JP3925426B2 - Refrigeration cycle equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigeration cycle apparatus suitable for vehicle air conditioning and the like.
[0002]
[Prior art]
The present applicant has previously proposed a refrigeration cycle apparatus in Patent Document 1 that adjusts the degree of superheat of the evaporator outlet gas refrigerant by a new method different from the conventional receiver cycle and accumulator cycle.
[0003]
Specifically, this prior art has the basic configuration of the refrigeration cycle shown in FIG. 7, and the first and second heat exchange units 5 and 6 are set in the condenser 2, and the first and second A gas-liquid separator 7 is disposed between the heat exchange units 5 and 6. Then, the main flow of the discharge gas refrigerant of the compressor 1 is caused to flow into the first heat exchange unit 5 to be condensed.
[0004]
A part of the liquid refrigerant condensed in the first heat exchange section 5 is caused to flow into the gas-liquid separator 7 through the liquid refrigerant bypass passage 9, and a part of the discharged gas refrigerant of the compressor 1 is supplied to the gas refrigerant bypass passage 10. The gas is branched and passes through the gas refrigerant bypass passage 10 so that part of the discharged gas refrigerant flows directly into the gas-liquid separator 7.
[0005]
The condensed liquid refrigerant and the discharged gas refrigerant are mixed and heat-exchanged in the gas-liquid separator 7, and the gas-liquid of the mixed refrigerant is separated by the density difference between the gas refrigerant and the liquid refrigerant. The gas refrigerant accumulates in the lower part in the separator 7, and the gas refrigerant accumulates in the upper part in the gas-liquid separator 7.
[0006]
The second heat exchange unit 6 is connected to the downstream side of the refrigerant flow of the first heat exchange unit 5, and the liquid refrigerant condensed in the first heat exchange unit 5 is disposed on the inlet side of the second heat exchange unit 6. The liquid refrigerant introduction passage 11 through which the main flow flows is connected. Further, the gas refrigerant return passage 12 and the liquid refrigerant return passage 13 of the gas-liquid separator 7 are connected to the inlet side of the second heat exchange unit 6.
[0007]
Accordingly, the main flow of the liquid refrigerant condensed in the first heat exchange unit 5, the gas refrigerant in the upper part in the gas-liquid separator 7, and the liquid refrigerant in the lower part in the gas-liquid separator 7 flow into the second heat exchange unit 6. These refrigerants are cooled again by the second heat exchanging unit 6 to be in a supercooled state. The supercooled liquid refrigerant is decompressed by the decompression device 3 to be in a low-pressure gas-liquid two-phase state, and after the low-pressure refrigerant evaporates in the evaporator 4, it is sucked into the compressor 1.
[0008]
In the above prior art, since the condensed liquid refrigerant and the discharge gas refrigerant are mixed and heat exchanged in the gas-liquid separator 7, the dryness of the mixed refrigerant changes according to the superheat degree of the compressor discharge gas refrigerant. Thus, the amount of liquid refrigerant accumulated in the gas-liquid separator 7 can be adjusted according to the degree of superheat of the compressor discharge gas refrigerant. Therefore, the circulation refrigerant flow rate in the cycle is adjusted by adjusting the amount of the liquid refrigerant in the gas-liquid separator 7, and as a result, the superheat degree of the discharge gas refrigerant of the compressor and consequently the superheat degree of the evaporator outlet gas refrigerant can be adjusted. .
[0009]
Thus, according to the prior art, the degree of superheat of the evaporator outlet gas refrigerant can be adjusted by adjusting the amount of liquid refrigerant in the gas-liquid separator 7 provided on the high-pressure side of the cycle. A variable throttle that responds to the state of the high-pressure refrigerant can be used. Therefore, there is an advantage that it is not necessary to use a temperature type expansion valve having a complicated structure and an expensive pressure reducing device. Further, since the gas-liquid separator 7 is provided on the high-pressure side of the cycle where the refrigerant specific volume is small, there are also advantages that the gas-liquid separator 7 can be reduced in size compared to the low-pressure side gas-liquid separator (accumulator).
[0010]
[Patent Document 1]
JP 2002-323274 A
[0011]
[Problems to be solved by the invention]
By the way, when the above-described prior art refrigeration cycle apparatus is actually prototyped and evaluated, the dimensional variation in the manufacture of the condenser 2, specifically, the passage area (hole) of the tube of the first heat exchange section 5 of the condenser 2. Adjustment of the amount of liquid refrigerant accumulated in the gas-liquid separator 7 under the influence of dimensional variations such as the diameter), the passage area (hole diameter) of the gas refrigerant bypass passage 10 and the passage area (hole diameter) of the liquid refrigerant bypass passage 9 As a result, there are cases where the circulating refrigerant flow rate in the cycle cannot be appropriately adjusted as intended according to the degree of superheat of the compressor discharge gas refrigerant.
[0012]
More specifically, in the above prior art, a part of the liquid refrigerant condensed in the first heat exchange section 5 is caused to flow into the gas-liquid separator 7 through the liquid refrigerant bypass passage 9 and the compressor 1 A part of the discharged gas refrigerant flows directly into the gas-liquid separator 7 through the gas refrigerant bypass passage 10. Here, regarding the ratio of the inflow amount of the liquid refrigerant to the gas-liquid separator 7 and the inflow amount of the discharge gas refrigerant (gas refrigerant bypass amount), the superheat degree of the discharge gas refrigerant is appropriately set in the gas-liquid separator 7. A predetermined ratio for feedback is obtained by experiment, and the inflow ratio of the liquid refrigerant and the discharge gas refrigerant is set to the predetermined ratio. For example, liquid refrigerant: discharged gas refrigerant = 1: 2 (weight flow rate ratio).
[0013]
However, if the ratio of the inflow amount of the liquid refrigerant to the gas-liquid separator 7 and the inflow amount of the discharge gas refrigerant deviates from a preset predetermined ratio due to the influence of the dimensional variation, for example, the inflow of the discharge gas refrigerant When the ratio of the amount decreases from a predetermined ratio, the superheat degree of the discharge gas refrigerant is considered to be smaller than the actual superheat degree, and the liquid refrigerant amount accumulated in the gas-liquid separator 7 increases excessively. As a result, the circulating refrigerant flow rate in the cycle becomes too small with respect to the degree of superheat of the discharged gas refrigerant, causing a reduction in cooling performance.
[0014]
In view of the above points, the present invention provides a refrigeration cycle apparatus that adjusts the flow rate of refrigerant circulating in a cycle by adjusting the amount of liquid refrigerant accumulated in a gas-liquid separator provided on the high-pressure side of the cycle. It aims at suppressing the deterioration of the adjustment effect | action of the circulating refrigerant | coolant flow rate in a cycle by influence.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the first heat exchange section (5) for radiating and condensing the discharged gas refrigerant of the compressor (1) and the first heat exchange section (5) are provided. A second heat exchange section (6) provided on the downstream side of the refrigerant flow, a gas-liquid separator (7) that separates the gas-liquid of the incoming refrigerant and stores the liquid refrigerant, and a discharge gas refrigerant of the compressor (1) Gas refrigerant bypass passage (10) that bypasses the first heat exchange section (5) and directly introduces it into the gas-liquid separator (7), and the liquid condensed through the first heat exchange section (5) A liquid refrigerant introduction passage (14) for introducing at least part of the refrigerant into the gas-liquid separator (7), and a gas for introducing the gas refrigerant in the gas-liquid separator (7) into the second heat exchange section (6). A refrigerant return passage (12), and adjusts the amount of liquid refrigerant accumulated in the gas-liquid separator (7) according to the degree of superheat of the refrigerant discharged from the compressor (1). In the refrigeration cycle apparatus, the gas refrigerant bypass passage (10), characterized in that it comprises a passage area adjusting means for adjusting the passage area (30).
[0016]
By the way, when a dimensional variation or the like in manufacturing of each part of the refrigerant passage of the first heat exchange part (5) occurs, this dimensional variation or the like appears as a change in pressure loss of the refrigerant passage of the first heat exchange part (5). Therefore, after the assembly of the condenser structure including the first heat exchange part (5) is completed, the passage area of the gas refrigerant bypass passage (10) is appropriate to correspond to the actual pressure loss of the refrigerant passage of the first heat exchange part (5). If the passage area adjusting means (30) is adjusted to an appropriate value, the influence of manufacturing dimensional variation and the like of each part of the refrigerant passage of the first heat exchange part (5) is eliminated, and the gas refrigerant bypass passage (10) is passed. The bypass amount of the gas refrigerant can be set to an appropriate amount. Therefore, it is possible to suppress the deterioration of the adjustment function of the circulating refrigerant flow rate in the cycle due to the influence of manufacturing dimensional variation and the like.
[0017]
Moreover, from this, it becomes possible to reduce the dimensional accuracy of each part of the refrigerant passage of the first heat exchanging part (5), thereby reducing the manufacturing cost of the condenser (2).
[0018]
As in the invention according to claim 2, in claim 1, the discharge gas refrigerant inlet part (24) of the compressor (1) is disposed on the first heat exchange part (5) side, and a gas refrigerant bypass passage ( 10) and the passage area adjusting means (30) may be arranged on the first heat exchange section (5) side.
[0019]
As in the third aspect of the present invention, in the first aspect, the inlet (24) of the discharged gas refrigerant of the compressor (1) is disposed on the gas-liquid separator (7) side, and the gas refrigerant bypass passage (10 ) And the passage area adjusting means (30) may be arranged on the gas-liquid separator (7) side.
[0020]
According to this, since the gas refrigerant bypass passage (10) and the passage area adjusting means (30) are arranged on the gas-liquid separator (7) side and are not brazed integrally with the condenser structure, the gas refrigerant bypass passage (10) The passage area does not change due to the brazing material wrapping around during brazing.
[0021]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the passage area adjusting means (30) is a valve element that adjusts the passage area of the gas refrigerant bypass passage (10) by being rotated. 30a).
[0022]
According to this, the adjustment operation of the passage area of the gas refrigerant bypass passage (10) can be performed by rotating the valve body (30a).
[0023]
According to a fifth aspect of the present invention, in the refrigeration cycle apparatus according to any one of the first to fourth aspects, the gas is directly introduced into the gas-liquid separator (7) through the gas refrigerant bypass passage (10). And adjusting the passage area so as to obtain a passage area corresponding to the measurement result of the pressure loss and a step of measuring the pressure loss of the refrigerant passage of the first heat exchange section (5) And adjusting the passage area of the gas refrigerant bypass passage (10) by means (30).
[0024]
By executing this adjustment method, it is possible to exhibit the “effect of suppressing the deterioration of the adjustment of the circulating refrigerant flow rate in the cycle due to the influence of manufacturing dimensional variation and the like” according to claim 1.
[0025]
In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is a basic configuration diagram of the refrigeration cycle apparatus according to the first embodiment, and shows a case where it is applied to a refrigeration cycle for vehicle air conditioning. 2 and 3 show a high-pressure side gas-liquid separator and a condenser according to the first embodiment.
[0027]
The compressor 1 is belt-driven by the vehicle engine E via the electromagnetic clutch 1a. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the condenser 2 from the inlet joint 24, where it is cooled and condensed by exchanging heat with the outside air. The condenser 2 is disposed at a portion that is cooled by the traveling wind generated by the vehicle traveling, specifically, the foremost portion in the vehicle engine room, and the blowing air from the traveling wind and the condenser cooling fan (not shown). It is cooled by.
[0028]
The decompression device 3 is for decompressing the refrigerant that has passed through the condenser 2 into a low-pressure gas-liquid two-phase state. In this example, the decompression device 3 is composed of a fixed throttle such as an orifice, a nozzle, or a capillary tube. Note that the decompression device 3 may be configured with a variable throttle whose opening degree is adjusted according to the state (pressure, temperature) of the high-pressure refrigerant.
[0029]
The evaporator 4 absorbs and evaporates the low-pressure refrigerant that has passed through the decompression device 3 from air blown from an air-conditioning blower (not shown). The evaporator 4 is disposed in a case of an air conditioning indoor unit (not shown), and the cold air cooled by the evaporator 4 is adjusted in temperature by a heater core (not shown) and blown out into the passenger compartment as is well known. The gas refrigerant evaporated in the evaporator 4 is sucked into the compressor 1.
[0030]
The condenser 2 includes a first heat exchange unit 5 and a second heat exchange unit 6 that are provided in the order of the refrigerant flow direction, and between the first heat exchange unit 5 and the second heat exchange unit 6. The gas-liquid separator 7 on the high-pressure side that performs gas-liquid separation of the refrigerant is installed.
[0031]
Between the gas-liquid separator 7 and the first heat exchange unit 5, there is a liquid refrigerant introduction passage 14 for introducing the entire amount of the condensed liquid refrigerant that has passed through the first heat exchange unit 5 into the gas-liquid separator 7. Is provided. Further, a part of the discharge gas refrigerant of the compressor 1 is branched into the gas refrigerant bypass passage 10, and the first heat exchange unit 5 is bypassed by the gas refrigerant bypass passage 10 so that a part of the discharge gas refrigerant is a gas-liquid separator. 7 is introduced directly. The gas refrigerant bypass passage 10 is provided with an adjustment valve 30 that forms passage area adjustment means.
[0032]
The condensed liquid refrigerant and the discharged gas refrigerant are mixed in the gas-liquid separator 7, the gas-liquid of the mixed refrigerant is separated by the density difference between the gas refrigerant and the liquid refrigerant, and the liquid refrigerant is stored in the gas-liquid separator 7. The gas refrigerant collects in the upper part of the gas-liquid separator 7.
[0033]
The second heat exchange unit 6 is connected to the downstream side of the refrigerant flow of the first heat exchange unit 5, and the gas refrigerant in the gas-liquid separator 7 is introduced to the inlet side of the second heat exchange unit 6. The gas refrigerant return passage 12 for performing the operation and the liquid refrigerant return passage 13 for introducing the liquid refrigerant in the gas-liquid separator 7 are connected.
[0034]
Next, the specific configurations of the condenser 2 and the gas-liquid separator 7 will be described with reference to FIGS. 2 and 3. The condenser 2 extends in the horizontal direction and includes a plurality of flat tubes 15 constituting a refrigerant flow path. The heat exchange part 8 is comprised with the corrugated fin 16 joined.
[0035]
The heat exchange unit 8 constitutes the first heat exchange unit 5 and the second heat exchange unit 6 as an integral structure. Header tanks (side tanks) 17 and 18 are arranged in the vertical direction on the left and right sides of the heat exchange unit 8 (first and second heat exchange units 5 and 6). The left and right ends of the flat tube 15 are joined to the header tanks 17 and 18, and the left and right ends of the refrigerant flow path in the flat tube 15 are communicated with the header tanks 17 and 18, respectively.
[0036]
Here, the internal space of one header tank 17 is partitioned into two spaces 17a, 17b, and 17c by upper and middle spaces by two partition plates 19a and 19b. The inner space of the other header tank 18 is partitioned into two upper and lower spaces 18 a and 18 b by a single partition plate 20.
[0037]
The lower partition plate 19b in one header tank 17 and the partition plate 20 in the other header tank 18 are arranged at the same height in the vertical direction of the tank. The upper side of both partition plates 19b and 20, that is, heat exchange. The first heat exchange unit 5 is configured in the upper region of the part 8, and the second heat exchange unit 6 is configured in the lower region of the partition plates 19 b and 20, that is, in the lower region of the heat exchange unit 8.
[0038]
An inlet joint 24 forming a refrigerant inlet is joined to a front wall surface of a portion of the header tank 17 corresponding to the intermediate space 17b, and a discharge-side refrigerant pipe of the compressor 1 is connected to the inlet joint 24. . An upper connection joint 17d is joined to a side wall surface of a portion corresponding to the upper space 17a and the intermediate space 17b in one header tank 17, and a portion corresponding to the lower space 17c in the one header tank 17 is further connected. A lower connection joint 17e is joined to the side wall surface.
[0039]
The upper connection joint 17d has two refrigerant passage portions 17g and 17h formed above and below the intermediate partition wall 17f as shown in an enlarged view in FIG. The lower refrigerant passage portion 17g communicates with the intermediate space 17b through a first communication hole 17i (FIG. 3) opened in the side wall surface of the header tank 17.
[0040]
For this reason, a part of the discharge gas refrigerant that has flowed into the intermediate space 17b from the inlet joint 24 passes through the first communication hole 17i and directly flows into the lower refrigerant passage portion 17g, and is opened in the intermediate partition wall 17f. A part of the discharged gas refrigerant flows into the upper refrigerant passage part 17h through the throttle hole 17j. Accordingly, in the specific examples of FIGS. 2 and 3, the gas refrigerant bypass passage 10 of FIG. 1 is configured by the first communication hole 17i, the lower refrigerant passage portion 17g, and the throttle hole 17j.
[0041]
The remaining portion of the discharge gas refrigerant that has flowed into the intermediate space 17b from the inlet joint 24 is the tube 15 group in the lower region of the first heat exchange unit 5 → the upper space 18a of the header tank 18 → the upper side of the first heat exchange unit 5. The tube 15 group in the region flows in a U-turn shape as indicated by an arrow a and condenses, and the condensed liquid refrigerant flows into the upper space 17 a of the header tank 17.
[0042]
Since the upper space 17a communicates with the upper refrigerant passage portion 17h of the upper connection joint 17d through a second communication hole 17k (FIG. 3) opened in the side wall surface of the header tank 17, the liquid refrigerant is secondly discharged from the upper space 17a. It passes through the communication hole 17k and flows into the upper refrigerant passage portion 17h. Accordingly, in the specific examples of FIGS. 2 and 3, the liquid refrigerant introduction passage 14 of FIG. 1 is configured by the upper space 17a and the second communication hole 17k.
[0043]
Further, the upper refrigerant passage portion 17h of the upper connection joint 17d is a portion where both the gas refrigerant from the throttle hole 17j and the liquid refrigerant from the second communication hole 17k flow in, and the two refrigerants are mixed together. The passage portion 17h constitutes a refrigerant gas-liquid mixing portion.
[0044]
The throttle hole 17j is a circular hole and constitutes the smallest passage area portion of the gas refrigerant bypass passage 10, so that the discharge gas bypass amount can be defined by the passage area of the throttle hole 17j. The upper connecting joint 17d is provided with a valve body 30a that can move in the direction of the through hole of the throttle hole 17j. The valve body 30a has a conical tip shape facing the throttle hole 17j, and is configured integrally with the male screw portion 30b. The male screw portion 30b is adapted to mesh with a female screw portion 30c formed on the lower wall surface of the upper connection joint 17d. Therefore, by rotating the valve body 30a using an appropriate tool, the conical tip of the valve body 30a can be inserted into and extracted from the throttle hole 17j. In the specific examples of FIGS. 2 and 3, the regulating valve 30 is configured by the valve body 30a, the male screw portion 30b, and the female screw portion 30c.
[0045]
The gas-liquid separator 7 includes a vertically long cylindrical tank body 70 extending in the vertical direction, and an upper lid member 71 and a lower lid member 72 that close the upper and lower opening ends of the tank body 70, and these members 70, 71. , 72 are joined together to form a space 73 for gas-liquid separation of the refrigerant.
[0046]
The upper lid member 71 is disposed so as to face the upper connection joint 17d of the header tank 17 and the lower lid member 72 is opposed to the lower connection joint 17e, and the upper lid member 71 and the lower lid are screwed by a screw means such as a bolt (not shown). The members 72 are fastened and fixed to the upper and lower connection joints 17d and 17e, respectively.
[0047]
Further, a refrigerant inlet passage 74 is formed in the upper lid member 71, and the refrigerant inlet passage 74 allows the upper passage portion (gas-liquid mixing portion) 17 h of the upper connection joint 17 d to communicate with the upper portion of the space 73. A refrigerant outlet passage 75 is formed in the lower lid member 72, and the refrigerant outlet passage 75 is formed in the header tank 17 via a passage portion 17m of the lower connection joint 17e and a third communication hole 17n opened in the side wall surface of the header tank 17. It communicates in the lower space 17c.
[0048]
With the above configuration, the gas-liquid separator 7 can be integrally assembled to the side wall surface of the header tank 17 with the upper and lower connection joints 17d and 17e interposed therebetween. At the same time, the refrigerant inlet passage 74 of the gas-liquid separator 7 is provided. Further, the passage connection between the refrigerant outlet passage 75 and the upper and lower spaces 17a and 17b of the header tank 17 can be completed. It should be noted that an elastic sealing material such as an O-ring (not shown) is interposed between the refrigerant inlet passage 74 and the refrigerant outlet passage 75 and the upper and lower connection joints 17d and 17e to ensure sealing performance. .
[0049]
Further, the internal space 73 of the gas-liquid separator 7 has a substantially circular cross section, and the refrigerant inlet passage 74 is arranged eccentrically from the center of the circular space 73 so that the refrigerant can be supplied from the refrigerant inlet passage 74 to the gas-liquid separator. 7 flows into the internal space from the tangential direction of the circular inner peripheral surface. Thereby, the inflowing refrigerant forms a swirling flow A in the upper region of the internal space 73 of the gas-liquid separator 7.
[0050]
Centrifugal force acts on the refrigerant flow by the swirling flow A, and the liquid refrigerant (saturated liquid) having a high density is pressed against the inner peripheral surface of the gas-liquid separator 7 and along the inner peripheral surface of the gas-liquid separator 7. It falls downward and accumulates in the lower part of the internal space 73 of the gas-liquid separator 7. Line B indicates the liquid level of the liquid refrigerant. On the other hand, the gas refrigerant (saturated gas) having a low density gathers near the center of the gas-liquid separator 7 and is located above the internal space 73 of the gas-liquid separator 7, that is, above the liquid level B of the liquid refrigerant. An area for the gas refrigerant is formed.
[0051]
As described above, the gas-liquid of the inflowing refrigerant from the refrigerant inlet passage 74 is forcibly separated by utilizing the centrifugal force of the swirling flow A. Therefore, even if the tank volume of the gas-liquid separator 7 is small, the gas-liquid of the inflowing refrigerant Can be reliably separated. As described above, the centrifugal separator is configured in the vicinity of the refrigerant inlet passage 74 in the upper part of the gas-liquid separator 7.
[0052]
A round pipe-shaped tubular member 76 is arranged in the center of the circular internal space 73 of the gas-liquid separator 7 so as to extend in the vertical direction. The upper end portion of the tubular member 76 is supported and fixed to the upper lid member 71, and the lower end portion is inserted into the upper end opening of the refrigerant outlet passage 75 of the lower lid member 72 and supported and fixed to the lower lid member 72.
[0053]
And the gas return port 76a which suck | inhales a gas refrigerant is opening to the site | part sufficiently upper than the liquid level B of the liquid refrigerant among the outer peripheral surfaces of the tubular member 76. As shown in FIG. The gas refrigerant flows from the gas return port 76 a through the internal flow path of the tubular member 76 to the refrigerant outlet passage 75. Accordingly, the gas refrigerant return passage 12 of FIG. 1 is configured by the gas return port 76a and the like.
[0054]
In addition, a liquid return port 76b for sucking the liquid refrigerant is opened in a portion of the outer peripheral surface of the tubular member 76 that is sufficiently below the liquid level B of the liquid refrigerant, and the liquid refrigerant passes through the liquid return port 76b. The refrigerant is sucked into the internal flow path 76, mixed with the flow of the gas refrigerant, and flows into the refrigerant outlet passage 75. Accordingly, the liquid refrigerant return passage 13 of FIG. 1 is configured by the liquid return port 76b and the like. A desiccant 77 for adsorbing moisture contained in the refrigerant flow is disposed in the internal space 73 of the gas-liquid separator 7.
[0055]
The refrigerant flowing from the refrigerant outlet passage 75 of the gas-liquid separator 7 through the passage portion 17m of the lower connection joint 17e and the third communication hole 17n of the header tank 17 into the lower space 17c of the header tank 17 is second heat. After passing through the flat tube 15 of the exchange unit 6, it again radiates heat into the outside air to be in a supercooled state, and flows into the lower space 18 b of the other header tank 18. An outlet joint 25 that forms a refrigerant outlet is joined to the lower portion of the other header tank 18, and the refrigerant in the lower space 18 b goes out of the condenser 2 from the outlet joint 25 toward the decompression device 3.
[0056]
In addition, the tube 15, the corrugated fin 16, the header tanks 17 and 18, the connection joints 17d and 17e, the inlet joint 24, and the outlet joint 25 of the heat exchange part 8 (first and second heat exchange parts 5 and 6) of the condenser 2 Etc. are all made of aluminum material and assembled into an integral structure by brazing.
[0057]
Next, the operation of the first embodiment in the above configuration will be described. The discharge gas refrigerant of the compressor 1 flows into the intermediate space 17 b of the header tank 17 from the inlet joint 24. This inflowing refrigerant is branched into a refrigerant flow toward the first heat exchanging part 5 and a refrigerant flow directly bypassing the first heat exchanging part 5 and directed toward the upper connection joint 17d.
[0058]
A part of the discharge gas refrigerant flows in a U-turn shape from the intermediate space 17b through the first heat exchange part 5 as indicated by an arrow a. During this time, the discharge gas refrigerant dissipates heat into the outside air and condenses. Accordingly, the condensed liquid refrigerant passes through the upper space 17a of the header tank 17 and the second communication hole 17k and flows into the upper refrigerant passage portion 17h of the upper connection joint 17d.
[0059]
On the other hand, the remaining portion of the discharge gas refrigerant flows directly from the intermediate space 17b through the first communication hole 17i, the lower refrigerant passage portion 17g, and the throttle hole 17j and directly into the upper refrigerant passage portion 17h. Accordingly, the entire amount of the condensed liquid refrigerant that has passed through the first heat exchange unit 5 and the bypass discharge gas refrigerant from the throttle hole 17j are mixed in the upper refrigerant passage portion 17h, and this mixed refrigerant is mixed with the gas-liquid separator 7. Into the refrigerant inlet passage 74.
[0060]
A swirling flow A is formed in the refrigerant flow flowing from the refrigerant inlet passage 74 into the upper portion of the internal space 73 of the gas-liquid separator 7, and the gas-liquid refrigerant is liquid refrigerant (saturated liquid) and gas refrigerant by the above-described centrifugal separation. (Saturated gas). The liquid refrigerant falls downward in the gas-liquid separator 7 and accumulates in the lower part of the gas-liquid separator 7.
[0061]
A part of the liquid refrigerant flows into the tubular member 76 from the liquid return port 76b near the lower end of the tubular member 76. Further, the gas refrigerant accumulated in the upper part of the gas-liquid separator 7 flows into the tubular member 76 from the gas return port 76a. The opening area of the liquid return port 76b is made sufficiently smaller than the opening area of the gas return port 76a to limit the amount of liquid refrigerant flowing into the liquid return port 76b to a very small amount.
[0062]
The gas refrigerant and the liquid refrigerant flowing into the tubular member 76 flow into the lower space 17c of the header tank 17 through the refrigerant outlet passage 75 → the passage hole 17m of the lower connection joint 17e and the third communication hole 17n of the header tank 17. To do.
[0063]
The gas refrigerant (saturated gas) and the liquid refrigerant (saturated liquid) are mixed in the path, and then pass through the flat tube 15 of the second heat exchanging unit 6 and again dissipate heat into the atmosphere to be supercooled. It becomes a state. The supercooled liquid refrigerant flows into the lower space 18b of the header tank 18, and then exits the condenser 2 from the outlet joint 25 and travels toward the decompression device 3 side.
[0064]
A part of the liquid refrigerant accumulated in the gas-liquid separator 7 is introduced into the second heat exchange unit 6 from the liquid return port 76b, and a part of the liquid refrigerant is always returned into the flow of the cycle circulation refrigerant, thereby becoming the liquid refrigerant. The contained lubricating oil can be reliably returned to the compressor 1 to ensure the lubricity of the compressor 1.
[0065]
By the way, in order to form the refrigerant flow as described above, the entire amount of the liquid refrigerant condensed through the first heat exchange section 5 and a part of the gas refrigerant discharged from the inlet joint 24 are the upper refrigerant passage of the upper connection joint 17d. Mix in part 17h and heat exchange. Thereby, the refrigerant flowing into the gas-liquid separator 7 from the upper space 17a is in a gas-liquid two-phase state having a dryness corresponding to the degree of superheat of the compressor discharge gas refrigerant.
[0066]
As a result, the amount of liquid refrigerant accumulated in the gas-liquid separator 7 becomes an amount corresponding to the degree of superheat of the compressor discharge gas refrigerant. In other words, the amount of liquid refrigerant in the gas-liquid separator 7 can be adjusted in response to a change in the degree of superheat of the compressor discharge gas refrigerant. By adjusting the amount of the liquid refrigerant, the amount of gas refrigerant introduced from the gas-liquid separator 7 to the second heat exchange unit 6 can be changed to adjust the flow rate of the refrigerant circulating in the cycle. The degree of superheat can be adjusted. Since the compression process in the compressor 1 is basically an isentropic change, if the superheat degree of the compressor 1 discharge gas refrigerant can be controlled, the superheat degree of the evaporator outlet gas refrigerant can be controlled.
[0067]
As described above, in the refrigeration cycle apparatus that adjusts the amount of liquid refrigerant accumulated in the gas-liquid separator 7 provided on the high-pressure side of the cycle and adjusts the flow rate of refrigerant circulating in the cycle, the gas refrigerant bypass passage 10 (first communication hole) 17i, the discharge gas bypass amount directly introduced into the gas-liquid separator 7 from the lower refrigerant passage portion 17g, the throttle hole 17j), and the gas-liquid from the liquid refrigerant introduction passage 14 (upper space 17a, second communication hole 17k). Maintaining the inflow ratio with the liquid refrigerant amount after passing through the first heat exchanging section 5 introduced into the separator 7 at a predetermined set ratio, the adjustment of the circulating refrigerant flow rate in the cycle, and thus the degree of superheat of the refrigerant This is particularly important for ensuring control performance.
[0068]
However, as already described in the column “Problems to be Solved by the Invention”, the inflow ratio between the discharge gas bypass amount and the liquid refrigerant amount is condensed due to the influence of the dimensional variation of each part and the wrapping of the brazing material at the time of brazing. It changes from a predetermined set ratio in the manufacturing process of the vessel 2, and deteriorates the superheat degree control performance of the refrigerant.
[0069]
Therefore, in this embodiment, the discharge gas bypass amount is accurately defined by the following adjustment method, so that the inflow ratio between the discharge gas bypass amount and the liquid refrigerant amount is accurately maintained at the predetermined set ratio. ing.
[0070]
FIG. 4 shows a state of the condenser alone after the integral brazing process of the condenser 2 is finished and the production of the condenser 2 is finished, and before the gas-liquid separator 7 is assembled to the condenser 2. In this single condenser state, first, the pressure loss of the refrigerant passage of the first heat exchange unit 5 of the condenser 2 is measured.
[0071]
In measuring the pressure loss of the refrigerant passage of the first heat exchange unit 5, first, the valve body 30a of the adjustment valve 30 is rotated with an appropriate tool to set the valve body 30a to the fully closed position of the throttle hole 17j. In this state, the pressure measurement pipes 31 and 32 are connected to the upper passage portion 17h of the inlet joint 24 and the upper connection joint 17d, respectively. The pressure measurement pipes 31 and 32 are respectively connected to the inlet of the first heat exchange unit 5. A side pressure measurement point 31a and an outlet side pressure measurement point 32a are set.
[0072]
A fluid pressure device that supplies a fluid of a predetermined pressure (not shown), specifically a pneumatic device, is connected to the pressure measurement piping 31 on the inlet side, and the pressure measurement piping 32 on the outlet side is open to the atmosphere. Air of a predetermined pressure is supplied from the pneumatic device to the refrigerant passage of the first heat exchanging unit 5, and the pressure P1 at the inlet side pressure measuring point 31a and the pressure P2 at the outlet side pressure measuring point 32a of the first heat exchanging unit 5 are set. taking measurement.
[0073]
The pressure loss ΔP (= P1−P2) of the refrigerant passage of the first heat exchange unit 5 is calculated from the measured pressure P1 and the measured pressure P2. The pressure loss ΔP indicates a value reflecting the influence of the dimensional variation of each part of the condenser 2 and the brazing material wraparound.
[0074]
Then, the passage area of the throttle hole 17j necessary for maintaining the inflow ratio between the discharge gas bypass amount and the liquid refrigerant amount at the predetermined set ratio, that is, the predetermined set value of the valve body 30a of the adjustment valve 30; The relationship with the pressure loss ΔP is calculated in advance. Here, the desired set value of the valve body 30a is the amount of rotation from the fully closed position of the valve body 30a.
[0075]
Accordingly, when the valve body 30a of the regulating valve 30 is rotated from the fully closed position by the amount of rotation corresponding to the actual pressure loss ΔP value, and the valve body 30a is positioned at the desired set value corresponding to the pressure loss ΔP value, The passage area of the hole 17j can be automatically set to an appropriate value in consideration of the influence of dimensional variation, brazing material wraparound, and the like. As a result, the inflow ratio between the discharge gas bypass amount and the liquid refrigerant amount can be maintained at the desired set ratio without being affected by dimensional variation or brazing material wrapping, and the superheat control performance of the refrigerant can be demonstrated well. it can.
[0076]
In addition, the valve body 30a is reliably fixed with respect to the upper connection joint 17d so that the rotational position of the predetermined set value of the valve body 30a does not change after use of the refrigeration cycle apparatus.
[0077]
(Second Embodiment)
In the first embodiment, the discharge gas inlet joint 24 is disposed in the header tank 17 of the condenser 2, and the gas refrigerant bypass passage 10 (first communication hole 17i, lower refrigerant passage portion 17g, throttle hole 17j) and the gas refrigerant. The adjusting valve 30 for adjusting the passage area of the throttle hole 17j of the bypass passage 10 is disposed on the condenser 2 side. In the second embodiment, as shown in FIGS. 5 and 6, the discharge gas inlet joint 24 is provided. Is arranged on the gas-liquid separator 7 side, and the gas refrigerant bypass passage 10 and the regulating valve 30 are both arranged on the gas-liquid separator 7 side.
[0078]
5 and 6, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The parts different from the first embodiment will be specifically described below.
[0079]
A circular upper opening 70a is formed in the upper wall of the tank body 70 of the gas-liquid separator 7, and the cylindrical protrusion 24a of the refrigerant inlet joint 24 is fitted into the upper opening 70a. An O-ring 24b is mounted as an elastic seal material on the outer peripheral groove of the cylindrical protrusion 24a, and the space between the cylindrical protrusion 24a and the inner peripheral wall surface of the upper opening 70a is sealed by the O-ring 24b.
[0080]
The refrigerant inlet joint 24 is fastened and fixed to the upper surface wall portion of the tank body 70 by a bolt (not shown). The refrigerant inlet joint 24 has a passage hole 24c penetrating in the axial direction (vertical direction) of the cylindrical protrusion 24a, and the discharged gas refrigerant of the compressor 1 passes through the passage hole 24c to be an inner space of the upper opening 70a. Flow into.
[0081]
A ring-shaped plate portion 70b is formed at a position below the upper end surface of the upper opening portion 70a by a predetermined dimension so as to protrude inward of the inner space of the upper opening portion 70a, and a through-hole is formed at the center of the ring-shaped plate portion 70b. Is opened to form a gas refrigerant bypass passage 10. The discharge gas bypass passage 10 divides a part of the discharge gas refrigerant that has flowed into the inner space of the upper opening 70a and directly flows (bypass) it into the gas-liquid separation space 73 side. The gas refrigerant bypass amount to the gas-liquid separation space 73 side can be defined by the passage area (hole opening area).
[0082]
The gas refrigerant bypass passage 10 is provided with an adjustment valve 30 (FIG. 6) for adjusting the passage area. The adjusting valve 30 has a rotary valve structure using a cylindrical valve body 30a, and a through hole 30d penetrating in the radial direction is formed in the valve body 30a. As shown in FIG. 6, a cylindrical fitting hole 70c is formed in the ring-shaped plate portion 70b in a direction perpendicular to the passage direction (vertical direction) of the gas refrigerant bypass passage 10 (horizontal direction). A cylindrical valve body 30a is rotatably fitted in the hole 70c as indicated by an arrow C.
[0083]
A rotary shaft (not shown) is integrally provided at the end of the valve body 30a in the axial direction (perpendicular to the plane of FIG. 6). The rotary shaft protrudes outside the tank main body 70, and the rotary shaft causes the tank main body 70 to move. The valve body 30a can be rotated from the outside. Between the rotating shaft and the fitting hole portion of the tank main body 70, an airtightness is maintained using an elastic seal material such as an O-ring.
[0084]
Of the upper side wall portion 70d of the tank body 70, a cylindrical shape projecting toward the one header tank 17 side of the condenser 2 at the upper side (upstream side) portion and the lower side (downstream side) portion of the discharge gas bypass passage 10, respectively. The protrusions 70e and 70f are integrally formed. A condensing discharge gas passage 78 is formed by making a through hole in the central portion of the upper cylindrical protruding portion 70e of both the cylindrical protruding portions 70e and 70f.
[0085]
The discharge gas is distributed to the condensing discharge gas passage 78 and the discharge gas bypass passage 10. In this embodiment, the discharge gas is discharged to the discharge gas bypass passage 10 more than the distribution amount of the discharge gas to the condensing discharge gas passage 78. The amount of gas distribution is increased.
[0086]
In addition, the liquid refrigerant introduction passage 14 is formed by making a through hole in the central portion of the cylindrical projection 70 f on the lower side of the cylindrical projections 70 e and 70 f. This liquid refrigerant introduction passage 14 introduces the entire amount of the liquid refrigerant condensed in the first heat exchanging section 5 of the condenser 2 into the gas-liquid mixing section 73a immediately below the discharge gas bypass passage 10 in the space 73 in the tank body 70. To do. This gas-liquid mixing part 73a corresponds to the upper passage part 17h forming the gas-liquid mixing part in the first embodiment.
[0087]
O-rings 70g and 70h are mounted as elastic sealing materials on the circumferential grooves in the circumferential direction of both cylindrical protrusions 70e and 70f, respectively.
[0088]
The connection joint 17p is made of a metal such as aluminum and is joined to one header tank 17 of the condenser 2 by brazing. The connection joint 17p is formed with circular passage holes 17q and 17r for fitting both cylindrical protrusions 70e and 70f of the tank body 70.
[0089]
The passage holes 17q and 17r of the connection joint 17p and the cylindrical protrusions 70e and 70f are sealed with O-rings 70g and 70h. The tank body 70 is fastened and fixed to the connection joint 17p by a bolt (not shown).
[0090]
Circular fitting projections 17 s and 17 t are formed on the end face of the connection joint 17 p on the header tank 17 side corresponding to the passage holes 17 q and 17 r, respectively. The fitting projections 17 s and 17 t are fitted to the header tank 17. The connection joint 17p is joined to the header tank 17 in a state of being fitted into the hole.
[0091]
Thereby, the upper space 17a of one header tank 17 of the condenser 2 is communicated with the condensing discharge gas passage 78 of the gas-liquid separator 7 through the upper passage hole 17q of the connection joint 17p. Further, the intermediate space 17b of the header tank 17 communicates with the liquid refrigerant introduction passage 14 of the gas-liquid separator 7 through the lower passage hole 17r of the connection joint 17p.
[0092]
Accordingly, a part of the refrigerant gas discharged from the upper opening 70 a of the gas-liquid separator 7 flows from the condensing discharge gas passage 78 through the upper passage hole 17 q into the upper space 17 a of the header tank 17. Further, the condensed liquid refrigerant in the intermediate space 17b of the header tank 17 passes through the lower passage hole 17r and the liquid refrigerant introduction passage 14 and flows into the gas-liquid mixing portion 73a.
[0093]
A return refrigerant inlet joint 23 that forms an inlet portion of the return refrigerant from the gas-liquid separator 7 is joined to a portion of the header tank 17 corresponding to the lower space 17c. The return refrigerant inlet joint 23 connects the connection pipe 23a. To the connection joint 79 at the bottom of the gas-liquid separator 7.
[0094]
The connection joint 79 is sealed and fixed to a central hole portion 72a opened in the lower lid member 72 of the gas-liquid separator 7 via an O-ring 79a as an elastic seal material. The center hole 72a corresponds to the refrigerant outlet passage of the first embodiment.
[0095]
On the other hand, the lower end portion of the tubular member 76 in the gas-liquid separator 7 is supported and fixed in the central hole portion 72 a of the lower lid member 72. As a result, the lower end portion of the internal passage of the tubular member 76 communicates with the passage hole 79 a of the connection joint 79. The upper end portion of the tubular member 76 is located at a position sufficiently above the liquid level A of the stored liquid refrigerant in the gas-liquid separator 7 and constitutes a closed end surface.
[0096]
The refrigerant mixed in the gas-liquid mixing unit 73a is centrifuged by the swirling flow A, and the liquid refrigerant is collected in the lower portion of the space 73 in the gas-liquid separator 7, and a gas refrigerant region is formed above the liquid refrigerant. .
[0097]
The gas refrigerant and the liquid refrigerant in the gas-liquid separator 7 flow into the tubular member 76 from the gas return port 76a and the liquid return port 76b, and this inflow refrigerant flows from the tubular member 76 to the connection joint 79, the connecting pipe 23a, It flows into the lower space 17 c of the header tank 17 through the return refrigerant inlet joint 23.
[0098]
In short, in the second embodiment, the discharge gas inlet joint 24 is arranged on the gas-liquid separator 7 side, and the discharge gas is distributed to the gas-liquid separator 7 side and the first heat exchange unit 5 side of the condenser 2. Although the mechanism is arranged inside the gas-liquid separator 7, the circulating refrigerant flow rate adjusting action in the cycle can be performed in the same manner as in the first embodiment.
[0099]
Then, in a state before the gas-liquid separator 7 is assembled to the condenser 2 side, that is, in a state where the integral brazing of the condenser 2 is finished, the method of the first heat exchange unit 5 is performed by the method described in the first embodiment. The inlet side pressure P1 and the outlet side pressure P2 are measured, and the pressure loss ΔP (= P1−P2) of the refrigerant passage of the first heat exchanging part 5 is calculated from the measured pressures P1 and P2, and adjusted based on the pressure loss ΔP. An initial set value (the amount of rotation from the fully closed position of the valve body 30a) of the valve body 30a of the valve 30 is determined, and the valve body 30a is rotated so as to be at the position of the initial set value.
[0100]
As a result, the inflow ratio between the discharge gas bypass amount and the liquid refrigerant amount can be maintained at a predetermined set ratio without being affected by dimensional variation or wraparound of the brazing material, and the refrigerant can be overheated as in the first embodiment. Degree control performance can be demonstrated well.
[0101]
When the gas refrigerant bypass passage 10 is integrally formed on the connection joint 17d side of the condenser 2 as in the first embodiment, the brazing material is in the gas refrigerant bypass passage 10 when the condenser 2 is integrally brazed. In the second embodiment, since the gas refrigerant bypass passage 10 is configured in the gas-liquid separator 7, the passage area of the gas refrigerant bypass passage 10 is not reduced by the brazing material. .
(Other embodiments)
In the first and second embodiments, the entire amount of the liquid refrigerant that has passed through the first heat exchange unit 5 is caused to flow into the gas-liquid separator 7, but the first heat is the same as in the prior art of FIG. Only a part of the liquid refrigerant that has passed through the exchange unit 5 is allowed to flow into the gas-liquid separator 7, and the remaining part of the liquid refrigerant that has passed through the first heat exchange unit 5 is the inlet side of the second heat exchange unit 6 (specifically, It may be allowed to flow into the lower space 17c) of the header tank 17.
[Brief description of the drawings]
FIG. 1 is a basic configuration diagram of a refrigeration cycle according to a first embodiment of the present invention.
FIG. 2 is a schematic longitudinal sectional view showing a gas-liquid separator integrated condenser according to the first embodiment.
3 is an enlarged cross-sectional view of a main part of FIG.
FIG. 4 is a cross-sectional view of a single condenser according to the first embodiment and shows a method for measuring pressure loss in the refrigerant passage of the first heat exchange unit 5;
FIG. 5 is a schematic longitudinal sectional view showing a gas-liquid separator integrated condenser according to a second embodiment.
6 is an enlarged cross-sectional view of a main part of FIG.
FIG. 7 is a basic configuration diagram of a refrigeration cycle according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Condenser, 3 ... Depressurizer, 4 ... Evaporator, 5 ... 1st heat exchange part,
6 ... 2nd heat exchange part, 7 ... Gas-liquid separator, 10 ... Gas refrigerant bypass passage,
10a ... Discharge gas refrigerant throttle, 12 ... Gas refrigerant return passage,
13 ... Liquid refrigerant return passage, 14 ... Liquid refrigerant introduction passage,
30 ... Adjusting valve (passage area adjusting means).

Claims (5)

A first heat exchange section (5) for radiating and condensing the discharged gas refrigerant of the compressor (1);
A second heat exchange section (6) provided on the downstream side of the refrigerant flow of the first heat exchange section (5);
A gas-liquid separator (7) for separating the gas-liquid of the inflowing refrigerant and storing the liquid refrigerant;
A gas refrigerant bypass passage (10) for directly introducing a part of the discharged gas refrigerant of the compressor (1) into the gas-liquid separator (7), bypassing the first heat exchange section (5), A liquid refrigerant introduction passage (14) for introducing at least a part of the liquid refrigerant condensed through the first heat exchange section (5) into the gas-liquid separator (7);
A gas refrigerant return passage (12) for introducing the gas refrigerant in the gas-liquid separator (7) into the second heat exchange section (6),
In the refrigeration cycle apparatus for adjusting the amount of liquid refrigerant accumulated in the gas-liquid separator (7) according to the degree of superheat of the discharge gas refrigerant of the compressor (1),
A refrigeration cycle apparatus comprising a passage area adjusting means (30) for adjusting a passage area in the gas refrigerant bypass passage (10). The inlet (24) of the discharge gas refrigerant of the compressor (1) is disposed on the first heat exchange part (5) side, and the gas refrigerant bypass passage (10) and the passage area adjusting means (30) are It arrange | positions at the 1st heat exchange part (5) side, The refrigeration cycle apparatus of Claim 1 characterized by the above-mentioned. The inlet (24) of the discharge gas refrigerant of the compressor (1) is disposed on the gas-liquid separator (7) side, and the gas refrigerant bypass passage (10) and the passage area adjusting means (30) are connected to the gas refrigerant. It arrange | positions at the liquid separator (7) side, The refrigeration cycle apparatus of Claim 1 characterized by the above-mentioned. The said passage area adjustment means (30) has a valve body (30a) which is rotated and adjusts the passage area of the said gas refrigerant bypass passage (10), Any one of Claim 1 thru | or 3 characterized by the above-mentioned. The refrigeration cycle apparatus according to any one of the above. The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein a gas refrigerant bypass amount that is directly introduced into the gas-liquid separator (7) through the gas refrigerant bypass passage (10) is adjusted. An adjustment method,
Measuring the pressure loss of the refrigerant passage of the first heat exchange section (5);
Adjusting the passage area of the gas refrigerant bypass passage (10) by the passage area adjusting means (30) so that a passage area corresponding to the measurement result of the pressure loss is obtained. How to adjust the amount.

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