JP2008057875A - Refrigerating cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To save a space and to reduce cost by preventing damage of an invertor circuit caused by overheating of an invertor, and dispensing with a refrigerant circuit exclusive for cooling the invertor. <P>SOLUTION: This refrigerating cycle device is provided with the refrigerant circuit (bypass circuit) exclusive for cooling an invertor radiating portion 505 and an invertor radiating portion temperature-detecting means 520 in a main refrigerant circuit constituted by circularly connecting a compressor 10, a condenser 3, an expansion means 4 for a cooler and the cooler 5 by piping. When the invertor radiating portion temperature-detecting means 520 detects that a temperature of the invertor radiating portion 505 becomes higher than a predetermined specific value, a cooler expansion means control means 404 receiving a result of the detection by the invertor radiating portion temperature-detecting means 520 controls an expansion means 514 for cooling the invertor to increase the amount of refrigerant passing through the invertor radiating portion 505 or to inhibit the decrease of the amount of refrigerant passing through the invertor radiating portion 505, thus the overheating of the invertor circuit 3 can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus using an inverter-driven compressor.

In recent years, an increase in the number of refrigeration cycle apparatuses that perform compressor operation frequency control using an inverter is aimed at improving the partial load efficiency. Electrical loss in the rectifier circuit, inverter circuit, smoothing capacitor, and the like generated when the frequency is converted by the inverter is converted into heat. (Hereafter referred to as inverter heat generation.)
In order to dissipate the heat generated by the inverter, a heat sink or the like (hereinafter referred to as an inverter heat radiating section) is attached to the rectifier circuit, etc., and the air around the inverter is blown to the inverter heat radiating section to cool the inverter heat radiating section. It is common.
However, when the inverter output power increases, the inverter heat generation increases in proportion to the increase of the inverter output power. As a result, the amount of cooling air required increases. For this reason, in a refrigerator having a large inverter output power, a large blower fan or a large cooling air passage is required to secure a cooling air volume, which is a great restriction on the design of the refrigerator.
In order to eliminate such design restrictions, an inverter cooling method is known in which the inverter heat dissipating section 505 is cooled with a refrigerant. (For example, refer to Patent Document 1) With this method, a fan and a cooling air passage are not required, and restrictions on the design of the refrigerator can be eliminated.

Japanese Patent Laying-Open No. 2003-21406 (FIG. 1, paragraph 0019)

  However, in the conventional example shown in Patent Document 1, the control method of the expansion means provided for cooling the inverter is not clarified. For this reason, when the refrigerant temperature of the inverter radiating section is high or the refrigerant flow rate for cooling the inverter is low, the inverter radiating section becomes insufficiently cooled, and the DC rectifier circuit, smoothing capacitor, and inverter circuit may overheat. It was. Inverter circuits may be damaged if overheated.

  Further, it is necessary to provide a dedicated refrigerant circuit (hereinafter referred to as an inverter cooling circuit) for cooling the inverter.

  The present invention has been made to solve the above-described problems, and its main purpose is to prevent damage to the inverter circuit due to overheating of the inverter, and to save space by eliminating the dedicated refrigerant circuit for inverter cooling. And to reduce costs.

  A refrigeration cycle apparatus according to the present invention includes a compressor driven by an inverter and having a compression mechanism, a condenser that radiates and cools the refrigerant discharged from the compressor, and an expansion unit that decompresses and expands the refrigerant discharged from the condenser. A cooling device that evaporates the refrigerant that has come out of the expansion means is connected in an annular manner sequentially by piping, an inverter heat radiation portion that dissipates heat generated by the inverter by the refrigerant, and a temperature detection means that detects the temperature of the inverter heat radiation portion, And a control means for changing the flow rate of the refrigerant passing through the inverter heat radiating section with respect to the expansion means based on the detection result of the temperature detection means.

  According to this invention, the control means causes the expansion means to adjust the flow rate of the refrigerant passing through the inverter heat radiating portion based on the temperature of the inverter heat radiating portion detected by the temperature detecting means, thereby preventing overheating of the inverter circuit. be able to.

Embodiment 1 FIG.
FIG. 1 shows an internal circuit of an inverter 500 used in the first embodiment. The alternating current supplied to the inverter 500 from the alternating current power source 509 is converted into direct current by the rectifier circuit 501. In order to further stabilize the direct current, a high-frequency alternating current component is removed by the direct current reactor 504, and a ripple current generated when the direct current is converted into an alternating current having a set frequency is absorbed by the smoothing capacitor 502. The output of the smoothing capacitor is converted into alternating current by the inverter circuit 503, and the rotational speed of the compressor motor MC 10Y is controlled.
In addition, since the inverter circuit 503 and the smoothing capacitor 502 have small resistance values, a large inrush current may occur when the power is turned on, and the circuit may be damaged. For this reason, when the power supply of the inverter is OFF, the contactor 507 is turned OFF, and when the power is turned on, a current flows through the inverter circuit 503 via the resistor 508 installed in parallel. Since the resistance of the entire inverter is increased by the resistor 508, the inrush current is reduced and circuit damage can be prevented. Then, after a certain period of time has elapsed, that is, after the inrush current is completely eliminated and the circuit is stabilized, the contactor 507 is turned on to reduce the resistance value of the entire circuit.

In the first embodiment, in order to prevent circuit damage due to insufficient cooling of the inverter heat radiation portion 505, as shown in FIG. 2, the compressor 10, the condenser 3, the cooler expansion means 4, and the cooler 5 are sequentially piped. A dedicated refrigerant circuit (bypass circuit) for cooling the inverter heat radiating section 505 and the inverter heat radiating section temperature detecting means 520 are provided in the main refrigerant circuit configured to be connected in an annular shape with the temperature of the inverter heat radiating section 505 in advance. When the inverter heat radiating portion temperature detecting means 520 detects that the temperature exceeds the predetermined value, the cooler expansion means control means 404 that has received the detection result of the inverter heat radiating portion temperature detecting means 520 causes the inverter heat radiating portion 505 to Inverse so as to increase the amount of refrigerant passing through or to inhibit the amount of refrigerant passing through the inverter heat radiation part 505 from decreasing. And it controls the cooling expansion device 514, to prevent the inverter circuit 3 to overheat.
Thereby, in this Embodiment 1, since the temperature of the inverter thermal radiation part 505 is maintained below a fixed value, the circuit damage resulting from circuit overheating can be prevented.
The smoothing capacitor 502 has a characteristic that the ripple current that can be absorbed increases as the ambient temperature decreases. For this reason, in the first embodiment, by controlling the temperature of the inverter heat radiating unit 505 to be lower than that in a normal case, there is an advantage that a smoothing capacitor having a smaller capacity than that in a normal case can be selected.
The cooler expansion means 4 constitutes an expansion means, the cooler expansion means control means 404 constitutes a control means, and the inverter heat radiation part temperature detection means 520 constitutes a temperature detection means.

Embodiment 2. FIG.
In the first embodiment, a dedicated refrigerant circuit for cooling the inverter heat radiating unit 505 is provided to cool the inverter. However, in the second embodiment, as shown in the refrigerant circuit in FIG. Is provided in the middle of the path of the compressor suction pipe (the pipe connecting the cooler 5 and the compressor 10 in FIG. 3), and the inverter heat radiation portion 505 is cooled by the refrigerant guided from the outlet of the cooler 5. In this case, when the inverter heat radiating portion temperature detecting means 520 detects that the temperature of the inverter heat radiating portion 505 is equal to or higher than a predetermined value, the cooler that has received the detection result of the inverter heat radiating portion temperature detecting means 520. The expansion means control means 404 controls the cooler expansion means 4 so as to increase the amount of refrigerant passing through the inverter heat radiating portion 505 or prohibit the amount of refrigerant passing through the inverter heat radiating portion 505 from decreasing. Prevent damage from overheating of the circuit.

  In addition, coating is performed using a resin or the like on the surface of a part that may cause a short circuit, such as the charging exposed portion, the rectifier circuit 501, and the inverter circuit 503. When the amount of refrigerant passing through the inverter heat radiation part 505 is too large, the inverter heat radiation part 505 is excessively cooled, the surface temperatures of the rectifier circuit 501, the smoothing capacitor 502, and the inverter circuit 503 are lowered, and condensation is formed on the charge exposed part and the circuit surface. May occur. If dew condensation occurs on the exposed charging part or on the circuit surface, a short circuit may occur and the inverter may be damaged, but this can be prevented by coating.

Further, when the temperature of the inverter heat dissipating section 505 falls below a predetermined value set in advance, the cooler expansion means control means 404 controls the inverter cooling expansion means 514 or the cooler expansion valve 4 so as to reduce the suction refrigerant flow rate. Then, the amount of refrigerant passing through the inverter heat radiating section 505 is reduced, or the amount of refrigerant passing through the inverter heat radiating section 505 is prohibited from increasing, thereby preventing the condensation from occurring on the charge exposed portion and the circuit surface. May be performed.
Thereby, since the temperature of the inverter heat radiation part 505 is maintained at a certain value or more, a short circuit due to condensation can be prevented.

Embodiment 3 FIG.
In the second embodiment, the inverter heat radiating section 505 is provided in the middle of the path of the suction pipe. However, in the third embodiment, as shown in FIG. 4, the inverter 500 is stored in a fully sealed container, Heat generators such as a rectifier circuit 501, a smoothing capacitor 502, and an inverter circuit 503 are arranged in the inverter 500 so as to be integrated with the compressor and so that the joint between the fully sealed container and the compressor functions as the inverter heat radiating unit 505. . And the inverter thermal radiation part 505 is cooled with the low temperature refrigerant | coolant which the compressor suck | inhaled.
FIG. 5 shows an example of the compressor according to the third embodiment. In FIG. 5, the compressor 10 includes a compressor discharge port 10a, a compressor suction port 10b, a compression mechanism 10w, a compression mechanism suction unit 10X, an electric motor 10Y, and a suction strainer 10Z that captures foreign matter, and a rectifier circuit. 501, a smoothing capacitor 502, an inverter circuit 503, an inverter heat dissipation unit 505, and an inverter 500 including an inverter control board 508.

In FIG. 5, the inverter heat radiating portion 505 is attached to the compressor suction port 10b, but the inverter heat radiating portion 505 includes the compressor mechanism suction portion 10X and is located upstream from the refrigerant flow. You may attach to either.
Further, fins may be attached to the inverter heat radiating section 505 to improve heat transfer characteristics.

  In the third embodiment, as in the first embodiment, when the temperature of the inverter heat radiating section 505 is equal to or higher than a predetermined value set in advance, the cooler expansion means control means 404 causes the amount of refrigerant passing through the inverter heat radiating section 505. Or the expansion means 4 for the cooler is controlled so as to inhibit the amount of refrigerant passing through the inverter heat dissipating section 505 from decreasing.

In addition, when the temperature of the inverter heat radiating unit 505 is equal to or lower than a predetermined value set in advance, the cooler expansion means control unit 404 controls the cooler expansion valve 4 so as to reduce the suction refrigerant flow rate, and the inverter heat radiating unit 505. The amount of refrigerant passing through the inverter may be decreased, or the amount of refrigerant passing through the inverter heat dissipating unit 505 may be prohibited to be controlled to prevent condensation from occurring on the charge exposed portion or the circuit surface.
Thereby, since the temperature of the inverter heat radiation part 505 is maintained at a certain value or more, a short circuit due to condensation can be prevented.

According to the third embodiment, first, since the inverter and the compressor are integrally configured, the inverter cooling circuit that is necessary in the refrigerant circuit of the second embodiment is unnecessary, and the refrigeration cycle apparatus is inexpensive. Has an effect.
Secondly, since the distance of the inverter output wiring is very short and it is housed in a fully sealed container, there is an effect that radiation noise is reduced.
Third, as compared with the case where the inverter is air-cooled, it is not necessary to secure an air flow path or to take measures against rainwater, so that the degree of freedom in designing the refrigeration cycle apparatus is increased and the apparatus size can be reduced. In addition, since a completely sealed container is used, there is an advantage that it is not necessary to consider intrusion of rainwater or the like.

Embodiment 4 FIG.
In the third embodiment, the temperature of the inverter heat radiating section is used to control the cooler expansion means 4, but as shown in FIG. 6, the present embodiment 4 is located downstream of the inverter heat radiating section 505, for example, The degree of superheat in the compression mechanism suction section 10x is detected by the compression mechanism suction pressure detected by the compression mechanism suction section pressure detection means 110x and the compression mechanism suction section temperature detection means 210x. The cooler expansion means 4 is controlled by the cooler expansion means control means 404 so that the degree of superheat at a position downstream of the inverter heat radiation portion 505 is constant, calculated from the compression mechanism suction temperature.
In this case, when the temperature of the inverter heat dissipating part 505 rises, the degree of superheat rises, so the cooler expansion means 4 increases the refrigerant flow rate. As a result, the refrigerant flow rate of the inverter heat radiating portion 505 increases, and the temperature rise of the inverter heat radiating portion is suppressed.
Further, when the temperature of the inverter heat dissipating part 505 is lowered, the degree of superheat is lowered, so the cooler expansion means 4 reduces the refrigerant flow rate. As a result, the refrigerant flow rate of the inverter heat radiating portion is reduced, and the temperature decrease of the inverter heat radiating portion is suppressed.
For this reason, the inverter heat radiating section temperature detecting means 520 is not required, and it is not necessary to develop a new control of the cooler expansion means 4 for controlling the temperature of the inverter heat radiating section 505, and the conventional constant superheat control is kept as it is. Can be diverted.
In the above example, the expansion unit control unit 404 for the cooler is controlled so as to adjust the refrigerant flow rate of the inverter heat radiating unit 505 based on the degree of superheat of the compression mechanism suction unit 10X, but the degree of superheat of the compressor suction port 10b is controlled. May be controlled to adjust the refrigerant flow rate of the inverter heat dissipating section 505, and the same effect is obtained by the same control as described above.

Embodiment 5. FIG.
FIG. 7 shows a refrigerant circuit diagram of the fifth embodiment. As shown in FIG. 7, in the fifth embodiment, a two-stage compressor is used as the compressor, and the inverter heat radiating section 505 is provided at the intermediate junction 10c.
Two-stage compressors often operate at a low suction pressure, in which case the cooling capacity is low. In such an operating state, when the inverter heat generation is cooled by the compressor suction refrigerant as in the third embodiment, the cooling capacity is significantly reduced. In order to solve such a problem, in the fifth embodiment, as shown in the cross-sectional view of the compressor of the fifth embodiment in FIG. 8, an inverter heat radiating portion 505 is provided at the intermediate junction 10c, and the intermediate junction 10c is provided. The inverter heat is cooled by the refrigerant flowing into the inverter.
Then, using at least one of the cooler expansion means 4 and the subcooler expansion means 34, the flow rate of the refrigerant flowing into the intermediate confluence 10c is controlled so that the temperature of the inverter heat radiating section 505 does not exceed a certain value.

  Since the refrigerant pressure at the intermediate junction 10c is higher than the refrigerant pressure at the compressor suction port 10b, the method of cooling the inverter heat generation by the refrigerant at the intermediate junction 10c is more efficient than the method of cooling the inverter heat generation by the compressor suction refrigerant. Inverter heat generation can be cooled, and the coefficient of performance of the compressor is improved.

Embodiment 6 FIG.
In the sixth embodiment, a DC brushless motor is used as the compressor motor of the refrigeration cycle apparatus according to the third embodiment, and the temperature reduction of the compressor is prevented by using inverter heat generation.
The DC brushless motor has the characteristics that the motor loss is reduced and the coefficient of performance is improved because the motor heat generation is small. However, when the refrigerant liquid back is generated in the compressor suction port 10b, since the calorific value of the electric motor 10Y is small, the liquid refrigerant may not be evaporated and may be sucked into the compressor as it is. In such a case, an abnormal high pressure is generated in the compression mechanism 10w, and the compressor may be damaged.
In the sixth embodiment, when the liquid back occurs, the liquid refrigerant can be evaporated by the heat generation of the inverter, so that the possibility of the compressor being damaged by the liquid back can be extremely reduced.

Embodiment 7 FIG.
In the rotor of the DC brushless motor used in the refrigeration cycle apparatus of the sixth embodiment, a permanent magnet is inserted into the slot and held so as not to move with an adhesive. When the temperature of the rotor becomes low (around -40 ° C.), the toughness of the permanent magnet and the holding power of the adhesive decrease. For this reason, when the temperature of the permanent magnet is operated at a low temperature (−40 ° C. or lower), it cannot withstand the centrifugal force acting on the rotor, and the rotor may be damaged. (Hereinafter, the temperature of the permanent magnet that may damage the rotor is referred to as the permanent magnet limit temperature.)

  Therefore, in the seventh embodiment, the cooler expansion means control means 404 calculates the temperature of the permanent magnet from the compressor suction refrigerant temperature or the compression mechanism suction refrigerant temperature in order to prevent the rotor from being damaged at a low temperature. When the calculated permanent magnet temperature is likely to fall below the permanent magnet limit temperature, the expansion means is controlled so as to decrease the compressor suction refrigerant flow rate or prohibit the increase of the compressor suction refrigerant flow rate.

Further, since the centrifugal force acting on the rotor is proportional to the square of the rotational speed, the permanent magnet limit temperature becomes lower as the rotational speed decreases.
Accordingly, the permanent magnet limit temperature may be determined as needed based on the compressor rotational speed, and the expansion means may be controlled so that the permanent magnet temperature does not fall below the permanent magnet limit temperature.
As described above, according to the seventh embodiment, it is possible to suppress a decrease in the toughness of the permanent magnet and the holding power of the adhesive due to a low temperature, and it is possible to prevent the rotor from being damaged.

Embodiment 8 FIG.
In the eighth embodiment, a screw type or a turbo type is used as the compression method of the compressor of the refrigeration cycle apparatus of the third embodiment. Since the compression method has much less vibration than the reciprocating type, when it is configured integrally with the compressor, the inverter is not easily damaged by vibration.

Embodiment 9 FIG.
In the third embodiment, the inverter heat radiating portion 505 is provided in the compressor suction port 10b. In the ninth embodiment, the inverter heat radiating portion 505 is attached to the gate rotor lid of the screw compressor.
FIG. 9 shows an example of the structure of a conventional single screw compressor. FIG. 10 shows a configuration diagram around the gate rotor.
In the conventional single screw compressor, since the compressor main body shell 10T absorbs heat generated by the compression mechanism 10W, the surface temperature is high, and the liquid refrigerant adhering to the inside of the compressor main body shell 10T evaporates. The machine body shell 10T is difficult to frost.
On the other hand, the gate rotor lid 10S itself does not have a heat generating portion, and the gate rotor lid 10S is coupled to the compressor body shell 10T via the packing 10U, so that it is thermally separated from the compressor body shell 10T. . For this reason, there is no heat conduction from the compressor body shell 10T. Therefore, the liquid refrigerant adhering to the inside of the gate rotor lid 10S is difficult to evaporate.
For this reason, there is a problem that the surface temperature of the gate rotor lid 10S is lower than the surface temperature of the compressor body shell 10T and tends to form frost.

Therefore, in the ninth embodiment, an inverter heat radiation portion 505 is attached instead of the gate rotor lid 10S. FIG. 11 shows an example in which an inverter heat radiation portion 505 is attached in place of the gate rotor lid 10S in the single screw compressor. FIG. 12 shows a configuration diagram around the gate rotor.
In the fifteenth embodiment, an inverter radiating portion 505 is attached instead of the gate rotor lid 10S, and a rectifier circuit 501 that is a heating element is provided on the opposite side of the inverter radiating portion 505 from the compressor gate rotor 10V side, and an inverter Since the circuit 503 is disposed and the refrigerant adhering to the inverter heat radiating section 505 is heated and evaporated by the inverter heat generation, the effect of preventing frost formation is achieved.

Embodiment 10 FIG.
In the second embodiment, the inverter heat radiating section 505 is provided in the middle of the compressor suction pipe. However, in the tenth embodiment, the inverter 500 is stored in a fully sealed container, and the fully sealed container is connected to the accumulator 600. The heat generating materials such as the rectifier circuit 501 and the inverter circuit 503 are arranged in the inverter so that the joint portion between the fully sealed container and the accumulator 600 functions as the inverter heat radiating portion 505. Then, the inverter heat radiation part 505 is cooled by the refrigerant flowing into the accumulator 600.
FIG. 13 shows an example of a refrigerant piping diagram of the tenth embodiment. FIG. 14 shows an example of the accumulator of the tenth embodiment.

The accumulator 600 according to the tenth embodiment has an effect that a dedicated inverter cooling circuit is not required since the inverter and the accumulator are first configured integrally.
Secondly, by heating the accumulator 600, the liquid refrigerant in the accumulator 600 is evaporated, and the liquid refrigerant can be prevented from staying in the accumulator 600.
Thirdly, unlike the case where the inverter is air-cooled, it is not necessary to secure an air flow path or to take measures against rainwater, so that the degree of freedom in equipment arrangement is increased and the size of the refrigeration cycle apparatus can be reduced. In addition, since a completely sealed container is used, it is not necessary to consider intrusion of rainwater or the like.

  Note that an inverter heat dissipating section 505 may be provided below the accumulator 600 where liquid refrigerant is likely to accumulate. In this case, evaporation of the liquid refrigerant can be promoted, and compressor damage due to the liquid back can be prevented.

  In order to promote heat dissipation in the inverter heat dissipation part 505, fins may be attached to the heat dissipation part.

Embodiment 11 FIG.
The inverter generates electromagnetic wave noise when converting alternating current to direct current and converting direct current to alternating current. When electromagnetic noise is generated, electronic devices around the inverter may malfunction.
Therefore, in the eleventh embodiment, in the second to tenth embodiments, the fully sealed container that houses the inverter is made of a conductive material, and the fully sealed container is grounded.
In the eleventh embodiment, since the inverter is electrostatically shielded in the fully sealed container, radiation of electromagnetic noise to the outside of the fully sealed container can be greatly reduced.

Embodiment 12 FIG.
When the inverter rectifies alternating current to direct current, harmonics flow out to the power supply side. When the spilled harmonics flow into the phase advance capacitor, there is a problem that they may be overheated and damaged.
In general, the rectifier circuit 501 of the inverter uses a 6-pulse conversion system, but the twelfth embodiment uses a 12-pulse conversion system for the rectifier circuit 501 of the inverter.
The 12-pulse converter is configured by inputting an AC power supply with the AC voltage phase shifted by 30 degrees into two 6-pulse converters and connecting the two 6-pulse converters in series or in parallel on the DC side. To do. Since the phases of the fifth and seventh harmonic currents included in the AC side voltages for the two six-pulse converters differ by 180 degrees, they are canceled on the power supply side.
As a result, there is an effect of reducing the amount of harmonics flowing out to the power supply side. In particular, the effect is great in a compressor using a large-capacity electric motor, in which the outflow amount of the power supply harmonics is large and the reduction of the harmonic outflow amount is often strongly demanded.
As a method for shifting the phase of the AC voltage by 30 degrees, a method of combining a Δ-Δ transformer and a Δ-Y transformer is known.

Embodiment 13 FIG.
In Embodiments 1 to 12, power recovery may be performed by using an expander as the expansion means. In this case, there is an effect that the coefficient of performance is improved by reducing the electric input by the amount of power recovery. This is particularly effective when high density carbon dioxide is used as the refrigerant.
Further, a bypass circuit in which a part of the refrigerant does not flow through the expander may be provided in the refrigerant circuit. In this case, by providing a bypass circuit, it is possible to operate with different mass flow rates of the refrigerant of the compressor and the expander, and when the operating conditions change, such as when the low pressure decreases, the coefficient of performance is improved. .
Moreover, you may generate electric power using the motive power collect | recovered with the expander. Moreover, you may drive refrigeration apparatus main body apparatuses, such as a compressor, a fan, a pump, a control circuit, and an inverter, and auxiliary machinery using the electric power generated by the expander.
In the method of generating power by the expander, the compressor and the expander can be installed in different locations, and a conventionally used compressor can be used, and a dedicated fluid in which the compressor and the expander are integrated There is an effect that a machine becomes unnecessary.

Embodiment 14 FIG.
In the first to twelfth embodiments, the compressor suction pressure may be recovered using an ejector as the expansion means.
In this case, as the compressor suction pressure increases, the cooling capacity is improved and the coefficient of performance is improved. This is particularly effective when the compressor suction pressure is low.

It is an internal circuit diagram of the inverter in Embodiment 1 of this invention. It is a block diagram of the refrigeration cycle apparatus in Embodiment 1 of this invention. It is a block diagram of the refrigeration cycle apparatus in Embodiment 2 of this invention. It is a block diagram of the refrigerating-cycle apparatus in Embodiment 3 of this invention. It is a block diagram of the compressor in Embodiment 3 of this invention. It is a block diagram of the refrigerating-cycle apparatus in Embodiment 4 of this invention. It is a block diagram of the refrigeration cycle apparatus in Embodiment 5 of this invention. It is a block diagram of the compressor in Embodiment 5 of this invention. It is a structural diagram of a conventional single screw compressor. It is a block diagram around the gate rotor of a conventional single screw compressor. It is a block diagram of the single screw type compressor in Embodiment 9 of this invention. It is a block diagram around the gate rotor of the single screw type compressor in Embodiment 9 of this invention. It is a block diagram of the refrigeration cycle apparatus in Embodiment 10 of this invention. It is a block diagram of the accumulator in Embodiment 10 of this invention.

Explanation of symbols

3 condenser, 4 expansion means for cooler, 5 cooler, 5a cooler outlet, 5b cooler inlet, 10 compressor, 10a compressor discharge port, 10b compressor suction port, 10c compressor intermediate junction, 10S gate rotor Lid, 10T compressor body shell, 10U packing, 10V compressor gate rotor, 10W compression mechanism, 10X compression mechanism suction part, 10XA low stage compression mechanism, 10XB high stage compression mechanism, 10Y motor, 10Z suction strainer, 34 Expansion unit for cooler, 35 Supercooler, 110b Compressor suction pressure detection unit, 110x Compression mechanism suction pressure detection unit, 210b Compressor suction temperature detection unit, 210x Compressor suction temperature detection unit, 310b Compressor suction superheat degree calculation unit 310x compression mechanism suction superheat degree calculation unit, 404 expansion unit control means for cooler, 405 expansion for supercooler Stage control means, 500 inverter, 501 rectifier circuit, 502 smoothing capacitor, 503 inverter circuit, 504 DC reactor, 505 inverter heat radiation part, 506 resistance, 507 contactor, 508 inverter control board, 509 AC power supply, 514 expansion means for cooling inverter, 520 Inverter heat radiation part temperature detection means, 600 accumulator, 600a accumulator outlet, 600b accumulator inlet, 601 accumulator outlet piping, 602 accumulator inlet piping.

Claims (20)

A compressor driven by an inverter and having a compression mechanism, a condenser that radiates and cools the refrigerant discharged from the compressor, an expansion means that decompresses and expands the refrigerant discharged from the condenser, and an output from the expansion means In the refrigeration cycle apparatus formed by sequentially connecting the cooler for evaporating the refrigerant in a ring shape by piping,
An inverter heat dissipating part that dissipates heat generated by the inverter by the refrigerant;
Temperature detection means for detecting the temperature of the inverter heat radiation part;
Control means for adjusting the flow rate of the refrigerant passing through the inverter heat radiating section with respect to the expansion means based on the detection result of the temperature detection means;
A refrigeration cycle apparatus comprising:   When the detection result of the temperature detection unit is equal to or higher than a predetermined value, the control unit increases the flow rate of refrigerant that passes through the inverter heat dissipation unit with respect to the expansion unit, or passes through the inverter heat dissipation unit. The refrigeration cycle apparatus according to claim 1, wherein at least one of prohibiting a decrease in the refrigerant flow rate is performed.   When the detection result of the temperature detection means is equal to or less than a predetermined value set in advance, the control means reduces the flow rate of refrigerant that passes through the inverter heat dissipation part relative to the expansion means, or passes through the inverter heat dissipation part. 2. The refrigeration cycle apparatus according to claim 1, wherein at least one of prohibiting an increase in refrigerant flow rate is performed.   The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the inverter heat dissipating section is provided in the middle of the suction pipe of the compressor, and cools the inverter heat generation with a compressor suction refrigerant.   The inverter is stored in a fully sealed container, the fully sealed container is integrated with the compressor, and the inverter heat dissipating part is provided upstream of the compressor compression mechanism suction part or the compression mechanism suction part. The refrigeration cycle apparatus according to any one of claims 1 to 3. With an accumulator installed in the middle of the compressor suction pipe path,
4. The inverter is housed in a fully sealed container, the fully sealed container is formed integrally with the accumulator, and the inverter heat radiation portion is formed at the boundary between the fully sealed container and the accumulator. The refrigeration cycle apparatus according to any one of the above. A compressor suction temperature detection means for detecting the temperature of the compressor suction port instead of the temperature detection means,
Furthermore, a compressor suction pressure detecting means for detecting the pressure of the compressor suction port is provided,
The inverter heat dissipating part is installed upstream including the compressor suction port,
The control means calculates the degree of superheat of the compressor suction port based on the detection result of the compressor suction temperature detection means and the detection result of the compressor suction pressure detection means, and the degree of superheat of the compressor suction port is calculated. 6. The refrigeration cycle apparatus according to claim 5, wherein the expansion means is controlled to be constant. A compression mechanism suction temperature detection means for detecting the temperature of the compression mechanism suction section instead of the temperature detection means;
Furthermore, a compression mechanism suction pressure detection means for detecting the pressure of the compression mechanism suction part is provided,
The inverter heat dissipating part is attached upstream including the compression mechanism suction part,
The control means calculates the degree of superheat of the compression mechanism suction portion based on the detection result of the compression mechanism suction temperature detection means and the detection result of the compression mechanism suction pressure detection means, and the superheat degree is constant so that the degree of superheat is constant. 6. The refrigeration cycle apparatus according to claim 5, wherein the expansion means is controlled.   The refrigeration cycle apparatus according to claim 7 or 8, wherein a DC brushless type electric motor is used as an electric motor of the compressor.   The control means calculates the temperature of the permanent magnet of the DC brushless motor from the detection result of the compressor suction temperature detection means or the detection result of the compression mechanism suction temperature detection means, and the calculated temperature of the permanent magnet is preset. The expansion means is controlled to perform at least one of decreasing the compressor suction refrigerant flow rate or preventing the compressor suction refrigerant flow rate from increasing when the permanent magnet limit temperature is reached. The refrigeration cycle apparatus according to claim 9.   The refrigeration cycle apparatus according to claim 10, wherein the control means determines the permanent magnet limit temperature as needed according to the rotation speed of the compressor.   The refrigeration cycle apparatus according to any one of claims 5 to 11, wherein the fully sealed container is made of a conductive material, and the fully sealed container is grounded.   The refrigeration cycle apparatus according to any one of claims 1 to 12, wherein at least one of a charge exposed portion or a substrate surface of the inverter is coated.   The refrigeration cycle apparatus according to any one of claims 1 to 13, wherein a screw type is used for the compression mechanism.   The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein when the compressor includes a gate rotor lid, the inverter heat dissipating unit is attached instead of the gate rotor lid.   The refrigeration cycle apparatus according to any one of claims 1 to 15, wherein a turbo type is used for the compression mechanism.   The refrigeration cycle apparatus according to any one of claims 1 to 16, wherein a two-stage compression mechanism is used as the compression mechanism.   The refrigeration cycle apparatus according to any one of claims 1 to 17, wherein a 12-pulse conversion system is used for a DC rectifier circuit of the inverter.   The refrigeration cycle apparatus according to any one of claims 1 to 18, wherein power is recovered by using an expander as the expansion means. The refrigeration cycle apparatus according to claim 19, wherein power is generated using power recovered by the expander.

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