JP2009036503A - Refrigerating cycle device and air conditioner having this refrigerating cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of requiring much time for defrosting the whole evaporator, due to reduction in refrigerant energy for melting frost of an evaporator tail end part, since heat is exchanged with surrounding air in a part of completing defrosting such as the vicinity of an evaporator inlet in defrosting. <P>SOLUTION: This refrigerating cycle device is constituted so that a delivery refrigerant of a compressor 1 is bypassed in the middle of a refrigerant flow passage of an evaporator 4 in the defrosting, and has a plurality of delivery gas refrigerants flowed in the evaporator 4 like a second delivery gas bypass 32 and an evaporator gas bypass 34, and thus, since not only that the heat is exchanged with the surrounding air in a defrosting finished part of the evaporator 4 by partially defrosting the evaporator 4 only in the vicinity of an inlet 4a can be restrained but also that a temperature rise in the evaporator 4 by reduction in flow passage resistance in the evaporator can be expected, the air conditioner for restraining reduction in amenity by a room temperature drop in heating operation by shortening a defrosting time, can be provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus including a bypass circuit for melting frost attached to an evaporator using a discharge gas refrigerant of a compressor.

  Conventionally, in this type of refrigeration cycle apparatus, high-temperature and high-pressure discharge gas refrigerant compressed by a compressor flows into a condenser via a four-way valve, and the refrigerant is condensed by heat exchange. The condensed refrigerant is depressurized by the expansion device, becomes a gas-liquid two-phase state, flows into the evaporator, evaporates by performing heat exchange, and is sucked into the compressor again through the four-way valve. Here, when the ambient temperature of the evaporator is low, frost gradually adheres to the evaporator, and the capacity decreases as the amount of frost attached increases.

  Therefore, it is necessary to melt the frost adhering to the evaporator. Generally, there is a method of melting the frost by switching the four-way valve and performing reverse cycle operation to reverse the function of each heat exchanger. . However, in this method, the original heating operation is stopped, the temperature on the condenser side is lowered, and unpleasant feeling due to a sudden room temperature drop is caused.

  Also, as a method not to perform such reverse cycle operation, by providing a branch pipe in the discharge pipe through which the refrigerant discharged from the compressor flows, a part of the refrigerant flows to one condenser of the branch pipe and the rest is the other There is a defrosting method in which the frost adhering to the evaporator is dissolved while continuing the heating operation, although the heating capacity is reduced by flowing into the evaporator via a refrigerant control device such as an electromagnetic valve (for example, Patent Documents) 1).

FIG. 3 shows a refrigeration cycle apparatus of a conventional air conditioner described in Patent Document 1. In FIG. 3, the outdoor unit B includes a compressor 1, a four-way valve 11, a throttle device 3, and an evaporator 4, and the indoor unit A includes a condenser 2 to constitute a refrigeration cycle during heating operation. A discharge refrigerant bypass 30 from the discharge pipe 1 a to the pipe line between the expansion device 3 and the evaporator 4 is configured via the branch pipe 5 and the electromagnetic valve 6. In this configuration, frost adheres to the evaporator 4 when the heating operation is continued. Therefore, as the defrosting operation, when the operation of the heat exchangers of the condenser 2 and the evaporator 4 remains in the heating operation state and the electromagnetic valve 6 of the discharge refrigerant bypass 30 is opened, the discharge gas refrigerant is transferred to the evaporator 4. The defrosting is performed by directly flowing in, and the evaporator 4 can be defrosted while continuing the heating operation.
Japanese Utility Model Publication No. 60-10178

  However, in the above-described conventional configuration, the refrigerant that has become hot due to the bypass refrigerant discharged from the compressor flows in from the inlet of the evaporator, and advances the refrigerant in the evaporator sequentially while supplying refrigerant energy to the evaporator. The frost in the vicinity of the inlet immediately after the refrigerant flows into the evaporator is defrosted in a relatively short time, but it takes longer to defrost toward the outlet side. In such a state, the portion where the defrosting near the evaporator inlet is completed quickly is subject to heat exchange with the surrounding air, and the temperature decreases regardless of the defrosting. The refrigerant energy that dissolves the nearby frost is reduced, and it takes more time to defrost the entire evaporator. If it becomes so, since the heating operation in which the capability fell will continue, it had the subject that room temperature would fall gradually and comfort would fall.

The present invention solves the above-described conventional problems, and provides an air conditioner that shortens the defrosting time and includes the refrigeration cycle device to suppress a decrease in comfort due to a decrease in room temperature during heating operation. With the goal.

  In order to solve the above-described conventional problems, the refrigeration cycle apparatus of the present invention is configured such that the refrigerant discharged from the compressor is bypassed in the refrigerant flow path of the evaporator during defrosting. As a result, the amount of refrigerant discharged at the time of defrosting is reduced in the amount of heat exchanged with the surrounding air at the defrosting completion part, and defrosting progresses from a place near the outlet in the middle of the refrigerant flow path of the evaporator. Heat can be effectively used for defrosting, the temperature of the evaporator can be increased, the degree of superheat of the compressor and the temperature of the discharged refrigerant can be increased, and the defrosting time can be suppressed while suppressing the decrease in the capacity of the condenser Can be shortened.

  Moreover, by setting it as the air conditioner provided with such a refrigerating-cycle apparatus, it becomes possible to reduce the defrost time and to suppress the fall of the comfort by the room temperature fall at the time of heating operation.

  The refrigeration cycle apparatus of the present invention can reduce the defrosting time because the amount of heat exchanged between the discharged refrigerant bypassed and the surrounding air can be reduced at the portion of the evaporator where the defrosting is completed at the time of defrosting. In a machine, the fall of comfort can be suppressed by suppressing the room temperature fall at the time of the defrost in heating operation.

  According to a first aspect of the present invention, a compressor, a four-way valve, a condenser, a throttling device, and an evaporator are connected in order by a pipe to constitute a refrigeration cycle, and the refrigerant is placed in the middle of the refrigerant flow path of the evaporator. A first discharge refrigerant bypass that bypasses the discharge refrigerant from the discharge pipe of the compressor, and a second discharge refrigerant that bypasses the discharge refrigerant from the discharge pipe of the compressor to an evaporator pipe connecting the expansion device and the evaporator A refrigeration cycle apparatus having a configuration in which a bypass is provided so that the discharged refrigerant flows through the two discharged refrigerant bypasses during defrosting in heating operation.

  With this configuration, the high-temperature refrigerant bypassed from the discharge pipe for performing defrosting is introduced into the evaporator through a plurality of inlets of the original inlet and the intermediate inlet in the refrigerant flow path of the evaporator to perform the defrosting. As a result, the defrosting of the evaporator is performed only from the original inlet at the time of defrosting, and the temperature of the evaporator is reduced by heat exchange between the bypassed discharged refrigerant and the surrounding air. In addition to suppressing the decrease, the defrosting can proceed from the vicinity of the outlet in the middle of the refrigerant flow path of the evaporator, and the heat of the refrigerant can be effectively used for the defrosting. Thus, the degree of superheat of the compressor and the temperature of the discharged refrigerant can be increased, and the defrosting time of the evaporator can be significantly shortened while suppressing a decrease in the capacity of the condenser.

  According to a second aspect of the present invention, a compressor, a four-way valve, a condenser, a throttling device, and an evaporator are connected in order by a pipe to constitute a refrigeration cycle, and the refrigerant is placed in the middle of the refrigerant flow path of the evaporator. A refrigeration cycle apparatus having a configuration in which a first discharge refrigerant bypass that bypasses a discharge refrigerant from a discharge pipe of a compressor is provided, and the discharge refrigerant flows through the first discharge refrigerant bypass during defrosting in heating operation is there.

With this configuration, normal refrigerant without bypass flows into the original inlet of the refrigerant flow path of the evaporator, and hot refrigerant bypassed from the discharge pipe flows into the middle inlet of the refrigerant flow path of the evaporator. The defrosting is performed by allowing the refrigerant for performing defrosting to flow into the evaporator from a plurality of inlets, so that the vicinity of the outlet having a large amount of frost can be sufficiently defrosted and evaporated during defrosting. In the part of the evaporator where the defrosting of the vessel is performed only from the original inlet and the frost has melted quickly, the bypassed refrigerant is prevented from exchanging heat with the surrounding air and decreasing in temperature. Therefore, the heat of the refrigerant can be effectively used for defrosting, and the defrosting time of the evaporator can be shortened while suppressing the decrease in the capacity of the condenser. In particular, it is possible with a simple system compared to the refrigeration cycle of the first invention.

  According to a third aspect of the invention, in particular, the refrigeration cycle apparatus according to the first or second aspect further includes a third discharge refrigerant bypass for bypassing the discharge refrigerant in the suction pipe of the compressor. This makes it possible to increase the degree of superheat of the compressor and the temperature of the discharged refrigerant and further increase the temperature of the evaporator, thereby further reducing the defrosting time of the evaporator while suppressing a decrease in the capacity of the condenser. It becomes possible.

  In the fourth aspect of the invention, in particular, the flow rate of the refrigerant discharged from the compressor of the refrigeration cycle apparatus of the first to third aspects of the bypass bypassing one or more discharge refrigerant bypasses is greater than the flow rate flowing to the four-way valve. It is the comprised refrigeration cycle apparatus. As a result, more refrigerant is discharged to the bypass side than the four-way valve side, so that the temperature of the evaporator can be increased and the defrosting time of the evaporator can be shortened.

  In the fifth aspect of the invention, in particular, the overall flow path resistance on the discharge refrigerant bypass side of the refrigeration cycle apparatus of the fourth invention is made smaller than the flow path resistance on the condenser side. It is possible to increase the flow rate that flows to the four-way valve on the condenser side.

  In the sixth aspect of the invention, in particular, the discharge refrigerant bypass of the refrigeration cycle apparatus of the first to fifth aspects of the invention is provided, and a branch pipe is provided in the discharge pipe. It is connected so that the dynamic pressure component acts greatly, and the dynamic pressure component of the discharged refrigerant is greatly applied to the bypass side, so that the refrigerant distribution ratio in the branch pipe becomes larger on the bypass side than on the four-way valve side, and the refrigerant on the bypass side The flow rate can be increased. Further, the circulation amount can be maintained even if there is a refrigerant control device installed in the discharge refrigerant bypass, that is, the influence of the flow path resistance of the refrigerant control device can be reduced, and after the refrigerant branching The selection range of the refrigerant control device connected to the bypass side can be improved.

  In the seventh aspect of the invention, in particular, the discharge refrigerant bypass of the refrigeration cycle apparatus of the fourth to sixth aspects of the invention is provided with a T-shaped branch pipe in the discharge pipe, and the discharge refrigerant of the compressor is linear in the direction of the discharge refrigerant bypass. The flow resistance in the direction of the four-way valve is bent so that the flow resistance in the discharge refrigerant bypass direction can be made smaller than the flow resistance in the condenser direction, and the discharge refrigerant of the compressor The dynamic pressure component can be applied to the direction more than the direction of the four-way valve.

  In the eighth aspect of the invention, in particular, the flow from the bypass is linearized by the T-shaped tube at the location where the outlet of at least one discharge refrigerant bypass of the first to seventh refrigeration cycle apparatuses joins the piping of the refrigeration cycle. Thus, the flow resistance of the discharge refrigerant bypass can be made smaller than the flow resistance on the condenser side, and the flow rate of the refrigerant on the bypass side can be increased.

  The ninth aspect of the invention is a discharge refrigerant bypass in which the pipe length of the longest discharge refrigerant bypass is made shorter than the pipe length on the condenser side among the one or more discharge refrigerant bypasses of the first to eighth refrigeration cycle apparatuses. Can be made smaller than the flow path resistance on the condenser side, and the flow rate of the refrigerant on the bypass side can be increased.

  In the tenth aspect of the invention, in particular, among the one or more discharge refrigerant bypasses of the first to ninth refrigeration cycle apparatuses, the pipe diameter of the thickest discharge refrigerant bypass is made equal to or larger than the pipe diameter on the condenser side. Thus, the flow resistance of the discharge refrigerant bypass can be made smaller than the flow resistance of the condenser side, and the flow rate of the refrigerant on the bypass side can be increased.

  In the eleventh aspect of the invention, in particular, 50% to 90% of the discharged refrigerant flows in the discharged refrigerant bypass of the first to tenth refrigeration cycle apparatuses, so that a larger amount of discharged refrigerant flows to the bypass side. In addition, it is possible to increase the temperature of the evaporator, the degree of superheat of the compressor and the temperature of the discharged refrigerant, and further increase the temperature of the evaporator. The frost time can be shortened.

  A twelfth aspect of the present invention is an air conditioner that includes an indoor unit and an outdoor unit each having a blower, and includes the refrigeration cycle apparatus according to any one of claims 1 to 11, and a defrosting time. With the refrigeration cycle apparatus that can shorten the temperature, a decrease in room temperature during defrosting in heating operation can be suppressed, and a decrease in comfort can be suppressed.

  In the thirteenth aspect of the invention, in particular, the indoor unit of the air conditioner of the twelfth aspect of the invention is provided with an auxiliary heating device to compensate for a decrease in heating capacity during defrosting in heating operation, thereby further suppressing a decrease in room temperature. Thus, it is possible to further suppress a decrease in comfort.

  Hereinafter, embodiments of the refrigeration cycle apparatus of the present invention will be described with reference to the drawings as examples mounted on an air conditioner. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a refrigerant system diagram of the refrigeration cycle apparatus according to Embodiment 1 of the present invention and shows a refrigerant flow as an air conditioner (in the direction of a solid arrow during heating operation). In FIG. 1, a compressor 1 that compresses refrigerant, a four-way valve 11 that changes the flow of refrigerant, a condenser 2 that condenses high-pressure and high-temperature refrigerant, a throttling device 3 that decompresses condensed refrigerant, and evaporates the decompressed refrigerant. The evaporator 4 is connected by piping in order, and the normal refrigeration cycle is comprised. Here, the condenser 2 is provided in the indoor unit A, and the others are provided in the outdoor unit B. The indoor unit A further includes an indoor fan 7 and an electric heater 9, and the outdoor unit B includes the outdoor fan 8. I have.

  In the first embodiment, the refrigeration cycle apparatus is provided with a plurality of discharge refrigerant bypasses that bypass the condenser 2 with the discharge gas refrigerant from the compressor 1. That is, a first discharge gas bypass 31 is provided which branches at the discharge pipe 1a in front of the four-way valve 11 to flow the entire flow rate of the discharge refrigerant bypass, and further branches from there, between the expansion device 3 and the evaporator 4. The second discharge gas bypass 32, which is the second discharge refrigerant bypass, bypassed to the evaporator pipe 10, and the first discharge refrigerant bypass, bypassed to the inlet 4c in the middle of the refrigerant flow path of the evaporator 4. An evaporator path bypass 34 and a third discharge gas bypass 33 that is a third discharge refrigerant bypass that bypasses the suction pipe 1 b of the compressor 1 are provided. That is, here, the discharge refrigerant bypass is composed of the first discharge gas bypass 31, the second discharge gas bypass 32, the third discharge gas bypass 33, and the evaporator path bypass 34 branched therefrom.

  A refrigerant control device 40 is provided in the middle of the first discharge gas bypass 31 to allow the discharge gas refrigerant to flow arbitrarily, and the entire refrigerant flow is controlled as necessary. Further, an evaporator bypass flow rate adjustment pipe 32a and a check valve 32b are provided in the middle of the second discharge gas bypass 32, and a suction bypass flow rate adjustment pipe 33a is provided in the middle of the third discharge gas bypass 33, and further, evaporation An evaporator path bypass flow rate adjustment pipe 34a and a check valve 34b are provided in the middle of the evaporator path bypass 34 to balance the flow rates of the second discharge gas bypass 32, the third discharge gas bypass 33, and the evaporator path bypass 34. It is adjusted.

Further, the branch of the first discharge gas bypass 31 in the discharge pipe 1 a is performed by including a substantially T-shaped branch pipe 51. In this branch pipe 51, the refrigerant discharged from the compressor 1 flows linearly in the direction of the first discharge gas bypass 31 (arrow D1), and bends substantially perpendicularly to the direction of the four-way valve 11 (arrow D2). It is configured.

  Further, T-shaped pipes 52 and 53 similar to the branch pipe 51 are also obtained in the merge to the evaporator pipe 10 at the outlet of the second discharge gas bypass 32 and the merge to the suction pipe 1b at the outlet of the third discharge gas bypass 33. It has. That is, in the merge of the T-shaped tube 52 on the heat exchanger pipe 10 side, the flow as the evaporator pipe 10 from the expansion device 3 is bent substantially at right angles (arrow D3), and the second discharge gas bypass 32 is configured. Is connected so as to flow linearly to the evaporator pipe 10 (arrow D4). Further, when the T-shaped pipe 53 on the suction pipe 1b side is merged, the original flow as the suction pipe 1b from the four-way valve 11 is bent substantially at a right angle (arrow D5), and from the third discharge gas bypass 33 Are connected to the suction pipe 1b so as to flow linearly (arrow D6).

  About the air conditioner provided with the refrigerating-cycle apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. First, at the time of heating operation, as indicated by a solid line arrow, the high-temperature and high-pressure discharge gas refrigerant compressed by the compressor 1 flows into the condenser 2 of the indoor unit A through the four-way valve 11 and performs heat exchange. Is condensed and the room is heated. The condensed refrigerant enters the outdoor unit B, is decompressed by the expansion device 3, enters a gas-liquid two-phase state, flows into the evaporator 4, evaporates by performing heat exchange, and absorbs outdoor heat. Then, it is sucked again into the compressor 1 through the four-way valve 11. During this normal heating operation, the refrigerant control device 40 is closed.

  Here, when the ambient temperature of the evaporator 4 is low, frost gradually adheres to the evaporator 4, and the heating capacity decreases as the amount of frost attached increases. Incidentally, with regard to the progress of frost formation, the closer to the outlet of the evaporator 4, the lower the pressure and the lower the temperature, so that frosting starts from the vicinity of the outlet 4 b and spreads toward the inlet 4 a side.

  Therefore, when the control device (not shown) detects the outlet temperature of the evaporator 4 and the like, the refrigerant control device 40 provided in the first discharge gas bypass 31 is opened when the amount of frost formation has increased to a predetermined amount. The evaporator 4 is defrosted by flowing the discharge gas refrigerant through the second discharge gas bypass 32, the third discharge gas bypass 33, and the evaporator path bypass 34. This promotes melting of frost by raising the temperature of the evaporator 4 in the second discharge gas bypass 32 and the evaporator path bypass 34.

  In particular, the high-temperature refrigerant for defrosting is supplied to the refrigerant flow path of the evaporator 4 by flowing through the evaporator path bypass 34 and joining the inlet 4c in the middle of the refrigerant flow path of the evaporator 4. The defrosting is also performed from the vicinity of the outlet 4b of the evaporator 4 by flowing into the evaporator 4 from the middle inlet 4c, so that the defrosting of the evaporator 4 is performed only from the original inlet 4a and the frost is quickly generated. Since it is possible to suppress the temperature from decreasing due to heat exchange with the surrounding air at the melted part, the amount of refrigerant discharged at the time of defrosting heat exchange with the surrounding air at the defrosting completed part is suppressed. The defrosting can proceed from the vicinity of the outlet in the middle of the refrigerant flow path of the evaporator, so that the heat of the refrigerant can be effectively used for the defrosting, the temperature rise of the evaporator, the degree of superheat of the compressor and the discharge The temperature of the refrigerant can be increased and the capacity of the condenser is low. It is possible to shorten the defrosting time while suppressing. Thereby, the frost adhering to the evaporator 4 can be melt | dissolved in a short time, indoor temperature change can be decreased more, and the fall of the comfort by room temperature fall can be suppressed.

  Further, in the third discharge gas bypass 33, the temperature of the compressor 1 and the discharge gas refrigerant is increased by increasing the dryness of the compressor 1, and thereby the temperature of the evaporator 4 is further increased. . When configured in this way, although the heating capacity is reduced by defrosting in the heating operation state without switching the four-way valve 11, the temperature of the room being heated as compared with the system that defrosts in the reverse cycle A change can be made smaller and the fall of the comfort by the room temperature fall can be suppressed.

  The first discharge gas bypass 31 does not necessarily have to be diverted to the third discharge gas bypass 33 and flow the discharge gas refrigerant, but only flows to the second discharge gas bypass 32 and the evaporator path bypass 34. However, it is possible to defrost in the heating operation state. That is, instead of the refrigerant control device 40 having the above-described configuration, a refrigerant control device may be provided in each of the second discharge gas bypass 32 and the third discharge gas bypass 33, and the control may be performed according to the operating condition or the like. .

  Next, in the first embodiment, the discharge gas refrigerant from the compressor 1 is caused to flow from the first discharge gas bypass 31 to the second discharge gas bypass 32, the third discharge gas bypass 33, and the evaporator path bypass 34. For circulation, a T-shaped branch pipe 51 is further provided at the branch of the first discharge gas bypass 31 in the discharge pipe 1 a of the compressor 1. In particular, the branch pipe 51 is configured such that the refrigerant discharged from the compressor 1 flows linearly in the direction of the first discharge gas bypass 31 and is bent at a right angle in the direction of the four-way valve 11. With this configuration, the discharge gas refrigerant has a larger dynamic pressure component in the direction of the first discharge gas bypass 31 than in the direction of the four-way valve 11. Then, due to the action of the dynamic pressure, the refrigerant distribution ratio in the branch pipe 51 becomes larger on the first discharge gas bypass 31 side, and the flow rate of the discharge gas refrigerant on the first discharge gas bypass 31 side can be increased.

  Thereby, the frost adhering to the evaporator 4 can be melt | dissolved in a shorter time, a room temperature change can be decreased more, and the fall of the comfort by a room temperature fall can be suppressed more. In particular, by setting the flow rate of the discharge gas refrigerant flowing to the first discharge gas bypass 31 to be larger than the flow rate of flowing to the four-way valve 11, even if the room temperature temporarily decreases due to a decrease in heating capacity, it is even shorter. By completing the defrosting, a great effect of suppressing a decrease in comfort can be obtained.

  Further, the T-shaped pipes 52 and 53 are also used on the merging side of the suction pipe 1b and the evaporator pipe 10, and the outlet of the second discharge gas bypass 32 and the outlet of the third discharge gas bypass 33 join the refrigeration cycle pipe. The flow rate from the discharge pipe 1a to the first discharge gas bypass 31 is set to be higher by connecting the pipes so that the flow at the pipes is linear and making the flow path resistance small so as not to disturb the flow as much as possible. Is possible. Note that the T-shaped branch pipe 51 and the T-shaped pipes 52 and 53 do not necessarily need to be completely T-shaped, and the discharge gas bypass side can be configured with less channel resistance than the condenser 2 side. good.

  As described above, by providing a plurality of discharge gas refrigerants that flow into the evaporator 4 such as the second discharge gas bypass 32 and the evaporator path bypass 34, the defrosting of the evaporator 4 is biased toward the single inlet 4a. Thus, the amount of heat exchange with the surrounding air at the portion where the defrosting of the evaporator 4 is completed can be reduced, and the temperature of the evaporator 4 can be increased by reducing the flow resistance in the evaporator 4. Since it can be expected, it is possible to provide an air conditioner that shortens the defrosting time and suppresses a decrease in comfort due to a decrease in room temperature.

  Further, the branch pipe is configured such that the dynamic pressure component of the discharge gas refrigerant acts on the first discharge gas bypass 31 side, or the flow resistance is reduced even in the merging so as to flow smoothly. In the design of the refrigerant control device 40, for example, the diversion ratio at 51 increases toward the first discharge gas bypass 31, and the influence of the flow path resistance of the refrigerant control device 40 installed in the first discharge gas bypass 31 decreases. The margin can be increased, thereby reducing the cost.

Of the refrigerant pipes in the path from the first discharge gas bypass 31 to the second discharge gas bypass, from the first discharge gas bypass to the second discharge gas bypass, or from the first discharge gas bypass to the evaporator path bypass The longest pipe length is shorter than the pipe length of the refrigerant pipe on the condenser 2 side, or the pipe diameter is also made equal to or larger than that, so that the flow resistance on the discharge gas bypass side is reduced to the flow on the condenser 2 side. It is possible to set a larger flow rate from the discharge pipe 1a to the first discharge gas bypass 31 by making it smaller than the path resistance.

  As described above, as shown in some embodiments, the overall flow resistance from the branch part of the discharge pipe 1a on the discharge gas bypass side to the suction of the compressor 1 excluding the condenser 2 side pipe is condensed. The flow rate from the discharge pipe 1a to the first discharge gas bypass 31 is reduced by reducing the flow resistance from the branch portion of the discharge pipe 1a on the container 2 side to the suction of the compressor 1 excluding the discharge gas bypass side pipe. It is possible to set more than the flow rate flowing to the four-way valve 11 on the condenser 2 side.

  In this way, by configuring the flow rate of the discharge gas refrigerant of the compressor 1 to flow through the first discharge gas bypass 31 at the time of defrosting to be greater than the flow rate of flowing to the four-way valve 11, the temperature rise of the evaporator 4 can be further increased. In addition, the temperature of the evaporator 4 can be further increased by the degree of superheat of the compressor 1 and the temperature of the discharge gas refrigerant, and the evaporator 4 can be removed while suppressing a decrease in the capacity of the condenser 2. It becomes possible to shorten frost time more. Further, since the degree of influence of the flow path resistance of the refrigerant control device 40 installed in the first discharge gas bypass 31 is reduced, the degree of freedom in design is improved and the cost can be reduced accordingly. Furthermore, by providing the refrigeration cycle apparatus configured as described above, it is possible to provide an air conditioner that suppresses a decrease in comfort due to a decrease in room temperature.

  The ratio of the diversion to the first discharge gas bypass 31 is usually less than 50%, and the defrosting time for melting the frost is also relatively long. In the first embodiment, the first discharge gas bypass is used. 31 is configured such that 50% to 90% of the discharged refrigerant flows, and the defrosting is completed in about 3 minutes to 7 minutes depending on the ambient temperature condition. Thereby, although the circulation amount of the refrigerant | coolant to the condenser 2 of the indoor unit A falls, the fall of heating capability is suppressed by enlarging the dryness of the compressor 1 and raising the temperature of discharge gas refrigerant | coolant etc. You can also. Furthermore, if the indoor unit A is provided with, for example, an electric heater 9 as an auxiliary heating device, it is possible to compensate for a decrease in heating capacity in the refrigeration cycle, and to further suppress a decrease in comfort due to a decrease in room temperature.

(Embodiment 2)
FIG. 2 is a refrigerant system diagram of the refrigeration cycle apparatus according to Embodiment 2 of the present invention and shows the flow of refrigerant as an air conditioner (in the direction of the solid arrow during heating operation). In FIG. 2, the normal refrigeration cycle is the same as in FIG. 1, except that there is no second discharge gas bypass 32 that bypasses the evaporator pipe 10 between the expansion device 3 and the evaporator 4.

  The heat transfer tube near the inlet 4a of the evaporator 4 during normal heating operation has a higher refrigerant temperature than the heat transfer tube near the outlet 4b due to the resistance in the tube of the evaporator 4, and as described in the first embodiment, Regarding the progress, the closer to the outlet of the evaporator 4, the lower the pressure and the lower the temperature, so that frosting starts from the vicinity of the outlet 4b and spreads toward the inlet 4a. From such a process, even when frost spreads over the entire evaporator 4, the area near the outlet 4 b has a larger frost thickness and a larger amount of frost formation, and the area near the inlet 4 a has a smaller frost formation and frost. Usually, there is little adhesion amount. Therefore, in the defrosting operation, the expansion device 3 is opened more than in the heating operation to raise the refrigerant temperature from the indoor unit, so that the frost can be generated only by the refrigerant flowing into the inlet 4a of the evaporator 4 in the normal refrigeration cycle. Dissolution is possible.

  That is, in the second embodiment, assuming that frost formation is in such a state, the second discharge gas bypass 32 is omitted, and the discharge gas refrigerant from the compressor 1 is used as the first discharge gas. Frost adhering to the evaporator 4 is dissolved in a short time by flowing through the third discharge gas bypass 33 and the evaporator path bypass 34 from the bypass 31 to the suction of the compressor 1.

  In particular, by flowing through the evaporator path bypass 34 and joining the inlet 4c in the middle of the refrigerant flow path of the evaporator 4, in addition to allowing normal refrigerant to flow into the original inlet 4a, defrosting is performed. A high-temperature refrigerant for carrying out the desorption is introduced into the inlet 4c in the middle of the refrigerant flow path of the evaporator 4 and defrosting is performed also from a position close to the outlet 4b of the evaporator 4, whereby the outlet 4b having a large amount of frost attached It can be sufficiently defrosted in the vicinity, and the defrosting of the evaporator 4 is performed only from the original inlet 4a, and the temperature is increased by heat exchange with the surrounding air at the part where the frost in the vicinity has melted quickly. Since it can also suppress that it falls, the frost adhering to the evaporator 4 can be melt | dissolved in a short time, indoor temperature change can be decreased more, and the fall of the comfort by room temperature fall is suppressed. Can do. In particular, a simple system is possible as compared with the refrigeration cycle of the first embodiment.

  Furthermore, even in the configuration where the refrigerant is merged with the inlet 4c in the middle of the refrigerant flow path of the evaporator 4, the flow path resistance is configured to be small so as to prevent the flow from the bypass as much as possible by linearly connecting with the T-shaped tube 54. It becomes possible to set a larger flow rate to the evaporator path bypass 34.

  In addition, about the position of the inlet 4c in the middle of the refrigerant | coolant flow path of the evaporator 4, in FIG.1 and FIG.2, it is set as before the refrigerant | coolant flow path of the evaporator 4 branches to a some path | pass, However, It can be provided at an appropriate position in an arbitrary path.

  As described above, the discharge gas refrigerant flowing into the evaporator 4 is bypassed in the refrigerant path of the evaporator 4 to exchange heat with the surrounding air at the portion where the defrosting of the evaporator 4 is completed. Not only can it be suppressed, but also an increase in the temperature of the evaporator 4 can be expected by reducing the flow resistance of the evaporator 4, so that the frost adhering to the evaporator 4 can be melted in a short time to further change the temperature in the room. It is possible to provide an air conditioner that can be reduced and that suppresses a decrease in comfort due to a decrease in room temperature.

  As described above, the refrigeration cycle apparatus according to the present invention not only reduces the amount of heat lost in the evaporator when bypassing the discharged refrigerant and defrosting the evaporator, but also the dynamic pressure component of the discharged refrigerant is a bypass pipe. Because the flow splitting ratio at the branch pipe part is greatly increased on the bypass pipe side, the influence of the flow path resistance of the refrigerant control device installed in the bypass pipe is reduced, thereby improving the design flexibility. Not only cost reduction but also a large amount of discharged refrigerant flows to the bypass pipe side, so the defrosting time can be shortened, so products using refrigeration cycles such as refrigerators and vending machines as well as air conditioners It can also be applied to applications.

Refrigerant system diagram of refrigeration cycle apparatus in Embodiment 1 of the present invention Refrigerant system diagram of refrigeration cycle apparatus in Embodiment 2 of the present invention Refrigerant system diagram of conventional air conditioner

Explanation of symbols

1 Compressor 1a Discharge Pipe 1b Suction Pipe 2 Condenser 3 Throttle Device 4 Evaporator 4a Inlet 4b Middle Inlet 4c Outlet 7 Indoor Blower 8 Outdoor Blower 9 Electric Heater 10 Evaporator Pipe 11 Four Way Valve 31 First Discharge Gas Bypass 32 Second 2 Discharge gas bypass 32a Flow rate adjustment pipe 32b Check valve 33 Third discharge gas bypass 33a Flow rate adjustment pipe 33b Check valve 34 Evaporator path bypass 34a Flow rate adjustment pipe 34b Check valve 40 Refrigerant control device 51 Branch pipes 52, 53, 54 T-tube

Claims (13)

A compressor, a four-way valve, a condenser, a throttling device, and an evaporator are connected in order by a pipe to form a refrigeration cycle, and from the discharge pipe of the compressor in the middle of the refrigerant flow path of the evaporator A first discharge refrigerant bypass for bypassing the discharge refrigerant, and a second discharge refrigerant bypass for bypassing the discharge refrigerant from the discharge pipe of the compressor to an evaporator pipe connecting the expansion device and the evaporator. A refrigeration cycle apparatus comprising a configuration in which discharged refrigerant flows through the two discharged refrigerant bypasses during defrosting in heating operation. A compressor, a four-way valve, a condenser, a throttling device, and an evaporator are connected in order by a pipe to form a refrigeration cycle, and from the discharge pipe of the compressor in the middle of the refrigerant flow path of the evaporator A refrigeration cycle apparatus comprising: a first discharge refrigerant bypass that bypasses the discharge refrigerant, and a configuration in which the discharge refrigerant flows through the first discharge refrigerant bypass during defrosting in heating operation. The refrigeration cycle apparatus according to claim 1 or 2, wherein a third discharge refrigerant bypass for bypassing the discharge refrigerant is provided in the suction pipe of the compressor. The flow rate of the refrigerant discharged from the compressor bypassing one or more discharged refrigerant bypasses is configured to be larger than the flow rate flowing to the four-way valve. The refrigeration cycle apparatus described. 5. The refrigeration cycle apparatus according to claim 4, wherein the overall flow path resistance on the discharge refrigerant bypass side is smaller than the flow path resistance on the condenser side. A branch pipe is provided in the discharge pipe, and the discharge refrigerant of the compressor is connected so that the dynamic pressure component acts more in the direction of the discharge refrigerant bypass than in the direction of the four-way valve. The refrigeration cycle apparatus according to claim 1. The discharge pipe is provided with a T-shaped branch pipe so that the discharge refrigerant of the compressor flows linearly in the direction of the discharge refrigerant bypass and bends in the direction of the four-way valve. The refrigeration cycle apparatus according to any one of? Among the at least one discharge refrigerant bypass outlet, a point where the outlet from the bypass merges with the piping of the refrigeration cycle is connected by a T-shaped tube so that the flow from the bypass becomes linear. The refrigeration cycle apparatus according to any one of claims. The refrigeration cycle apparatus according to any one of claims 1 to 8, wherein the pipe length of the longest discharge refrigerant bypass among the one or more discharge refrigerant bypasses is shorter than the pipe length on the condenser side. . The pipe diameter of the thickest discharge refrigerant bypass among the one or more discharge refrigerant bypasses is set to be equal to or greater than the pipe diameter on the condenser side. Refrigeration cycle equipment. The refrigeration cycle apparatus according to any one of claims 1 to 10, wherein 50% to 90% of the discharged refrigerant flows through one or more discharged refrigerant bypasses. An air conditioner comprising an indoor unit and an outdoor unit each having a blower, and the refrigeration cycle apparatus according to any one of claims 1 to 11. The air conditioner according to claim 12, wherein the indoor unit includes an auxiliary heating device.