the absorber 44 via a solution return pipe 60, and the top of the gas separator 59 is connected to a gas tank 62 via a gas rising pipe 61. Although the extraction pipe 56 is connected to the absorber 44 in this embodiment, it may be connected to the evaporator 34.

Further, the evaporator temperature sensor 65 and the evaporator pressure sensor 66 which detect and output the temperature and pressure of the evaporator 34 respectively, and the high temperature regenerator which detects and output the temperature and pressure of the high temperature regenerator 10, respectively. A temperature sensor 67, a high temperature regenerator pressure sensor 68, and a cold / hot water outlet temperature sensor 69 (not shown) that detects and outputs the evaporator outlet temperature of cold / hot water are provided. A controller 13 to which the outputs of these temperature sensor and pressure sensor are input is provided, and the controller 13 controls the combustion of the high temperature regenerator 10 and the opening / closing of the solenoid valve 55.
According to the temperature sensors 65, 67, 69 and the pressure sensor 6
It is controlled based on the outputs of 6,68. In the illustrated example, the pressure of the high temperature regenerator 10 is measured by the pressure sensor 68 provided in the separator 16.

The extraction operation of the absorption refrigerator having the above structure will be described below with reference to FIG. The controller 13, which is the control means, confirms whether the absorption refrigerator is in the cooling operation or the dilution operation, and during the cooling operation, the temperature sensors 65, 67, 69, and the pressure sensor 66, at predetermined time intervals. The outputs of 68 are compared with preset reference values for each. When it is detected that one of the outputs exceeds the preset reference value, the controller 13 starts the extraction operation. In the figure, the high temperature regenerator temperature sensor 67
However, the outputs of other sensors may be compared, or some of the sensors may be combined and compared sequentially. Further, in this embodiment, the temperature sensors 65, 67, 6
9. Although the pressure sensors 66 and 68 are provided, it is not necessary to provide all of these sensors for controlling the extraction operation. Any one or more of these may be provided.

As a result of the comparison, when it is detected that the output of one of the sensors exceeds a preset reference value,
The controller 13 determines that the amount of the non-condensable gas in the system exceeds the allowable value, and stops the combustion of the high temperature regenerator 10 (the heat input when the heat is input by a method other than combustion),
The solenoid valve 55 is opened. The solution circulation pump 54 continues to operate, and a part of the diluted solution pressurized by the solution circulation pump 54 is guided to the drive fluid inlet of the ejector 57 via the electromagnetic valve 55 to drive the ejector 55.

The refrigerant vapor containing the non-condensable gas in the absorber 44 is sucked by the ejector 57, mixed with the dilute solution as the driving fluid, and sent to the gas separator 59.
The mixed fluid sent to the gas separator 59 is separated into a dilute solution and a non-condensable gas, and the separated non-condensable gas is sent to a gas tank 62 via a gas rising pipe 61 and stored therein. The dilute solution separated by the gas separator 59 is returned to the bottom of the absorber 44 via the solution return pipe 60.

Although an example of the amount of non-condensable gas generated during normal operation has been described above, in general, the extraction system produces about 3 times the amount of non-condensable gas generated when the equipment is operated for 10 hours. Plan to bleed in ~ 7 minutes. That is, the combustion stop time of the high temperature regenerator 10 and the open time duration of the solenoid valve 55 are set to about 3 to 7 minutes. When the set time has elapsed, the solenoid valve 55 is closed again and the ejector 57 is closed.
Is stopped, the combustion of the high temperature regenerator 10 is started, and the cooling operation is restarted. Since the dilution operation is not performed even if the absorption refrigerator is temporarily stopped due to the extraction operation, the refrigeration cycle smoothly starts even when the refrigeration operation is restarted.

In the above explanation, the extraction operation is started when the output of the sensor exceeds the set reference value. However, the evaporator temperature (output of the evaporator temperature sensor) or the cold / hot water temperature (cold / hot water outlet temperature) When starting the bleeding operation based on the output of the sensor), it is desirable to start the bleeding operation after the state where the sensor output exceeds the reference value continues for 1 to 2 hours. Since the evaporator temperature and cold / hot water temperature are easily affected by load fluctuations, if the bleeding operation is performed immediately each time the sensor output exceeds the reference value, useless bleeding operation is actually performed even if there is no non-condensable gas. It is easy to increase the number of cases.

Further, in the flow chart of FIG. 2, the bleeding operation is performed only during the cooling operation, but at the same time, during the dilution operation after the cooling operation is completed (or after the dilution operation is completed), It is desirable to open the solenoid valve 55 and perform bleeding for a preset time regardless of the output value of each temperature sensor and pressure sensor. In this way, at the stage where the non-condensable gas has not reached the amount to start the extraction operation, the non-condensable gas is removed without affecting the cooling load, and the non-condensable gas will be supplied during the next cooling operation. You can start the refrigeration cycle in the absence of. FIG. 3 is a flowchart showing the procedure for performing the extraction operation during the dilution operation after the cooling operation is completed. When the bleeding operation is performed during the diluting operation, for example, a timer that starts at the start of the diluting operation may be provided and the bleeding operation may be started after a predetermined time has elapsed.
However, if the bleeding operation is also completed at the end of the dilution operation, it is not necessary to extend the operating time of the pump for bleeding.

The required discharge amount of the solution circulation pump 54 during the dilution operation is smaller than that during the refrigeration cycle operation, and even if the extraction operation is performed during the dilution operation, it is not necessary to increase the capacity of the solution circulation pump.

[0021]

According to the present invention, any one of the temperature or pressure of the high temperature regenerator, the temperature or pressure of the evaporator, and the hot / cold water outlet temperature is monitored during the cooling operation, and any one of them is set as a preset standard. If this value is exceeded, the absorption chiller will be stopped and the extraction operation will be performed even during the cooling operation, and the non-condensable gas will be removed from the absorber or evaporator. Is avoided, and fuel costs, that is, operating costs are reduced. Moreover, since it is not necessary to add the amount of solution for driving the ejector for extraction to the amount of the dilute solution discharged from the solution circulation pump during the operation of the refrigeration cycle, the solution circulation pump is It is only necessary to maintain the necessary circulating amount of the dilute solution, the capacity can be reduced, the device can be downsized, and the power cost can be reduced.

[Brief description of drawings]

FIG. 1 is a system diagram showing a main part configuration of an absorption refrigerator according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an example of a procedure of an extraction operation of the present invention.

FIG. 3 is a flowchart showing another example of the procedure of the extraction operation of the present invention.

FIG. 4 is a system diagram showing a main configuration of an example of a conventional technique.

[Explanation of symbols]

10 High Temperature Regenerator 13 Controller 14 Ascending Pipe 16 Separator 20 Intermediate Concentrated Solution Pipe 22 Low Temperature Regenerator 23 Refrigerant Vapor Coil 26 Condenser 28 Secondary Refrigerant Vapor Passage 30 Liquid Refrigerant Pipe 32 Evaporation Coil 34 Evaporator 36 High Temperature Solution Heat Exchanger 38 Intermediate concentrated solution pipe 40 Concentrated solution pipe 41 Concentrated solution pipe 42 Low temperature solution heat exchanger 44 Absorber 46 Cooling water coil 48 Cooling water pipe 50 Cooling water coil 52 Dilute solution suction pipe 54 Solution circulation pump 55 Solenoid valve 56 Extraction pipe 57 Ejector 58 Ejector discharge pipe 59 Gas separator 60 Solution return pipe 61 Gas rising pipe 62 Gas tank 63 Dilute solution discharge pipe 64 Branch pipe 65 Evaporator temperature sensor 66 Evaporator pressure sensor 67 High temperature regenerator temperature sensor 68 High temperature regenerator pressure sensor 69 Cold temperature Water outlet temperature sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Tonmiya 1370 Koyasu-cho, Hamamatsu-shi, Shizuoka Yazaki General Stock Company In-house

Claims (5)

[Claims] 1. A high temperature regenerator, a separator, a condenser, an evaporator,
An absorption refrigeration cycle is configured by connecting an absorber and a solution circulation pump to a pipe, and the non-condensable gas is extracted from the evaporator or absorber using an ejector that uses the absorption solution pressurized by the solution circulation pump as a driving fluid. In an absorption refrigerator comprising a non-condensable gas extraction device, a temperature sensor for detecting the temperature of the high temperature regenerator, a pressure sensor for detecting the pressure of the high temperature regenerator, a temperature sensor for detecting the temperature of the evaporator, and an evaporator. One or more of a pressure sensor for detecting the pressure of the pressure sensor and a temperature sensor for detecting the temperature of cold / hot water at the outlet of the evaporator, a discharge side pipe of the solution circulation pump and a driving fluid inlet of the ejector are connected to a solenoid valve. The amount of the non-condensable gas in the high temperature regenerator or the evaporator is preset with the output of the temperature sensor or the pressure sensor for detecting the pressure as an input. Control means for determining whether the limit value is exceeded, comprising the control means, when it is determined that the amount of the non-condensable gas in the high temperature regenerator or the evaporator exceeds a preset limit value, An absorption refrigerating machine, which controls the equipment so as to temporarily stop the absorption refrigerating machine and execute an extraction operation. 2. The control for temporarily stopping the absorption refrigerator and executing the extraction operation includes stopping heating of the absorption solution in the high temperature regenerator,
The absorption refrigerator according to claim 1, further comprising an opening operation of a solenoid valve. 3. The absorption refrigerating machine according to claim 1, wherein the control means also has a function of executing an extraction operation during the dilution operation of the absorption refrigerating machine. 4. The absorption refrigerating machine according to claim 3, wherein the control means starts the extraction operation after a lapse of a predetermined time after starting the dilution operation of the absorption refrigerating machine. 5. An absorption refrigeration cycle is constituted by connecting a high temperature regenerator, a separator, a condenser, an evaporator, an absorber and a solution circulation pump to a pipe, and the absorption solution pressurized by the solution circulation pump is used as a driving fluid. In a non-condensable gas extraction method for an absorption refrigerator, which comprises an ejector for extracting non-condensable gas from an evaporator or an absorber using an ejector, the temperature of the high temperature regenerator and the high temperature regenerator One or more of the pressure, evaporator temperature, evaporator pressure, and evaporator outlet temperature of cold / hot water are detected, and any one or more of the detected values are set in advance corresponding to each. A non-condensable gas extraction method for an absorption refrigerating machine, characterized in that heat input to the high-temperature regenerator is stopped and the ejector is driven to perform an extraction operation when the specified reference value is exceeded.