JP4985585B2 - Refrigeration cycle equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress leakage of a refrigerant from an indoor portion and a pressure difference between forward and backward sides of a cut-off device. <P>SOLUTION: The refrigerating cycle device 1 has a leakage suppressing device 70 arranged between the indoor portion including an evaporator 40 and an outdoor portion including an accumulator 60 etc. The leakage suppressing device 70 is provided with a solenoid valve 80, one-way valve 90 and bypass 81 as the cut-off device. When the operation of the refrigerating cycle device 1 is stopped, the cut-off device is blocked. The bypass 81 allows a refrigerant flow at a minute flow rate between the outdoor portion and the indoor portion even when the cut-off device is in the blocked state. As a result, the bypass 81 avoids generation of an excessive pressure difference between the forward and backward sides of the solenoid valve 80. Even when the refrigerant is leaked from the indoor portion, the bypass 81 suppresses the leaked flow rate. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a refrigeration cycle apparatus.

  Conventionally, a refrigeration cycle apparatus described in Patent Document 1 is known. This refrigeration cycle apparatus is called a supercritical refrigeration cycle apparatus in which the high-pressure side pressure reaches the supercritical pressure of the refrigerant. Carbon dioxide is used as the refrigerant. In this refrigeration cycle apparatus, a pressure control valve is used as a decompressor. The pressure control valve maintains the high-pressure side pressure at a predetermined pressure for obtaining high efficiency. Therefore, the pressure control valve has a pressure sensitive function.

  Patent Document 2 proposes a refrigeration cycle apparatus including a decompressor bypass in parallel with a decompressor. The pressure reducer bypass is also called a relief passage or a fixed throttle passage. The pressure reducer bypass is provided by a fixed opening throttle or a pressure sensitive valve.

  The refrigeration cycle apparatus described in Patent Document 3 shows another aspect of the decompressor. This decompressor is provided by a simple throttle valve.

Furthermore, Patent Literature 4 and Patent Literature 5 disclose a suppression device that suppresses the amount of refrigerant leakage from the indoor portion when the indoor portion of the refrigeration cycle apparatus is damaged or failed. Such a suppression device can be provided by an electromagnetic valve with an electrical control device or an automatic valve that opens and closes in response to pressure.
JP 2000-81157 A International Publication No. WO01 / 006183 Pamphlet Japanese translation of PCT publication No. 2002-520572 JP-A-9-104221 JP 2004-28461 A

  According to the conventional suppression device, the refrigerant passage of the refrigeration cycle apparatus is completely hermetically divided into a plurality of portions. For example, the refrigerant passage is partitioned into a first portion and a second portion. However, when the refrigerant passage is completely hermetically partitioned, there is a problem that the refrigerant is biased and accumulated in one of the partition portions. For example, the refrigerant may be biased depending on the state of the refrigeration cycle apparatus at the time of interruption by the suppression device. Furthermore, in the refrigeration cycle apparatus of the air conditioner, there are an outdoor part arranged outside and an indoor part arranged indoors. Due to the temperature difference between the outdoor portion and the indoor portion, the refrigerant may move to and accumulate in the low temperature side portion, for example, the outdoor portion. And the refrigerant | coolant which accumulated in a part of refrigeration cycle apparatus will become a high voltage | pressure, if the said part becomes high temperature. Such a relatively high pressure due to the uneven distribution of the refrigerant may cause various problems.

  In one aspect, the valve of the suppressor may be prevented from opening and closing. This is because an excessive differential pressure acts on the valve constituting the suppression device due to the bias of the refrigerant. For example, in the case of a solenoid valve, the solenoid valve cannot be opened and the refrigeration cycle apparatus may not be started.

  In another aspect, noise may be generated when the valve of the suppression device is opened. This is because an excessive differential pressure generated due to refrigerant bias causes a rapid refrigerant flow. For example, noise due to a water hammer phenomenon may occur.

  In yet another aspect, in order to withstand a relatively high pressure due to the uneven distribution of the refrigerant, it is necessary to set the pressure resistance performance of the parts belonging to the part higher than necessary. For example, when a low-pressure system part of the refrigeration cycle apparatus is included in a portion where a large amount of refrigerant accumulates, the low-pressure system part needs to have a high pressure resistance exceeding the pressure resistance according to the amount of refrigerant enclosed in the refrigeration cycle apparatus. .

  In view of the above problems, an object of the present invention is to provide an improved refrigeration cycle apparatus.

  In view of the above problems, the present invention suppresses the release of refrigerant when a part of the refrigeration cycle apparatus is damaged or fails, and alleviates the increase in refrigerant pressure when the refrigeration cycle apparatus is stopped. An object of the present invention is to provide an improved refrigeration cycle apparatus.

  In view of the above problems, the present invention suppresses the release of the refrigerant from the indoor portion when the indoor portion is damaged or malfunctioned, and reduces the increase in the refrigerant pressure for the outdoor portion when the indoor portion is normal. Another object is to provide a refrigeration cycle apparatus.

  In order to achieve the above object, the present invention employs the following technical means. In addition, the code | symbol in the parenthesis as described in a claim and a technical means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

In the refrigeration cycle apparatus (1, 201) comprising the compressor (10), the outdoor heat exchanger (20), the decompressor (30), and the indoor heat exchanger (40), The refrigeration cycle apparatus is provided at a position where the interior of the cycle apparatus is partitioned into a first part including the indoor heat exchanger (40) and another second part, and the communication state between the first part and the second part is determined. Is provided with a leakage suppression device (70, 270) that can be switched between a first state that can be operated and a second state that allows only a small flow rate smaller than the first state , and the leakage suppression device (70, 270) is a first state. part and a blocking device for blocking between the second portion (80,90,280,290) is provided to bypass the shut-off device, Rukoto a bypass (81,291) which permits a minute flow rate It is characterized by. According to this invention, the leakage suppression device (70, 270) allows the operation of the refrigeration cycle apparatus when in the first state, and suppresses leakage of the refrigerant when in the second state. When in the second state, the flow rate of the refrigerant from the second part to the first part is limited to a minute flow rate. For this reason, even if a refrigerant | coolant leaks from the 1st part containing an indoor heat exchanger (40), the leakage flow rate can be suppressed. Furthermore, even if the refrigerant does not leak from the first part, the refrigerant flows between the first part and the second part, so that the pressure increase in the first part or the second part is alleviated.

According to the present invention, the leakage suppression device can be realized with a relatively simple configuration.

In the invention according to claim 2 , the shut-off device (80, 90, 280, 290) is provided on the downstream side of the evaporator and the electromagnetic valve (80, 280) provided on the upstream side of the evaporator (40). The one-way valve (90, 290) is provided, and the bypass (81, 291) is provided in at least one of the electromagnetic valve and the one-way valve. The bypass can be provided only in one or both of the electromagnetic valve and the one-way valve. According to the present invention, a bypass can be easily provided using an electromagnetic valve or a one-way valve as a shut-off device.

The invention according to claim 3 is characterized in that the bypass (81) is provided in the electromagnetic valve (80) and bypasses the electromagnetic valve (80). According to the present invention, the bypass can be easily provided using the electromagnetic valve.

In the invention according to claim 4 , the electromagnetic valve (80) includes a main valve that opens and closes according to the pressure in the back pressure chamber, and a pilot valve provided in a pilot passage that adjusts the pressure in the back pressure chamber. This type of solenoid valve is characterized in that the bypass (81) is provided so as to bypass the pilot valve. According to this invention, generation | occurrence | production of the pressure difference which prevents opening and closing of a pilot valve can be suppressed. In addition, a minute flow rate by bypass can be realized by utilizing the flow path resistance of the pilot passage.

The invention according to claim 5 is characterized in that the bypass (291) is provided in the one-way valve (290) and bypasses the one-way valve (290). According to this invention, a bypass can be easily provided using a one-way valve.

The invention according to claim 6 is characterized in that the shape of the bypass (81, 291) corresponds to a round hole having a diameter of 0.06 mm or less. According to this invention, the density | concentration in the room | chamber interior of the refrigerant | coolant which leaked from the indoor heat exchanger can be restrained in a desirable range.

In the invention according to claim 7 , the shape of the bypass (81, 291) follows the change in the environmental temperature of the first part and the change in the environmental temperature of the second part, and the pressure of the first part and the second part. It is characterized in that it has a shape that allows a flow rate that substantially balances the pressure of the pressure, and a flow rate that allows a smaller flow rate than the pressure reducer bypass (33) provided in the pressure reducer (30). According to the present invention, even if a temperature difference occurs between the first part and the second part of the refrigeration cycle apparatus, a minute flow rate that allows the pressure of the first part and the pressure of the second part to be substantially balanced is allowed. As a result, even if there is a change in the environmental temperature at which the first part is placed, for example, a change in the indoor temperature, or an environmental temperature in which the second part is placed, for example, a change in the outdoor temperature, the pressure difference before and after the shut-off device is reduced. Can be suppressed. Moreover, the flow rate is made smaller than the flow rate of the decompressor bypass. As a result, it is possible to further suppress the leakage flow rate of the refrigerant from the first part as compared to the decompressor bypass alone.

The invention according to claim 8 is characterized in that the refrigerant of the refrigeration cycle apparatus is carbon dioxide. According to the present invention, it is possible to use carbon dioxide whose pressure tends to increase.

(First embodiment)
Hereinafter, a first embodiment in which the present invention is applied to a refrigeration cycle apparatus 1 for a vehicle air conditioner will be described. FIG. 1 is a block diagram showing the configuration of the refrigeration cycle apparatus 1. In FIG. 1, the refrigeration cycle apparatus 1 includes a compressor 10, a radiator 20, a decompressor 30, and an evaporator 40. These parts are sequentially connected by a plurality of pipes to form a closed circuit. Further, the refrigeration cycle apparatus 1 includes an internal heat exchanger 50, an accumulator 60, and a leakage suppression device 70. The refrigerant is carbon dioxide (CO ₂ ). This refrigeration cycle apparatus 1 constitutes a supercritical refrigeration cycle.

  The compressor 10 compresses the refrigerant to a high temperature and a high pressure. The compressor 10 is driven by an internal combustion engine. The compressor 10 may be driven by an electric motor instead of the internal combustion engine. The compressor 10 is a variable capacity type. The compressor 10 may be a fixed capacity type instead of the variable capacity type. The radiator 20 is an outdoor heat exchanger. The radiator 20 is connected to the discharge side of the compressor 10 and cools the refrigerant by heat exchange with outside air. The radiator 20 can also be called a condenser.

  The decompressor 30 decompresses the refrigerant flowing out of the radiator 20 in an enthalpy manner and expands it. The decompressor 30 is a pressure control valve. The decompressor 30 adjusts the opening of the valve so as to adjust the high-pressure side refrigerant pressure of the refrigeration cycle apparatus 1 to a predetermined value. The decompressor 30 is a temperature-sensitive pressure control valve that senses the high-pressure side refrigerant pressure as a temperature. The decompressor 30 includes a valve portion 31 that adjusts a passage area between the internal heat exchanger 50 and the evaporator 40. The decompressor 30 includes a power element 32 that adjusts the opening degree of the valve portion 31. The power element 32 detects the refrigerant temperature between the radiator 20 and the internal heat exchanger 50. The power element 32 increases the opening degree of the valve part 31 when the detected temperature is high because the refrigerant pressure is high, and decreases the opening degree of the valve part 31 when the detected temperature is low because the refrigerant pressure is low. The decompressor 30 is also called an expansion valve.

  The decompressor 30 has a bypass 33. The bypass 33 is also called a decompressor bypass. The bypass 33 is a passage that bypasses the valve portion 31. The bypass 33 is provided by a throttle passage that allows a small flow rate even when the valve portion 31 is in a fully closed state. The bypass 33 can be provided in a member constituting the valve portion 31. For example, it can be provided by a bleed hole or a bleed groove formed in the valve seat member or the movable valve member. The bypass 33 allows an initial flow rate for starting the refrigeration cycle apparatus 1. The initial flow rate causes the refrigerant radiated by the radiator 20 to reach the power element 32 after the compressor 10 starts rotating. The bypass 33 is also a pressure equalizing passage. The bypass 33 makes the pressures before and after the decompressor 30 equal by connecting the front and rear of the decompressor 30 when the refrigeration cycle apparatus 1 is stopped. The bypass 33 can also serve as a relief passage that avoids an excessive increase in the high-pressure side pressure of the refrigeration cycle apparatus 1.

  The evaporator 40 is an indoor heat exchanger and is also called a cooler or a heat absorber. The evaporator 40 cools the air to be cooled as the refrigerant evaporates inside. The internal heat exchanger 50 is provided between the high pressure passage and the low pressure passage. The internal heat exchanger 50 exchanges heat between the high-pressure refrigerant between the radiator 20 and the decompressor 30 and the low-pressure refrigerant between the evaporator 40 and the compressor 10. The accumulator 60 is provided between the evaporator 40 and the compressor 10. The accumulator 60 is positioned between the evaporator 40 and the internal heat exchanger 50.

  The leakage suppression device 70 is provided at a boundary portion between the engine room 2 and the vehicle compartment 3 of the vehicle. The leak suppression device 70 can be placed in the engine room 2. The leakage suppression device 70 includes a shut-off device. The shut-off device includes two shut-off valves located before and after the evaporator 40. Two shutoff valves are provided by a solenoid valve 80 and a one-way valve 90. The electromagnetic valve 80 is provided between the decompressor 30 and the evaporator 40. The one-way valve 90 is provided between the evaporator 40 and the accumulator 60.

  The refrigeration cycle apparatus 1 includes a bypass 81. The bypass 81 can also be called a shut-off valve bypass. The bypass 81 is provided in parallel with the electromagnetic valve 80 of the leakage suppression device 70. The bypass 81 is provided by a throttle passage that allows a minute flow rate even when the electromagnetic valve 80 is fully closed. The bypass 81 is provided integrally with the electromagnetic valve 80.

  FIG. 2 is a partial cross-sectional view of the electromagnetic valve 80. The electromagnetic valve 80 is a pilot type electromagnetic valve. A main passage that reaches the refrigerant outlet 80c from the refrigerant inlet 80b is formed in the body 80a. A main valve 80d is provided in the main passage. The main valve 80d has a fixed valve seat 80e and a movable valve body 80f. The valve body 80f is located upstream from the valve seat 80e. For this reason, the pressure of the refrigerant during operation acts in the direction in which the valve body 80f is seated on the valve seat 80e. The valve body 80f is a pressure responsive valve that moves according to the pressure difference. The back pressure chamber 80g formed behind the valve body 80f communicates with the main passage on the downstream side of the main valve 80d through the pilot passage. The pilot passage includes a gap between the outer periphery of the valve body 80f and the body 80a. A pilot valve 80h is provided in the pilot passage. The pilot valve 80h has a fixed valve seat 80i and a movable valve body 80j. The valve body 80j is driven by an electromagnetic solenoid 80k. When the electromagnetic solenoid 80k is energized, the pilot valve 80h is opened. When the pilot valve 80h is opened, a low pressure is introduced into the back pressure chamber 80g. As a result, the valve body 80f is pulled up and the main valve 80d is opened.

  A bleed hole 81a is provided so as to bypass the pilot valve 80h. The bleed hole 81a passes through the valve seat 80i. The bleed hole 81a forms a bypass 81 together with the pilot passage. That is, a passage that bypasses the main valve 80d is provided by the bleed hole 81a and the pilot passage. This configuration has an advantage that the bleed hole 81a can be formed relatively easily with a relatively large size.

  The first condition that the shape of the bypass 81 should satisfy is that an excessive pressure increase can be suppressed while the operation of the refrigeration cycle apparatus is stopped. The shape of the bypass 81 follows the change in the temperature in the engine room 2 and the change in the temperature in the passenger compartment 3 when the refrigeration cycle apparatus 1 is stopped. Allow a flow rate that nearly balances the pressure. This flow rate eliminates the pressure difference before and after the bypass 81 before the pressure in the outdoor portion rises excessively. Changes in the installation environment of the refrigeration cycle apparatus 1 such as changes in the outside air temperature or the room temperature occur relatively slowly. This change in the installation environment includes a change in atmospheric temperature, a temperature change in the passenger compartment 3 due to solar radiation, and a temperature change in the engine room 2 due to engine heat. The bypass 81 is required to allow such a flow rate as to balance the pressure in the refrigeration cycle apparatus 1 following such a slow temperature change.

  The second condition that the shape of the bypass 81 should satisfy is that the leakage flow rate can be suppressed to a predetermined amount or less. The flow path resistance provided by the shape of the bypass 81 suppresses the leakage flow rate even if the refrigerant leaks from the evaporator 40. The smaller the leakage flow rate, the better.

  In order to satisfy the first condition, the shape of the bypass 81 is desirably a shape corresponding to a small flow path resistance, that is, a large cross-sectional area. However, in order to satisfy the second condition, it is desirable that the shape of the bypass 81 is a shape corresponding to a large flow path resistance, that is, a small cross-sectional area. Therefore, the shape, particularly the size of the bypass 81 is determined so as to achieve both balancing of the pressure in the refrigeration cycle apparatus 1 and minimizing the leakage flow rate even when the environmental temperature changes. . In addition, it is desirable that the bleed hole 81a is large from the viewpoint of ease of machining and processing accuracy.

  The bleed flow rate allowed by the bypass 81 is smaller than the minimum refrigerant flow rate necessary for the refrigeration cycle apparatus 1 to operate. The bleed flow rate is smaller than the initial flow rate when the refrigeration cycle apparatus 1 is started. The initial flow rate is a flow rate provided by the decompressor bypass 33. The bleed flow rate is a flow rate at which the refrigerant concentration in the passenger compartment 3 can be maintained below the target concentration even if the refrigerant leaks into the passenger compartment 3 from the evaporator 40 or the pipes around it. The target concentration is determined according to the type of refrigerant. The target concentration can be set to achieve a value recommended by public institutions or industry associations.

  In the case of carbon dioxide, the concentration in the passenger compartment 3 fluctuates only by the breath of the passenger. Therefore, the target concentration is determined based on the maximum value of the carbon dioxide concentration in the passenger compartment 3 that can be reached only by the breath of the occupant. The target density can be not less than the maximum value and not more than three times the maximum value.

  FIG. 3 is a graph showing changes in the refrigerant concentration in the passenger compartment 3. The shape of the bypass 81 is indicated by the diameter of the round hole indicating the flow path resistance corresponding to the bypass 81. The refrigerant concentration increases with the start of leakage. The refrigerant concentration gradually decreases after reaching the peak due to the inside of the passenger compartment 3 being ventilated and the leakage amount gradually decreasing. The larger the bypass 81, the greater the gradient of the refrigerant concentration rise. The larger the bypass 81, the earlier the refrigerant concentration reaches its peak. The larger the bypass 81, the higher the refrigerant concentration peak value. The larger the bypass 81, the greater the slope of the decrease in refrigerant concentration. Based on the behavior of the refrigerant concentration, the shape of the bypass 81 is set so that the refrigerant concentration does not continuously exceed the target concentration over a predetermined time.

  The shape of the bypass 81 can be selected by measuring or predicting the moving average value of the refrigerant concentration over several minutes. For example, the shape of the bypass 81 is selected so that the average value of the refrigerant concentration over 15 minutes is 30000 ppm, that is, 3% or less. According to FIG. 3, when the shape of the bypass 81 is a shape corresponding to a round hole having a diameter of more than 0.06 mm, the average value of the refrigerant concentration in 15 minutes is likely to exceed 30000 ppm. Therefore, the shape of the bypass 81 is set to a shape corresponding to a round hole having a diameter of 0.05 mm.

  The leakage suppression device 70 described above is provided at a position that divides the inside of the refrigeration cycle device 1 into a first portion including the indoor heat exchanger 40 and another second portion. The leakage suppression device 70 can switch the communication state between the first part and the second part between a first state in which the refrigeration cycle apparatus 1 can be operated and a second state in which only a minute flow rate smaller than the first state is allowed. is there. This switching is performed by the electromagnetic valve 80. In the first state, the solenoid valve 80 and the one-way valve 90 can be fully opened, and the maximum passage cross-sectional area is given. In the second state, communication is possible only through the bypass 81 and a limited passage cross-sectional area is provided.

  In FIG. 1, the refrigeration cycle apparatus 1 includes a control device 100. The control device 100 controls the compressor 10 and the leakage suppression device 70. The control device 100 adjusts the discharge capacity in addition to switching between operation and stop of the compressor 10. The control device 100 controls the compressor 10 and the electromagnetic valve 80 according to the air conditioning request of the vehicle air conditioner. The control device 100 provides a control unit that drives the leakage suppression device 70 to a shut-off state when the refrigeration cycle apparatus 1 is stopped. Furthermore, the control device 100 can include means for detecting that an abnormality has occurred in the refrigeration cycle apparatus 1. When an abnormality occurs in the refrigeration cycle apparatus 1, the control apparatus 100 stops the refrigeration cycle apparatus 1 and drives the leakage suppression apparatus 70 to a cutoff state.

  The refrigeration cycle apparatus 1 has an indoor part as a first part and an outdoor part as a second part. The indoor portion is placed in the passenger compartment 3 or in an air conditioning unit communicating with the passenger compartment 3. The indoor parts include at least the evaporator 40 and its piping. The outdoor part is placed in the engine room 2 of the vehicle. The outdoor portion includes a compressor 10, a radiator 20, a decompressor 30, an internal heat exchanger 50, an accumulator 60, a leakage suppression device 70, and piping connecting them.

  FIG. 4 is a time chart showing the operation of the refrigeration cycle apparatus 1. FIG. 4A shows an air conditioning request. FIG. 4B shows the state of the electromagnetic valve 80. FIG. 4C shows the state of the compressor 10. When there is a request for air conditioning of the vehicle air conditioner and the signal A / C is in the ON state, the control device 100 opens the electromagnetic valve 80 in the ON state and operates the compressor 10 in the ON state. As a result, the refrigerant decompressed by the decompressor 30 passes through the electromagnetic valve 80 and evaporates in the evaporator 40. The evaporator 40 cools the conditioned air supplied into the passenger compartment 3. The refrigerant exiting the evaporator 40 flows by pushing the one-way valve 90 in the forward direction.

  When there is no air conditioning request and the signal A / C is turned off, the control device 100 first stops the compressor 10 by turning it off. After the delay time TD1, the control device 100 closes the electromagnetic valve 80 with the OFF state. On the other hand, when the compressor 10 stops, the differential pressure across the one-way valve 90 decreases, and the one-way valve 90 closes. In particular, the one-way valve 90 prevents back flow from the accumulator 60 to the evaporator 40. As a result, the refrigerant flow to the evaporator 40 is substantially blocked.

  While the signal A / C is in the OFF state, the solenoid valve 80 is closed and the one-way valve 90 is also closed. Even when the leakage suppression device 70 is in the shut-off state, the bypass 81 allows a minute refrigerant flow. When the outdoor part becomes high temperature and the refrigerant in the outdoor part becomes high pressure, the refrigerant in the outdoor part flows into the indoor part through the bypass 81. While the refrigeration cycle apparatus 1 is stopped, the inside of the refrigeration cycle apparatus 1 is communicated through the bypass 81 even if there is a change in environmental temperature that gives a temperature difference between the outdoor part and the indoor part. Maintained at pressure. The refrigerant spreads evenly throughout the refrigeration cycle apparatus 1. As a result, it is avoided that the refrigerant is biased to an undesirable state, and the differential pressure acting before and after the leakage suppression device 70 is suppressed.

  When the air conditioning request A / C is turned on, the control device first opens the electromagnetic valve 80 in the on state. The solenoid valve 80 is in a state where the main valve 80d can be opened by opening the pilot valve 80h. After delay time TD2, control device 100 operates with compressor 10 turned on. As a result, the one-way valve 90 is opened and the main valve 80d is opened. By the bypass 81, there is almost no differential pressure before and after the pilot valve 80h. For this reason, the pilot valve 80h can be opened reliably and quickly, and the refrigeration cycle apparatus 1 can be started up smoothly.

  When the evaporator 40 or the pipes before and after the evaporator 40 is damaged, the refrigerant leaked from the damaged portion leaks into the vehicle compartment 3. According to this embodiment, when the refrigeration cycle apparatus 1 stops operation, the leakage suppression apparatus 70 enters a shut-off state. As a result, the flow rate of the refrigerant flowing into the evaporator 40 is limited to the flow rate through the bypass 81. As a result, even when the evaporator 40 and the pipes before and after the evaporator 40 are damaged, a large amount of refrigerant is prevented from being suddenly released into the passenger compartment 3.

  When the refrigeration cycle apparatus 1 is not in operation, the indoor portion and the outdoor portion are partitioned by the leakage suppression device 70. At this time, the one-way valve 90 allows the refrigerant to move from the indoor portion to the outdoor portion. Furthermore, the bypass 81 provides a restricted communication state even when the leakage suppression device 70 is in the shut-off state. For this reason, the bypass 81 also allows the refrigerant to move from the indoor portion to the outdoor portion. When a temperature difference occurs between the indoor portion and the outdoor portion, the refrigerant moves to the low temperature side through the one-way valve 90 and the bypass 81. Thereafter, when the temperature of this outdoor part rises in a state where a large amount of refrigerant is stored in the low temperature side part, for example, the outdoor part, the bypass 81 allows a limited minute flow rate. Equilibrate pressure. For this reason, an excessive pressure difference is avoided.

  Therefore, it is possible to avoid the occurrence of a large pressure difference in the refrigeration cycle apparatus 1 due to the refrigerant stored unevenly. As a result, the valve can be opened and closed reliably, and the refrigeration cycle apparatus can be reliably started. Further, noise generated when the valve is opened can be suppressed. In particular, noise caused by a water hammer phenomenon can be suppressed. Furthermore, it is not necessary to set the pressure resistance performance of a part of the refrigeration cycle apparatus 1 higher than necessary. For example, although belonging to the outdoor portion, it is not necessary to set the pressure resistance of the accumulator, which is a low-pressure component, in consideration of the state in which the refrigerant is unevenly distributed.

  When the bypass 81 of this embodiment is not provided, the following problems are assumed to occur. For example, when the solar radiation is strong, the interior of the passenger compartment 3 is hot and the interior of the engine compartment 2 is relatively cold. In this case, the refrigerant in the evaporator 40 flows out to the accumulator 60 and the like through the one-way valve 90. As a result, the amount of refrigerant in the indoor portion decreases and the amount of refrigerant in the outdoor portion increases. At this time, the amount of refrigerant stored in the outdoor portion exceeds the amount corresponding to the ratio between the volume of the outdoor portion and the volume of the indoor portion. Next, when the temperature in the engine room 2 rises without starting the refrigeration cycle apparatus 1, the refrigerant pressure for the outdoor portion may reach an excessive pressure because the refrigerant amount is large. For example, when the vehicle is stopped after traveling uphill, the temperature in the engine room 2 rises to about 80 ° C. In such a case, if an excessive amount of refrigerant is stored in the outdoor portion, the refrigerant pressure for the outdoor portion may reach an excessive pressure. Such an excessive pressure may cause an excessive pressure difference to act before and after the shut-off device, making it difficult to open the shut-off device. From another viewpoint, in order to withstand an excessive pressure, it is necessary to set the volume of the accumulator 60 included in the outdoor portion sufficiently large. However, the large accumulator 60 is difficult to mount. In still another aspect, there is a risk that low-pressure components such as the accumulator 60 included in the outdoor portion are exposed to excessive pressure that exceeds the normal pressure during normal operation of the refrigeration cycle apparatus 1. Therefore, it is necessary for the low-pressure system parts belonging to the outdoor portion to have pressure resistance that can withstand high pressures exceeding normal operation. However, in order to provide high pressure resistance, it is difficult to avoid an increase in weight, an increase in size, and an increase in cost.

In contrast, according to this embodiment with the bypass 81, the bypass 81 balances the pressure. For this reason, the malfunction of the apparatus resulting from an excessive pressure difference does not arise. Further, a small accumulator 60 can be used. Furthermore, it is not necessary to particularly strengthen the pressure resistance of low-pressure components such as the accumulator 60.
(Second Embodiment)
A second embodiment in which the present invention is applied to a refrigeration cycle apparatus 201 of a vehicle air conditioner will be described. FIG. 5 is a block diagram showing a configuration of the refrigeration cycle apparatus 201. Differences from the first embodiment will be described. The leak suppression device 270 includes an electromagnetic valve 280 that does not have the bypass 81 and a one-way valve 290 that includes the bypass 291. The bypass 291 is provided in parallel with the one-way valve 290. The bypass 291 is provided by a throttle passage that allows a minute flow rate even when the one-way valve 290 is fully closed. The bypass 291 is provided integrally with the one-way valve 290.

  FIG. 6 is a cross-sectional view of the one-way valve 290. The one-way valve 290 is also called a check valve. The body 290a is formed with a passage that reaches the refrigerant outlet 290c from the refrigerant inlet 290b. A valve 290d is provided in the passage. The valve 290d has a fixed valve seat 290e and a movable valve body 290f. The valve body 290f is located downstream of the valve seat 290e. For this reason, the pressure of the refrigerant during operation acts in a direction in which the valve body 290f is separated from the valve seat 290e. A passage extending in the axial direction is formed on the outer peripheral surface of the valve body 290f.

  A bleed groove 291a is provided in the valve seat 290e so as to bypass the valve 290d. The bleed groove 291a opens to the upstream side and the downstream side of the seat surface of the valve seat 290e. The bleed groove 291a alone constitutes a bypass 291. The shape of the bleed groove 291a is a shape corresponding to a round hole having a diameter of 0.05 mm.

  According to this embodiment, similarly to the first embodiment, when the indoor portion is damaged or failed, the release of the refrigerant from the indoor portion can be suppressed, and when the indoor portion is normal, the blocking device of the leakage suppression device 270 Can be suppressed.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be modified or expanded as follows.

  According to FIG. 3, when the shape of the bypasses 81 and 291 is a shape corresponding to a round hole having a diameter of more than 0.06 mm, the average value of the refrigerant concentration for 15 minutes may exceed 30000 ppm. Therefore, it is desirable that the bypasses 81 and 291 have a shape corresponding to a round hole having a diameter of 0.06 mm or less. In consideration of the difficulty of processing the bleed hole 81a or the bleed groove 291a constituting the bypass 81, 291, the shape of the bypass 81, 291 is preferably a shape corresponding to a round hole having a diameter of 0.04 mm or more. From these viewpoints, the shape of the bypasses 81 and 291 can be a shape corresponding to a round hole having a diameter in the range of 0.04 mm to 0.06 mm.

  The bypass 81 may be provided in the valve seat 80e or the valve body 80f so as to bypass the main valve 80d. The bypasses 81 and 291 can be realized by a mode such as a hole, a groove, a pipe, or a gap between the valve body and the valve seat, respectively. The bypasses 81 and 291 can be provided by piping connecting the outdoor portion and the indoor portion without being integrated with the shutoff valve. The electromagnetic valve 80 may be an electromagnetic valve that directly drives the main valve with an electromagnetic solenoid instead of the pilot type. In this case, the bypass 81 is provided so as to bypass the main valve.

  Each of the two shut-off valves constituting the leakage suppression device 70 may be constituted by an electromagnetic valve. Moreover, the two shut-off valves constituting the leakage suppression device 70 may be configured by pressure responsive valves that open in response to the refrigerant pressure indicating the operating state of the refrigeration cycle apparatus. Furthermore, each of the two shut-off valves constituting the leakage suppression device 70 may include a bypass. In this case, the sum of the diameter of the round hole corresponding to the shape of one bypass and the diameter of the round hole corresponding to the shape of the other bypass is in the range of 0.04 mm to 0.06 mm.

  The pressure reducer bypass 33 may include a pressure responsive valve that opens the passage in response to excessive high pressure or excessive high temperature. The indoor heat exchanger may be a radiator. This configuration makes it possible to apply the present invention to a heat pump device. The control device 100 may control the compressor 10 and the electromagnetic valve 80 without giving the delay time TD1 or TD2. Furthermore, the refrigeration cycle apparatus can include an ejector.

1 is a block diagram showing a first embodiment of a refrigeration cycle apparatus to which the present invention is applied. It is a fragmentary sectional view which shows the structure of the solenoid valve in 1st Embodiment. It is a graph which shows the change of the refrigerant | coolant density | concentration in 1st Embodiment. It is a time chart which shows the action | operation of the refrigerating-cycle apparatus in 1st Embodiment, Comprising: (A) shows an air-conditioning request | requirement, (B) shows the state of the solenoid valve 80, (C) shows the state of the compressor 10. FIG. . It is a block diagram which shows 2nd Embodiment of the refrigerating-cycle apparatus to which this invention is applied. It is sectional drawing which shows the structure of the one way valve in 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Refrigeration cycle apparatus, 10 Compressor, 20 Radiator, 30 Pressure reducer, 33 Bypass, 40 Evaporator, 50 Internal heat exchanger, 60 Accumulator, 70 Leakage suppression device, 80 Solenoid valve, 81 Bypass, 90 One-way valve, DESCRIPTION OF SYMBOLS 100 Control apparatus, 201 Refrigeration cycle apparatus, 270 Leakage suppression apparatus, 280 Solenoid valve, 290 One-way valve, 291 Bypass

Claims (8)

In the refrigeration cycle apparatus (1, 201) including the compressor (10), the outdoor heat exchanger (20), the decompressor (30), and the indoor heat exchanger (40),
The refrigeration cycle apparatus is provided at a position that divides the interior of the refrigeration cycle apparatus into a first part including the indoor heat exchanger (40) and another second part, and a communication state between the first part and the second part Including a leakage suppression device (70, 270) capable of switching between a first state in which the refrigeration cycle device can be operated and a second state in which only a minute flow rate smaller than the first state is allowed ,
The leakage suppression device (70, 270)
A blocking device (80, 90, 280, 290) for blocking between the first part and the second part;
The blocking device is provided to bypass the refrigeration cycle apparatus according to claim Rukoto a bypass (81,291) to allow the micro-flow. The blocking devices (80, 90, 280, 290)
A solenoid valve (80, 280) provided upstream of the evaporator (40);
A one-way valve (90, 290) provided on the downstream side of the evaporator,
The refrigeration cycle apparatus according to claim 1 , wherein the bypass (81, 291) is provided in at least one of the electromagnetic valve and the one-way valve. The refrigeration cycle apparatus according to claim 2 , wherein the bypass (81) is provided in the electromagnetic valve (80) and bypasses the electromagnetic valve (80). The solenoid valve (80)
A main valve that opens and closes according to the pressure in the back pressure chamber;
A pilot type solenoid valve comprising a pilot valve provided in a pilot passage for adjusting the pressure of the back pressure chamber;
The bypass (81)
The refrigeration cycle apparatus according to claim 3 , wherein the refrigeration cycle apparatus is provided to bypass the pilot valve. The refrigeration cycle apparatus according to claim 2 , wherein the bypass (291) is provided in the one-way valve (290) and bypasses the one-way valve (290). The refrigeration cycle apparatus according to any one of claims 1 to 5 , wherein the bypass (81, 291) has a shape corresponding to a round hole having a diameter of 0.06 mm or less. The shape of the bypass (81, 291) is
Following the change in the environmental temperature of the first part and the change in the environmental temperature of the second part, the shape allows a flow rate that substantially balances the pressure of the first part and the pressure of the second part. ,
The refrigeration cycle apparatus according to any one of claims 1 to 6 , wherein the refrigeration cycle apparatus has a shape that allows a smaller flow rate than a decompressor bypass (33) provided in the decompressor (30). The refrigeration cycle apparatus according to any one of claims 1 to 7 , wherein the refrigerant of the refrigeration cycle apparatus is carbon dioxide.

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