WO2014192114A1 - スクリュー圧縮機及び冷凍サイクル装置 - Google Patents
スクリュー圧縮機及び冷凍サイクル装置 Download PDFInfo
- Publication number
- WO2014192114A1 WO2014192114A1 PCT/JP2013/065000 JP2013065000W WO2014192114A1 WO 2014192114 A1 WO2014192114 A1 WO 2014192114A1 JP 2013065000 W JP2013065000 W JP 2013065000W WO 2014192114 A1 WO2014192114 A1 WO 2014192114A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- discharge
- port
- screw
- slide valve
- economizer
- Prior art date
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
- F04C18/14—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
- F04C18/16—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/48—Rotary-piston pumps with non-parallel axes of movement of co-operating members
- F04C18/50—Rotary-piston pumps with non-parallel axes of movement of co-operating members the axes being arranged at an angle of 90 degrees
- F04C18/52—Rotary-piston pumps with non-parallel axes of movement of co-operating members the axes being arranged at an angle of 90 degrees of intermeshing engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/10—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by changing the positions of the inlet or outlet openings with respect to the working chamber
- F04C28/12—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by changing the positions of the inlet or outlet openings with respect to the working chamber using sliding valves
Definitions
- the present invention relates to a screw compressor and a refrigeration cycle apparatus used in a refrigeration cycle for refrigeration and air conditioning.
- a columnar slide valve that slides in the direction of the rotation axis of the screw rotor on the outer periphery of the screw rotor, one end of which is a fluid suction side and the other end is a discharge side (for example, , Patent Literature 1, Patent Literature 2, Patent Literature 3, and Patent Literature 4).
- the slide valve changes the discharge start (compression completion) position of the high-pressure gas compressed in the compression chamber, and changes the ratio of the discharge volume to the suction volume by changing the discharge area.
- the slide stop position of the slide valve is controlled so as to obtain a volume ratio at which high compressor efficiency is obtained with respect to the compression ratio (discharge pressure / suction pressure) corresponding to the operating load. That is, the position of the slide valve is changed depending on whether the operation state is full load operation or partial load operation. Specifically, the slide valve is positioned on the suction side to increase the opening of the discharge port during partial load operation, and is positioned on the discharge side to reduce the opening of the discharge port during full load operation. , The position changes.
- the discharge port of the screw compressor of patent document 1 is formed by the inner wall surface of the opening part provided in the casing which accommodates a screw rotor, and the discharge side end surface of a slide valve, and has a variable port and a fixed port.
- the variable port is a port whose area changes when the closed portion by the slide valve is opened by movement of the slide valve or the open portion is closed by movement in the reverse direction.
- the fixed port is provided between the variable port and an opening in which the gate rotor teeth are inserted in the casing (hereinafter referred to as gate rotor opening), and is always open regardless of the position of the slide valve. Port.
- a plurality of sub-ports are provided for the purpose of expanding the discharge area during partial load operation.
- the plurality of sub-ports are formed in a parallelogram shape, and are arranged in parallel on the suction side of the fixed port between the variable port and the gate rotor opening.
- the fixed port is formed so as to secure a discharge area according to the position of the slide valve during full load operation.
- the sub port communicates with the compression chamber and the variable port in partial load operation where the slide valve slides to the suction side, and is fixed to the fixed port so that it is closed by the slide valve in full load operation where the slide valve slides to the discharge side.
- Patent Document 1 by providing the fixed port and the sub port as described above, the compression chambers having different pressures are prevented from communicating with each other, and a sufficiently large discharge area is ensured in the partial load operation state. It is possible to do.
- a sub port is provided in addition to the variable port and the fixed port for the purpose of securing a discharge area at a partial load.
- the subport of this Patent Document 2 is provided on the counter-rotating side of the screw rotor with respect to the slide valve, and the compression chamber is set to the discharge side space of the screw rotor during partial load operation of 50% to 75% with respect to the full load. I try to communicate.
- Patent Document 3 the inclination of the discharge-side end face of the slide valve is matched to the inclination of the screw groove at the discharge start time of the partial load operation, and the efficiency of the partial load operation is given priority over the efficiency of the full load operation.
- a screw compressor is disclosed.
- the slide valve is connected to the guide portion via a rod-like connecting portion, and can be slid by being driven by a drive mechanism. Since the connecting portion is disposed across the discharge port, the connection portion blocks the flow path of the discharge fluid. For this reason, it becomes a factor which reduces a flow-path area and increases discharge pressure loss.
- Patent Document 4 discloses a technique in which the connecting portion is arranged so as to be biased toward the counter-rotating direction side of the variable port so as not to block the discharge flow path as much as possible.
- Japanese Patent Laying-Open No. 2011-132934 page 11, FIG. 6) JP 2011-32957 A ([0033], FIG. 2) Japanese Patent No. 4735757 (page 12, FIG. 6) Japanese Patent No. 3214100 ([0020], FIG. 3)
- the coefficient of performance (capacity / power consumption) under rated conditions has been mainly used as an energy saving index of a refrigerator equipped with a screw compressor.
- an index close to actual driving conditions, for example, a period performance coefficient IPLV (Integrated Part Load Value) determined in the United States has been attracting attention.
- the operating time at rated conditions throughout the year is very short, and more than 90% of the operating time throughout the year is operated with partial load.
- the partial load is mostly operated at 75 to 50% of the total load.
- the refrigerant circulation flow rate and the operation compression ratio are different, and the coefficient of performance also changes.
- the period performance coefficient has been attracting attention. That is, the period coefficient of performance is an index that emphasizes the coefficient of performance under partial load conditions.
- the screw compressors described in Patent Document 1 and Patent Document 2 adopt the above-described configuration in order to increase the discharge area under the partial load condition in order to improve the efficiency of the partial load condition. . That is, in addition to the conventional variable port, a sub port communicating with the discharge side space only in the partial load operation is provided.
- the secondary port since the secondary port is provided so as to communicate with the compression chamber in the middle of compression at full load operation, it becomes a volume part (dead volume) that is wastedly compressed from the suction pressure to the discharge pressure, and causes loss It has become.
- the screw compressor described in Patent Document 3 has a discharge area at the time of discharge start under the partial load condition. Can be secured sufficiently, and the operation efficiency is improved.
- the discharge side end face of the slide valve does not follow the inclination of the screw groove at the start of discharge under the full load condition. For this reason, due to the difference in inclination, the discharge area at the start of discharge when adjusting the inclination of the screw groove during partial load operation is smaller than when adjusting the inclination of the screw groove during full load operation. There is a problem that the pressure loss increases and the efficiency decreases.
- connection part is on a variable port both at the time of full load operation and partial load operation. There is no change. For this reason, the problem that the discharge flow path is blocked by the connecting portion and the discharge pressure loss increases still remains, and improvement of the reduction in operation efficiency by the connecting portion is demanded.
- the screw compressors of Patent Document 1 to Patent Document 4 have, for example, the opening of the gate rotor at the center of the slide valve so as to ensure a variable port area when performing mechanical displacement control with a pair of slide valves.
- the mechanical capacity control means that the slide valve is moved to the discharge side and a bypass port (opening that allows the screw groove on the suction side to communicate with the low pressure space) is opened, thereby delaying the compression start timing and controlling the capacity. This is the control to be performed.
- a partition wall that partitions suction pressure and discharge pressure.
- the positional relationship between the slide valve and the bulkhead is set so that when the slide valve is moved to the suction side according to the discharge start point in the low compression ratio operation, the discharge-side end face of the slide valve is located closer to the suction side than the bulkhead Has been. For this reason, there is a problem that fluid leaks from the compression chamber to the suction pressure side.
- the length of the slide valve in the circumferential direction of the screw rotor should be long enough to cover the screw groove at the start of partial load discharge so that the discharge area is sufficiently large.
- the connecting portion is arranged on the slide valve whose length in the circumferential direction of the screw rotor is longer than the position of Patent Document 4 so that the connecting portion does not block the discharge flow path.
- the portion may be provided completely away from the discharge port.
- Patent Documents 1 to 4 disclose various techniques for suppressing an increase in discharge loss in a wide operating range from a high compression ratio to a low compression ratio, but there is room for further improvement. It was.
- the present invention has been made to solve at least one of the problems as described above, and an object of the present invention is to obtain a screw compressor and a refrigeration cycle apparatus capable of suppressing an increase in discharge loss over a wide operating range.
- the screw compressor according to the present invention includes a screw rotor having a plurality of screw grooves formed on the outer peripheral surface, one end being a fluid suction side and the other end being a discharge side, and a plurality of teeth meshed with the screw grooves.
- a sliding valve that is slidably movable in the axial direction, and that slides in the rotational axis direction to change the discharge start timing; and a gate rotor opening that is provided in the casing and opens in the housing portion.
- a plurality of teeth are inserted into the receiving portion through the gate rotor opening and meshed with the screw groove.
- a screw compressor that sucks and compresses fluid into a compression chamber that is a space surrounded by the inner wall surface of the housing portion, the screw groove, and the gate rotor by rotating, and discharges the compressed fluid from the discharge port.
- the discharge port is a variable port that can change the opening area and discharge start timing by moving the slide valve, and a fixed port that is provided between the variable port and the gate rotor so that the opening area does not change even if the slide valve moves
- the shape of the suction port end surface of the discharge port when the slide valve is disposed on the most suction side is at the boundary between the inclined surface of the variable port and the fixed port and the variable port and extends in the direction of the rotation axis
- the slide surface and the inclined surface on the fixed port side are formed to have a Z-shape that is connected to each other at an angle. It is formed on the discharge side of the slope.
- FIG. 2 is a cross-sectional view taken along the line AA in FIG. It is a perspective view which shows the discharge port 15 vicinity (accommodating part) of the screw compressor 100 which concerns on Embodiment 1 of this invention. It is explanatory drawing of the discharge port 15 vicinity of the screw compressor 100 which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the compression principle of the screw compressor 100 which concerns on Embodiment 1 of this invention.
- FIG. 6 is a view showing another example of the suction side wall surface of the fixed port 17.
- FIG. 6 is a pressure-specific enthalpy diagram when the high-low differential pressure is small in partial load operation of the refrigeration cycle apparatus 300 according to Embodiment 2 of the present invention. It is explanatory drawing for demonstrating the relationship between the screw rotation angle in the screw compressor 200 which concerns on Embodiment 2 of this invention, and the economizer port 12p.
- FIG. 7 is an explanatory view of a modified example of the diameter of the economizer port 12p, in which (a) is a development view of the inner wall surface of the accommodating portion 1A and the outer peripheral surface of the screw rotor 4, and (b) shows a dd section of (a).
- FIG. 1 is a schematic sectional view (plan sectional view) of a screw compressor 100 according to Embodiment 1 of the present invention.
- FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 and 2 and the drawings shown below, the same reference numerals denote the same or corresponding parts, and this is common throughout the entire specification. Furthermore, the forms of the constituent elements appearing in the entire specification are merely examples and are not limited to these descriptions.
- the screw compressor 100 includes a casing 1, a screw rotor 4, a gate rotor 7, an electric motor 8 that rotationally drives the screw rotor 4, a slide valve 12, and the like.
- the casing 1 accommodates the screw rotor 4, the gate rotor 7, the electric motor 8, the slide valve 12, and the like.
- the casing 1 is formed with a discharge port 15 (see FIG. 3 described later) that opens to the accommodating portion 1A. Details of the discharge port 15 will be described later.
- a housing portion 1A which is a substantially cylindrical space, is formed inside the casing 1, and a substantially cylindrical screw rotor 4 is housed inside the housing portion 1A.
- the screw rotor 4 has one end on the fluid suction side and the other end on the discharge side.
- a plurality of screw grooves 10 are spirally formed on the outer peripheral surface of the screw rotor 4.
- a rotating shaft 9 serving as a driving shaft is provided at the center of the screw rotor 4 so as to rotate integrally.
- the rotating shaft 9 is rotatably supported by a high pressure side bearing 2 and a low pressure side bearing 3 provided in the casing 1.
- An electric motor 8 whose frequency is controlled by, for example, an inverter (not shown) is connected to the end of the rotary shaft 9 on the low-pressure side bearing 3 side.
- a pair of gate rotor support chambers 6 are formed in the casing 1 so as to face each other with the accommodating portion 1A (that is, the screw rotor 4) as a center.
- Each gate rotor support chamber 6 accommodates a substantially disc-shaped gate rotor 7.
- the gate rotor 7 is provided in the gate rotor support 5 accommodated in the gate rotor support chamber 6.
- the gate rotor support 5 is disposed such that a central axis (rotating shaft) 5b thereof is substantially perpendicular to the rotating shaft 9 of the screw rotor 4, and is freely rotatable by a bearing 5a that is disposed to face the central shaft 5b in a spaced manner. It is supported.
- the gate rotor 7 forms the compression chamber 11 together with the accommodating portion 1A and the screw rotor 4, and a plurality of gate rotor teeth 7a to be engaged with the screw grooves 10 are formed on the outer peripheral portion thereof. More specifically, the casing 1 is formed with a gate rotor opening 1a extending in the direction of the rotating shaft 9 (see FIG. 1). The gate rotor opening 1a is formed so as to extend along the inclination of the screw groove 10 on the back surface, and is connected to the suction wall 1c of the housing portion 1A forming the compression chamber on the back surface.
- the outer periphery of the gate rotor 7 is inserted into a gate rotor opening 1 a provided in the casing 1. That is, the gate rotor teeth 7 a of the gate rotor 7 are inserted into the accommodating portion 1 ⁇ / b> A through the gate rotor opening 1 a and meshed with the screw groove 10. Thereby, a space surrounded by the gate rotor 7, the inner wall surface of the accommodating portion 1A and the screw rotor 4 (in other words, the gate rotor teeth 7a of the gate rotor 7 and the screw groove 10 partitioned by the accommodating portion 1A) is formed. This space becomes the compression chamber 11.
- two slide grooves 14 extending in the direction of the rotary shaft 9 of the screw rotor 4 are formed on the inner wall surface of the casing 1, and the slide valve 12 is slidably accommodated in the slide groove 14.
- the two slide grooves 14 are formed in a substantially cylindrical shape, and a part of the inner peripheral surface communicates with the accommodating portion 1A. These two slide grooves 14 are arranged to be rotated by 180 ° about the rotation shaft 9 of the screw rotor 4.
- the slide valve 12 provided in the slide groove 14 is formed in a substantially cylindrical shape like the slide groove 14.
- the slide valve 12 has a shape in which a part of a cylinder is cut out so that the facing surface 1e facing the housing portion 1A has a shape along the outer peripheral wall of the housing portion 1A.
- the slide valve 12 is connected to a linear motion actuator (not shown) via a connecting portion 12 c, and the slide valve 12 is driven in the slide groove 14 by driving the linear motion actuator. Move in the direction.
- FIG. 3 is a perspective view showing the vicinity (container) of discharge port 15 of screw compressor 100 according to Embodiment 1 of the present invention.
- 3 is a perspective view as seen from the white arrow B side in FIG. 3A shows a state where the slide valve 12 is moved to the discharge side, and
- FIG. 3B shows a state where the slide valve 12 is moved to the suction side.
- a guide portion and the like connected to the connecting portion 12 c are not shown.
- FIG. 4 is an explanatory view of the vicinity of the discharge port 15 of the screw compressor 100 of FIG. 3, and shows a state when the slide valve 12 is located closest to the suction side.
- the “most suction side” here means the “most suction side” in the movement range of the slide valve 12 in adjusting the discharge timing, and the entire slide range of the slide valve 12 is defined. Does not necessarily match the “most inhalation side”. In other words, when the movement range of the slide valve 12 and the slide range of the slide valve 12 in adjusting the discharge timing are the same, they coincide, but otherwise, the “most suction side” here is the slide valve 12. In some cases, the position is closer to the discharge side than the “most suction side” of the slide range. In the following description, “most discharge side” has the same meaning.
- the slide valve 12 is movably accommodated in the slide groove 14 (see FIG. 4) in parallel with the rotation shaft 9 (see FIG. 1), and changes the position of the discharge-side end surface 12 d of the slide valve 12.
- the discharge start timing is adjusted. That is, the slide valve 12 slides to the suction side to accelerate the discharge start timing when the compression ratio is relatively small during partial load operation, and also when the compression ratio is relatively large during full load operation and partial load operation. In this case, the discharge start timing is delayed by sliding to the discharge side.
- the discharge port 15 is formed by the inner wall surface of the opening 1B formed in the casing 1 (more specifically, the opening that opens in the housing 1A in the casing 1) and the discharge-side end surface 12d of the slide valve 12. Yes.
- the discharge port 15 is defined as shown in FIG. That is, the discharge port 15 has a variable port 16 (thick hatched portion in the figure) and a fixed port 17 (thin hatched portion in the figure).
- the variable port 16 is configured by a region of the discharge port 15 that opens to the same screw rotor central angle range ⁇ 1 as the slide valve 12. In other words, the variable port 16 is configured by a region portion of the discharge port 15 that overlaps with a region in which the facing surface 1e of the slide valve 12 is extended in the slide direction.
- the variable port 16 varies the discharge start timing according to the position of the discharge side end of the slide valve 12.
- the variable port 16 has a variable opening area according to the position of the discharge side end of the slide valve 12.
- the fixed port 17 is a region other than the variable port 16 in the discharge port 15 and is a portion formed between the variable port 16 and the gate rotor 7 (see FIG. 3).
- the rotation side slide surface of the variable port 16 is defined as 16l
- the counter rotation side slide surface is defined as 16r.
- the suction side end surface of the fixed port 17 has a step, and hereinafter, it is defined as an inclined surface 17a and a vertical surface 17b from the variable port 16 side with the step portion as a boundary.
- a portion including the inclined surface 17a is distinguished as a divided fixed port 17ax
- a portion including the vertical surface 17b is distinguished as a divided fixed port 17bx.
- the shape of the suction side end face of the discharge port 15 is substantially Z-shaped. That is, the suction-side end surface of the discharge port 15 includes the vertical surface 17b and is not completely Z-shaped, but the discharge-side end surface 12d of the slide valve 12 (hereinafter sometimes referred to as an inclined surface 12d) and the slide surface 16l
- the inclined surface 17a is formed to have a Z shape that is connected at an angle to each other, and has a substantially Z shape as a whole.
- This Z shape is a Z shape in which the inclined surface 17a on the fixed port 17 side is formed on the higher pressure side than the inclined surface 12d on the variable port 16 side in the suction side end surface of the discharge port 15.
- the divided fixed port 17bx of the fixed ports 17 is provided in the casing 1 so that fluid can be discharged to the end at the end of the discharge stroke.
- the suction side end face of the divided fixed port 17bx is a vertical face 17b, but the shape and position are not limited thereto.
- the mounting position of the slide valve 12 will be described.
- the angle from the end surface on the slide valve 12 side of the gate rotor opening 1a (hereinafter referred to as the gate rotor opening surface) 1aa to the center of the slide valve 12 is defined as ⁇ 3,
- the mounting position of the slide valve 12 is shown by an angle.
- the lower limit of ⁇ 3 is set to a value larger than the conventional 30 ° which can increase the discharge area.
- the upper limit of ⁇ 3 is an angle at which the slide valve 12 does not interfere with the gate rotor support component on the opposite surface. This changes depending on the size of the slide valve 12.
- the upper limit of ⁇ 3 is 100 °.
- the formation range of the divided fixed port 17bx is ⁇ 2 in the screw rotor central angle range, for example, about 10 °.
- FIG. 5 is an explanatory diagram showing the compression principle of the screw compressor 100 according to Embodiment 1 of the present invention.
- the screw rotor 4 is rotated by a motor 8 (see FIG. 1) via a rotating shaft 9 (see FIG. 1), so that the gate rotor teeth 7 a of the gate rotor 7 pass through the screw groove 10.
- a motor 8 see FIG. 1
- a rotating shaft 9 see FIG. 1
- the suction stroke, the compression stroke, and the discharge stroke are set as one cycle, and this cycle is repeated.
- each stroke will be described focusing on the compression chamber 11 shown in gray in FIG.
- FIG. 5A shows the state of the compression chamber 11 during the suction stroke.
- the lower gate rotor 7 shown in FIG. 5 rotates in the direction of the white arrow as the screw rotor 4 rotates.
- the upper gate rotor 7 shown in FIG. 5 rotates in the opposite direction to the lower gate rotor 7 as indicated by a hollow arrow.
- the compression chamber 11 has the largest volume, communicates with the low pressure space of the casing 1 (see FIG. 1), and is filled with low pressure refrigerant gas.
- the compression chamber 11 communicates with the discharge port 15 as shown in FIG. As a result, the high-pressure refrigerant gas compressed in the compression chamber 11 is discharged from the discharge port 15 to the outside. Then, the same compression is performed again on the back surface of the screw rotor 4.
- the open screw groove 10 that is not covered by the casing 1 (that is, the inner wall surface of the housing portion 1A) communicates with the gate rotor 7 and the gate rotor support chamber 6 on the opposite side, and becomes a suction pressure atmosphere. Yes.
- FIGS. 6 to 9 are explanatory diagrams for explaining the relationship between the screw rotation angle and the discharge area in the screw compressor 100 according to Embodiment 1 of the present invention.
- 6 and 8 show development views of the inner wall surface of the accommodating portion 1A and the outer peripheral surface of the screw rotor 4.
- FIG. FIG. 6 shows a state when the slide valve 12 is arranged on the discharge side (an operation state with a relatively large compression ratio)
- FIG. 8 shows a state when the slide valve 12 is arranged on the suction side (partial load). Operation state with a relatively small compression ratio).
- the substantial discharge area of the screw compressor 100 is the area of the area where the discharge port 15 and the screw groove 10 face each other, and is indicated by the grid line portions C1 to C3 and the diagonal lines directed diagonally downward to the right in FIGS.
- the hatched portions D1 to D3 and the horizontal lines E1 to E2 indicate substantial discharge areas (opposite regions between the discharge port 15 and the screw groove 10), respectively.
- FIGS. 7 and 9 are characteristic diagrams showing the discharge areas corresponding to FIGS. 6 and 8, respectively. 7 and 9, the horizontal axis represents the screw rotation angle, and the vertical axis represents the discharge area.
- FIGS. 7 and 9 (a) show changes in the variable port area, and (b) show changes in the fixed port area, each represented by an upwardly convex parabola, and the sum of (a) and (b) is This is the discharge port area.
- FIG. 6A shows the discharge area C1 of the screw rotation angle ⁇ A (1) and the discharge area D1 of the screw rotation angle ⁇ A (4).
- FIG. 6B shows the discharge area C2 of the screw rotation angle ⁇ A (2) and the discharge area D2 of the screw rotation angle ⁇ A (5).
- FIG. 6C shows the discharge area C3 of the screw rotation angle ⁇ A (3) and the discharge area D3 of the screw rotation angle ⁇ A (6). That is, in FIG. 6, the screw groove 10 advances in the order of the rotation angle ⁇ A (1) ⁇ ⁇ A (2) ⁇ ⁇ A (3) ⁇ ⁇ A (4) ⁇ ⁇ A (5) ⁇ ⁇ A (6). (Area) changes from C1-> C2-> C3-> D1-> D2-> D3.
- the inside of the compression chamber 11 reaches the discharge pressure, while the fixed port 17 of the discharge port 15 starts to open (C1).
- the suction-side end surface (inclined surface 17a) of the fixed port 17 is formed along the inclination of the opposing screw groove 10 so as to ensure the maximum discharge area. That is, if the suction side end face of the fixed port 17 is formed along the inclination of the opposing screw groove 10, when the screw groove 10 moves downward in FIG. The discharge area expands from the entire surface 17a. For this reason, the maximum discharge area can be secured.
- the inclined surface 17a of the fixed port 17 does not necessarily have to be formed along the inclination of the screw groove 10 facing each other. In short, the opening area of the discharge port 15 at the start of discharge is ensured as large as possible. It is sufficient if it is formed in consideration of the above.
- the slide valve 12 is moved to the discharge side, and the compressed fluid is discharged mainly from the fixed port 17 side. .
- FIG. 8A shows a discharge area C1 of the screw rotation angle ⁇ B (1), a discharge area D1 of the screw rotation angle ⁇ B (4), and a discharge area E1 of the screw rotation angle ⁇ B (7).
- FIG. 8B shows the discharge area C2 of the screw rotation angle ⁇ B (2), the discharge area D2 of the screw rotation angle ⁇ B (5), and the discharge area E2 of the screw rotation angle ⁇ B (8).
- FIG. 8C shows the discharge area C3 of the screw rotation angle ⁇ B (3) and the discharge area D3 of the screw rotation angle ⁇ B (6). That is, in FIG.
- the screw groove 10 has a rotation angle ⁇ B (1) ⁇ ⁇ B (2) ⁇ ⁇ B (3) ⁇ ⁇ B (4) ⁇ ⁇ B (5) ⁇ ⁇ B (6) ⁇ ⁇ B (7) ⁇ ⁇ B (8 ) In this order, and the discharge area (opposite region) changes from C1, C2, C3, D1, D2, D3, E1, and E2.
- the inside of the compression chamber 11 reaches the discharge pressure, while the variable port 16 of the discharge port 15 starts to open (C1).
- the discharge-side end face 12d of the slide valve 12 is formed along the slope of the opposing screw groove 10 so as to ensure the maximum discharge area. That is, when the discharge-side end face 12d of the slide valve 12 is formed along the inclination of the opposing screw groove 10, when the screw groove 10 moves downward in FIG. The discharge area expands from the entire discharge side end face 12d of the slide valve 12. For this reason, the maximum discharge area can be secured.
- the discharge-side end face 12d of the slide valve 12 does not necessarily have to be formed along the slope of the opposing screw groove 10, and the point is that the opening area of the discharge port 15 at the start of discharge is as large as possible. It is sufficient if it is formed in consideration of the above.
- variable port 16 contracts and becomes not ⁇ B * (FIG. 9). Since the discharge area of the fixed port 17 is increased while the variable port 16 is reduced, the discharge area of the discharge port 15 is secured relatively large by a gentle change in ⁇ B (3) to ⁇ B * (FIG. 8).
- the discharge area of the discharge port 15 follows the same area change as D1-> D2-> D3 in FIG. 7, as shown by D3-> E1-> E2 in FIG.
- FIG. 10 is an explanatory view of the vicinity of a conventional discharge port 150 to be compared.
- the discharge port 150 includes a variable port 160 and a substantially rectangular fixed port 170.
- the position of the slide valve 120 is different from that of the slide valve 12 of the first embodiment.
- the formation range of the fixed port 170 is ⁇ 2 in the screw rotor central angle range, and is about 10 °, for example, equivalent to ⁇ 2 shown in FIG.
- FIG. 11 is an explanatory diagram for explaining the relationship between the screw rotation angle and the discharge area when the compression ratio is large and the conventional slide valve 120 of FIG. 10 is arranged on the discharge side.
- FIG. 12 is a diagram showing a comparison result of the discharge area between the conventional example and the first embodiment in a state where the slide valve is arranged on the discharge side.
- the compressed fluid is discharged from the variable port 160 from the first half to the second half of the discharge process. Therefore, the connecting portion 120c of the slide valve 120 is always positioned on the discharge port 150, and the discharge flow path is closed.
- the connecting portion 12c is configured as follows so that the discharge fluid discharged from the discharge port 15 is not blocked and the discharge area at the start of discharge can be secured to the maximum. That is, the slide valve 12 is disposed on the counter-rotation direction side (upward in FIG. 15 described later) with respect to the conventional slide valve 120, and the compressed fluid is mainly used in the state where the slide valve 12 is disposed on the discharge side. The liquid is discharged from the fixed port 17 side.
- the variable port 16 side of the suction-side end surface of the fixed port 17 is not a vertical surface but an inclined surface 17a. The point that the inclined surface 17a is effective in securing the maximum discharge area at the start of discharge is as described above.
- the discharge area of the first embodiment is obtained by changing the discharge area from the variable port 16 in addition to the discharge area of the conventional fixed port 17 without changing the discharge start timing. Can be increased. As a result, the discharge area in the first half of the discharge process in which the discharge area is small and the discharge flow rate is high can be increased, so that the discharge loss can be further reduced.
- FIG. 13 is an explanatory diagram for explaining the relationship between the screw rotation angle and the discharge area when the conventional slide valve 120 of FIG. 10 is disposed on the suction side in the low compression ratio operation.
- FIG. 13A is an explanatory diagram for explaining a difference in variable port area in the low compression ratio operation due to a difference in slide valve arrangement between the conventional and the first embodiment.
- FIG. 14 is a diagram showing a comparison result of the discharge area between the conventional example and the first embodiment in a state where the slide valve is arranged on the suction side.
- FIG. 14A is a diagram illustrating a change in discharge area when the center of the slide valve 12 is provided at 90 ° from the gate rotor opening surface 1aa.
- FIG. 14B is a diagram showing a comparison result of the discharge area between the case where the center of the slide valve 12 is provided at 90 ° from the gate rotor opening surface 1aa and the conventional case.
- FIG. 13 The view of FIG. 13 is the same as the view of FIG. That is, in FIG. 13, the screw rotation angle is ⁇ B (1) ⁇ ⁇ B (2) ⁇ ⁇ B (3) ⁇ ⁇ B (4) ⁇ ⁇ B (5) ⁇ ⁇ B (6) ⁇ ⁇ B (7) ⁇ ⁇ B (8). It is shown that the discharge area changes in the order of C1, C2, C3, D1, D2, D3, E1, and E2.
- the conventional slide valve 120 is arranged on the suction side as compared with the first embodiment. A change in discharge area due to this difference will be described with reference to FIG. 13A.
- FIG. 13A shows the conventional slide valve 120 and the slide valve 12 of the first embodiment side by side, and compares the difference in discharge area depending on the position of the slide valve.
- FIG. 13 shows the states from the first half of the ejection process to the middle of the ejection process ( ⁇ B (1) ⁇ ⁇ B (2) ⁇ ⁇ B (4)) in order from (a) ⁇ (b) ⁇ (c).
- the hatched portion indicates the discharge area when the slide valve 12 is positioned
- the grid line portion indicates the discharge area when the slide valve 120 is positioned.
- the facing surface between the opening provided in the casing 1 and the screw groove 10 is a discharge area. Therefore, if the screw grooves 10 on the discharge side and the suction side are formed with the same inclination and without restriction from the suction side to the discharge side as shown by the one-dot chain line in FIG.
- the discharge area is the same regardless of the position of the slide valve 12.
- the shape of the screw groove 10 is different between the suction side and the discharge side, and as shown in FIG. 13A (a), the inclination angle ⁇ with respect to the screw axis direction is such that the suction side inclination angle ⁇ s> the discharge side inclination angle ⁇ d. Further, the screw groove 10 is eliminated on the discharge side end face 12d.
- the discharge area changes depending on the mounting position of the slide valve 12.
- the discharge side end face 12d of the slide valve 12 is located on the discharge side with respect to the discharge side end face 120d of the conventional slide valve 120, as shown in FIGS. 13A and 13B, the first half of the discharge process.
- the angle of inclination ⁇ of the screw groove 10 is small, and the variable port area can be made larger than before. That is, in FIG. 13A (a) and FIG. 13 (b), when the hatched portion and the grid line portion are compared, the area of the shaded portion is larger.
- the screw groove 10 on the slide valve 12 side disappears after the discharge process in FIG.
- variable port area on the slide valve 12 side becomes smaller than the variable port area on the conventional slide valve 120 side.
- the discharge area can be secured by the divided fixed port 17ax after the middle of the discharge process.
- the discharge area of the first embodiment is as shown in FIG. 14, and the total discharge area in the discharge process is the same as that of the conventional process, and the discharge area can be made uniform during the discharge process. .
- FIG. 14B is a diagram showing a comparison result of the discharge area between the case where the center of the slide valve 12 is provided at 90 ° from the gate rotor opening surface 1aa and the conventional case. Since the screw groove 10 is eliminated at the discharge side end face 12d, the variable port area of the slide valve 12 is small as shown in FIG. 14A (a), and the variable port area is eliminated at an early stage. As a result, when the center of the slide valve 12 is provided at 90 ° from the gate rotor opening surface 1aa, as shown in FIG. 14B, the discharge area in the first half of the discharge process is smaller and the total discharge area is smaller than in the prior art. . From the above, in the first embodiment, the center position of the slide valve 12 has an optimum point in the range of 30 ° ⁇ 3 ⁇ 90 °.
- the shape of the suction side end face of the discharge port 15 will be rearranged again.
- the divided fixed port of the suction side end face of the slide valve 12 is used. It is effective to set 17ax to the inclined surface 17a instead of the vertical surface.
- the discharge-side end surface 12d of the slide valve 12 is an inclined surface that follows the inclination of the screw groove 10. It is valid.
- the shape of the suction side end face of the discharge port 15 is studied together, it is effective that the shape of the suction side end face of the discharge port 15 is substantially Z-shaped in the state where the slide valve 12 is located at the most suction side. It will be.
- FIG. 15 is a cross-sectional view of the state where the slide valves 12 and 120 are arranged on the suction side in the low compression ratio operation.
- (A) is conventional,
- (b) shows the first embodiment.
- FIGS. 15A and 15B show the case where the screw rotation angle is the same ⁇ B1 (see FIGS. 8 and 13).
- reference numeral 18 denotes a partition that partitions the suction pressure and the discharge pressure, and the thick dashed line indicates the center of the seal surface.
- the slide valve 12 is arranged on the counter-rotation direction side (the upper side in FIG. 15) from the installation position of the gate rotor 7 with respect to the conventional slide valve 120. Therefore, in the first embodiment, the portion of the end 10a on the rotation direction side (lower side in FIG. 15) of the compression chamber that overlaps with the slide valve position in the screw rotor circumferential direction (up and down direction in FIG. 15) is conventional in the first embodiment. It is located on the discharge side (left side in FIG. 15). Therefore, the position of the discharge-side end face 12d of the slide valve 12 determined in accordance with the position of the end side 10a at the screw rotation angle ⁇ B1 at the discharge start point is on the discharge side (left side in FIG. 15) than before. Therefore, the discharge-side end surface 12d of the slide valve 12 is closer to the discharge side than the partition wall 18, so that a seal surface is formed and no leakage occurs.
- the suction side end face shape of the discharge port 15 when the slide valve 12 is disposed on the most suction side is the Z shape, the following effects can be obtained.
- the discharge-side end face 120d of the slide valve 120 when operating at a low compression ratio is located on the suction side from the partition wall 18, and leakage occurs, resulting in a reduction in efficiency.
- the slide valve 12 is arranged on the counter-rotation direction side (the upper side in FIG. 15) than the conventional slide valve 120. For this reason, the position of the slide valve 12 when the slide valve 12 is adjusted in accordance with the screw groove 10 at the discharge start point is located on the discharge side from the conventional one. Therefore, there is an effect that the operation range on the low compression ratio side in which the discharge side end face 12d of the slide valve 12 can be operated without exceeding the partition wall 18 dividing the suction pressure and the discharge pressure (no leakage occurs) can be expanded.
- this Embodiment 1 is an example, and the angle range which provides the slide valve 12 is not restricted to the range shown in FIG.
- a part of the suction side end surface of the fixed port 17 has the vertical surface 17b.
- the present invention is not limited to this.
- the inclined surface 17 c may be inclined as a whole by extending the inclination of the inclined surface 17 a without providing the vertical surface 17 b.
- the screw compressor of the type provided with the two gate rotors 7 has been described.
- the present invention is not limited to this, and even in a screw compressor of the type provided with one gate rotor 7, the discharge port 15 is formed in the shape shown in the first embodiment, so that a high loss can be obtained. It can be set as an efficient screw compressor.
- FIG. The second embodiment relates to a refrigeration cycle apparatus.
- FIG. 17 is a refrigerant circuit diagram of the refrigeration cycle apparatus 300 according to Embodiment 2 of the present invention.
- the refrigeration cycle apparatus 300 includes a screw compressor 200 driven by an inverter 101, a condenser 102, a high-pressure unit of an intercooler 103, an expansion valve 104 that is a decompression device, and an evaporator 105 in order by refrigerant piping. It has a connected refrigerant circuit.
- the refrigeration cycle apparatus 300 further branches from between the intermediate cooler 103 and the expansion valve 104 and is an economizer pipe connected to the screw compressor 100 via the intermediate cooler expansion valve 106 and the low pressure portion of the intermediate cooler 103. 107.
- the condenser 102 cools and condenses the discharge gas from the screw compressor 200.
- the expansion valve 104 squeezes and expands the liquid branched from the condenser 102.
- the evaporator 105 evaporates the refrigerant that has flowed out of the expansion valve 104.
- the intermediate cooler 103 exchanges heat between the high-pressure side refrigerant between the condenser 102 and the expansion valve 104 and the low-pressure side refrigerant obtained by decompressing part of the high-pressure side refrigerant with the expansion valve 106 for the intermediate cooler, to thereby exchange the high-pressure side refrigerant. Cool down.
- the refrigeration cycle apparatus 300 further includes a refrigeration cycle including control of the inverter 101, the expansion valve 104 and the intercooler expansion valve 106, control of the position of the slide valve 12 of the screw compressor 200, and driving and stopping of an economizer operation described later.
- a control device 301 is provided for controlling the entire device.
- FIG. 18 is an end view of the main part of the screw compressor 200 provided in the refrigeration cycle apparatus 300 according to Embodiment 2 of the present invention.
- FIG. 19 is a perspective view showing the vicinity (accommodating portion) of discharge port 15 of screw compressor 200 provided in refrigeration cycle apparatus 300 according to Embodiment 2 of the present invention.
- FIG. 20 is an explanatory view of the vicinity of the discharge port 15 of the screw compressor 200 provided in the refrigeration cycle apparatus 300 according to Embodiment 2 of the present invention.
- the screw compressor 200 is substantially the same as the screw compressor 100 of the first embodiment, and the following description will focus on the points that the screw compressor 200 is different from the screw compressor 100.
- the screw compressor 200 is provided with an economizer channel 50 in the casing 1 for guiding the refrigerant gas from the intercooler 103 to the compression chamber 11 (screw groove 10 in the compression process).
- the economizer channel 50 is provided in the casing 1 so as to communicate the outside of the casing 1 and the slide groove 14.
- the economizer pipe 107 is connected to the economizer flow path 50 and connects the intermediate cooler 103 and the economizer flow path 50.
- the screw compressor 200 further has an economizer port 12 p formed in the cylindrical portion of the slide valve 12.
- the economizer port 12p has an inner peripheral surface that is a slidable contact surface with the screw rotor 4 in the slide valve 12 from an outer peripheral surface that is a slidable contact surface with the slide groove 14 in the slide valve 12, as shown in the right diagram of FIG. It is formed so as to penetrate through.
- the inside of the open screw groove 10 (see FIG. 19) not covered with the casing 1 (that is, the inner wall surface of the housing portion 1A)
- the gate rotor support chamber 6 (the gate rotor 7 and the gate rotor support chamber 6 which are not shown in FIG. 19) communicates with the suction pressure atmosphere.
- a space (including the gate rotor support chamber 6) in the casing 1 that is not covered by the inner wall surface of the accommodating portion 1A and is in the suction pressure atmosphere is defined as a suction pressure chamber 1C.
- FIG. 21 is an explanatory diagram in the vicinity of an economizer port according to Embodiment 2 of the present invention.
- An economizer flow path 50 communicating the economizer pipe 107 and the slide groove 14 is provided in the casing 1 as shown in FIG.
- the economizer flow path 50 has a pipe line 50a connected to the economizer pipe 107 and a long groove 50b connected to the slide groove 14 side.
- the long groove 50b is configured to extend along the slide surface of the slide valve 12, and the length l of the long groove 50b is set to a length corresponding to the slide valve control position in the operation range in which the economizer operation is performed.
- the expansion valve 106 for the intermediate cooler is opened to allow the economizer pipe 107 and the screw compressor 100 to communicate with each other, and the economizer gas that has passed through the low pressure portion of the intermediate cooler 103 is supplied to the screw compressor 100. It is the operation
- the groove width (length in the circumferential direction of the screw rotor) of the long groove 50b is larger than the diameter d of the economizer port 12p as shown in the right figure of FIG.
- the economizer port diameter d is set to the maximum diameter (not more than the minimum tooth thickness) that does not allow communication between adjacent compression chambers of the screw rotor 4.
- FIG. 22 is an explanatory diagram of the refrigeration cycle during the economizer operation of the refrigeration cycle apparatus 300 according to Embodiment 2 of the present invention.
- FIG. 23 is a pressure-specific enthalpy diagram during full load operation of the refrigeration cycle apparatus 300 according to Embodiment 2 of the present invention.
- the arrows in FIG. 22 indicate the flow of the refrigerant, the solid line is the refrigerant liquid, and the broken line is the refrigerant gas.
- the refrigerant state at each numerical position in parentheses in FIG. 23 corresponds to the refrigerant state at each corresponding numerical pipe position in FIG.
- the refrigerant gas (1) having the pressure Ps exiting the evaporator 105 is sucked into the screw compressor 100, compressed to the pressure Pd, and then discharged.
- the discharged refrigerant gas (5) is supercooled to the state (6) by the condenser 102.
- the high-pressure supercooled liquid (6) enters the high-pressure part of the intercooler 103 and is further cooled to the state (8).
- a part of the high-pressure liquid (8) discharged from the intermediate cooler 103 is branched and expanded by the intermediate cooler expansion valve 106 to the intermediate pressure Pm, and again in the state (7), the low-pressure portion of the intermediate cooler 103 is expanded. Flow into.
- the refrigerant liquid (low-pressure side refrigerant) (7) that has flowed again into the low-pressure part of the intercooler 103 evaporates into a refrigerant gas (7a) by heat exchange with the high-pressure side refrigerant.
- the refrigerant gas (7a) is injected into the screw groove 10 during compression from the economizer port 12p provided in the slide valve 12 via the economizer pipe 107 and the economizer flow path 50, and mixed with the compressed gas. ((2)-(3)).
- FIG. 24 is a pressure-specific enthalpy diagram when the differential pressure difference is small in the partial load operation of the refrigeration cycle apparatus 300 according to Embodiment 2 of the present invention.
- the differential pressure between the intermediate pressure (intermediate cooler outlet) and the compression chamber is small as shown in FIG. 24, and the intermediate pressure ⁇ compression chamber becomes transient during the economizer operation. Operation becomes unstable.
- the effect of expanding the refrigerating capacity is small, and the power increase due to the economizer gas flowing in the middle of compression becomes larger and the coefficient of performance decreases. Therefore, under the condition where the high / low differential pressure is small, the intermediate cooler expansion valve 106 in FIG. 22 is closed so that the economizer operation is not performed.
- FIGS. 25 and 26 are explanatory diagrams for explaining the relationship between the screw rotation angle and the economizer port in the screw compressor 200 according to Embodiment 2 of the present invention.
- FIG. 25 shows a state when the slide valve 12 is arranged on the discharge side (an operation state where the compression ratio is large such as full load operation).
- FIG. 26 shows a state when the slide valve 12 is disposed on the suction side (an operation state in which the compression ratio is relatively small even in partial load operation).
- FIGS. 25A to 25C and FIGS. 26A to 26C are development views of the outer peripheral surface of the screw rotor 4.
- FIGS. 25 (d) and 26 (d) are CC cross-sectional views of FIGS. 25 (a) and 26 (a).
- FIG. 25 shows that the screw groove 10 has a rotation angle ⁇ A (1) ⁇ ⁇ A (2) ⁇ ⁇ A (3) ⁇ ⁇ A (4) ⁇ ⁇ A (5) ⁇ ⁇ A (6) ⁇ ⁇ A (7) ⁇ ⁇ A (8 ) ⁇ ⁇ A (9) in this order, and the volume of the screw groove 10 is reduced.
- the screw groove 10 has a rotation angle ⁇ B (1) ⁇ ⁇ B (2) ⁇ ⁇ B (3) ⁇ ⁇ B (4) ⁇ ⁇ B (5) ⁇ ⁇ B (6) ⁇ ⁇ B (7) ⁇ ⁇ B (8 ) ⁇ ⁇ B (9) ⁇ ⁇ B (10) ⁇ ⁇ B (11), and the volume of the screw groove 10 is reduced.
- the screw grooves B1 and B2 hatched with diagonal lines are the screw grooves 10 in the suction process. That is, the screw grooves B1 and B2 are in positions that are not completely closed by the gate rotor 7 and the inner wall surface of the accommodating portion 1A. Also, the screw grooves A1, A2, A3, and B3 filled in FIGS. 25 and 26 are screw grooves 10 in the compression process. Further, unfilled screw grooves A4 to A9 and B4 to B11 are screw grooves 10 in the discharging process. The substantial discharge area in the discharge process is the area of the area where the discharge port 15 and the screw groove 10 face each other, and is indicated by the grid lines in FIGS.
- the economizer port 12p starts to communicate with the low-pressure screw groove A1 immediately after completing the suction.
- the economizer port 12p travels on the screw grooves A2 ⁇ A3 during the compression stroke. While the economizer port 12p travels on the screw grooves A2 ⁇ A3, the economizer gas is injected from the economizer port 12p into the screw groove 10 due to the differential pressure between the intermediate pressure Pm and the screw groove 10.
- the economizer port 12p is opened in the screw groove 10 that is at a high pressure, the intermediate pressure is increased, and the effect of expanding the capacity by the economizer operation (the degree of supercooling in (8) of FIG. 23) is reduced. Therefore, here, the economizer gas is injected into the screw groove 10 as low as possible.
- the economizer port 12p communicates with the screw groove 10 at the timing when the suction is almost completed. That is, as shown in FIG. 25A, the economizer port 12p starts to communicate with the screw groove A1 at the start of compression, passes through the screw grooves A2 and A3 during the compression process, and is completely screwed with the screw groove A4. This is repeated.
- the economizer operation is performed by connecting the economizer flow path 50 provided in the casing 1 and the economizer port 12p under the condition that the differential pressure is relatively large even in the partial load operation and the economizer effect is obtained. .
- the slide valve 12 is moved from the full load operation to the suction side or is positioned at the same slide position as the full load operation.
- the economizer port 12p is always in communication with the suction pressure chamber 1C. Therefore, when the differential pressure is small in the partial load operation, the operation is performed in a state where the economizer port 12p is not involved in the screw groove 10 from the suction process to the discharge process.
- the economizer port becomes a volume portion (dead volume) where it is compressed wastefully from the suction pressure to the discharge pressure. Therefore, a re-expansion loss occurs when the economizer port passes over the screw groove while the economizer operation is stopped.
- the economizer port 12p is not involved at all in the operation of stopping the economizer operation, it is possible to prevent the performance degradation due to the re-expansion loss. Further, the partial load operation has a small capacity, and the influence of leakage between adjacent compression chambers becomes remarkable. However, in the configuration of the second embodiment, the economizer port 12p is completely involved when the economizer operation is stopped. By eliminating, leakage between the screw grooves 10 due to passing through the economizer port 12p can be eliminated.
- the economizer flow path 50 and the economizer port 12p are prevented from communicating with each other.
- the economizer flow path 50 and the economizer port 12p are prevented from communicating with each other.
- FIG. 26A when the slide valve is on the suction side, if the economizer pipe 107 is closed by the intermediate cooler expansion valve 106 or the like, the economizer gas leaks to the suction side, and the compression chamber of the suction gas 11 is not hindered. For this reason, the economizer flow path 50 and the economizer port 12p may be communicated with each other from the viewpoint of common parts and the like.
- FIG. 27 is an explanatory view of a modified example of the diameter of the economizer port 12p.
- (A) is a developed view of the inner wall surface of the accommodating portion 1A and the outer peripheral surface of the screw rotor 4, and (b) is a dd section of (a). Show.
- the economizer port 12p has a diameter that does not allow communication between adjacent compression chambers.
- the economizer port 12p may be larger than the land width (width of the groove between adjacent screw grooves) as shown in FIG. 27 (a). There is a similar effect.
- the second embodiment can obtain the same effects as those of the first embodiment and the following effects. That is, in the second embodiment, the position of the economizer port 12p provided on the slide valve 12 is the position where the economizer port 12p communicates with the economizer flow path 50 when the slide valve 12 is at the most discharge side. When the slide valve 12 is on the most suction side, the economizer port 12p is in a position where it communicates with the suction pressure chamber 1C. With this configuration, in a full load operation where the economizer effect is large and the pressure difference is large, the coefficient of performance can be improved by the economizer operation.
- 1 casing 1A housing, 1B opening, 1C suction pressure chamber, 1a gate rotor opening, 1aa gate rotor opening surface, 1c suction wall, 1e facing surface, 2 high pressure side bearing, 3 low pressure side bearing, 4 screw rotor 5, gate rotor support, 5a bearing, 5b central axis, 6 gate rotor support chamber, 7 gate rotor, 7a gate rotor teeth, 8 electric motor, 9 rotary shaft, 10 screw groove, 10a end, 11 compression chamber, 12 slide valve , 12c connecting part, 12d inclined surface on the variable port side (discharge end face), 12p economizer port, 14 slide groove, 15 discharge port, 16 variable port, 16l slide surface (rotation side slide surface), 16r anti-rotation side slide Surface, 17 fixed port, 17a fixed port side Slope, 17ax split fixed port, 17b vertical surface, 17bx split fixed port, 17c inclined surface, 18 bulkhead, 50 economizer flow path, 50a conduit, 50b long groove, 100 screw compressor, 101
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
Description
以下、本発明の実施の形態1に係るスクリュー圧縮機100について説明する。
図1は、本発明の実施の形態1に係るスクリュー圧縮機100の概略断面図(平面断面図)である。また、図2は、図1のA-A断面図である。なお、図1、図2及び以下に示す図において、同一の符号を付したものは同一又はこれに相当するものであり、これは明細書の全文において共通している。更に、明細書全文に表れている構成要素の形態は、あくまで例示であってこれらの記載に限定されるものではない。
次に、本実施の形態1に係るスクリュー圧縮機100の吐出ポート15近傍の詳細構成について説明する。
図3は、本発明の実施の形態1に係るスクリュー圧縮機100の吐出ポート15近傍(収容部)を示す斜視図である。なお、図3は、図2の白抜き矢印B側から見た斜視図である。また、図3(a)はスライドバルブ12が吐出側に移動している状態を示し、図3(b)はスライドバルブ12が吸入側に移動している状態を示している。また、図3では、吐出ポート15近傍をわかりやすく示すため、連結部12cに連結されるガイド部等の図示は省略している。
ここで、可変ポート16の回転側スライド面を16l、反回転側スライド面を16rと定義する。また、固定ポート17の吸入側端面は段差を有しており、以下では、段差部分を境として可変ポート16側から傾斜面17a、垂直面17bと定義する。また、以下では、固定ポート17を段差部分で周方向に2つに分割した部分のうち、傾斜面17aを含む部分を分割固定ポート17ax、垂直面17bを含む部分を分割固定ポート17bxとして区別する場合がある。
続いて上記のように構成されたスクリュー圧縮機100の動作について説明する。
図5は、本発明の実施の形態1に係るスクリュー圧縮機100の圧縮原理を示す説明図である。
以下、図6、図7を参照して、高圧縮比運転の場合、つまり全負荷運転の場合及び部分負荷運転で比較的圧縮比が大きい場合の吐出面積の変化を説明する。高圧縮比運転では、スライドバルブ12を吐出側へ移動した状態で運転を行う。
以下、図8及び図9を参照して、低圧縮比運転の場合、つまり部分負荷運転で比較的圧縮比の小さい場合の吐出面積の変化を説明する。
吐出ポート150は、可変ポート160と、略矩形状の固定ポート170とから構成されている。また、スライドバルブ120は、本実施の形態1のスライドバルブ12と位置が異なり、この例ではスライドバルブ120の角度幅は、φ1=40°で、スライドバルブ120の中心をゲートロータ開口面1aaからφ3=30°の位置に設けている。また、固定ポート170の形成範囲は、スクリューロータ中心角範囲でφ2であり、図4に示したφ2と同等の例えば10゜程度である。
図11は、圧縮比が大きく、図10の従来のスライドバルブ120が吐出側に配置された状態でのスクリュー回転角と吐出面積との関係を説明するための説明図である。図12は、スライドバルブが吐出側に配置された状態での従来と本実施の形態1との吐出面積の比較結果を示す図である。
図13は、低圧縮比運転で、図10の従来のスライドバルブ120が吸入側に配置された状態でのスクリュー回転角と吐出面積との関係を説明するための説明図である。図13Aは、従来と本実施の形態1とのスライドバルブ配置の違いによる、低圧縮比運転での可変ポート面積の違いを説明するための説明図である。図14は、スライドバルブが吸入側に配置された状態での従来と本実施の形態1との吐出面積の比較結果を示す図である。図14Aは、スライドバルブ12の中心をゲートロータ開口面1aaから90°に設けた場合の吐出面積の変化を示す図である。図14Bは、スライドバルブ12の中心をゲートロータ開口面1aaから90°に設けた場合と従来との吐出面積の比較結果を示す図である。
吐出側端面12dでスクリュー溝10がなくなるため、図14A(a)に示すようにスライドバルブ12の可変ポート面積が小さく、早い段階で可変ポート面積がなくなってしまう。その結果、スライドバルブ12の中心をゲートロータ開口面1aaから90°に設けた場合は、図14Bに示すように従来に比べて、吐出過程前半の吐出面積が小さく、更に総吐出面積も小さくなる。
以上から、本実施の形態1において、スライドバルブ12の中心位置は、30°<φ3<90°の範囲に最適点がある。
図15において、18は吸入圧と吐出圧とを区画する隔壁で、太一点鎖線はシール面の中心を示す。
本実施の形態2は、冷凍サイクル装置に関する。
冷凍サイクル装置300は、インバータ101で駆動されるスクリュー圧縮機200と、凝縮器102と、中間冷却器103の高圧部と、減圧装置である膨張弁104と、蒸発器105とを順に冷媒配管で接続した冷媒回路を備えている。冷凍サイクル装置300は更に、中間冷却器103と膨張弁104との間から分岐し、中間冷却器用膨張弁106及び中間冷却器103の低圧部を介してスクリュー圧縮機100に接続されたエコノマイザー配管107を有している。
次に、本実施の形態2に係るエコノマイザーポート12p近傍の詳細構成について説明する。
図21は、本発明の実施の形態2に係るエコノマイザーポート近傍の説明図である。
エコノマイザー配管107とスライド溝14とを連通するエコノマイザー流路50は、図21に示すようにケーシング1に設けられている。エコノマイザー流路50は、エコノマイザー配管107に接続する管路50aとスライド溝14側に接続する長溝50bとを有する。長溝50bはスライドバルブ12のスライド面に沿って延びるように構成され、長溝50bの長さlは、エコノマイザー運転を行う運転範囲のスライドバルブ制御位置に対応した長さとしている。
次に、本実施の形態2の動作について説明する。
まず、全負荷運転での冷媒回路の動作を説明する。
図24は、本発明の実施の形態2に係る冷凍サイクル装置300の部分負荷運転で高低差圧が小さいときの圧力-比エンタルピ線図である。
部分負荷運転で高低差圧が小さいときは、図24に示すように中間圧(中間冷却器出口)と圧縮室間の差圧が小さく、エコノマイザー運転時に過渡的に中間圧<圧縮室となって動作が不安定となる。その上、冷凍能力の拡大効果が小さく、エコノマイザーガスが圧縮途中に流入することによる動力増加の方が大きくなって成績係数が低下する。そのため、高低差圧が小さい条件では、図22の中間冷却器用膨張弁106を閉止し、エコノマイザー運転を行わないようにしている。
図25と図26は、本発明の実施の形態2に係るスクリュー圧縮機200におけるスクリュー回転角とエコノマイザーポートとの関係を説明するための説明図である。図25は、スライドバルブ12が吐出側に配置される時の状態(全負荷運転など圧縮比が大きい運転状態)を示している。図26は、スライドバルブ12が吸入側に配置される時の状態(部分負荷運転でも比較的圧縮比の小さい運転状態)を示している。また、図25(a)~(c)と図26(a)~(c)は、スクリューロータ4外周面の展開図を示している。図25(d)と図26(d)は、図25(a)と図26(a)のC-C断面図である。
図25を用いて、全負荷運転時のエコノマイザーポート12pとスクリュー溝10との位置関係を説明する。
全負荷運転ではエコノマイザー運転を行う。エコノマイザー運転では、スライドバルブ12は図25(d)に示すように吐出側に移動し、図25(a)~(c)に示すように可変ポート16を完全に閉塞する位置に配置される。また、ケーシング1に設けられたエコノマイザー流路50とエコノマイザーポート12pとは連通した状態になっている。
次に図26を用いて、部分負荷運転で高低差圧が小さいときのエコノマイザーポート12pとスクリュー溝10との位置関係を説明する。
部分負荷運転で高低差圧が小さいときはエコノマイザー運転を停止する。エコノマイザー運転を停止する場合、スライドバルブ12は、図26(d)に示すように吸入側に移動し、エコノマイザーポート12pを、図19(b)に示すように収容部1Aの内壁面のない部分(吸入圧室1C)に配置させる。この状態では、ケーシング1に設けられたエコノマイザー流路50とエコノマイザーポート12pとは連通しない状態になっている。また、エコノマイザー運転を停止中、エコノマイザーポート12pは、常に吸入圧室1Cに連通した状態になっている。したがって、部分負荷運転で高低差圧が小さいときは、吸入過程から吐出過程までエコノマイザーポート12pがスクリュー溝10に関与しない状態で運転が行われる。
本実施の形態2では、エコノマイザーポート12pは隣り合う圧縮室を連通しない径となっている。しかし、エコノマイザー運転でのみエコノマイザーポート12pを使用する場合、インジェクションされる冷媒の流れが、図27(b)の白抜き矢印に示すような流れであれば、隣り合う圧縮室間の漏れはない。よって、使用範囲によってはエコノマイザーポート12pを図27(a)に示すようにランド幅(隣り合うスクリュー溝の間の溝山の幅)より大きくしてもよく、この場合も実施の形態2と同様の効果がある。
Claims (7)
- 複数条のスクリュー溝が外周面に形成され、一端が流体の吸入側となり他端が吐出側となるスクリューロータと、
前記スクリュー溝に噛み合わされる複数の歯が外周部に形成されたゲートロータと、
前記スクリューロータが収容される収容部及び吐出ポートを有するケーシングと、
前記ケーシングの内壁面に形成され、前記スクリューロータの回転軸方向に延びるスライド溝と、
前記スライド溝内に前記回転軸方向にスライド移動自在に収容され、前記回転軸方向にスライドして吐出開始タイミングを変化させるスライドバルブと、
前記ケーシングに設けられ、前記収容部に開口するゲートロータ用開口部とを有し、
前記ゲートロータの前記複数の歯が前記ゲートロータ用開口部を介して前記収容部に挿入されて前記スクリュー溝と噛み合わされ、前記スクリューロータが回転することにより、前記収容部の内壁面、前記スクリュー溝及び前記ゲートロータで囲まれた空間である圧縮室に流体を吸入して圧縮し、圧縮した流体を吐出ポートから吐出するスクリュー圧縮機であって、
前記吐出ポートは、
前記スライドバルブの移動によって開口面積と吐出開始のタイミングとを変更できる可変ポートと、
前記可変ポートと前記ゲートロータとの間に設けられ、前記スライドバルブが移動しても開口面積が変化しない固定ポートとを有し、
前記スライドバルブが最も吸入側に配置されるときの前記吐出ポートの吸入側端面形状が、前記可変ポート側の傾斜面と、前記固定ポートと前記可変ポートとの境界にあって回転軸方向に延びるスライド面と、前記固定ポート側の傾斜面と、を互いに角度を持って接続したZ形状を有して形成され、前記固定ポート側の傾斜面が前記可変ポート側の傾斜面よりも吐出側に形成されていることを特徴とするスクリュー圧縮機。 - 前記吐出ポートの吸入側端面を形成する前記可変ポート側の傾斜面と前記固定ポート側の傾斜面との少なくとも一方が、対向するスクリュー溝の傾斜に沿って形成されていることを特徴とする請求項1記載のスクリュー圧縮機。
- 前記ケーシング内に設けられ、吸入圧力雰囲気となっている吸入圧室と、
前記ケーシング内に形成され、前記ケーシングの外部と前記スライド溝とを連通するエコノマイザー流路と、
前記スライドバルブに形成され、前記スライドバルブの位置に応じて、前記圧縮室に前記エコノマイザー流路を連通させるエコノマイザーポートとを備え、
前記スライドバルブは、吐出側から吸入側に移動するに連れ、吐出開始のタイミングを早めるものであり、
前記エコノマイザーポートは、前記スライドバルブが最も吸入側に移動した状態にあるときに前記吸入圧室に連通する位置に設けられていることを特徴とする請求項1又は請求項2記載のスクリュー圧縮機。 - 前記エコノマイザーポートは、前記スライドバルブが最も吐出側に移動した状態にあるときに前記圧縮室及び前記エコノマイザー流路に連通する位置に設けられていることを特徴とする請求項3記載のスクリュー圧縮機。
- 前記ゲートロータと前記スライドバルブとの組を一対備え、一対の前記スライドバルブのそれぞれの中心位置が、それぞれ同じ組の前記ゲートロータに対応する前記ゲートロータ用開口部における前記スライドバルブ側の端面から、スクリューロータ中心角度で、30°より大きく100°より小さい範囲に設けられていることを特徴とする請求項1~請求項4の何れか一項に記載のスクリュー圧縮機。
- 駆動軸を介して前記スクリューロータと接続され、前記スクリューロータを回転させる電動機を備え、
前記電動機は、インバータで駆動される電動機であることを特徴とする請求項1~請求項5の何れか一項に記載のスクリュー圧縮機。 - 請求項3~請求項6の何れか一項に記載のスクリュー圧縮機、凝縮器、中間冷却器の高圧部、減圧装置及び蒸発器を順に冷媒配管で接続した冷媒回路と、
前記中間冷却器と前記減圧装置との間から分岐し、中間冷却器用膨張弁及び前記中間冷却器の低圧部を介して前記スクリュー圧縮機の前記エコノマイザー流路に接続されたエコノマイザー配管とを備えたことを特徴とする冷凍サイクル装置。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2013/065000 WO2014192114A1 (ja) | 2013-05-30 | 2013-05-30 | スクリュー圧縮機及び冷凍サイクル装置 |
CN201380076927.7A CN105247216B (zh) | 2013-05-30 | 2013-05-30 | 螺杆式压缩机和冷冻循环装置 |
GB1519248.7A GB2528214C (en) | 2013-05-30 | 2013-05-30 | Screw compressor and refrigeration cycle apparatus |
JP2015519557A JP5951125B2 (ja) | 2013-05-30 | 2013-05-30 | スクリュー圧縮機及び冷凍サイクル装置 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2013/065000 WO2014192114A1 (ja) | 2013-05-30 | 2013-05-30 | スクリュー圧縮機及び冷凍サイクル装置 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014192114A1 true WO2014192114A1 (ja) | 2014-12-04 |
Family
ID=51988186
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/065000 WO2014192114A1 (ja) | 2013-05-30 | 2013-05-30 | スクリュー圧縮機及び冷凍サイクル装置 |
Country Status (4)
Country | Link |
---|---|
JP (1) | JP5951125B2 (ja) |
CN (1) | CN105247216B (ja) |
GB (1) | GB2528214C (ja) |
WO (1) | WO2014192114A1 (ja) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105508243B (zh) * | 2016-01-19 | 2019-07-23 | 珠海格力电器股份有限公司 | 一种单螺杆压缩机 |
WO2017149659A1 (ja) * | 2016-03-01 | 2017-09-08 | 三菱電機株式会社 | スクリュー圧縮機および冷凍サイクル装置 |
CN106762633A (zh) * | 2017-01-10 | 2017-05-31 | 麦克维尔空调制冷(苏州)有限公司 | 一种多螺杆式定频制冷压缩机 |
DE102017210876A1 (de) * | 2017-06-28 | 2019-01-03 | Robert Bosch Gmbh | Trägereinrichtung, Anordnung mit einer Trägereinrichtung und Verfahren zur Ausbildung einer Anordnung mit einer Trägereinrichtung |
GB2581526A (en) * | 2019-02-22 | 2020-08-26 | J & E Hall Ltd | Single screw compressor |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009019624A (ja) * | 2007-06-11 | 2009-01-29 | Daikin Ind Ltd | 圧縮機および冷凍装置 |
JP2009052566A (ja) * | 2008-11-25 | 2009-03-12 | Daikin Ind Ltd | 圧縮機および冷凍装置 |
JP4735757B2 (ja) * | 2009-12-22 | 2011-07-27 | ダイキン工業株式会社 | シングルスクリュー圧縮機 |
JP2012117477A (ja) * | 2010-12-02 | 2012-06-21 | Mitsubishi Electric Corp | スクリュー圧縮機 |
JP2012229640A (ja) * | 2011-04-26 | 2012-11-22 | Mitsubishi Electric Corp | スクリュー圧縮機 |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5509273A (en) * | 1995-02-24 | 1996-04-23 | American Standard Inc. | Gas actuated slide valve in a screw compressor |
JP2009024534A (ja) * | 2007-07-18 | 2009-02-05 | Daikin Ind Ltd | 冷凍装置 |
WO2011077724A1 (ja) * | 2009-12-22 | 2011-06-30 | ダイキン工業株式会社 | シングルスクリュー圧縮機 |
JP5389755B2 (ja) * | 2010-08-30 | 2014-01-15 | 日立アプライアンス株式会社 | スクリュー圧縮機 |
JP2013015085A (ja) * | 2011-07-05 | 2013-01-24 | Daikin Industries Ltd | スクリュー圧縮機 |
-
2013
- 2013-05-30 CN CN201380076927.7A patent/CN105247216B/zh active Active
- 2013-05-30 JP JP2015519557A patent/JP5951125B2/ja active Active
- 2013-05-30 GB GB1519248.7A patent/GB2528214C/en active Active
- 2013-05-30 WO PCT/JP2013/065000 patent/WO2014192114A1/ja active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009019624A (ja) * | 2007-06-11 | 2009-01-29 | Daikin Ind Ltd | 圧縮機および冷凍装置 |
JP2009052566A (ja) * | 2008-11-25 | 2009-03-12 | Daikin Ind Ltd | 圧縮機および冷凍装置 |
JP4735757B2 (ja) * | 2009-12-22 | 2011-07-27 | ダイキン工業株式会社 | シングルスクリュー圧縮機 |
JP2012117477A (ja) * | 2010-12-02 | 2012-06-21 | Mitsubishi Electric Corp | スクリュー圧縮機 |
JP2012229640A (ja) * | 2011-04-26 | 2012-11-22 | Mitsubishi Electric Corp | スクリュー圧縮機 |
Also Published As
Publication number | Publication date |
---|---|
GB201519248D0 (en) | 2015-12-16 |
GB2528214A (en) | 2016-01-13 |
JP5951125B2 (ja) | 2016-07-13 |
GB2528214C (en) | 2020-01-29 |
CN105247216A (zh) | 2016-01-13 |
JPWO2014192114A1 (ja) | 2017-02-23 |
GB2528214B (en) | 2020-01-08 |
CN105247216B (zh) | 2017-05-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6058133B2 (ja) | スクリュー圧縮機及び冷凍サイクル装置 | |
JP5951125B2 (ja) | スクリュー圧縮機及び冷凍サイクル装置 | |
JP6177449B2 (ja) | スクリュー圧縮機および冷凍サイクル装置 | |
JP4183021B1 (ja) | 圧縮機および冷凍装置 | |
JP6685379B2 (ja) | スクリュー圧縮機および冷凍サイクル装置 | |
JP6989811B2 (ja) | スクリュー圧縮機及び冷凍装置 | |
KR20120007337A (ko) | 압축기 | |
KR20050012633A (ko) | 용량 조절식 스크롤 압축기 | |
WO2017145251A1 (ja) | スクリュー圧縮機および冷凍サイクル装置 | |
JP2010156488A (ja) | 冷凍装置 | |
JP6234611B2 (ja) | スクリュー圧縮機および冷凍サイクル装置 | |
JP5836867B2 (ja) | スクリュー圧縮機 | |
JP5515289B2 (ja) | 冷凍装置 | |
JP5338314B2 (ja) | 圧縮機および冷凍装置 | |
JP6177450B2 (ja) | スクリュー圧縮機および冷凍サイクル装置 | |
JP2012229640A (ja) | スクリュー圧縮機 | |
JP7329772B2 (ja) | インジェクション機構付き圧縮機 | |
JP5321055B2 (ja) | 冷凍装置 | |
JP5835299B2 (ja) | 冷凍装置 | |
JP2003328968A (ja) | オイルフリースクリュ圧縮機 | |
JP2000111187A (ja) | 空気調和装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 13885804 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2015519557 Country of ref document: JP Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 1519248 Country of ref document: GB Kind code of ref document: A Free format text: PCT FILING DATE = 20130530 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1519248.7 Country of ref document: GB |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 13885804 Country of ref document: EP Kind code of ref document: A1 |