JPH0419398A - Turbo compressor for heat recovery - Google Patents

Abstract

PURPOSE:To carry out a low head operation effectively at the time of extracting cold water by providing a second compression chamber like a snail shell on a radially inward part of a first compression chamber like a snail shell communicated with a diffuser, and providing a switch means for changing ove the diffuser to eigher of the compression chambers. CONSTITUTION:In a turbo compressor main body l, an impeller 6 is rotatably supported to a center of a housing 2 through a gear mount assembling body 4 interlocking with a motor 3, while a duffuser 7 is faced to the outlet side of the impeller 6. A first compression chamber 9 like a snail shell which is communicated with the duffuser 7 is provided on a radially outer part of the diffuser 7. At the time of lowering a head, a second compression chamber 25 like a snail shel is provided on a radially inward part of the first compression chamber 9 so as to shift iso-efficiency line distribution of the turbo compressor main body l itself to the lower head side by shortening the length of the diffuser 7. The second compression chamber 25 is communicated with the diffuser 7 at its intermediate part, while a switch means 26 for changing over the diffuser 7 to either of the compression chambers 9, 25.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a turbo compressor for heat recovery that allows extraction of cold water and hot water.

(Prior Art) Conventionally, heat recovery centrifugal chillers that enable extraction of cold water and hot water have been described, for example, in catalogs (Daikin Industries, Ltd.,
This is already known as described in the technical data published in June 1988).

The refrigerator described in this catalog has a condenser (B) connected to the discharge side of the turbo compressor (A), as shown in Figure 9.
A hot water pipe (D) and an evaporator (
A cold water pipe (G) is provided to exchange heat with the evaporator (E), take out cold water from the evaporator (E), and supply it to the cooling air conditioner (F), so that cold water and hot water can be taken out. Furthermore, (H
) is a cooling tower.

(Problems to be Solved by the Invention) Generally, the iso-efficiency line distribution of the turbo compressor (A) is, for example,
If the insulating head H (iffl/kg) is expressed on the vertical axis and the air volume (discharge amount) Q (+//-m) is expressed on the horizontal axis, the sixth
As shown by the solid line in the figure, if you look at it schematically, the air volume Q
The efficiency tends to deteriorate as the heat insulating head and the heat insulating head H both decrease. In addition, in the same figure, the numerical values attached to the iso-efficiency lines indicate percentages (%), and the range in which the maximum efficiency is exhibited is expressed as 100.
) indicate the surging lines when cold water is taken out.

By the way, the compressor (A) that performs heat recovery operation that enables cold water and hot water to be taken out is generally operated at high head when hot water is taken out and at low head when cold water is taken out. The head H2 is designed so that it can be operated near the high efficiency range as shown in FIG. Further, the above-mentioned iso-efficiency line distribution is determined by, for example, the size and shape of the diffuser and impeller of the turbo compressor (A), and the
A) It is unique.

Therefore, if the design is such that high efficiency operation can be achieved with a high head H2 when taking out hot water as described above, when taking out cold water, it will be operated at a low head operation, that is, a low head H1 in Fig. 6. There was a problem that the efficiency was lower than that when operating at H2.

In order to solve the above problems, the present invention shortens the length of the diffuser of the turbo compressor to shift the isoefficiency line distribution of the turbo compressor to the low head side, thereby achieving high head operation during hot water extraction. An object of the present invention is to provide a turbo compressor for heat recovery that is capable of efficiently performing low-head operation near the maximum efficiency range when cold water is taken out while efficiently performing the same operation near the maximum efficiency range.

(Means for Solving the Problems) In order to achieve the above object, a second bean-like compression chamber (25) is provided inward in the radial direction of the first cochlear-like compression chamber (9) communicating with the diffuser part (7). is provided, and the second M medium compression chamber (2
5) is communicated with the middle of the diffuser part (9), and the diffuser part (9) is connected to the first and second M
Switching means for switching to one of the medium compression chambers (9) and (25)
26).

(Function) When taking out hot water, the switching means (26) causes the diffuser section (7) to communicate only with the first cow-shaped compression chamber (9), and the entire length of the diffuser section (7) is used. , an equal efficiency distribution is obtained as shown by the solid line in FIG. 6, and operation can be performed near the maximum efficiency range at high heads.

Further, when taking out cold water, the switching means (26) switches the diffuser section (7) into the second annular compression chamber (25).
Switch so that it communicates only with the diffuser section (
7) By shortening the length, the maximum efficiency range can be reduced to the 6th
It is possible to shift from the position shown by the solid line in the figure to the position shown by the dotted line, that is, to the low head side, and it is possible to operate near the maximum efficiency range even with a low head. Moreover, as will be described later, when the length of the diffuser section (7) is shortened, the diffuser efficiency is improved, so the diffuser efficiency is not reduced at low head, but on the contrary, while improving the diffuser efficiency, Able to operate in maximum efficiency range.

(Example) The basic structure of the turbo compressor main body (1) shown in FIG.
) via the gear mount assembly (4) linked to the hub (
5) is rotatably supported, and a diffuser part (7) is made to face the outlet side of this impeller (6). In addition, the diffuser part (
A first cochlear compression chamber (9) communicating with the diffuser section (7) and the discharge pipe (8) is provided on the radially outer side of the impeller (6), and a first cochlear compression chamber (9) is provided on the radially outer side of the impeller (6). A guide vane (10) is disposed in the vane (10).
By adjusting the opening degree of the diffuser section (
7) to enable capacity controlled operation of the compressor main body (1). In addition, in the same figure, (1
1) A ring gear coupling, (12) an oil pump, (13) an oil pipe, and (14) a motor for adjusting the guide vane (10).

Further, as shown in FIG. 2, the turbo compressor main body (1) is equipped with a condenser (15) and an evaporator (16) to control the refrigerant discharged from the discharge pipe (8). , as shown by the dotted arrows, condensing in the condenser (15) and evaporating in the evaporator (16) to form a refrigeration cycle, thereby forming a heat recovery refrigerator.

That is, the condenser (15) connected to the discharge pipe (8)
has a cooling tower (17), and this condenser (
A cooling water circulation system (18) that supplies cooling water to a heating air conditioner (15) and a heating air conditioner (
The evaporator (16) is connected to a hot water circulation system (20) that supplies the water to the evaporator (19), and a cold water circulation system that extracts cold water from the evaporator (16) and supplies it to the cooling air conditioner (21). (22) is connected so that cold or hot water can be taken out. In addition, (23) is the heating air conditioner (
19) is a three-way valve that adjusts the amount of water supplied to the cooling tower (17) according to the temperature of the hot water supplied to the cooling tower (17);
(24) is a pump installed in each circulation system (18), (20), and (22), which flows each water in the direction of the solid line arrow.

Therefore, in the present invention, by shortening the length of the diffuser section (7) at the time of low head, in order to shift the original iso-efficiency line distribution of the turbo compressor body (1) to the low head side, A second dovetail compression chamber (
25) to connect the second cochlear compression chamber (25) to the middle of the diffuser section (7), and connect the diffuser section (7) to the first and second cochlear compression chambers (
7) A switching means (26) for switching to one of (25) is provided.

That is, as shown enlarged in FIGS. 3 and 4, the first
A second cochlear compression chamber (25) is provided radially inward of the cochlear compression chamber (9) by a partition wall (27), and a second cochlear compression chamber (25) is provided in the middle of the diffuser section (7) through an annular opening (28). communicate with. Further, an annular groove (2) is provided in the partition wall (27).
9) and a plurality of through holes (30) opening at the bottom of the annular groove (29). Further, in the through hole (30), for example, a pinion and a rack (
The diffuser portion (31) of each rod (31) is inserted through a plurality of openings/nodes (31) that are slidable in the axial direction via a drive device (not shown), hydraulic pressure/cylinder, etc.
7) Connect the side end to the cylindrical part (
32). This annular switching valve (34), as shown in FIG. Section 7 from the lid part (33) that closes 28)
The annular switching valve (34), a plurality of rods (31) connected to the switching valve (34), and a driving source thereof constitute the switching means (26). .

A tapered portion (35) is provided at the tip of the lid (33) to enhance the adhesion of the lid (33) to the periphery of the opening (28).

Next, the operation of the heat recovery turbo compressor configured as above will be explained.

When taking out hot water to supply hot water to the heating air conditioner (19) installed in the hot water circulation system (20), as shown in FIG. 3
2) is accommodated in the annular groove (29), the opening (28) is closed by the lid (33), and the diffuser part (7) is placed only in the first dovetail compression chamber (9). communicate with. At this time, the original uniform efficiency distribution of the compressor main body (1) as shown by the solid line in FIG. 6 is obtained, and the compressor can be operated near the maximum efficiency at the high head H2.

On the other hand, when taking out cold water, the switching valve (34) is moved to the right in FIGS. 3 and 4 via the rod (31), and as shown in FIG. (2
5), and the first opening (28) of the diffuser part (7) is opened in the cylindrical part (32).
Communication to the cochlear compression chamber (9) is cut off, and the diffuser portion (7) is communicated only to the second cochlear compression chamber (25). At this time, the gas sent from the impeller (6) enters the second cochlear compression chamber (25) from the diffuser section (7) via the opening (28). Therefore, the length of the flow path in the diffuser section (7) is shorter than that shown in FIG. 3, and an equal efficiency distribution as shown by the dotted line in FIG. 6 is obtained. Since this distribution shifts to the low head side from the constant efficiency distribution shown by the solid line, operation near the maximum efficiency range is possible in the low head H2.

Next, when the diffuser part (7) is communicated with the first cochlear compression chamber (9) and when it is communicated with the second cochlear compression chamber (25), that is, the switching valve ( 34)
The change in diffuser efficiency with respect to the operating head when the position is shown in Figure 3 and the position shown in Figure 4 is measured by setting the vane opening to 80%, for example, and the diffuser efficiency is plotted on the vertical axis. is shown in FIGS. 7 and 8, in which the horizontal axis represents the head. The diffuser efficiency (CR,) in Fig. 7 is determined by p, -pCR, = ρ・■2/2, and the diffuser efficiency (C
R2) is the pressure on the inlet side of the diffuser section (7), and P is the pressure on the inlet side of the diffuser section (7). The compression chamber (
9), and P7 is the pressure at the entrance to the compression chamber (25) when the diffuser part (7) is communicated with the second cow-shaped compression chamber (25). be. Further, ■ indicates speed, and ρ indicates density.

Comparing Figures 7 and 8, the diffuser section (
7) When the length is short, that is, when the switching valve (34) is in the position shown in FIG. 4, the diffuser efficiency curve is as follows: When the length of the diffuser part (7) is long,
That is, although the change is large compared to when the switching valve (34) is in the position shown in FIG. 3, the head showing the maximum value of the diffuser efficiency is lower than that in FIG. The maximum value in FIG. 7 is large.

Therefore, by switching the switching valve (34) to make the diffuser part (7) communicate only with the second cochlear compression chamber (25) and shortening the length of the diffuser part (7), the cold water When the head of take-out is low, the maximum efficiency line distribution can be shifted from the position shown by the solid line in Fig. 6 to the position shown by the dotted line, that is, to the low head side, and the differential user This allows the diffuser to operate in its maximum efficiency range without reducing efficiency, or even increasing diffuser efficiency.

In the above embodiment, the annular switching valve (34) having an angular cross section and a plurality of rods (31) movable in the axial direction are used as the switching means (26). valve(
It is not limited to 34) and ro)' (31).

(Effects of the Invention) As explained above, the present invention provides a diffuser section (7
) radially inwardly of the first bull-shaped compression chamber (9) communicating with the
A second silk cow-shaped compression chamber (25) is provided, and the second silk cow-shaped compression chamber (25) is communicated with the middle of the diffuser section (7), and the diffuser section (7) is connected to the first and second silk cow-shaped compression chambers (25). Since a switching means (26) is provided for switching to one of the first silk cow-shaped compression chambers (9) and (25), the second annular compression of the diffuser part (7) is performed by the switching means (26) when cold water is taken out. By communicating only with the chamber (25), it is possible to operate with a shortened length of the diffuser section (7). Therefore, the maximum efficiency distribution can be shifted from the position shown by the solid line in FIG. 6 to the position shown by the dotted line, that is, toward the low head side, and operation can be performed near the maximum efficiency range even with a low head.

Moreover, if the length of the diffuser section (7) is shortened, the diffuser efficiency will be improved, so the diffuser efficiency will not be reduced at low head, but on the contrary, the diffuser efficiency will be improved and the maximum efficiency range will be achieved. It is possible to drive.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the main body of the turbo compressor for heat recovery of the present invention, Fig. 2 is a perspective view of the same compressor, Fig. 6 is a right view of equal efficiency lines, and Figs. 7 and 8 are FIG. 9 is a characteristic diagram showing the relationship between the diffuser efficiency and the head, and FIG. 9 is a piping system diagram of a heat recovery refrigerator illustrating a conventional example. (7) Diffuser part (9) Φ First cochlear compression chamber (25) Second cochlear compression chamber (26) Switching means 3 Figure 4 Figure 4 5 Figure 6 Figure 8 Figure 9

Claims (1)

[Claims] 1) A turbo compressor for heat recovery that enables extraction of cold water and hot water, with a second cochlear compression chamber radially inward of the first cochlear compression chamber (9) communicating with the diffuser part (7). (25), and the second cochlear compression chamber (25) is provided.
switching means (5) communicating with the middle of the diffuser section (9) and switching the diffuser section (9) to one of the first and second cochlear compression chambers (9) and (25);
26) A turbo compressor for heat recovery, characterized in that it is provided with: