JP2010060177A - Refrigerating cycle device, refrigerating device, and air conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle device and the like capable of accurately determining completion of a defrosting operation by using a frost detecting means, securing reliability of the device, and improving efficiency in the defrosting operation and the device. <P>SOLUTION: This refrigerating cycle device provided with a refrigerant circuit constituted by connecting a compressor 1 for compressing a refrigerant, a condenser 2 for condensing the refrigerant, an expansion valve 3 for decompressing the refrigerant, and an evaporator 4 for evaporating the refrigerant by heat exchange, by piping, further includes the frost detecting means 7 for detecting a condition of frost attached to the evaporator 4, a heater 8a for the evaporator, for heating the evaporator 4, a heater 8b for bottom surface, for heating a bottom surface of a housing receiving the evaporator 4, and a control means 50 for stopping the heating of the heater 8a for the evaporator, and then stopping the heating by the heater 8b for the bottom surface after a prescribed time from the stop of the heating of the heater 8a for the evaporator, when it is determined that the evaporator 4 is free from frost on the basis of a signal from the frost detecting means 7 in the defrosting operation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus that performs a defrosting operation for defrosting an evaporator or the like, for example. In particular, it relates to the end of the defrosting operation.

  Generally, a refrigeration cycle apparatus using a refrigeration cycle (heat pump cycle) such as an air conditioner, a refrigeration apparatus, or a hot water supply apparatus basically includes a compressor, a condenser (heat exchanger), an expansion valve, and an evaporator (heat exchange). A refrigerant circuit that circulates the filled refrigerant. The refrigerant compressed by the compressor becomes a high-temperature and high-pressure gas refrigerant and is sent to the condenser. The refrigerant that has flowed into the condenser is liquefied by releasing heat by heat exchange with the heat exchange object. The liquefied refrigerant is decompressed by the expansion valve to become a gas-liquid two-phase flow state, and is converted into gas (gas) by absorbing heat by heat exchange in the evaporator, and is returned to the compressor and circulated again.

Here, when the temperature in the target space is set to a temperature environment lower than 10 ° C., for example, in a freezer / refrigerated warehouse, the evaporation temperature of the refrigerant in the evaporator installed in the target space is even lower than that. It is necessary to make the temperature (temperature lower than 0 ° C.). At this time, moisture in the air that exchanges heat with the refrigerant condenses, forms frost on the evaporator, and accumulates over time. The accumulated frost causes an increase in thermal resistance, a decrease in the amount of air passing through the fins, and the like, and decreases the ability to cool the air. Therefore, for example, an optical frosting amount detector composed of a light emitting unit and a light receiving unit detects the state of the attached frost, and a defrosting heater (heating means) is attached to the evaporator and the drain pan, and periodically The performance reduction is eliminated by performing a defrosting operation in which the frost is melted by heating (see, for example, Patent Document 1).
JP-A-8-61813 (FIGS. 5 and 6)

  Here, regarding the end of the defrosting operation, for example, when the control unit determines that the temperature related to detection by the temperature detection unit attached to the evaporator (representing the temperature of the evaporator) is equal to or higher than a threshold, The defrosting operation has been terminated by stopping and de-energizing the heater that is heating the vessel and the drain pan. Thus, since the defrosting operation was performed by estimating the state of the frost attached to the evaporator and the drain pan based only on the temperature related to the detection of the temperature detecting means attached to the evaporator, the evaporator and the drain pan are excessive. Was heating. As a result, energy was wasted. Also, if the evaporator etc. are heated excessively, the ambient temperature of the evaporator etc. will rise in the warehouse, for example, moisture may form on the ceiling of the refrigerated / freezer warehouse, causing icicles, etc. There was a problem of narrowing.

  On the other hand, if the determination of the completion of the defrosting operation is wrong and the defrosting operation is terminated early, unmelted frost or the like occurs. The unmelted frost and the like often eventually grow into root ice, but the root ice cannot basically be thawed by a normal defrosting operation. For this reason, the unmelted residue gradually spreads, leading to a reduction in the heat transfer area of the evaporator, and as a result, the cooling performance is greatly reduced.

  The same applies to an air conditioner for air conditioning a living space. For example, in a building or the like, a defrosting operation is performed on an outdoor unit (heat source side unit) that is connected to a plurality of indoor units (indoor units) and has a large amount of heat exchange. The actual situation is that the defrosting operation is not performed efficiently because it is made longer or shorter.

  Therefore, for such a technical problem, the end of the defrosting operation can be accurately determined by using the frost detection means, and the reliability of the device can be ensured, the efficiency of the defrosting operation can be improved, and the efficiency of the device can be improved. It aims at obtaining the refrigerating-cycle apparatus which can be made.

  The refrigeration cycle apparatus according to the present invention includes a compressor that compresses refrigerant, a condenser that condenses the refrigerant by heat exchange, expansion means for depressurizing the condensed refrigerant, and evaporates the decompressed refrigerant by heat exchange. A refrigerating cycle device that constitutes a refrigerant circuit that circulates a refrigerant by connecting a pipe to the evaporator to be circulated, further comprising frost detection means for detecting a state of frost attached to the evaporator, and frost attached to the evaporator. Evaporator heating means for performing heating for melting, bottom surface heating means for performing heating for melting frost attached to the bottom surface of a housing housing the evaporator, and defrosting operation for performing defrosting related to the evaporator At this time, if it is determined that the evaporator frost has disappeared based on the signal from the frost detection means, heating of the evaporator heating means is stopped, and heating of the bottom surface heating means is performed after a predetermined time from the heating stop of the evaporator heating means. System to stop And means.

  According to the refrigeration cycle apparatus of the present invention, when performing the defrosting operation, if the control means determines that the frost attached to the evaporator has disappeared based on the signal from the frost detection means, the evaporator heating means Since heating is stopped and heating by the bottom surface heating means is stopped after a predetermined time and the defrosting operation is terminated, the defrosting operation can be terminated at an appropriate timing. Therefore, for example, useless heating can be eliminated and energy for heating can be reduced.

Embodiment 1 FIG.
The contents of the embodiment according to the present invention will be described below.
FIG. 1 is a diagram showing a basic configuration of a refrigeration cycle apparatus according to Embodiment 1 of the present invention. An arrow 60 in FIG. 1 indicates the direction in which the refrigerant flows. In FIG. 1, the refrigeration cycle apparatus has a compressor 1, a condenser 2, an expansion valve (throttle device) 3 and an evaporator 4, and a refrigerant circuit is formed by connecting the respective devices (element parts) with pipes. Is configured. Here, it is assumed that the refrigeration cycle apparatus of the present embodiment also includes an accumulator 5 that stores, for example, liquefied surplus refrigerant. Moreover, in this Embodiment, the evaporator 4 shall be one of the structural means of the evaporator units 40, such as a cooling device. Further, it has at least a storage means 50a for storing data and the like, a timer 50b for measuring time, and a control means 50 for controlling the operation of each means. A refrigerant to be circulated is sealed in the refrigerant circuit. As this refrigerant, in the present embodiment, R404A widely used for refrigerators is enclosed and circulated. However, the present invention is not limited to this. For example, other refrigerants such as R407C, R410A, CO ₂ , propane, isobutane, ammonia, HFO (hydro-fluoro-olefin), etc. are used in accordance with the temperature range to be cooled. You may do it.

  In order to circulate the refrigerant in the refrigerant circuit, the compressor 1 sucks, compresses and pressurizes the refrigerant. Moreover, the condenser 2 which is a heat exchanger is the quantity of heat which a refrigerant | coolant has by the heat exchange performed between the gas (gas) -like refrigerant | coolant (henceforth a gas refrigerant | coolant) which the compressor 1 discharged, and heat exchange object. Is discharged, condensed and liquefied, and the heat exchange object is heated. The expansion valve 3 adjusts the flow rate of the refrigerant to lower (depressurize) the pressure of the refrigerant.

  FIG. 2 is a perspective view schematically showing the evaporator 4 in the first embodiment. The evaporator 4 is, for example, a gas-liquid two-phase refrigerant (a refrigerant in which a gas refrigerant and a liquid refrigerant (hereinafter referred to as a liquid refrigerant) are mixed) whose pressure has been lowered by the expansion valve 3 and a heat exchange target (here, air). By heat exchange performed between the refrigerant and the refrigerant, the refrigerant absorbs heat and evaporates to be gasified. On the other hand, the air to be heat exchanged is cooled. Here, the level of the pressure in the refrigerant circuit is not determined by the relationship with the reference pressure, but is expressed as a relative pressure that can be generated by the compression of the compressor 1, the refrigerant flow control of the expansion valve 3, etc. To do. The same applies to the temperature level.

  In the present embodiment, the evaporator 4 includes a plate fin tube heat exchanger having a plurality of fins 4a and heat transfer tubes 4b. By transferring the heat of the refrigerant flowing inside the heat transfer tube 4b to the air passing between the fins 4a via the fins 4a, the heat transfer area serving as a contact surface with the air is expanded, and the heat between the refrigerant and the air is increased. Exchange can be done efficiently.

  FIG. 3 is a schematic view of the evaporator unit 40 as viewed from the side. As described above, the evaporator 4 is one of the constituent means of the evaporator unit 40. The evaporator unit 40 of the present embodiment will be described as a cooling device for cooling the inside of a warehouse in a refrigerated / refrigerated warehouse. The evaporator unit 40 of the present embodiment includes an evaporator 4, a frost detection means 7, a defrosting heating means 8, a fan 9, a fan driving means 10 and a temperature detection means 12, and these means are enclosed in a housing. It is stored in the body 41. Here, with respect to the bottom wall of the housing 41, for example, when the evaporator unit 40 is provided indoors as in a cooling device, for example, it has a drain outlet (not shown) connected to a drain pipe, and frost is generated. It is composed of a drain pan that serves as a tray for water generated by melting (hereinafter referred to as drain water). Moreover, when providing in the outdoors etc., it comprises with the base which provided the some through-hole for flowing drain water on the ground, for example. In the present embodiment, since it is a cooling device used in a warehouse, the bottom wall is assumed to be a drain pan 42. The drain pan 42 is not horizontal but is slightly inclined, and has a structure in which drain water collects at the drain port.

  The defrosting heating means 8 included in the evaporator unit 40 includes an evaporator heater 8a and a bottom heater 8b. In the present embodiment, the evaporator heaters 8 a provided in the evaporator 4 are respectively provided on the upper and lower sides and the lower surface of the side surface that is the windward side of the air flow 61 in the evaporator 4. Here, the following description regarding the up and down direction will be given with the vertical direction or a direction close thereto as the up and down direction. The bottom heater 8b provided on the drain pan 42 is provided so as to melt the frost attached to the drain pan 42 and prevent the drain water accumulated in the drain pan 42 from freezing. The control unit 50 can independently control ON (energization, heating) / OFF (energization, heating stop) for the evaporator heater 8a and the bottom heater 8b.

  FIG. 4 is a top view of the evaporator unit 40. The evaporator unit 40 is provided with, for example, a propeller-shaped fan 9 with the back side facing the evaporator 4. In addition, the fan driving means 10 rotates the fan 9 so that the air sucked into the housing 41 passes between the fins 4a and is blown out (discharged) from the air outlet (not shown). A stream 61 is formed. In the present embodiment, the temperature detecting means 12 is provided at the substantially central portion of the side surface of the evaporator 4 where the heat transfer tube 4b is bent (U bent), and controls a signal based on the detected temperature. Transmit to means 50.

  Here, the operation of the refrigeration cycle apparatus according to the present embodiment will be described based on the refrigerant flow. The refrigerant compressed and pressurized by the compressor 1 passes through the piping and is sent to the condenser 2. The refrigerant that has passed through the condenser 2 is condensed and liquefied. At this time, the refrigerant dissipates heat, thereby heating the heat exchange target.

  The liquefied refrigerant is sent to the expansion valve 3. The refrigerant in the liquid state is decompressed by passing through the expansion valve 3 and is sent to the evaporator 4 as a refrigerant in a gas-liquid two-phase flow state (hereinafter referred to as a gas-liquid two-phase refrigerant). The gas-liquid two-phase flow state refrigerant that has passed through the evaporator 4 is evaporated and gasified. The gasified refrigerant is again sucked into the compressor 1.

  When the refrigeration cycle apparatus is operating, for example, when the evaporation temperature of the refrigerant passing through the pipe of the evaporator 4 is lower than 0 ° C, the refrigerant absorbs the heat of the air by heat exchange, while the air is In order to cool, moisture (water vapor) in the air condenses on the tube surface and accumulates as frost. The amount of deposition increases with time.

  FIG. 5 is a schematic configuration diagram of the frost detection means 7 of the first embodiment. As shown in FIG. 5, the frost detection means 7 includes a light emitting element 7a for irradiating light, a light receiving element 7b for converting received light into a signal, a light emitting element 7a, and a driving means 7c for driving the light receiving element 7b. . The light emitting element 7a is constituted by an LED (light emitting diode), for example, and emits light by changing electrical energy to light energy. The LED structurally utilizes a P-type / N-type semiconductor junction. On the other hand, the light receiving element 7b of the present embodiment is made of, for example, a PD (photodiode), and is the same friend as the solar cell. For example, when a semiconductor PN junction is irradiated with light, a photoelectromotive force is generated, and a reverse bias circuit in which a current based on the intensity of light flows is formed. The driving unit 7c supplies power to the light emitting element 7a, and also amplifies the signal of the light receiving element 7b and transmits the amplified signal to the control unit 50 (the intensity of light becomes a voltage signal. This voltage is referred to as output voltage V). By constructing both the light emitting element 7a and the light receiving element 7b with inexpensive materials, the manufacturing cost of the frost detecting means 7 can be greatly reduced and the size can be reduced.

  FIG. 6 is a diagram showing the relationship between the frost detection means 7 and the fins 4a of the evaporator 4. For example, when the accumulation width of frost from the surface of the fin 4a becomes a predetermined width, reflected light having a predetermined light intensity or more is incident on the light receiving element 7b. The control unit 50 determines the light intensity based on the signal from the frost detection unit 7 and determines the frosting state on the surface of the fin 4 a of the evaporator 4. And if it judges that it is the light more than predetermined intensity | strength, it will be made to start a defrost operation. Moreover, in this Embodiment, the control means 50 also judges whether a defrost operation is complete | finished based on the signal from the frost detection means 7. FIG. Here, the defrosting in the present embodiment means that the frost attached to the surfaces of the fins 4a and the heat transfer tubes 4b (hereinafter referred to as fins 4a and the like) melts, and the sherbet-like frost and frost are water droplets. It is assumed that there is no dew etc. (hereinafter referred to as dew etc.), drain water is drained and does not remain in the drain pan 42, etc., and the defrosting operation is terminated in a defrosted state. To do.

  In the case of the plate fin tube heat exchanger described above, the distance between the adjacent fins 4a and fins 4a (hereinafter referred to as fin pitch) increases the heat transfer area. It is as narrow as 2 to 10 [mm]. In the frost detection means 7, it is necessary to receive the reflected light related to the light emitted from the light emitting element 7a in the direction of the fin 4a by the light receiving element 7b in such a narrow fin pitch. In addition, since the frost detection means 7 is installed in the air passage through which air passes, it is necessary to prevent the wind speed distribution in the evaporator 4 from being affected by reducing the size as much as possible. is there. Here, if the frost detection means 7 is formed from a separate part that can be attached to and detached from the evaporator 4 and can be attached to an existing refrigeration cycle apparatus, it can be attached to existing equipment to detect frost, The reliability of the apparatus is improved and the efficiency can be improved.

  Next, the position where the frost detection means 7 is attached will be described. In the evaporator 4, if the defrosting is not complete and the operation is shifted to the normal operation, the dew etc. attached to the fins 4 a or the like can be frozen again or blown out of the evaporator unit 40 by the wind generated by the fan 9. There is sex. This results in reduced reliability in the cooling device. For this reason, it is desirable to shift to the normal operation after determining that at least the evaporator 4 is completely dewless. On the other hand, if heating is continued in the evaporator 4 even though no dew is attached to the fins 4a and the like, power is consumed for useless heating. In addition, it takes time to raise the temperature of the target space such as a refrigerated / refrigerated warehouse and cool it again in normal operation. It is desirable that it is possible to accurately determine whether or not the fins 4a and the like are completely free of dew or the like so as not to be too early or too late.

  Here, although the frost is melted by the heating of the defrosting heating means 8, the temperature of the ambient air around the evaporator heater 8 a and the bottom heater 8 b is also low in an environment where the temperature of the air is low, such as a refrigeration / freezer warehouse. Rise and warm up. Since the warm air moves to the upper part, the frost attached to the upper part of the evaporator 4 is heated by the fins 4a and the air, and the frost attached to the upper part of the evaporator 4 is melted from the frost attached to the lower part. It becomes easy. Further, dew or the like formed by melting of the frost on the upper portion drops on the lower evaporator heater 8a and takes the heat of the lower evaporator heater 8a, so that the efficiency of the lower evaporator heater 8a is deteriorated. From the above, in the evaporator 4, frost is less likely to melt in the lower part, and dew etc. is likely to remain.

  In addition, as a result of many years of research by the inventor, the wind suction side (evaporation) except for special conditions (when the doors of the refrigerated / refrigerated warehouse are open and closed frequently and the refrigerated / refrigerated warehouse moves up and down around 0 ° C) The amount of frost formation on the windward side of the vessel 4 is larger than that of other portions. Therefore, it is known that it takes time to melt the frost on the windward side.

  Therefore, if the frost detection means 7 is attached at a position below the evaporator 4 and on the windward side, the frost state at a position where the time until the evaporator 4 melts most (until dew etc. disappears) is long. Will be detected. Therefore, the end of the defrosting operation can be determined more accurately, and the efficiency of the apparatus can be improved.

  FIG. 7 is a diagram illustrating an example of the relationship between the state of the fins 4a and the like, the amount of drain water, and time during the defrosting operation. Here, in FIG. 7, the vertical axis represents the output voltage [V] of the signal related to the detection of the frost detection means 7 and the amount of drain water (the integrated value of the discharged drain water) [kg] related to the discharge from the drain pan 42. The horizontal axis represents time t [s]. In addition, it is assumed that the defrosting operation starts at time 0 [s].

  First, the state of the fins 4a and the like will be described. In the section A shown in FIG. 7, heating of the evaporator 4 is started by the evaporator heater 8a, and heating of the drain pan 42 is started by the drain pan heater 8b. In the section A, the frost accumulated on the fins 4a and the like has not yet melted, and the state of the fins 4a and the like has not changed at all. Therefore, the output voltage V of the signal related to detection by the frost detection means 7 is substantially constant. The state continues.

  The section B is a state in which the frost accumulated on the fins 4a and the like has started to melt, and indicates that changes have occurred in the fins 4a and the like. The section C is a state in which the frost accumulated on the fins 4a and the like is melted and dew is dripping. When dew etc. pass through the fins 4a and the like, and the strong reflected light temporarily enters the light receiving element 7b, the fluctuation (vibration) of the output voltage V of the signal related to the detection of the frost detection means 7 becomes large (varies). . In the section D, dew etc. is dripped and no dew etc. remains on the fins 4a etc. (surface is dry). Since the state of the fins 4a and the like does not change, the output voltage of the signal related to detection by the frost detection means 7 hardly changes. When the state of each section is examined, in the section C, since dew etc. remains on the fins 4a and the like, the evaporator heater 8a is turned off as close as possible to the start of section D (section C ends). It is desirable to make it.

  As described above, it can be said that there is a clear correlation between the output voltage of the signal related to detection by the frost detection means 7 and the state of the fins 4a and the like. Therefore, if such a pattern is used, it is possible to accurately determine the end of the defrosting operation.

  Next, the amount of drain water will be described with reference to FIG. In FIG. 7, drain water begins to flow from about 600 [s]. In addition, the drain water is completely drained since it is almost in the vicinity of about 1600 [s]. The fins 4a and the like are free of dew, etc., at the final point of the section C (the starting point of the section D, around 1100 [s]), and there is a deviation from the time when the drain water amount is in an equilibrium state. ing. This is because the drain water cannot be completely drained and is accumulated in the drain pan 42, and it takes time to drain the drain water from the drain pan 42.

  As described above, drain water is accumulated in the drain pan 42 even if the dew or the like disappears in the fins 4a. Therefore, when it is determined that the evaporator 4 is free of frost and dew, if the bottom heater 8b is turned off simultaneously with the heater 8a for the evaporator, the drain water collected in the drain pan 42 is frozen, and the drain water Of poor drainage. Therefore, if the bottom heater 8b is turned off when the drain water is in an equilibrium state after the evaporator heater 8a is turned off, the drain water is not left and the defrosting operation can be performed efficiently.

  FIG. 8 is a diagram showing a flowchart showing a basic flow of control processing related to the defrosting operation performed by the control means 50. Based on the signal from the frost detection means 7, the control means 50 determines that the state shown in the section D (about 1100 [s]) in FIG. 7 has been reached (A1). At this time, since there is no frost or the like on the fin 4a, the evaporator heater 8a is turned off (A2).

  On the other hand, if the temperature, time, etc. of the evaporator 4 at which the total amount of drain water is balanced are determined in advance from tests, etc., and it is determined that the temperature, time, etc. have reached (A3), the drain water is drained, and the drain pan. It is determined that it has disappeared from 42. Then, the bottom heater 8b is turned off (A4).

  By performing the control process according to the flow of A1 to A4, the evaporator heater 8a is turned off and only the bottom heater 8b is turned on in the section D where the dew or the like has disappeared in the fins 4a and the like. Can be reduced. The bottom heater 8b is turned off based on the temperature and time of the evaporator 4 when the evaporator heater 8a is turned off, and the defrosting operation is completed. It is possible to suppress the generation of frost and icicles in a refrigerated / refrigerated warehouse.

  FIG. 9 is a diagram showing a control flow in the defrosting operation by the control means 50 according to the first embodiment. Based on FIG. 9, the determination process related to the end of the defrosting operation will be described in particular. The control means 50 stops the flow of the refrigerant in the refrigerant circuit and then starts the defrosting operation (S0). Then, the evaporator heater 8a and the bottom heater 8b are turned on to start heating (S1). Further, it is determined whether or not a certain time (for example, 3 minutes) has passed (S2). This is to prevent the determination process of the section D (end of the section C) shown below from being performed in the time zone of the section A.

  If it is determined that a certain period of time has elapsed, the output voltage V based on the signal from the frost detection means 7 and the value of the evaporator temperature T based on the signal from the temperature detection means 12 are determined at regular intervals (for example, every 5 seconds). Then, the process of storing those values as data in the storage means 50a is started (S3).

  When data of at least five output voltages V is stored in the storage means 50a, the past five output voltages V (V (n), V (n-1), V (n-2), V (n -3) and V (n-4)), the standard deviation σ is obtained (S4).

  In the section C of FIG. 7, when the frost or the like of the fins 4a is dripping, the output voltage V related to the signal from the frost detection means 7 vibrates and the variation becomes large. Therefore, the standard deviation σ in the section C increases. Therefore, the characteristics of the output voltage V in the section C are used to determine whether or not the section D has been entered. Therefore, a standard deviation threshold σb (hereinafter referred to as a threshold standard deviation σb) is determined in advance by a test or the like and stored in the storage unit 50a. Based on the comparison between the calculated standard deviation σ and the threshold standard deviation σb, the control means 50 determines whether or not the section D has been reached (whether or not the section C has ended).

Here, for example, in order to save the memory (the storage capacity stored in the storage unit 50a) of the control unit 50, the standard deviation σ is obtained by storing data related to the past five detections. As the number of data increases, the accuracy of the standard deviation σ can be increased, and the determination of the section D can be performed more accurately. In the present embodiment, the standard deviation σ is calculated in order to determine the fluctuation of the output voltage V. For example, the variance σ ² may be calculated instead of the standard deviation σ.

  If the control means 50 determines that the standard deviation σ is smaller than the threshold standard deviation σb (standard deviation σ <threshold standard deviation σb), the control means 50 determines that the output voltage V is stable and has become the section D. . Here, if the standard deviation σ is smaller than the threshold standard deviation σb once and becomes the section D, there is a concern that the determination is erroneous. Therefore, in the present embodiment, from the viewpoint of preventing misjudgment, when the standard deviation σ <threshold standard deviation σb is continuously judged three times (S5), it is assumed that the fins 4a and the like are free of frost and the like, and the evaporator heater 8a Is turned OFF (S6).

  FIG. 10 is a diagram illustrating an example of the relationship between the evaporator temperature T and the time t during the defrosting operation. Next, control for determining the timing for turning off the bottom heater 8b will be described. In FIG. 10, the solid line represents the change in the evaporator temperature T when the evaporator heater 8 a is turned on until the point F at which the drain water disappears in the drain pan 42. Let the evaporator temperature T at point F be Tb. On the other hand, the broken line represents the change in the evaporator temperature T when the evaporator heater 8b is turned off at the point G where the dew or the like disappears in the fins 4a and the like.

  In the solid line, the evaporator heater 8a continues to be in an ON state even when the dew or the like disappears in the fins 4a and the like, so that the evaporator temperature T rises as time elapses to near the point F. On the other hand, in the broken line, since the evaporator heater 8a is turned off at point G, the evaporator temperature T once rises due to residual heat, but decreases with the passage of time after a certain time. In the present embodiment, as described above, when it is determined that the dew or the like has disappeared in the fins 4a and the like, the evaporator heater 8a is turned off, so the change in the evaporator temperature T is as shown by a broken line.

  Here, based on the evaporator temperature T, for example, the test condition is changed, a broken line as shown in FIG. 10 is created for each condition, and the threshold of the evaporator temperature T for judging the timing to turn off the bottom heater 8b. However, since the evaporator temperature T is likely to change depending on the ambient temperature of the evaporator 4, the wind, etc., there is a concern about frequent detection.

  On the other hand, it can be seen from the solid line in FIG. 10 that the evaporator temperature T changes substantially linearly between the point G and the point F when the evaporator heater 8a is kept on. Therefore, in the present embodiment, the timing for turning off the bottom heater 8b is determined based on the data of the evaporator temperature T before turning off the evaporator heater 8a (ON state of the evaporator heater 8a). .

  Therefore, when the controller 50 continues the state in which the evaporator heater 8a is turned on from the data of the evaporator temperature T up to the point G in FIG. Time tb until Tb is obtained by extrapolation. When it is determined that the time tb has elapsed since the evaporator heater 8a was turned off at point G, the bottom heater 8b is turned off.

  The above process will be further described with reference to FIG. In S3, the control means 50 performs a process of storing the evaporator temperature T data in the storage means 50a. Therefore, when the evaporator heater 8a is turned off in S6, the data of the evaporator temperature T for the past 20 detections including the evaporator temperature Tend at the point G are used to determine the point G based on the least square method, for example. A slope α (= dT / dt) of the evaporator temperature T is obtained (S7). Here, the inclination α is obtained from the data of the evaporator temperature T stored for the past 20 detections in relation to the storage capacity, but the number of data used for the calculation is not limited to 20. If the number of data is reduced, the calculation can be performed quickly. Conversely, the greater the number of data, the higher the accuracy of the slope.

Next, a time tb until the bottom surface heater 8b is turned off is calculated based on Tend as the evaporator temperature at point G, the calculated inclination α, and the evaporator temperature Tb at point F determined in advance by a test or the like ( S8). Here, the time tb is expressed by the following equation (1).
tb = (Tb−Tend) / α (1)

  When it is determined that the time tb has elapsed since the time when the evaporator heater 8a was turned on based on the time counted by the timer 50b (S9), the control means 50 turns off the bottom heater 8b (S10), The defrosting operation is terminated (S11).

  FIG. 11 is a diagram showing a control flow during the pre-cooling operation by the control means 50. When the defrosting operation is completed in S11 described above, the control unit 50 starts the precooling operation (S20). Since the evaporator 4 is heated and heated during the defrosting operation, when the fan 9 is operated in this state, hot air is blown out to the surroundings, leading to an increase in the indoor temperature. Therefore, a pre-cooling operation for cooling the evaporator 4 is performed before the normal operation is started.

  Therefore, without operating the fan 9, the solenoid valve provided in the refrigerant circuit such as the expansion valve 3 is opened (S21), and the drive of the compressor 1 is started (S22). Thereby, a low temperature refrigerant | coolant is poured through the heat exchanger tube 4b of the evaporator 4, and the evaporator 4 is cooled. At this time, the precooling time is measured based on the time measured by the timer 50b (S23).

  When it is determined that the precooling time has elapsed (S24), the rotation of the fan 9 is started (S25), the timer 50b is reset (S26), the precooling operation is terminated (S27), and the normal operation process is performed. (S28).

  As described above, according to the refrigeration cycle apparatus of the first embodiment, when performing the defrosting operation for removing frost attached to the evaporator 4 and the like by the operation of the refrigerant circuit, the evaporator 4 of the evaporator unit 40. When the control means 50 determines that the frost attached to the evaporator 4 has disappeared based on the signal from the frost detection means 7 for the heater 8a for the evaporator provided on the heater 8 and the heater 8b for the bottom face provided on the drain pan 11. Since the evaporator heater 8a is turned off and the bottom heater 8b is turned off after the time to end the defrosting operation, the defrosting operation can be ended at an appropriate timing.

  Therefore, it is not necessary to continue heating both the evaporator heater 8a and the bottom heater 8b unnecessarily for a long time until the end of the defrosting operation. Therefore, for example, in the evaporator unit 40 such as a cooling device provided for refrigeration / freezing in a refrigeration / freezer warehouse or the like, power consumption due to useless heating can be suppressed. At the same time, for example, it is possible to prevent temperature rise in the warehouse due to wasted heat, prevent deterioration of the quality of goods in the warehouse, and form icicles etc. by attaching moisture to the ceiling in the warehouse. Nothing will happen. On the contrary, the generation of root ice can be prevented without ending the defrosting operation early. Therefore, the reliability of the refrigeration cycle apparatus can be greatly improved, and the efficiency can be improved. And since the useless heating time of the defrosting heating means 8 is reduced, the life of the apparatus can be extended.

  Further, by using the frost detecting means 7 as an optical detecting means having the light emitting element 7a and the light receiving element 7b, the frost detecting means 7 can be made of an inexpensive material and can be downsized. Then, the control means 11 calculates the standard deviation based on the intensity of the reflected light for a plurality of past times, and the fluctuation of the intensity of the reflected light caused by melting of frost and falling dew etc. is settled. When it is determined that the frost attached to the evaporator 4 has disappeared, the evaporator heater 8a is turned off. Therefore, the state of the frost in the evaporator 4 is accurately detected, and the evaporator heater 8a is appropriately detected. Can be turned off. At this time, by not performing the above determination for a predetermined time from the start of the defrosting operation, it is possible to exclude a portion with a small fluctuation at the stage where the frost is not melted, and thus the heater 8a for the evaporator is turned off. The timing can be determined more accurately.

  Further, based on the signal from the temperature detection means 12 provided in the evaporator 4, the control means 50 calculates the inclination α based on the past predetermined number of temperatures, and when the evaporator heater 8a is turned off. Based on the difference between the temperature of the evaporator 4 and the temperature at the end of the defrosting operation when the evaporator heater 8a is not turned off and the inclination α, the evaporator heater 8a is turned off and the bottom heater 8b is turned off. Since the time tb until turning off is calculated, the defrosting operation can be terminated at an appropriate timing.

Embodiment 2. FIG.
FIG. 12 is a diagram illustrating an air-conditioning apparatus according to Embodiment 2 of the present invention. The refrigeration cycle apparatus of the first embodiment has been described as having a cooling device for cooling a refrigeration / freezer warehouse or the like. In the present embodiment, the case where the above-described refrigeration cycle apparatus of the first embodiment is an air conditioner will be described.

  The air conditioning apparatus of FIG. 12 includes a heat source side unit (outdoor unit) 100 and a load side unit (indoor unit) 200, which are connected by a refrigerant pipe, and are a main refrigerant circuit (hereinafter referred to as a main refrigerant circuit). And the refrigerant is circulated. Among the refrigerant pipes, a pipe through which a gaseous refrigerant (gas refrigerant) flows is referred to as a gas pipe 300, and a pipe through which a liquid refrigerant (liquid refrigerant, which may be a gas-liquid two-phase refrigerant) flows is referred to as a liquid pipe 400. FIG. 11 shows the case of one heat source side unit 100 and two load side units 200 (200a, 200b, which will be described without adding a suffix unless otherwise distinguished). Is not particularly limited.

  In the present embodiment, the heat source side unit 100 includes a compressor 101, an oil separator 102, a four-way valve 103, a heat source side heat exchanger 104, a capillary tube 105, an accumulator 106, a bypass pipe 107, a heat source side fan 108, and a heat source side. Each device (means) includes an on-off valve 109, a heat exchanger 110 between refrigerants, and a bypass expansion device 111.

  The compressor 101, like the compressor 1 in the first embodiment, compresses the sucked refrigerant, applies an arbitrary pressure based on the operating frequency, and sends out (discharges) it. Here, although not particularly mentioned in the first embodiment, for example, the capacity (the amount of refrigerant sent out per unit time) can be changed by arbitrarily changing the operating frequency, and the capacity is variable with the inverter circuit. It is good also as an inverter compressor.

  The oil separator 102 separates the lubricating oil discharged from the compressor 101 together with the refrigerant. The separated lubricating oil is returned to the compressor 101 with the flow rate controlled by the capillary 105. The four-way valve 103 switches the refrigerant flow between the cooling operation and the heating operation based on an instruction from the control means 50. In the present embodiment, switching for performing the defrosting operation is also performed particularly during the heating operation. The accumulator 106 is a means for storing, for example, liquefied surplus refrigerant.

  FIG. 13 is a view of the heat source side unit 100 as viewed from the heat source side heat exchanger 104. The heat source side heat exchanger 104 performs heat exchange between the refrigerant and air (outdoor air). For example, during the heating operation, it functions as the evaporator 4 in the first embodiment, performs heat exchange between the low-pressure refrigerant flowing from the liquid pipe 400 side and the air, and evaporates and vaporizes the refrigerant. Further, during the cooling operation, it functions as a condenser and performs heat exchange between the refrigerant compressed in the compressor 101 flowing in from the four-way valve 103 side and air, thereby condensing and liquefying the refrigerant. Further, the heat source side unit 109 is provided with a heat source side fan 109 for efficiently performing heat exchange between the refrigerant and air in the heat source side heat exchanger 104 corresponding to the fan 9 in the first embodiment.

  In the first embodiment described above, the bottom surface of the evaporator unit 40 is the drain pan 42. However, the heat source side unit 100 according to the present embodiment can discharge drain water to the ground or the like by being provided outdoors. As shown in FIG. The base 112 serves as a support for placing the compressor 101 and the heat source side heat exchanger 104, and has a through hole for discharging drain water to the ground or the like. Here, drain water can be discharged to the ground or the like, but if dew or the like remains on the base 112, it becomes root ice. Therefore, as in the first embodiment, the base 112 is also provided with a bottom heater 8b.

  The flow rate of the inter-refrigerant heat exchanger 110 and the bypass expansion device 111 is adjusted by, for example, the liquid (high temperature and high pressure) refrigerant (liquid refrigerant) flowing out from the heat source side heat exchanger 104 and the bypass expansion device 111 during the cooling operation. It is an apparatus for supercooling the refrigerant supplied to the load side unit 200 by exchanging heat with a low-temperature and low-pressure refrigerant. The liquid flowing through the bypass throttle device 111 is returned to the accumulator 106 via the bypass pipe 107. The accumulator 106 is a device for storing, for example, liquid surplus refrigerant. The heat source side on-off valve 109 is closed during the defrosting operation based on an instruction from the heat source side control device 131 to prevent the refrigerant from passing between the heat source side unit 100 and the liquid pipe 300.

  On the other hand, the load side unit 200 (200a, 200b) includes a load side heat exchanger 201 (201a, 201b), a load side expansion device (expansion valve) 202 (202a, 202b), and a load side fan 203 (203a, 203b). Composed. The load side heat exchanger 201 performs heat exchange between the refrigerant and air. For example, it functions as a condenser during heating operation, performs heat exchange between the refrigerant flowing in from the gas pipe 300 and air, condenses and liquefies the refrigerant (or gas-liquid two-phase), and moves to the liquid pipe 400 side. Spill. On the other hand, during the cooling operation, it functions as an evaporator, performs heat exchange between the refrigerant and the air whose pressure is reduced by the load-side throttle device 202, causes the refrigerant to take heat of the air, evaporates it, and vaporizes it. It flows out to the piping 300 side. In addition, the load side unit 200 is provided with a load side fan 203 having a constant speed, for example, for adjusting the flow of air for heat exchange. The speed of the load-side fan 203 is determined by, for example, user settings.

  The load side expansion device 202 is provided to adjust the pressure of the refrigerant in the load side heat exchanger 201 by changing the opening degree, similarly to the expansion valve 3 in the first embodiment. Moreover, in this Embodiment, the flow of a refrigerant | coolant is interrupted | blocked by closing at the time of a defrost operation.

  The air conditioner of the present embodiment allows a high-temperature refrigerant to pass through the heat transfer tubes of the heat source side heat exchanger 104 instead of heating the heat source side heat exchanger 104 by the evaporator heater 8a in the first embodiment. A defrosting operation by a so-called reverse method, which is heated, is performed. Since the load side heat exchanger 201 basically does not perform the defrosting operation, the defrosting operation of the heat source side heat exchanger 104 will be described here. However, the load side heat exchanger 201 does not hinder the defrosting operation. Absent.

  Next, the flow of the refrigerant in the defrosting operation will be described. The defrosting operation in the air conditioner is basically performed by interrupting the heating operation in which the heat source side heat exchanger 104 functions as an evaporator. Here, the control means 50 switches the four-way valve 103 to be the same as in the cooling operation. Then, the valves are controlled so that the bypass expansion device 111 is opened and the heat source side opening / closing valve 109 is closed. At this time, since noise may be generated due to pressure fluctuations in the piping at the time of switching, etc., the operating frequency of the compressor 101 is once lowered and switched to the operating frequency in the defrosting operation. To control. Then, the heat source side fan 108 is also stopped. Further, the load side expansion device 202 in the load side unit 200 is closed.

  The high-temperature and high-pressure gas refrigerant discharged from the compressor 101 reaches the heat source side heat exchanger 104 via the oil separator 102 and the four-way valve 103. When the gas refrigerant passes through the heat source side heat exchanger 104, the frost absorbs heat and melts by heat exchange with the frost. The gas refrigerant that has flowed into the heat source side heat exchanger 104 dissipates heat by heat exchange, liquefies slightly, and flows out.

  The refrigerant that has flowed out passes through the bypass pipe 107 via the inter-refrigerant heat exchanger 110 and the bypass expansion device 111. By passing through the bypass expansion device 111, the refrigerant becomes a low-temperature, low-pressure two-phase refrigerant. Here, in order to efficiently perform the defrosting operation, the larger the pipe diameter of the bypass pipe 107, the faster the circulation speed of the refrigerant, so that the time for the defrosting operation can be shortened.

  The two-phase refrigerant that has passed through the bypass pipe 107 flows upstream of the accumulator 106. Basically, the liquid refrigerant is stored in the accumulator 106, and almost only the gas refrigerant is sucked into the compressor 101 and discharged by re-pressurization. Since the heat source side opening / closing valve 109 and the expansion device 202 are closed, the refrigerant does not flow into the load side unit 200. And when dew etc. disappear from the heat source side heat exchanger 104, the four-way valve 103 is switched and the heating operation is started.

  FIG. 14 is a diagram showing a control flow in the defrosting operation by the control means 50 according to the second embodiment. Based on FIG. 14, the determination process which concerns on completion | finish of a defrost operation especially is demonstrated. The control means 50 starts the defrosting operation (S30). At this time, as described above, the four-way valve 103 is switched to be the same as in the cooling operation (S31), and the high-temperature gas refrigerant discharged from the compressor 101 passes through the heat source side heat exchanger 104. . Then, the bottom heater 8b is turned on to start heating (S32). Further, it is determined whether or not a certain time (for example, 3 minutes) has passed (S33). Here, the bottom heater 8b is turned on after switching the four-way valve 103, but the reverse may be possible.

  If it is determined that a certain period of time has elapsed, the value of the output voltage V based on the signal from the frost detection means 7 is determined at regular intervals (for example, every 5 seconds), and the process of storing the data in the storage means 50a is started. (S34). As in the first embodiment, when at least five output voltage V data are stored in the storage means 50a, the standard deviation σ is obtained based on the past five output voltage V data (S35).

  Then, when the control means 50 determines that the standard deviation σ is smaller than the threshold standard deviation σb (standard deviation σ <threshold standard deviation σb) three times continuously, it becomes section D (section C is ended). Judgment is made (S36). Then, the four-way valve 103 is switched to start the heating operation (S37). Thus, heating operation can be restarted quickly by accurately determining the section D.

  Here, when the bottom surface of the housing is the base 112 as in the heat source side unit 100, drain water is unlikely to accumulate like the drain pan 42 in the first embodiment, but when the bottom heater 8b is turned off immediately, The sherbet-like frost that has remained unmelted may accumulate as root ice and the like, which may reduce the heat transfer area of the heat source side heat exchanger 104. Therefore, after the four-way valve 103 is switched and the heating operation is started, the bottom heater 8b is continuously turned on for a predetermined time tc. Here, the predetermined time tc is determined in advance by a test or the like.

  When it is determined that the time tc has elapsed since the start of the heating operation based on the time counted by the timer 50b (S38), the control unit 50 turns off the bottom heater 8b (S39), and performs the defrosting operation. Is finished (S40).

  As described above, the control means 50 is the same as that of the first embodiment even in the so-called reverse method in which the heat source side heat exchanger 104 (evaporator) is heated with a high-temperature refrigerant as in the air conditioner of the second embodiment. The end of the defrosting operation similar to that described can be determined. Moreover, since it is possible to accurately determine that no dew etc. remains in the heat source side heat exchanger 104 based on the intensity of the reflected light related to the detection of the light detection means 7 represented by the output voltage V, Heating operation can be resumed quickly.

Embodiment 3 FIG.
In the first and second embodiments described above, it is determined whether or not a certain period of time has elapsed in order not to perform the determination process for the section D in the section A. In the present embodiment, the following determination is added together with the determination processing for the section D, so that it is not determined that the section D is the section D in the section A. Therefore, the output voltage V _int obtained from the signal from the frost detection means 7 when the defrosting operation is started is stored as data in the storage means 50a.

Based on the signal from the frost detection means 7, it is determined whether the output voltage V is V <K × V _int . When it is determined that V <K × V _int , a count is performed. For example, it is determined that V <K × V _int at least three times, and the standard deviation σ <described in the first embodiment is satisfied. If the threshold standard deviation σb is continuously determined three times, the evaporator heater 8a is turned off as in the first embodiment, assuming that the fins 4a and the like are free of frost and the like.

Here, K is a constant and is a value of 0.5 or less. The section with little fluctuation is the section A and the section D, but the output voltage V is greatly different between the state of the section A where the frost is accumulated on the fins 4a and the like and the state of the section D where the dew is no longer present. Further, for example, when the fins 4a and the like are dewed, there is a characteristic that the output voltage approaches the base value (the output voltage V when nothing is attached to the fins 4a and the like). And the output voltage V in the state where dew etc. disappeared is smaller than the output voltage V in the state where frost accumulated on the fins 4a and the like. From the above, the threshold value K × V _int is set with K being 0.5 or less, and the control means 50 determines whether or not the output voltage V is less than half of the output voltage V _int when the defrosting operation is started. By doing so, it is determined that it has become the section D in the section A.

As described above, according to the refrigeration cycle apparatus of the third embodiment, V <K × V using the value obtained by multiplying the output voltage V _int when defrosting operation is started by a constant K of 0.5 or less as a threshold value. _{If int} is not judged at least three times or more, the state of section A and the state of section D can be determined by not turning off the evaporator heater 8a even if the standard deviation σ <threshold standard deviation σb is judged three times continuously. It is possible to distinguish and prevent the section A from being determined to be the section D. For this reason, the part with a small fluctuation | variation in the stage where the frost does not melt | dissolve can be excluded, and the timing which turns off the heater 8a for evaporators can be judged more correctly.

  In the embodiment described above, application to a refrigeration apparatus and an air conditioner has been described. The present invention is not limited to these devices, and can also be applied to other refrigeration cycle devices having a refrigerant circuit and having an evaporator, such as a heat pump device.

It is a figure which shows the basic composition of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a perspective view which shows the evaporator 4 in Embodiment 1. FIG. It is the figure which looked at the evaporator unit 40 from the side surface. It is the figure which looked at the evaporator unit 40 from the top. It is a schematic block diagram of the frost detection means 7 of Embodiment 1. It is a figure showing the relationship between a frost detection means and the fin 4a of the evaporator 4. FIG. It is a figure showing the state of the fin 4a at the time of a defrost driving | operation, the relationship between drain water and time. It is a figure which shows the basic flow of the control processing regarding a defrost driving | operation. It is a figure which shows the flow of control in the defrost operation by the control means. It is a figure showing an example of the relationship between the evaporator temperature T at the time of a defrost operation, and the time t. It is a figure which shows the flow of control at the time of the precooling driving | operation by the control means. It is a figure showing the air conditioning apparatus which concerns on Embodiment 2 of this invention. It is the figure which looked at the heat source side unit 100 centering on the heat source side heat exchanger 104. FIG. It is a figure which shows the flow of control in the defrost operation which concerns on Embodiment 2. FIG.

Explanation of symbols

  1 compressor, 2 condenser, 3 expansion valve, 4 evaporator, 4a fin, 4b heat transfer tube, 5 accumulator, 7 frost detection means, 7a light emitting element, 7b light receiving element, 7c driving means, 8 heating means for defrosting, 8a Evaporator heater, 8b Bottom heater, 9 Fan, 10 Fan drive means, 12 Temperature detection means, 40 Evaporator unit, 41 Housing, 42 Drain pan, 50 Control means, 50a Storage means, 50b Timer, 60 Flow of refrigerant , 61 Air flow, 100 Heat source side unit, 101 Compressor, 102 Oil separator, 103 Four-way valve, 104 Heat source side heat exchanger, 105 Capillary tube, 106 Accumulator, 107 Bypass piping, 108 Heat source side fan, 109 Heat source side open / close Valve, 110 heat exchanger between refrigerants, 111 bypass throttling device, 112 base, 200, 201a, 201b Load side unit, 201, 201a, 201b Load side heat exchanger, 202, 202a, 202b Load side expansion device, 300 gas piping, 400 liquid piping.

Claims (10)

A pipe connecting a compressor for compressing the refrigerant, a condenser for condensing the refrigerant by heat exchange, an expansion means for decompressing the condensed refrigerant, and an evaporator for evaporating the decompressed refrigerant by heat exchange A refrigeration cycle apparatus constituting a refrigerant circuit for circulating the refrigerant,
Frost detection means for detecting the state of frost attached to the evaporator;
Evaporator heating means for heating the evaporator;
Heating means for the bottom surface for heating the bottom surface of the housing for housing the evaporator;
In the defrosting operation for performing the defrosting related to the evaporator, if it is determined that the frost of the evaporator has disappeared based on the signal from the frost detecting means, the heating of the evaporator heating means is stopped, A refrigeration cycle apparatus comprising: a control unit that performs a process of stopping heating of the bottom surface heating unit after a predetermined time from the stop of heating of the evaporator heating unit. Instead of providing the heating means for the evaporator,
The refrigeration cycle apparatus according to claim 1, wherein the refrigerant discharged from the compressor is heated by flowing through the evaporator.   The frost detecting means receives light reflected by the evaporator or accumulated frost, and transmits a signal based on the intensity of the reflected light. The refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is an optical detection unit having a light receiving element.   When the control means determines that the fluctuation in the intensity of the reflected light caused by the water that has melted frost has converged based on the signal from the frost detection means, the frost in the evaporator has disappeared. 4. The refrigeration cycle apparatus according to claim 3, wherein the heating of the heating means for the evaporator is judged and stopped.   The control means, based on the most recent reflected light intensity data from the frost detection means, to calculate the variation of the intensity of the reflected light as a standard deviation, the calculated standard deviation, 5. The refrigeration cycle apparatus according to claim 4, wherein when it is determined that the predetermined standard number of times is lower than a predetermined standard deviation value, it is determined that the fluctuation has converged. Temperature detecting means for transmitting a signal related to the temperature of the evaporator,
When the control means determines that the evaporator frost has disappeared, it calculates a temperature gradient from a plurality of temperature data of the evaporator until the frost disappears, and the evaporator frost has disappeared. 6. The refrigeration cycle apparatus according to claim 1, wherein the predetermined time is calculated based on a temperature of the evaporator, a predetermined temperature, and a gradient of the temperature when it is determined. .   6. The refrigeration cycle according to claim 4, wherein the control unit is configured not to determine whether or not the fluctuation of the intensity of the reflected light has converged for a predetermined time from the start of the defrosting operation. apparatus.   The control means determines a threshold based on the intensity of the reflected light when the defrosting operation is started, and the intensity of the reflected light exceeds the threshold based on a signal from the frost detection means. 6. The refrigeration cycle apparatus according to claim 4 or 5, wherein if it is determined that the fluctuation of the intensity of the reflected light has converged, it is determined.   A refrigeration apparatus that cools a target space by the refrigeration cycle apparatus according to any one of claims 1 to 8.   An air conditioner that performs cooling and heating of a target space by the refrigeration cycle apparatus according to any one of claims 1 to 8.

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