JP4278237B2 - Absorption refrigerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption refrigerator (including an absorption chiller / heater and an absorption heat pump).
[0002]
[Prior art]
As is well known, an absorption refrigerator is connected to a regenerator, a condenser, an evaporator, an absorber, and the like in order, and water or the like is obtained by an absorbing solution composed of an aqueous solution of a halogen element salt (eg, lithium chloride, lithium bromide). When the refrigerant is circulated while being absorbed or released, it is a device that exchanges heat to provide a cooling action such as cooling or a heating action such as heating.
[0003]
In the absorption refrigerator having the above configuration, the regenerator, the condenser, the evaporator, the absorber, and the pipe portion connecting them are formed of iron or stainless steel, water as the refrigerant, lithium chloride or bromide as the absorption liquid. When a lithium aqueous solution or the like is used, the absorbing solution reacts with the metal of the device material to generate hydrogen gas when forming the anticorrosion film.
[0004]
In addition, the absorption chiller has a high vacuum as a whole in order to quickly evaporate the refrigerant. However, since it is a welded structure, intrusion of atmospheric components from pinholes and cracks is unavoidable. At the same time, atmospheric components such as nitrogen and oxygen increase.
[0005]
Hydrogen gas generated by the above mechanism and nitrogen and oxygen gas, which are atmospheric components that have entered the machine from the outside, do not condense at the cooling level in the refrigerator, and the solubility in the absorption liquid is extremely low. It stays in the non-solution part of the absorber and its concentration gradually increases. When the concentration of non-condensable gas such as hydrogen, nitrogen, oxygen, etc. in the machine increases in this way, the evaporation of the refrigerant is suppressed and the refrigeration capacity decreases.
[0006]
Therefore, a. Detecting the amount of bubbles discharged from a vacuum pump connected to the gas phase section of the apparatus, b. Although the pressure change in the machine is checked by a pressure sensor, the increase in non-condensable gas cannot be reliably captured by these methods.
[0007]
In addition, since it is impossible to determine whether the non-condensable gas increasing in the aircraft is hydrogen gas generated by the above mechanism or atmospheric components leaking from the outside, oxygen in the atmospheric components leaking from the outside can not be determined. There is an inconvenience that equipment components are exposed for a long period of time, and can take a variety of forms of corrosion, leading to serious accidents such as corrosion penetration.
[0008]
[Problems to be solved by the invention]
Therefore, it is necessary to be able to detect quickly and surely even a minute leak of atmospheric components, which has been a problem to be solved.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a gas leak sensor comprising two electrodes spaced apart and supported by a circuit in which refrigerant vapor circulates, and a thin wire stretched between the two electrodes. An absorption refrigerator that is installed so that the thin wire can come into contact with the refrigerant vapor flowing inside the refrigerant pipe, the refrigerant vapor circuit upstream of the gas leak sensor, and the refrigerant vapor circuit downstream of the gas leak sensor An absorption refrigerator having a first configuration in which an on-off valve is installed ;
[0014]
In the absorption refrigerating machine of the first configuration, a second configuration of the absorption refrigerator of gas leak sensor is adapted to couple the exhaust unit to the refrigerant vapor circuit disposed between each other off valve,
[0015]
In the absorption refrigerator of the first or second configuration, the absorption refrigerator of the third configuration in which the absorption liquid of the absorption refrigerator is an aqueous solution of a salt containing a halogen element system,
Is to provide.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the gas leak sensor 100 according to the present invention includes two electrodes 102A and 102B supported by an insulating material, for example, a mounting member 101 made of polyetheretherketone resin, and these electrodes. It is comprised from the thin wire | line 103 stretched so that a tensile stress may act between 102A, 102B.
[0017]
The thin wire 103 is formed by coiling a metal containing 1.5% or more of Ni, for example, austenitic stainless steel such as SUS-304, to a diameter of 500 μm, for example, into a coiled spring shape.
[0018]
The fine wire 103, which is an austenitic stainless steel and is supported by the electrodes 102A and 102B in a state where tensile stress is applied, causes intragranular stress corrosion cracking when exposed to an atmosphere in which oxygen and chloride coexist. .
[0019]
That is, a metal containing Ni, such as SUS304 (18-8 austenitic stainless steel), for example, as shown in FIG. 4, the higher the oxygen concentration, the higher the cracking sensitivity, and the conditions (metal composition, chloride concentration in the atmosphere, action) Depending on the magnitude of the tensile stress), cracking occurs even at an oxygen concentration of 1 ppm.
[0020]
In addition, the thin wire 103 that has undergone stress corrosion cracking is easily broken because it is pulled by the electrodes 102A and 102B. Whether or not the thin wire 103 is broken can be easily determined by applying a voltage and checking the conduction between the electrodes 102A and 102B.
[0021]
The gas leak sensor 100 having the above configuration is attached to the refrigerant pipe 14 between the on-off valves 26 and 27 of the absorption refrigerator shown in FIG. 2, for example, in the manner shown in FIG. That is, a mounting screw 101A is provided on the outer surface of the body portion of the attachment member 101, and the screw 101A is screwed into the screw 32A of the socket 32 attached to the refrigerant pipe 14, whereby the thin wire 103 of the gas leak sensor 100 is connected to the refrigerant. It is installed so as to be able to contact the refrigerant vapor flowing inside the pipe 14.
[0022]
In the absorption refrigerator shown in FIG. 2, 1 is a high temperature regenerator equipped with a gas burner 1B, 2 is a low temperature regenerator, 3 is a condenser, 4 is an evaporator, 5 is an absorber, 6 is a low temperature heat exchanger, 7 Is a high-temperature heat exchanger, 8 to 11 are absorption liquid pipes, 13 is an absorption liquid pump, 14 to 18 are refrigerant pipes, 19 is a refrigerant pump, and 21 is a cold / hot water that circulates and supplies a cold / heating load (not shown). A water pipe, 22 is a cold / hot water pump, 23 is a cooling water pipe, 24 and 25 are pressure equalizing pipes, and 26 to 31 are open / close valves. This absorption refrigerator has water as a refrigerant and a halogen element salt such as lithium chloride as an absorption liquid. This is a double-effect absorption refrigerator that circulates cold water or hot water to a load using an aqueous solution of In addition, since the structure which does not include the gas leak sensor 100 and the on-off valves 26 and 27 is conventionally known, the description of the operation of the absorption refrigerator itself is omitted.
[0023]
Then, the presence or absence of conduction between the electrodes 102A and 102B is checked regularly or periodically (for example, every hour), so that an increase in the outside air component in the machine is monitored with high accuracy.
[0024]
That is, the refrigerant vapor evaporated and separated from the absorption liquid by the high-temperature regenerator 1 and flowing through the refrigerant pipe 14 toward the low-temperature regenerator 2 includes a slight amount (for example, about 100 ppm) of lithium chloride as the absorption liquid. It is.
[0025]
When the concentration of lithium chloride is about this level and the oxygen concentration is less than 1 ppm, no stress corrosion cracking occurs in the thin wire 103, and when the oxygen concentration exceeds 1 ppm, stress corrosion cracking occurs in the thin wire 103. In the gas leak sensor 100 formed by determining the metal composition of the thin wire 103 so that the thin wire 103 breaks from the base point and applying a tensile stress of a required size to the thin wire 103, the gap between the electrodes 102A and 102B is determined. Only by monitoring the presence or absence of conduction, it is possible to detect even a slight amount of air leaking into the machine from the outside.
[0026]
The on-off valves 26 and 27 are installed on both sides of the gas leak sensor 100 so that the degree of vacuum in the machine does not decrease when the gas leak sensor 100 is attached or detached, and the fine wire 103 is not cracked when attached. .
[0027]
Further, a vacuum pipe 35 having a vacuum pump 33 and an open / close valve 34 indicated by a broken line is connected to the refrigerant pipe 14 between the open / close valves 26 and 27, and between the closed open / close valves 26 and 27. The air in the refrigerant pipe 14 is completely discharged by the vacuum pump 33 and the gas leak sensor 100 is attached. Even after the gas leak sensor 100 is attached, the air in the refrigerant pipe 14 between the on-off valves 26 and 27 is removed by the vacuum pump 33. If the on-off valves 26 and 27 are opened after that, it is possible to further prevent cracking when the thin wire 103 is attached and prevent the vacuum degree in the machine from being lowered.
[0028]
Further, as shown in FIG. 5, the gas leak sensor 100 is provided in the middle of the extraction pipe 38 extending from the absorber 5 to the ejector 37 of the extraction device 36, the extraction pipe 39 extending from the condenser 3, and the like. May be. Also in this case, although not shown, it is preferable to provide opening / closing valves on both sides of the gas leak sensor 100 and to connect a vacuum drawing pipe equipped with a vacuum pump between the opening / closing valves.
[0029]
Further, the thin wire 103 may be supported by the electrodes 102A and 102B in a curved bar spring shape after being cold drawn. When the thin wire 103 is curved, a compressive stress acts on a portion inside the center line, but a tensile stress acts on a portion outside the center line. Stress corrosion cracking occurs on the part side, and the crack progresses with this part as a base point and the thin wire 103 is broken, so that it can be used in the same manner as when it is formed in a coil spring shape.
[0030]
Further, the tensile stress applied to the thin wire 103 is applied by an appropriate member other than the electrodes 102A and 102B, and the electrodes 102A and 102B are connected to both ends of the thin wire 103 to which the tensile stress is applied. The electrode 102A, 102B, which applies a tensile stress to the thin wire 103 and applies a voltage thereto, is merely performed by two members, and this configuration is also included in the scope of the present invention. Is.
[0031]
The voltage applied to the electrodes 102A and 102B may be an AC voltage or a DC voltage. However, since the thin wire 103 to which the DC voltage is applied is less susceptible to stress corrosion, in this case, the voltage Is applied intermittently (for example, every hour) to check the continuity between the electrodes 102A and 102B.
[0032]
On the other hand, when an AC voltage is applied to the electrodes 102A and 102B, there is no inconvenience that stress corrosion is unlikely to occur at the thin wire 103. In this case, a voltage is always applied to check the continuity between the electrodes 102A and 102B. be able to.
[0033]
When the gas leak sensor 100 loses electrical continuity between the electrodes 102A and 102B, an alarm that air is leaking into the apparatus from the outside can be automatically output immediately.
[0034]
In addition, since the thin wire 103 may be cracked when exposed to the coexisting atmosphere of the absorption liquid vapor and atmospheric oxygen, its composition is appropriately selected in relation to the composition of the absorption liquid to be used. Is done. And in the austenitic stainless steel containing Ni, it can also comprise so that 0.4% or more of Cu and about 1-3% of Mo may be added in order to raise the sensitivity of the stress corrosion cracking.
[0035]
Further, since the thin wire 103 needs to be easily broken by the applied tensile stress when stress corrosion cracking occurs, its thickness is generally 500 μm or less, preferably 100 μm or less.
[0036]
【The invention's effect】
According to the present invention, since it is possible to immediately detect that the atmospheric oxygen is very small in the machine, the apparatus constituent members are not exposed to the atmospheric oxygen leaked into the machine from outside for a long period of time. For this reason, there is no longer a serious accident that the member penetrates through the corrosion.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a gas leak sensor used in the present invention.
FIG. 2 is an explanatory diagram of an absorption refrigerator according to the present invention.
FIG. 3 is an explanatory diagram showing an installation state of a gas leak sensor.
FIG. 4 is an explanatory diagram showing the occurrence of cracks.
FIG. 5 is an explanatory diagram of a modified embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High temperature regenerator 1B Gas burner 2 Low temperature regenerator 3 Condenser 4 Evaporator 5 Absorber 6 Low temperature heat exchanger 7 High temperature heat exchanger 8-11 Absorbing liquid pipe 13 Absorbing liquid pump 14-18 Refrigerant pipe 19 Refrigerant pump 21 Cold / hot water pipe 22 Cold / Hot Water Pump 23 Cooling Water Pipe 24/25 Pressure equalizing Pipe 26-31 Open / Close Valve 32 Socket 32A Screw 33 Vacuum Pump 34 Open / Close Valve 35 Vacuum Pull Pipe 36 Extraction Device 37 Ejector 38/39 Extraction Pipe 100 Gas Leak Sensor 101 Mounting Member 101A Screw 102A Electrode 102B Electrode 103 Fine wire

Claims (3)

A gas leak sensor comprising two electrodes spaced apart and supported in a circuit in which refrigerant vapor circulates, and a thin line stretched between the two electrodes, and a refrigerant in which the thin line flows inside the refrigerant pipe An absorption refrigerator installed so as to be in contact with steam , wherein an on-off valve is installed in a refrigerant vapor circuit upstream of the gas leak sensor and a refrigerant vapor circuit downstream of the gas leak sensor. Absorption refrigerator. Absorption refrigerating machine according to claim 1, wherein the exhaust means is connected to refrigerant vapor circuit gas leak sensor is installed between each other off valve. The absorption refrigerator according to claim 1 or 2 , wherein the absorption liquid of the absorption refrigerator is an aqueous solution of a salt containing a halogen element system.

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