JPS6156439B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly provides a refrigeration system capable of air conditioning or air conditioning, specifically a refrigeration system that is equipped with a compressor, controls the capacity of the compressor, and performs refrigeration operation with improved cooling or heating capacity. refrigeration equipment.

Conventionally, in a refrigeration system, a rotary compressor is used as the compressor, and a cylinder having a suction port and a discharge port is provided with an injection port that opens into a pumping chamber between each of the front ports. The refrigerant circuit connected to the suction port and discharge port of the machine has two heat exchangers serving as a condenser and an evaporator, as well as a gas-liquid separator installed in the middle of these heat exchangers. A gas injection passage is connected to the gas region of the liquid separator, the passage is communicated with the injection extraction port, and the intermediate pressure gas refrigerant separated by the gas-liquid separator is supplied to the pumping chamber of the cylinder. A system for increasing the capacity of a refrigeration system by increasing the capacity of the compressor above the rated capacity by injection is known, for example, as shown in Japanese Patent Laid-Open No. 54-6162.

However, in this conventional device, the angle between the center of the injection port and the center of the blade with respect to the rotation center of the rotor is 15 to 60.
After the internal contact point of the rotor to the cylinder chamber passes through the suction port, in other words, the suction stroke is completed and the compression stroke begins, the injection exit port opens and the intermediate After the gas refrigerant at the pressure is injected and the internal pressure of the cylinder becomes higher than the injection pressure of the gas refrigerant to be injected,
The injection port is then closed.

As a result, the angle from the start to the end of injection, that is, the injection angle, is small, and the amount of injection is reduced accordingly.Furthermore, the gas refrigerant that has been injection flows back until the injection port is closed, and the amount of injection is reduced. As a result, there was a problem that the capacity could not be increased sufficiently, and the internal pressure of the cylinder chamber at the start of the compression stroke was the suction pressure, so even though intermediate pressure gas refrigerant was being injected, the energy due to injection was There was a problem in which efficiency could not be improved sufficiently.

An object of the present invention is to form an injection exit port that opens into the cylinder chamber of a compressor at a predetermined position based on the flow velocity of the intermediate pressure gas refrigerant being injected, and to shape the injection port to match the rotation locus of the rotor. Effectively utilizes the gas refrigerant that is injected by forming it into a predetermined shape based on the base.
It is possible to sufficiently increase capacity and also to sufficiently improve energy efficiency.

The structure of the present invention is such that the shape of the injection port of a compressor equipped with an injection port is set at the first position of the rotor where the internal pressure of the cylinder chamber becomes the injection pressure during the compression stroke of the rotor.
The circular arc and the internal contact point of the rotor to the cylinder chamber are
a second circular arc of a rotor position displaced rearward in the rotational direction corresponding to the time for the gas refrigerant injected from the injection exit port to reach the suction port with respect to the position where the suction port is closed after passing through the suction port; The injection port has a rectangular shape with the intersection on the discharge port side as the apex and the first and second circular arcs as the hypotenuses, and the injection exit port begins to open at the rotor position of the second circular arc and finishes closing at the rotor position of the first circular arc. This enables sufficient injection of the gas refrigerant, and also immediately increases the internal pressure of the cylinder chamber to the injection pressure at the start of the compression stroke, making it possible to operate the compressor with high energy efficiency.

Embodiments of the refrigeration system of the present invention will be described below based on the drawings.

The basic structure of the refrigeration system of the present invention is as schematically shown in FIG. 1, and includes a rotary compressor 1,
A refrigerant circuit 8 having two heat exchangers 2, 3, an expansion mechanism 4, 5 divided into two, a gas-liquid separator 6 and an accumulator 7 provided at an intermediate position between these expansion mechanisms 4, 5, and the gas-liquid separator. Extending from the gas region of vessel 6,
The compressor 1 is provided with an injection passage 9 connected to an injection exit port (to be described later), and by injecting intermediate pressure gas refrigerant from the injection passage 9 into the pumping chamber of the compressor 1, capacity is increased. It was done as expected.

In the circuit shown in FIG. 1, the refrigerant circuit 7 is equipped with a four-way switching valve 10, and by switching the switching valve 10, a cooling cycle indicated by a solid line arrow and a heating cycle indicated by a dotted line arrow are formed. , an indoor heat exchanger 2 provided on the indoor side among the heat exchangers 2 and 3;
In the cooling cycle, the evaporator is used for cooling, and in the heating cycle, the condenser is used for heating.

It goes without saying that the outdoor heat exchanger 3 provided on the outdoor side functions as a condenser in the cooling cycle and as an evaporator in the heating cycle.

Further, the expansion mechanisms 4 and 5 are constructed by connecting capillary reach tubes 4a and 5a, which act during cooling, and capillary reach tubes 4b, 5b, which act during heating, in parallel, respectively. , each of the capillary reach tubes 4a,
5a, 4b, 5b have check valves 11, 1, respectively.
2, 13, and 14 are connected in series.

Further, in the above configuration, the expansion mechanisms 4, 5
Capillary reach tubes 4a, 5a, 4 constituting
By adjusting the length of the capillary tube 4a or 5b located at the front stage of the gas-liquid separator 6 with respect to the capillary tube 5a or 4b located at the rear stage among the capillary tubes 5a and 5b, the gas-liquid separator 6 The pressure of the refrigerant in the gas-liquid separator 6 is determined, and the amount of intermediate-pressure gas generated in the gas-liquid separator 6 can be adjusted.

As shown in FIG. 2, the compressor 1 includes a closed housing 20 consisting of a cylindrical housing body 20a, a housing top 20b and a housing bottom 20c, and a rotor 21a, a drive shaft 21b, a stator 21c, etc. A motor 21 consisting of
and a cylinder block 22 to be described later,
A drive shaft 2 fixed to the rotor 21a of the motor 21
1b through the cylinder block 22,
Rotor 23 installed inside the cylinder block 22
The cylinder block 22 includes a cylinder body 24 provided with a cylinder chamber 24a in the center thereof having a circular cylinder wall concentric with the axis of the drive shaft 21b, and the cylinder chamber 24a. It consists of a front head 25 and a rear head 26 having a closed plane, and the rotor 23, which rotates eccentrically with respect to the axis of the drive shaft 21b, is housed in the cylinder chamber 24a.

The compressor 1 shown in FIGS. 2 to 4 is a stationary blade rotary compressor, and the rotor 23 includes a cam 23a having a circular outer circumferential surface extending integrally from the drive shaft 21b; and a roller 23b that fits around the outer periphery of the cam 23a, and the axial center of the cam 23a is aligned with the axial center of the drive shaft 21b, in other words, the cylinder chamber 24a.
The roller 2 is eccentric to the center of the roller 2.
3b is made approximately equal to the height of the cylinder chamber 24a, in other words, the length between the planes of the respective heads 25 and 26, and its outer peripheral surface is brought into contact with the cylinder wall, and by the drive of the drive shaft 21b. The internal contact point _O1 of the roller 23b to the cylinder wall is
It has a structure that moves in the circumferential direction along the cylinder wall.

A blade 27 having a cylinder surface that is in close contact with the outer circumferential surface of the roller 23b is attached to the cylinder body 24, and openings are opened into the cylinder chamber 24a at positions close to both sides of the blade 27. A suction port 28 and a discharge port 29 are provided, and each of these ports 28, 29
An injection exit port 30 is provided at an intermediate position, which will be described later. , the roller 23b is provided between the suction port 28 and the discharge port 29.
A pumping chamber 31 is defined by an internal contact point O ₁ of the blade 27 and a contact point O ₂ of the blade 27 with the roller 23b. Further, the blade 27 has a width equal to the axial length of the roller 23b, and is slidably supported in a guide groove formed in the cylinder body 24 as shown in FIG. , the cylinder body 2
A pair of blade springs 32, one end of which is supported by a pair of blade springs 32, urge the blades 27 to protrude into the cylinder chamber 24a, so that the sealing surface of the blade 27 is always in contact with the outer peripheral surface of the roller 23b. are doing.

Further, the suction port 28 is provided horizontally on one side of the cylinder body 24, penetrating the cylinder wall, and the discharge port 29 is provided horizontally through the cylinder wall.
is provided in the front head 25 vertically through the plane, and at the opening of the discharge port 29 to the sealed housing 20,
A discharge valve 33 is provided with one end supported on the front head 25.

Further, the suction port 28 is connected to connecting pipes 34, 3.
5 are connected via a joint pipe 36,
A suction pipe 8a extending from the low-pressure side of the refrigerant circuit 8, that is, the outlet side of the accumulator 7, is connected to the connection pipe 35, and
9 is connected to the housing 2 via the discharge valve 33.
The gas refrigerant discharged from the discharge port 29 is opened to the housing top 20b.
The refrigerant is discharged through the discharge pipe 8b of the refrigerant circuit 8, which is connected to the refrigerant circuit 8.

In FIG. 2, 37 is a bracket for fixing the compressor 1, 38 is a terminal for feeding power to the stator 21c of the motor 21, 39 is a terminal guard, 40 is a terminal cover, and 41 is a bracket for fixing the motor 21. A balance weight 42 is fixed to the rotor 21a of the rotor 21a, and a magnet 42 is attached to the housing bottom 20c to remove iron powder and the like mixed into the lubricating oil filled in the bottom of the housing 20. Further, 43 is an oil pump attached to the lower end of the drive shaft 21b, and an oil passage 4 provided in the center of the drive shaft 21b supplies the lubricating oil.
It is discharged at 4. Further, the oil passage 44 includes a supply passage 44a for supplying the lubricating oil to the oil chamber 23c formed above and below the cam 23a constituting the rotor 23, and a supply passage 44a located above and below the cam 23a,
the front head 25 and the rear head 26;
A supply path 44b for supplying the lubricating oil is provided between the drive shaft 21b and the drive shaft 21b.

A muffler 45 covers the upper part of the front head 25 and is used to reduce noise caused by refrigerant discharged from the discharge port 29.

Next, the injection port 30 of the compressor 1 in the refrigeration system configured as above will be explained.

The injection extension port 30 is mainly formed in the rear head 26 so as to open in a direction perpendicular to the cylinder chamber 24a, and is connected to the cylinder chamber 24a through communication passages 50 and 51 formed in the rear head 26 and the cylinder body 24. It communicates with the injection passage 9.

The connection between the communication passages 50 and 51 and the injection passage 9 is achieved by attaching a connecting pipe 52 that passes through the housing body 20a to the opening of the communicating passage 50 that opens to the cylinder body 24, and connecting the connecting pipe 52 with the injection passage 9. This is done by connecting the injection passage 9 through the joint pipe 53.

The position and shape of the injection port 30 formed as described above will now be described.

In the compressor 1, discharge is performed once for each rotation of the rotor 23. Looking at one pumping chamber 31, as shown in FIGS. 5 to 8, the rotor 23
It is designed to be discharged in two rotations.

That is, as shown in FIG. 5, the angular position where the internal contact point _O1 of the rotor 23 with the cylinder wall is located at the contact point _O2 of the blade 27 with the rotor 23 is defined as the base point 0.
2, the volume of the pumping chamber 31 is zero at this base position, and when the internal contact point O ₁ enters the opening position of the suction port 28 from this base position, the volume of the pumping chamber 31 is zero from this base position.
The volume of the gas refrigerant increases and gas refrigerant is sucked in from the suction port 28, and the rotor 23 rotates 380 degrees from the base position as shown in _FIG . However, when the suction port 28 is closed, suction ends. At this time, the pumping chamber 31 has a maximum volume. Thereafter, the volume of the pumping chamber 31 is reduced by the rotation of the rotor 23 to compress the sucked gas refrigerant, and the discharge valve 33 opens at a position where the rotor 23 has rotated, for example, 570 degrees with respect to the base position. When the discharge of the compressed high-pressure gas refrigerant is started and the internal contact point _O1 returns to the position shown in FIG. 5, that is, the rotor 23 moves from the base position.
Dispensing ends when it rotates 720 degrees.

In the compressor 1 that operates as described above, the injection port 30 is opened and closed by the rotor 23 due to eccentric rotation of the rotor 23, and the injection port 30 is formed at the fourth position. As shown in the figure, in the compression stroke, the discharge valve 33 is located before the opening angular position and the pumping chamber 3
a first circular arc A at a rotor position where the internal pressure in the rotor 1 is equal to the injection extraction pressure (this rotor position is not limited to a position where the internal pressure is equal to the injection extraction pressure, but also includes a position where the pressure is somewhat lower than the injection extraction pressure); Rearward in the rotational direction corresponding to the time for the gas refrigerant injected from the injection exit port 30 to reach the suction port 28 with respect to the position where the internal contact O ₁ passes through the suction port 28 and the port 28 is closed. The injection port 30 is set at the intersection K on the discharge port side with the second circular arc B of the rotor position displaced to
The injection port 30 starts opening at the rotor position of the second arc B, and opens at the rotor position of the first arc A. It is completed as if it were to close at a certain position.

That is, in the suction stroke, the rotor position (FIG. 6) is just before the injection exit port 30 begins to open due to the rotor 23, and the internal contact point _O1 passes through the suction port 28 due to the rotation of the rotor 23. Rotor position with port 28 closed (Figure 7)
The angle with respect to the rotation center O of the rotor 23 is defined as a return angle θ, and when the rotor position (FIG. 7) where the internal contact point O ₁ closes the suction port 28 and the rotation of the rotor 23, the injection exit port 3
The angle between the rotor position where 0 is closed (Fig. 8) and the rotation center O is defined as the injection angle α,
And, when Pi is the injection pressure, Ps is the suction pressure, and the radius of the rotor 23 is R, As such, the injection exit port 30
, and at this set position, an injection exit port 30 is formed which has a rectangular shape with the intersection point K as the apex and the first and second arcs A and B as the hypotenuses, as described above. That's what I do.

In the above equation, C is the flow coefficient, g is the acceleration of gravity, and γ is the specific weight of the gas refrigerant. The denominator is the time t ₁ , and the denominator is the rotor 23
is the time t ₂ for rotating the return angle θ.
In addition, in the above formula, t ₁ /t ₂ =1 is preferable, but t ₁
/t ₂ <1 (however, t ₁ /t ₂ ≈1).

Further, in the above-described configuration, the rotor 23 is
It is formed by a cam 23a and a roller 23b, and an oil chamber 23c is located between the cam 23a and the roller 23b, and high-pressure lubricating oil is supplied thereto.
is preferably located at a position radially outward from an imaginary circle drawn with the drive shaft 21b as the center and a radius having a dimension extending to the inner surface of the roller 23b on a line connecting the center to the inner contact point _O1 , and ,
The opening area of the injection port 30 is:
It is usually about 2.5 mm ² , and the injection pressure Pi is set in relation to the opening area of the port 30, but it is usually 7 to 10 kg/
It is set as cm ² .

By the way, the opening area of the injection port 30 is 2.5mm ² and the injection pressure Pi is 8Kg/cm ²
In this case, the return angle θ is approximately 50 degrees, and the injection angle α is approximately 130 degrees. The injection port 30 is opened and injection is performed.

As described above, the injection port 30
is open to the pumping chamber 31 when the rotor 23 is within the range of the return angle θ and the injection angle α, and
In the intermediate-pressure gas refrigerant, injection starts at the starting point of the return angle θ in the suction stroke, and ends at the ending point of the injection exit angle α.

Therefore, when the rotor 23 is at the return angle θ, both the suction port 28 and the intermediate pressure port 51 are opened in the pumping chamber 31, so that the injected gas refrigerant flows into the suction port. However, the return angle θ is set based on the time the gas refrigerant injected from the injection exit port 30 reaches the suction port 28. The suction port 28 is closed before it flows out.

Moreover, since the port 30 has a predetermined shape, that is, a rectangular shape with the discharge port side intersection K of the first circular arc A and the second circular arc B as the apex and both circular arcs A and B as the hypotenuse as described above, the port 30 has a predetermined shape. Compared to a case where the port 30 is circular, the responsiveness of the opening/closing operation of the port 30 to the rotation of the rotor 23 is extremely good. Since the port 30 is fully opened immediately, the gas refrigerant is supplied to the pumping chamber 31 very efficiently.

Therefore, all of the gas refrigerant injected at the return angle θ can be effectively used to increase the capacity, and the internal pressure of the chamber 31 at the end of the suction stroke can be brought to the injection pressure Pi.

Further, when the rotor 23 passes through the return angle θ, the suction stroke ends, and the intake stroke enters the injection angle α and shifts to the compression stroke. This injection angle α
In this case, only the injection port 30 opens into the pumping chamber 31, and the injection port 30 is closed at a rotor position where the internal pressure of the chamber 31 is approximately equal to the injection pressure. Therefore, all the gas refrigerant that has been injected into the injection exit port 30 can be effectively used without flowing back into the injection exit port 30, and the return angle θ
The total amount of gas refrigerant that is injected in the pumping chamber 31 is added to the gas amount accommodated in the pumping chamber 31, and the injection efficiency can be improved to 99.8%, and the capacity of the compressor 1 can be increased. This makes it possible to increase performance by 19-27%.

Moreover, since the internal pressure of the chamber 1 at the start of the compression stroke can be made equal to the injection pressure Pi, energy efficiency can also be improved and highly efficient compression operation can be achieved.

Next, the fact that capacity is increased by injection of intermediate pressure gas will be explained with reference to the Mollier diagram shown in FIG.

In FIG. 9, ~ indicates the refrigeration cycle, indicates the high-pressure gas refrigerant discharged from the discharge port 29 of the compressor 1, indicates the high-pressure liquid refrigerant at the outlet side of the heat exchanger 2 or 3 serving as the condenser, and indicates the previous stage side. The liquid-gas mixed refrigerant that has been reduced to an intermediate pressure by the expansion mechanism 4 or 5 is the intermediate-pressure liquid refrigerant that has been separated by the gas-liquid separator 6, and is the liquid gas that has been reduced to a low pressure by the downstream expansion mechanism 5 or 4. Mixed refrigerant refers to the state of low-pressure gas refrigerant that is sucked in from the suction port 28 of the compressor 1 on the outlet side of the heat exchanger 3 or 2 serving as the evaporator, or is separated by the gas-liquid separator 6. This shows an intermediate pressure gas refrigerant.

Therefore, at the time of injection, the intermediate pressure gas refrigerant separated by the gas-liquid separator 6 is injection-extracted into the pumping chamber 31. When the circulation amount of refrigerant returning to the suction port 28 of the compressor 1 through the side expansion mechanism 5 or 4 and the heat exchanger 3 or 2 serving as an evaporator is G, the discharge port 2 of the compressor 1
The discharge amount of the high pressure gas refrigerant discharged from G
+g, and the discharge amount increases by the injection amount g.

Therefore, during heating, the amount of refrigerant flowing through the indoor heat exchanger 2, which has a condensing effect, increases, increasing the heating capacity, and during cooling,
The intermediate-pressure liquid refrigerant separated by the gas-liquid separator 6 is on the saturated liquid line as shown in the Mollier diagram of FIG. 9, and the latent heat of vaporization increases by Δi, and the cooling capacity can also be increased.

The embodiment described above uses a stationary blade type rotary compressor, but
A rotary blade type rotary compressor may also be used.

Further, in the embodiment, the shape of the port 30 is as follows:
As shown in FIG. 4, the discharge side intersection K of the first circular arc A and the second circular arc B is the apex, and both circular arcs A and B are formed into a triangular shape with hypotenuses, but the shape connecting both ends of the hypotenuses is It may have any shape, but the point is that a predetermined amount of gas flows into the pumping chamber 31 while the rotor 23 rotates from the starting position of the return angle θ to the final position of the injection expulsion angle α during the compression stroke of the rotor 23. The shape may be such that the opening area for injection of the refrigerant can be ensured.

As described above, the present invention provides the cylinder chamber 24 of the compressor 1.
The shape of the injection exit port 30 that opens at point a is defined by the first circular arc A at the rotor position where the internal pressure of the cylinder chamber 24a becomes the injection pressure during the compression stroke of the rotor 23, and the internal contact point of the rotor 23 with the cylinder chamber 24a. However, the rotor is displaced rearward in the rotational direction corresponding to the time required for the gas refrigerant injected from the injection exit port 30 to reach the suction port 28 with respect to the position where the suction port 28 is closed after passing through the suction port 28. The injection port 30 is opened at the rotor position of the second circular arc B, and the injection port 30 is opened at the rotor position of the second circular arc B. Since the port is made to start and close at the rotor position of the first arc A, the gas refrigerant is supplied to the cylinder chamber 24a extremely efficiently compared to the case where the port is formed circularly, and moreover, the injection exit is prevented. All gas refrigerants can be used effectively, and the overall capacity of the device can be improved to a high level.

Furthermore, since the pressure inside the cylinder can be brought to the injection pressure immediately at the start of the compression stroke, energy efficiency can be improved and an energy-saving refrigeration operation can be performed.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the present invention;
2 is a longitudinal sectional view of the compressor used in the embodiment shown in FIG. 1, FIG. 3 is a sectional view taken along the line shown in FIG. Figures 5 to 8 show the suction of the compressor.
An explanatory diagram showing the compression stroke, FIG. 9 is a Mollier diagram. 1... Compressor, 2, 3... Heat exchanger, 9... Injection passage, 23... Rotor, 24a...
...Cylinder chamber, 29...Discharge port, 30...Injection port.

Claims (1)

[Claims] 1 A rotary compressor 1 equipped with an injection port 30 opening into a cylinder chamber 24a and having a rotor 23 built into the cylinder chamber 24a, and a heat exchanger connected to an intake port 28 and a discharge port 29 of the compressor 1. A refrigeration system comprising a refrigerant circuit 8 having a gas-liquid separator 6 at an intermediate position between the gas-liquid separator 6 and an injection passage 9 communicating from the gas region of the gas-liquid separator 6 to the injection exit port 30. , the shape of the injection exit port 30 is such that during the compression stroke of the rotor 23, the first circular arc A at the rotor position where the internal pressure of the cylinder chamber 24a becomes the injection pressure, and the internal contact point of the rotor 23 to the cylinder chamber 24a. , the suction port 28
The gas refrigerant that is injected from the injection exit port 30 passes through the intake port 28 and closes the intake port 28 .
It is formed into a square shape with the intersection point on the discharge port side with the second circular arc B of the rotor position displaced rearward in the rotational direction corresponding to the time to Yonport 30
A refrigeration system characterized in that the opening starts at the rotor position of the second circular arc B and ends closing at the rotor position of the first circular arc A.