JP2008180443A - Cooling storage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling storage capable of effectively reducing noise of a positive-displacement circulation pump disposed in a circulation circuit, in transmitting waste heat radiated by a refrigerating device to a prescribed part through the circulation circuit. <P>SOLUTION: This cooling storage 1 cools a storage compartment in a heat insulating housing 10 by a Stirling refrigerating machine 110. The waste heat radiated from the Stirling refrigerating machine 100 is transferred to a dew-proofing portion 16 of the heat insulating housing 10 by a high temperature-side second circulation circuit 150. The high temperature-side second circulation circuit 150 circulates a refrigerant by a circulation pump 157 as a positive-displacement pump. A suction-side gas-liquid separator 158 is disposed at a suction side of the circulation pump 157, and a discharge-side gas-liquid separator 159 is disposed at a discharge side. Long axes of the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159 are respectively inclined so that their upper parts are applied as inlet sides and lower parts are applied as outlet sides. The circulation pump 158, the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159 are received in a sound insulation space 180. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cooler that cools the interior of a refrigerator with a cooling unit of a refrigerating apparatus and transmits waste heat radiated from the refrigerating apparatus to a predetermined place by a refrigerant circulation circuit. “Refrigerator” as used herein is a concept that generally refers to a device that lowers the temperature of food and other articles. Products such as “refrigerator” “freezer” “freezer refrigerator” “showcase” “vending machine” It doesn't matter the name.

  Specific chlorofluorocarbons (CFC: chlorofluorocarbon) and alternative chlorofluorocarbons (HCFC: hydrochlorofluorocarbon, HFC: hydrofluorocarbon) are used as refrigerants in the refrigeration cycle of the refrigerator. Among these refrigerants, CFCs and HCFCs are subject to international regulations for their production and use because they are, to some extent, lead to the destruction of the ozone layer. In addition, HFC that does not destroy the ozone layer also has a problem of promoting global warming.

  Therefore, Stirling refrigerators that do not use ozone-depleting substances as a refrigerant are in the spotlight. In a Stirling refrigerator, an inert gas such as helium is used as a working medium, and a piston and a displacer are operated by external power to repeatedly compress and expand the working medium, thereby increasing the temperature of the high-temperature head and lowering the temperature of the low-temperature head. The high-temperature head radiates heat to the surrounding environment, and the low-temperature head radiates heat from the interior.

  When performing heat dissipation and heat absorption with a Stirling refrigerator, a refrigerant (heat transport medium) accompanied by a gas-liquid phase change is often used. That is, a high temperature side evaporator is attached to the high temperature head, and the refrigerant in the high temperature head is evaporated by the heat. The evaporated refrigerant is sent to the high temperature side condenser, where it dissipates heat and liquefies, and returns to the high temperature side evaporator. A low-temperature side condenser is attached to the low-temperature head, and the refrigerant therein is condensed with cold heat. The condensed refrigerant is sent to the low temperature side evaporator, where it absorbs heat and vaporizes, and returns to the low temperature side condenser.

  The example of the refrigerator which circulates a refrigerant | coolant as mentioned above and transmits the heat and cold of a Stirling refrigerator can be seen in patent document 1. FIG. In Patent Document 1, the heat of the high-temperature head is recovered with a liquid refrigerant, and the refrigerant flows through a dew-proof pipe stretched around a location (dew-proof portion) where condensation is necessary, such as an opening of a cooling chamber. A configuration is disclosed in which the temperature does not drop below the dew point.

  Condensation prevention piping passes through the surroundings of the opening of the heat insulation housing of the refrigerator and the partition in the heat insulation housing in a complicated manner, and it obstructs the flow of liquid refrigerant, which is thin, has many bent parts, and has a large height difference. Factors are complete. Accordingly, a positive displacement pump with a high driving pressure, such as a cylinder system or a diaphragm system, is suitable as a circulation pump for circulating the refrigerant through the dew-proof pipe.

Examples of positive displacement pumps can be found in US Pat. Patent Document 2 describes a type in which a rolling piston in a cylinder block is eccentrically rotated by a crank pin. Patent Document 3 describes a piezoelectric vibrator pump.
JP 2006-214709 A Japanese Patent No. 3739808 Japanese Utility Model Publication No. 62-45385

  The positive displacement pump pumps out fluid by a combination of a driving body that changes the volume of the internal space and a check valve. When the fluid is liquid, it is inevitable that pulsation occurs in the pressure in the pipe. Pressure pulsation causes the piping system to vibrate and generates noise.

  Further, in the case of using a gas-liquid refrigerant like the positive displacement pump of Patent Document 2, vaporization and liquefaction of the refrigerant are in an equilibrium state, and noise and vibration due to cavitation are likely to occur due to a local pressure difference.

  In order to reduce the problem of pressure pulsation and cavitation, Patent Documents 1-3 have various ideas.

  In Patent Document 1, the tertiary refrigerant circuit in which the tertiary refrigerant circulates is configured as a circulation circuit independent of the secondary refrigerant circulation circuit connected to the high-temperature side evaporator, and cavitation is generated in the pump that forcibly circulates the liquid tertiary refrigerant. It is possible to suppress the occurrence.

  In Patent Document 2, a pulsation mitigating container is provided on the discharge side of the positive displacement pump.

  In Patent Document 3, a storage tank for storing air is provided on the discharge side of the piezoelectric vibrator pump.

  However, it is difficult to say that the configuration described in Patent Documents 1-3 is sufficiently exhausted in terms of preventing noise caused by pressure pulsation and cavitation from being heard outside.

  Although the configuration of Patent Literature 1 can suppress the occurrence of cavitation, no special consideration has been given to alleviating pressure pulsation.

  In the configurations of Patent Documents 2 and 3, pressure pulsation can be reduced on the discharge side by a pulsation reducing container or a storage tank provided in the immediate vicinity of the pump discharge port. However, it cannot be said that the pressure pulsation on the suction side of the pump can be sufficiently relaxed.

  As shown in FIG. 2 of Patent Document 3, there is a configuration in which a volume variable space in which gas is enclosed by a diaphragm (balloon) is provided. In that case, the natural frequency of the diaphragm is set to be equal to or lower than the pump driving frequency, and further, There are many conditions that must be satisfied, such as the need for displacement that absorbs the variable volume, and the need to use a material that does not allow the refrigerant to pass through for a long period of time. Is difficult.

  Moreover, in the structure of patent document 2, a sheathed heater is wound around the outer periphery of a pulsation relaxation container, and the liquid refrigerant in a container is evaporated and it is set as a gas refrigerant. The enclosure that surrounds the container is provided with an air opening, and when the outside air temperature is high, outside air is taken in around the container to reduce the power consumption of the sheathed heater, but this configuration reduces the sound insulation. . On the other hand, noise may be scattered outside through the air vent.

  The present invention has been made in view of the above points, and in transmitting waste heat radiated from the refrigeration apparatus to a predetermined location in the circulation circuit, it is possible to effectively suppress noise of the positive displacement circulation pump installed in the circulation circuit. The purpose is to provide a refrigerator.

  (1) In order to achieve the above object, the present invention cools the inside of the warehouse with the cooling unit of the refrigeration apparatus, and transmits the waste heat radiated by the refrigeration apparatus to a predetermined place with a circulation circuit. The circuit circulates the refrigerant with a positive displacement pump, and is characterized in that a suction side gas-liquid separator is provided on the suction side of the circulation pump, and a discharge side gas-liquid separator is provided on the discharge side. .

  According to this configuration, by providing the gas-liquid separator on each of the suction side and the outlet side of the positive displacement circulation pump, the gas stored in the gas-liquid separator can be used for the suction-side piping of the circulation pump. Also for the piping, pressure pulsation can be reduced.

  If the internal pressure of the circulation circuit is adjusted to be equal to or higher than the atmospheric pressure at the position of the circulation pump, cavitation due to the drive of the circulation pump can be suppressed.

  By providing a gas-liquid separator, pulsation is eliminated, and intermittent liquid feeding becomes smooth, so that the flow rate of the circulation pump can be increased, and when using the gas-liquid separator for a pulsation mitigation container, There is no need to provide a diaphragm.

  (2) Further, according to the present invention, in the refrigerator configured as described above, the suction-side gas-liquid separator and the discharge-side gas-liquid separator are each inclined with the major axis of the container inclined upward, the upper side being the inlet side, and the lower side being the outlet It is characterized by being on the side.

  Since a gas-liquid separator is a structure that requires a certain amount of volume and length, if the major axis of the container is arranged vertically, the arrangement space will bite into the storage space of the refrigerator, and both spaces The amount of heat insulation layer necessary to separate the gaps also increases. If the major axis of the gas-liquid separator is inclined as in this configuration, it is easy to design an arrangement space that does not bite into the storage space of the refrigerator. And by tilting the vessel body, the cross-sectional area of the flow path can be increased and the water surface can be widened, so that the flow rate can be reduced compared to the main piping portion of the circulation circuit, and gas-liquid separation can be sufficiently performed.

  (3) Moreover, this invention is characterized by the nitrogen storage gas being filled with the gas storage space of the said gas-liquid separator in the refrigerator of the said structure.

  Nitrogen gas is safe and inexpensive, and is inert, so it does not corrode the circulation circuit piping or circulation pump. In addition, if the gas is easily dissolved in the water-based refrigerant, the tendency to dissolve in the refrigerant on the discharge side of the high-pressure circulation pump and to escape from the refrigerant on the suction side of the low-pressure circulation pump becomes significant, and the disappearance and generation of bubbles is noisy. However, since nitrogen gas is difficult to dissolve in water-based refrigerant, there is no concern for it.

(4) Moreover, in the refrigerator having the above-described configuration, the present invention provides a gas storage capacity of the suction side gas-liquid separator,
(Gas volume at the time of sealing) × {Atmospheric pressure ÷ (Atmospheric pressure−Differential pressure generated in the circulation circuit by the circulation pump)}
It is characterized by being smaller than the value of the expression represented by.

  When the circulation pump is operated, the discharge-side gas-liquid separator is pressurized by the differential pressure generated in the circulation circuit by the circulation pump, and the internal gas is compressed to reduce the volume. On the contrary, the suction side gas-liquid separator is depressurized, and the gas inside expands to increase the volume. In addition, a phenomenon occurs in which the sealed gas is transferred from the discharge side gas-liquid separator to the suction side gas-liquid separator. This is because the gas is dissolved in the refrigerant in the discharge-side gas-liquid separator that is at a high pressure, and the gas escapes from the refrigerant in the suction-side gas-liquid separator that is at a low pressure. If the circulation pump is operated for a long time, most of the gas sealed in the circulation circuit is transferred to the suction side gas-liquid separator. If the gas storage capacity of the suction-side gas-liquid separator is too large, the gas in the discharge-side gas-liquid separator is exhausted, and the discharge-side gas-liquid separator loses the ability to relieve pressure pulsation. Therefore, the gas storage capacity of the suction-side gas-liquid separator must be calculated from the volume of all the enclosed gas in the initial state, taking into account the expansion of the enclosed gas due to the pump differential pressure. The condition is satisfied by making the gas storage capacity of the suction side gas-liquid separator smaller than the value of the above formula.

  The liquid level in the suction-side gas-liquid separator during the circulation pump operation is finally stabilized in the vicinity of the gas-liquid separation boundary, in other words, in the vicinity of the height of the outlet upper end of the suction-side gas-liquid separator. In this state, there is a possibility that the gas in the suction side gas-liquid separator flows out from the outlet, that is, overflows, but the amount of overflow is small and the circulation pump temporarily sucks the bubbles, but the bubbles immediately It is discharged and trapped in the discharge side gas-liquid separator. For this reason, the circulation system is immediately stabilized.

  (5) Further, in the refrigerator having the above-described configuration, the present invention provides a total volume of the internal gas of the suction-side gas-liquid separator and the internal gas of the discharge-side gas-liquid separator when the refrigerant in the circulation circuit is completely frozen. It is characterized by exceeding the volume expansion of.

  According to this configuration, even if the refrigerant in the circulation circuit is frozen due to a cold climate, the volume expansion is due to compression of the internal gas of the suction side gas-liquid separator and the internal gas of the discharge side gas-liquid separator. Since it is absorbed, pipe rupture can be avoided.

  (6) Further, the present invention is characterized in that, in the refrigerator having the above-described configuration, a charging unit that encloses gas in the circulation circuit is provided in a section from the circulation pump to the discharge-side gas-liquid separator. Yes.

  In the configuration in which the suction side gas-liquid separator is provided on the suction side of the circulation pump and the discharge side gas-liquid separator is provided on the discharge side, it is necessary to store gas in both gas-liquid separators. If a charging unit is provided in the section from the circulation pump to the discharge side gas-liquid separator as in this configuration, when the gas is charged while the circulation pump is operated, the gas is first stored in the gas storage space of the discharge side gas-liquid separator. Go meet. The gas filling the gas storage space of the discharge side gas-liquid separator overflows, goes through the path, flows to the suction side gas-liquid separator, and is trapped there. If the amount of gas to be charged is appropriate, the gas will not overflow from the suction side gas-liquid separator.

  If an amount of gas that causes overflow from both the discharge-side gas-liquid separator and the suction-side gas-liquid separator is filled, the gas overflows to pipes other than the gas-liquid separator. For example, assuming that the surplus gas amount is 20 ml and the inner diameter of the pipe is 5 mm, the gas fills a portion of about 1 m of the pipe, and the refrigerant in that section is excluded. If the circulation pump has a low self-priming capacity, it will easily fall into a state where it cannot be fed. If the position of the charging unit is set as described above and the gas amount is set appropriately, such a situation does not occur, and therefore a circulation pump having a low self-priming capability can be employed.

  (7) Moreover, the present invention is characterized in that, in the refrigerator having the above-described configuration, a filter for collecting foreign matter in the refrigerant is provided in the suction-side gas-liquid separator.

  In addition to dust and material cutting powder that entered the manufacturing circuit, the circulating circuit includes oxide scales that have formed on the inner wall of the pipe over time, impurities and additives that precipitate when low-purity antifreeze is mixed in the refrigerant, etc. There are various solid foreign substances. When these foreign substances are sucked into the positive displacement circulation pump, the foreign substances are caught in the valve and the liquid feeding capacity is lowered. In order to prevent this, it is preferable to provide a filter at a position as close as possible to the suction side of the circulation pump. The suction side gas-liquid separator just satisfies this condition. Further, since the gas-liquid separator has an inner diameter larger than that of a normal pipe portion, a filter having a large filtration area can be installed, and the flow path resistance does not need to be increased so much.

  (8) Moreover, the present invention is characterized in that in the cooler configured as described above, a sound insulation space is formed to accommodate the circulation pump, the suction side gas-liquid separator, and the discharge side gas-liquid separator.

  According to this configuration, since the element that generates vibration and accompanying noise is accommodated in the sound insulation space, it is possible to realize noise reduction of the refrigerator.

  According to the present invention, by providing a gas-liquid separator on each of the suction side and the outlet side of the positive displacement circulation pump, the gas stored in the gas-liquid separator can be used for the suction-side piping of the circulation pump. As for piping, pressure pulsation can be reduced and noise can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 is a front view of the refrigerator, FIG. 2 is a front view of the refrigerator with the heat insulating door removed, FIG. 3 is a vertical sectional view of the refrigerator, FIG. 4 is a vertical sectional view of the refrigerator at different locations, FIG. Is an explanatory diagram of the structure of the cold air passage, FIG. 6 is a horizontal sectional view of the refrigerator cut along the line AA in FIG. 4, FIG. 7 is an enlarged horizontal sectional view of the vertical partition, and FIG. FIG. 9 is a partial vertical cross-sectional view of the Stirling refrigerator mounting portion of the refrigerator, FIG. 10 is a top view of the Stirling refrigerator supported by the support member, and FIG. 11 is a top view of the support member. 12 is a schematic perspective view of the cooling device, FIG. 13 is a sectional view showing the structure of the circulation pump and the gas-liquid separator, and FIG. 14 is a block diagram showing the flow of the cold air.

  The refrigerator 1 includes a heat insulating housing 10. The heat insulating housing 10 has a heat insulating layer formed by inserting a synthetic resin inner housing into a sheet metal outer housing and inserting a heat insulating material into a gap between the outer housing and the inner housing or foaming synthetic resin in the gap. Formed. Since the manufacturing method of such a heat insulation housing | casing is well-known and is not the main point of this invention, the detailed description is not carried out.

  The inside of the heat insulation housing 10 becomes a storage chamber. In this specification, “storage room” means a compartment in a refrigerated temperature zone (0 ° C. to 10 ° C.), a temperature zone slightly lower (up to minus 3 ° C.), “ice temperature”, “chill”, “partial” "High temperature zone and refrigeration temperature zone, excluding temperature zone where names such as", refrigeration temperature zone (minus tens of degrees or less), high temperature zone (for example, 50 to 80 ° C), refrigeration temperature zone It is a general term for spaces used for storage of food (including seasonings), medicines, cosmetics, etc., such as compartments in the middle temperature range.

  The storage chamber has an opening for taking in and out food on the front surface, and the opening is closed with a heat insulating door. As can be seen in FIG. 2, the storage chamber is divided into two parts by a horizontal partition 11. The space above and below the horizontal partition 11 is divided into left and right by the vertical partitions 12 and 13. In this specification, the left side of the observer facing the front surface of the heat insulating housing 10 is defined as the left side of the heat insulating housing 10, and the right side of the observer is defined as the right side of the heat insulating housing 10. Below the horizontal partition 11, the space on the left side of the vertical partition 13 is further divided into two parts by the horizontal partition 14.

  A space on the horizontal partition 11 and to the left of the vertical partition 12 is a first partition 15. A space on the horizontal partition 11 and to the right of the vertical partition 12 is a second partition 16. A space below the horizontal partition 14 and to the left of the vertical partition 13 is a third partition 17. A space below the horizontal partition 11 and to the right of the vertical partition 13 is a fourth partition 18. The 1st division part 15 and the 2nd division part 16 are used as a refrigerator compartment. The 3rd division part 17 and the 4th division part 18 are used as a freezer compartment. Between the horizontal partitioning parts 11 and 14, the space on the left of the vertical partitioning part 13 serves as a temperature switching partition part 19 that can be used as a refrigerator compartment or a freezer compartment. The second partition part 16 and the fourth partition part 18 are wider in the left-right direction than the first partition part 15, the third partition part 17, and the temperature switching partition part 19.

  A heat insulating door 20 (see FIG. 1) is provided at the front opening of the first partition 15, a heat insulating door 21 is provided at the front opening of the second partition 16, and a front opening of the third partition 17. Is provided with a heat insulating door 22, a heat insulating door 23 is provided at the front opening of the fourth compartment 18, and a heat insulating door 24 is provided at the front opening of the temperature switching compartment 19. The heat insulating doors 20, 22 and 24 rotate around a hinge portion provided on the left side, and the heat insulating doors 21 and 23 rotate around a hinge portion provided on the right side. An operation unit 25 for setting the temperature of each part in the storage room is provided below the heat insulating door 20.

  The first partition 15 is partitioned in the vertical direction by a three-stage shelf 30. A drawer-type case 31 is disposed under the lowest shelf 30.

  The second partition 16 is also partitioned in the vertical direction by the three-stage shelf 32. The lowermost shelf 32a has a depth dimension larger than the upper two steps, and underneath the drawer-type cases 33 and 34 are arranged in two upper and lower steps. A partition cover 35 (see FIG. 3) is provided for the upper surface opening of the lower case 34. The space between the lowermost shelf 32a and the partition cover 35 constitutes an isolation partition part 16a, and the space under the partition cover 35 constitutes an isolation partition part 16b. On the inner surface of the heat insulating door 21, a rack 36 for storing bottles, paper packs for beverages and the like is attached.

  Illumination is provided for each of the first partition 15 and the second partition 16. The illumination for the first partition 15 is a downlight 37 (see FIG. 4) disposed on the ceiling, and the illumination for the second partition 16 is an illumination panel 38 (see FIG. 4) disposed on the upper part of the back wall. 3). Both the downlight 37 and the illumination panel 38 use LEDs as light sources.

  A total of two cases 40a and 40b are inserted into the third partition part 17, and a total of three cases 41a, 41b and 41c are inserted into the fourth partition part 18 so as to overlap each other. The cases 40a and 40b are supported on the inner surface of the third partition 17 by the side edges, and the cases 41a, 41b and 41c are supported on the inner surface of the fourth partition 18 by the side edges, both of which are slid forward. Can be pulled out. A case 42 is inserted in the temperature switching section 19.

  An ice making unit 43 is disposed on the ceiling of the fourth partition 18 (see FIGS. 3 and 5). Ice produced by the ice making unit 43 is received by an ice container 44 (see FIG. 2) in the case 41a. A water supply tank 45 for supplying water to the ice making unit 43 is installed on the right side of the case 34 in the isolation section 16b.

  The 3rd partition part 17 and the 4th partition part 18 are divided as needed, and install an independent section specialized for ice making, or install an independent section suitable for various required temperature settings from quick freezing to thawing. It is possible to do.

  The storage chamber is cooled by the cooling device 100 of FIG. The central existence of the cooling device 100 is the Stirling refrigerator 110. The Stirling refrigerator 110 generates heat and cold by a reverse Stirling cycle. The heat is mainly taken out from the high temperature head 111 as waste heat, and the cold is taken out from the low temperature head 112.

  The Stirling refrigerator 110 includes components such as a displacer, a piston, and a linear motor that drives the piston, and the external shape is a rotating body having an axis. The Stirling refrigerator 110 is arranged with the axis line upright so that the high temperature head 111 is on the top and the low temperature head 112 is on the bottom. The power unit 113 containing the linear motor is located above the high temperature head 111.

  The high temperature side first circulation circuit 120 takes out the heat from the high temperature head 111 and dissipates it. In the high temperature side first circulation circuit 120, water (including an aqueous solution) or a hydrocarbon-based refrigerant is sealed as a secondary refrigerant. The “secondary refrigerant” is defined by defining the working medium inside the Stirling refrigerator 110 as “primary refrigerant” and the working medium used for heat transport outside the Stirling refrigerator 110 as “secondary refrigerant”. Incidentally, the “tertiary refrigerant” described later means a refrigerant that exchanges heat with the secondary refrigerant.

  The high temperature side first circulation circuit 120 is a thermosiphon circulation circuit that naturally circulates the secondary refrigerant, and the high temperature side evaporation mounted in a state where heat is transferred between the high temperature heads 111, that is, in a thermally connected state. And a secondary refrigerant pipe 123 that connects the high-temperature side evaporator 121 and the high-temperature side condenser 122 to the high-temperature side condenser 122 disposed on the Stirling refrigerator 110. The high temperature side condenser 122 functions as a heat exchanger for heat dissipation.

  The high-temperature side evaporator 121 is formed by forming a metal having good heat conductivity such as copper, copper alloy, or aluminum into a hollow ring shape. The high-temperature side evaporator 121 is fitted to the outer peripheral surface of the high-temperature head 111 and is thermally connected to the high-temperature head 111. A secondary refrigerant pipe 123 is led out from the side surface of the high temperature side evaporator 121. The secondary refrigerant pipe 123 extends upward after being led out from the side surface of the high-temperature side evaporator 121. And it is connected to the high temperature side condenser 122 above the Stirling refrigerator 110. The secondary refrigerant pipe 123 includes a gas phase pipe 123G that sends the vaporized secondary refrigerant to the high-temperature side condenser 122 and a secondary refrigerant that has condensed into a liquid in the high-temperature side condenser 122 to the high-temperature side. It is divided into a liquid phase pipe 123L that returns to the evaporator 121.

  The high temperature side condenser 122 has a structure in which a pipe 122a made of a metal material having good heat conductivity such as copper or copper alloy is bent, and a plurality of heat radiation fins 122b made of a metal material also having good heat conductivity are attached thereto. A heat radiating fan 124 for forced air cooling is combined with the high temperature side condenser 122.

  A low temperature side circulation circuit 130 is thermally connected to the low temperature head 112. The low temperature side circulation circuit 130 is filled with a natural refrigerant such as carbon dioxide (CO 2) as a secondary refrigerant. The low temperature side circulation circuit 130 includes a low temperature side condenser 131 mounted in a state of being thermally connected to the low temperature head 112, a low temperature side evaporator 132 installed in the heat insulating casing 10 of the refrigerator 1, and a low temperature side The secondary refrigerant | coolant piping 133 which connects the condenser 131 and the low temperature side evaporator 132 is included. The low temperature side evaporator 132 functions as a cooling unit of the cooling device 100.

  The low-temperature side condenser 131 is formed by forming a metal having good heat conductivity such as copper, copper alloy, or aluminum into a hollow ring shape. The low-temperature side condenser 131 is fitted to the outer peripheral surface of the low-temperature head 112 and is thermally connected to the low-temperature head 112. A secondary refrigerant pipe 133 is led out from the side surface of the low temperature side condenser 131. The secondary refrigerant pipe 133 is led out from the side surface of the low-temperature side condenser 131 and then extends downward. And it enters the inside of the heat insulation housing | casing 10, and is connected to the low temperature side evaporator 132. FIG. The secondary refrigerant pipe 133 is vaporized by the liquid phase pipe 133L that causes the low-temperature side evaporator 131 to flow into the low-temperature side evaporator 132 and the liquid-phase pipe 133L that flows into the low-temperature side evaporator 132. The secondary refrigerant is divided into a gas-phase pipe 133G for returning the secondary refrigerant to the low-temperature side condenser 131.

  Similarly to the high-temperature side condenser 122, the low-temperature side evaporator 132 is formed by bending a pipe 132a made of a metal material with good heat conductivity such as copper or a copper alloy and attaching a large number of heat-absorbing fins 132b made of a metal material with good heat conduction. Structure.

  When the Stirling refrigerator 110 is operated, the temperatures of the power unit 113, the high temperature head 111, and the high temperature side first circulation circuit 120 are increased. That is, these become the heat generating part of the cooling device 100. On the other hand, the temperature of the low temperature head 112 and the low temperature side circulation circuit 130 decreases. In the low temperature side circulation circuit 130, the low temperature side evaporator 132 serves as a cooling unit that takes heat away from the storage chamber.

  The cooling device 100 is mounted in the refrigerator 1 as follows.

  A recess is formed at the left or right corner above the rear surface of the heat insulating housing 10. This recessed portion becomes the machine room 46 (see FIGS. 4, 6, 9, and 12). In the present embodiment, the machine room 46 is provided at a position biased to the left when the heat insulating housing 10 is viewed from the front, that is, at a position on the left side of the back of the first partition portion 15. The machine room 46 includes a part of the cooling device 100, that is, a Stirling refrigerator 110, a high temperature side evaporator 121, a high temperature side condenser 122, a secondary refrigerant pipe 123, a heat radiation fan 124, a low temperature side condenser 131, and a secondary refrigerant. A part of the pipe 133 is accommodated. After all the elements to be accommodated are accommodated, the upper surface opening and the rear surface opening of the machine room 46 are closed by appropriate ventilation grills.

  Thus, the heat generating part of the cooling device 100 is adjacent to the first partition part 15 used as a refrigerator compartment having a higher temperature than the third partition part 17 and the fourth partition part 18 used as the freezer compartment. Therefore, compared with the case where it arrange | positions next to the 3rd division part 17 or the 4th division part 18, the heat insulation layer between can be made thin. Moreover, since the 1st division part 15 is a division part from which the temperature becomes higher than the 2nd division part 16 so that it may demonstrate later, it is hard to receive the influence from the heat generating part of the cooling device 100 more than the 2nd division part 16, and heat insulation between them. The layer can be made thinner.

  Furthermore, since the recess formed in the left or right corner above the back surface of the heat insulating housing 10 is the machine room 46 and the heat generating part of the cooling device 100 is disposed therein, the corner at the rear of the ceiling part of the storage room The entire portion does not protrude into the storage chamber, and the protrusion of the machine chamber 46 to the storage chamber becomes relatively small, so that the effective internal volume of the storage chamber can be increased.

  It is also possible to remove the heat insulation wall on the left side when viewed from the front of the machine room 46 and move the machine room 46 to the left side by the thickness of the heat insulation wall. In this way, the protrusion of the machine chamber 46 to the storage chamber is further reduced, the effective internal volume of the storage chamber is increased, and the volumetric efficiency is further improved.

  In supporting the Stirling refrigerator 110 inside the machine chamber 46, a support member 140 (see FIG. 11) is used. The support member 140 is a frame having a frame shape formed as a separate component from the heat insulating housing 10, and is horizontally fixed to an intermediate height of the machine room 46 by appropriate fixing means. Inside the support member 140, an opening 141 through which the Stirling refrigerator 110 and the secondary refrigerant pipe 123 of the high temperature side first circulation circuit 120 are passed is formed. In the opening 141, overhang portions 142 that support a vibration absorber described below are formed at four locations.

  A flange-like mounting leg 114 (see FIG. 10) formed by pressing a sheet metal is fixed to the outer surface of the power unit 113 of the Stirling refrigerator 110 by appropriate means such as welding. The mounting leg 114 is formed with four leg portions 114a whose tips are overlapped with the overhanging portion 142 of the support member 140 at four locations. Note that the mounting legs 114 are not limited to press-formed products. It may be a die-cast product, or may be a product obtained by injection molding a high strength synthetic resin material such as MC nylon.

  The Stirling refrigerator 110 is inserted from above into the opening 141 of the support member 140 in a posture in which the axis is vertical so that the low temperature head 112 comes to the bottom and the high temperature head 111 comes to the top. The weight of the Stirling refrigerator 110 is supported by the overhanging portion 142 supporting the leg portion 114a of the mounting leg 114. At this time, vibration absorbing means is interposed between the overhanging portion 142 and the leg portion 114a. . In the embodiment, a columnar vibration absorber 143 made of an elastic material such as rubber constitutes a vibration absorbing means.

  The vibration absorber 143 is required to support the Stirling refrigerator 110 at the center of the four overhang portions 142 so that the side surface of the power unit 113 does not contact the overhang portion 142. For this reason, the vibration absorber 143 is held by appropriate connecting means so as not to be displaced or dropped from between the overhanging portion 142 and the leg portion 114a. Known mechanical elements such as bolts, nuts, and washers can be used as the connecting means.

  The high temperature side first circulation circuit 120 is connected to the high temperature head 111 at a stage before the Stirling refrigerator 110 is attached to the support member 140. In this state, the portions of the low temperature head 112 and the high temperature head 111 of the Stirling refrigerator 110, the high temperature side evaporator 121, and a part of the secondary refrigerant pipe 123 are inserted into the opening 141 of the support member 140, and The leg portion 114 a is seated on the upper surface of the vibration absorber 143.

  The high temperature side condenser 122 is positioned above the Stirling refrigerator 110 while being supported by the secondary refrigerant pipe 123. In FIG. 8, only one gas-phase pipe 123G and one liquid-phase pipe 123L are shown. However, in an actual configuration, as shown in FIG. 10, two gas-phase pipes 123G and two liquid-phase pipes 123L are provided. It exists one by one.

  A heat radiating fan 124 is connected to the lower surface of the high temperature side condenser 122 via a duct 125. The blowing direction of the heat radiating fan 124 may be a direction in which wind is blown to the high temperature side condenser 122, or may be a direction in which wind is taken in through the high temperature side condenser 122.

  The low temperature side circulation circuit 130 is in a stage where the Stirling refrigerator 110 is attached to the support member 140 or in a stage where the low temperature head 112 passes through the opening 141 and protrudes under the support member 140 before that. Connected to the low temperature head 112.

  In the state where the assembly of the Stirling refrigerator 110 to the support member 140 and the connection of the high temperature side first circulation circuit 120 and the low temperature side circulation circuit 130 to the Stirling refrigerator 110 are completed, that is, in the state of FIG. The power unit 113 of the Stirling refrigerator 110 is disposed between the high temperature side condenser 122 and the high temperature side condenser 122. With this configuration, the height difference between the high-temperature side evaporator 121 and the high-temperature side condenser 122 can be secured large enough to allow the secondary refrigerant to circulate naturally. Thereby, while improving heat dissipation efficiency, since the space between the high temperature side evaporator 121 and the high temperature side condenser 122 is utilized for arrangement | positioning of the motive power part 113 of the Stirling refrigerator 110, space can be utilized effectively.

  In the state of FIG. 9, a heat radiating fan 124 that forcibly air-cools the high temperature side condenser 122 is also disposed between the high temperature side evaporator 121 and the high temperature side condenser 122. This configuration also helps to increase the height difference between the high temperature side evaporator 121 and the high temperature side condenser 122.

  The secondary refrigerant pipe 123 of the high temperature side first circulation circuit 120 is led out from the high temperature side evaporator 121 and then extends upward toward the high temperature side condenser 122 above the Stirling refrigerator 110. The secondary refrigerant pipe 133 of the low temperature side circulation circuit 130 is led out from the low temperature side condenser 131 and then extends downward toward the low temperature side evaporator 132 below the Stirling refrigerator 110. Since the secondary refrigerant pipe 123 from the upper high temperature side evaporator 121 is directed upward and the secondary refrigerant pipe 133 from the lower low temperature condenser 131 is directed downward, the low temperature head 112 is constructed. In addition, the cooling cycle including the low temperature side circulation circuit 130 and the heat dissipation cycle including the high temperature head 111 and the high temperature side first circulation circuit 120 can be separated without excessive or wastefulness. Piping work is also easy.

  If the low-temperature side evaporator 132 is shifted to the side where the Stirling refrigerator 110 is located when viewed from the front, the secondary refrigerant pipe 133 can be more easily routed and the circulation efficiency of the secondary refrigerant is improved. Further, if the connecting portion between the secondary refrigerant pipe 133 and the low-temperature side evaporator 132 is also provided on the side where the Stirling refrigerator 110 is provided, the secondary refrigerant pipe 133 can be routed more easily, and the circulation efficiency of the secondary refrigerant is increased. Is further improved.

  Since the structure in the vicinity of the low-temperature head 112, particularly the piping structure is not complicated, it is easy to form a heat insulating structure so as to surround it. In FIG. 9, the thermal insulator 144 surrounding the low-temperature head 112 and the secondary refrigerant pipe 133 is indicated by phantom lines. The heat insulator 144 can be formed by a method in which a predetermined space is enclosed and urethane foaming is performed therein, or a plurality of foamed urethane blocks are combined.

  The high temperature side condenser 122, the heat radiating fan 124, and the duct 125 are held in the internal space of the machine room 46 by the secondary refrigerant pipe 123 with the Stirling refrigerator 110 itself as a support. For this reason, the high temperature side condenser 122 and the heat radiating fan 124 are supported together with the Stirling refrigerator 110, and the vibration absorbing action of the vibration absorber 143 can be exerted on the high temperature side condenser 122 and the heat radiating fan 124, The vibration level of these components can be reduced at a stroke.

  Further, when attaching the Stirling refrigerator 110 to the support member 140, the Stirling refrigerator 110 connected to the high temperature side first circulation circuit 120 is passed through the opening 141 of the support member 140 from above, and then the low temperature head 112 is connected to the Stirling refrigerator 110. The low temperature side circulation circuit 130 may be connected, and assembly is easy.

  The heat taken out from the high temperature head 111 by the high temperature side first circulation circuit 120 is also used to prevent dew condensation in a dew proof part (a part of the surface of the heat insulating housing 10 where dew condensation is desired). This is realized by the high temperature side second circulation circuit 150. The term “circulation circuit” in the claims refers to the high-temperature side second circulation circuit 150.

  The high temperature side second circulation circuit 150 is thermally connected to the gas phase refrigerant pipe 123G of the high temperature side first circulation circuit 120 via the heat exchanger 151.

  The tertiary refrigerant is sealed in the high temperature side second circulation circuit 150 in a non-depressurized state. The tertiary refrigerant is a mixture of water and antifreeze. Since the tertiary refrigerant needs to have a low viscosity in order to secure the circulation amount, the mixing ratio of the antifreeze liquid is low.

  The piping 152 of the high temperature side second circulation circuit 150 follows the path shown in FIG. 12 after leaving the heat exchanger 151. That is, the pipe 152 becomes the down pipe 152D and descends to the bottom of the heat insulating casing 10, and enters the drain pan 153 installed there. The pipe 152 meanders in the drain pan 153 and raises the temperature of the drain water accumulated in the drain pan 153. A fan 154 is combined with the drain pan 153 to further promote the evaporation of the drain water.

  The pipe 152 exiting the drain pan 153 is divided into two systems at the branching portion 155. One system is the first dew-proof pipe 152F, and the other system is the second dew-proof pipe 152S in parallel therewith. Both the first dew-proof pipe 152F and the second dew-proof pipe 152S enter the lower part of the right side wall of the heat insulating casing 10, pass through the right side wall forward, and reach the lower front part of the heat insulating casing 10. The first dew-proof pipe 152F and the second dew-proof pipe 152S follow different paths therefrom.

  The first dew-proof pipe 152F moves up the front edge of the right side wall of the heat insulating casing 10. Enter the front edge of the horizontal partition 11 in the middle of ascending, draw a hairpin shape, then return to the front edge of the right side wall and continue rising. The first dew-proof pipe 152F reaching the upper end of the right side wall enters the ceiling wall, passes through the front edge of the ceiling wall from right to left, reaches the left side wall, descends the front edge of the left side wall, and further lowers the left side wall. To the rear side and reach the gathering portion 156. Thus, the first dew-proof pipe 152F has the front outer peripheral portion of the heat insulating housing 10 as a main pipe place.

  The second dew-proof pipe 152S enters the bottom wall from the front edge of the right side wall, passes through the front edge of the bottom wall from right to left, and reaches the lower end of the vertical partition 13. The second dew-proof pipe 152S changes its direction upward and passes through the front edges of the vertical partition portions 13 and 12 from the bottom to the top. The second dew-proof pipe 152S that reaches the upper end of the vertical partition 12 is folded back and lowered. In the middle of descending, it enters the front edge of the horizontal partition 11, draws a hairpin shape, and then returns to the front edge of the vertical partition 13. The second dew-proof pipe 152S then enters the front edge of the horizontal partition 14 and draws a hairpin shape, then returns to the front edge of the vertical partition 13 and continues to descend to the bottom wall. The second dew-proof pipe 152S then passes through the front edge of the bottom wall from right to left and enters the left side wall, passes through the lower part of the left side wall to the back side, and reaches the gathering part 156. As described above, the second dew-proof pipe 152S has the partition portions (vertical partition portions 12 and 13 and horizontal partition portions 11 and 14) as main piping locations.

  The first dew proof pipe 152F and the second dew proof pipe 152S have different tube types, and the second dew proof pipe 152S has a flow passage cross-sectional area (a cross-sectional area inside the pipe) of the first dew proof pipe 152F. The cross-sectional area of the channel is larger. In addition, the first dew-proof pipe 152F and the second dew-proof pipe 152S are designed so that their overall lengths are approximately the same. Since the highest part of the second dew prevention pipe 152S reaches the upper end of the vertical partition 12, the first dew prevention pipe 152F and the second dew prevention pipe 152S have the same maximum height.

The pipes 152 unified by the gathering part 156 enter the circulation pump 157 installed at the bottom of the heat insulating housing 10. A positive displacement pump is used as the circulation pump 157, a suction side gas-liquid separator 158 is connected to the suction side, and a discharge side gas-liquid separator 159 is connected to the discharge side.
The suction-side gas / liquid separator 158 and the discharge-side gas / liquid separator 159 separate bubbles from the refrigerant conveyed through the pipe 152. The structure and arrangement of the circulation pump 157, the suction side gas / liquid separator 158, and the discharge side gas / liquid separator 159 will be described in detail later.

  The pipe 152 exiting the circulation pump 157 becomes an upstream pipe 152U and returns to the heat exchanger 151.

  A dew proof portion 160 (see FIG. 8) includes the right and left walls, the ceiling wall and the bottom wall, and the front edges of the horizontal partition and the vertical partition wall. The first dew-proof pipe 152F and the second dew-proof pipe 152S pass near the surface of the heat-insulating housing 10 in the dew-proof part 160, and the temperature obtained from the high-temperature side first circulation circuit 120 via the heat exchanger 151 is the place. To tell. Thereby, the temperature of the dew proof part 160 is maintained above the dew point.

  As described above, the flow passage cross-sectional area of the second dew prevention pipe 152S is larger than that of the first dew prevention pipe 152F. The second dew prevention pipe 152S that passes through the partition exposed to a lower temperature inside the heat insulation casing 10 requires more heat than the first dew prevention pipe 152F that passes through the outer peripheral portion of the heat insulation case 10. However, since the second dew proof pipe 152S has a larger flow passage cross-sectional area than the first dew proof pipe 152F, more refrigerant flows through the second dew proof pipe 152S, and the appropriate heat can be obtained. Allocation can be realized.

  Moreover, as above-mentioned, since the 1st dew prevention pipe | tube 152F and the 2nd dew proof pipe | tube 152S are mutually set to the same extent as the full length and mutual highest height, 2 There is no cause of refrigerant drift between the dew prevention pipes 152S, and in any case, a smooth flow of the refrigerant can be ensured. In addition, the flow rate ratio of the refrigerant is almost determined by the flow path cross-sectional area ratio of the dew-proof pipe, and the piping design is easy.

  In disposing the first dew-proof pipe 152F and the second dew-proof pipe 152S on the back side of the outer shell part of the heat insulating housing 10 and the partition part, an operation of attaching the pipe to the back side of the outer shell part with butyl rubber tape is performed. At this time, the first dew prevention pipe 152F having a small flow path cross-sectional area, that is, a thin outer diameter is difficult to be in close contact with the outer shell portion with a tape. There are few problems because it is a small part. On the other hand, the second dew-proof pipe 152S having a large outer diameter can be brought into close contact with the outer shell portion with a tape, and it is possible to achieve the problem of transmitting more heat to the partition portion where the temperature is lowered.

  Depending on the location, there may be a design in which the dew-proof pipe is pressed against the inner surface of the outer shell portion with a part arranged inside the outer shell portion instead of the butyl rubber tape. If common parts are used for both the first dew-proof pipe 152F and the second dew-proof pipe 152S, the second dew-proof pipe 152S having a large outer diameter is in close contact with the outer shell portion. Although the situation where the first dew-proof pipe 152F having a thin outer diameter does not adhere to the outer shell portion also occurs here, it is not a big problem for the same reason as in the case of the butyl rubber tape.

  Next, the arrangement of the low temperature side evaporator 132 and the cold air passage will be described with reference mainly to FIG. The low temperature side evaporator 132 is placed at a position below the Stirling refrigerator 110 inside the heat insulating casing 10. Furthermore, it is arranged at a level below the lower part of the vertical partition 12. Thereby, the natural circulation of the secondary refrigerant is performed more stably.

  The low temperature side evaporator 132 is disposed in the cold air passage 50 (see FIG. 3) provided in front of the back wall of the fourth partition portion 18. Another cold air passage 51 is provided in front of the cold air passage 50. In the lower part of the cool air passage 50, an intake port 52 for sucking the return air that has finished the role of cooling the storage room is formed. The low temperature side evaporator 132 is installed at a position above the intake port 52 in the cold air passage 50. Above the low-temperature side evaporator 132, a fan 53 that blows air into the cool air passage 51 is provided.

  Three cold air passages serving as branch lines extend from the cold air passage 51. The first one is a cold air passage 54 that sends cold air to the first partition 15 and the second partition 16. The cool air passage 54 rises to the front of the wall at the back of the second partition portion 16, and a discharge damper 55 and a fan 56 are provided there. The cool air passage 54 past the fan 56 enters the vertical partition 12 and rises inside the vertical partition 12 as an ascending cool air passage 54U (see FIG. 3).

  The ascending cool air passage 54U that reaches the upper portion of the vertical partition 12 continues to the descending cool air passage 54D via a short horizontal communication passage 54H. The descending cold air passage 54 </ b> D descends to the lower side of the vertical partition portion 12 and on the front side of the ascending cold air passage 54 </ b> U. The ascending cold air passage 54U, the horizontal communication passage 54H, and the descending cold air passage 54D are inverted in a substantially U shape.

  A plurality of cool air discharge ports 57 for discharging cool air to the second partition portion 16 are formed in the ascending cool air passage 54U at intervals in the vertical direction. A plurality of cold air discharge ports 58 for discharging cold air to the first partition 15 are formed in the descending cold air passage 54D at intervals in the vertical direction. The cool air discharge ports 57 and 58 are located in the vertical partition 12.

  The total opening area of the plurality of cold air discharge ports 57 and the total opening area of the plurality of cold air discharge ports 58 may be distributed according to the volume ratio of the second partition portion 16 and the first partition portion 15. Further, the plurality of cool air discharge ports 57 are arranged in the second partition section 16 and the plurality of cool air discharge ports 58 are arranged in the first partition section 15 so that the room temperature is made uniform. It is desirable to determine the position of the cold air outlet through the experiment.

  The amount of cool air flowing through the upstream cool air passage 54U is the sum of the amount of cool air supplied from the cool air discharge port 57 and the amount of cool air supplied from the cool air discharge port 58. Accordingly, the upstream cool air passage 54U needs a larger cross-sectional area than the downstream cool air passage 54D. It is desirable that the cross-sectional area ratio between the upstream cool air passage 54U and the downstream cold air passage 54D is also determined through experiments.

  Two transverse cold air passages communicate with the cold air passage 54. One is a transverse cold air passage 59 that branches before the cold air passage 54 enters the vertical partition 12, and crawls the wall behind the isolation partition 16 a along the lower surface of the bottom shelf 32. A cool air discharge port 60 is formed in the lateral cool air passage 59 at a location away from the vertical partition 12 by a predetermined distance. A plurality of the cold air discharge ports 60 are formed at intervals in the left-right direction in the isolation section 16a. In the present embodiment, two cold air outlets 60 are provided. The cold air discharge port 60 supplies cold air toward the inside of the case 33. It is preferable that the cool air discharge port 60 has a larger opening area as it is arranged on the downstream side of the lateral cool air passage 59 so that the temperature becomes uniform between the left side portion and the right side portion of the isolation section 16a.

  The other transverse cold air passage is a transverse cold air passage 61 that branches off from the ascending cold air passage 54U, and covers the corner portion formed by the back wall of the second partition 16 and the ceiling. A cool air discharge port 62 is formed in the lateral cool air passage 61 at a location away from the vertical partition 12 by a predetermined distance. A plurality of cold air discharge ports 62 are formed in the second partition part 16 at intervals in the left-right direction. In the present embodiment, two cold air discharge ports 62 are provided. It is preferable that the cold air outlet 62 has a larger opening area as it is arranged on the downstream side of the horizontal cold air passage 61 so that the temperature is made uniform between the left side portion and the right side portion of the second partition portion 16.

  Of the three cold air passages extending from the cold air passage 51 as a branch line, the second one is a cold air passage 63 that sends the cold air to the third partition portion 17. The cool air passage 63 is provided with a discharge damper 64, and a cool air discharge port 65 is formed downstream thereof.

  Of the three cold air passages extending from the cold air passage 51 as a branch line, the third one is a cold air passage 66 for sending cold air to the temperature switching section 19. The cold air passage 66 is provided with a discharge damper 67, a fan 68, a heater 69, and a cold air discharge port 70 from upstream to downstream.

  In the cold air passage 51, not only the cold air passages 54, 63 and 66 but also a cold air discharge port (not shown) for directly discharging the cold air to the fourth partition portion 18 is formed.

  The cold air that has cooled each compartment is returned to the intake port 52 of the cold air passage 50 via the return passage. A return passage 71 is prepared for the second partition 16. The return passage 71 has intake ports at two locations. The first is an air inlet 72 opened to the isolation section 16a. No. 2 is an air inlet 73 opened to the isolation section 16b.

  With respect to the first partition 15, an opening that penetrates the lower rear of the vertical partition 12 and exits to the isolation partition 16 b becomes a return passage 74. The cold air in the first partition portion 15 enters the isolation partition portion 16 b from the return passage 74 and is sucked into the intake port 73.

  A return passage 75 is prepared for the temperature switching section 19. A return damper 76 is provided in the return passage 75.

  A return passage connected to the intake port 52 is also provided for the third partition portion 17, but this is not shown, and only the flow of cold air is shown by a dotted arrow in FIG. 5. The cold air inside the fourth partition 18 is directly sucked into the air inlet 52.

  When the operation of the Stirling refrigerator 110 is continued, the moisture in the air in the heat insulating casing 10 becomes frost and adheres to the low-temperature evaporator 132. The frost reduces the heat exchange efficiency of the low temperature evaporator 132. In order to prevent this, a defrost heater 77 is disposed below the low-temperature side evaporator 132. The defrost heater 77 is energized at an appropriate timing to defrost the low temperature side evaporator 132. Moisture generated by melting frost is dripped as drain water from the funnel portion 78 at the bottom of the cold air passage 50 to the drain pan 153. The drain water is evaporated there by heat from the pipe 152 and wind from the fan 154.

  The control unit 80 shown in FIG. 8 is responsible for overall control of the refrigerator 1. The control unit 80 is based on a temperature setting command or an operation command made through the operation unit 25, and based on a signal from a temperature sensor (not shown) disposed in each unit, the Stirling refrigerator 110, the ice making unit 43, and the fan 53. The discharge damper 55, the fan 56, the discharge damper 64, the discharge damper 67, the fan 68, the heater 69, the return damper 76, the defrost heater 77, the fan 154, the circulation pump 157, and the like are controlled to adjust the temperature of each chamber. Also, make ice and defrost. Note that the electrical components constituting the control unit 80 are housed in an electrical box 81 (see FIGS. 3 and 4) installed on the ceiling of the heat insulating housing 10.

  When the control unit 80 starts operation of the Stirling refrigerator 110, heat is generated in the high temperature head 111. The secondary refrigerant inside the high-temperature side evaporator 121 evaporates and becomes gas due to the warm heat, and the warm heat is held as latent heat. The gasified secondary refrigerant ascends the gas-phase pipe 123G and enters the high-temperature side condenser 122, where it condenses and sensible heat of latent heat. The warm heat that has become sensible heat is dissipated from the surface of the high-temperature side condenser 122 to the outside of the cabinet. The wind blown from the heat dissipation fan 124 helps heat dissipation. The secondary refrigerant that has condensed and turned into a liquid descends the liquid phase pipe 123 </ b> L and returns to the high temperature side evaporator 121.

  Cold heat is generated in the low-temperature head 112. The gaseous secondary refrigerant inside the low temperature side condenser 131 is condensed by the cold and becomes a liquid, and the cold is held as latent heat. The liquefied secondary refrigerant descends the liquid phase pipe 133L and enters the low temperature side evaporator 132, where it evaporates due to the heat in the refrigerator 1. The cold heat becomes sensible heat by the evaporation of the secondary refrigerant. The secondary refrigerant that has evaporated to gas goes up the gas-phase pipe 133G and returns to the low-temperature side condenser 131.

  When the fan 53 is operated in a state in which the cold heat is sensible in the low temperature side evaporator 132, the air sucked from the inlet 52 at the lower end of the cold air passage 50 is cooled by the low temperature side evaporator 132 and becomes cold air. The cool air is sent to the cool air passage 51 by the fan 53 and further sent to the cool air passages 54, 63, 66 from there. Further, it is blown out from the cold air discharge port (not shown) to the fourth partition portion 18.

  The cooling device 100 is cool air having a discharge temperature that is lower than the minus 18 ° C. that is a refrigeration temperature that can be achieved by a normal compressor cooling device, on average minus 42 to 43 ° C., and locally about minus 50 ° C. Temperature is feasible. For this reason, the 4th division part 18 from which the cold air from the fan 53 blows directly can reduce indoor temperature to about minus 40 degreeC. An ice making fan (not shown) in the ice making unit 43 blows this cold air against water to make ice, and ice making proceeds quickly. In addition, by adjusting the refrigerating capacity of the cooling device 100, a cold air temperature of about minus 18 ° C. can be obtained.

  As can be seen from FIG. 12, in the second dew prevention pipe 152S entering the vertical partition part 13, the upstream part is next to the fourth partition part 18 which is the partition part that can be at the lowest temperature. Pass through. For this reason, the part where the amount of heat transport is large in the second dew prevention pipe 152S can be matched with the part that requires a large amount of heat in the partition part to prevent condensation, and the prevention of condensation can be realized rationally.

  The third partition portion 17 can control the amount of cool air flowing in by adjusting the opening degree of the discharge damper 64. For this reason, irrespective of the 4th division part 18, the temperature of the 3rd division part 17 can be maintained to minus 18 degreeC which is a normal freezing temperature.

  The temperature switching section 19 is used in a wide temperature range from the chilled temperature to minus 18 ° C., and the temperature adjustment controls the amount of cold air flowing in by the discharge damper 67 and the return damper 76, and if necessary, the heater This is done by heating the cool air at 69.

  Since the temperature switching section 19 is also used for thawing frozen food, there may be a large temperature difference from the fourth section 18. In order to prevent the high temperature of the temperature switching section 19 from affecting the fourth partition section 18, a portion of the vertical partition 13 between the temperature switching section 19 and the fourth partition section 18 is particularly thick. Has been. Further, the return passage 75 is independent of the fourth partition portion 18 so that the air returning from the temperature switching partition portion 19 to the intake port 52 is not mixed with the air in the fourth partition portion 18.

  When the discharge damper 67 and the return damper 76 are closed and the fan 68 is operated, air circulates in the temperature switching section 19. When the heater 69 is energized in this state, the temperature of the temperature switching section 19 can be increased to a high temperature of 50 to 80 ° C. far exceeding the chilled temperature. Since such a high temperature suppresses the growth of spoilage bacteria, food and others can be stored hygienically in a heat-retaining state.

  Cold air is sent from the fan 56 to the first partition portion 15 and the second partition portion 16 through the cool air passage 54, but the cold air does not overcool the first partition portion 15 and the second partition portion 16. In addition, the amount of cool air is adjusted by the discharge damper 55. The cool air enters the cool air passage 54U from the cool air passage 54, and blows out from the cold air discharge port 57 to the second partition section 16 while rising therethrough. Since a plurality of the cold air discharge ports 57 are formed in the space above the isolation section 16a with a space in the vertical direction, the space is uniformly cooled.

  A part of the cool air enters the transverse cool air passage 61 near the upper end of the ascending cool air passage 54U and blows out from the cool air discharge port 62. Since the cold air discharge port 62 is provided at a predetermined distance from the vertical partition 12, the cold air discharged from the cold air discharge port 57 and the cold air discharged from the cold air discharge port 62 are above the isolation partition 16a. The space is cooled uniformly. Since the two cold air discharge ports 62 are formed at intervals in the horizontal direction, the function of uniform cooling is further enhanced. If the opening area of the cold air discharge port 62 on the downstream side of the lateral cold air passage 61, that is, the right cold air discharge port 62 is made larger than that on the left side, the temperature equalization of the left and right portions of the refrigerator compartment 16 can be further promoted. .

  The cold air that has reached the upper end of the upstream cool air passage 54U enters the downstream cold air passage 54D via the horizontal communication passage 54H. And it blows off to the 1st division part 15 from the cold air discharge port 58, descending | falling in the down cold air | gas channel | path 54D. Since the plurality of cool air discharge ports 58 are formed at intervals in the vertical direction, the first partition 15 is uniformly cooled.

  The cool air indirectly releases cool heat to the left and right compartments as it goes up the ascending cool air passage 54U. In other words, since the heat is received, the temperature of the cold air entering the descending cold air passage 54D is higher than that at the time when it just entered the upstream cold air passage 54U. For this reason, the temperature of the first partition 15 is higher than the temperature of the second partition 16.

  Thus, by providing the cold air passage inside the vertical partition 12, the internal space of the vertical partition 12 that has not been considered so far can be effectively utilized, and the first partition 15 and the second partition 16. The depth of can be expanded. Further, in the vertical partition section 12, an ascending cool air passage 54U that raises the cool air cooled by the low temperature side evaporator 132 and a descending cool air passage 54D that lowers the cool air that has risen above are formed. Since the cool air is supplied to the partition portion 16 from the upstream cool air passage 54U and the cool air is supplied to the first partition portion 15 from the downstream cool air passage 54D, the temperature rise of the cool air that naturally occurs in the flow process is utilized. The temperature can be made different between the partition section 16 and the first partition section 15.

  FIG. 7 shows the detailed structure of the vertical partition 12. The vertical partition 12 includes a vertical partition front portion 12A and a vertical partition rear portion 12B. The vertical partition portion front portion 12A has a structure in which the heat insulator 170 is sandwiched between the left shell 171L and the right shell 171R, and the vertical partition portion rear portion 12B has a structure in which the heat insulator 172 is sandwiched between the left shell 173L and the right shell 173R. is there. The heat insulators 170 and 172 are made by foaming a resin such as styrene or urethane. The left shell 171L, the right shell 171R, the left shell 173L, and the right shell 173R are formed of a resin such as polypropylene or polystyrene. The left shell 171L and the right shell 171R, and the left shell 173L and the right shell 173R are coupled to each other by claw engagement, screwing, and adhesion.

  The front surface of the vertical partition front portion 12A is covered with a cover 174. The cover 174 is made of a color steel plate. Needless to say, this is a magnetic material, and the magnet-containing gaskets attached to the back surfaces of the first heat insulation door 20 and the second heat insulation door 21 are adsorbed exactly. Thereby, the sealing performance of the 1st heat insulation door 20 and the 2nd heat insulation door 21 improves. The cover 174 is connected to the left shell 171L and the right shell 171R by claw engagement, screwing, adhesion, or the like.

  In the vicinity of the back surface of the cover 174, the second dew-proof pipe 152S is arranged. The second dew-proof pipe 152S is disposed in a recess 175 formed in the heat insulator 170. The second dew-proof pipe 152S may be in direct contact with the cover 174, or a butyl rubber sheet may be attached to the back surface of the cover 174, and the cover 174 may be contacted via the butyl rubber sheet. The butyl rubber sheet also reinforces the attachment of the cover 174. In order to bring the second dew-proof pipe 152S into contact with the cover 174, means such as sticking with a butyl rubber tape or pressing with parts arranged inside the left shell 171L and the right shell 171R as described above is used.

  The formation method of the vertical partition 12 described so far is also applied to the formation of the horizontal partitions 11 and 14 and the vertical partition 13.

  In the heat insulating body 172, a concave portion 176 is formed on the side facing the left shell 173L, which is shaped like the rising cool air passage 54U, the horizontal communication passage 54H, and the descending cold air passage 54D. By covering the recess 176 with the left shell 173L, an ascending cool air passage 54U, a horizontal communication passage 54H, and a descending cool air passage 54D are formed.

  Only the left shell 173L separates the upstream cool air passage 54U from the outside. Accordingly, the surface of the left shell 173L is cooled by the cold air passing through the ascending cold air passage 54U, and there is a possibility of condensation, but this portion is in close contact with the right partition 46a of the machine room 46 as seen in FIG. Therefore, condensation is prevented. In addition, if air enters between the left shell 173L and the right partition wall 46a, moisture in the air is condensed. Therefore, a sealing material (for example, butyl rubber, silicon rubber, soft urethane foam, etc.) is used to prevent air from entering this portion. It is good to seal with.

  Condensation occurs on the surface of the left shell 173L when only the left shell 173L is separated from the outside of the horizontal communication passage 54H, which is separated from the right partition 46a and the descending cold air passage 54D. In view of this, a heat insulator 177 is disposed on the back side of the left shell 173L at these locations so that the cold air passing through the horizontal communication passage 54H and the descending cold air passage 54D does not contact the left shell 173L.

  As a result of arranging the heat insulator 177, the descending cold air passage 54D is slightly shifted to the right. Accordingly, the thickness of the heat insulator 172 between the right shell 173R is reduced, but there is less problem because the temperature of the cool air flowing through the descending cool air passage 54D is higher than that of the cool air flowing through the ascending cool air passage 54U.

  The upstream cool air passage 54U is also provided with a heat insulator corresponding to the heat insulator 177 if necessary. For example, this may be the case when a location that deviates from the right partition wall 46a is generated.

  Moreover, when the volume of the 1st partition part 15 is significantly smaller than the volume of the 2nd partition part 16 like this embodiment, the amount of cold air supplied to the 1st partition part 15 is set to the 2nd partition part 16. It can be less than the amount of cold air to be supplied. That is, the cross-sectional area of the descending cold air passage 54D can be made smaller than the cross-sectional area of the ascending cold air passage 54U. In order to reduce the cross-sectional area by compressing the width in the left-right direction of the descending cold air passage 54D in order to make the cross-sectional area of the descending cold air passage 54D smaller than the cross-sectional area of the cold air passage 54U, the space between the right shell 173R and the right shell 173R is reduced. The thickness of the heat insulator 172 can be recovered.

  Moreover, when the volume of the 1st partition part 15 is significantly smaller than the volume of the 2nd partition part 16 like this embodiment, the amount of cold air supplied to the 1st partition part 15 is set to the 2nd partition part 16. It can be less than the amount of cold air to be supplied. That is, the cross-sectional area of the descending cold air passage 54D can be made smaller than the cross-sectional area of the ascending cold air passage 54U. In order to reduce the cross-sectional area by compressing the width in the left-right direction of the descending cold air passage 54D in order to make the cross-sectional area of the descending cold air passage 54D smaller than the cross-sectional area of the cold air passage 54U, the space between the right shell 173R and the right shell 173R is reduced. The thickness of the heat insulator 172 can be recovered.

  A part of the cold air flowing through the cold air passage 54 enters the transverse cold air passage 59 just before entering the upstream cold air passage 54U. The cold air that has entered the transverse cold air passage 59 is blown out into the case 33 from two cold air discharge ports 60 that are arranged at intervals in the horizontal direction, and the inside of the case 33 in the isolation section 16a is uniformly cooled. By adjusting the amount of cold air blown out from the cold air passage 59, the temperature of the isolation compartment 16a is made lower than the space above it, and the isolation compartment as a chilled room or an ice greenhouse, for example, with an internal temperature of 0 ° C. or −3 ° C. 16a can be used. The adjustment of the amount of cold air can be realized by a method such as setting the cross-sectional area of the horizontal cold air passage 59, setting the opening area of the cold air discharge port 60, or installing a damper in the horizontal cold air passage 59.

  Return air from the first partition section 15 and return air from the second partition section 16 having a relatively high temperature flow around the case 34 in the isolation partition section 16b, particularly at the lower side thereof. When the return air from the first partition 15 and the return air from the second partition 16 flow, the temperature drop of the isolation partition 16a is small, for example, the internal temperature becomes a level of 5 ° C. Therefore, the isolation | separation division part 16b can be utilized as a vegetable storage space. Moreover, the partition cover 35 closes the upper surface opening part of the case 34 exactly, and, thereby, the moisture evaporation of the foodstuff in the case 34 is suppressed. Therefore, the inside of the case 34 becomes a space more suitable for vegetable storage.

  The effect that the cooling cycle and the heat dissipation cycle can be separated without difficulty and waste by placing the low temperature portion on the bottom and the high temperature portion on the top can also be enjoyed by a cooling device other than the cooling device. For example, in the case of a cooling device using a Peltier element, the low temperature head 112 and the low temperature side evaporator 132 are replaced with the low temperature part of the Peltier element, and the high temperature head 111 and the high temperature side condenser 122 are replaced with the high temperature part of the Peltier element. The effect of can be obtained.

  The same applies to a refrigeration cycle that uses a refrigerant such as HC refrigerant and that includes a compressor, a condenser, a refrigerant pipe, an expansion valve, a capillary tube, an evaporator, and the like as a cooling device. If a heat generating part such as a compressor or a condenser is placed in the machine room 46 and a part of a capillary tube or an evaporator is placed in the storage, the heat generating part is located on the upper rear surface of the heat insulating housing 10. Can easily escape upward, the influence of heat on the storage chamber is reduced, and a cooler with less energy loss can be obtained.

  In addition, the effect of providing the concave machine room on the upper back surface of the heat insulating housing is not unique to a refrigerator equipped with a Stirling refrigerator. Even in a compressor type cooling device using a refrigerant such as HC refrigerant, the protrusion of the machine room to the storage chamber can be reduced, and a cooler with good volumetric efficiency can be obtained. If a compressor is placed in the machine room and a condenser or refrigerant pipe is provided on a part of the ceiling of the heat insulating housing, the protrusion of the machine room to the storage room is further reduced, and the effective internal volume of the storage room is reduced. Increase.

  Subsequently, the structure and arrangement of the circulation pump 157, the suction-side gas-liquid separator 158, and the discharge-side gas-liquid separator 159 will be described mainly based on FIG. These are accommodated in a sound insulation space 180 (see FIG. 4) formed so that the lower back of the heat insulating housing 10 is recessed toward the storage chamber. The sound insulation space 180 is entirely surrounded by a wall. In the place where the heat insulating wall of the heat insulating casing 10 exists, the heat insulating wall becomes the wall of the sound insulating space 180, and in the place where the heat insulating wall of the heat insulating casing 180 does not exist, the sound insulating panel 181 attached to the heat insulating casing 10 is the sound insulating space. It becomes a wall. In the embodiment, one sound insulation panel 181 constitutes the bottom of the sound insulation space 180, and the circulation pump 157 is installed on the top surface thereof. The circulation pump 157 is installed using a rubber mount or a vibration suspension structure to absorb vibration.

  As described above, the circulation pump 157 is of a positive displacement type, and a piezoelectric pump is used in the embodiment. The circulation pump 157 partitions the internal space of the cylindrical casing 182 with a disk-shaped piezoelectric element 183 to form a pump chamber 184 and a back pressure chamber 185. A suction port 186 and a discharge port 187 are formed in the pump chamber 184. A check valve 188 is provided at the suction port 186, and a check valve 189 is provided at the discharge port 187.

  When an alternating voltage having a predetermined frequency is applied to the piezoelectric elements 183, the piezoelectric elements 183 are alternately bent in the vertical direction in FIG. When the piezoelectric element 183 bends downward in FIG. 13, the inside of the pump chamber 184 becomes negative pressure, and the refrigerant flows into the pump chamber 184 from the suction port 186. Although the negative pressure reaches the discharge port 187, the check valve 189 reacts immediately, so that no refrigerant flows from the discharge port 187. Conversely, when the piezoelectric element 183 bends upward in FIG. 13, the inside of the pump chamber 184 becomes positive pressure, and the refrigerant is pushed out from the discharge port 187. Although the positive pressure reaches the suction port 186, the check valve 188 reacts immediately, so that the refrigerant does not flow backward from the suction port 186. When the piezoelectric elements 183 are repeatedly bent in different directions, the refrigerant is sucked from the suction port 186 and the operation discharged from the discharge port 187 is performed in a pulsating manner.

  Since the circulation pump 157 operates on the above operating principle, when the circulation pump 157 is driven, a pressure fluctuation is generated inside the pipe 152. The pressure fluctuation is periodically generated in accordance with the driving frequency of the circulation pump 157. That is, pressure pulsation occurs. Due to the pulsation of the pressure, the pipe 152 itself generates vibration and accompanying noise, and if it is transmitted to the outer wall of the refrigerator 1 and amplified, the quietness of the refrigerator 1 is significantly reduced, and the commercial value is greatly impaired. It is. In addition, the flow rate of the circulation pump 157 is also reduced because the liquid is intermittently sent and repeated repeatedly and stopped.

  Therefore, the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159 come into play. The gas stored in each of the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159 alleviates pressure pulsation in both the suction-side piping and the discharge-side piping of the circulation pump 157. For this reason, vibrations of the circulation pump 157 and the pipe 152 are reduced, and noise is reduced.

  And since elements that generate vibration and accompanying noise, such as the circulation pump 157 and the piping 152 connected thereto, the suction-side gas-liquid separator 158, and the discharge-side gas-liquid separator 159, are housed in the sound insulation space 180, The noise reduction of the refrigerator 1 can be realized.

  If the internal pressure of the high temperature side second circulation circuit 150 is adjusted to be equal to or higher than the atmospheric pressure at the position of the circulation pump 157, cavitation due to the drive of the circulation pump 157 can be suppressed.

  The piping 152 from the suction side gas-liquid separator 158 to the circulation pump 157 is designed so as not to generate a curved portion or a bent portion that protrudes upward. This is in order to prevent bubbles from being trapped in the curved portion or the bent portion and obstructing the circulation of the refrigerant.

  The suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159 each have the major axis of the container inclined to make the upper side the inlet side and the lower side the outlet side.

  Since the gas-liquid separator is a structure that requires a certain amount of volume and length, if the major axis of the container is arranged vertically, the sound insulation space 180 will bite into the storage chamber of the refrigerator 1 and be stored. The amount of heat insulation layer necessary to separate the chamber from the sound insulation space 180 is also increased. If the major axis of the gas-liquid separator body is inclined as in this configuration, the sound insulation space 180 does not need to be so high, and the sound insulation space bites into the storage room is reduced. Can do. If the major axis direction of the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159 is made to coincide with the left-right direction of the heat-insulating housing 10, the depth dimension of the sound insulation space 180 can be reduced. Intrusion of the sound insulation space can be further reduced.

  And, by inclining the major axes of the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159, the channel cross-sectional area in the gas-liquid separator is increased and the water surface is increased. Can do. For this reason, the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159 can sufficiently perform gas-liquid separation by reducing the flow velocity compared to the main piping portion of the high-temperature side second circulation circuit 150.

  The gas storage spaces of the suction side gas / liquid separator 158 and the discharge side gas / liquid separator 159 are filled with nitrogen gas. Nitrogen gas is safe and inexpensive, and is inert so that it does not corrode the piping 152 and the circulation pump 157 of the high-temperature side second circulation circuit 150. In addition, when the gas is easily dissolved in the water-based refrigerant, the tendency of the gas to dissolve in the refrigerant on the discharge side of the high-pressure circulation pump 157 and to escape from the refrigerant on the suction side of the low-pressure circulation pump 157 becomes prominent. However, there is no concern because nitrogen gas is difficult to dissolve in water-based refrigerant.

  The gas storage capacity of the suction-side gas-liquid separator 158 is a value of an expression expressed by (gas volume at the time of sealing) × {atmospheric pressure ÷ (atmospheric pressure−differential pressure generated in the circulation circuit by the circulation pump)}. It is considered smaller.

  When the circulation pump 157 is operated, the discharge-side gas-liquid separator 159 is pressurized by the differential pressure generated in the high-temperature side second circulation circuit 150 by the circulation pump 157, and the internal gas is compressed to reduce the volume. On the contrary, the suction side gas-liquid separator 158 is depressurized, and the internal gas expands to increase its volume. Further, a phenomenon occurs in which the sealed gas is transferred from the discharge side gas / liquid separator 159 to the suction side gas / liquid separator 158. This is because the gas is dissolved in the refrigerant in the discharge-side gas-liquid separator 159 that becomes high pressure, and the gas escapes from the refrigerant in the suction-side gas-liquid separator 158 that becomes low pressure. When the circulation pump 157 is operated for a long time, most of the gas sealed in the high temperature side second circulation circuit 150 is transferred to the suction side gas-liquid separator 158. If the gas storage capacity of the suction-side gas-liquid separator 158 is too large, the gas in the discharge-side gas-liquid separator 159 is exhausted, and the discharge-side gas-liquid separator 159 has the ability to relieve pressure pulsation. To lose. Therefore, the gas storage capacity of the suction-side gas-liquid separator 158 must be calculated from the volume of all the enclosed gas in the initial state, taking into account the expansion of the enclosed gas due to the pump differential pressure. The condition is satisfied by making the gas storage capacity of the suction side gas-liquid separator 158 smaller than the value of the above formula.

  In the present invention, a commercial refrigerator is assumed as the refrigerator 1, and the circulation pump 157 does not require a particularly powerful capability. Therefore, the term of (atmospheric pressure-differential pressure generated in the circulation circuit by the circulation pump) in the above formula is always positive.

  The liquid level in the suction-side gas-liquid separator 158 when the circulation pump 157 is operated finally becomes the vicinity of the gas-liquid separation boundary, in other words, the upper end height of the outlet 158a of the suction-side gas-liquid separator 158. Stable in the vicinity. In this state, the gas in the suction-side gas-liquid separator 158 may flow out from the outlet, that is, overflow, but the amount of overflow is small and the circulation pump 157 temporarily sucks the bubbles. Is immediately discharged and trapped in the discharge-side gas-liquid separator 159. For this reason, the circulation system is immediately stabilized.

  The amount of internal gas in the suction-side gas-liquid separator 158 and the amount of internal gas in the discharge-side gas-liquid separator 159 is such that the sum of the volumes is volume expansion when all the refrigerant in the high-temperature side second circulation circuit 150 is frozen. It is set to exceed the minute. As a result, even if a cold climate is hit and all the refrigerant in the high-temperature side second circulation circuit 150 is frozen, the volume expansion is equal to the internal gas of the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159. Therefore, the pipe 152 can be prevented from bursting.

  Antifreeze components (alcohol, glycol, etc.) are added to the water-based refrigerant so that it is difficult to freeze. However, when the concentration of the antifreeze component increases, the viscosity of the refrigerant also increases and the circulation flow rate of the refrigerant decreases. Therefore, the amount of the antifreeze component must be slightly reduced, and freezing cannot be completely prevented.

  The refrigerant to which the antifreeze component is added freezes in a slurry state and exhibits fluidity. Although it has fluidity, the frozen refrigerant remains in the way of the movement of the check valves 188 and 189 of the circulation pump 157.

  The refrigerant is disclosed to be frozen by ice nuclei accidentally generated from an unstable supercooled state. Therefore, the location where freezing starts and the number of locations cannot be controlled at all. If freezing has progressed in the vicinity of the circulation pump 157, the slurry-like flow stagnates at the check valves 188 and 189, and in the pump, the piezoelectric element 183 bends more than the allowable limit due to the volume expansion of the refrigerant. There is a risk of damage. However, in the configuration of the present invention, the internal gas of the suction-side gas-liquid separator 158 and the internal gas of the discharge-side gas-liquid separator 159 are compressed so that the refrigerant is pushed back to both the suction port 186 and the discharge port 187 of the circulation pump 157. Therefore, it is not necessary to damage the piezoelectric element 183.

  The charging unit that encloses the gas in the high temperature side second circulation circuit 150 is provided in a section from the circulation pump 157 to the discharge side gas-liquid separator 159. In the embodiment, the discharge side gas-liquid separator 159 is provided with a charge pipe 191.

  In the configuration in which the suction-side gas-liquid separator 158 is provided on the suction side of the circulation pump 157 and the discharge-side gas-liquid separator 159 is provided on the discharge side, it is necessary to store gas in both gas-liquid separators. If a charging unit is provided in the section from the circulation pump 157 to the discharge side gas-liquid separator 159, when the gas is charged while the circulation pump 157 is operated, the gas is first stored in the gas storage space of the discharge side gas-liquid separator 159. Go meet. The gas filling the gas storage space of the discharge side gas-liquid separator 159 overflows and then flows through the high-temperature side second circulation circuit 150 to the suction-side gas-liquid separator 158 where it is trapped. If the amount of gas to be charged is appropriate, the gas will not overflow from the suction side gas-liquid separator 158.

  The charge pipe 191 is also used for enclosing the refrigerant. First, air in the high-temperature side second circulation circuit 150 is evacuated by a vacuum pump, and then a predetermined amount of refrigerant is sealed. Taking into account the leakage of the refrigerant accompanying long-term use and the variation in the amount to be filled, it is preferable to enclose a little more than the predetermined amount (for example, 5%).

  The volume of the suction side gas / liquid separator 158 and the discharge side gas / liquid separator 159 is designed in consideration of the amount of refrigerant enclosed. The refrigerant expands in volume by 2 to 3% when the temperature is raised from room temperature to 60 to 70 ° C. The enclosed gas is compressed by this, and also the temperature of the gas itself increases, so that the internal pressures of the suction-side gas-liquid separator 158 and the discharge-side gas-liquid separator 159 rise. It is also necessary to consider the increase in internal pressure when the volume expansion when the refrigerant is completely frozen is absorbed by the compression of the enclosed gas. When the circulation pump 157 is started, the discharge side gas-liquid separator 159 is further pressurized. In consideration of these conditions, the suction-side gas-liquid separator is designed to prevent an increase in internal pressure that adversely affects the performance of the circulation system (refrigerant flow rate, quietness) and reliability (no refrigerant leakage). 158 and the volume of the discharge side gas-liquid separator 159 are designed.

  Inside the suction-side gas-liquid separator 158, a filter 192 that collects foreign matters in the refrigerant is provided. The filter 192 is a mesh filter, has a convex shape toward the outlet 158a of the suction side gas-liquid separator 158, and secures a filtration area.

  In the high-temperature side second circulation circuit 150, in addition to dust and material cutting powder that have entered in the manufacturing stage, oxide scale generated on the inner wall of the pipe 152 over time, and antifreeze with low purity are mixed in the refrigerant. There are various solid foreign substances such as impurities and additives that precipitate like ice at low temperatures. When these foreign substances are sucked into the circulation pump 157, the foreign substances are caught in the check valves 188 and 189, and the liquid feeding capability is reduced. In order to prevent this, it is preferable to provide a filter as close as possible to the suction side of the circulation pump 157. The suction side gas-liquid separator 158 just satisfies this condition. Further, since the suction-side gas-liquid separator 158 has an inner diameter larger than that of a normal pipe portion, a filter 192 having a large filtration area can be installed, and the flow path resistance does not need to be increased so much.

  The cold air discharge port formed in the horizontal cold air passage 61 can have a different shape from the cold air discharge port 62 of FIG. The deformation mode is shown in FIGS. FIG. 15 is a vertical sectional view of the refrigerator, and FIG. 16 is an explanatory diagram of the structure of the cold air passage.

  15 and 16, the horizontal cold air passage 61 is provided with a slit-like cold air discharge port 62A that is long in the horizontal direction. The cold air discharge port 62A is open at a corner portion formed by the back wall of the second partition portion 16 and the ceiling. Since the cold air is discharged from the wide cold air discharge port 62A in this way, the space above the isolation section 16a is uniformly cooled.

  The configuration of the vertical partition 12 can be changed from FIG. The modification is shown in FIG. FIG. 17 is a horizontal sectional view of the refrigerator.

  In the modified embodiment of FIG. 17, the descending cold air passage 54D is moved to the front side. In this way, the heat insulation layer between the front surface of the vertical partition 12 and the cold air passage 54D is thinned, but the temperature of the cold air flowing through the cold air passage 54D is relatively high. The front surface of the portion 12 is unlikely to be excessively cooled. By moving the descending cold air passage 54D in this way, the interval between the ascending cold air passage 54U and the descending cold air passage 54D is widened, so that the width in the front-rear direction of each of the ascending cold air passage 54U and the descending cold air passage 54D is increased. Resistance can be reduced.

  As can be seen in FIG. 17, it is also possible to reduce the thickness of the vertical partition 12 between the ascending cool air passage 54U and the descending cool air passage 54D to form a recess 178, thereby increasing the volume of the storage chamber. The concave portion 178 serves as a communication path between the upper and lower spaces of the shelf 32, and causes cold air circulation in the second partition portion 16, which helps to make the temperature of the second partition portion 16 uniform.

  At the lowermost shelf 32a separating the second partition 16 and the isolation partition 16a and the partition cover 35 separating the isolation partition 16a and the isolation partition 16b, the recess 178 is closed. This prevents cold air from mixing between the second partition portion 16 and the isolation partition portion 16a, and prevents cold air from mixing between the isolation partition portion 16a and the isolation partition portion 16b. Prevent the set temperature difference from disappearing. Closing the recess 178 can be realized by a means such as providing a rib or inserting a heat insulating material therein. It is good also as not providing the recessed part 178 at all with respect to the isolation | separation division part 16a, 16b.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

    The present invention can be widely used in a refrigerator for home use or business use.

Front view of refrigerator Front view of the refrigerator with the insulated door removed Vertical section of the refrigerator Vertical sectional view of the refrigerator in different parts Configuration diagram of cold air passage Horizontal sectional view of the refrigerator cut along line AA in FIG. Expanded horizontal cross section of vertical partition Schematic configuration diagram of the cooling device mounted in the refrigerator Partial vertical cross-sectional view of the Stirling refrigerator installed part of the refrigerator Top view of Stirling refrigerator supported by support member Top view of support member Schematic perspective view of cooling device Sectional view showing the structure of the circulation pump and gas-liquid separator Block diagram showing the flow of cold air Vertical sectional view of the refrigerator showing the deformation mode of the cold air outlet Configuration explanatory diagram of the cold air passage showing the deformation mode of the cold air discharge port Horizontal sectional view of the refrigerator showing the deformation mode of the vertical partition

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerator 10 Heat insulation housing | casing 11,14 Horizontal direction partition part 12,13 Vertical direction partition part 15 1st partition part 16 2nd partition part 17 3rd partition part 18 4th partition part 19 Temperature switching partition part 20, 21, 22 23, 24 Thermal insulation door 46 Machine room 50, 51, 54, 63, 66 Cold air passage 54U Up cold air passage 54D Down cold air passage 59, 61 Lateral cold air passage 57, 58, 60, 62, 62A, 65, 70 Outlet 100 Cooling device 110 Stirling refrigerator 111 High temperature head 112 Low temperature head 120 High temperature side first circulation circuit 121 High temperature side evaporator 122 High temperature side condenser 123 Secondary refrigerant piping 124 Heat dissipation fan 125 Duct 130 Low temperature side circulation circuit 131 Low temperature side condensation 132 Low temperature evaporator (cooling section)
133 Secondary refrigerant pipe 150 High temperature side second circulation circuit 151 Heat exchanger 152F First dew prevention pipe 152S Second dew prevention pipe 157 Circulation pump 158 Suction side gas / liquid separator 159 Discharge side gas / liquid separator 160 Dew prevention part 180 Sound insulation space 191 Charge pipe 192 Filter

Claims (8)

In the refrigerator that cools the interior of the refrigerator with the cooling unit of the refrigeration apparatus and transmits the waste heat radiated by the refrigeration apparatus to a predetermined place in the circulation circuit,
The circulation circuit circulates a refrigerant with a positive displacement circulation pump, wherein a suction side gas-liquid separator is provided on the suction side of the circulation pump, and a discharge side gas-liquid separator is provided on the discharge side. And a refrigerator. 2. The suction-side gas-liquid separator and the discharge-side gas-liquid separator are each characterized in that the major axis of the container is inclined so that the upper side is the inlet side and the lower side is the outlet side. The listed refrigerator. The refrigerator according to claim 2, wherein the gas storage space of the gas-liquid separator is filled with nitrogen gas. The gas storage capacity of the suction side gas-liquid separator is
(Gas volume at the time of sealing) × {Atmospheric pressure ÷ (Atmospheric pressure−Differential pressure generated in the circulation circuit by the circulation pump)}
The refrigerator according to claim 1, wherein the value is smaller than the value of the expression expressed by the following. The total volume of the internal gas of the suction-side gas-liquid separator and the internal gas of the discharge-side gas-liquid separator exceeds the volume expansion at the time of total freezing of the refrigerant in the circulation circuit. The listed refrigerator. The refrigerator according to claim 1, wherein a charging unit that encloses gas in the circulation circuit is provided in a section from the circulation pump to the discharge-side gas-liquid separator. The refrigerator according to claim 1, wherein a filter for collecting foreign matter in the refrigerant is provided in the suction side gas-liquid separator. The cooler according to claim 1, wherein a sound insulation space for accommodating the circulation pump, the suction side gas-liquid separator, and the discharge side gas-liquid separator is formed.

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