JP2000230760A - Refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporator, capable of evaporating efficiently by combining a liquid filling type and a spray type. SOLUTION: An evaporator 2 is constituted of liquid flooded type tubes 13, designed exclusively to be of a liquid flooded type and arranged in the relatively lower part of a shell 11, and spray type tubes 15, specified so as to be a spray type and arranged in the relatively upper part of the shell 11, while the ratio of the number of liquid flooded flow passages A1, A2, formed of the assembly of liquid flooded tubes 13, to the number of spray type flow passage B, formed of the assembly of spray type tubes 15, is specified so as to be 2:1. Further, high-pressure refrigerant solution in the exit port of a condenser 5 is supplied to a spray 14 for spraying the refrigerant solution against the spray type tubes 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporator, a compressor and a refrigerator having the same, and more particularly to a refrigerator having a shell and tube type evaporator and a compressor for rotating a compression section such as an impeller at a high speed. For example, it is useful when applied to a turbo refrigerator.

[0002]

2. Description of the Related Art FIG. 1 is a system diagram showing an example of the configuration of a turbo refrigerator. As shown in FIG.
The refrigerant gas (e.g., organic refrigerant such as fluorocarbons) vaporized in is sucked into the suction portion 1c, and is condensed by two-stage compression (one-stage compression is of course also possible) by the impeller 4 rotating at high speed by the drive motor 3. It is configured to discharge to the vessel 5. The evaporator 2 is of a type called a full-fill type in which the refrigerant liquid is evaporated by performing heat exchange between the refrigerant liquid filled therein and cold water (brine) taken therein. is there. The condenser 5 cools the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 with cooling water flowing in the tube to condense and liquefy. Intercooler 6
Is for maintaining a constant pressure difference between the condenser 5 and the evaporator 2 and evaporating a part of the refrigerant to increase the latent heat of the evaporator 2. Therefore, the intercooler 6 is necessary when a multi-stage compressor is provided, and is not necessary for a single-stage compressor. Note that the solid line in the drawing is the refrigerant liquid pipe, and the dotted line is the refrigerant gas pipe.

(111) In such a centrifugal chiller, since the temperature of the cold water flowing in the tube of the evaporator 2 is higher than that of the refrigerant around the tube, heat is transferred from the cold water to the refrigerant. As a result, the refrigerant liquid evaporates at a temperature corresponding to the pressure inside the evaporator 2, is sucked into the compressor 1, is compressed by the first-stage impeller 4 rotating at high speed, and is cooled at a low temperature flowing from the intercooler 6. After the temperature is reduced by the refrigerant gas, it is further compressed by the second stage impeller 4 and sent to the condenser 5. The high-pressure gas in the condenser 5 is cooled by the cooling water flowing in the tube, and condenses at a temperature corresponding to the pressure in the condenser 5.

[0004] The refrigerant liquid condensed in the condenser 5 enters an intercooler 6 connected to the condenser 5 by a pipe, is decompressed to an intermediate pressure by a first-stage orifice and expanded, and a part thereof is vaporized to a refrigerant gas. . This refrigerant gas is sucked into the second stage impeller 4 of the compressor 1 via the pipe. On the other hand, the remaining refrigerant liquid whose temperature has been lowered by evaporation of the refrigerant liquid is further reduced in pressure in the second-stage orifice, enters the evaporator 2 and evaporates.

In such a refrigerator, a shell-and-tube type evaporator 2 is generally used. The shell-and-tube evaporator 2 can be further divided into a liquid-filled shell-and-tube evaporator and a spray-type shell-and-tube evaporator.

Liquid-filled shell-and-tube evaporator 2
As shown in FIG. 20, a large number of tubes 13 for circulating cold water that exchanges heat with a refrigerant are arranged horizontally in the axial direction of the shell 11 in a cylindrical container called a shell 11. In addition, the tube 13 is immersed in the refrigerant liquid 12 filled in the shell 11, and the refrigerant liquid 12 boils and evaporates by heat exchange with cold water flowing through the tube 13. Therefore, the heat transfer in this case is performed by boiling and evaporation. On the other hand, as shown in FIG. 21, the spray type shell-and-tube evaporator 2 has a shell 11 and a tube 15 similar to those of the liquid-filled type.
And a spray 14 disposed above the tube 15 in the shell 11, and dispenses the refrigerant liquid 12 stored in the liquid reservoir 17 fixed to the lower surface of the shell 11.
It is pumped up at 8 and sprayed toward a tube 15 via a spray 14. Thus, the sprayed refrigerant liquid adheres to the outer peripheral surface of the tube 15 to form a liquid film 16, and the refrigerant liquid is evaporated by exchanging heat with cold water flowing through the tube 15. Therefore, the heat transfer in this case is performed by film evaporation. That is, the liquid-filling type and the spraying type are common in the point of the shell and tube type, but their evaporation modes or heat transfer modes are different. In addition, as shown in FIG. 22, the jet pump 19 is driven by a high-pressure refrigerant liquid generated in the condenser 5 to pump up the refrigerant liquid 12 and spray the refrigerant liquid 12 toward the tube 15 via the spray 14. Yes, and has the same function in this case.

As described above, the evaporator 2 includes a liquid-filled shell-and-tube type evaporator and a spray-type shell-and-tube type evaporator. A shell-and-tube evaporator is used. This is because the spray-type shell-and-tube evaporator 2 according to the related art has a low evaporation performance, and if it is desired to secure a desired evaporation performance, the size of the evaporator must be increased. On the other hand, in the liquid-filled shell-and-tube evaporator 2, the depth of the refrigerant liquid 12 from the liquid surface is affected by the liquid pressure of the refrigerant liquid 12 (the depth from the liquid surface of the refrigerant liquid 12). As the depth increases, the boiling pressure of the refrigerant liquid 12 increases by the amount of the liquid column, and the refrigerant liquid 12 is less likely to evaporate. That is, since the boiling / evaporation is not uniform depending on the position of the tube 13, it is not suitable for an application in which precise temperature control of cold water is performed.

On the other hand, the spray-type shell-and-tube evaporator 2 performs heat transfer by film evaporation, and uniform evaporation is ensured in each tube 15. Therefore, precise temperature control of the cold water can be performed.
For this reason, the spray-type shell-and-tube evaporator 2 is used as an application that requires precise control of the temperature of cold water, for example, as a supercooler for producing supercooled water in a dynamic ice heat storage system.

(222) The drive motor 3 of the compressor 1 in such a centrifugal chiller generates heat with its driving, and thus needs to be cooled. In the refrigerator shown in FIG. 19, the stator 3a and the rotor 3b of the drive motor 3 are cooled by the refrigerant liquid on the outlet side of the condenser 5. For this reason,
The refrigerant liquid at the outlet side of the condenser 5 is supplied to the drive motor 3 via the pipe 21, and the gaseous refrigerant gas after cooling is discharged to the evaporator 2 via the pipe 22. ing. That is, the condenser 5 side of the pipe 21 is higher in pressure than the drive motor 3 side, and the drive motor 3 side of the pipe 22 is higher in pressure than the evaporator 2 side. The refrigerant liquid is supplied to the inside of the drive motor 3 via 21, and the cooled refrigerant is discharged to the evaporator 2 via the pipe 22.

The cooling structure of the driving motor 3 according to the prior art will be described in more detail with reference to FIG. FIG. 23 is an explanatory diagram extracting and showing a part of the driving motor 3. As shown in the figure, a vertical hole 3d is provided at the center of the stator core 3c from above to the center along the radial direction.
Refrigerant liquid supplied from the condenser 5 reaches the gap between the inner peripheral surface of the stator core 3c and the outer peripheral surface of the rotor core 3e through the hole 3d, and extends along the gap in the axial direction (see FIG. It is configured to flow in the direction of arrow A). Further, the refrigerant liquid is also supplied to the outer peripheral surface of the stator core 3c, flows along the outer peripheral surface in the axial direction (arrows B and C in the figure), flows through the gap, and from the end thereof. After being discharged, the refrigerant is discharged to the evaporator 2. That is,
A liquid refrigerant is supplied to a gap between the inner peripheral surface of the stator core 3c and the outer peripheral surface of the rotor core 3e. At this time, a part of the refrigerant liquid is vaporized and evaporated to form a refrigerant gas. The heat generated by the stator 3a and the rotor 3b is also effectively absorbed and cooled by the heat of vaporization accompanying the heat treatment.

(333) Such a centrifugal chiller is a rotating body, has a bearing, and needs to be lubricated. This lubricating oil system piping is shown by a dashed line in FIG. The lubrication points in this case are the bearings 3f, 3g that support the rotating shaft of the drive motor 3,
Bearings 8a and 8b for supporting the rotating shaft of the impeller 4 of the compressor 1
And the speed increasing gear 9 and the like. Each of these parts includes a compressor 1
The lubricating oil is supplied via an oil cooler by the driving of an oil pump 7 built in an oil tank 1b in the casing 1a. As the bearings 3f, 3g, 8a, 8b in this case, a hydrostatic bearing 31 as shown in FIG. 24 is usually used. This hydrostatic bearing 31 has a central hole 31 as shown by an arrow in the figure.
The rotary shaft 3 for press-fitting the lubricating oil in the radial direction through the
2 is formed so that an oil film is formed between the rotating shaft 32 by injecting the fluid onto the outer peripheral surface of the rotating shaft 32, flowing along both sides in the axial direction of the rotating shaft 32, and flowing out from the outlet 31b. Rotating shaft 32 through oil film
To support.

(444) As the lubricating oil in this case, a lubricating oil which can be generally dissolved in a refrigerant is used. This is to prevent the lubricating oil from accumulating in a specific place other than near the liquid surface of the evaporator 2 and to enable circulation with the refrigerant. The lubricating oil comes into contact with the refrigerant in the casing 1a. The lubricating oil is mixed into the refrigerant, and the refrigerant in this state reaches the evaporator 2 via the condenser 5. Therefore, in the evaporator 2, the refrigerant evaporates to gas and the compressor 1
However, since the lubricating oil does not evaporate, the lubricating oil remains in the evaporator 2 and has a specific gravity smaller than that of the refrigerant. Therefore, a layer having a high lubricating oil density is formed on the uppermost layer of the refrigerant liquid in the evaporator 2. You.

However, in a refrigerator having a liquid-filled evaporator 2, when a certain amount or more of oil dissolves in the refrigerant, the heat transfer characteristics of the refrigerant decrease, and the pressure in the evaporator 2 abnormally decreases. This causes an increase in the power of the compressor 1. For this purpose, an oil recovery device is provided.

FIG. 25 is an explanatory view conceptually showing this type of oil recovery apparatus according to the prior art. As shown in the figure, the openings 2a, 2b, 2c open toward the inside of the evaporator 2 so as to collect a mixed liquid of lubricating oil and refrigerant liquid, and are also provided in the height direction of the evaporator 2 as appropriate. A plurality (three in the figure) is attached to the shell 11 or the tube sheet 2d.
Each opening 2a, 2b, 2c is provided with a valve 41a, 41b, 41
c, communicating with the suction port of the ejector 43 via the dryer 42; Similarly, an opening that opens into the condenser 5 communicates with the drive fluid port of the ejector 43 via the valve 45. The discharge port of the ejector 43 communicates with the oil tank 1b via the valve 44.

The ejector 43 supplies the transfer power in this oil recovery device. The ejector 43 utilizes the fact that the refrigerant gas pressure at the inlet of the condenser 5 is sufficiently higher than the pressures of the other parts (evaporator 2 and oil tank 1b), and the oil level of the lubricating oil in the oil tank 1b is predetermined. At the time when the oil level is lowered to the lower limit position to start collecting the lubricating oil, and stop when the oil level is restored to the predetermined position. More specifically, the valve 44 is fully opened during operation. Thereafter, the valve 45 is opened to supply the refrigerant gas as the driving fluid to the ejector 43. As a result, a gas flow toward the oil tank 1b is formed by the function of the ejector 43. When any one of the valves 41a, 41b, and 41c is opened in this state, the mixed liquid of the refrigerant and the lubricating oil is sucked by the ejector 43, and then the mixed liquid is carried on the gas flow to the oil tank 1b.

Here, three openings 2a to 2c are provided because the liquid level of the refrigerant liquid in the evaporator 2 varies depending on the load state and the operating state of the turbo refrigerator.
That is, when the load is large, the liquid level of the refrigerant liquid rises,
It goes down when the load is low. When the pressure of the condenser 5 is high, the liquid level rises, and when it is low, the liquid level falls. For this reason, it is necessary to correspond to a plurality of liquid levels such as upper, middle and lower.

On the other hand, as shown in FIG. 19, lubricating oil also adheres to the casing 1a around the suction portion 1c of the compressor 1, but the lubricating oil is collected in the oil tank 1b. The oil tanks 1b communicate with each other via a pressure equalizing pipe 46. This is because the oil tank 1b and the suction unit 1c having the lowest pressure in the refrigerator have the same pressure, and the lubricating oil present in the suction unit 1c is always collected in the oil tank 1b due to the difference in position head.

[0018]

(111) As described above, the shell-and-tube type evaporator 2 according to the prior art is used.
As shown in FIG. 20, a liquid-filled shell-and-tube evaporator 2 is usually used for large refrigerators, except for special applications. In such a liquid-filled shell-and-tube evaporator 2, all tubes 13 are filled with the refrigerant liquid 12 at the maximum load when the liquid level is highest even if the liquid level of the refrigerant liquid 12 rises due to bubbles during evaporation.
The refrigerant liquid 12 is filled so as to be immersed. Therefore, at the time of partial load, the liquid level of the refrigerant liquid 12 is lowered, and some of the upper tube 13 which is not immersed in the refrigerant liquid 12 and does not contribute to the boiling and evaporation of the refrigerant liquid 12 appears. Furthermore, even at the time of maximum load, the upper tube 13 is immersed in the refrigerant liquid 12 having a high void ratio (the ratio of gas is high) by the refrigerant gas from the lower tube 13, so that the tube is specialized for the liquid-filled type. No. 13 cannot make full use of its characteristics. For this reason, the assembly of the tubes 13 includes an ineffective portion that does not contribute to heat transfer, which causes a problem of lowering the overall heat exchange performance.

(222) As shown in FIG. 23, in the compressor 1 of the refrigerator according to the prior art, since the drive motor 3 is cooled by the refrigerant liquid, the heat capacity is large and the refrigerant liquid evaporates. Since heat can also be used, good cooling performance can be obtained.
The highly viscous refrigerant liquid flows into the gap between the inner peripheral surface of the rotor c and the outer peripheral surface of the rotor core 3e, which becomes a resistance when the rotor 3b rotates and increases the power of the drive motor 3. It becomes a factor. Such an increase in power becomes more remarkable as the rotation speed of the drive motor 3 increases.

(333) As described above, in the refrigerator according to the prior art, in order to prevent the lubricating oil leaking into the refrigerant from being stored in a place where it cannot be recovered, this lubricating oil is applied to the refrigerant to a certain extent. Those having compatibility are used. In this case, since the viscosity of the refrigerant liquid is lower than that of the lubricating oil, when the ratio of the refrigerant dissolved in the lubricating oil increases, a problem arises in that the bearing load capacity of the lubricating oil decreases. Also,
Since the lubricating oil leaks into the refrigerant, a large amount of time is required for periodic collection, replenishment, replacement, and other maintenance.

The above-mentioned problems associated with the use of a lubricating oil can be solved if the refrigerant itself can be used in place of the lubricating oil. However, if the refrigerant liquid is used, the bearing load capacity is low and the bearing size is large. In addition to the shape, the hydrostatic bearing 3
In some cases, the refrigerant liquid supplied to the inside 1 may evaporate before reaching the outlet 31b due to the heat generated in the portion of the rotating shaft 32 therein. In such a case, the bearing load capacity is extremely reduced. There is a problem. To solve this problem, a method of employing a refrigerant gas from the beginning is also conceivable. However, in the case of the refrigerant gas, the bearing load capacity is further low, and therefore, this problem cannot be solved by the idea of an existing hydrostatic bearing.

(444) The lubricating oil that has flowed out to the refrigerant system in the prior art as described above is basically collected in the evaporator 2 and the lubricating oil remaining in the evaporator 2 is ejected by the ejector 43.
And is collected by returning to the oil tank 1b. At this time, in the ejector 43, the gas flow from the condenser 5 toward the oil tank 1b functions as a driving fluid for transporting the lubricating oil in the evaporator 2. Therefore, the ability of the ejector 43 to recover the lubricating oil is determined by the pressure difference between the condenser 5 and the oil tank 1b, and no further recovery can be performed.

On the other hand, in the suction section 1c of the compressor 1, lubricating oil contained as mist in the refrigerant gas scatters and adheres to the surrounding casing 1a and the like, descends by its own weight, and accumulates in the lower part. Although the lubricating oil scattered and adheres to the surroundings lubricates the drive link of the vane of the suction portion 1c, the phenomenon is actively used, but lubricating oil more than the amount required for lubrication adheres. In many cases. Further, inside the oil tank 1b, the lubricating oil also exists as a mist, but the mist-like lubricating oil flows out to the suction part 1c side through the equalizing pipe 46 and is liquefied. It adheres around the suction part 1c. The liquefied lubricating oil adhering to the periphery of the suction part 1c in such a manner is stored in a place where it cannot be recovered in some cases.

Therefore, in order to accurately recover the lubricating oil that has flowed into the refrigerant system, it is necessary to effectively recover the lubricating oil that adheres to the vicinity of the suction section 1c of the compressor 1.

The present invention has the following object in view of the above prior art. (111) To provide an evaporator capable of efficiently performing evaporation by combining a liquid filling type and a spray type, and a refrigerator having the same. (222) An object of the present invention is to provide a compressor drive motor having improved cooling performance of a compressor drive motor and low rotation loss, and a refrigerator having the same. (333) An object of the present invention is to provide a compact compressor which can ensure good bearing performance without using a liquid bearing, and a refrigerator having the same. (444) To provide a compressor and a refrigerator capable of effectively collecting lubricating oil adhering around a suction portion of the compressor, and an operation method thereof.

[0026]

The structure of the present invention that achieves the above object has the following features. 1) In a shell-and-tube type evaporator, a liquid-filled tube specialized for a liquid-filled type is disposed at a relatively lower portion in a shell so as to boil and evaporate the refrigerant liquid in a state of being immersed in the refrigerant liquid. At the same time, a spray tube specially designed for spraying is disposed at a relative upper portion in the shell so as to evaporate the refrigerant liquid attached by spraying from an upper spray, and further, an assembly of the above liquid-filled tubes The number of the flow paths included in the full-flow type flow path formed by the above and the number of the flow paths included in the spray-type flow path formed by the assembly of the spray-type tubes are the same as the number of the flow paths included in the spray-type flow path. Is smaller than or equal to the number of flow passages included in the flooded flow passage, and the liquid flowing out of the flooded flow passage or the spray flow passage is discharged by the spray flow passage or the flooded flow passage. On the road That it was configured to flow in. According to the present invention, not only can the heat flux having the optimum heat transfer rate be obtained for each flow path formed by the filled tube and the spray tube, but also one of the filled tubes at the time of partial load. Even if the part is not immersed in the refrigerant liquid, the surface of the liquid-filled tube in such a state can be wet by the refrigerant liquid flowing down the upper spray type tube, so that heat conduction due to film evaporation also occurs in this part. Done. In addition, the amount of the coolant liquid supplied to the spray is an amount sufficient to secure the wettability necessary for the heat transfer of the spray tube.

2) The evaporator according to 1), wherein the spray is configured to spray high-pressure refrigerant liquid from a condenser, an intercooler or a subcooler. Thereby, the refrigerant liquid more than the refrigerant liquid amount required in the spray type flow passage is sprayed from the spray type flow path without requiring special equipment such as a refrigerant pump in the spray type shell and tube evaporator according to the prior art. It can be sprayed into a spray tube.

3) In the evaporator described in 1) or 2) above, the liquid-filled tube is formed by a boiling heat transfer promoting tube having a large number of depressions on the surface of the tube body. As a result, the refrigerant liquid enters the depression of the boiling heat transfer promotion tube, and the refrigerant liquid thus entered condenses and exchanges heat with cold water flowing through the liquid-filled tube to evaporate, thereby increasing the heat transfer of the refrigerant liquid. It can be boil-evaporated with performance.

4) In the evaporator described in 1) or 2) above, the number of the spray type tubes is increased while optimizing the height of the fins provided on the surface of the tube body in a radial direction. Is cut off in the axial direction so that the adhering refrigerant liquid can move along the notch. As a result, the liquid film of the coolant liquid attached to the spray tube can be spread over the entire surface of the spray tube, so that the liquid film can be effectively evaporated.

5) In a compressor that compresses and discharges the sucked refrigerant gas by rotating a compression section such as an impeller by a drive motor, a stator space for occupying a stator of the drive motor, a stator and A partition member is provided between the rotor space and the rotor space including the gap between the rotors to occupy the rotor, and the two spaces are separated from each other. After cooling, the refrigerant liquid is discharged from the refrigerant liquid discharge port, and the refrigerant gas is supplied to the rotor space from the refrigerant gas supply port, and is circulated in the axial direction along the gap between the stator and the rotor to rotate. Cooling the cooling element and then discharging the refrigerant gas from the refrigerant gas outlet. According to the present invention, the stator space and the rotor space are separated by a partition member to become independent separate spaces, and the stator is cooled by a refrigerant liquid having a large heat capacity, and the rotor, particularly the inner periphery of the stator. The part facing the gap between the surfaces is cooled by a low-viscosity refrigerant gas.

6) The compressor described in 5) above is one in which the impeller of the compression section is directly connected to the rotating shaft of the drive motor. As described above, since the impeller is directly connected to the rotating shaft of the drive motor, it is necessary to rotate the drive motor at high speed. However, by cooling with a low-viscosity refrigerant gas, an increase in motor rotation loss can be suppressed. .

7) In the compressor described in 5) or 6) above, the cooling ring is fixed to the rotating shaft facing the passage of the refrigerant gas to increase the cooling capacity of the rotor. As a result, the refrigerant gas also exchanges heat with the ring, so that the rotor is also cooled by the refrigerant gas via the ring.

8) In the refrigerator having the compressor according to any one of the above 5) to 7), the inside of the stator space of the drive motor is provided from the outlet side of the condenser through the refrigerant liquid supply port of the compressor. The refrigerant liquid is supplied to the evaporator and the refrigerant liquid discharged from the refrigerant liquid outlet is supplied to the inlet side of the evaporator, while the refrigerant liquid is supplied from the outlet side of the evaporator to the rotor space of the drive motor through the refrigerant gas supply port of the compressor. The refrigerant gas is supplied and the refrigerant gas discharged from the refrigerant gas outlet is returned to the suction part of the compressor. As a result, the stator is cooled by the refrigerant liquid having a large heat capacity supplied from the condenser, and the rotor, in particular, the portion facing the gap between the inner peripheral surface of the stator and the rotor has a low viscosity supplied from the evaporator. Cooled by refrigerant gas. At this time, the refrigerant liquid is supplied into the stator space by a pressure difference between the condenser and the evaporator. The refrigerant liquid that has cooled the stator is returned to the evaporator, and the refrigerant gas that has cooled the rotor is returned to the suction section of the compressor, and functions as a refrigerant for the refrigerator.

9) In the refrigerator having the compressor described in any one of 5) to 7) above, the refrigerant liquid pumped up by the refrigerant pump from the outlet side of the evaporator is supplied through the refrigerant liquid supply port of the compressor. While supplying the refrigerant liquid into the stator space of the drive motor and supplying the refrigerant liquid discharged from the refrigerant liquid discharge port to the inlet side of the evaporator, the refrigerant liquid is driven from the outlet side of the evaporator through the refrigerant gas supply port of the compressor. The refrigerant gas is supplied to the rotor space of the electric motor. In this case, since the refrigerant liquid is pumped from the outlet side of the evaporator by the refrigerant pump, the refrigerant liquid can be reliably supplied into the stator space even when the refrigerator is started.

10) In a compressor that compresses a refrigerant gas in a compression section by rotation of a drive motor, a high-pressure refrigerant gas is supplied to a gap between a rotor core and a stator core of the drive motor, and the refrigerant gas is supplied to the gap. A static pressure bearing for working fluid is formed, and the static pressure bearing is configured to support a rotor core. According to the present invention, the rotor core of the drive motor is supported by the static pressure bearing using the same type of refrigerant gas as the refrigerant gas to be compressed by the compressor.

11) The high-temperature and high-pressure refrigerant gas compressed by the compressor driven by the drive motor is condensed by exchanging heat with the cooling water in the condenser, and the high-pressure refrigerant liquid condensed in this way is evaporated by the evaporator. In a refrigerator configured to evaporate by exchanging heat with cold water and return to the compressor as a low-pressure refrigerant gas, the rotor core of the drive motor is provided in a gap between the rotor core and the stator core. The bearing is configured to be supported by a static pressure bearing formed by supplying a high-pressure refrigerant gas. As a result, the rotor core of the drive motor is supported by the static pressure bearing using the same type of refrigerant gas as the refrigerant gas to be compressed by the compressor of the refrigerator.

12) In the refrigerator described in 11) above, the high-pressure refrigerant gas that supports the rotor core when the compressor is started uses the refrigerant gas in the pressure tank that is separately stored, while the compression gas is compressed. As the high-pressure refrigerant gas supporting the rotor core during steady operation of the machine, the refrigerant gas discharged from the compressor is used as it is, and the refrigerant gas serving as the working fluid of the static pressure bearing of the rotor core is returned to the evaporator. It was configured as follows. As a result, the rotor core is floated by the high-pressure refrigerant gas stored in the pressure tank when the compressor is started, and the rotor core of the drive motor is continued by the high-temperature and high-pressure refrigerant gas compressed by the compressor during the steady operation of the compressor. To support. In this case, the refrigerant gas functioning as the working fluid of the hydrostatic bearing is supplied to the evaporator.

13) In the refrigerator described in 11) above, the high-pressure refrigerant gas that supports the rotor core when starting the compressor uses the refrigerant gas in the pressure tank that has been separately stored, while using the refrigerant gas. The high-pressure refrigerant gas that supports the rotor core during steady-state operation of the compressor is obtained by compressing the saturated refrigerant gas of the condenser with another gas compressor, and the refrigerant gas that has functioned as the working fluid of the static pressure bearing is the condenser gas. That it is configured to return to

14) In the refrigerator described in 11) above, the high-pressure refrigerant gas that supports the rotor core at the time of starting the compressor uses refrigerant gas in a pressure tank that has been separately stored, while compressing. The high-pressure refrigerant gas that supports the rotor core during normal operation of the compressor is obtained by compressing the refrigerant gas of the evaporator with another gas compressor, and the refrigerant gas that has functioned as the working fluid of the static pressure bearing is sent to the evaporator. Configured to return.

15) In the refrigerator described in 11) above, the high-pressure refrigerant gas that supports the rotor core when starting the compressor uses the refrigerant gas in a pressure tank that is separately stored, while the compression gas is compressed. The high-pressure refrigerant gas that supports the rotor core during steady-state operation of the compressor is obtained by compressing the refrigerant gas of the evaporator with another gas compressor, and the refrigerant gas that functions as the working fluid of the static pressure bearing is sent to the condenser. Configured to return.

16) The refrigerant gas sucked into the suction part is compressed and discharged to the condenser as a high-temperature and high-pressure refrigerant gas, and the lubricating oil stored in the oil tank in the casing is driven by an oil pump to drive the bearing portion and the like. In the compressor configured to supply the lubricated portion, a jet pump is provided between the suction portion of the refrigerant gas and the oil tank, the jet pump having lubricating oil pumped by an oil pump as a drive fluid, and the jet pump is driven by the jet pump. The lubricating oil present in the suction section is collected in the oil tank.

17) The high-temperature and high-pressure refrigerant gas compressed by the compressor is condensed by exchanging heat with the cooling liquid in the condenser, and the high-pressure refrigerant liquid thus condensed is exchanged with cold water by the evaporator. It is configured to evaporate and return to the compressor as a low-pressure refrigerant gas, and in the compressor, lubricating oil stored in an oil tank in the casing is driven by an oil pump to a lubricating portion such as a bearing portion. In the refrigerating machine configured to supply, a jet pump that uses lubricating oil pumped by an oil pump as a driving fluid is provided between a suction portion of the refrigerant gas in the compressor and the oil tank, and the jet pump drives the The lubricating oil present in the suction section is collected in the oil tank.

18) The method for operating a refrigerator described in 17) above, wherein only the operation of the oil pump is continued for a certain period of time after the refrigerating operation of the refrigerator is stopped.

[0044]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(111) FIG. 1 is an explanatory view conceptually showing an evaporator according to an embodiment of the present invention. The evaporator 2 according to this embodiment is a shell-and-tube type heat exchanger similar to a conventional evaporator, but has a configuration in which a liquid-filled shell-and-tube type and a spray-type shell-and-tube type are combined. It has become. That is, the liquid filling type tube 13 specialized for the liquid filling type is disposed at a relatively lower portion in the shell 11, and the spray type tube 15 specialized for the spray type is disposed at the relative upper portion in the shell 11. It is set up. Furthermore, in this embodiment, in order to give the load condition that the heat flux is large to the spray-type flow passage B and to make the liquid-filled flow passage A a low heat-flux region, the spray-type flow passage formed by the assembly of the spray-type tubes 15 is used. Cold water flowing out of B
Fluid-filled flow passage A formed by an aggregate of fluid-filled tubes 13
It is formed so as to flow into. Such a load condition may be reversed. In this case, the structure is such that the cold water cooled in the liquid-filled flow passage A is further cooled in the spray-type flow passage B.

Here, the “full-fill type tube 13 specialized for the full-fill type” refers to the refrigerant liquid 1 immersed in the refrigerant liquid 12.
2 has good heat transfer characteristics when pool boiling, and is called a boiling heat transfer promoting tube in which a number of depressions 13b are formed in the surface of a tube body 13a as shown in FIG. 2 (a), for example. It can be suitably formed with a tube. When this boiling heat transfer promotion tube is used, the depression 13b
The refrigerant liquid 12 enters the cooling medium, and the refrigerant liquid 12 that has entered in this way intensively exchanges heat with cold water and evaporates. That is,
By limiting the evaporation site to the recess 13b, boiling and evaporation can be performed efficiently.

The “spray type tube 15 specialized for the spray type” means that the refrigerant liquid to be sprayed and adhered from the spray 14 disposed above the spray type tube 15 inside the shell 11 is film-evaporated. In this case, it has good film heat transfer characteristics. For example, as shown in FIG.
The height of the fins 15b provided on the surface of the tube body 15a so as to protrude in the radial direction is optimized and the number thereof is increased. Are configured to be able to move along the notch 15c. From the idea that the surface area of the tube should be as large as possible in order to efficiently perform the film evaporation, conventionally, for this application, a fin tube having fins projecting radially from the tube body has been used. However, for simple fin tubes, spray 1
The refrigerant liquid sprayed from 4 and adhered to the fins stays at the adhering portion due to the presence of the fins, and a portion of the fin tube that is wetted by the refrigerant liquid and a portion that is not wet are caused, thereby suppressing the overall evaporation performance to be low. Had become. The spray type tube 15 used in this embodiment is a fin 15
Since the height of the fin 15b is set optimally, that is, the height of the fin that can secure a sufficient surface area, not only the droplet of the refrigerant liquid adhering to the fin 15b spreads in the axial direction but also the notch portion 15c, the notch 15c
Can also spread the droplet in the axial direction. Thus, the liquid film formed on the spray-type tube 15 spreads over the entire surface of the spray-type tube 15, and the wetting of the spray-type tube 15, which is an essential requirement for effective film evaporation in the spray-type tube 15. Good property can be ensured.

The liquid filled tube 13 has a heat flux (Kcal / Kcal / Kcal / Kcal /
m ₂ h) is a wide region, and has a characteristic that it has a constant extra-tube heat transfer coefficient (h ₀ ) characteristic regardless of its size. That is, even when used in a region where the heat flux is low (the number of liquid-filled tubes 13 is large), the heat transfer coefficient outside the tube does not decrease, so that the characteristics can be utilized when used in a region where the heat flux is low. Can be said to be. On the other hand, the external heat transfer coefficient (h ₀ ) characteristic of the spray tube 15 has a characteristic that the heat flux (Kcal / m ₂ h) gradually increases linearly from a low region to a high region. Therefore, it is possible to set the optimal load sharing in the heat flux for each flow path (path) formed by the assembly of the liquid filling type tube 13 and the spray type tube 15, and by setting the optimal load sharing, The number of tubes included in the evaporator 2 can be reduced. By the way, in the case of the present embodiment, by using the liquid filled tube 13 in the region of the low heat flux and using the spray tube 15 in the region of the high heat flux, the whole of the conventional method is formed by the liquid filled tube 13. The overall number of tubes can be reduced as compared with a liquid evaporator.

In the evaporator 2 according to this embodiment, the liquid-filled flow path A is formed by two flow paths A1 and A2, and the spray-type flow path B is formed by one flow path. That is,
It has three full-flow type flow paths A1 and A2 and a spray type flow path B. Thus, as shown in FIG. 3, the cold water flowing from the cold water inlet 51 into the water chamber 52 passes through the spray type flow passage B, which is an assembly of the spray type tubes 15, and reaches the water chamber 53 on the opposite side. The liquid-filled flow path A2, which is an assembly of the folded liquid-filled tubes 13, reaches the water chamber 54, and then returns again to flow through the liquid-filled flow path A1, which is an assembly of the liquid-filled tubes 13. To the water chamber 55 and flows out through the cold water outlet 56.
At this time, the number of the filled tubes 13 included in the filled flow passages A1 and A2 is the same, but the number of the spray tubes 15 included in the sprayed flow passage B is equal to the filled passage A.
1 or a liquid-filled tube 13 included in the liquid-filled flow passage A2
May be less than the number of. Filled tube 1 as described above
3 is used in a region where the heat flux is small, and the spray tube 15 is used in a region where the heat flux is large.

As shown in FIG. 1, a refrigerant liquid is supplied to the spray 14 through a pipe line 61 and an expansion valve 62 which are directly connected to the outlet of the condenser 5. Therefore,
A high-pressure refrigerant liquid is supplied to the spray 14, and the refrigerant liquid is sprayed toward the spray tube 15 via the spray 14. Spray 1 at this time
Reference numeral 4 also functions as an expansion valve. More specifically, the expansion valve 62 functions as an expansion valve at a partial load, while the spray 14 mainly functions as an expansion valve at and near the rated load.

In the evaporator 2 of the present embodiment as described above,
The cold water passing through the two full-flow passages A1 and A2 exchanges heat with the refrigerant liquid 12 immersed in the full-flow passages A1 and A2 to cause the refrigerant liquid 12 to boil and evaporate. The cold water passing through the flow passage B and the film refrigerant adhered to the surface of each spray tube 15 sprayed by the spray 14 to form the spray flow passage B exchange heat to evaporate the film. That is, evaporation of the refrigerant liquid 12 due to boiling / evaporation and film evaporation occurs. Here, when the refrigerator is operated at a partial load, the refrigerant level of the evaporator 2 drops, and the upper one of the liquid-filled tubes 13 is exposed from the liquid level of the refrigerant liquid 12, However, in this case, the refrigerant liquid flowing down from above adheres to the exposed full liquid type tube 13 and the spray type tube 15
Heat exchange by film evaporation similar to that described above is performed, and the exposed portion does not become an ineffective portion that does not contribute to the heat exchange.

Further, in the evaporator 2 according to the above-described embodiment, the liquid-filled flow passage A of the liquid-filled tube 13 is used.
Since the ratio of 1, 1 to the spray-type flow passage B of the spray-type tube 15 was set to 2: 1, and the refrigerant liquid was supplied to the spray 14 from the outlet of the condenser 5 through the expansion valve 62, When the evaporator 2 functions as a spray-type evaporator and the wettability of the spray-type tube 15 is sufficiently improved, in other words, when the spray-type tube 15 is prevented from drying out, the amount of refrigerant required is 3 times. Twice the refrigerant liquid can be sprayed. Therefore, the wettability of the spray tube 15 is sufficiently ensured.

In the above embodiment, the ratio between the full flow paths A1 and A2 of the full tube 13 and the spray flow path B of the spray tube 15 is set to 2: 1. It is not limited. Since it is necessary to spray a sufficient amount of refrigerant liquid so that the spray tube 15 does not dry, the number of the full flow passages formed by the full tube 13 is equal to the number of the spray flow passages formed by the spray tube 15. There is no special limitation as long as such conditions are satisfied. Further, the supply source of the high-pressure refrigerant liquid sprayed from the spray 14 does not need to be limited to the condenser 5. A high-pressure refrigerant liquid on the outlet side of the condenser 5,
That is, any refrigerant liquid before exiting the outlet of the condenser 5 and reaching the evaporator 2 may be used. If the refrigerator has it,
For example, the subcooler 63 (see FIG. 5) and the intercooler 6
(See FIG. 6) can be used as the supply source of the refrigerant liquid in this case.

FIG. 4 is a system diagram showing a refrigerator having the evaporator 2 according to the above embodiment. As shown in the figure,
The refrigerating machine condenses the high-temperature and high-pressure refrigerant gas compressed by the compressor 1 by exchanging heat with the cooling water in the condenser 5, and condenses the high-pressure refrigerant liquid thus condensed with the cold water in the evaporator 2. It is configured to evaporate by heat exchange and return to the compressor 1 as a low-pressure refrigerant gas. That is, although a refrigeration cycle similar to the conventional one is formed, in the refrigerator, a high-pressure refrigerant liquid is supplied to the evaporator 2 from the condenser 5 via the expansion valve 62, and the refrigerant liquid is sprayed. The evaporator 2 exhibits the above-described function described with reference to FIG.

FIG. 5 shows a configuration in which a subcooler 63 is provided between the condenser 5 and the evaporator 2 of the refrigerator shown in FIG. In the refrigerator, the high-pressure refrigerant at the outlet side of the subcooler 63 is supplied to the spray 14 of the evaporator 2 via the expansion valve 62. FIG. 6 shows a configuration in which the compressor 1 of the refrigerator shown in FIG. 4 is a multi-stage compressor and an intercooler 6 is provided between the condenser 5 and the evaporator 2. In the refrigerator, the intercooler 6
Is supplied to the spray 14 of the evaporator 2 through the expansion valve 62. Further, the refrigerator is a condenser 5
An expansion valve 64 is also provided between 1 and the intercooler 6.
In the refrigerators shown in FIGS. 5 and 6, the evaporator 2 exhibits the same function as that shown in FIG.

(222) FIG. 7 is a system diagram showing a centrifugal chiller according to an embodiment of the present invention, and FIG. 8 is an explanatory diagram extracting and showing a drive motor of a compressor in the centrifugal chiller shown in FIG. . As shown in both figures, the compressor 1 according to the present embodiment
Has a direct connection structure in which the drive motor 3 and the impeller 4 as a compression unit are connected without passing through the speed-increasing gear 9. Therefore, the drive motor 3 is required to have a high rotation speed.

The drive motor 3 has a stator space 26 for occupying the stator 3a and a rotor space 2 for occupying the rotor 3b including a gap between the stator 3a and the rotor 3b.
7, a partition member 25 is provided to separate the stator space 26 and the rotor space 27 from each other. A stator space 2 is provided at the center and lower part of the casing of the drive motor 3.
6, and two refrigerant liquid outlets 72a, 72b facing the stator space 26 at two upper left and right locations.
Are provided respectively. That is, the refrigerant liquid is supplied from the refrigerant liquid supply port 71 into the stator space 26 to cool the stator 3a, and then the refrigerant liquid can be discharged from the refrigerant liquid discharge ports 72a and 72b. . A refrigerant gas supply port facing the rotor space 27 is provided at the upper part of the casing on the right side of the stator 3a and the rotor 3b, and a refrigerant gas discharge port 74 facing the rotor space 27 is provided at the center of the casing on the left side. Are provided respectively. That is,
The coolant gas is supplied from the coolant gas supply port 73 into the rotor space 27 to flow in the gap between the rotor 3a and the stator 3b in the axial direction, thereby cooling the rotor 3b. This refrigerant gas can be discharged from the discharge port 74.

The refrigerant liquid for cooling reaches the refrigerant liquid supply port 71 from the outlet side of the condenser 5 via the pipe line 21, and the refrigerant liquid after cooling the stator 3a is supplied from the refrigerant liquid discharge ports 72a and 72b to the pipe. It is configured to reach the inlet side of the evaporator 2 through the passage 22. The refrigerant gas for cooling reaches the refrigerant gas supply port 73 from the outlet side of the evaporator 2 via the conduit 23, and the refrigerant gas after cooling the rotor 3b passes through the conduit 24 from the refrigerant gas outlet 74. It is configured to reach the suction section 1c of the compressor through the compressor.

Cooling rings 28a and 28b are fitted to the rotating shaft 32 of the rotor 3b so as to face the passage of the refrigerant gas. The cooling ring 28a, 28b has a lower heat capacity than the refrigerant liquid and a lower cooling performance. Of the cooling performance due to the cooling of the cooling medium is suppressed by increasing the surface area of the portion in contact with the refrigerant gas.

In this embodiment, the condenser 5
The refrigerant liquid flows into the stator space 26 through the conduit 21 and the refrigerant liquid supply port 71 to cool the stator 3a, and then the evaporator 2 flows through the refrigerant liquid discharge ports 72a and 72b and the conduit 22. Return to That is, the stator 3a is effectively cooled by the refrigerant liquid having a large heat capacity. At this time, since the refrigerant liquid does not flow out of the partition member 25 that defines the stator space 26, the refrigerant liquid does not come into contact with the rotating part, and therefore, the rotational resistance does not increase. In this case, the transfer of the refrigerant liquid from the condenser 5 to the stator space 26 and from the stator space 26 to the evaporator 2 is performed using the pressure difference between the two as a drive source.

On the other hand, the refrigerant flows into the refrigerant gas rotor space 27 from the evaporator 2 through the pipe 23 and the refrigerant gas supply port 73, and exchanges heat with one of the cooling rings 28a. At one end thereof, and flows along the axial direction to cool the contact portion and reach the other end of the gap. Further, the refrigerant gas flows from the other end of the gap to the other cooling ring 28b.
After the heat exchange with b, the refrigerant reaches the suction portion 1c of the compressor 1 via the refrigerant gas outlet 74. That is, since the rotor 3b is cooled by the refrigerant gas having a low heat capacity but a low viscosity, the compressor can be operated with a lower rotational resistance than the refrigerant liquid. Incidentally, in the present embodiment, since the drive motor 3 and the compression section are directly connected, the speed of the drive motor 3 is much higher than that of the case where the conventional speed increasing gear 9 (see FIG. 19) is employed. High speed is required. In this way, the higher the speed of the drive motor 3, the more the rotor 3
The effect of cooling b with the refrigerant gas becomes remarkable.
In this case, the flow of the refrigerant gas from the evaporator 2 to the suction portion 1c of the compressor 1 via the rotor space 27 is performed using the pressure difference between the two as a drive source.

FIG. 9 is a system diagram showing a centrifugal chiller according to an embodiment of the present invention. As shown in the figure, the refrigerator according to the present embodiment includes a refrigerant liquid pump 18 from the outlet side of the evaporator 2.
Is supplied into the stator space 26 of the drive motor 3 through the refrigerant liquid supply port 71 of the compressor 1 and the refrigerant liquid discharged from the refrigerant liquid outlets 72a and 72b is supplied to the inlet of the evaporator 2. Side. That is, the method of supplying the refrigerant liquid is different from that of the above-described embodiment, but the other components are the same.

Since the refrigerant liquid is pumped up by the refrigerant pump 18 provided in the middle of the pipe 21 extending from the outlet side of the evaporator 2 to the refrigerant supply port 71, the refrigerant liquid is surely supplied even when the refrigerator is started. Liquid can be supplied into the stator space 26. Incidentally, in the case of the embodiment shown in FIG. 7, depending on conditions such as the ambient temperature, the refrigerant liquid in the condenser 5 may be gasified when the refrigerator is started, and the stator space It is not guaranteed that the refrigerant supplied to the inside 26 is supplied in the state of the refrigerant liquid.

The above embodiment is a case of a centrifugal chiller. However, there is no particular limitation as long as the compressor is driven to rotate by a driving motor. Further, it is not necessary to limit the impeller 4 to the one directly connected. However, as the rotational speed of the drive motor increases, the features of the present invention become more remarkable.

(333) FIG. 10 is a longitudinal sectional view showing the drive motor of the compressor according to the embodiment of the present invention and its vicinity, and FIG. 11 is a transverse sectional view of its rotor and its vicinity. As shown in both figures, a rotor core 3d is provided at the center of the stator core 3c of the drive motor 3 along the radial direction.
And two pairs of opposing holes 33a and 33b are formed toward the surface of. A high-pressure refrigerant gas is supplied to each of the holes 33a and 33b. The high-pressure refrigerant gas is injected onto the surface of the rotor core 3d, and a gap between the high-pressure refrigerant gas and the stator core 3c is formed in the axial direction. It flows along the gap, flows out through the opening ends on both sides of the gap, and flows out of the drive motor 3 through the gas discharge ports 39a and 39b. At this time, the tips of the holes 33a and 33b are open to the grooves 34a and 34b formed on the inner peripheral surface of the stator core 3c. The grooves 34a and 34b are formed along the axial direction of the inner peripheral surface of the stator core 3c to both ends thereof. Further, as shown particularly clearly in FIG. 11, the inner peripheral surface of the stator core 3c is offset-processed with respect to the outer peripheral shape of the rotor core 3d which is a perfect circle indicated by a two-dot chain line in FIG. The gaps 35a and 35b are also formed between the two by this offset processing. Thus, a good static pressure bearing is formed by the high-pressure refrigerant gas supplied to the gap between the inner peripheral surface of the stator core 3c and the outer peripheral surface of the rotor core 3d, including the gaps 35a and 35b. That is, with this configuration, the high-pressure refrigerant gas injected from the distal ends of the holes 33a and 33b diffuses through the gaps 35a and 35b and the grooves 34a and 34b to the entire area of the gap with the surface of the stator core 3c. As a result, a sufficient pressure receiving area is secured, so that a hydrostatic bearing for supporting the rotor core 3d is formed. The impeller 4 of the compressor 1 is rotationally driven while the rotor core 3d of the high-pressure refrigerant gas is supported in this manner.

In the above embodiment, two pairs of holes 33a and 33b, which are high-pressure gas supply ports for the hydrostatic bearing, are provided at opposing positions on the inner peripheral surface of the stator core 3c.
Since two sets of such holes 33a and 33b need to face each other on the inner peripheral surface of the stator core 3c, it is necessary to provide an even number of holes at equal intervals in the circumferential direction, but the number is not particularly limited. . However, as in the above embodiment, even two sets can be used as a hydrostatic bearing having a sufficient load capacity.

An embodiment of the present invention relating to a refrigerator having a compressor driven by the drive motor 3 according to the above embodiment will be described in detail with reference to the drawings.

FIG. 12 is a system diagram showing a centrifugal chiller according to an embodiment of the present invention. As shown in the figure, the refrigerator condenses the high-temperature and high-pressure refrigerant gas compressed by the compressor 1 by exchanging heat with the cooling water in the condenser 5 and also condenses the high-pressure refrigerant liquid thus condensed. The expansion valve 62
Through heat exchange with cold water in the evaporator 2 to return to the compressor 1 as a low-pressure refrigerant gas, and has basically the same configuration as the refrigerator according to the related art. Things. Here, the compressor 1 compresses the refrigerant gas by rotating the impeller 4 of the compressor 1 with the drive motor 3, and is configured as a direct connection type that shares the rotation shafts 32 of both. Note that the solid line in the drawing is the refrigerant liquid pipe, and the dotted line is the refrigerant gas pipe.

The high-pressure refrigerant gas discharged from the compressor 1 is supplied to the condenser 5, and is branched off from a pipe toward the condenser 5 and supplied to the holes 33 a and 33 b of the drive motor 3. Thus, the high-pressure refrigerant gas discharged from the compressor 1 becomes a working fluid of a hydrostatic bearing that supports the rotor core 3d of the drive motor 3. However, in order to start the compressor 1, the drive motor 3 must be driven, and in order to drive the drive motor 3, its rotor core 3d must be supported by a hydrostatic bearing. Therefore, the drive motor 3
The high pressure refrigerant gas separately stored in the pressure tank 36 is used as the refrigerant gas for starting the operation. For this reason, the pressure tank 36 is connected via valves 38a and 38b in the middle of the pipeline from the compressor 1 to the drive motor 3, and the pressure tank 36
A valve 38c is provided in the conduit leading to the drive motor 3 on the side of the condenser 5 rather than the branch path to the valve 38c. Thus, when the drive motor 3 starts, the valve 38a is opened and the valves 38b,
38c is closed, the refrigerant gas in the pressure tank 36 is supplied to the holes 33a and 33b of the drive motor 3, and the drive motor 3 is started in a state where the rotor core 3d is floated by a static pressure bearing formed by the same. . As a result, the pressure of the refrigerant gas discharged from the compressor 1 becomes a predetermined high pressure, and the operation shifts to the steady operation. Then, the valves 38b and 38c are opened and the valve 38 is opened.
Close a. Thus, the high pressure refrigerant gas discharged from the compressor 1 is filled in the pressure tank 36 to prepare for the next start, and supplied to the holes 33a and 33b of the drive motor 3 to operate the hydrostatic bearing for supporting the rotor core 3d. Fluid. On the other hand, the refrigerant gas functioning as the working fluid of the hydrostatic bearing that supports the rotor core 3 d is configured to return to the evaporator 2.

According to the present embodiment, when starting the compressor 1,
The rotor core 3d is supported by the high-pressure refrigerant gas supplied from the pressure tank 36 and starts rotating. During a steady operation, the high-temperature and high-pressure refrigerant gas compressed by the compressor 1 is supplied to the rotor core 3d.
And continues to support the rotor core 3d. At this time, the refrigerant gas functioning as a working fluid of the hydrostatic bearing is returned to the evaporator 2.

FIG. 13 is a system diagram showing a centrifugal chiller according to the next embodiment of the present invention. In the figure, the same parts as those in FIG. 12 are denoted by the same reference numerals, and redundant description is omitted. As shown in the figure, the refrigerant gas of the hydrostatic bearing that supports the rotor core 3d of the drive motor 3 of the compressor 1 of the refrigerator is compressed by a separate gas compressor 37 from the saturated refrigerant gas of the condenser 5. The refrigerant gas, which has been obtained as a working fluid for the hydrostatic bearing of the rotor core 3 d, is returned to the condenser 5.

FIG. 14 is a system diagram showing a centrifugal chiller according to the next embodiment of the present invention. In the figure, the same parts as those in FIG. 12 are denoted by the same reference numerals, and redundant description is omitted. As shown in the figure, the refrigerant gas of the hydrostatic bearing that supports the rotor core 3d of the drive motor 3 of the compressor 1 of the refrigerator is obtained by compressing the refrigerant gas of the evaporator 2 by another gas compressor 37. In addition, the refrigerant gas functioning as the working fluid of the static pressure bearing of the rotor core 3 d is returned to the evaporator 2.

FIG. 15 is a system diagram showing a centrifugal chiller according to the next embodiment of the present invention. In the figure, the same parts as those in FIG. 12 are denoted by the same reference numerals, and redundant description is omitted. As shown in the figure, the refrigerant gas of the hydrostatic bearing that supports the rotor core 3d of the drive motor 3 of the compressor 1 of the refrigerator is obtained by compressing the refrigerant gas of the evaporator 2 by another gas compressor 37. The refrigerant gas, which has been obtained as a working fluid for the hydrostatic bearing of the rotor core 3 d, is returned to the condenser 5.

The present invention is not limited to the above embodiment. Basically, other modifications are also included in the technical concept of the present invention as long as the compressor 1 is driven to rotate by the drive motor 3. Naturally, the present invention can be suitably applied not only to the turbo refrigerator but also to a gas compressor such as a screw refrigerator.

(444) FIG. 16 is a system diagram showing an example of the configuration of a centrifugal chiller according to an embodiment of the present invention.
FIG. 17 is an enlarged view extracting and showing the compressor and its vicinity in FIG. 16. As shown in both figures, the refrigerator according to the present embodiment is obtained by adding a jet pump 47 using lubricating oil pumped by the oil pump 7 as a driving fluid to the refrigerator according to the conventional technique shown in FIG. FIG. 19 shows another configuration.
Is the same as the prior art shown in FIG.

As shown in FIGS. 16 and 17, a branch pipe 48 is connected to a pipe on the discharge side of the oil pump 7 constituting a conventional lubrication system. Is supplied. Piping 4
9 has one end open to the lower part of the suction part of the compressor 1 and the other end connected to the suction part of the jet pump 47. The pipe 50 has one end opening to the discharge port of the jet pump 47 and the other end opening above the oil tank 1b. Thus, the lubricating oil adhering to the periphery of the suction portion 1c of the compressor 1, particularly the lubricating oil that descends by its own weight and accumulates in the lower part, is sucked by the jet pump 47 through the pipe 49 and discharged to the oil tank 1b and collected. . The collection of the lubricating oil may be performed as long as the oil pump 7 is driven, and even after the refrigerator is stopped.

(555) With the increase in the capacity of the refrigerator, a parallel refrigerator having two compressors connected in parallel to one evaporator and one condenser has recently been proposed as shown in FIG. In the parallel type refrigerator, when shifting from the single operation mode to the parallel operation mode, the internal pressure of the evaporator may suddenly change with the subsequent start of the compressor, which may cause a trip of the refrigerator. Here, "trip" means that the operation of the refrigerator is automatically stopped when the evaporation pressure of the evaporator falls below a predetermined value and rises above the predetermined value. As described above, when shifting from the single operation mode to the parallel operation mode, the evaporation pressure may drop below a predetermined value, and in this case, the operation of the refrigerator is stopped. The stoppage of operation due to the occurrence of such a trip causes a reduction in the efficiency of the refrigerator.

Here, a description will be given of a method of controlling a parallel type refrigerator capable of smoothly shifting to the parallel operation without causing a trip when shifting from the single operation mode to the parallel operation mode.

As shown in FIG. 18, the refrigerator is a parallel type turbo refrigerator and a multi-stage (two-stage) turbo refrigerator. Therefore, it has one condenser 5 and evaporator 2 and two two-stage turbo compressors 1A and 1B connected in parallel to these, and corresponds to the two-stage turbo compressors 1A and 1B. It has two intercoolers 6A and 6B provided as follows. That is, the parallel centrifugal chiller has two symmetric refrigerant systems.
In the drawing, the pipeline through which the refrigerant gas flows is shown by a dotted line, and the pipeline through which the refrigerant liquid flows is shown by a solid line.

The operation of one of the above refrigerant systems will be described. Two-stage turbo compressor 1
A sucks the refrigerant gas supplied from the evaporator 2 through the suction part 1c, compresses it, and supplies it to the condenser 5 as a high-temperature and high-pressure refrigerant gas through the discharge port 1d. The high-temperature and high-pressure refrigerant gas is condensed and liquefied by exchanging heat with the cooling water in the condenser 5, decompressed by the orifice 5 a to be in a gas-liquid mixed state, and this refrigerant is supplied to the intercooler 6 A. In the intercooler 6A, the refrigerant gas in the refrigerant in a gas-liquid mixed state is separated, returned to the compression section 1c of the two-stage turbo compressor 1A via the intermediate suction valve 75, and subjected to multi-stage compression. On the other hand, the refrigerant liquid discharged from the intercooler 6 </ b> A passes through the orifice 76 in the immediate vicinity of the evaporator 2 and is further reduced in pressure and reaches the evaporator 2. The refrigerant liquid supplied to the evaporator 2 in this manner evaporates by exchanging heat with cold water therein,
The refrigerant gas is sucked into the two-stage turbo compressor 1A. Thus, the chilled water flowing through the pipe in contact with the refrigerant in the evaporator 2 is cooled to a predetermined temperature.

The bypass pipe 77 allows the refrigerant liquid reaching the evaporator 2 to bypass the orifice 76.
8 can be opened and closed. The hot gas bypass pipe 79 is a pipe that directly connects the condenser 5 and the evaporator 2 and can be opened and closed by an on-off valve 80. Thus, when the on-off valve 80 is in the open state, the high-temperature and high-pressure refrigerant gas of the condenser 5 can be directly supplied to the evaporator 2, which ensures a smooth operation at a light load. You. That is,
The refrigerant gas that has passed through the hot gas bypass pipe 79 does not contribute to the work as a refrigerator. However, by including the refrigerant gas as a load of the compressor 3, surging of the compressor 1A is prevented. Here, “surging” refers to a phenomenon that occurs due to an insufficient amount of refrigerant gas sucked by the compressor 3 and causes the compression operation to be intermittent.

Although the above description has been made with respect to one of the two refrigerant systems, the structure and operation of the other refrigerant systems are exactly the same. That is, an intercooler 6B is provided corresponding to the intercooler 6A, and the same applies to the intermediary suction valve 7
5, an orifice 82 corresponding to the orifice 76, a bypass line 83 for the bypass line 77, an on-off valve 84 for the on-off valve 78, a hot gas bypass line A hot gas bypass pipe 85 is provided for 79, and an on-off valve 86 is provided for the on-off valve 80. Also, the orifice 5b corresponds to the orifice 5a.

The refrigerator is operated in the following manner. Now, assume that the compressor 1A is a starter and the compressor 1B is a starter. When the load is light, the single mode operation is performed by the compressor 1A, and when the load is a predetermined value or more, the compressor 1A is operated.
A, 1B parallel mode operation is performed. Therefore, first, a prerotation vane (hereinafter, simply referred to as a vane) and an intermediate suction valve 75 immediately before the start of the compressor 1A.
And the hot gas bypass line 7
9 and diffuser fully open. The suction portion 1c is closed by the closing of the pre-rotation vane. The "diffuser" adjusts the flow rate of the refrigerant gas from the discharge port 1d. The gas flow rate passing through the discharge port 1d is increased by narrowing the discharge port 1d at a small load when the suction gas amount is small. This is to prevent surging even if the amount of suction gas is small.

The compressor 1A is started in the above state, and the opening of the vane is adjusted according to the load. The opening of the hot gas bypass pipe 79 and the opening of the diffuser are adjusted in conjunction with the opening of the vane. Specifically, the opening of the on-off valve 80 is adjusted. At this time, interrupter control (to be described in detail later) may be applied to the control of the on-off valve 80 to gradually reduce the opening. The intermediate suction valve 75 is opened on condition that the differential pressure between the condenser 5 and the evaporator 2 reaches a predetermined value, and returns the refrigerant gas from the intercooler 6A to the compressor 1A.

The opening and closing valve 78 basically opens and closes depending on the inlet temperature of the cooling water, but is forcibly opened when the pressure of the evaporator 2 becomes lower than a predetermined value. Thus, the high-pressure refrigerant liquid at the outlet side of the intercooler 6A can be supplied to the evaporator 2 without passing through the orifice 76, and an abnormal decrease in the internal pressure of the evaporator 2 can be prevented.

When shifting to the parallel operation mode when the increase in load is detected, first, the vane opening of the compressor 1A is set to 30 degrees.
Squeeze to about%. The opening of the hot gas bypass pipe 79 and the opening of the diffuser are also linked to the opening of the vane. On the other hand, the vane and the intermediate suction valve 81 of the later-compressed compressor 1B are fully closed, and the hot gas bypass pipe line 85 and the diffuser are fully opened. That is, the first compressor 1
The state is the same as that immediately before the activation of A. The compressor 1B is started in such a state.

After starting the compressor 1B, the vane opening of the compressors 1A and 1B is increased in accordance with the load. The vane opening is controlled by interrupter control. The “interrupter control” refers to control in which a control target is set to a target state by alternately repeating driving for a predetermined time and stopping the control object for a predetermined time. In this case, when the openings of the suction portions 1c, 1c of the compressors 1A, 1B are opened until they reach the target opening, the opening operation is continued for a predetermined time, and then the opening operation is stopped for the next predetermined time, and this operation is performed. This means that the vane is gradually opened by repeating the stop and stop.

After the subsequent compressor 1B is started, the compressor 1B
The opening of the vanes A and 1B is controlled according to the load, and the opening of the hot gas bypass pipes 79 and 85 and the diffusers of the compressors 1A and 1B are controlled in accordance with the respective openings of the vanes. . Also, the intermediate suction valve 75,
Reference numeral 81 denotes an open state on condition that the differential pressure between the condenser 5 and the evaporator 2 reaches a predetermined value, and returns the refrigerant gas from the intercoolers 6A and 6B to the compressors 1A and 1B, respectively. The control of the on-off valve 84 is similar to the control of the on-off valve 78, and basically opens and closes depending on the inlet temperature of the cooling water. Become. As a result, the intercooler 6 does not pass through the orifice 82.
The high-pressure refrigerant liquid on the outlet side of B can be supplied to the evaporator 2, and an abnormal decrease in the internal pressure of the evaporator 2 can be prevented.

According to such an operating method, fluctuations in the evaporating pressure of the evaporator due to the subsequent start of the compressor can be reduced as much as possible, without causing harmful phenomena to the operation such as tripping. Smooth driving can be continued.

[0090]

As described in detail with the above embodiments, the invention described in [Claim 1] is a shell-and-tube type evaporator that boils and evaporates this refrigerant liquid while immersed in the refrigerant liquid. A liquid-filled tube specially designed for liquid filling is arranged at a relatively lower part in the shell, and a liquid-filled tube specially designed for spraying is used to evaporate a refrigerant liquid attached by spraying from an upper spray. A spray tube is disposed at a relative upper portion in the shell, and the number of flow passages included in the flooded flow passage formed by the aggregate of the flooded tubes and the aggregate of the spray tubes are further increased. The number of the flow paths included in the spray type flow path to be formed is adjusted so that the number of the flow paths included in the spray type flow path is equal to or less than the number of the flow paths included in the full flow type flow path. , Full Since the cold water flowing out of the flow passage or the spray flow passage is configured to flow into the spray flow passage or the full flow passage, the heat flux is supplied to each of the flow passages formed by the full flow tube and the spray tube. Not only can it be brought to the optimum point, but even if part of the filled tube is not immersed in the refrigerant liquid at partial load, the surface of the filled tube in such a state will be exposed from the upper spray. It can be wetted by the refrigerant liquid to be sprayed, and heat conduction by film evaporation is performed also in this portion. Further, the amount of the refrigerant liquid supplied to the spray is an amount sufficient to ensure the wettability of the spray tube. As a result, the number of tubes can be reduced, which can contribute to cost reduction, downsizing, and weight reduction.
Further, even at the time of partial load, an ineffective portion of the liquid-filled tube in heat exchange can be removed, so that heat exchange performance can be improved. Further, the spray tube does not dry out from the spray, and a sufficient amount of refrigerant can be sprayed to ensure good wettability.

[0091] According to the invention described in [Claim 2], in the evaporator described in [Claim 1], the spray is such that a high-pressure refrigerant liquid on the outlet side of a condenser, an intercooler or a subcooler is sprayed. With this configuration, the same amount or more of the refrigerant liquid as required in the spray type flow passage can be sprayed from the spray toward the spray type tube. As a result, the same effects as those of the invention described in [Claim 1] can be obtained.

According to a third aspect of the present invention, in the evaporator according to the first or second aspect, the liquid-filled tube has a boiling transmission having a large number of depressions on the surface of the tube body. Since the refrigerant liquid is formed by the heat-promoting tube, the refrigerant liquid enters into the depression, and the refrigerant liquid thus entered converges with the cold water flowing through the liquid-filled tube and evaporates to efficiently boil the refrigerant liquid. Therefore, the same effect as the invention described in the above [Claim 1] or [Claim 2] can be obtained.

According to a fourth aspect of the present invention, in the evaporator according to the first or second aspect, the spray type tube has a fin provided on the surface of the tube body so as to protrude in the radial direction. The height is optimized and the number is increased, and a part of the fins is cut out in the axial direction so that the attached liquid refrigerant can move along this notch. Since a liquid film of the liquid can be formed on the entire surface of the spray tube, the liquid film can be effectively vaporized, and the above [Claim 1] or [Claim 2] The same effect as the invention described in (1) can be obtained.

According to a fifth aspect of the present invention, in a compressor that compresses and discharges refrigerant gas sucked by rotating a compression unit such as an impeller by a drive motor, the stator of the drive motor is occupied. A partition member is provided between the stator space to be separated and the rotor space that occupies the rotor including the gap between the stator and the rotor. To cool the stator, and then discharge this refrigerant liquid from the refrigerant liquid outlet, while supplying refrigerant gas to the rotor space from the refrigerant gas supply port to feed the shaft along the gap between the stator and the rotor. The rotor space is cooled by flowing in the direction and then the refrigerant gas is discharged from the refrigerant gas outlet, so that the stator space and the rotor space are separated by a partition member and become independent separate spaces. And
The stator is cooled by a refrigerant liquid having a large heat capacity, and a portion of the rotor, particularly a portion facing a gap between the rotor and an inner peripheral surface of the stator is cooled by a low-viscosity refrigerant gas.

As a result, it is possible to secure the cooling performance of the rotor without impairing the cooling performance of the stator, reduce the rotational resistance, and reduce the rotational loss of the drive motor.

In the invention described in [Claim 6], in the invention described in [Claim 5], since the impeller of the compression unit is directly connected to the rotating shaft of the drive motor, it is necessary to rotate the drive motor at high speed. However, since the rotor is cooled by the low-viscosity refrigerant gas, an increase in rotation loss of the drive motor can be suppressed.

According to the invention described in [Claim 7], in the compressor described in [Claim 5] or [Claim 6], the cooling ring is fixed to the rotating shaft facing the passage of the refrigerant gas. Since the refrigerant gas also exchanges heat with the ring, the rotor is also cooled by the refrigerant gas through the ring.

Therefore, the cooling performance of the refrigerant gas having a small heat capacity can be complemented by increasing the surface area of the portion to be cooled.

The invention described in [Claim 8] includes the compressor according to any one of [Claim 5] to [Claim 7], and includes a high-temperature and high-pressure refrigerant gas compressed by the compressor. Is condensed by exchanging heat with cooling water in a condenser, and the condensed high-pressure refrigerant liquid is evaporated by exchanging heat with cold water in an evaporator and returned to the compressor as a low-pressure refrigerant gas. In the refrigerator configured as described above,
The refrigerant liquid is supplied from the outlet side of the condenser into the stator space of the drive motor and the refrigerant liquid discharged from the refrigerant liquid outlet is discharged to the evaporator inlet, while the rotor space of the drive motor is discharged from the evaporator outlet side. The compressor is configured to supply the refrigerant gas to the compressor and discharge the refrigerant gas to the suction portion of the compressor. Therefore, the stator is cooled by the refrigerant liquid having a large heat capacity supplied from the condenser, and the rotor, especially the stator, The portion facing the gap with the peripheral surface is cooled by a low-viscosity refrigerant gas supplied from the compressor. At this time, the refrigerant liquid is supplied into the stator space by the differential pressure between the condenser and the evaporator, and the refrigerant liquid that has cooled the stator is discharged to the evaporator. The refrigerant gas that has cooled the rotor is discharged to the suction section of the compressor.

As a result, the cooling performance of the rotor can be ensured without impairing the cooling performance of the stator, and an increase in rotational resistance can be suppressed. In addition, the cooling liquid that has cooled the stator is returned to the evaporator, and the refrigerant gas that has cooled the rotor is discharged to the suction part of the compressor, and each functions as a refrigerant for the refrigerator. It is not necessary to supply the medium in a separate system, and it is possible to increase the efficiency of the refrigerator without increasing the cost of the whole refrigerator.

According to a ninth aspect of the present invention, there is provided a compressor according to any one of the fifth to seventh aspects, wherein the high-temperature and high-pressure refrigerant gas is compressed by the compressor. Is condensed by exchanging heat with cooling water in a condenser, and the condensed high-pressure refrigerant liquid is evaporated by exchanging heat with cold water in an evaporator and returned to the compressor as a low-pressure refrigerant gas. In the refrigerator configured as described above,
The refrigerant liquid pumped by the refrigerant pump from the outlet side of the evaporator is supplied into the stator space of the drive motor via the refrigerant liquid supply port of the compressor, and the refrigerant liquid is discharged to the evaporator.
At this time, since the refrigerant liquid is pumped by the refrigerant pump from the outlet side of the evaporator, the refrigerant liquid can be reliably supplied into the stator space even when the refrigerator is started. The refrigerant liquid that has cooled the stator is supplied to the evaporator, and the refrigerant gas that has cooled the rotor is supplied to the compression section of the compressor, and each functions as a refrigerant for the refrigerator.

According to the tenth and eleventh aspects of the present invention, in a compressor for compressing a refrigerant gas in a compression section by rotation of a drive motor, a high-pressure refrigerant gas is fixed to a rotor core of the drive motor. A static pressure bearing that supplies the refrigerant gas to the working fluid by supplying it to the gap between the rotor core and the rotor core is configured to support the rotor core with this static pressure bearing. It can be supported by a static pressure bearing using a refrigerant gas of the same type as the refrigerant gas compressed by the compressor.

As a result, the rotor core can be supported by the bearing using the refrigerant originally required for the compressor, and the bearing required for supporting the rotor core in the prior art and the accompanying bearing are required. Since the lubrication system can be eliminated, the compressor can have a simple structure and can solve the problem associated with the refrigerant being dissolved into the lubricating oil.

According to a twelfth aspect of the present invention, in the refrigerator according to the eleventh aspect, the high-pressure refrigerant gas supporting the rotor core at the time of starting the compressor has a pressure stored separately. While the refrigerant gas in the tank was used, the high-pressure refrigerant gas supporting the rotor core during the steady operation of the compressor used the refrigerant gas discharged from the compressor as it was and functioned as the working fluid of the rotor core. Since the refrigerant gas is configured to return to the evaporator, the rotor core is floated by the high-pressure refrigerant gas stored in the pressure tank when the compressor is started, and the high-temperature and high-pressure refrigerant gas is compressed by the compressor during normal operation of the compressor. Thus, the rotor core of the drive motor can be continuously supported. In this case, the refrigerant gas functioning as the working fluid of the hydrostatic bearing is discharged to the evaporator.

As a result, in addition to the same effect as the invention described in [Claim 11], it is not necessary to prepare another gas compressor to obtain the refrigerant gas to be supplied to the static pressure bearing of the rotor core. This also has the effect of contributing to cost reduction.

According to a thirteenth aspect of the present invention, in the refrigerator according to the eleventh aspect, the high-pressure refrigerant gas for supporting the rotor core at the time of starting the compressor has a pressure stored separately. While the refrigerant gas in the tank is used, the high-pressure refrigerant gas that supports the rotor core during steady-state operation of the compressor is obtained by compressing the saturated refrigerant gas of the condenser with another gas compressor. The refrigerant gas that has functioned as the working fluid is returned to the condenser, so when the compressor starts, the rotor core is floated by the high-pressure refrigerant gas stored in the pressure tank, and when the compressor is in steady operation, the condenser is saturated. The rotor core of the drive motor can be continuously supported by the refrigerant gas obtained by compressing the refrigerant gas by another gas compressor. In this case, the refrigerant gas functioning as the working fluid of the hydrostatic bearing is discharged to the condenser.

As a result, according to the present invention, [Claim 1
In addition to the same effects as those of the invention described in [1], since the refrigerant gas of the hydrostatic bearing that supports the rotor core is supplied from the condenser and returned to the condenser, loss during this period can be minimized. Not only that, since the refrigerant gas compressed by the gas compressor is at a high pressure, the gas compressor may be small,
This also has the effect of being advantageous in terms of cost.

According to a fourteenth aspect of the present invention, in the refrigerator described in the eleventh aspect, the high-pressure refrigerant gas supporting the rotor core at the time of starting the compressor has a pressure stored separately. While the refrigerant gas in the tank is used, the high-pressure refrigerant gas supporting the rotor core during the steady operation of the compressor is obtained by compressing the refrigerant gas of the evaporator by another gas compressor, and Since the refrigerant gas functioning as the working fluid is configured to return to the evaporator, the rotor core is floated by the high-pressure refrigerant gas stored in the pressure tank when the compressor is started, and the refrigerant gas in the evaporator during the steady operation of the compressor. Can be continuously supported on the rotor core of the drive motor by refrigerant gas obtained by compressing the rotor core with another gas compressor. In this case, the refrigerant gas functioning as the working fluid of the hydrostatic bearing is discharged to the evaporator.

As a result, according to the present invention, [Claim 1
In addition to the same effects as the invention described in 1), the pressure difference of the refrigerant gas supplied to the hydrostatic bearing that supports the rotor core can be increased, which can contribute to downsizing of the gas bearing, There is also an effect that the loss can be reduced.

[0110] The invention described in [Claim 15] is a refrigerator according to [Claim 11], wherein the high-pressure refrigerant gas for supporting the rotor core at the time of starting the compressor has a pressure stored separately. While the refrigerant gas in the tank is used, the high-pressure refrigerant gas supporting the rotor core during the steady operation of the compressor is obtained by compressing the refrigerant gas of the evaporator by another gas compressor, and Since the refrigerant gas functioning as a working fluid is configured to return to the condenser, the rotor core is floated by the high-pressure refrigerant gas stored in the pressure tank when the compressor starts, and the refrigerant gas in the evaporator during the steady operation of the compressor. Can be continuously supported on the rotor core of the drive motor by refrigerant gas obtained by compressing the rotor core with another gas compressor. In this case, the refrigerant gas functioning as the working fluid of the hydrostatic bearing is discharged to the condenser.

As a result, according to the present invention, [Claim 1
In addition to the same effects as those of the invention described in [1], an effect that the loss can be minimized is also exhibited.

[0112] The invention described in [Claim 16] and [Claim 17] compresses the refrigerant gas sucked into the suction part, discharges the refrigerant gas as a high-temperature and high-pressure refrigerant gas to the condenser, and the oil tank in the casing. In a compressor configured to supply lubricating oil stored in a lubricating portion such as a bearing portion by driving an oil pump, lubricating oil pumped by an oil pump between the suction portion of the refrigerant gas and the oil tank is provided. A jet pump as a driving fluid is provided, and the lubricating oil present in the suction part is collected in the oil tank by driving the jet pump. Therefore, the lubricating oil present in the suction part is lubricated by the oil pump. It can be collected in an oil tank by a jet pump using oil as a driving fluid. As a result, the lubricating oil present in the suction section can be accurately collected in the oil tank.

[0113] The invention described in claim 18 is the method for operating a refrigerator according to claim 17, wherein the operation of the oil pump is maintained for a certain period of time even after the refrigerating operation of the refrigerator is stopped. Is maintained, the lubricating oil present in the suction portion of the compressor can be continuously collected in the oil tank by the continuous operation of the oil pump even after the operation of the refrigerator is stopped. As a result, it is possible to completely collect the lubricating oil adhering to the vicinity of the suction part with the operation of the refrigerator.

[Brief description of the drawings]

FIG. 1 is an explanatory view conceptually showing an embodiment of the present invention.

FIG. 2 is a side view (a) showing an example of a liquid-filled tube used in the embodiment of the present invention with a part cut away, and a side view (b) showing an example of a spray-type tube.

FIG. 3 is an explanatory view conceptually showing a flow passage according to the embodiment of the present invention.

FIG. 4 is a block diagram showing a refrigerator according to the embodiment of the present invention.

FIG. 5 is a block diagram showing a refrigerator according to the embodiment of the present invention.

FIG. 6 is a block diagram showing a refrigerator according to the embodiment of the present invention.

FIG. 7 is a system diagram showing an example of a configuration of a centrifugal chiller according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram extracting and showing a drive motor of a compressor in the turbo refrigerator shown in FIG. 14;

FIG. 9 is a system diagram showing an example of a configuration of a centrifugal chiller according to an embodiment of the present invention.

FIG. 10 is a longitudinal sectional view showing a drive motor of the compressor according to the embodiment of the present invention and a portion in the vicinity thereof.

FIG. 11 is a cross-sectional view of the rotor shown in FIG. 17 and its vicinity.

FIG. 12 is a system diagram showing a refrigerator according to an embodiment of the present invention.

FIG. 13 is a system diagram showing a refrigerator according to the embodiment of the present invention.

FIG. 14 is a system diagram showing a refrigerator according to an embodiment of the present invention.

FIG. 15 is a system diagram showing a refrigerator according to an embodiment of the present invention.

FIG. 16 is a system diagram showing an example of a configuration of a centrifugal chiller according to an embodiment of the present invention.

FIG. 17 is an enlarged view showing a compressor and its vicinity in FIG.

FIG. 18 is an explanatory diagram illustrating a control system of a parallel refrigerator.

FIG. 19 is a system diagram showing an example of a configuration of a centrifugal chiller according to the related art.

FIG. 20 is an explanatory view conceptually showing a liquid-filled shell-and-tube evaporator according to a conventional technique applied to a refrigerator.

FIG. 21 is an explanatory view conceptually showing one spray-type shell-and-tube evaporator according to a conventional technique applied to a refrigerator.

FIG. 22 is an explanatory view conceptually showing another spray type shell-and-tube evaporator according to the prior art applied to a refrigerator.

FIG. 23 is an explanatory diagram extracting and showing a drive motor of a compressor in the turbo refrigerator.

FIG. 24 is an explanatory view conceptually showing a hydrostatic bearing.

FIG. 25 is an explanatory view conceptually showing an oil recovery apparatus according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 1a Casing 1b Oil tank 1c Suction part 2 Evaporator 2a Opening 2b Opening 2c Opening 2d Tube plate 3 Drive motor 3a Stator 3b Rotor 3c Stator core 3d Rotor core 3e Hole 3f, g Bearing 4 Impeller 5 Condenser 6 Intercooler 7 Oil pump 8a, b Impeller bearing 9 Acceleration gear 11 Shell 12 Refrigerant liquid 13 Tube (full type) 13a Tube body 13b Tube recess 14 Spray 15 Tube (spray type) 15a Tube Main body 15b Tube fin 15c Fin cutout 16 Liquid film 17 Liquid reservoir 18 Refrigerant liquid pump 19 Jet pump 21 Pipe (motor cooling supply) 22 Pipe (motor cooling return) 23 Pipe (stator cooling supply) 24 Pipe ( Stator cooling return) 25 Partition material 26 Stator space 27 Rotor space 8a, b cooling ring 31 static pressure bearing 32 rotating shaft 33a, b hole 34a, b groove 35a, b gap 36 pressure tank 37 gas compressor 38a, b, c valve 39a, b gas outlet 41a, b, c valve 42 Dryer 43 Ejector 44 Valve 45 Valve 46 Equalizing piping 47 Jet pump 48 Piping (drive fluid) 49 Piping (suction part) 50 Piping (discharge part) 51 Cold water inlet 52 Water chamber 53 Water chamber 54 Water chamber 55 Water chamber 56 Cold water outlet 61 Pipe line (refrigerant liquid) 62 Expansion valve 63 Subcooler 64 Expansion valve

Continuation of the front page (72) Inventor Hideki Tachibana 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Takasago Works (72) Inventor Kazuhiro Sakamoto 2-1-1, Araimachi Shinhama, Takasago-shi, Hyogo Mitsubishi Heavy Industries Co., Ltd. Takasago Factory

Claims (18)

[Claims] 1. A shell-and-tube type evaporator, wherein a liquid-filled tube specially designed for a liquid-filled type so as to boil and evaporate the refrigerant liquid in a state of being immersed in the refrigerant liquid is provided at a relative lower portion in the shell. A spray-type tube specially designed for spraying is provided at a relatively upper portion in the shell so as to evaporate a refrigerant liquid adhered by spraying from an upper spray, and a liquid-filled tube is further provided. The number of flow paths included in the liquid-filled flow path formed by the aggregate of the above-mentioned and the number of flow paths included in the spray-type flow path formed by the above-described aggregate of the spray-type tubes are included in the spray-type flow path. The number of the flow passages to be filled should be equal to or less than the number of the flow passages included in the full flow passage, and the cold water flowing out of the full flow passage or the spray flow passage should be filled with the spray flow passage or the full flow passage. liquid Evaporator, characterized by being configured so as to flow into the flow passage. 2. The evaporator according to claim 1, wherein the spray is configured to spray a high-pressure refrigerant liquid from a condenser, an intercooler, or a subcooler. . 3. The evaporator according to [1] or [2], wherein the liquid-filled tube is formed by a boiling heat transfer promoting tube having a large number of depressions on the surface of the tube body. And evaporator. 4. The evaporator according to claim 1 or 2, wherein the spray tube has an optimum number of fins provided on the surface of the tube body so as to protrude in the radial direction. An evaporator characterized in that a refrigerant liquid attached to a portion of the fin is cut out in the axial direction and can be moved along the notch. 5. A compressor that compresses and discharges refrigerant gas drawn in by rotating a compression section such as an impeller by a drive motor, wherein a stator space for occupying a stator of the drive motor, a stator, A partition member is provided between the rotor space and the rotor space including the gap between the rotors to occupy the rotor, and the two spaces are separated from each other. After cooling, the refrigerant liquid is discharged from the refrigerant liquid discharge port, and the refrigerant gas is supplied to the rotor space from the refrigerant gas supply port, and is circulated in the axial direction along the gap between the stator and the rotor to rotate. A compressor configured to cool the compressor and then discharge the refrigerant gas from the refrigerant gas outlet. 6. The compressor according to claim 5, wherein the impeller of the compression section is directly connected to the rotating shaft of the drive motor. 7. The compressor according to claim 5 or 6, wherein the cooling ring is fixed to the rotating shaft of the electric motor so as to face the passage of the refrigerant gas. 8. A compressor according to any one of claims 5 to 7, wherein the high-temperature and high-pressure refrigerant gas compressed by the compressor is heat-exchanged with cooling water by a condenser. In the refrigerating machine, the high-pressure refrigerant liquid thus condensed is exchanged with cold water by an evaporator to evaporate and return to the compressor as a low-pressure refrigerant gas. The refrigerant liquid is supplied from the outlet side of the compressor to the stator space of the drive motor through the refrigerant liquid supply port of the compressor, and the refrigerant liquid discharged from the refrigerant liquid discharge port is supplied to the inlet side of the evaporator, while The refrigerant gas is supplied from the outlet side of the compressor to the rotor space of the drive motor via the refrigerant gas supply port of the compressor, and the refrigerant gas discharged from the refrigerant gas discharge port is discharged to the suction part of the compressor. Characterized by Refrigerator that. 9. A compressor according to any one of [5] to [7], wherein the refrigerant gas of the high-temperature and high-pressure gas compressed by the compressor is cooled and cooled by a condenser. In the refrigerating machine configured to condense by exchanging, and to evaporate by exchanging the high-pressure refrigerant liquid thus condensed with cold water in an evaporator to return to the compressor as a low-pressure refrigerant gas, The refrigerant liquid pumped up by the refrigerant pump from the outlet side of the evaporator is supplied into the stator space of the drive motor via the refrigerant liquid supply port of the compressor, and the refrigerant liquid discharged from the refrigerant liquid discharge port is discharged to the evaporator. On the other hand, the refrigerant gas is supplied from the outlet side of the evaporator to the rotor space of the drive motor through the refrigerant gas supply port of the compressor, and the refrigerant gas discharged from the refrigerant gas discharge port is discharged to the suction part of the compressor. like Refrigerator is characterized in that form. 10. A compressor for compressing refrigerant gas in a compression section by rotation of a drive motor, wherein high-pressure refrigerant gas is supplied to a gap between a rotor core and a stator core of the drive motor, and the refrigerant gas is supplied to the gap. A compressor characterized by forming a hydrostatic bearing as a working fluid and supporting the rotor core with the hydrostatic bearing. 11. A high-temperature and high-pressure refrigerant gas compressed by a compressor driven by a driving motor is condensed by exchanging heat with cooling water in a condenser, and the high-pressure refrigerant liquid condensed in this way is evaporated by an evaporator. In a refrigerator configured to evaporate by heat exchange with cold water and return to the compressor as a low-pressure refrigerant gas, a rotor core of a drive motor is provided in a gap between the rotor core and the stator core. A refrigerating machine characterized in that it is configured to be supported by a static pressure bearing formed by supplying a high-pressure refrigerant gas. 12. The refrigerator according to claim 11, wherein the high-pressure refrigerant gas that supports the rotor core when starting the compressor uses refrigerant gas in a pressure tank that is stored separately. The high-pressure refrigerant gas that supports the rotor core during steady-state operation of the compressor uses the refrigerant gas discharged from the compressor as it is, and the refrigerant gas that functions as the working fluid of the static pressure bearing of the rotor core is an evaporator. A refrigerator characterized by being configured to return. 13. The refrigerator according to claim 11, wherein the high-pressure refrigerant gas for supporting the rotor core at the time of starting the compressor uses refrigerant gas in a pressure tank stored separately. The high-pressure refrigerant gas that supports the rotor core during normal operation of the compressor is obtained by compressing the saturated refrigerant gas of the condenser with another gas compressor, and also functions as a working fluid for the static pressure bearing of the rotor core. A refrigerator configured to return the cooled refrigerant gas to the condenser. 14. The refrigerator according to claim 11, wherein the high-pressure refrigerant gas that supports the rotor core when starting the compressor uses refrigerant gas in a pressure tank that has been separately stored. The high-pressure refrigerant gas that supports the rotor core during steady-state operation of the compressor is obtained by compressing the refrigerant gas from the evaporator with another gas compressor and functions as the working fluid of the static pressure bearing of the rotor core. A refrigerator configured to return the cooled refrigerant gas to the evaporator. 15. The refrigerator according to claim 11, wherein the high-pressure refrigerant gas that supports the rotor core when starting the compressor uses refrigerant gas in a pressure tank that is separately stored. The high-pressure refrigerant gas that supports the rotor core during steady-state operation of the compressor is obtained by compressing the refrigerant gas of the evaporator with another gas compressor, and also functions as the working fluid of the static pressure bearing of the rotor core. A refrigerator configured to return refrigerant gas to a condenser. 16. A refrigerant gas sucked into the suction part is compressed and discharged to a condenser as a high-temperature and high-pressure refrigerant gas, and lubricating oil stored in an oil tank in the casing is driven by an oil pump to drive a bearing portion or the like. In the compressor configured to supply the lubricated portion, a jet pump that uses lubricating oil pumped by an oil pump as a driving fluid is provided between the refrigerant gas suction portion and the oil tank, and the jet pump is driven by the jet pump. A compressor characterized in that the lubricating oil present in the suction section is collected in the oil tank. 17. A high-temperature and high-pressure refrigerant gas compressed by a compressor is condensed by exchanging heat with a cooling liquid in a condenser, and the high-pressure refrigerant liquid thus condensed is exchanged with liquid by an evaporator. It is configured to evaporate and return to the compressor as a low-pressure refrigerant gas, and in the compressor, lubricating oil stored in an oil tank in the casing is driven by an oil pump to a lubricating portion such as a bearing portion. In the refrigerator configured to supply, a jet pump that uses lubricating oil pumped by an oil pump as a drive fluid is provided between a suction portion of the refrigerant gas in the compressor and the oil tank, and the jet pump drives the A refrigerator configured to collect lubricating oil present in a suction portion into the oil tank. 18. The refrigerating machine operating method according to claim 17, wherein after the refrigerating operation of the refrigerating machine is stopped, only the operation of the oil pump is continued for a certain period of time. How to operate the machine.