WO2018008052A1 - Screw compressor and refrigeration cycle device - Google Patents

Screw compressor and refrigeration cycle device Download PDF

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Publication number
WO2018008052A1
WO2018008052A1 PCT/JP2016/069740 JP2016069740W WO2018008052A1 WO 2018008052 A1 WO2018008052 A1 WO 2018008052A1 JP 2016069740 W JP2016069740 W JP 2016069740W WO 2018008052 A1 WO2018008052 A1 WO 2018008052A1
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WO
WIPO (PCT)
Prior art keywords
refrigerant
discharge port
screw
temperature
port valve
Prior art date
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PCT/JP2016/069740
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French (fr)
Japanese (ja)
Inventor
雅浩 神田
雅章 上川
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三菱電機株式会社
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Priority to PCT/JP2016/069740 priority Critical patent/WO2018008052A1/en
Publication of WO2018008052A1 publication Critical patent/WO2018008052A1/en

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    • 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
    • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
    • F04C29/12—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet

Definitions

  • the present invention relates to a refrigeration cycle apparatus having a screw compressor that compresses and discharges a fluid.
  • a screw compressor that compresses and discharges a fluid.
  • liquid compression in a screw compressor is prevented.
  • the screw compressor compresses low-temperature and low-pressure gaseous refrigerant (refrigerant gas) and discharges high-temperature and high-pressure refrigerant gas. Then, the condenser exchanges heat between the refrigerant gas and the external heat source so that the refrigerant gas becomes a high-pressure refrigerant liquid. Thereafter, the expansion valve squeezes and expands the high-pressure refrigerant liquid to obtain a low-temperature and low-pressure gas-liquid two-phase refrigerant.
  • refrigerant gas low-temperature and low-pressure gaseous refrigerant
  • the condenser exchanges heat between the refrigerant gas and the external heat source so that the refrigerant gas becomes a high-pressure refrigerant liquid.
  • the expansion valve squeezes and expands the high-pressure refrigerant liquid to obtain a low-temperature and low-pressure gas-liquid two-phase refrigerant.
  • the evaporator exchanges heat between the external heat source and the low-pressure gas-liquid two-phase refrigerant so that the low-pressure gas-liquid two-phase refrigerant becomes low-temperature and low-pressure refrigerant gas.
  • the low and low pressure refrigerant gas returns to the screw compressor.
  • the external heat source heat-exchanged with the low-pressure gas-liquid two-phase refrigerant in the evaporator has a low temperature.
  • thermometer and pressure gauge are input to the controller, and the saturation temperature and measured temperature at the measured pressure are Calculate the difference.
  • the superheat degree control which adjusts the opening degree of an expansion valve is performed so that measurement temperature may always become only a fixed value higher than saturation temperature (for example, refer patent document 1, 2).
  • the refrigerant liquid is prevented from flowing into the compressor by performing the superheat degree control for controlling the refrigerant to the superheated gas state.
  • the opening degree adjustment of the expansion valve cannot be followed.
  • the refrigerant liquid accumulates in the evaporator, eventually returning to the refrigerant liquid flowing into the compressor, and the gate rotor of the screw compressor may be damaged by the liquid compression. It was.
  • the present invention has been made to solve the above-described problems, and provides a screw compressor and a refrigeration cycle apparatus capable of suppressing breakage and the like even when refrigerant liquid returns to the compressor. With the goal.
  • a screw compressor includes a cylindrical casing main body, a screw rotor housed in an inner cylindrical surface of the casing main body and having a plurality of screw grooves on the outer peripheral surface, and a plurality of teeth meshed with the screw grooves.
  • a discharge port valve disposed between the casing main body, the casing main body and the screw rotor, wherein the discharge timing of the compressed refrigerant is changed according to the position in the direction of the rotation axis of the screw rotor; And a drive device that moves the discharge port valve according to the superheat temperature of the refrigerant flowing on the side.
  • the refrigeration cycle apparatus includes the above-described screw compressor, condenser, decompression device, and evaporator connected to each other to form a refrigerant circuit in which refrigerant is circulated, and overheating in the refrigerant flowing out of the evaporator
  • a discharge port valve control device that determines the position of the discharge port valve of the screw compressor according to the temperature is provided.
  • the drive device is arranged so that the discharge port valve is positioned at a position where the refrigerant discharge timing is advanced. Control.
  • the refrigeration cycle apparatus relates to a temperature detection device that detects a temperature on the refrigerant outflow side of the evaporator, a pressure detection device that detects a pressure on the refrigerant outflow side of the evaporator, and a detection of the temperature detection device.
  • An arithmetic device that calculates the superheat temperature from the temperature and the pressure related to detection by the pressure detection device is further provided.
  • the position of the discharge port valve is determined by the refrigerant overheating temperature, for example, when it is predicted that the refrigerant liquid has returned to the compression chamber, the discharge is performed.
  • the discharge timing can be advanced, the compression time can be reduced, and the pressure rise in the compression chamber can be suppressed. For this reason, the screw compressor is hardly damaged by liquid compression, and a highly reliable screw compressor and refrigeration cycle apparatus can be obtained.
  • FIG. (1) explaining the internal structure in the screw compressor 102 which concerns on Embodiment 1 of this invention.
  • FIG. (2) explaining the internal structure in the screw compressor 102 which concerns on Embodiment 1 of this invention.
  • FIG. (2) explaining the internal structure in the screw compressor 102 which concerns on Embodiment 1 of this invention.
  • FIG. (1) explaining the internal structure in the screw compressor 102 which concerns on Embodiment 1 of this invention.
  • FIG. (2) explaining the internal structure in the screw compressor 102 which concerns on Embodiment 1 of this invention.
  • FIG. 1 is a diagram showing a configuration of a refrigeration cycle apparatus 100 including a screw compressor 102 according to Embodiment 1 of the present invention.
  • the screw compressor 102 will be described as a device that constitutes a refrigerant circuit in which refrigerant is circulated.
  • the fluid that is sucked, compressed, and discharged by the screw compressor 102 according to the first embodiment will be described as a refrigerant that changes its state to gas and liquid.
  • the refrigeration cycle apparatus 100 in the first embodiment has a refrigerant circuit configured by connecting a screw compressor 102, a condenser 104, an expansion valve 105, and an evaporator 106 in order by refrigerant piping.
  • the inverter device 101 controls the power supply to the screw compressor 102 based on the instructed frequency, and controls the drive rotation speed of the screw compressor 102.
  • the screw compressor 102 is driven by electric power supplied via an inverter device 101 from a power supply source (not shown). The configuration of the screw compressor 102 will be described later.
  • the condenser 104 cools and condenses the refrigerant gas that is a gaseous refrigerant discharged from the screw compressor 102.
  • An expansion valve 105 serving as a decompression device decompresses and expands the refrigerant liquid that is a liquid refrigerant that has flowed out of the condenser 104.
  • the evaporator 106 evaporates the refrigerant that has passed through the expansion valve 105.
  • the refrigeration cycle apparatus 100 further includes a calculation device 107, a pressure sensor 108, a temperature sensor 109, and a control device 110.
  • the computing device 107 performs computation based on the input physical quantity data.
  • the refrigerant gas superheat temperature of the refrigerant flowing out of the evaporator 106 is calculated from the pressure data detected by the pressure sensor 108 and the temperature data detected by the temperature sensor 109.
  • a pressure sensor 108 serving as a pressure detection device and a temperature sensor 109 serving as a temperature detection device are installed on the refrigerant suction side of the screw compressor 102 and on the refrigerant outlet side of the evaporator 106 on the refrigerant outflow side.
  • the pressure sensor 108 detects the pressure of the refrigerant flowing out from the evaporator 106.
  • the temperature sensor 109 detects the temperature of the refrigerant flowing out of the evaporator 106.
  • the control device 110 controls the frequency of the inverter device 101, the opening degree of the expansion valve 105, and the like, and sends instructions to each device.
  • the control device 110 of the first embodiment has a discharge port valve control device 111.
  • the discharge port valve control device 111 performs position control of the discharge port valve 7 included in the screw compressor 102, as will be described later.
  • the screw compressor 102 sucks and compresses a refrigerant gas, which is a gaseous refrigerant, and then discharges it.
  • the discharge gas discharged from the screw compressor 102 is cooled by the condenser 104.
  • the refrigerant cooled by the condenser 104 is decompressed by the expansion valve 105.
  • the decompressed refrigerant is heated by the evaporator 106 and becomes refrigerant gas.
  • the refrigerant gas flowing out of the evaporator 106 is sucked into the screw compressor 102.
  • FIG. 2 and 3 are diagrams illustrating an internal configuration in screw compressor 102 according to Embodiment 1 of the present invention.
  • FIG. 2 is a view showing a state where the discharge port valve 7 accommodated in the inner cylinder surface of the casing body 1 is located on the discharge side in the rotation axis direction of the screw rotor 3.
  • FIG. 3 is a view showing a state where the discharge port valve 7 is located on the suction side of the screw rotor 3 in the rotation axis direction.
  • the screw compressor 102 according to the first embodiment is a single screw compressor provided with one screw rotor 3 and two gate rotors 6.
  • 2 and 3 are diagrams showing a configuration of a portion located on the upper side of the screw shaft 4 serving as a rotation shaft. The structure of the lower part of the screw shaft 4 is the same as that of the upper part.
  • the screw compressor 102 includes a casing body 1, a screw rotor 3, a gate rotor 6, a motor 2 that rotationally drives the screw rotor 3, a discharge port valve 7, and the like. ing.
  • the cylindrical casing body 1 accommodates the screw rotor 3, the gate rotor 6, the motor 2, the discharge port valve 7, and the like inside the cylinder.
  • the motor 2 includes a stator 2a that is inscribed and fixed to the casing body 1, and a motor rotor 2b that is disposed inside the stator 2a. The motor 2 is driven at a driving rotational speed based on the electric power supplied from the inverter device 101.
  • a screw rotor 3 is arranged in the casing body 1.
  • the screw rotor 3 and the motor rotor 2b are disposed and fixed around the screw shaft 4 serving as a rotation shaft.
  • the screw rotor 3 has a plurality of spiral screw grooves 5a formed on the outer peripheral surface thereof.
  • the screw rotor 3 rotates as the motor rotor 2b fixed to the screw shaft 4 rotates.
  • the screw compressor 102 according to the first embodiment has two gate rotors 6.
  • the two gate rotors 6 are symmetric with respect to the screw shaft 4 and are respectively disposed on both sides of the screw rotor 3.
  • the gate rotor 6 has a disk shape, and a plurality of teeth 6a are provided on the outer peripheral surface in the outer peripheral portion along the circumferential direction.
  • the teeth 6a of the gate rotor 6 are meshed with the screw grooves 5a.
  • a space surrounded by the teeth 6 a of the gate rotor 6, the screw groove 5 a, and the cylinder inner surface side of the casing body 1 becomes the compression chamber 5.
  • a plurality of compression chambers 5 are formed at positions that are point-symmetric with respect to the radial center of the screw rotor 3.
  • the inside of the screw compressor 102 is divided into a low pressure side which is a refrigerant suction side and a high pressure side which is a refrigerant discharge side by a partition wall (not shown).
  • the space on the low-pressure side is a low-pressure chamber (not shown) that serves as a suction pressure atmosphere.
  • the space on the high pressure side is a high pressure chamber (not shown) serving as a discharge pressure atmosphere.
  • a discharge port 10 is provided at a position on the high pressure side of the compression chamber 5 so as to communicate the discharge flow path 11 connected to the high pressure chamber and the compression chamber 5.
  • a slide groove 1 a extending in the direction of the rotation axis of the screw rotor 3 is formed at a position corresponding to the compression chamber 5 inside the casing body 1.
  • a discharge port valve 7 is accommodated in the slide groove 1a so as to be slidable along the slide groove 1a.
  • the discharge port valve 7 is integrated with the casing body 1 and forms a compression chamber 5 together with the casing body 1.
  • the discharge port valve 7 is connected to a drive device 9 such as a piston via a connecting rod 8.
  • a drive device 9 such as a piston
  • the discharge port valve 7 moves in the slide groove 1 a in the direction of the rotation axis of the screw rotor 3.
  • the driving device 9 for driving the discharge port valve 7 is not limited to a driving power source such as a device driven by a gas pressure, a device driven by a hydraulic pressure, a device driven by a motor or the like apart from a piston.
  • the internal volume ratio is a ratio between the volume of the compression chamber 5 at the time of completion of suction (start of compression) and the volume of the compression chamber 5 just before discharge from the discharge port 10. The internal volume ratio is changed by adjusting the timing at which the refrigerant is discharged from the discharge port 10.
  • an inappropriate compression loss does not occur when the actual compression ratio is an operation condition of an appropriate compression ratio that matches the internal volume ratio.
  • the time until the compression chamber 5 reaches the position of the discharge port 10 is long, and the compressed refrigerant gas is over-compressed to the discharge pressure or higher. For this reason, the screw compressor 102 performs extra compression work.
  • the time until the compression chamber 5 reaches the position of the discharge port 10 is short, the discharge port 10 opens before reaching the discharge pressure, and the refrigerant gas flows backward. Will result in insufficient compression. Therefore, the position of the discharge port valve 7 is adjusted so that the discharge start timing is optimal.
  • FIG. 4 is a diagram illustrating a compression principle of the screw compressor 102 according to the first embodiment of the present invention.
  • the operation of the screw compressor 102 according to Embodiment 1 will be described.
  • the screw rotor 3 is rotated by the motor 2 shown in FIGS. 2 and 3 via the screw shaft 4 shown in FIGS. 2 and 3, the teeth 6a of the gate rotor 6 are moved as shown in FIG. It moves relatively in the compression chamber 5 (screw groove 5a).
  • a suction stroke, a compression stroke, and a discharge stroke are sequentially performed.
  • the cycle is repeated with the suction stroke, compression stroke, and discharge stroke as one cycle.
  • each stroke will be described.
  • the discharge port valve 7 and the slide groove 1a are not shown.
  • FIG. 4A shows the state of the compression chamber 5 in the suction stroke.
  • the screw rotor 3 is driven by the motor 2 and rotates in the direction of the solid arrow.
  • the volume of the compression chamber 5 decreases as shown in FIG.
  • the compression chamber 5 communicates with the outside through the discharge flow path 11 as shown in FIG. Thereby, the high-pressure refrigerant gas compressed in the compression chamber 5 is discharged from the discharge passage 11 to the outside. Then, the same compression is performed again on the back surface of the screw rotor 3.
  • FIG. 5 is a diagram showing a flowchart relating to the position control of the discharge port valve 7 of the screw compressor 102 according to Embodiment 1 of the present invention.
  • the position control of the discharge port valve 7 performed by the control device 110 will be described based on FIG.
  • the arithmetic unit 107 calculates the refrigerant gas overheating temperature based on the pressure detected by the pressure sensor 108 and the temperature detected by the temperature sensor 109.
  • the control device 110 determines whether or not the refrigerant gas superheat temperature calculated by the arithmetic device 107 is lower than a preset target refrigerant gas superheat temperature A (step S1).
  • the controller 110 determines that the calculated refrigerant gas superheat temperature is equal to or higher than the target refrigerant gas superheat temperature A
  • the discharge port 10 is placed at an arbitrary position according to the operating state of the refrigeration cycle apparatus 100 as shown in FIG.
  • the discharge port valve 7 is moved so that is positioned (step S2). For example, the screw compressor 102 is moved to a position where the operating efficiency is highest.
  • step S1 when the controller 110 determines in step S1 that the calculated refrigerant gas superheat temperature is lower than the target refrigerant gas superheat temperature A, the position of the discharge port 10 is the lowest internal volume as shown in FIG.
  • the discharge port valve 7 is moved so as to reach the suction side position that is the ratio (step S3).
  • step S3 when the discharge port valve 7 is located at the lowest internal volume ratio, the control device 110 determines whether or not the refrigerant gas superheat temperature is lower than the preset target refrigerant gas superheat temperature B. (Step S4). When the control device 110 determines that the refrigerant gas superheat temperature is lower than the target refrigerant gas superheat temperature B, the control device 110 returns to step S3 and continues to position the discharge port valve 7 at the suction side position where the lowest internal volume ratio is obtained. Let Here, the target refrigerant gas superheat temperature A ⁇ the target refrigerant gas superheat temperature B.
  • step S4 when the control device 110 determines in step S4 that the refrigerant gas superheat temperature is equal to or higher than the target refrigerant gas superheat temperature B, the control device 110 transitions to step S2 and takes an arbitrary position according to the operating state of the refrigeration cycle apparatus 100.
  • the discharge port valve 7 is moved so that the discharge port 10 is located.
  • the screw compressor 102 includes the discharge port valve 7 that adjusts the discharge timing of the refrigerant gas from the compression chamber 5, and the control device 110 includes: If it is determined that the refrigerant gas superheat temperature is lower than the target refrigerant gas superheat temperature, the discharge port valve 7 is moved to the suction side that has the lowest internal volume ratio, and the pressure increase in the compression stroke in the compression chamber 5 is reduced. Since it did in this way, even if refrigerant liquid returns in the screw compressor 102, damage to the gate rotor 6 etc. by the liquid compression in the compression chamber 5 can be suppressed. For this reason, the highly reliable screw compressor 102 and the refrigeration cycle apparatus 100 can be obtained. In addition, an accumulator that is connected to the refrigerant suction side of the screw compressor 102 and accumulates the refrigerant liquid is unnecessary or can be configured as a small accumulator.
  • Embodiment 2 FIG.
  • the screw compressor 102 has been described as a single screw compressor.
  • the present invention is not limited to this.
  • the present invention can also be applied to a twin screw compressor in which a compression chamber is formed by meshing grooves of two screw rotors.
  • the present invention can also be applied to a mono-gate rotor type screw compressor in which one gate rotor 6 is arranged.
  • the pressure sensor 108 and the temperature sensor 109 are provided at the outlet of the evaporator 106, but the refrigerant is sucked into the compression chamber 5 of the screw compressor 102 from the outlet of the evaporator 106. It may be provided anywhere between.
  • the saturation temperature in the pressure and the refrigerant gas superheating temperature which is the difference between the temperatures are calculated.
  • the refrigerant liquid may return to the compression chamber 5 even if the calculated refrigerant gas overheating temperature is 0 ° C. or higher. Therefore, by setting the target refrigerant gas superheat temperature A to, for example, 3 ° C., the screw compressor 102 and the refrigeration cycle apparatus 100 can be obtained with high reliability by suppressing damage to the screw compressor 102. Can do.
  • the refrigeration apparatus has been described as an example of the refrigeration cycle apparatus, but the present invention is not limited to this.
  • the present invention can be applied to other refrigeration cycle apparatuses such as an air conditioner, a refrigerator, and a refrigeration apparatus.
  • 1 casing body 1a slide groove, 2 motor, 2a stator, 2b motor rotor, 3 screw rotor, 4 screw shaft, 5 compression chamber, 5a screw groove, 6 gate rotor, 6a teeth, 7 discharge port valve, 8 connecting rod, 9 Drive device, 10 discharge port, 11 discharge flow path, 100 refrigeration cycle device, 101 inverter device, 102 screw compressor, 104 condenser, 105 expansion valve, 106 evaporator, 107 arithmetic device, 108 pressure sensor, 109 temperature sensor, 110 control device, 111 discharge port valve control device.

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  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)

Abstract

The screw compressor pertaining to the present invention comprises: a cylindrical casing body; a screw rotor which is housed by an inner cylindrical surface of the casing body and which has multiple screw grooves on the outer peripheral surface thereof; a gate rotor which has multiple teeth arranged on the outer periphery thereof and engaging with the screw grooves; a discharge port valve which is disposed between the casing body and the screw rotor in such a manner that the timing of discharging a compressed refrigerant changes in accordance with the position of the valve in the direction of the rotation axis of the screw rotor; and a drive device which causes the discharge port valve to move in accordance with a superheated temperature of the refrigerant flowing on the suction side.

Description

スクリュー圧縮機および冷凍サイクル装置Screw compressor and refrigeration cycle equipment
　本発明は、流体を圧縮して吐出するスクリュー圧縮機を有する冷凍サイクル装置に関するものである。特に、スクリュー圧縮機における液圧縮を防止するものである。 The present invention relates to a refrigeration cycle apparatus having a screw compressor that compresses and discharges a fluid. In particular, liquid compression in a screw compressor is prevented.
　たとえば、スクリュー圧縮機を搭載する冷凍装置では、スクリュー圧縮機が、低温および低圧のガス状の冷媒（冷媒ガス）を圧縮して、高温および高圧の冷媒ガスを吐出する。そして、凝縮器が、冷媒ガスと外部熱源とを熱交換させて、冷媒ガスを高圧の冷媒液とする。その後、膨張弁が高圧の冷媒液を絞り膨張させて、低温および低圧の気液二相状態の冷媒とする。蒸発器が、外部熱源と低圧の気液二相状態の冷媒とを熱交換させて、低圧の気液二相状態の冷媒を、低温および低圧の冷媒ガスにする。低温および低圧の冷媒ガスは、スクリュー圧縮機に戻る。一方、蒸発器において低圧の気液二相状態の冷媒と熱交換された外部熱源は、低温となる。 For example, in a refrigeration apparatus equipped with a screw compressor, the screw compressor compresses low-temperature and low-pressure gaseous refrigerant (refrigerant gas) and discharges high-temperature and high-pressure refrigerant gas. Then, the condenser exchanges heat between the refrigerant gas and the external heat source so that the refrigerant gas becomes a high-pressure refrigerant liquid. Thereafter, the expansion valve squeezes and expands the high-pressure refrigerant liquid to obtain a low-temperature and low-pressure gas-liquid two-phase refrigerant. The evaporator exchanges heat between the external heat source and the low-pressure gas-liquid two-phase refrigerant so that the low-pressure gas-liquid two-phase refrigerant becomes low-temperature and low-pressure refrigerant gas. The low and low pressure refrigerant gas returns to the screw compressor. On the other hand, the external heat source heat-exchanged with the low-pressure gas-liquid two-phase refrigerant in the evaporator has a low temperature.
　このような冷凍装置では、蒸発器の冷媒出口側における冷媒を過熱冷媒ガス状態に保持するため、温度計および圧力計における測定値を調節計に入力し、測定圧力における飽和温度と測定温度との差を演算する。そして、測定温度が常に飽和温度よりも一定値だけ高くなるように、膨張弁の開度を調整する過熱度制御を行う（たとえば、特許文献１、２参照）。 In such a refrigeration apparatus, in order to maintain the refrigerant on the refrigerant outlet side of the evaporator in a superheated refrigerant gas state, the measured values in the thermometer and pressure gauge are input to the controller, and the saturation temperature and measured temperature at the measured pressure are Calculate the difference. And the superheat degree control which adjusts the opening degree of an expansion valve is performed so that measurement temperature may always become only a fixed value higher than saturation temperature (for example, refer patent document 1, 2).
特開平４－０３９５７３号公報Japanese Patent Laid-Open No. 4-039573 特開平６－２１３５１５号公報JP-A-6-213515
　上記の特許文献の装置では、冷媒を過熱ガス状態に制御する過熱度制御を行うことで、圧縮機内に冷媒液が流入することを防止している。しかしながら、たとえば、冷凍装置の運転状態が急激に変化した場合などにおいては、膨張弁の開度調整を追従させることができなくなる。このため、蒸発器内に冷媒液が溜まってしまい、遂には圧縮機内に冷媒液が流入する冷媒液戻りが発生し、スクリュー圧縮機のゲートロータなどが液圧縮によって破損してしまう可能性があった。 In the apparatus of the above-mentioned patent document, the refrigerant liquid is prevented from flowing into the compressor by performing the superheat degree control for controlling the refrigerant to the superheated gas state. However, for example, when the operating state of the refrigeration apparatus changes abruptly, the opening degree adjustment of the expansion valve cannot be followed. As a result, the refrigerant liquid accumulates in the evaporator, eventually returning to the refrigerant liquid flowing into the compressor, and the gate rotor of the screw compressor may be damaged by the liquid compression. It was.
　本発明は、上記のような課題を解決するためになされたものであり、圧縮機に冷媒液戻りが生じた場合でも、破損などを抑制することができるスクリュー圧縮機および冷凍サイクル装置を得ることを目的とする。 The present invention has been made to solve the above-described problems, and provides a screw compressor and a refrigeration cycle apparatus capable of suppressing breakage and the like even when refrigerant liquid returns to the compressor. With the goal.
　本発明に係るスクリュー圧縮機は、筒状のケーシング本体と、ケーシング本体の内筒面に収容され、複数のスクリュー溝を外周面に有するスクリューロータと、スクリュー溝に噛み合わされる複数の歯が外周部に配置されたゲートロータと、ケーシング本体とスクリューロータとの間にあって、スクリューロータの回転軸の方向における位置に応じて、圧縮された冷媒を吐出するタイミングが変更される吐出ポート弁と、吸入側を流れる冷媒の過熱温度により、吐出ポート弁を移動させる駆動装置とを備えるものである。 A screw compressor according to the present invention includes a cylindrical casing main body, a screw rotor housed in an inner cylindrical surface of the casing main body and having a plurality of screw grooves on the outer peripheral surface, and a plurality of teeth meshed with the screw grooves. A discharge port valve disposed between the casing main body, the casing main body and the screw rotor, wherein the discharge timing of the compressed refrigerant is changed according to the position in the direction of the rotation axis of the screw rotor; And a drive device that moves the discharge port valve according to the superheat temperature of the refrigerant flowing on the side.
　また、本発明に係る冷凍サイクル装置は、上記のスクリュー圧縮機、凝縮器、減圧装置および蒸発器が配管接続され、冷媒の循環が行われる冷媒回路が構成され、蒸発器から流出する冷媒における過熱温度により、スクリュー圧縮機が有する吐出ポート弁の位置を決める吐出ポート弁制御装置を備えるものである。 Further, the refrigeration cycle apparatus according to the present invention includes the above-described screw compressor, condenser, decompression device, and evaporator connected to each other to form a refrigerant circuit in which refrigerant is circulated, and overheating in the refrigerant flowing out of the evaporator A discharge port valve control device that determines the position of the discharge port valve of the screw compressor according to the temperature is provided.
　さらに、本発明に係る冷凍サイクル装置の吐出ポート弁制御装置は、過熱温度が目標よりも低いと判定すると、冷媒を吐出するタイミングが早くなる位置に、吐出ポート弁を位置させるように駆動装置を制御する。 Further, when the discharge port valve control device of the refrigeration cycle apparatus according to the present invention determines that the superheat temperature is lower than the target, the drive device is arranged so that the discharge port valve is positioned at a position where the refrigerant discharge timing is advanced. Control.
　そして、本発明に係る冷凍サイクル装置は、蒸発器の冷媒流出側における温度を検出する温度検出装置と、蒸発器の冷媒流出側における圧力を検出する圧力検出装置と、温度検出装置の検出に係る温度と圧力検出装置の検出に係る圧力とから過熱温度を演算する演算装置とをさらに備える。 The refrigeration cycle apparatus according to the present invention relates to a temperature detection device that detects a temperature on the refrigerant outflow side of the evaporator, a pressure detection device that detects a pressure on the refrigerant outflow side of the evaporator, and a detection of the temperature detection device. An arithmetic device that calculates the superheat temperature from the temperature and the pressure related to detection by the pressure detection device is further provided.
　本発明によれば、スクリュー圧縮機において、冷媒の過熱温度によって、吐出ポート弁の位置が決められるようにすることで、たとえば、圧縮室内へ冷媒液戻りが生じていると予測されるときには、吐出ポート弁を吸込側に位置させることで、吐出タイミングを早くすることができ、圧縮時間が減って、圧縮室内における圧力上昇を抑制することができる。このため、液圧縮によるスクリュー圧縮機の破損が生じにくくなり、信頼性の高いスクリュー圧縮機および冷凍サイクル装置を得ることができる。 According to the present invention, in the screw compressor, the position of the discharge port valve is determined by the refrigerant overheating temperature, for example, when it is predicted that the refrigerant liquid has returned to the compression chamber, the discharge is performed. By positioning the port valve on the suction side, the discharge timing can be advanced, the compression time can be reduced, and the pressure rise in the compression chamber can be suppressed. For this reason, the screw compressor is hardly damaged by liquid compression, and a highly reliable screw compressor and refrigeration cycle apparatus can be obtained.
本発明の実施の形態１に係るスクリュー圧縮機１０２を備える冷凍サイクル装置１００の構成を示す図である。It is a figure which shows the structure of the refrigerating-cycle apparatus 100 provided with the screw compressor 102 which concerns on Embodiment 1 of this invention. 本発明の実施の形態１に係るスクリュー圧縮機１０２における内部構成を説明する図（その１）である。It is FIG. (1) explaining the internal structure in the screw compressor 102 which concerns on Embodiment 1 of this invention. 本発明の実施の形態１に係るスクリュー圧縮機１０２における内部構成を説明する図（その２）である。It is FIG. (2) explaining the internal structure in the screw compressor 102 which concerns on Embodiment 1 of this invention. 本発明の実施の形態１に係るスクリュー圧縮機１０２の圧縮原理を示す図である。It is a figure which shows the compression principle of the screw compressor 102 which concerns on Embodiment 1 of this invention. 本発明の実施の形態１におけるスクリュー圧縮機１０２の吐出ポート弁７の位置制御に係るフローチャートを示す図である。It is a figure which shows the flowchart which concerns on the position control of the discharge port valve 7 of the screw compressor 102 in Embodiment 1 of this invention.
　以下、本発明の実施の形態について、図面を参照しつつ説明する。ここで、以下の図面において、同一の符号を付したものは、同一またはこれに相当するものであり、以下に記載する実施の形態の全文において共通することとする。また、明細書全文に示さ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。特に構成要素の組み合わせは、各実施の形態における組み合わせのみに限定するものではなく、他の実施の形態に記載した構成要素を別の実施の形態に適宜、適用することができる。そして、圧力の高低については、特に絶対的な値との関係で高低が定まっているものではなく、システム、装置などにおける状態、動作などにおいて相対的に定まるものとする。また、添字で区別などしている複数の同種の機器などについて、特に区別したり、特定したりする必要がない場合には、添字などを省略して記載する場合がある。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, in the following drawings, what attached | subjected the same code | symbol is the same or it corresponds, and shall be common in the whole sentence of embodiment described below. Moreover, the form of the component shown by the whole specification is an illustration to the last, and is not limited to these description. In particular, the combination of the constituent elements is not limited to the combination in each embodiment, and the constituent elements described in the other embodiments can be applied to other embodiments as appropriate. The pressure level is not particularly determined in relation to the absolute value, but is relatively determined in terms of the state and operation of the system and apparatus. In addition, when there is no need to distinguish or identify a plurality of similar devices that are distinguished by subscripts, the subscripts may be omitted.
実施の形態１．
　図１は、本発明の実施の形態１に係るスクリュー圧縮機１０２を備える冷凍サイクル装置１００の構成を示す図である。以下において、スクリュー圧縮機１０２は、冷媒の循環が行われる冷媒回路を構成する機器であるものとして説明する。このため、実施の形態１などのスクリュー圧縮機１０２が吸入、圧縮および吐出する流体は、気体および液体に状態変化する冷媒であるものとして説明する。 Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a refrigeration cycle apparatus 100 including a screw compressor 102 according to Embodiment 1 of the present invention. In the following description, the screw compressor 102 will be described as a device that constitutes a refrigerant circuit in which refrigerant is circulated. For this reason, the fluid that is sucked, compressed, and discharged by the screw compressor 102 according to the first embodiment will be described as a refrigerant that changes its state to gas and liquid.
　実施の形態１における冷凍サイクル装置１００は、スクリュー圧縮機１０２と、凝縮器１０４と、膨張弁１０５と、蒸発器１０６とを順に冷媒配管で接続して構成した冷媒回路を有している。 The refrigeration cycle apparatus 100 in the first embodiment has a refrigerant circuit configured by connecting a screw compressor 102, a condenser 104, an expansion valve 105, and an evaporator 106 in order by refrigerant piping.
　インバータ装置１０１は、指示された周波数に基づいてスクリュー圧縮機１０２への電力供給を制御して、スクリュー圧縮機１０２の駆動回転数を制御する。スクリュー圧縮機１０２は、電力供給源（図示せず）から、インバータ装置１０１を介して供給された電力で駆動する。スクリュー圧縮機１０２の構成などについては後述する。凝縮器１０４は、スクリュー圧縮機１０２が吐出したガス状の冷媒である冷媒ガスを冷却し、凝縮させる。また、減圧装置となる膨張弁１０５は凝縮器１０４から流出した液状の冷媒である冷媒液を減圧させ、膨張させる。蒸発器１０６は、膨張弁１０５を通過した冷媒を蒸発させる。 The inverter device 101 controls the power supply to the screw compressor 102 based on the instructed frequency, and controls the drive rotation speed of the screw compressor 102. The screw compressor 102 is driven by electric power supplied via an inverter device 101 from a power supply source (not shown). The configuration of the screw compressor 102 will be described later. The condenser 104 cools and condenses the refrigerant gas that is a gaseous refrigerant discharged from the screw compressor 102. An expansion valve 105 serving as a decompression device decompresses and expands the refrigerant liquid that is a liquid refrigerant that has flowed out of the condenser 104. The evaporator 106 evaporates the refrigerant that has passed through the expansion valve 105.
　冷凍サイクル装置１００は、さらに、演算装置１０７、圧力センサー１０８および温度センサー１０９並びに制御装置１１０を備えている。演算装置１０７は、入力される物理量のデータに基づいて演算を行う。特に、実施の形態１では、圧力センサー１０８が検出した圧力のデータおよび温度センサー１０９が検出した温度のデータから、蒸発器１０６から流出する冷媒の冷媒ガス過熱温度を演算する。 The refrigeration cycle apparatus 100 further includes a calculation device 107, a pressure sensor 108, a temperature sensor 109, and a control device 110. The computing device 107 performs computation based on the input physical quantity data. In particular, in the first embodiment, the refrigerant gas superheat temperature of the refrigerant flowing out of the evaporator 106 is calculated from the pressure data detected by the pressure sensor 108 and the temperature data detected by the temperature sensor 109.
　圧力検出装置となる圧力センサー１０８および温度検出装置となる温度センサー１０９は、スクリュー圧縮機１０２の冷媒吸入側であり、蒸発器１０６の冷媒流出側となる冷媒出口に設置される。そして、圧力センサー１０８は、蒸発器１０６から流出する冷媒の圧力を検出する。また、温度センサー１０９は、蒸発器１０６から流出する冷媒の温度を検出する。 A pressure sensor 108 serving as a pressure detection device and a temperature sensor 109 serving as a temperature detection device are installed on the refrigerant suction side of the screw compressor 102 and on the refrigerant outlet side of the evaporator 106 on the refrigerant outflow side. The pressure sensor 108 detects the pressure of the refrigerant flowing out from the evaporator 106. The temperature sensor 109 detects the temperature of the refrigerant flowing out of the evaporator 106.
　制御装置１１０は、インバータ装置１０１の周波数、膨張弁１０５の開度などを制御し、各機器に指示を送る。特に、実施の形態１の制御装置１１０は、吐出ポート弁制御装置１１１を有している。吐出ポート弁制御装置１１１は、後述するように、スクリュー圧縮機１０２が有する吐出ポート弁７の位置制御などを行う。 The control device 110 controls the frequency of the inverter device 101, the opening degree of the expansion valve 105, and the like, and sends instructions to each device. In particular, the control device 110 of the first embodiment has a discharge port valve control device 111. The discharge port valve control device 111 performs position control of the discharge port valve 7 included in the screw compressor 102, as will be described later.
（冷媒回路の動作説明）
　次に、図１に基づいて、実施の形態１の冷凍サイクル装置１００の動作について説明する。スクリュー圧縮機１０２は、ガス状の冷媒である冷媒ガスを吸込して圧縮した後、吐出する。スクリュー圧縮機１０２から吐出された吐出ガスは、凝縮器１０４で冷却される。凝縮器１０４で冷却された冷媒は、膨張弁１０５で減圧される。減圧された冷媒は、蒸発器１０６で加熱され、冷媒ガスとなる。蒸発器１０６から流出した冷媒ガスはスクリュー圧縮機１０２に吸い込まれる。 (Explanation of refrigerant circuit operation)
Next, based on FIG. 1, operation | movement of the refrigerating-cycle apparatus 100 of Embodiment 1 is demonstrated. The screw compressor 102 sucks and compresses a refrigerant gas, which is a gaseous refrigerant, and then discharges it. The discharge gas discharged from the screw compressor 102 is cooled by the condenser 104. The refrigerant cooled by the condenser 104 is decompressed by the expansion valve 105. The decompressed refrigerant is heated by the evaporator 106 and becomes refrigerant gas. The refrigerant gas flowing out of the evaporator 106 is sucked into the screw compressor 102.
（スクリュー圧縮機）
　図２および図３は、本発明の実施の形態１に係るスクリュー圧縮機１０２における内部構成を説明する図である。図２は、ケーシング本体１の内筒面に収容された吐出ポート弁７が、スクリューロータ３の回転軸方向の吐出側に位置している状態を示す図である。また、図３は、吐出ポート弁７が、スクリューロータ３の回転軸方向の吸込側に位置している状態を示す図である。ここで、実施の形態１のスクリュー圧縮機１０２は、１つのスクリューロータ３と２つのゲートロータ６とを備えたシングルスクリュー圧縮機であるものとする。そして、図２および図３では、回転軸となるスクリュー軸４の上側に位置する部分の構成を示す図となっている。スクリュー軸４の下側における部分の構成も、上側における部分と同様の構成である。 (Screw compressor)
2 and 3 are diagrams illustrating an internal configuration in screw compressor 102 according to Embodiment 1 of the present invention. FIG. 2 is a view showing a state where the discharge port valve 7 accommodated in the inner cylinder surface of the casing body 1 is located on the discharge side in the rotation axis direction of the screw rotor 3. FIG. 3 is a view showing a state where the discharge port valve 7 is located on the suction side of the screw rotor 3 in the rotation axis direction. Here, the screw compressor 102 according to the first embodiment is a single screw compressor provided with one screw rotor 3 and two gate rotors 6. 2 and 3 are diagrams showing a configuration of a portion located on the upper side of the screw shaft 4 serving as a rotation shaft. The structure of the lower part of the screw shaft 4 is the same as that of the upper part.
　図２および図３に示すように、実施の形態１のスクリュー圧縮機１０２は、ケーシング本体１、スクリューロータ３、ゲートロータ６、スクリューロータ３を回転駆動させるモータ２、吐出ポート弁７などを備えている。筒状のケーシング本体１は、スクリューロータ３、ゲートロータ６、モータ２、吐出ポート弁７などを筒の内側に収容する。モータ２は、ケーシング本体１に内接固定されたステータ２ａと、ステータ２ａの内側に配置されたモータロータ２ｂとを備えている。モータ２は、インバータ装置１０１から供給された電力に基づく駆動回転数で駆動する。 As shown in FIGS. 2 and 3, the screw compressor 102 according to the first embodiment includes a casing body 1, a screw rotor 3, a gate rotor 6, a motor 2 that rotationally drives the screw rotor 3, a discharge port valve 7, and the like. ing. The cylindrical casing body 1 accommodates the screw rotor 3, the gate rotor 6, the motor 2, the discharge port valve 7, and the like inside the cylinder. The motor 2 includes a stator 2a that is inscribed and fixed to the casing body 1, and a motor rotor 2b that is disposed inside the stator 2a. The motor 2 is driven at a driving rotational speed based on the electric power supplied from the inverter device 101.
　また、ケーシング本体１内にはスクリューロータ３が配置されている。スクリューロータ３とモータロータ２ｂとは、互いに、回転軸となるスクリュー軸４の周りに配置され、固定されている。スクリューロータ３は、外周面に複数の螺旋状のスクリュー溝５ａが形成されている。スクリューロータ３は、スクリュー軸４に固定されたモータロータ２ｂの回転に伴って回転する。また、実施の形態１のスクリュー圧縮機１０２は、２つのゲートロータ６を有している。２つのゲートロータ６は、スクリュー軸４に対して対称となる位置であって、スクリューロータ３の両側にそれぞれ配置されている。ゲートロータ６は、円板状の形状をしており、外周部分にある外周面には周方向に沿って複数の歯６ａが設けられている。ゲートロータ６の歯６ａは、スクリュー溝５ａに噛み合わされている。そして、ゲートロータ６の歯６ａ、スクリュー溝５ａおよびケーシング本体１の筒内面側によって囲まれた空間が圧縮室５となる。圧縮室５は、スクリューロータ３の径方向中心に対して、点対称となる位置に複数形成される。 Further, a screw rotor 3 is arranged in the casing body 1. The screw rotor 3 and the motor rotor 2b are disposed and fixed around the screw shaft 4 serving as a rotation shaft. The screw rotor 3 has a plurality of spiral screw grooves 5a formed on the outer peripheral surface thereof. The screw rotor 3 rotates as the motor rotor 2b fixed to the screw shaft 4 rotates. Further, the screw compressor 102 according to the first embodiment has two gate rotors 6. The two gate rotors 6 are symmetric with respect to the screw shaft 4 and are respectively disposed on both sides of the screw rotor 3. The gate rotor 6 has a disk shape, and a plurality of teeth 6a are provided on the outer peripheral surface in the outer peripheral portion along the circumferential direction. The teeth 6a of the gate rotor 6 are meshed with the screw grooves 5a. A space surrounded by the teeth 6 a of the gate rotor 6, the screw groove 5 a, and the cylinder inner surface side of the casing body 1 becomes the compression chamber 5. A plurality of compression chambers 5 are formed at positions that are point-symmetric with respect to the radial center of the screw rotor 3.
　ここで、スクリュー圧縮機１０２内は、隔壁（図示せず）により冷媒の吸込側となる低圧側と冷媒の吐出側となる高圧側とに区画される。低圧側の空間は、吸込圧力雰囲気となる低圧室（図示せず）となる。また、高圧側の空間は、吐出圧力雰囲気となる高圧室（図示せず）となる。ケーシング本体１において、圧縮室５の高圧側となる位置には、高圧室に連なる吐出流路１１と圧縮室５とを連通させる吐出口１０が設けられている。 Here, the inside of the screw compressor 102 is divided into a low pressure side which is a refrigerant suction side and a high pressure side which is a refrigerant discharge side by a partition wall (not shown). The space on the low-pressure side is a low-pressure chamber (not shown) that serves as a suction pressure atmosphere. The space on the high pressure side is a high pressure chamber (not shown) serving as a discharge pressure atmosphere. In the casing body 1, a discharge port 10 is provided at a position on the high pressure side of the compression chamber 5 so as to communicate the discharge flow path 11 connected to the high pressure chamber and the compression chamber 5.
　さらに、ケーシング本体１の内側において、圧縮室５に対応する位置に、スクリューロータ３の回転軸方向に延びるスライド溝１ａが形成されている。そして、スライド溝１ａ内には吐出ポート弁７が、スライド溝１ａに沿ってスライド移動自在に収容されている。吐出ポート弁７は、ケーシング本体１と一体となって、ケーシング本体１とともに圧縮室５を形成している。 Furthermore, a slide groove 1 a extending in the direction of the rotation axis of the screw rotor 3 is formed at a position corresponding to the compression chamber 5 inside the casing body 1. A discharge port valve 7 is accommodated in the slide groove 1a so as to be slidable along the slide groove 1a. The discharge port valve 7 is integrated with the casing body 1 and forms a compression chamber 5 together with the casing body 1.
　吐出ポート弁７は、連結棒８を介して、たとえば、ピストンなどの駆動装置９に接続されている。駆動装置９を駆動させることにより、吐出ポート弁７は、スライド溝１ａ内を、スクリューロータ３の回転軸方向に移動する。吐出ポート弁７が移動することにより、圧縮室５で圧縮される冷媒が吐出口１０から吐出開始されるタイミングが調整される。ここで、吐出ポート弁７を駆動する駆動装置９は、ガス圧で駆動するもの、油圧で駆動するもの、ピストンとは別に、モータなどにより駆動するものなど、駆動の動力源は限定しない。 The discharge port valve 7 is connected to a drive device 9 such as a piston via a connecting rod 8. By driving the drive device 9, the discharge port valve 7 moves in the slide groove 1 a in the direction of the rotation axis of the screw rotor 3. When the discharge port valve 7 moves, the timing at which the refrigerant compressed in the compression chamber 5 starts to be discharged from the discharge port 10 is adjusted. Here, the driving device 9 for driving the discharge port valve 7 is not limited to a driving power source such as a device driven by a gas pressure, a device driven by a hydraulic pressure, a device driven by a motor or the like apart from a piston.
　吐出ポート弁７をスクリューロータ３の回転軸方向の吸込側へ移動させると、吐出開始のタイミングが早まる低内部容積比の運転となる。また、吐出ポート弁７をスクリューロータ３の回転軸方向の吐出側へ移動させると、吐出開始のタイミングが遅くなる高内部容積比の運転となる。ここで、内部容積比とは、吸込完了（圧縮開始）時の圧縮室５の容積と吐出口１０から吐出寸前の圧縮室５の容積との比である。内部容積比の変更は、冷媒が吐出口１０から吐出されるタイミングを調整することで行う。 When the discharge port valve 7 is moved to the suction side of the screw rotor 3 in the rotation axis direction, the operation of a low internal volume ratio is achieved in which the discharge start timing is advanced. Further, when the discharge port valve 7 is moved to the discharge side of the screw rotor 3 in the direction of the rotation axis, the operation of high internal volume ratio is performed in which the discharge start timing is delayed. Here, the internal volume ratio is a ratio between the volume of the compression chamber 5 at the time of completion of suction (start of compression) and the volume of the compression chamber 5 just before discharge from the discharge port 10. The internal volume ratio is changed by adjusting the timing at which the refrigerant is discharged from the discharge port 10.
　一般的に、スクリュー圧縮機１０２では、実際の圧縮比が内部容積比に見合う適正圧縮比の運転条件の場合には、不適正な圧縮損失は生じない。しかし、低内部圧縮比の運転を行うと、圧縮室５が吐出口１０の位置に到達するまでの時間が長く、圧縮された冷媒ガスは吐出圧力以上に過圧縮される。このため、スクリュー圧縮機１０２は、余分な圧縮仕事を行うことになる。また、逆に、高内部圧縮比の運転を行うと、圧縮室５が吐出口１０の位置に到達するまでの時間が短く、吐出圧力に到達する前に吐出口１０が開き、冷媒ガスの逆流を生じる圧縮不足の状態となる。そこで、吐出開始のタイミングが最適となるように、吐出ポート弁７の位置が調整される。 Generally, in the screw compressor 102, an inappropriate compression loss does not occur when the actual compression ratio is an operation condition of an appropriate compression ratio that matches the internal volume ratio. However, when an operation with a low internal compression ratio is performed, the time until the compression chamber 5 reaches the position of the discharge port 10 is long, and the compressed refrigerant gas is over-compressed to the discharge pressure or higher. For this reason, the screw compressor 102 performs extra compression work. Conversely, when an operation with a high internal compression ratio is performed, the time until the compression chamber 5 reaches the position of the discharge port 10 is short, the discharge port 10 opens before reaching the discharge pressure, and the refrigerant gas flows backward. Will result in insufficient compression. Therefore, the position of the discharge port valve 7 is adjusted so that the discharge start timing is optimal.
（スクリュー圧縮機１０２の動作説明）
　図４は、本発明の実施の形態１に係るスクリュー圧縮機１０２の圧縮原理を示す図である。次に、実施の形態１に係るスクリュー圧縮機１０２の動作について説明する。たとえば、スクリューロータ３が、図２および図３に示すモータ２により、図２および図３に示すスクリュー軸４を介して回転させられると、図４に示すように、ゲートロータ６の歯６ａが圧縮室５（スクリュー溝５ａ）内を相対的に移動する。このとき、圧縮室５内では、吸込行程、圧縮行程および吐出行程が順次行われる。吸込行程、圧縮行程および吐出行程を１つのサイクルとして、サイクルが繰り返される。ここでは、図４においてドット状のハッチングで示した圧縮室５に着目して、各行程について説明する。ここで、図４では、吐出ポート弁７およびスライド溝１ａについては図示を省略している。 (Description of operation of screw compressor 102)
FIG. 4 is a diagram illustrating a compression principle of the screw compressor 102 according to the first embodiment of the present invention. Next, the operation of the screw compressor 102 according to Embodiment 1 will be described. For example, when the screw rotor 3 is rotated by the motor 2 shown in FIGS. 2 and 3 via the screw shaft 4 shown in FIGS. 2 and 3, the teeth 6a of the gate rotor 6 are moved as shown in FIG. It moves relatively in the compression chamber 5 (screw groove 5a). At this time, in the compression chamber 5, a suction stroke, a compression stroke, and a discharge stroke are sequentially performed. The cycle is repeated with the suction stroke, compression stroke, and discharge stroke as one cycle. Here, focusing on the compression chamber 5 indicated by dot-shaped hatching in FIG. 4, each stroke will be described. Here, in FIG. 4, the discharge port valve 7 and the slide groove 1a are not shown.
　図４（ａ）は、吸込行程における圧縮室５の状態を示している。スクリューロータ３がモータ２により駆動して、実線矢印の方向に回転する。スクリューロータ３が回転すると、図４（ｂ）に示すように圧縮室５の容積が縮小していく。 FIG. 4A shows the state of the compression chamber 5 in the suction stroke. The screw rotor 3 is driven by the motor 2 and rotates in the direction of the solid arrow. When the screw rotor 3 rotates, the volume of the compression chamber 5 decreases as shown in FIG.
　引き続き、スクリューロータ３が回転すると、図４（ｃ）に示すように、圧縮室５が吐出流路１１を介して、外部と連通する。これにより、圧縮室５内で圧縮された高圧の冷媒ガスが、吐出流路１１から外部へ吐出される。そして、再び、スクリューロータ３の背面で同様の圧縮が行われる。 When the screw rotor 3 continues to rotate, the compression chamber 5 communicates with the outside through the discharge flow path 11 as shown in FIG. Thereby, the high-pressure refrigerant gas compressed in the compression chamber 5 is discharged from the discharge passage 11 to the outside. Then, the same compression is performed again on the back surface of the screw rotor 3.
　図５は、本発明の実施の形態１におけるスクリュー圧縮機１０２の吐出ポート弁７の位置制御に係るフローチャートを示す図である。図５に基づいて、制御装置１１０が行う吐出ポート弁７の位置制御について説明する。ここで、演算装置１０７は、圧力センサー１０８が検出した圧力および温度センサー１０９が検出した温度に基づいて、冷媒ガス過熱温度を演算する。 FIG. 5 is a diagram showing a flowchart relating to the position control of the discharge port valve 7 of the screw compressor 102 according to Embodiment 1 of the present invention. The position control of the discharge port valve 7 performed by the control device 110 will be described based on FIG. Here, the arithmetic unit 107 calculates the refrigerant gas overheating temperature based on the pressure detected by the pressure sensor 108 and the temperature detected by the temperature sensor 109.
　制御装置１１０は、演算装置１０７により演算された冷媒ガス過熱温度が、あらかじめ設定された目標冷媒ガス過熱温度Ａよりも低いかどうかを判定する（ステップＳ１）。制御装置１１０は、演算された冷媒ガス過熱温度が目標冷媒ガス過熱温度Ａ以上であると判定すると、図２に示すように、冷凍サイクル装置１００の運転状態に応じた任意の位置に吐出口１０が位置するように、吐出ポート弁７を移動させる（ステップＳ２）。たとえば、スクリュー圧縮機１０２の運転効率が最も高くなる位置へ移動させる。 The control device 110 determines whether or not the refrigerant gas superheat temperature calculated by the arithmetic device 107 is lower than a preset target refrigerant gas superheat temperature A (step S1). When the controller 110 determines that the calculated refrigerant gas superheat temperature is equal to or higher than the target refrigerant gas superheat temperature A, the discharge port 10 is placed at an arbitrary position according to the operating state of the refrigeration cycle apparatus 100 as shown in FIG. The discharge port valve 7 is moved so that is positioned (step S2). For example, the screw compressor 102 is moved to a position where the operating efficiency is highest.
　一方、ステップＳ１において、制御装置１１０は、演算された冷媒ガス過熱温度が目標冷媒ガス過熱温度Ａよりも低いと判定すると、図３に示すように、吐出口１０の位置が、最も低い内部容積比となる吸込側の位置となるように、吐出ポート弁７を移動させる（ステップＳ３）。 On the other hand, when the controller 110 determines in step S1 that the calculated refrigerant gas superheat temperature is lower than the target refrigerant gas superheat temperature A, the position of the discharge port 10 is the lowest internal volume as shown in FIG. The discharge port valve 7 is moved so as to reach the suction side position that is the ratio (step S3).
　ステップＳ３において、吐出ポート弁７が最も低い内部容積比となる位置にある場合に、制御装置１１０は、冷媒ガス過熱温度が、あらかじめ設定された目標冷媒ガス過熱温度Ｂよりも低いかどうかを判定する（ステップＳ４）。制御装置１１０は、冷媒ガス過熱温度が目標冷媒ガス過熱温度Ｂよりも低いと判定すると、ステップＳ３に戻って、最も低い内部容積比となる吸込側の位置に吐出ポート弁７を継続して位置させる。ここで、目標冷媒ガス過熱温度Ａ＜目標冷媒ガス過熱温度Ｂである。 In step S3, when the discharge port valve 7 is located at the lowest internal volume ratio, the control device 110 determines whether or not the refrigerant gas superheat temperature is lower than the preset target refrigerant gas superheat temperature B. (Step S4). When the control device 110 determines that the refrigerant gas superheat temperature is lower than the target refrigerant gas superheat temperature B, the control device 110 returns to step S3 and continues to position the discharge port valve 7 at the suction side position where the lowest internal volume ratio is obtained. Let Here, the target refrigerant gas superheat temperature A <the target refrigerant gas superheat temperature B.
　一方、ステップＳ４において、制御装置１１０は、冷媒ガス過熱温度が目標冷媒ガス過熱温度Ｂ以上であると判定すると、ステップＳ２に遷移して、冷凍サイクル装置１００の運転状態に応じた任意の位置に吐出口１０が位置するように、吐出ポート弁７を移動させる。 On the other hand, when the control device 110 determines in step S4 that the refrigerant gas superheat temperature is equal to or higher than the target refrigerant gas superheat temperature B, the control device 110 transitions to step S2 and takes an arbitrary position according to the operating state of the refrigeration cycle apparatus 100. The discharge port valve 7 is moved so that the discharge port 10 is located.
　以上のように、実施の形態１の冷凍サイクル装置１００によれば、スクリュー圧縮機１０２が、圧縮室５からの冷媒ガスの吐出タイミングを調整する吐出ポート弁７を有し、制御装置１１０が、冷媒ガス過熱温度が目標冷媒ガス過熱温度よりも低いと判定すると、吐出ポート弁７を最も低い内部容積比となる吸込側に移動させて、圧縮室５内での圧縮行程における圧力上昇が小さくなるようにしたので、スクリュー圧縮機１０２に冷媒液戻りがあっても、圧縮室５内での液圧縮によるゲートロータ６などの破損を抑制することができる。このため、信頼性の高いスクリュー圧縮機１０２および冷凍サイクル装置１００を得ることができる。また、スクリュー圧縮機１０２の冷媒吸入側に配管接続され、冷媒液をためるアキュムレータが不要または小型のアキュムレータで構成することができる。 As described above, according to the refrigeration cycle apparatus 100 of the first embodiment, the screw compressor 102 includes the discharge port valve 7 that adjusts the discharge timing of the refrigerant gas from the compression chamber 5, and the control device 110 includes: If it is determined that the refrigerant gas superheat temperature is lower than the target refrigerant gas superheat temperature, the discharge port valve 7 is moved to the suction side that has the lowest internal volume ratio, and the pressure increase in the compression stroke in the compression chamber 5 is reduced. Since it did in this way, even if refrigerant liquid returns in the screw compressor 102, damage to the gate rotor 6 etc. by the liquid compression in the compression chamber 5 can be suppressed. For this reason, the highly reliable screw compressor 102 and the refrigeration cycle apparatus 100 can be obtained. In addition, an accumulator that is connected to the refrigerant suction side of the screw compressor 102 and accumulates the refrigerant liquid is unnecessary or can be configured as a small accumulator.
実施の形態２．
　前述した実施の形態１では、スクリュー圧縮機１０２がシングルスクリュー圧縮機であるものとして説明したが、これに限定するものではない。たとえば、２つのスクリューロータの溝部を噛み合わせて圧縮室を形成するツインスクリュー圧縮機においても、本発明を適用することができる。また、ゲートロータ６が１つ配置されたモノゲートロータ方式のスクリュー圧縮機においても、本発明を適用することができる。 Embodiment 2. FIG.
In the first embodiment described above, the screw compressor 102 has been described as a single screw compressor. However, the present invention is not limited to this. For example, the present invention can also be applied to a twin screw compressor in which a compression chamber is formed by meshing grooves of two screw rotors. The present invention can also be applied to a mono-gate rotor type screw compressor in which one gate rotor 6 is arranged.
　また、前述した実施の形態１では、圧力センサー１０８および温度センサー１０９を蒸発器１０６の出口に設けたが、蒸発器１０６の出口から、冷媒がスクリュー圧縮機１０２の圧縮室５内へ吸入されるまでの間であればどこへ設けてもよい。 In the first embodiment described above, the pressure sensor 108 and the temperature sensor 109 are provided at the outlet of the evaporator 106, but the refrigerant is sucked into the compression chamber 5 of the screw compressor 102 from the outlet of the evaporator 106. It may be provided anywhere between.
　また、上記の実施の形態１において、圧力センサー１０８および温度センサー１０９が検出した圧力と温度とに基づいて、圧力における飽和温度と、温度との差である冷媒ガス過熱温度を演算した。ここで、圧力センサー１０８および温度センサー１０９の計測誤差などから、演算された冷媒ガス過熱温度が０℃以上であっても、圧縮室５内への冷媒液戻りが生じている場合がある。したがって、目標冷媒ガス過熱温度Ａを、たとえば３℃と設定しておくようにすることで、スクリュー圧縮機１０２の破損を抑制して信頼性の高いスクリュー圧縮機１０２および冷凍サイクル装置１００を得ることができる。 Further, in the first embodiment, based on the pressure and temperature detected by the pressure sensor 108 and the temperature sensor 109, the saturation temperature in the pressure and the refrigerant gas superheating temperature which is the difference between the temperatures are calculated. Here, due to measurement errors of the pressure sensor 108 and the temperature sensor 109, the refrigerant liquid may return to the compression chamber 5 even if the calculated refrigerant gas overheating temperature is 0 ° C. or higher. Therefore, by setting the target refrigerant gas superheat temperature A to, for example, 3 ° C., the screw compressor 102 and the refrigeration cycle apparatus 100 can be obtained with high reliability by suppressing damage to the screw compressor 102. Can do.
　上述の実施の形態１では、冷凍サイクル装置の例として冷凍装置について説明したが、これに限定するものではない。たとえば、空気調和装置、冷蔵装置、冷凍装置など、他の冷凍サイクル装置にも適用することができる。 In Embodiment 1 described above, the refrigeration apparatus has been described as an example of the refrigeration cycle apparatus, but the present invention is not limited to this. For example, the present invention can be applied to other refrigeration cycle apparatuses such as an air conditioner, a refrigerator, and a refrigeration apparatus.
　１　ケーシング本体、１ａ　スライド溝、２　モータ、２ａ　ステータ、２ｂ　モータロータ、３　スクリューロータ、４　スクリュー軸、５　圧縮室、５ａ　スクリュー溝、６　ゲートロータ、６ａ　歯、７　吐出ポート弁、８　連結棒、９　駆動装置、１０　吐出口、１１　吐出流路、１００　冷凍サイクル装置、１０１　インバータ装置、１０２　スクリュー圧縮機、１０４　凝縮器、１０５　膨張弁、１０６　蒸発器、１０７　演算装置、１０８　圧力センサー、１０９　温度センサー、１１０　制御装置、１１１　吐出ポート弁制御装置。 1 casing body, 1a slide groove, 2 motor, 2a stator, 2b motor rotor, 3 screw rotor, 4 screw shaft, 5 compression chamber, 5a screw groove, 6 gate rotor, 6a teeth, 7 discharge port valve, 8 connecting rod, 9 Drive device, 10 discharge port, 11 discharge flow path, 100 refrigeration cycle device, 101 inverter device, 102 screw compressor, 104 condenser, 105 expansion valve, 106 evaporator, 107 arithmetic device, 108 pressure sensor, 109 temperature sensor, 110 control device, 111 discharge port valve control device.

Claims (4)

  1. 　筒状のケーシング本体と、
    　該ケーシング本体の内筒面に収容され、複数のスクリュー溝を外周面に有す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配置されたゲートロータと、
    　前記ケーシング本体と前記スクリューロータとの間にあって、前記スクリューロータの回転軸の方向における位置に応じて、圧縮された冷媒を吐出するタイミングが変更される吐出ポート弁と、
    　吸入側を流れる前記冷媒の過熱温度により、前記吐出ポート弁を移動させる駆動装置と
    を備えるスクリュー圧縮機。     A cylindrical casing body;
    A screw rotor housed in the inner cylindrical surface of the casing body and having a plurality of screw grooves on the outer peripheral surface;
    A plurality of teeth meshed with the screw grooves, arranged on the outer periphery, and a gate rotor;
    A discharge port valve located between the casing body and the screw rotor, wherein the timing of discharging the compressed refrigerant is changed according to the position in the direction of the rotation axis of the screw rotor;
    A screw compressor comprising: a driving device that moves the discharge port valve according to an overheating temperature of the refrigerant flowing on the suction side.
  2. 　請求項１に記載のスクリュー圧縮機、凝縮器、減圧装置および蒸発器が配管接続され、冷媒の循環が行われる冷媒回路が構成され、
    　前記蒸発器から流出する前記冷媒における過熱温度により、前記スクリュー圧縮機が有する吐出ポート弁の位置を決める吐出ポート弁制御装置を備える冷凍サイクル装置。     A screw compressor, a condenser, a decompression device, and an evaporator according to claim 1 are connected by piping to constitute a refrigerant circuit in which refrigerant is circulated,
    A refrigeration cycle apparatus comprising a discharge port valve control device that determines a position of a discharge port valve included in the screw compressor based on a superheat temperature of the refrigerant flowing out of the evaporator.
  3. 　前記吐出ポート弁制御装置は、前記過熱温度が目標よりも低いと判定すると、前記冷媒を吐出するタイミングが早くなる位置に、前記吐出ポート弁を位置させるように駆動装置を制御する請求項２に記載の冷凍サイクル装置。 The discharge port valve control device controls the driving device to position the discharge port valve at a position where the timing of discharging the refrigerant is earlier when it is determined that the superheat temperature is lower than a target. The refrigeration cycle apparatus described.
  4. 　前記蒸発器の冷媒流出側における温度を検出する温度検出装置と、
    　前記蒸発器の冷媒流出側における圧力を検出する圧力検出装置と、
    　前記温度検出装置の検出に係る温度と前記圧力検出装置の検出に係る圧力とから前記過熱温度を演算する演算装置と
    をさらに備える請求項２または請求項３に記載の冷凍サイクル装置。     A temperature detection device for detecting the temperature on the refrigerant outflow side of the evaporator;
    A pressure detection device for detecting the pressure on the refrigerant outflow side of the evaporator;
    4. The refrigeration cycle apparatus according to claim 2, further comprising an arithmetic device that calculates the superheat temperature from a temperature related to detection by the temperature detection device and a pressure related to detection by the pressure detection device.
PCT/JP2016/069740 2016-07-04 2016-07-04 Screw compressor and refrigeration cycle device WO2018008052A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0439573A (en) * 1990-06-04 1992-02-10 Kobe Steel Ltd Separate type heat pump
JPH06213515A (en) * 1993-01-18 1994-08-02 Kobe Steel Ltd Refrigerant controller of screw type refrigerating machine
JP2001065480A (en) * 1999-08-26 2001-03-16 Daikin Ind Ltd Screw compressor
JP2010255595A (en) * 2009-04-28 2010-11-11 Daikin Ind Ltd Screw compressor
JP2012197734A (en) * 2011-03-22 2012-10-18 Daikin Industries Ltd Screw compressor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0439573A (en) * 1990-06-04 1992-02-10 Kobe Steel Ltd Separate type heat pump
JPH06213515A (en) * 1993-01-18 1994-08-02 Kobe Steel Ltd Refrigerant controller of screw type refrigerating machine
JP2001065480A (en) * 1999-08-26 2001-03-16 Daikin Ind Ltd Screw compressor
JP2010255595A (en) * 2009-04-28 2010-11-11 Daikin Ind Ltd Screw compressor
JP2012197734A (en) * 2011-03-22 2012-10-18 Daikin Industries Ltd Screw compressor

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