JP2005201532A - Freezing-refrigerating unit and refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a freezing-refrigerating unit and a refrigerator using the freezing-refrigerating unit capable of ensuring high safety while using an inflammable refrigerant with a low global warming potential and avoiding to the utmost such a failure as to cause a sudden stop of cooling by detecting a leakage of the refrigerant to cope with the prevention of the leakage before air flows in to increase the load of a compressor even when piping is damaged on the low pressure side of a connection part or the like of an evaporator. <P>SOLUTION: The refrigerant whose pressure becomes negative in cooling is used, and a condensation temperature sensor 31 disposed in the condensation starting position of a condenser 20, and an evaporation temperature sensor, are provided. When the condensation temperature is not lower than a predetermined temperature in the evaporation temperature, the leakage of the refrigerant is determined, and control is performed to maintain a state of preventing the leakage of the refrigerant and the inflow of air by suppressing the rotating speed of the compressor 19. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a refrigeration unit in which a compressor and a condenser of a cooling system are installed at the upper part of the gantry and an evaporator is installed in the lower part of the gantry, and a large commercial refrigerator / freezer having the refrigeration unit at the upper part of the main body. It is.

  Conventionally, in a commercial large-sized refrigerator-freezer exceeding 500 L, a refrigerator-freezer unit using a high-capacity compressor of 300 W or more is used. In particular, in the system for cooling the freezer compartment, a low boiling point refrigerant such as R22 or R404A that can provide a high refrigerating capacity even when the evaporation temperature is low is used.

  However, in recent years, from the viewpoint of preventing global warming, it has been desired to switch from chlorofluorocarbon refrigerants such as R22 and R404A, which have a high warming potential, to natural refrigerants such as R290 and R600a, and to reduce carbon dioxide emissions. For large-sized freezer refrigerators for business use with a large amount of electric power, it is desired to save energy as soon as possible.

  Here, commercial large-sized refrigerator-freezers have a large amount of refrigerant enclosed, and because there is a lot of fire as an ignition source in the surrounding kitchen environment, careful consideration is being given to the application of flammable natural refrigerants. . In home refrigerators, a technique for detecting leakage when refrigerant piping is damaged and flammable natural refrigerant leaks has been studied (for example, see Patent Document 1).

  Hereinafter, the conventional refrigerator will be described with reference to the drawings.

  FIG. 4 is a cross-sectional view of a conventional refrigerator described in Patent Document 1.

  As shown in FIG. 4, it is composed of a freezer compartment 1, a door 2, and a cabinet 3. In the upper part of the cabinet 3, a unit base 5 for fixing the freezing / refrigeration unit 4 and a cooling room 6 for cooling the freezing room 1 are installed.

  The refrigeration unit 4 includes a compressor 7 having a reciprocating type compression mechanism, a condenser 8, a capillary 9 as a decompression means, an evaporator 10, a suction pipe 11 of the compressor 7, a condensing fan 12, and an evaporating fan 13. Become. A drain 14 for discharging the defrost water in the cooling chamber 6 is embedded in the back surface of the cabinet 3.

  Further, a radiant heater 15 attached to the lower part of the evaporator 10, an evaporation temperature sensor 16 attached to a refrigerant pipe (not shown) of the evaporator 10, and an outlet temperature sensor 17 attached to the upper part of the evaporator 10. And the indoor temperature sensor 18 attached to the upper part of the freezer compartment 1 is installed.

  Next, the operation of the refrigeration unit 4 will be described. R600a which is a low boiling point refrigerant is used as the refrigerant. The refrigerant R <b> 600 a is compressed by the compressor 7, condensed by the condenser 8, depressurized by the capillary 9, and sent to the evaporator 10. Then, after being evaporated by the evaporator 10, it is refluxed to the compressor 7 through the suction pipe 11. At this time, the capillary 9 and the suction pipe 11 are subjected to heat exchange, and the cold and waste heat of the refrigerant returning to the compressor 7 is recovered.

  At this time, the condensation temperature of the refrigerant R600a is about 40 ° C. (about 5.3 atm) during normal operation at an ambient temperature of 30 ° C. and an indicated value of the indoor temperature sensor 18 of the freezer compartment 1 (hereinafter referred to as the room temperature) −20 ° C. The evaporation temperature is about −30 ° C. (about 0.5 atm).

  Then, the elapsed time after activation or defrosting is integrated, and whenever the integrated time exceeds about 10 hours, the compressor 7 is stopped and the radiant heater 15 is energized to defrost the evaporator 10. At this time, when the outlet temperature sensor 17 detects about 5 ° C., it is determined that the defrosting is completed, and energization of the radiant heater 15 is stopped.

  Further, when the difference between the indication values of the evaporation temperature sensor 16 and the outlet temperature sensor 17 becomes larger than 5 ° C., for example, at the indoor temperature −20 ° C. and the indication value −30 ° C. of the evaporation temperature sensor 16, When the indicated value is higher than −25 ° C., it is determined that the refrigerant has leaked, and the compressor 7 is stopped, and the fact that the refrigerant has leaked is notified.

  When the refrigerant leaks to the outside, the cooling capacity is reduced and the cooling tendency tends to be slow. At the outlet of the evaporator 10, the refrigerant is completely vaporized, and the temperature rises to near the temperature of the indoor air flowing into the evaporator 10 as superheated steam. To do. That is, when refrigerant leakage is detected based on the difference between the indicated values of the evaporation temperature sensor 16 and the outlet temperature sensor 17 being greater than a predetermined value of 5 ° C., the refrigerant is detected at a relatively early stage where a slow cooling tendency occurs. It is possible to notify that a leak has occurred.

As a result, the user can confirm the leakage of the refrigerant, stop using the fire, or make a service call so that it can be dealt with early and safety can be improved.
JP-A-9-14811

  However, the above conventional refrigerator detects refrigerant leakage on the premise that the cooling capacity is reduced and the refrigerant becomes superheated steam at the outlet of the evaporator 10, but in a commercial large refrigerator, Since the frequency of door opening and closing is high, if refrigerant leakage occurs during use, the evaporation capacity of the evaporator 10 is reduced due to frost formation, causing a problem that the refrigerant hardly becomes superheated steam at the outlet of the evaporator 10.

  Further, since the conventional refrigerator uses R600a which is a high boiling point refrigerant, the low pressure is lower than the atmospheric pressure, and if the pipe is damaged at the connection part of the evaporator 10, the air is not leaked before the refrigerant leaks. Flows in, the high pressure rises and the cooling capacity decreases, and in the worst case, an overload occurs due to air compression, and the compressor 7 stops and does not restart and may become uncooled. .

  That is, when R600a, which is a high boiling point refrigerant, is used, if the pipe is damaged on the low pressure side such as the connection part of the evaporator 10, the compressor 7 is stopped due to air compression and cannot be restarted, and the refrigerant is discharged from the damaged part of the pipe However, the refrigerant leakage cannot be detected only by using the difference between the indication values of the evaporation temperature sensor 16 and the outlet temperature sensor 17 as a reference. Therefore, when R600a which is a high boiling point refrigerant is used, a measure for determining that the refrigerant has leaked when the overload of the compressor 7 continues or when the start and stop are repeated due to the overload has been proposed.

  On the other hand, a large commercial refrigerator is required to have a higher cooling capacity and a higher load than a household refrigerator, and to continue a minimum cooling operation even when a failure occurs. That is, it is necessary to avoid as much as possible a failure in which overload occurs due to air compression and the compressor 7 stops and does not restart and suddenly becomes uncooled.

  Here, a compression ratio, a high pressure pressure, a low pressure pressure at a condensing temperature of 40 ° C., an evaporating temperature of −30 ° C., a supercooling of 0 ° C., and an intake gas temperature of 32 ° C., which are general operating conditions of an ambient temperature of 30 ° C. Table 1 shows the results of comparing the relative values of theoretical efficiency and volume capacity with R600a, which is a high boiling point refrigerant, and other refrigerants.

  As shown in Table 1, R22, R290, and R404A, which are low-boiling refrigerants compared to the high-boiling refrigerants R134a and R600a, have low theoretical efficiency, but have a low compression ratio and high volume capacity, and an evaporation pressure. It can be seen that it is higher than atmospheric pressure. That is, R22, R290, and R404A, which are low-boiling refrigerants, do not cause air compression immediately when the piping is damaged on the low-pressure side such as the connection portion of the evaporator 10, but air compression does not occur. There is a possibility that the evaporating temperature is lowered and air flows in after a large amount of refrigerant leaks during defrosting of the vessel 10.

  Therefore, in large refrigerators for business use, R22, R290, and R404A, which are low boiling point refrigerants, are used, and early detection and notification of refrigerant leaks and suppression of refrigerant leaks can also be used. It is expected to continue the minimum cooling operation.

  The present invention solves the above-described conventional problems, and even when a pipe is damaged on the low pressure side such as a connection portion of an evaporator, an overload occurs due to air compression, and the compressor stops and does not restart. It is an object of the present invention to provide a freezer / refrigeration unit and a refrigerator that avoid a failure that suddenly becomes uncooled as much as possible.

  In order to solve the above conventional problems, the refrigeration unit and the refrigerator of the present invention include a refrigerant whose evaporating pressure during cooling operation is a negative pressure, a compressor with a variable rotation speed, a condenser, a throttling device, and an evaporation device. A compressor, an external fan, and an internal fan, and when the refrigerant leaks from the evaporator or the low-pressure side pipe, the refrigerant leakage detecting means and the rotational speed of the variable speed compressor are suppressed. A refrigerant leakage prevention control means is provided.

  As a result, even if the piping is damaged on the low pressure side such as the connection part of the evaporator during the cooling operation, before the compressor stops due to the flow of air and the compressor load increases, the rotation speed of the compressor It is possible to operate in a state where the evaporation temperature at which the refrigerant hardly leaks to the inside of the cabinet and the air hardly flows in is balanced with the atmospheric pressure.

  The refrigeration unit and refrigerator of the present invention detect refrigerant leakage before the flow of air increases and the compressor load increases even when the piping is damaged on the low pressure side such as the evaporator connection during cooling. As a result, it is possible to maintain a state in which refrigerant leakage and air inflow are unlikely to occur. Therefore, it is possible to prevent failures that cause sudden cooling without causing an overload due to air compression and stopping and restarting the compressor. While avoiding this, high safety can be secured while using a flammable refrigerant with a low global warming potential.

  The invention according to claim 1 of the present invention is a refrigerant in which the evaporating pressure during the cooling operation is negative, a compressor having a variable rotation speed, a condenser, a throttling device, an evaporator, an external fan, and an interior A fan, and means for detecting refrigerant leakage when piping is damaged on the low pressure side such as a connection part of the evaporator and refrigerant leakage prevention control means for suppressing the rotation speed of the variable speed compressor Therefore, even if the piping is damaged on the low-pressure side such as the evaporator connection during cooling, the operation is maintained in a state in which refrigerant leakage and air inflow are unlikely to occur. It is possible to prevent the refrigerant from leaking to the inner side without causing a load to be generated and the compressor to stop and restart.

  According to a second aspect of the present invention, in addition to the first aspect of the invention, the apparatus further comprises a condensing temperature detecting means for detecting the condensing temperature and an evaporating temperature detecting means for detecting the evaporating temperature, which is detected by the condensing temperature detecting means. When the condensation temperature is higher than the temperature set in advance by the evaporation temperature detected by the evaporation temperature detecting means, the refrigerant leakage prevention control is provided that determines that the refrigerant leaks and suppresses the rotation speed of the variable speed compressor. Thus, it is possible to accurately detect an overload state of the compressor due to air inflow and respond by suppressing the rotation speed of the compressor, thereby avoiding a state where the compressor is suddenly stopped due to an overload and is not restarted. .

  The invention described in claim 3 is the same as that of the invention described in claim 1, but further includes a condensation temperature detection means for detecting the condensation temperature, an evaporation temperature detection means for detecting the evaporation temperature, and an internal temperature setting for setting the internal temperature. Means for determining that the refrigerant has leaked when the condensation temperature detected by the condensation temperature detection means is higher than the temperature preset by the evaporation temperature detected by the evaporation temperature detection means. Thus, by raising the set temperature in the chamber to a preset temperature, it is possible to maintain a state where the evaporation pressure and the atmospheric pressure are balanced, in which the leakage of the refrigerant and the inflow of air hardly occur.

  According to a fourth aspect of the present invention, in addition to any one of the first to third aspects of the present invention, a condensing temperature detecting means is provided at the condensing start position of the condenser, whereby a low pressure side such as a connection portion of the evaporator is provided. Therefore, it is possible to accurately detect a state in which the piping is damaged and the air flows in due to damage and the condensation pressure increases.

  According to a fifth aspect of the present invention, in addition to any one of the first to fourth aspects of the present invention, by performing refrigerant leakage prevention control that continuously operates the compressor at a specified rotational speed, an excess at the time of changing the rotational speed is achieved. It is possible to prevent the refrigerant from leaking to the inside of the warehouse during the sudden stop of the compressor due to the load and the defrosting operation.

  The invention according to claim 6 is the warehouse during the defrosting operation by performing the refrigerant leakage prevention control that extends the defrosting operation cycle more than the normal control in addition to any of the inventions of the first to fifth aspects. By suppressing the refrigerant leakage to the inside as much as possible and appropriately performing the defrosting operation, it is possible to suppress a decrease in the evaporation temperature due to the frosting of the evaporator, and to prevent air inflow during the cooling operation.

  The invention according to claim 7 is the control means for warning the user and the means for warning when the operation time of the refrigerant leakage prevention control continues for a specified time or more in addition to any of the inventions of claims 1 to 6. By installing the, the user can confirm the leakage of the refrigerant, stop using the fire, or take a service call to respond early, avoiding the failure that suddenly becomes cold as much as possible And high safety can be ensured.

  According to an eighth aspect of the present invention, in addition to any one of the first to seventh aspects of the present invention, when the condensation temperature is in a normal state, the condenser leak prevention control is automatically returned to the normal control to automatically return the condenser. Even if it is erroneously detected in a state where there is no refrigerant leakage such as an increase in the condensation temperature due to clogging, the user can be kept from worrying more than necessary.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a refrigeration cycle diagram of a refrigerator according to the present embodiment. FIG. 2A is a diagram illustrating the relationship between the internal temperature and time of the refrigerator according to the embodiment, and FIG. 2B is a diagram illustrating the rotational speed control of the compressor, condenser fan, and evaporator fan of the refrigerator according to the embodiment. is there.

  As shown in FIG. 1, the refrigerating cycle of the refrigerator according to the embodiment of the present invention includes R600a (not shown) used as a refrigerant, a compressor 19, a condenser 20, an evaporator 21, a capillary tube 22, Condenser fan 23, evaporator fan 24, refrigerator controller 25, compressor control means 26 as internal control thereof, condenser clogging and operation abnormality alarm sending means 27, defrost control means 28, internal fan control Means 29, external fan control means 30, condensation temperature sensor 31 which is a condensation temperature detection means attached to the inlet pipe of the condenser, evaporation temperature sensor 32 which is an evaporation temperature detection means attached to the inlet pipe of the evaporator, The inside temperature sensor 33 which is the inside temperature detecting means attached to the evaporator fan suction side, the outside air temperature sensor 34 which is the outside temperature detecting means, and the inside temperature It is comprised from the internal temperature setting means 35 which sets to arbitrary temperature.

  A compressor 20, an evaporator 21, and a capillary tube 22 are connected in a closed loop shape with a refrigerant pipe to the variable speed compressor 19, and further a condenser fan 23 with a variable speed is attached to the condenser 20. The evaporator 21 is also provided with an evaporator fan 24 having a variable rotational speed. The evaporator 21 is installed in a refrigerator or the like, and cools the interior. These are controlled by the controller 25.

  Operations of the compressor 19, the condenser fan 23, and the evaporator fan 24 configured as described above will be described with reference to FIG.

  In FIG. 2A, the vertical axis indicates the temperature inside the refrigerator or the like, and the horizontal axis indicates the passage of time. The OFF temperature (t1) and the ON temperature (t2) in FIG. 2A are determined by the internal set temperature set by the internal temperature setting means 35. In this refrigeration apparatus, when the inside of the refrigerator is cooled after the cooling operation is started and the inside temperature reaches t1, the cooling operation is stopped. When this state continues and the inside temperature rises and reaches t2, the cooling operation is performed. Is started. Usually, this is repeated and the internal temperature is maintained at a set temperature having a substantially constant width.

  The operating state of the refrigeration apparatus according to the embodiment of the present invention is divided into three operating states: a section T1 from the initial pull-down to t1, a section T2 from t1 to t2, and a section T3 from t2 to t1.

FIG. 2B shows the rotational speed control of the compressor 19, the condenser fan 23 and the evaporator fan 24. The compressor 19 starts when the temperature of the internal sensor is higher than the ON temperature, and stops when the temperature is lower than the OFF temperature. The number of rotations of the compressor 19 in the section T3 from the ON temperature to the OFF temperature includes the internal set temperature set by the internal temperature setting means 35, the outside air temperature detected by the outside air temperature sensor 34, and the inside temperature. It is controlled as follows according to the internal temperature detected by the sensor.
When the internal temperature sensor is higher than the specified temperature with respect to t2, the rotational speed of the compressor 19 is increased. Conversely, if the internal temperature sensor is lower than the specified temperature with respect to t2, it decelerates. In this case, the upper limit value and the lower limit value of the rotation speed of the compressor 19 are determined by the temperature of the outside air temperature sensor. For example, the upper limit value of the rotational speed is set to a large value at high outside air temperature, and the cooling capacity at the time of overload can be fully demonstrated.On the contrary, the lower limit value of the rotational speed is set to be small at low outside air temperature, Cooling operation suitable for the environment can be performed.

  The rotation speed of the condenser fan 23 and the evaporator fan 24 is switched by the outside fan control means 34 and the inside fan control means 33. The switching timing is basically linked to the upper and lower rotation speeds of the compressor 19. For example, when the compressor 19 speeds up, the rotation speeds of the condenser fan 23 and the evaporator fan 24 are increased by one rank. When the compressor 19 decelerates, the rotation speeds of the condenser fan 23 and the evaporator fan 24 are switched down one rank. However, when the compressor 19 is within the low speed rotation range (for example, the compressor rotation speed: 35 rps or less), the rotation speed of the condenser fan 23 and the evaporator fan 24 is not switched to a higher rank even if the compressor 19 speeds up. . This is because the refrigeration capacity is not so required in the low-speed rotation range, and the fan input is reduced without increasing the fan rotation speed.

  Further, in order to reduce frost formation in the refrigerator, the evaporator fan 24 is operated at a low speed even when the compressor 19 is stopped.

  FIG. 3 shows the usage standards of the compressor 19 according to the embodiment of the present invention. The horizontal axis of FIG. 3 shows the evaporation temperature in the refrigeration cycle, and the vertical axis shows the condensation temperature in the refrigeration cycle. The range where there is no diagonal line is the range of use of the compressor 19. The evaporation temperature is −40 ° C. or more and −5 ° C. or less, and the condensation temperature is 0 ° C. or more and 60 ° C. or less. Furthermore, the condensation temperature has an upper use limit at a given evaporation temperature, which is limited by a compression ratio that is the condensation pressure divided by the evaporation pressure. In the compressor 19 according to the embodiment of the present invention, the compression ratio is 12.5 or less.

  In the refrigerator configured as described above, the behavior of the cooling system when the refrigerant leakage prevention control is not performed when the piping is damaged on the low pressure side such as the connection portion of the evaporator during the cooling operation will be described below. To do.

  When damage or the like occurs in the low-pressure side pipe such as an evaporator during the cooling operation, the high-pressure refrigerant is used in the refrigeration cycle, so the low-pressure side becomes negative pressure and air is sucked from the damaged part of the pipe. The sucked air is compressed by the compressor 19 and flows into the condenser. In the condenser, the refrigerant condenses and causes a phase change, but air does not cause a phase change, so the condensation pressure becomes larger than usual. Furthermore, when air is sent from the low pressure side through the compressor into the condenser, the capillary tube 32 is used in the decompression device in the present embodiment, so the air stays without circulating to the evaporator side. The pressure in the condenser 20 rises abnormally.

  As a result, the high / low pressure of the refrigeration cycle becomes too large, and the compressor 19 becomes overloaded and stops suddenly. In starting after a sudden stop, the balance pressure is high, so the starting torque is insufficient and the compressor does not start. In the state where the compressor does not start, the evaporator side does not become negative pressure, so the refrigerant gradually leaks to the inside of the warehouse. As a result of the gradual leakage of the refrigerant, the balance pressure decreases and the compressor can be started and restarted. However, after start-up, air is sucked in from the low pressure side, which is negative pressure, and the condensation pressure rises as in the previous case, resulting in an overload condition and a sudden stop.

  As described above, when the refrigerant leakage prevention control is not performed and the piping is damaged on the low pressure side, the refrigerant gradually leaks while repeating the cycle of starting and stopping the compressor, Refrigerant stays.

  FIG. 4 shows a flowchart of refrigerant leakage prevention control according to the embodiment of the present invention, and the control will be described below.

  Starting from when the power is turned on, the temperatures of the condensation temperature sensor 31 and the evaporation temperature sensor 32 are read. If the condensation temperature is equal to or higher than a predetermined temperature, the control shifts to filter clogging control. Here, the predetermined condensing temperature refers to a temperature within the compressor use reference range shown in FIG.

  In filter clogging control, the user is first prompted to clean the condenser filter by a condenser filter clogging alarm. Further, the rotation speed of the compressor 19 is shifted down by one rank from the current level. Next, the warning time of the condenser clogging alarm is read. If it is within the specified time, the flow returns to the above flow and the condensing temperature and evaporation temperature are read again. When the clogging state of the condenser filter is eliminated and the condensation temperature becomes equal to or lower than a predetermined temperature, the condenser filter clogging alarm is canceled and the routine proceeds to normal operation control.

  Further, when the warning time of the clogging alarm has exceeded a specified time, the control shifts to refrigerant leakage prevention control. In the refrigerant leakage prevention control, an operation abnormality alarm is first warned, the compressor is continuously operated at a specified speed, and the cycle of the defrosting operation is further extended. After that, the condensing temperature is continuously read, and when the condensing temperature falls below a predetermined temperature, the operation abnormality alarm is canceled and the flow returns to the above flow.

  When the filter disposed in the suction portion of the condenser 20 is clogged, the heat exchange capacity of the condenser is reduced, and the air flow into the cooling system is the same as that of the condenser 20. The temperature rises abnormally. Therefore, in the refrigerant leakage prevention control, when the condensing temperature exceeds the predetermined temperature, the compressor filter clogging alarm is used to prompt the user to clean the filter while suppressing the compressor speed to protect the compressor. doing.

  In the normal filter clogging state, the condensation temperature returns to a predetermined temperature or less as the filter is cleaned. However, if the piping is damaged on the low pressure side such as the connection portion of the evaporator 21, the condensation temperature is the predetermined temperature. It does not return to the following. Therefore, when the warning time of the condenser filter clogging alarm continues for a specified time or longer, it can be determined that the refrigerant is leaking, and therefore the control is shifted to the refrigerant leakage prevention control.

  In the refrigerant leakage prevention control, the evaporation pressure is adjusted so that the refrigerant pressure and the atmospheric pressure are balanced so as to maintain a state where the refrigerant does not leak as much as possible and the inflow of air can be minimized. Furthermore, since a large amount of refrigerant leaks during the defrosting operation, the defrosting operation cycle is extended. The reason why the defrosting operation is not stopped here is that a decrease in the evaporation temperature due to the frosting of the evaporator is assumed, and in that case, a large amount of air may be sucked, so it is necessary to perform the defrosting operation appropriately. It is.

  On the other hand, even if the refrigerant is not leaking, if the user does not clean the filter for a long time, there is a possibility that the refrigerant leakage prevention control may occur, but in that case, when the condenser filter is cleaned Can automatically return to normal control. Even if the refrigerant leakage prevention control is entered, the operation abnormality warning display is used instead of the refrigerant leakage warning display, so that the user can be kept from worrying more than necessary even during the erroneous detection.

  As described above, the refrigerator-freezer unit and the refrigerator according to the present invention can avoid the failure of the compressor as much as possible, and can ensure high safety while using a flammable refrigerant with a small global warming potential, and are flammable. The technology can be widely applied to cooling equipment using refrigerant.

Refrigeration cycle diagram of the refrigerator according to Embodiment 1 of the present invention Rotational speed control diagram of a compressor or the like according to the embodiment of the present invention The figure which shows the use reference | standard range of the compressor by the same embodiment of this invention Flow chart of refrigerant leakage prevention control according to the embodiment of the present invention Cross-sectional view of a conventional refrigerator

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Freezer compartment 5 Unit base 19 Capacitance variable type compressor 20 Condenser 21 Evaporator 23 Condenser fan 24 Evaporator fan 25 Controller 26 Compressor control means 27 Alarm transmission means 31 Condensing temperature sensor 32 Evaporation temperature sensor 33 Internal temperature sensor 33 34 Outside air temperature sensor

Claims (8)

A refrigerant having a negative evaporating pressure during cooling operation, a compressor having a variable rotation speed, a condenser, a throttling device, an evaporator, an external fan, and an internal fan, and refrigerant leakage in the vicinity of the evaporator A refrigerating / refrigeration unit comprising: a refrigerant leakage detection means for detecting a refrigerant; and a refrigerant leakage prevention control means for suppressing the rotation speed of the variable speed compressor, and a refrigerator using the refrigerating / refrigeration unit. A condensing temperature detecting means for detecting the condensing temperature; and an evaporating temperature detecting means for detecting the evaporating temperature. The condensing temperature detected by the condensing temperature detecting means is preset by the evaporating temperature detected by the evaporating temperature detecting means. 2. The refrigeration unit and the refrigeration unit according to claim 1, further comprising a refrigerant leakage prevention control that determines that the refrigerant leaks when the temperature is higher than the set temperature and suppresses the rotation speed of the variable speed compressor. Refrigerator using refrigeration unit. A condensation temperature detecting means for detecting the condensation temperature; an evaporation temperature detecting means for detecting the evaporation temperature; and an internal temperature setting means for setting the internal temperature. The condensation temperature detected by the condensation temperature detecting means is the evaporation temperature. When the temperature is higher than the preset temperature by the evaporation temperature detected by the temperature detecting means, it is determined that the refrigerant has leaked, and the internal temperature setting means raises the preset temperature in the compartment to the preset temperature. The refrigerator using the refrigeration unit of Claim 1 characterized by the above-mentioned, and the said refrigeration unit. The refrigerator using the freezing and refrigeration unit according to any one of claims 1 to 3, wherein the condensation temperature detecting means is provided at a condensation start position of the condenser. The refrigerant leakage prevention control for continuously operating the compressor at a specified rotational speed is performed, and the refrigerator using the refrigerator-freezer unit and the refrigerator-freezer unit according to any one of claims 1 to 4. 6. The refrigerant refrigeration unit according to any one of claims 1 to 5 and a refrigerator using the refrigeration unit, wherein the refrigerant leakage prevention control is performed to extend the defrosting operation cycle more than the normal control. 7. The refrigeration unit according to claim 1, further comprising a control unit that warns a user and a unit that warns a user when the operation time of the refrigerant leakage prevention control continues for a predetermined time or more. And a refrigerator using the freezing and refrigeration unit. The refrigerating / refrigeration unit according to any one of claims 1 to 7, wherein when the condensing temperature returns to a normal state during the refrigerant leakage prevention control, the refrigerant leakage prevention control automatically returns to the normal control. Refrigerator using a refrigeration unit.

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