JPS60111094A - Centrifugal type vapor compressor - Google Patents

Abstract

PURPOSE:To prevent the generation of the compression sensible heat by direct cooling and prevent the erosion of vane wheels by forming, onto the vane wheels, coolant injection ports for jetting-out the coolant supplied from coolant feeding passages formed onto a rotary shaft, into the coolant flow passages formed between vanes of the vane wheels. CONSTITUTION:The coolant, e.g., water which is introduced into the coolant flow passages 37, 34,... between the vanes 36, 36,... of the vane wheels 11-15, passing through the coolant feeding passages 41, 42,... formed onto a rotary shaft 2, is jetted-out from the coolant injection ports 38, 38,.... The compression sensible heat of the steam in the coolant passages 37, 37,... is absorbed in the compression cycle of the vane wheels 11-15 by the vaporization latent heat of water, and compression work over the range starting from the start of compression cycle to the end is lightened. The water jetted-out from the coolant injection ports 38, 38,... is jetted-out into the coolant flow passages 37, 37,... at an angular speed corresponding to the angular speed of the vane wheels 11-15. Therefore, the relative speed for the vane wheels 11-15 is hardly generated, and collision with the vane wheels 11-15 hardly occurs, and erosion of the vane wheels is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of use by industrialists> The present invention relates to a centrifugal vapor compressor suitable for use in refrigeration cycles and heat pump cycles.

<Prior art> In the multi-stage centrifugal vapor compression analysis system, the suction pressure of the refrigerant is rapid, so the compression is performed adiabatically or during the refrigerant transfer from one stage to the next. The refrigerant vapor is cooled at , and the compression work is reduced by making it as close to isothermal compression as possible. ．． ! 2, which is commonly used to improve the coefficient of performance of heat pumps, etc.

Conventionally, this type of centrifugal vapor compression (for example, a diffuser downstream of the impeller or a damper in the crossover passage) was used to cool the refrigerant vapor indirectly; Is there something that has been designed to reduce the effect of 'F'? However, although such centrifugal vapor compressors are indirectly cooled by a cage 7) which requires a large heat exchange area, due to the space constraints in which they are installed, they are not susceptible to fire. It has the drawbacks of being unable to provide a large heat exchange area, having insufficient cooling effect, and having a complex structure.

In addition, by providing an intermediate cooling unit between both blades, which has a large heat exchange area separate from the casing,
There is a centrifugal vapor compressor that indirectly cools the refrigerant vapor within 1 minute.However, due to the presence of an intercooler, (This creates a large passage resistance, and the structure is complex, making it difficult to use)
It has the disadvantage of being up.

Therefore, recently, as a centrifugal vapor compressor that eliminates these drawbacks, refrigerant liquid is injected into the diffuser downstream of the impeller at the front stage. By completely evaporating the refrigerant liquid in the diffuser, transfer passage, and return passage, the refrigerant vapor can be directly and efficiently cooled by the latent heat of evaporation of the refrigerant liquid with a simple structure. A method has been proposed that reduces the compression work of the impeller and prevents the refrigerant liquid from colliding with the impeller, thereby preventing corrosion of the impeller. −
13540 (Publication No. 1).

However, in order to prevent erosion due to collision between the impeller and the refrigerant liquid, the centrifugal vapor compression system uses a diffuser to prevent the refrigerant vapor coming out from the refrigerant flow path between the blades. Since the refrigerant liquid is injected from the side wall (static 11-wall) of the impeller and is not injected into the refrigerant flow path of the impeller's input 1"I or the blade jp, the compression work of the preceding impeller is reduced. However, the disadvantage is that the compression work is only for the latter stage impeller, which is insufficient.

<Objective 1 of the Invention> Therefore, the object of this invention is to suppress the occurrence of compression by direct cooling from the beginning to the entire compression stroke of refrigerant vapor with a simple structure; Reduce compression to the minimum and improve coefficient of performance.
In addition, the objective is to provide a centrifugal vapor compression system that can prevent impeller erosion.

<Structure and operation of the invention> In order to achieve the object described above, the configuration of the centrifugal vapor compressor of the present invention is such that the impeller has a refrigerant liquid ejection system that ejects refrigerant liquid into the refrigerant flow path between the blades of the impeller. 21 is provided, and a refrigerant liquid 0 (oil supply path) for guiding the refrigerant liquid to the power distribution medium liquid jet 1 is provided on the rotating shaft for rotating the impeller.

The action of the centrifugal vapor compressor of the present invention is as follows: 1) The refrigerant liquid passes through the refrigerant liquid supply passage of the rotary shaft and flows from the refrigerant liquid jet port of the impeller into the refrigerant flow path between the blades. It is ejected at an angular velocity approximately equal to the angular velocity of the impeller, and therefore,
The relative velocity between the impeller and the refrigerant liquid is almost eliminated, and the refrigerant liquid collides with the impeller. This prevents erosion of the impeller, and prevents the refrigerant liquid in the refrigerant flow path from colliding with the impeller. Due to the latent heat of vaporization, the sensible heat of pressure 1 compression of the refrigerant vapor in the refrigerant flow path is absorbed during the compression stroke of the impeller, and the compression work is reduced throughout the safe from the beginning of the compression stroke.

<Example> Hereinafter, the present invention will be explained in detail with reference to the illustrated example.

Fig. 1 shows a 5fy centrifugal vapor compressor, in which 1 is a casing, 2 is a casing 1, a bearing box 31415 and a bearing 6.
'? , 8, a rotary shaft rotatably supported through ]1,
12. ]3.3'L, 15 is an impeller of each stage fixed to the rotating shaft 2, 17 is a steam suction port, 1.18 is a steam discharge port,
2L 2], 2], 2], 2] are diffusers at each stage,
22, 22, 22, 22゜22 is the crossing passage of each stage, 25
．． 25 is a refrigerant liquid supply port for supplying water C as a refrigerant liquid which also serves as the shaft 1-1 liquid.

- Impeller IL 12, 13, 14. As will be described later, there is a refrigerant between the blades 36, 36, 36°... 37+3'? +37. ...Refrigerant liquid jet 1 which spouts cooling liquid, for example water, into the interior] 38, 38
゜38,... will be provided. These refrigerant liquid jets D38°38.38. ... and the refrigerant liquid supply port 25.25 are the refrigerant liquid supply passage 41. It communicates through l12.

L distribution medium liquid spout 3 L 3 L J jl) H...
and refrigerant liquid supply passage 41. The detailed configuration of l12 is as shown in FIG. In other words, the refrigerant liquid is ejected IJ on the 1st surface of the hub 45 of the hub 45 of the
8a.

38a, ``・ is provided, and the blade 36 of the blade i1L 15 is provided.
．． :Hi.

Cold IIL liquid sprayed on the wing surface of... 1-13811, 38
1) ,... ;JF) C+
, 38c, - The refrigerant flow path 3'L between the blades 36, 3 (5° 36, 37.37...) is designed to eject the refrigerant liquid. 1- Distribution medium liquid jet IJ
38a, 3) ib, 38c, - is /% 7'
It communicates with the inner circumferential groove 4G of 4.5, and this inner circumferential groove 1
6, one end of the refrigerant liquid supply passage 42 branches into a 1'-shaped cross section and communicates with the other end. On the other hand, "1 refrigerant liquid supply passage 42
The other end is opened to the outer circumferential surface of a sealing 17 provided on the rotating shaft 2 with a cross-sectional shape of 'I', and the shaft moon chamber 4;
(Communicates with.Radius 1 of the above-mentioned sealing 47) 1
is the outermost refrigerant liquid jet L] Same as 38 a 1
The distance from the center of the g-axis 2, that is, the rotation radius of the refrigerant liquid jet [38a F), is set smaller, and the radius L is set to 1),
,D. The refrigerant liquid (water)
The refrigerant liquid is automatically ejected through the refrigerant liquid supply passage 42.
138a, 38a... are spouted out. In addition, in this embodiment, 138a is used for all refrigerant liquid jetting.
, 381) , the radius of rotation of 38c is 1 - diameter D1
1 and 2 Seal Rings 47
Both end faces of are sealed with mechanical seals 51°51.

The second axis chamber 48 communicates with the refrigerant liquid supply +125. Note that the other impellers 33°12, 13, and 14 also have the same configuration as ``-Kihanetun''5.

In the centrifugal vapor compression system with the above configuration, the water vapor sucked from the steam suction [117] shown in FIG.
3.2.13. ] 4. ] 5 to 51 and is discharged from the steam discharge 118.

In the above compression process, each blade J1 river 1,12°1,
E, J 4. IS wing:', G,:'+ 6.36.
Middle refrigerant flow path 3°7 HJ 71 t'l 71 ・
・Inner/refrigerant liquid supply passage, 11. ．． The water that passed through ``12'' spouted out the refrigerant liquid 1-13E+.

38 H38, and the latent heat of vaporization of this water causes the refrigerant channels 37, 37, 37 . The sensible heat of compression of water vapor in...
It is absorbed during the T-stroke, and the compression work is reduced from the beginning to the entire compression stroke. In addition, refrigerant liquid jet 1
The water ejected from the impellers 11, 12, 13. 1, 12. 13° 14, . 1
5, there is almost no relative velocity, so impeller 1
1. ]2. ]3. 14. The impellers 11, 12, 13°14, . 35 erosions are prevented.

Regarding the fifth stage impeller 15 whose operation is shown in FIG.
Explain more specifically. Other impeller] 1゜12.13
, 14.15.

In FIG. 2, the water supplied to the glazing chamber 48 through the refrigerant supply port 25 acts as a seal between the mechanical seal 51 and the seal ring 47, and also functions as a shaft sealing liquid. Further, the water passes through the refrigerant liquid supply passage 42 of the rotary shaft 2 and the plurality of refrigerant liquid jet ports 3 of the impeller 15.
8a, 38a.

-=: 38b, 381], -; 38c, 38c
, - has the same angular velocity as the angular velocity of Kazuhanetun 15,
Wings 36, 36, 36. ...Refrigerant flow path 37, 3 between? .

37. It is squirted inward. Then, the water vapor whose temperature has increased by 1 due to compression is transferred to the refrigerant flow path 3' due to the latent heat of vaporization of water. +37+.;)■,... and is cooled in the diffuser 2L 21, 21, and as a result, the compression work is reduced, and the maximum discharge temperature of the steam is lowered. In this way, the maximum discharge temperature of water vapor is lowered, allowing the use of cheaper materials for the compressor, and the thermal expansion is reduced, making the labyrinth seal gap and shroud gap smaller, allowing the steam to flow more efficiently. Internal leakage can be reduced, and the efficiency of the compressor can be further improved by reducing the compression work mentioned above. Furthermore, since the water jetted out from the refrigerant jets 38a + 38b + 38c has approximately the same angular velocity as the impeller 15,
There is no collision with the blades 3G of the impeller 15, and erosion thereof is prevented. Also, the blades 36.36 of the impeller 15
．． In order to spray water from the refrigerant liquid jets D38a, 38+], 38c into the refrigerant flow paths 37.3'7H between the refrigerant flow paths 37, 37. ...Additional mass will be added within..., and the main volume of water vapor at the outlet will be 1U)t.
will increase. Therefore, with respect to the inlet flow path of the impeller 15 with a constant cross-section, the outlet 1 flow path becomes as shown by the solid line in Fig. can be made larger than the original size, thus relaxing the two limitations of strength and machining.
The scope of application of centrifugal compressors will be expanded to those with small flow rates. In other words, centrifugal compression (the lower limit of the flow rate can be expanded downward based on the comparative rotation speed. Also, the refrigerant liquid jet ports 38a, 381).

The rotation radius of 38c is all the radius D1 of the seal ring 47.
Since the refrigerant liquid is larger, water is smoothly ejected from all refrigerant liquid ejections D38a, 38b, and 38c due to the pump action due to the difference in centrifugal force, without providing a separate pressure feeding means. However, if the rotation radius D2 of the outermost refrigerant liquid jet port 38a is larger than the radius D1 of the seal ring 47, water can be ejected from all the refrigerant liquid jet ports. Furthermore, in this embodiment, the water as the refrigerant liquid also serves as the shaft sealing liquid, so the structure is simple.

Next, the characteristics when the centrifugal vapor compressor of the present invention is used in a heat pump are shown in the temperature-entropy diagram of FIG. 3 in comparison with the characteristics of a conventional centrifugal vapor compressor.

In FIG. 3, CR is the critical point, CT 1. is the condensation temperature, ET is the evaporation temperature, and the curves CR-E-E2-E, -G are
In the saturated liquid line 1 curve CI, -D-D, -D, -A are saturated vapor lines, and the evaporation temperature of the 2 saturated vapor lines is the saturated vapor line of the refrigerant used in the centrifugal vapor compressor of the invention. Refrigerants such as water, Freon R-11. Freon I Dog - 12,70 Freon I Dog 13. Freon R-22,
It must be something like carbon dioxide whose wetness decreases when compressed! A refrigerant such as Freon R-113, which increases iH'))l, can be used in the centrifugal vapor compression method of the present invention.

In addition, curve 1"lΣ-1)-133-B, curve E2-1
)2-B2 and curve E, -D, -1'3. are respectively,
They are isobars, and the curve CI < -C1 is -03° at curve C1. Curve C11-C2 and curve CR-C are equal to 13 and 2, respectively.
It is a strength line.

And the cycle diagram A-B-D shown in Fig. 3
-M -G -A shows the cycle of a heat pump using an adiabatic single-stage centrifugal compression chamber without conventional cooling, in which the refrigerant extracts the amount of heat QET from the low temperature source while changing from state G to state G. , is adiabatically compressed while moving from state Δ to state B, and releases heat (QEI×10B) to the high temperature source while moving from state B to state M via state 1]. Here, the amount of heat B corresponds to the amount of work in the cycle A-B-D-M-G, that is, the area surrounded by this cycle diagram. Therefore, the coefficient of performance COI' of this heat pump is defined as QEI COI"=-+].

Cycle diagram A-81-D, - indicated by @ in Figure 3
82-B2-133-D-M-G-A uses a conventional three-stage centrifugal vapor compressor that injects refrigerant liquid into a diffuser downstream of the impeller.

As can be seen from Fig. 3, the heat ffi and QFT drawn from the low temperature source are the same as in the direct cycle (2). in this case,
The refrigerant is compressed as it moves from state A to B1, cooled as it moves from state [31 to I-), and similarly compressed as it moves from state I) to B2;
During the transition from state F3° to 1)2, it is cooled and the state l)2
The material is compressed as it moves to the frame 33. In the case of this cycle @, it can be seen from Figure 3 that the compression work is smaller than that of cycle ■, and the coefficient of performance COp is lower than that of cycle ■.
I know it will be better than that.

In addition, cycle diagrams 1 to -C, -D, -C7 shown in ■
l) r, -C:,1. ) IVI-GA uses the centrifugal vapor compressor of this invention that performs direct cooling with three-stage pressure cut-off, and the refrigerant in state A becomes equivalent to state C1 with humidity Xl by injection of refrigerant liquid. , state C1 to 1) 1
While moving to the next stage, the pressure is increased, the temperature rises by 1, and the humidity reaches a slightly saturated state, and the same process is repeated in 8 steps.

As can be seen from FIG. 3, in the case of this zaikunori, the amount of compression work is reduced compared to the case of cycle (2), and Ik and performance coefficient C (month) are improved.

In addition, the cycle diagram shown in ■A-C-D-M-G
A shows a case where a centrifugal vapor compression system is used for direct cooling with one-stage compression of the present invention.
During the transition from to D, it is compressed, the temperature decreases, the humidity decreases, and it becomes saturated at the same temperature.

As is clear from Figure 3, this cycle diagram shows that the amount of work is reduced compared to cycle 0, and the coefficient of performance C0F) is increasing.
- to do.

The maximum discharge temperatures of each of the centrifugal vapor compressors described in Items 1) (■, ■; ■, ■) are shown at points B, B3 and 1) in FIG. Also, from Fig. 4, it can be seen that the cycles using the centrifugal vapor compressor of this invention (■, I understand.

In addition, from Fig. 5, the centrifugal vapor compression (Size 2 of the heat pump using the 戊) of this invention @, ■ is much more than that of the conventional heat pump cycle when the conventional B 1 pump cycle ■ is used as a standard. It can be seen that there is a high rate of increase in the coefficient of performance.

FIG. 6 shows an embodiment of the pond according to the present invention, and this centrifugal vapor compressor has a narrow end 42a of the refrigerant liquid supply passage 12 which is open to the axis of the rotating shaft 2. By guiding the refrigerant liquid into the refrigerant liquid supply passage 42 from the end 42a, the centrifugal force proportional to the radius of rotation of the refrigerant liquid jets ID38a, 3811, 38c can be utilized to the maximum to increase the pumping action on the refrigerant liquid. It is. In this embodiment, mineral oil is supplied to the shaft sealing chamber 48.

Further, the refrigerant liquid jetting port may be formed of a porous material not limited to the above-mentioned embodiment, so that the refrigerant liquid is atomized and jetted. Further, the centrifugal vapor compressor of this invention has one stage,
1゜〈Effects of the Invention〉 Regardless of the multistage type, as is clear from the above explanation, the centrifugal vapor compression system of the present invention (the holes are formed in the impeller to eject the refrigerant liquid into the refrigerant flow path between the blades) 1 for the liquid jet, and a refrigerant liquid supply passage that guides the refrigerant liquid to the refrigerant liquid jet 1'' on the rotating shaft that rotates the impeller described in -. The refrigerant is ejected into the flow path at the same angular velocity, and the sensible heat of compression of the refrigerant vapor is directly absorbed by the latent heat of vaporization of the refrigerant liquid. Overall, direct cooling), 11 can suppress the occurrence of obvious compression,
Therefore, it is possible to improve the coefficient of performance of heat pumps and the like by reducing the compression work to a minimum level, and furthermore, it is possible to prevent erosion of the impeller.

In addition, since the centrifugal vapor compressor of the present invention is constructed as described above, it can effectively cool the refrigerant vapor and lower the maximum discharge temperature of the vapor, thereby reducing the cost of the 41 material. In addition to being able to be constructed using
By reducing the labyrinth seal gap and the shroud gap, internal leakage of steam can be reduced, and the efficiency of the compressor 11 can be further improved by reducing the compression work described above.

In addition, since the centrifugal vapor compression method of the present invention (the amount of refrigerant liquid added to the refrigerant vapor in the refrigerant flow path) exerts a force of 1-
One flow path is heated compared to the conventional one, so the range of application of centrifugal vapor compression can be expanded to small if and three volumes, and the refrigerant liquid is Since the refrigerant liquid is ejected from the refrigerant, the centrifugal force of the blade iJt can be used to automatically eject the refrigerant liquid.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the main part of FIG. 1, FIG. 3 is a temperature-entropy diagram, and FIG.
Figure 1 is a characteristic diagram showing the maximum discharge temperature depending on the condensing temperature.
FIG. 5 is a characteristic diagram showing the rate of increase in the coefficient of performance depending on the temperature of coagulation, and FIG. 6 is an explanatory diagram of the main parts of the example of the plate. 1...Casing,...Rotating shaft, ]1. +2.13
．． 1□1.15... impeller, 3 (3... wing, 3'?
...refrigerant flow, path, 30,3 da, 3 Elf),
3 i3c ”'Refrigerant liquid jet 1,・11.・12・・
·cold! +! /J liquid supply passage. Patent applicant Kobe Steel, Ltd.

Claims (1)

[Claims] (1) Centrifugal vapor compression in which an impeller is rotated by a rotating shaft within a casing (in some cases, 1. impeller fil)
a refrigerant liquid jetting port provided at the rotary shaft and spouting the refrigerant liquid into the refrigerant flow path between the blades of the impeller;
A centrifugal vapor compression method characterized by having (iii) a refrigerant liquid supply passage that guides the refrigerant liquid to the refrigerant liquid spout 1.