JP2011117648A - Turbo refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbo refrigerator capable of suppressing decline in efficiency by reducing pressure loss of a steam refrigerant by connecting piping, of reducing the size to save a space and of smoothly guiding the steam refrigerant to a condenser by a simple configuration which can be easily manufactured and having a centrifugal compressor. <P>SOLUTION: In the turbo refrigerator, a gas-phase refrigerant (R1) from an evaporator (1) is compressed by the turbo compressor (2) and is condensed by the condenser (4) and by evaporating an obtained liquid-phase refrigerant (R3) by the evaporator (1), a cooling target (W1) is cooled by the evaporation heat. At least one of the evaporator (1) and the condenser (4) is a straight pipe type including a plurality of linear tubes (C1-C4, D1-D4) forming the refrigerant piping, and at least one portion is arranged adjacent to the compressor (2) in a superposed position viewed from the axial direction of the compressor (2). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In the present invention, a gas phase refrigerant is compressed by a turbo compressor, condensed by a condenser, and the obtained liquid phase refrigerant is evaporated by an evaporator, whereby a cooling object is cooled by the heat of vaporization. It relates to a refrigerator.

  In recent years, a turbo chiller of this type has been proposed that uses water as a refrigerant instead of greenhouse gases such as chlorofluorocarbon for environmental measures. In such a turbo refrigerator, water having a higher boiling point than that of chlorofluorocarbon is evaporated under a low pressure, so that the density of the refrigerant decreases and the volume flow rate increases, so that the compressor becomes large. On the other hand, since water has better thermal conductivity than Freon, heat exchangers such as condensers and evaporators are not as large as compressors. Therefore, although the apparatus is enlarged, the compressor, the condenser and the evaporator are not enlarged at the same ratio, but only the compressor is larger than the other components. When a compressor, heat exchanger, which is a general structure of a Freon turbo chiller, is used as a separate element, and a structure in which pipes are connected to each other is applied to water refrigerant, only the compressor becomes larger and the centrifugal blade A large dead space is generated around the car. Moreover, in order to minimize the size of the apparatus as much as possible, the piping is made as small as possible, so the flow rate of the refrigerant increases, pressure loss occurs, and the performance of the refrigerator decreases.

  As a countermeasure against this, the impellers of the two-stage centrifugal compressor are arranged back to back, and the refrigerant that flows out radially is collected by the scroll and connected to the evaporator and condenser by piping, and continues to the impeller. A plurality of diffuser ducts are provided, and first-stage diffuser ducts and second-stage diffuser ducts are alternately arranged in the circumferential direction (see Patent Document 1).

Japanese Patent No. 4191477

  However, the compressor of Patent Document 1 has a very complicated configuration and is expensive to manufacture. Also, a large dead space remains around the centrifugal impeller.

  The present invention simplifies the structure by reducing the number of connection pipes for the vapor refrigerant, and reduces the pressure loss caused by the connection pipes to suppress the reduction in efficiency, and can be reduced in size to save space. The purpose is to provide.

  In order to achieve the above object, a turbo refrigerator according to the present invention compresses a gas-phase refrigerant from an evaporator with a centrifugal turbo compressor, condenses it with a condenser, and converts the obtained liquid-phase refrigerant into A turbo chiller that cools an object to be cooled with the heat of vaporization by evaporating with the evaporator, wherein at least one of the evaporator and the condenser has a plurality of linear tubes forming a refrigerant pipe. It has a straight pipe shape and is disposed at a position where at least a part thereof is adjacent to the compressor and overlaps when viewed from the axial direction. Here, “adjacent to the compressor” means a state in which they are close to each other in the axial direction and the radial direction, and preferably a part or all of them are superposed with the compressor as viewed from the radial direction.

  According to this turbo chiller, at least one of the evaporator and the condenser is arranged at a position adjacent to the compressor and superposed when viewed from the axial direction of the compressor, that is, in the vicinity of the periphery of the compressor. Therefore, the supply of the vapor refrigerant from the evaporator to the impeller of the compressor or the supply of the vapor refrigerant from the compressor to the condenser can be performed directly without using a long connecting pipe, and Since it can be performed smoothly, connection piping can be omitted. Thereby, while simplifying a structure, since the pressure loss which had arisen with the connection piping is lose | eliminated, the efficiency fall of a refrigerator can be suppressed. In addition, since the evaporator or / and the condenser are provided using the space around the compressor, which has been a large dead space in the past, the entire refrigerator can be reduced in size by saving space. . Moreover, since the evaporator and / or condenser is a straight tube type, it is easier to manufacture than the case of using a circular tube corresponding to the external shape of the compressor, and replacement and cleaning of the tube are required for maintenance. There is an advantage that can be easily done.

  In the present invention, the outlet of the compressor is preferably a quadrangle when viewed from the axial direction, and the straight pipe-shaped condenser is preferably polymerized with the compressor when viewed from the axial direction and the radial direction. According to this configuration, by arranging the condenser parallel to the square outlet side of the compressor, the vapor refrigerant flowing out from the outlet of the compressor flows uniformly into the condenser, so the efficiency of the condenser Will improve. In addition, since the condenser is disposed at a position where it is overlapped with the compressor when viewed from both the axial direction and the radial direction, the condenser can be disposed by effectively utilizing the space around the compressor. Furthermore, since the vapor refrigerant flowing out from the impeller of the compressor can be directly supplied to the condenser without going through the scroll and the long connection pipe, both the scroll and the connection pipe provided in the existing turbo refrigerator As a result, the structure is simplified and pressure loss due to the scroll and the connecting piping is eliminated.

  In the present invention, the compressor is a back-to-back two-stage centrifugal type, and the straight pipe-shaped condenser is provided between an intermediate passage for introducing refrigerant from the front stage of the compressor to the rear stage of the compressor and the rear stage of the compressor. It is preferable that they are arranged. According to this configuration, the vapor refrigerant flowing radially from the rear stage of the compressor can be supplied to the condenser without traversing the intermediate passage.

  In a configuration using back-to-back two-stage centrifugal compressors, it is preferable that at least a part of the straight-tube evaporator is superposed with the compressor when viewed in the axial direction and the radial direction. According to this structure, an evaporator can be arrange | positioned using the space around a compressor effectively. In addition, since the vapor refrigerant flowing out of the evaporator can be directly and smoothly supplied to the compressor without going through the connecting pipe, the connecting pipe becomes unnecessary, resulting in a simplified structure and a pressure caused by the connecting pipe. Loss disappears.

  In a configuration using back-to-back two-stage centrifugal compressors, it is preferable that the evaporator and the condenser face each other in the axial direction across the diffusers at both stages of the compressor. According to this configuration, the evaporator and the condenser can be arranged in a balanced manner on both sides in the axial direction of the compressor, so that the turbo chiller has a compact configuration.

  In a configuration using back-to-back two-stage centrifugal compressors, it is preferable that an intermediate cooler for cooling the refrigerant guided from the front stage of the compressor to the rear stage of the compressor is disposed behind the condenser. According to this structure, the compression efficiency of a compressor improves by supplying the vapor refrigerant | coolant which was compressed in the front stage of a compressor and the temperature rose to the back stage of a compressor after cooling with an intermediate cooler. Preferably, the intercooler can also be concentric with the compressor, so that it can be arranged in a compact manner.

  In this invention, it is preferable that the said evaporator is arrange | positioned at one side of the axial direction of the said compressor, and the drive device which drives the said compressor is arrange | positioned at the other. According to this configuration, it is possible to prevent the adverse effect that the evaporator is heated by the heat generated by the drive unit.

  In the present invention, it is preferable that at least the evaporator, the compressor, and the condenser are housed in a housing. As described above, since the connection pipe can be omitted in the present invention, the evaporator, the compressor, and the condenser can be housed in the housing, resulting in a compact structure.

  According to the turbo chiller of the present invention, since at least one of the evaporator and the condenser is disposed adjacent to the compressor and in the vicinity of polymerization when viewed from the axial direction of the compressor, the compressor is compressed from the evaporator. The connection of the vapor refrigerant from the evaporator to the compressor can be performed directly and smoothly without the need for a long connection pipe to supply the vapor refrigerant to the compressor or from the compressor to the condenser. At least one of the piping, the scroll for collecting the vapor refrigerant, and the connection piping for guiding the collected vapor refrigerant to the condenser is unnecessary, and the efficiency reduction of the refrigerator can be suppressed. Further, since the evaporator or / and the condenser are provided by effectively using the space around the compressor, the entire refrigerator can be miniaturized by saving space. Moreover, since the evaporator and / or the condenser are straight pipes, they are easy to manufacture, and the tubes can be easily replaced and cleaned during maintenance.

It is a schematic block diagram which shows the operating principle of the turbo refrigerator which concerns on 1st Embodiment of this invention. It is a longitudinal cross-sectional view of a turbo refrigerator same as the above. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a perspective view which shows the condenser of the turbo refrigerator of FIG. It is a longitudinal section showing a turbo refrigerator concerning a 2nd embodiment of the present invention. It is a longitudinal cross-sectional view which shows the turbo refrigerator based on 3rd Embodiment of this invention. It is a perspective view which shows the condenser of the turbo refrigerator based on 4th Embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a turbo refrigerator according to a first embodiment of the present invention. In this embodiment, water is used as a liquid refrigerant. In this turbo chiller, the liquid refrigerant (water) R3 accumulated at the bottom of the evaporator 1 is guided to the spray pipe 42 through the pumping pipe 41 by driving the pump 39, and is transferred from the spray pipe 42 onto the heat transfer pipe 5. By evaporating while spraying, the heat of vaporization takes heat from the cooling target (hereinafter referred to as cold water) W1 flowing in the heat transfer tube 5. The low-pressure vapor refrigerant R1 is sucked and compressed by a turbo compressor 2 that is rotationally driven by a drive unit 3 such as an electric motor, so that the high-pressure vapor refrigerant R2 is sent to the condenser 4 . The vapor refrigerant R2 is dissipated in the waste heat object (hereinafter referred to as cooling water) W2 flowing in the cooling pipe 6 in the condenser 4 to become a liquid refrigerant R3, and then passes through the return pipe 43. It is supplied to the bottom of the evaporator 1.

  In this turbo chiller, water having a higher boiling point is used as a refrigerant compared with conventional refrigerant such as Freon, so the compressor 2 is, for example, 1/100 atm on the inflow side and the outflow side on the outflow side. Negative pressure operation is set at 1/10 atm. Therefore, since the density of the refrigerant decreases and the volume flow rate increases, the size of the refrigerant is increased as compared with a refrigerator using refrigerant such as Freon. The chilled water W1 in the heat transfer tube 5 is, for example, cooled from 12 ° C. to 7 ° C. by the evaporator 1 and sent out, and used for indoor cooling of buildings and the like. The cooling water W2 in the cooling pipe 6 takes heat from the vapor refrigerant R2 in the condenser 4, for example, and is sent to the cooling tower at a temperature of 32 ° C. to 37 ° C.

  In FIG. 2 which shows the longitudinal cross-sectional view of the said turbo refrigerator, the housing 8 used as an exterior body has the structure where the rectangular parallelepiped housing main body 9 was mounted on the base 10, and was fixed. Main components including the evaporator 1, the compressor 2 and the condenser 4 are accommodated in the housing 8, and the evaporator 1 and the condenser 4 are disposed on both sides in the horizontal axial direction S of the compressor 2. Each is arranged. Hereinafter, the left side in FIG. 2 is referred to as the front side, and the right side is referred to as the rear side.

  The compressor 2 is a two-stage centrifugal type in which a front compressor front stage 2F and a rear compressor rear stage 2R are arranged back to back, and the compressor front stage 2F includes a front stage impeller (impeller) 20, The compressor rear stage 2R is also composed of a rear stage impeller (impeller) 22 and a rear stage diffuser 23 arranged concentrically outward in the radial direction R. It is configured. The front casing 14 </ b> F of the compressor front stage 2 </ b> F and the rear casing 14 </ b> R of the compressor rear stage 2 </ b> R are supported on a support base 18 fixed to the center of the upper surface of the base 10. The compressor 2 is driven by a driving machine 3 composed of an electric motor directly connected to the rear end portion (right end portion in the figure) of the rotary shaft 11.

  The evaporator 1 and the condenser 4 are disposed adjacent to the compressor 2, and are opposed to each other in the axial direction S across the diffusers 21 and 23 of the front stage 2F and the rear stage 2R of the compressor 2. Both the evaporator 1 and the condenser 4 are straight pipes, and details of the straight pipe structure will be described later. The evaporator 1 has a lower evaporation unit 1L and an upper evaporation unit 1U, and these lower evaporation unit 1L and upper evaporation unit 1U are located at upper and lower positions near the radially outer side on the suction side, which has a small diameter in the compressor front stage 2F. They are arranged and supported by the front casing 14F of the compressor front stage 2F.

  The condenser 4 has a lower condensing unit 4L and an upper condensing unit 4U, and the lower condensing unit 4L and the upper condensing unit 4U are arranged in the upper and lower portions in the vicinity of the radially outer side on the suction side which has a small diameter in the rear stage 2R of the compressor. It is arranged at each position and is supported by the rear casing 14R of the compressor rear stage 2R. The liquid refrigerant R3 liquefied in the condenser 4 is supplied to the lower evaporation unit 1L of the evaporator 1 through the return pipe 31. The liquid refrigerant R3 in the lower evaporation unit 1L is supplied to the spray pipes 42 in the condensing units 1A and 1B through the pumping pipe 41 by driving the pump 39.

  The front end portion of the rotating shaft 11 is rotatably supported by the bearing 12 held by the front casing 14F via a plurality of front stays 13F. The electric motor 3 directly connected to the rear end portion of the rotary shaft 11 passes through a vertically extending rear end wall 17 and is supported by the rear casing 14R via a plurality of rear stage stays 13R.

  The vapor refrigerant R1 from the evaporator 1 receives the suction force generated by the compressor 2 and is sucked into the compressor front stage 2F. The front impeller 20 sucks the vapor refrigerant R1 from the evaporator 1 from the inlet 20i toward the right in FIG. 2 along the axial direction S of the rotary shaft 11, flows toward the outside of the radial direction R, The gas flows out from the outlet 20e in the radial direction. The vapor refrigerant R21 flowing out from the front stage impeller 20 flows out from the outlet 21e to the intermediate passage 24 through the front stage diffuser 21, and flows into the compressor rear stage 2R from the intermediate path 24.

  As shown in FIG. 3, which is a cross-sectional view taken along line III-III in FIG. 2, the outlet 21e of the front diffuser 21 forms a quadrangle (in this example, a square) when viewed from the axial direction R, and this outlet 21e A front half portion of a rectangular intermediate passage 24 is formed between a passage inner wall 16 formed into a square having the same dimensions as the bottom plate 9a of the housing body 9 and the three peripheral walls 9b. An intermediate wall 27 is attached between the rear end portion of the passage inner wall 16 and the inlet end portion of the rear casing 14R. The intermediate wall 27 and the rear end wall 17 form a rear half portion of the intermediate passage 24. ing. An intermediate cooler 28 is disposed between the intermediate wall 27 and the rear end wall 17. The vapor refrigerant R <b> 21 is cooled by the intermediate cooler 28 when passing through the intermediate passage 24.

  The vapor refrigerant R22 that has flowed out of the intercooler 28 is sucked from the inlet 22i of the rear-stage impeller 22 toward the left in the drawing along the axial direction S of the rotary shaft 11, and the diameter of the vapor refrigerant R22 from the outlet 22e on the outer periphery of the rear-stage impeller 22 It flows out in the direction R. The vapor refrigerant R2 flowing out from the rear stage impeller 22 flows out from an outlet 23e provided inside the passage inner wall 16 through the rear stage diffuser 23. As shown in FIG. 3, the outlet 23e is also a quadrangle when viewed from the axial direction S. The condenser 4 is arranged in a space 30 provided between the rear casing 14R, the passage inner wall 16 and the intermediate wall 27, and the passage inner wall so that the vapor refrigerant R2 exiting the outlet 23e flows into the condenser 4. 16 and an outlet passage 29 for the vapor refrigerant R2 is formed between the condensation units 4L and 4U. The lower condensation unit 4L and the upper condensation unit 4U of the condenser 4 are horizontally arranged so as to extend in parallel along the horizontal upper and lower sides of the outlet 23e.

  Thus, by arranging the condenser 4 in the space 30, the entire condenser 4 becomes a position where it is superposed on the compressor 2 when viewed from the axial direction S and the radial direction R. As shown in FIG. 3, the vapor refrigerant R2 is liquefied by the condenser 4 and the refrigerant R3 that has become liquid returns to the evaporator 1 through the return pipe 31 of FIG. 2 as described above. The return pipe 31 is disposed in the housing 8 and passes through the bottom plate 9 a of the housing body 9 and the base plate 10 a that forms the upper surface of the base 10, and communicates the condenser 4 and the evaporator 1. Note that the return pipe 31 may be disposed so as to pass outside the housing 8.

  As shown in FIG. 3, each of the lower condensing unit 4L and the upper condensing unit 4U constituting the condenser 4 has a straight pipe shape, and the lower condensing unit 4L is a pair of units arranged at predetermined intervals on the same horizontal plane. The lower cooling water headers 4L1 and 4L2 are connected, and a plurality of linear tubes 40 extending in the horizontal direction are connected therebetween. Similarly, in the upper condensing unit 4U, a pair of upper cooling water headers 4U1 and 4U2 are connected by a number of tubes 40 extending in the horizontal direction. Further, the lower cooling water header 4L1 and the upper cooling water header 4U1 on the left side of FIG. 3 are connected by two connecting tubes 32 and 33.

  As shown in FIG. 4, each of the lower condensing unit 4L and the upper condensing unit 4U constituting the condenser 4 is divided into four. That is, the insides of the four headers 4L1, 4L2, 4U1, 4U2 are partitioned into four spaces S1 to S4, respectively, and accordingly, the tube 40 is also a group of four tubes connected to the spaces S1 to S4. It is divided into C1 to C4. The two opposing spaces S2 and S1 in the upper and lower cooling water headers 4L1 and 4U1 on the left side of FIG. 4 are connected by the connecting tube 32, and the other two spaces S3 and S4 are connected by the connecting tube 33. Yes. . Further, a cooling water inflow pipe 34 and a cooling water outflow pipe 38 are connected to the two lower spaces S1 and S4 of the lower cooling water header 4L1 on the left side of FIG.

  In the condenser 4, the cooling water W2 flowing into the first space S1 of the lower cooling water header 4L1 on the left side of the lower condensing unit 4L of the condenser 4 from the cooling water inflow pipe 34 passes through the first tube group C1 on the right side. After flowing into the first space S1 of the lower cooling water header 4L2 and entering the second space S2 from the first space S1, it flows into the second space S2 of the lower cooling water header 4L1 through the second tube group C2. . The cooling water W2 in the second space S2 flows through the connecting pipe 32 into the first space S1 of the upper cooling water header 4U1 on the left side of the upper condensing unit 4U, and then passes through the first tube group C1 to the right side. It flows into the first space S1 of the upper cooling water header 4U2.

  The cooling water W2 flowing into the first space S1 of the upper cooling water header 4U2 returns from the second space S2 to the upper condensed water header 4U1 through the second tube group C2, and the second space S2 of the upper cooling water header 4U1. Enters the third space S3, passes through the third tube group C3, flows into the third space S4 of the upper cooling water header 4U2, and passes from the fourth space S4 through the fourth tube group C4 to the third cooling water header 4U1. Return to 4 space S4. The cooling water W2 further enters the third space S4 of the lower cooling water header 4L1 of the lower condensing unit 4L through the connection tube 33, and flows into the third space S4 of the lower cooling water header 4L2 through the third tube group C3. Further, after returning to the fourth space S4 of the lower cooling water header 4L1 through the fourth space S4 and the fourth tube group C4, the cooling water flows out from the cooling water outflow pipe 38. As described above, when the cooling water W2 sequentially flows through the tube groups C1 to C4, heat is taken from the vapor refrigerant R2 supplied from the compressor 2 in FIG. 2, and the vapor refrigerant R2 is changed to the liquid refrigerant R3.

  The evaporator 1 has a straight tube structure similar to the condenser 4, and each of the evaporation units 1L and 1U is connected by a number of tubes 50 extending horizontally between the headers at both ends, and between the upper and lower headers at one end. They are connected by connecting pipes 35 and 36. In addition, a part of the evaporator 1 except for the front part is also in a space 30A existing in a portion where polymerization is performed when viewed from the axial direction S and the radial direction R, and the compressor front stage 2F including the front stage impeller 20 and the front stage diffuser 21. Has been placed.

  In this embodiment, the evaporator 1 and the condenser 4 are divided into two parts. However, the evaporator 1 and the condenser 4 may be divided into four parts and arranged parallel to the left and right sides in addition to the rectangular upper and lower sides.

  In the above-described configuration, the condenser 4 shown in FIG. 2 is located outside the compressor rear stage 2R and overlaps with the compressor rear stage 2R when viewed from the axial direction S and the radial direction R, that is, the rear stage impeller 22 of the compressor rear stage 2R. Therefore, the vapor refrigerant R2 flowing out from the rear stage impeller 22 of the compressor 2 can be directly guided to the condenser 4 from the rear stage diffuser 23. Thereby, both the scroll for collecting the refrigerant R2 flowing out from the latter stage of the compressor of the conventional two-stage centrifugal compressor and the long connecting pipe for guiding the collected vapor refrigerant to the condenser become unnecessary. As a result, the structure is simplified, and the pressure loss that has occurred in the scroll and the connecting piping is eliminated, so that a reduction in efficiency of the refrigerator can be suppressed.

  In addition, since the position near the radially outer side of the rear impeller 22 in the rear stage 2R of the compressor is a large dead space in the conventional turbo refrigerator, by utilizing this place for the installation location of the condenser 4, By reducing the space, the entire refrigerator can be reduced in size. In particular, since this turbo refrigerator uses water having a high boiling point as a refrigerant, the compressor 2 having impellers 20 and 22 having a relatively large diameter is used because the density is reduced because of low pressure operation under negative pressure conditions. Since there is a large space on the outer side where the polymerization is seen from the axial direction S and the radial direction R, the large space is required for the rear stage 2R of the compressor composed of the rear stage impeller 22 and the rear stage diffuser 23. The condenser 4 can be easily installed by effectively using the space 30 formed.

  In this embodiment, the entire condenser 4 is superposed in the axial direction S and the radial direction R with respect to the compressor rear stage 2R including the rear stage impeller 2 and the rear stage diffuser 23. About superposition | polymerization, it is good also as an arrangement | positioning which superpose | polymerizes only a part other than the part of the condenser 4, for example, the axial direction rear part (right side of FIG. 2) of the condenser 4, with respect to 2R of compressor rear stages.

  Moreover, in this turbo refrigerator, a part excluding the front part of the evaporator 1 is also provided in a large space 30 </ b> A that exists in a portion where polymerization occurs when viewed from the compressor front stage 2 </ b> F and the axial direction S and radial direction R. Therefore, the evaporator 1 can be easily installed by effectively using the space 30A. Of course, you may arrange | position so that the whole evaporator 1 may superpose | polymerize seeing from the compressor front | former stage 2F from the axial direction S and radial direction R. FIG.

  Further, since the condenser 4 is disposed in a space 30 surrounded by the intermediate passage 24 connected to the outlet 21e of the compressor front stage 2F and the rear casing 14R of the compressor rear stage 2R, the condenser 4 is disposed rearward in the axial direction from the compressor rear stage 2R. The flowing out refrigerant refrigerant R2 can be supplied to the condenser 4 without crossing the intermediate passage 24. Accordingly, the outlet passage 29 connecting the compressor rear stage 2R and the condenser 4 is short and has a simple shape.

  In addition, since the vapor refrigerant R21, which has been compressed in the upstream stage 2F of the compressor and increased in temperature, is supplied to the downstream stage 2R of the compressor after being cooled by the intermediate cooler 28, the compression efficiency of the compressor 2 is improved. Furthermore, as described above, since scrolls and connecting pipes are not required, main components including the evaporator 1, the compressor 2 and the condenser 4 can be accommodated in the housing 8, resulting in a compact structure. . Moreover, the straight-tube condenser 4 and the evaporator 1 having the straight tubes 40 and 50 are easy to manufacture as compared with the case where the pipe is constituted by a plurality of circular tubes corresponding to the outer shape of the compressor. In addition to being inexpensive, there is an advantage that the tubes 40 and 50 can be easily replaced during maintenance.

  Further, as clearly shown in FIG. 2, the turbo chiller has a rectangular shape when viewed from the axial direction S with respect to the outlet 23e of the rear stage 2R of the compressor as the condenser 4 has a straight pipe shape. Since the lower condensing unit 4L and the upper condensing unit 4U are arranged in parallel with each other, the vapor refrigerant R2 flowing out from the rectangular outlet 23e is different from the case where the outlet of the rear stage 2R of the compressor is circular. Therefore, the heat dissipation of the vapor refrigerant R2 with respect to the cooling water W2 flowing in the tube 40 is efficiently performed.

  FIG. 5 shows a turbo chiller according to a second embodiment of the present invention, in which the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. This turbo refrigerator has a structure in which an opening of a rectangular parallelepiped housing main body 9A forming the housing 8A is sealed by a lid 45, and the impellers 20 and 22 of the compressor front stage 2F and the compression rear stage 2R are provided. A two-stage centrifugal compressor 49 provided in a series arrangement with the same orientation is provided. The evaporator 1 is disposed on the front side (right side in FIG. 5) of the compressor 49, and includes a straight pipe type lower evaporation unit 1L and an upper evaporation unit 1U. An electric motor 3 is disposed between the lower evaporation unit 1L and the upper evaporation unit 1U.

  The refrigerant vapor R21 that has passed through the front-stage diffuser 21 from the front-stage impeller 20 is guided to the inlet of the rear-stage impeller 22 through the crossover-shaped intermediate passage 51 that turns back at an angle of 180 °. The condenser 4 is arranged in a position near the outside in the radial direction of the rear stage impeller 22 of the rear stage 2R of the compressor, and at a position where both are superposed on the rear stage 2R of the compressor when viewed from the axial direction S and the radial direction R. The outlet 23e of the rear diffuser 23, that is, the outlet of the compressor 2, is also square when viewed from the axial direction S, and a straight pipe-shaped lower condensing unit 4L and upper condensing unit 4U are arranged in parallel with the upper and lower sides thereof. ing.

  Also with this configuration, the vapor refrigerant R2 flowing out from the rear impeller 22 can be directly supplied to the condenser 4 without going through the scroll and the long connection pipe, so that the pressure loss generated in the scroll and the connection pipe is eliminated. , It is possible to suppress the efficiency reduction of the refrigerator. Moreover, by providing the condenser 4 by effectively using the space around the rear impeller 22, it is possible to eliminate the dead space and save space, and to achieve downsizing of the entire refrigerator.

  In this series-arranged compressor 50, since the compressor front stage 2F and the compressor rear stage 2R are both facing forward, the intermediate passage 51 connecting the compressor front stage 2F and the compressor rear stage 2R, and the compressor rear stage The problem existing in the back-to-back two-stage centrifugal compressor that the passage connecting the 2R to the condenser 4 does not exist originally.

  FIG. 6 shows a turbo refrigerator according to a third embodiment of the present invention. This turbo refrigerator includes a single-stage centrifugal compressor 52 having only a single impeller 53 and a diffuser 57. The straight pipe type condenser 4 is disposed at a position where the compressor 52 is superposed on the outside in the radial direction of the impeller 53 of the compressor 52 when viewed from the axial direction S and the radial direction R. The straight-tube evaporator 1 is disposed on the front side of the compressor 52. Therefore, also in this turbo refrigerator, since the vapor refrigerant R2 can be directly supplied to the condenser 4 without going through the conventional scroll and connection pipe, the pressure loss generated in the scroll and the connection pipe is eliminated, and the refrigerator The efficiency drop can be suppressed. Further, by providing the condenser 4 using the space around the impeller 53, the dead space can be eliminated and the space can be saved, and the miniaturization of the entire refrigerator can be achieved.

  FIG. 7 shows a cylindrical condenser 58 used in the turbo refrigerator of the fourth embodiment of the present invention. The condenser 58 has a straight pipe shape in which a pair of cylindrical cooling water headers 58 </ b> A and 58 </ b> B are communicated by a plurality of linear tubes 59. By providing the condenser 58 so as to accommodate the latter stage of the compressor, the same effect as described in the first to third embodiments can be obtained. The evaporator can also have a cylindrical shape similar to this. By setting it as such a cylindrical shape, a housing can be made into the circular shape corresponding to the external shape of a compressor.

  In each of the above-described embodiments, the horizontal type in which the rotation shaft 11 of the compressors 2, 49, 52 is oriented in the horizontal direction is described as an example. However, the present invention is not limited to the compressors 2, 50, 52. The present invention can also be applied to a vertical type in which the rotating shaft 11 is oriented in the vertical direction. Further, the drive unit 3 that drives the compressors 2, 50, 52 may be provided outside the housing 8. A speed increaser (gear) may be interposed between the drive unit 3 and the compressors 2, 50, 52.

  The present invention is not limited to the contents shown in the above embodiments, and various additions, modifications, or deletions can be made without departing from the spirit of the present invention. It is included in the range.

DESCRIPTION OF SYMBOLS 1 Evaporator 2, 49, 52 Turbo compressor 2F Compressor front stage 2R Compressor rear stage 3 Electric motor (drive machine)
4,58 Condenser 8 Housing 24, 51 Intermediate passage 28 Intermediate cooler 29 Outlet 40, 50, 59 Tube R1, R2 Vapor refrigerant (gas phase refrigerant)
R3 Liquid refrigerant (liquid phase refrigerant)
W1 Cold water (cooling object)
S Axial direction R Radial direction

Claims (8)

The refrigerant in the gas phase from the evaporator is compressed by a centrifugal turbo compressor, condensed by a condenser, and the liquid phase refrigerant thus obtained is evaporated by the evaporator. A turbo refrigerator for cooling,
At least one of the evaporator and the condenser has a straight pipe shape having a plurality of straight tubes forming a refrigerant pipe, and at least a part thereof is adjacent to the compressor and viewed from the axial direction of the compressor. Turbo chillers that are placed in positions where they overlap.   2. The turbo refrigerator according to claim 1, wherein an outlet of the compressor is square when viewed from an axial direction, and the straight pipe condenser is superposed with the compressor when viewed from an axial direction and a radial direction.   3. The condenser of claim 2, wherein the compressor is a back-to-back two-stage centrifugal type, and the straight pipe type condenser is provided between an intermediate passage for introducing a refrigerant from the front stage of the compressor to the rear stage of the compressor and the rear stage of the compressor. The turbo refrigerator is arranged.   The turbo refrigerator according to any one of claims 1 to 3, wherein at least a part of the straight-tube evaporator is superposed with the compressor when viewed in the axial direction and the radial direction.   The turbo chiller according to claim 3, wherein the evaporator and the condenser face each other in the axial direction with the diffusers at both stages of the compressor interposed therebetween.   The turbo refrigerator according to claim 3, wherein an intermediate cooler for cooling the refrigerant guided from the front stage of the compressor to the rear stage of the compressor is disposed behind the condenser.   The turbo refrigerator according to any one of claims 1 to 6, wherein the evaporator is disposed on one side in an axial direction of the compressor, and a drive unit that drives the compressor is disposed on the other side.   The turbo refrigerator according to any one of claims 1 to 6, wherein at least the evaporator, the compressor, and the condenser are accommodated in a housing.

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