JP7309064B2 - refrigeration cycle equipment - Google Patents

Description

The present disclosure relates to a refrigeration cycle device in which refrigerant circulates through a circulation flow path connecting a compressor, a condenser, a pressure reducing device, and an evaporator.

In the refrigeration cycle device, when excessive liquid refrigerant sucked into the compressor causes liquid return, the lubricating oil in the sliding parts of the compressor is diluted, and this influences the sliding parts of the compressor to be properly lubricated. may not be available. Therefore, liquid return can be a cause of failure of the compressor.

For example, Japanese Patent Application Laid-Open No. 62-66065 discloses a refrigeration cycle apparatus capable of preventing liquid from returning to the compressor. In this refrigeration cycle apparatus, an electric coil functioning as a heater is arranged in a suction passage connected to the suction port of the compressor, and temperature sensors are arranged at both ends of the electric coil. The wetness of the refrigerant gas in the suction pipe is determined from changes in the detected value of the temperature sensor while the electric coil is in operation, and the degree of opening of the expansion valve is adjusted according to the wetness of the refrigerant gas in the suction pipe. Liquid return to the compressor is prevented by stopping the compressor.

JP-A-62-66065

In the above Japanese Patent Application Laid-Open No. 62-66065, control for preventing liquid return is performed based on the result of estimating the degree of wetness in the suction passage from the temperature difference between both ends of the electric coil during operation of the electric coil.

However, the relationship between the temperature difference between both ends of the electric coil and the wetness in the suction channel can change depending on the refrigerant flow rate (the amount of refrigerant flowing per unit time) in the suction channel. That is, even if the wetness in the suction channel is the same, if the refrigerant flow rate in the suction channel is different, the temperature difference between both ends of the electric coil will also have different values, and the wetness in the suction channel will be different. There is a concern that the estimation accuracy will decrease. However, the aforementioned Japanese Patent Application Laid-Open No. 62-66065 makes no mention of such problems and countermeasures against them.

Further, in the above-mentioned Japanese Patent Application Laid-Open No. 62-66065, since control is performed only to prevent the liquid return, the user does not notice that the liquid return has occurred and performs maintenance of the refrigeration cycle apparatus. measures cannot be taken.

The present disclosure has been made to solve the above-described problems, and its object is to accurately estimate the liquid return to the compressor and warn the user.

A refrigeration cycle system according to the present disclosure includes a refrigerant circuit including a compressor and a suction flow path connected to a suction port of the compressor, a heater provided in the suction flow path, a warning device that outputs a warning to a user, a controller for controlling the heater and the warning device. The control device calculates a required amount of heating using the rotation speed of the compressor, operates the heater so that the amount of heating by the heater becomes the required amount of heating, and, while the heater is in operation, the upstream side of the heater in the suction flow path. a warning device to output a warning when a temperature difference between a first portion arranged on the lower side of the heater and a second portion arranged on the downstream side of the heater is less than a reference value.

According to the present disclosure, it is possible to accurately estimate liquid return to the compressor and warn the user.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure (part 1) which shows an example of the whole structure of a refrigerating-cycle apparatus typically. 10 is a flowchart (part 1) showing an example of a processing procedure of the control device; It is a figure which shows an example of the corresponding relationship between the rotational speed of a compressor, and the required heating amount of a heater. FIG. 5 is a diagram showing a correspondence relationship between inlet dryness and sensor temperature difference ΔT; It is a figure (the 2) which shows an example of the whole structure of a refrigerating-cycle apparatus typically. 2 is a flowchart (part 2) showing an example of a processing procedure of a control device;

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. A plurality of embodiments will be described below, but appropriate combinations of the configurations described in the respective embodiments have been planned since the filing of the application. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

Embodiment 1.
[Description of configuration]
FIG. 1 is a diagram schematically showing an example of the overall configuration of a refrigeration cycle apparatus 1 according to Embodiment 1. As shown in FIG. The refrigeration cycle device 1 includes a refrigerant circuit RC, temperature sensors 10 and 20, a heater 30, a power supply 40, a warning device 120, and a control device 100.

The refrigerant circuit RC connects the compressor 2, the flow switching device 3, the first heat exchanger 4, the pressure reducing device 5, the second heat exchanger 6, and the receiver 7, thereby circulating the refrigerant. It constitutes a circulating flow path. Refrigerant accompanied by a phase change, such as carbon dioxide and R410A, circulates inside the refrigerant circuit RC.

The compressor 2 sucks the low-pressure refrigerant, compresses it, and discharges it as a high-pressure refrigerant. The compressor 2 discharges refrigerant at a flow rate corresponding to the rotation speed. The compressor 2 is, for example, an inverter compressor with a variable rotation speed (discharge flow rate). The refrigerant flow rate circulating in the refrigeration cycle device 1 is controlled by adjusting the rotation speed (discharge flow rate) of the compressor 2 .

The 1st heat exchanger 4 is a heat exchanger which has a channel through which a refrigerant flows. In the first heat exchanger 4, heat is exchanged between the refrigerant flowing through the flow path and the air outside the flow path.

The decompression device 5 decompresses the high-pressure refrigerant. As the decompression device 5, a device having a valve body capable of adjusting the degree of opening, for example, an electronically controlled expansion valve can be used.

The 2nd heat exchanger 6 is a heat exchanger which has a channel through which a refrigerant flows. In the second heat exchanger 6, heat is exchanged between the refrigerant flowing through the flow path and the air outside the flow path.

The receiver 7 is a container that stores refrigerant therein, and is installed on the suction side of the compressor 2 . An upper portion of the receiver 7 is provided with a suction port to which a pipe for inflow of refrigerant is connected, and a discharge port to which a pipe for outflow of refrigerant is connected. The refrigerant is separated into gas and liquid within the receiver 7 . The gas-liquid separated gas refrigerant is sucked into the compressor 2 .

The refrigeration cycle device 1 can be operated by switching between the cooling mode and the heating mode by switching the state of the flow path switching device 3 .

The flow switching device 3 is provided on the discharge side of the compressor 2 . The flow switching device 3 is configured to switch the refrigerant discharged from the compressor 2 to either the first heat exchanger 4 or the second heat exchanger 6 to flow the refrigerant. The flow switching device 3 connects the discharge side of the compressor 2 to the first heat exchanger 4 and connects the suction side of the compressor 2 to the second heat exchanger 6 to switch the refrigerant discharged from the compressor 2. to the first heat exchanger 4, and the discharge side of the compressor 2 is connected to the second heat exchanger 6 and the suction side of the compressor 2 is connected to the first heat exchanger 4. , and a “second state” in which the refrigerant discharged from the compressor 2 flows to the second heat exchanger 6 . Note that FIG. 1 shows an example in which the flow path switching device 3 is controlled to the "first state".

In the cooling mode, the flow switching device 3 is in the first state, and the discharge side of the compressor 2 is connected to the first heat exchanger 4 . In cooling mode, the first heat exchanger 4 functions as a condenser and the second heat exchanger 6 functions as an evaporator. In the cooling mode, the high-temperature, high-pressure refrigerant discharged from the compressor 2 flows into the first heat exchanger 4 via the flow switching device 3 . The high-temperature, high-pressure refrigerant exchanges heat with the outside air in the first heat exchanger 4 and flows out of the first heat exchanger 4 after being lowered in temperature. The refrigerant that has flowed out of the first heat exchanger 4 is decompressed by the decompression device 5 and flows into the second heat exchanger 6 as a low-temperature, low-pressure refrigerant. The low-temperature, low-pressure refrigerant exchanges heat with the outside air in the second heat exchanger 6 , rises in temperature, and flows out of the second heat exchanger 6 . The refrigerant that has flowed out of the second heat exchanger 6 flows into the receiver 7 via the flow switching device 3 and is separated into gas and liquid within the receiver 7 . Gas refrigerant in the receiver 7 is sucked into the compressor 2 .

In the heating mode, the flow switching device 3 is in the second state, and the discharge side of the compressor 2 is connected to the second heat exchanger 6 . In heating mode, the first heat exchanger 4 functions as an evaporator and the second heat exchanger 6 functions as a condenser. In the heating mode, the high-temperature, high-pressure refrigerant discharged from the compressor 2 flows into the second heat exchanger 6 via the flow switching device 3 . The high-temperature, high-pressure refrigerant exchanges heat with water flowing in the outside air in the second heat exchanger 6 and flows out of the second heat exchanger 6 after being lowered in temperature. The refrigerant that has flowed out of the second heat exchanger 6 is decompressed by the decompression device 5 and flows into the first heat exchanger 4 as a low-temperature, low-pressure refrigerant. The low-temperature, low-pressure refrigerant exchanges heat with the outside air in the first heat exchanger 4 , rises in temperature, and flows out of the first heat exchanger 4 . The refrigerant that has flowed out of the first heat exchanger 4 flows into the receiver 7 via the flow switching device 3 and is separated into gas and liquid within the receiver 7 . Gas refrigerant in the receiver 7 is sucked into the compressor 2 .

A discharge port of the receiver 7 and a suction port of the compressor 2 are connected by a suction pipe (suction flow path) P1. Refrigerant discharged from the receiver 7 is sucked into the compressor 2 through the suction pipe P1.

A heater 30 is provided in the intake pipe P1. The heater 30 generates heat by electric power supplied from the power supply 40 to heat the intake pipe P1. The amount of heating by the heater 30 (the amount of power supplied from the power supply 40 to the heater 30 ) is adjusted by the control device 100 controlling the power supply 40 .

A temperature sensor (first temperature sensor) 10 is provided in a portion upstream of the heater 30 in the suction pipe P1. A second temperature sensor (second temperature sensor) 20 is provided in a portion downstream of the heater 30 in the suction pipe P1. The detection results of temperature sensors 10 and 20 are transmitted to control device 100 .

Warning device 120 outputs a warning to the user using a warning lamp, a display, a speaker, or the like. The content of the warning output by warning device 120 is controlled in accordance with a command from control device 100 .

The control device 100 includes a CPU (Central Processing Unit), a memory, and an input/output port for inputting/outputting various signals. The control device 100 controls each device of the refrigeration cycle device 1 (compressor 2, channel switching device 3, decompression device 5, heater 30, warning device 120, etc.). Note that the control performed by the control device 100 is not limited to processing by software, and processing by dedicated hardware (electronic circuit) is also possible.

[Estimation of Liquid Return to Compressor and Warning to User]
In the refrigerating cycle device 1, a receiver 7 is provided upstream of the suction pipe P1 of the compressor 2 for performing gas-liquid separation of the refrigerant. Then, during normal operation, the gas refrigerant in the receiver 7 is sucked into the compressor 2 through the suction pipe P1.

However, for example, in a situation where the receiver 7 is fully charged with liquid refrigerant, the liquid refrigerant flows out from the receiver 7 into the suction pipe P1, and the liquid refrigerant sucked into the compressor 2 becomes excessive, causing liquid return. obtain.

When the liquid returns, the lubricating oil in the sliding portions of the compressor 2 is diluted, and this may prevent the sliding portions of the compressor 2 from being properly lubricated. Therefore, liquid return may cause the compressor 2 to malfunction. If the user does not notice the occurrence of such liquid return, the user cannot take measures such as maintenance of the refrigeration cycle apparatus 1 .

Therefore, the refrigerating cycle apparatus 1 according to the first embodiment includes the above-described heater 30 and temperature sensor 10 as devices for detecting (estimating) the liquid return to the compressor 2 and prompting the user to perform maintenance. 20 is provided in the suction pipe P1 of the compressor 2, and a warning device 120 for outputting a warning to the user is provided.

If there is no liquid refrigerant in the suction pipe P1 while the heater 30 is in operation, the heat generated by the heater 30 is transmitted to the gas refrigerant in the suction pipe P1, and the temperature downstream of the heater 30 increases. The temperature difference between the heater upstream portion (first portion) arranged on the upstream side of the heater 30 and the heater downstream portion (second portion) arranged on the downstream side of the heater 30 (hereinafter referred to as "heater front-back temperature difference ) becomes relatively large. On the other hand, when the liquid refrigerant is present in the suction pipe P1 while the heater 30 is in operation, part of the heat generated by the heater 30 is transmitted not only to the gas refrigerant but also to the liquid refrigerant. Since the temperature rise on the downstream side of 30 is suppressed, the temperature difference before and after the heater becomes small.

In view of this point, the control device 100 according to the first embodiment is configured so that the detected value of the temperature sensor 10 provided at the upstream portion of the heater and the detected value of the temperature sensor 20 provided at the downstream portion of the heater during operation of the heater 30 The difference (hereinafter also referred to as "sensor temperature difference ΔT") is calculated as the temperature difference before and after the heater, and when the sensor temperature difference ΔT is less than the reference value Tref, it is estimated that liquid return has occurred, and the warning device 120 to output a warning. Note that the reference value Tref is a fixed value pre-stored in the memory of the control device 100 .

Here, the temperature difference before and after the heater (sensor temperature difference ΔT) can change depending on not only the amount of heat by the heater 30 but also the flow rate of the refrigerant in the suction pipe P1. Therefore, if the amount of heating by the heater 30 is assumed to be a fixed value, the sensor temperature difference ΔT will fluctuate according to the refrigerant flow rate, and the liquid return estimated by comparing the sensor temperature difference ΔT and the reference value Tref (fixed value) can reduce the estimation accuracy of

Therefore, in the control device 100 according to the present embodiment, when the heater 30 is operated for estimating liquid return, the temperature difference before and after the heater (sensor temperature difference ΔT) does not fluctuate according to the refrigerant flow rate in the suction pipe P1. , the amount of heating by the heater 30 is adjusted using the rotation speed of the compressor 2 . As a result, it is possible to accurately estimate the liquid return regardless of the refrigerant flow rate.

FIG. 2 is a flowchart showing an example of a processing procedure executed by control device 100 when estimating liquid return and warning the user. This flowchart is repeatedly executed each time a predetermined condition is satisfied (for example, every predetermined cycle) while the compressor 2 is in operation.

First, the control device 100 calculates the required heating amount of the heater 30 using the rotation speed of the compressor 2 (step S10). As described above, this step is performed to adjust the required heating amount of the heater 30 so that the temperature difference before and after the heater (sensor temperature difference ΔT) does not fluctuate according to the refrigerant flow rate.

FIG. 3 is a diagram showing an example of the correspondence relationship between the rotation speed of the compressor 2 and the required heating amount of the heater 30. As shown in FIG. As shown in FIG. 3, the higher the rotational speed of the compressor 2 is, the larger the required heating amount of the heater 30 is adjusted. A map defining the correspondence relationship as shown in FIG. 3 is stored in advance in the memory of the control device 100, and the control device 100 refers to the map to calculate the required heating amount corresponding to the rotational speed of the compressor 2. do.

Returning to FIG. 2, the control device 100 operates the heater 30 so that the heating amount by the heater 30 becomes the required heating amount calculated in step S10 (step S12).

Next, while the heater 30 is in operation, the controller 100 calculates the sensor temperature difference ΔT (difference between the detected value of the temperature sensor 10 and the detected value of the temperature sensor 20) as the temperature difference before and after the heater (step S14).

Next, control device 100 reads reference value Tref from the memory (step S16), and determines whether sensor temperature difference ΔT calculated in step S14 is less than reference value Tref (step S18). If the sensor temperature difference ΔT is not less than the reference value Tref (NO in step S18), it is estimated that almost no liquid refrigerant is contained in the suction pipe P1 and liquid return does not occur. Skip the rest of the process and move to return.

On the other hand, if the sensor temperature difference ΔT is less than the reference value Tref (YES in step S18), the control device 100 presumes that a large amount of liquid refrigerant is contained in the suction pipe P1 and liquid return is occurring. The "liquid back operation time" is counted up (step S20). The "liquid back operation time" is an index representing the cumulative time of operation with liquid return occurring since the last maintenance. The liquid back operation time is stored, for example, in the memory of control device 100 .

The control device 100 determines whether or not the liquid back operation time has exceeded the reference time (step S22). If the liquid back operation time has not exceeded the reference time (NO in step S22), control device 100 skips the subsequent processing and shifts the processing to RETURN.

If the liquid back operation time has exceeded the reference time (YES in step S22), the control device 100 causes the warning device 120 to output a warning indicating that the liquid back operation time has exceeded the reference time (step S24). The warning output in step S<b>24 may include a message prompting the user to receive maintenance of the refrigeration cycle apparatus 1 .

Further, the history of the liquid back operation time may be maintained even after the warning in step S24 so that the manufacturer or contractor who maintains the refrigerating cycle device 1 can diagnose the refrigerating cycle device 1. However, when the compressor 2 is replaced with a new one during maintenance, it is desirable to reset the liquid back operation time.

As described above, when the sensor temperature difference ΔT during operation of the heater 30 is less than the reference value Tref, the control device 100 according to the present embodiment presumes that the liquid has returned, and the warning device 120 output a warning. At this time, the amount of heating by the heater 30 is adjusted using the rotation speed of the compressor 2 so that the sensor temperature difference ΔT does not fluctuate according to the refrigerant flow rate. As a result, it is possible to accurately estimate the liquid return regardless of the refrigerant flow rate.

Furthermore, the control device 100 according to the present embodiment controls the liquid backflow operation time, which is the cumulative time during which the sensor temperature difference ΔT is determined to be less than the reference value Tref, exceeds the reference time. The warning device 120 is caused to output a warning indicating that the driving time has exceeded the reference time. Upon receiving this warning, the user can prevent sudden failure of the compressor 2 by taking measures such as inspection and maintenance of the refrigeration cycle device 1 at an early stage.

Modification 1.
In the first embodiment described above, in determining whether or not the temperature difference before and after the heater is less than the reference value Tref, the sensor temperature difference ΔT is calculated as the temperature difference between before and after the heater, and the sensor temperature difference ΔT is used as the reference value Tref. are comparing. However, the method for determining whether or not the temperature difference before and after the heater is less than the reference value Tref is not limited to this method.

FIG. 4 is a diagram showing a correspondence relationship between the dryness (inlet dryness) of the inlet portion of the heater 30 in the suction pipe P1 and the temperature difference before and after the heater (sensor temperature difference ΔT). As can be understood from FIG. 4, the fact that the inlet dryness is less than the threshold value xin is equivalent to the fact that the temperature difference before and after the heater (sensor temperature difference ΔT) is less than the reference value Tref. In view of this point, for example, the inlet enthalpy of the heater upstream portion is calculated as the inlet dryness from the temperature and pressure of the outlet portion of the heater 30 in the suction pipe P1, the amount of heating by the heater 30, the refrigerant flow rate, etc., and the inlet enthalpy is the threshold. If the difference is less than the value corresponding to the value xin, it may be determined that the temperature difference across the heater is less than the reference value Tref.

Embodiment 2.
FIG. 5 is a diagram schematically showing an example of the overall configuration of a refrigeration cycle apparatus 1A according to Embodiment 2. As shown in FIG. A refrigerating cycle apparatus 1A is constructed by adding a sub-pipe P2 branching from the suction pipe P1 to the refrigerating cycle apparatus 1 shown in FIG. be. Other configurations and operations of refrigeration cycle device 1A are the same as those of refrigeration cycle device 1 shown in FIG. 1 described above, and therefore detailed description thereof will not be repeated.

The secondary pipe P2 is formed to branch from the suction pipe P1 in the vicinity of the connection with the receiver 7 in the suction pipe P1 and join the suction pipe P1 in the vicinity of the connection with the compressor 2 in the suction pipe P1. The passage cross section of the sub pipe P2 is smaller than the passage cross section of the suction pipe (main pipe) P1. The heater 30 and the temperature sensors 10, 20 are arranged in the secondary pipe P2 instead of the suction pipe P1.

The control device 100 according to the second embodiment operates the heater 30 arranged in the secondary pipe P2 branching from the suction pipe P1 to execute the liquid return estimation process (the process shown in the flowchart of FIG. 2 described above). Therefore, compared to the refrigeration cycle apparatus 1 according to the above-described first embodiment, which operates the heater 30 arranged in the suction pipe P1 that does not branch to the secondary pipe P2, the heater 30 becomes a heating target in the liquid return estimation process. The amount of refrigerant can be reduced. As a result, the power consumption of the heater 30 required for the process of estimating the liquid return can be reduced.

Furthermore, in Embodiment 2, the flow passage cross section of the sub pipe P2 is smaller than the flow passage cross section of the suction pipe (main pipe) P1. Therefore, the amount of refrigerant to be heated by the heater 30 can be further reduced compared to the case where the passage cross section of the sub pipe P2 is equal to or larger than the passage cross section of the suction pipe (main pipe) P1. Thereby, the power consumption of the heater 30 can be further reduced.

Note that the channel cross-section of the secondary pipe P2 is not necessarily limited to being smaller than the channel cross-section of the suction pipe P1. For example, the channel cross-section of the secondary pipe P2 may be the same as the channel cross-section of the suction pipe P1.

Embodiment 3.
The control device 100 according to Embodiment 1 described above always operates the heater 30 while the compressor 2 is operating in the flow chart of FIG. 2 . On the other hand, in the control device 100 according to the third embodiment, when the compressor 2 is in operation and the temperature of the refrigerant discharged from the compressor 2 (hereinafter also referred to as "discharge temperature of the compressor 2") is If the temperature is lower than the reference temperature, the heater 30 is activated.

In the flowchart of FIG. 2 described above, a warning is output when the accumulated time (liquid back operation time) during which the sensor temperature difference ΔT is determined to be less than the reference value Tref exceeds the reference time. In contrast, the control device 100 according to the third embodiment outputs a warning when the sensor temperature difference ΔT is less than the reference value Tref.

FIG. 6 is a flowchart showing an example of a processing procedure executed by control device 100 according to Embodiment 3 when estimating liquid return and warning the user. In this flowchart, step S30 is added, steps S20 and S22 are deleted, and step S24 is changed to step S24a with respect to FIG. Other steps in FIG. 6 (steps with the same numbers as the steps shown in FIG. 2 above) have already been described, and detailed description thereof will not be repeated here.

The flowchart shown in FIG. 6 is also repeatedly executed each time a predetermined condition is satisfied (for example, every predetermined period) during operation of the compressor 2, similarly to the above-described FIG.

First, the control device 100 determines whether or not the discharge temperature of the compressor 2 is lower than the reference temperature (step S30). It is assumed that the discharge temperature of compressor 2 is detected, for example, by a temperature sensor (not shown) arranged on the discharge side of compressor 2 .

When the discharge temperature of the compressor 2 exceeds the reference temperature (NO in step S30), the discharge side of the compressor 2 contains a large amount of gaseous refrigerant and the liquid return is unlikely to occur. , the control device 100 skips the subsequent processing and shifts the processing to return. That is, even when the compressor 2 is operating, the heater 30 is not operated when the discharge temperature of the compressor 2 exceeds the reference temperature. Therefore, power consumption of the heater 30 can be reduced as compared with the case where the heater 30 is always operated while the compressor 2 is in operation.

On the other hand, if the discharge temperature of the compressor 2 is less than the reference temperature (YES in step S30), there is a possibility that liquid refrigerant is contained in the discharge side of the compressor 2 and liquid return has occurred. 100 executes the processing from step S10 onwards, and performs liquid return estimation processing.

Furthermore, when it is determined that the sensor temperature difference ΔT is less than the reference value Tref (YES in step S18), control device 100 causes warning device 120 to output a warning indicating that the liquid is returning (step S24a).

As described above, control device 100 according to Embodiment 3 operates heater 30 when compressor 2 is in operation and the discharge temperature of compressor 2 is lower than the reference temperature. In other words, control device 100 according to Embodiment 3 does not operate heater 30 when the discharge temperature of compressor 2 exceeds the reference temperature even during operation of compressor 2 . Therefore, power consumption of the heater 30 can be reduced as compared with the case where the heater 30 is always operated while the compressor 2 is in operation.

Further, control device 100 according to the third embodiment issues a warning indicating that liquid return is occurring when it is determined that sensor temperature difference ΔT is less than reference value Tref (YES in step S18). 120 to output. With such a warning, the user can be informed in real time how often liquid return occurs.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present disclosure is indicated by the scope of claims rather than the above description, and is intended to include all changes within the meaning and scope of equivalence to the scope of claims.

Reference Signs List 1, 1A refrigerating cycle device, 2 compressor, 3 channel switching device, 4 first heat exchanger, 5 decompression device, 6 second heat exchanger, 7 receiver, 10, 20 temperature sensor, 30 heater, 40 power supply, 100 control device, 120 warning device, P1 suction pipe, P2 secondary pipe, RC refrigerant circuit.

Claims (7)

a refrigerant circuit including a compressor and a suction passage connected to a suction port of the compressor;
a heater provided in the suction channel;
a warning device that outputs a warning to the user;
A control device that controls the heater and the warning device,
The control device is
Calculate the required heating amount using the rotation speed of the compressor,
operating the heater so that the amount of heating by the heater becomes the required amount of heating;
When the temperature difference between a first portion arranged upstream of the heater and a second portion arranged downstream of the heater in the suction passage during operation of the heater is less than a reference value A refrigeration cycle device that causes the warning device to output the warning. The refrigeration cycle apparatus according to claim 1, wherein when operating the heater, the control device operates the heater so that the amount of heating by the heater increases as the rotational speed of the compressor increases. The suction flow path includes a main flow path and a sub-flow path branched from the main flow path,
3. The refrigeration cycle apparatus according to claim 1, wherein said heater is provided in said sub-flow path. 4. The refrigeration cycle apparatus according to claim 3, wherein the secondary flow path has a flow path cross-section that is smaller than the flow path cross-section of the main flow path. When the temperature difference is less than the reference value while the heater is in operation, and when the time during which the temperature difference is less than the reference value exceeds a reference time, the controller sends the warning device to The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein said warning is output. 6. The control device according to any one of claims 1 to 5, wherein the controller operates the heater when the compressor is in operation and the temperature of the refrigerant discharged from the compressor is lower than a reference temperature. A refrigeration cycle apparatus as described. a first temperature sensor provided in the first portion;
A second temperature sensor provided in the second portion,
The control device according to any one of claims 1 to 6, wherein the controller calculates the temperature difference using the detected value of the first temperature sensor and the detected value of the second temperature sensor while the heater is in operation. A refrigeration cycle apparatus as described.

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