JP2007327662A - Maintenance method of absorption-type refrigerating machine and cooling freezing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a maintenance method of an absorption type refrigerating machine and a cooling freezing device capable of shortening a time for maintenance work and reducing maintenance work by surely generating an ice plug in piping even when an absorbent is mixed in the aqueous solution. <P>SOLUTION: In this maintenance method of the absorption-type refrigerating machine 1 in which various devices including a pump 19 constituting a refrigerating cycle, are sealed and connected so that the absorbent solution obtained by mixing the refrigerant and the absorbent can be circulated, the cooling freezing device including a coolant container 3 opened to the atmospheric air at its upper part, is disposed on both piping portions 24, 24A connected to an inlet and outlet of the pump 19, and both piping parts 24, 24A are cooled from the circumference while injecting the coolant into the coolant container 3, thus the refrigerant and the absorbent solution in both piping parts 24, 24A are frozen, and then at least one or more works of inspection, repair and replacement of the pump is executed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an absorption refrigerator maintenance method and a cooling freezing apparatus used for the maintenance method.

  In the conventional absorption refrigerator, when performing maintenance work related to inspection, repair and replacement of various devices including the pump constituting the refrigeration cycle, especially when performing inspection, repair and replacement of the pump. In order to prevent metal corrosion in the absorption chiller, the refrigerant and absorbent solution in the absorption chiller are replaced with nitrogen gas. The nitrogen gas fills the machine and slightly leaks from the opening (repair work section). In this way, the pump is inspected, repaired, and replaced after the atmosphere does not enter the machine, and after the inspection, repair, and replacement are completed, the nitrogen in the absorption refrigerator is again converted into the refrigerant and the absorbent solution. I was trying to replace it. For this reason, the maintenance work time of the pump has been prolonged. In addition, it is necessary to replace the refrigerant and absorbent solution in the absorption refrigerator with nitrogen, or to replace the nitrogen in the absorption refrigerator with refrigerant and the absorbent solution, thus reducing maintenance work. I could not.

Therefore, as a maintenance method such as repair or replacement of existing piping, the existing fluid in the existing piping is temporarily frozen across the location where maintenance is required without removing the internal fluid in the existing piping. There has been proposed an ice plug that is formed inside the pipe so that the existing pipe is repaired or replaced without removing the internal fluid flowing through the existing pipe (see, for example, Patent Document 1).
JP 2000-65281 A (paragraph number 0003 to paragraph 0004 and paragraph number 0008, FIGS. 3 and 5)

  However, in the maintenance method for existing piping described in JP 2000-65281 A, an internal fluid that flows through the existing piping is provided by providing a jacket that covers the periphery of the existing piping and circulating the coolant in the jacket. An ice plug is formed by a pipe freezing mechanism that freezes the pipe. However, if the fluid flowing in the existing pipe is an aqueous solution in which a refrigerant and an absorbent are mixed, sufficient sealing performance is provided in the existing pipe. It has been found that ice plugs with (sealing properties) cannot be produced. Therefore, in the absorption chiller, the ice plug is generated by freezing the fluid flowing in the existing pipe by the pipe freezing mechanism described in JP 2000-65281 A, and thus connected to the existing pipe. It has not been done to remove the equipment and perform maintenance work on the equipment. As a result, the maintenance work of the pump that is a device constituting the refrigeration cycle of the absorption chiller is a method of replacing the refrigerant and the absorbent solution in the absorption chiller with nitrogen as in the conventional absorption chiller. Therefore, the maintenance work time has not been shortened and the maintenance workability has not been reduced.

  The present invention has been made in view of the actual situation in the prior art described above, and its purpose is to make it possible to generate an ice plug in a pipe even in an aqueous solution in which an absorbent is mixed. An object of the present invention is to provide a maintenance method for an absorption chiller that allows inspection, repair, and replacement of a pump constituting the absorption chiller without extracting refrigerant and absorbent solution in the chiller. In addition, an object of the present invention is to provide an ice plug in a pipe reliably even in an aqueous solution mixed with an absorbent, and a cooling freezing apparatus suitable for carrying out an absorption refrigerator maintenance method. Is to provide.

  In order to achieve the above object, the present invention is formed by hermetically connecting the various devices so that the refrigerant and the absorbent solution can be circulated in the various devices including the pump constituting the refrigeration cycle. In the absorption refrigerator maintenance method, a cooling / freezing device including a coolant container that is open to the atmosphere is disposed on both pipes connected to the inlet / outlet of the pump, and the coolant container is cooled. By cooling both pipe parts from the surroundings while injecting the agent, the refrigerant or absorbent solution is frozen in both pipe parts to generate an ice plug, and then the pump is inspected, repaired and replaced. It is characterized in that at least one or more operations are performed.

  Furthermore, the present invention is characterized in that the coolant is injected into the coolant container so that the piping portion in the coolant container is maintained in an immersed state by the coolant.

  Furthermore, in order to achieve the above object, the present invention provides a cooling and freezing apparatus used in a maintenance method for an absorption chiller so that both pipe parts connected to the inlet / outlet of the pump surround the pipe parts. A coolant container that is open to the atmosphere, a coolant transfer pipe connected to the coolant container, a flow control valve connected to the coolant transfer pipe, and a flow control valve The present invention is characterized in that at least a coolant cylinder connected via a take-out device is provided.

  Furthermore, the present invention provides the coolant container as a bottomed cylindrical body having an open top, and the cylindrical body has a two-part structure that can sandwich the pipe portion, and a mating surface of the two-part structure. After bonding with a soft adhesive for low temperature, an adhesive tape is adhered to the outer periphery of the bonded portion.

  According to the present invention, even in an aqueous solution in which an absorbent is mixed, an ice plug can be reliably generated in the pipe, and the absorption type can be obtained without extracting the refrigerant and the absorbent solution in the absorption refrigerator. There is a maintenance method for absorption refrigerators that enables inspection, repair, and replacement of pumps that make up the refrigeration cycle of the refrigerator, which can significantly reduce maintenance work time and reduce maintenance workability. can get. Furthermore, according to the present invention, a cooling and freezing apparatus suitable for maintenance of an absorption refrigerator can be obtained with a simple structure capable of reliably generating an ice plug in a pipe.

  Hereinafter, an absorption refrigerator maintenance method and cooling freezing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a cooling freezing apparatus used in a maintenance method for an absorption refrigerator according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of an absorption refrigerator according to an embodiment of the present invention. FIG. 3 is an explanatory diagram of a maintenance method for an absorption refrigerator according to an embodiment of the present invention. FIG. 4 is an enlarged perspective view of a main part of a cooling / freezing device used in the maintenance method for the absorption refrigerator according to the embodiment of the present invention.

  The cooling freezing apparatus 2 used in the maintenance method of the absorption refrigerator 1 according to the embodiment shown in FIG. 1 is a coolant that is attached to a piping location where the ice plug (ice soul) A is to be generated in the absorption refrigerator 1. A container 3, a coolant transfer pipe 4 connected to the coolant container 3, a flow control valve 5 connected to the coolant transfer pipe 4, and a flow control valve 5 connected to the flow control valve 5 via a take-out device 6. The coolant cylinder 7, the temperature sensor 8 attached to the piping location where the ice plug A is to be generated, the temperature sensor 8 attached in the vicinity of the piping location where the ice plug A is desired to be generated, and the piping where the ice plug A is desired to be generated The pressure gauge 9 which detects the pressure change in the apparatus which comprises the refrigerating cycle of the absorption refrigeration machine connected to the location is provided at least.

  As shown in FIG. 2, the absorption refrigerator 1 includes a heating source 10 such as a burner, and a high-temperature regenerator 11 that generates refrigerant vapor by heating an aqueous solution (mixed aqueous solution of absorption liquid and refrigerant) by the heating source 10. A low-temperature regenerator 12 for generating a refrigerant vapor by heating the aqueous solution inside using the refrigerant vapor generated in the high-temperature regenerator 11 as a heating source, and the refrigerant vapor generated in the low-temperature regenerator 12 in the heat transfer tube 13. By cooling with the cooling water W1 flowing through the condenser 14, the condenser 14 to be condensed and liquefied, the refrigerant liquid condensed by the condenser 14 is introduced and evaporated, and heat is taken from the cooling water W2 flowing through the heat transfer pipe 15. The evaporator 16 to be cooled and the refrigerant vapor evaporated by the evaporator 16 are passed through an illuminator (filter) 17 and then cooled by the cooling water W1 flowing in the heat transfer tube 13, while the cooling is performed. An absorber 18 that absorbs the vapor into the aqueous solution flowing from the high-temperature regenerator 11 and the low-temperature regenerator 12, a first pump (refrigerant spray pump) 19 for spraying the refrigerant liquid of the evaporator 16, A second pump (solution spray pump) 20 for spraying the aqueous solution, a third pump (solution circulation pump) 21 for supplying the aqueous solution of the absorber 18 to the high temperature regenerator 11 and the low temperature regenerator 12, A high temperature heat exchanger 22 that exchanges heat between the aqueous solution flowing into the high temperature regenerator 11 and the aqueous solution exiting from the high temperature regenerator 11, and a low temperature that exchanges heat between the aqueous solution flowing into the low temperature regenerator 12 and the aqueous solution exiting from the low temperature regenerator 12. The exchanger 23 constitutes a refrigeration cycle.

  When it is desired to perform maintenance related to inspection, repair or replacement of the first pump (refrigerant spray pump) 19 of the absorption chiller 1, it is connected to the inlet / outlet of the first pump 19 as shown in FIG. The coolant container 3 is attached to each of the two pipe portions 24 and 24A, and the cooling and freezing device 2 is installed so that the coolant N can be injected into the coolant container 3. Injection of the coolant N into the coolant container 3 is simultaneously performed by an injection tube 4A connected to the coolant transfer tube 4 of the cooling freezing device 2. As the coolant N, for example, liquid nitrogen is used. Here, the term “maintenance” refers to the work of replacing, repairing or inspecting the parts constituting the first pump 19 as well as the operation of exchanging, repairing or inspecting the entire first pump 19. This includes cases where

  As shown in FIG. 4, the coolant container 3 is a circular or square cylindrical body 3A with a bottom open to the atmosphere, and the cylindrical body 3A sandwiches the piping parts 24 and 24A. In addition, after bonding the split surface 3B of the split structure with a soft adhesive for low temperature, an adhesive tape 25 is adhered to the outer periphery of the bonded portion. The cylindrical body 3A of the coolant container 3 is provided with a waterproof coating made of aluminum foil, polyester film or the like on the outer peripheral wall, and the inner peripheral wall is made of rigid urethane foam. The temperature sensor 8 is attached to the outer peripheral wall in the vicinity of the pipe portion 24 to which the first pump 19 is connected. The pressure gauge 9 is provided so as to detect a pressure change in the first pump 19.

  Next, the maintenance method of the absorption refrigerator 1 using the cooling freezer 2 will be described in detail.

  First, as shown in FIG. 1 to FIG. 3, a coolant container 3 is attached to each of the pipe portions 24 and 24 </ b> A connected to the inlet / outlet of the first pump 19 that is the object of maintenance, and cooling is performed. The cooling / freezing device 2 is installed so that the injection pipe 4 </ b> A connected to the coolant transfer pipe 4 can be inserted into the coolant container 3 from the upper end opening of the agent container 3.

  Next, the aqueous solution mixed with the absorbent flowing through the pipe portions 24 and 24A is sampled from the valve in the vicinity of the first pump 19 that is the object of maintenance, and the concentration of the aqueous solution is measured. The freezing temperature of the aqueous solution whose concentration has been measured is confirmed and recorded in advance using the concentration aqueous solution concentration curve.

  Next, the flow rate adjusting valve 5 of the coolant transfer pipe 4 is opened, and the coolant N is simultaneously injected into the two coolant containers 3. And the injection | pouring is carried out until the coolant level is located above the upper surface of the piping parts 24 and 24A so that the piping parts 24 and 24A in the coolant container 3 are maintained in the immersed state by the coolant N. Done.

  Next, the coolant N is injected into the coolant container 3, and after a lapse of a certain time, the pressure gauge 9 changes the pressure in the first pump 19 (if the aqueous solution is ice lump, the pressure drops, and the refrigerant In the case of an ice block, the pressure rises) is detected, and the temperature detected by the temperature sensor 8 at the time of detection is confirmed. And if the detected temperature of the confirmed temperature sensor 8 becomes lower than the freezing temperature of the aqueous solution previously confirmed, it is determined that the ice plug A is completed.

  Next, when the ice plug A is completed, the maintenance work such as inspection, repair, and replacement is performed by disconnecting the first pump 19 that is the object of maintenance from the absorption refrigerator 1. During the maintenance work, the coolant N is continuously injected into the coolant container 3 so that the coolant N does not flow out of the upper end opening of the coolant container 3.

  Next, when the maintenance work of the first pump 19 is completed, the first pump 19 is incorporated into the absorption refrigerator 1 and the injection of the coolant N into the coolant container 3 is stopped to cool the first pump 19. Clear the freezing device 2.

  Finally, a pressure test or the like of devices constituting the refrigeration cycle of the absorption refrigeration machine 1 is performed, and the maintenance work of the absorption refrigeration machine 1 can be completed when the pressure test or the like is passed.

  According to the maintenance method of the absorption chiller 1 of the above embodiment, after extracting the refrigerant and the absorbent solution in the absorption chiller 1, without performing work such as sealing nitrogen in the refrigerator 1 By removing the first pump 19 from the absorption refrigeration machine 1, the first pump 19 can be inspected, repaired and replaced, so that the maintenance work time can be greatly shortened and the maintenance workability can be reduced. Can be achieved.

  Furthermore, according to the cooling / freezing device 2 used in the maintenance method of the absorption refrigerator 1 of the above embodiment, the coolant container 3 is open to the atmosphere, so the coolant injected into the coolant container 3. Since the evaporation of N is actively performed, the pipe parts 24 and 24A are rapidly cooled, and the aqueous solution mixed with the absorbent flowing through the pipe parts 24 and 24A is surely frozen, and the pipe parts 24 and 24A. Inside, the ice plug A having a sufficient sealing property (sealing property) can be quickly generated as shown in FIG.

  Further, in the maintenance method of the absorption refrigerator 1 of the above embodiment, the coolant N is placed in the coolant container 3 so that the coolant level of the coolant N is located above the upper surfaces of the pipe portions 24 and 24A. Since the entire outer periphery of the pipe parts 24, 24A is cooled by the coolant N, the ice plug A can be generated more quickly and stably in the pipe parts 24, 24A. it can.

  Furthermore, according to the cooling freezing apparatus 2 used in the maintenance method of the absorption chiller 1 of the above embodiment, the pressure sensor 9 detects the pressure change in the first pump 19 and then detects it by the temperature sensor 8. By confirming that the temperature is equal to or lower than the freezing temperature of the aqueous solution previously confirmed, it is possible to know that the ice plug A is completed, and in both the pipe portions 24 and 24A. Since the ice plug A is generated at the same time, the maintenance work of the absorption refrigerator 1 is performed smoothly.

  In the above embodiment, the ice plug A is generated in both the pipe portions 24, 24 A connected to the inlet / outlet of the first pump 19, and the maintenance work of the first pump 19 is performed. Also for the second pump 20 and the third pump 21, the positions shown in FIG. 2, that is, in the case of the second pump 20, in the positions indicated by the symbols B 1 and B 2, and in the case of the third pump 21. If the coolant container 3 is attached to the positions indicated by reference numerals C1 and C2, respectively, both pipe portions connected to the inlets and outlets of the second pump 20 and the third pump 21 are cooled. Maintenance work can be performed in the same manner as the first pump 19.

It is a figure which shows schematic structure of the cooling freezing apparatus used for the maintenance method of the absorption refrigerator which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the absorption refrigerator which concerns on one Embodiment of this invention. It is a figure explaining the maintenance method of the absorption refrigerating machine concerning one embodiment of the present invention. It is a principal part expansion perspective view of the cooling freezing apparatus used for the maintenance method of the absorption refrigerator which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Absorption type refrigerator 2 Cooling freezing device 3 Coolant container 3A Cylindrical body 3B Matching surface 4 Coolant transfer pipe 4A Injection pipe 5 Flow control valve 6 Simple extraction device 7 Coolant cylinder 8 Temperature sensor 9 Pressure gauge 10 Heating source 11 High temperature regenerator 12 Low temperature regenerator 13 Heat transfer tube 14 Condenser 15 Heat transfer tube 16 Evaporator 17 Eluminator 18 Absorber 19 First pump 20 Second pump 21 Third pump 22 High temperature heat exchanger 23 Low temperature exchanger 24, 24A Piping part 25A Adhesive tape A Ice plug N Coolant

Claims (4)

  In a maintenance method for an absorption chiller in which the various devices are hermetically connected so that the refrigerant and the absorbent solution can be circulated through the various devices including the pump constituting the refrigeration cycle, A cooling / freezing device including a coolant container that is open to the atmosphere is arranged on both pipe parts connected to the inlet / outlet, and the pipe parts are connected from the surroundings while injecting the coolant into the coolant container. By cooling, the refrigerant or absorbent solution is frozen in both pipe parts to generate an ice plug, and then at least one of inspection, repair, and replacement of the pump is performed. An absorption refrigerator maintenance method characterized by the above.   The absorption type according to claim 1, wherein the pipe portion in the coolant container is injected with the coolant into the coolant container so that the immersion state is maintained by the coolant. Maintenance method of the refrigerator.   A cooling and freezing apparatus used in the maintenance method for an absorption chiller according to claim 1 or 2 is disposed so as to surround each of the pipe parts connected to the inlet / outlet of the pump so that the upper part is in the atmosphere. An open coolant container, a coolant transfer pipe connected to the coolant container, a flow rate control valve connected to the coolant transfer pipe, and a flow control valve connected to the flow rate control valve via a take-out device A cooling and freezing apparatus characterized by comprising at least a coolant cylinder. The coolant container is a bottomed cylindrical body having an open top, and the cylindrical body has a split structure that can sandwich the pipe portion, and the mating surface of the split structure is a soft type for low temperature use. 4. The cooling and freezing apparatus according to claim 3, wherein an adhesive tape is attached to the outer periphery of the bonded portion after bonding with an adhesive.

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