JPH07109992A - Number control type feed water pump unit - Google Patents

Abstract

PURPOSE:To obtain a plurality of kinds of flow rate patterns in a pump unit which control the number of operated pumps so as to obtain constant discharge pressure irrespective of a feed wafer amount by providing the pumps having different flow rates by two, totally four. CONSTITUTION:Four pumps 1A, 1A; 1B, 1B are parallelly arranged. The pumps 1A and 1B show a flow rate ratio 1.4 to 1.6. The pumps 1A and 1B thus having different flow rates are arranged by two, totally four for securing a required amount of water. In addition, the number of the operated pumps are regulated so as to obtain constant discharge pressure. Suction sides of the pumps 1A and 1B are connected to a suction header pipe 16 having a fluid element 2, respectively through partition valves V1 to V4. The discharge sides are connected to a discharge header pipe 17 having a negative pressure generating device 8, respectively through check valves V5 to V8 and partition valves V9 to V12. Eight flow rate patterns are realized without repetition accordingly, and operation can be carried out according to a water supply amount without wastefulness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply pump unit, and more particularly to a unit-controlled water supply pump unit that reduces power consumption and is integrated into a small panel type.

[0002]

2. Description of the Related Art Conventionally, a pump unit has been used in which four pumps are used by controlling the number of operating pumps so that the discharge pressure is constant. These pump units are
The same 4 pumps are used as follows. In the case of four identical pumps, assuming that the flow rate of a single pump is Q ₁ = 1.0, 1 unit: Q ₁ × 1 = 1.0 2 units: Q ₁ × 2 = 2.0 3 units: Q ₁ × 3 = 3.0 4 units ... Q ₁ × 4 = 4.0 As a pump unit, 4 kinds of flow rates can be obtained.

[0003]

As described above, when four identical pumps are used, only four kinds of flow rates can be obtained as a pump unit, and there is a problem that there are few kinds of flow rates.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a unit-controlled water feed pump unit capable of obtaining various kinds of flow rates and performing a lean operation according to the water feed amount.

[0005]

In order to achieve the above-mentioned object, the present invention provides a pump unit which controls the number of operating pumps so that the discharge pressure is constant irrespective of the amount of water supply, and the cut-off head is substantially the same. Two pumps with the same flow rate but different flow rates
It is characterized by having a total of four units each.

[0006]

According to the present invention having the above-described structure, a total of four pumps, each having a shutoff head of the same and different flow rates, are provided. For example, a case where two pumps each having a flow ratio of 2.0 of two types are used will be described. According to the ISO standard, a single pump is manufactured with a common flow ratio of 2.0. If two pumps of this type are used, 1 pump ... Q ₁ = 1.0 1 pump ... Q ₂ = 2.0 2 pumps ... Q ₁ × 2 = 1.0 × 2 = 2.0 2 pumps… Q ₁ + Q ₂ = 1.0 + 2.0 = 3.0 2 units Q ₂ × 2 = 2.0 × 2 = 4.0 3 units (Q ₁ × 2) + Q ₂ = 4.0 3 units Q ₁ + (Q ₂ × 2) = 5.0 4 units [(Q ₁ × 2) + (Q ₂ × 2) = 6.0 In total, there are 6 types of flow patterns. As is apparent from the above, there are multiple overlapping flow rates.

Next, in the present invention, a case will be described in which two pumps each having a flow rate ratio of 1.6 are used. 1 unit ・ ・ ・ Q ₁ = 1.0 1 unit ・ ・ ・ Q ₂ = 1.6 2 units ・ ・ ・ Q ₁ × 2 = 1.0 × 2 = 2.0 2 units ・ ・ ・ Q ₁ + Q ₂ = 1.0 + 1.6 = 2 .6 2 units… Q ₂ × 2 = 1.6 × 2 = 3.2 3 units… (Q ₁ × 2) + Q ₂ = 3.6 3 units… Q ₁ + (Q ₂ × 2) = 4.2 4 units [(Q ₁ × 2) + (Q ₂ × 2) = 5.0 In this case, eight types of flow patterns can be provided as a pump unit, so that it is possible to operate without waste depending on the water supply amount. Become. In addition, the difference between the patterns is substantially uniform, and it is possible to realize a fine flow rate step.

As described above, when the flow rate ratio of the two types of pumps is 2.0 and 1.6, both types of flow rate patterns are increased as compared with the conventional example.

Further, according to the present invention, when the operation pattern of the pump is switched, a relay operation pattern is provided to prevent pressure drop. ─────────────────────── Operation pattern Operating pumps and number of pumps Flow rate ────── ────────────── ─ ── A 1.0 × 1 unit 1.0 ────── ───────────── ─── B 1.6 × 1 unit 1.6 ─────── ───────────── ─── C 1.0 × 2 units 2.0 ────── ───────────────── D 1 0.0 × 1 unit + 1.6 × 1 unit 2.6 ─────────────────────── E 1.6 × 2 unit 3.2 ──── ──────────────── ─── F 1.0 × 2 units + 1.6 × 1 unit 3.6 ────── ─────────── ─── ─── G 1.0 × 1 unit + 1.6 × 2 unit 4.2 ────── ───────────── ─── H 1.0 × 2 Unit + 1.6 x 2 units 5.2 ─── ——————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————— between the operation statuses above between between between between between between between between the eight and above can be changed as follows. In the above, the inside of the parentheses is the relay operation pattern.

Further, according to the present invention, the above four pumps are constructed in a panel type. At this time, the pump is an in-line type in which a suction port and a discharge port on the axis of the main shaft are provided so as to face each other, and two types of pumps having the same maximum diameter but different only in diameter and overall length are used. As a result, the entire apparatus becomes thin, and space can be saved.

Furthermore, according to the present invention, a fluid element is used as an excessive flow rate preventing device. In particular, the fluid element is provided on the suction header pipe side, and the nozzle for generating a rotating field in the fluid element is connected to the negative pressure generating device provided on the discharge side. Further, the negative pressure generating device is provided in one of the small pipes having a small flow rate. In this way, the device is compacted. Also, since the negative pressure generator is accompanied by loss,
It is better to attach it to a single pump with smaller output than to attach it to the discharge header pipe.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the number-of-units control type water supply pump unit according to the present invention will be explained with reference to FIG. In FIG. 1, reference numerals 1A, 1A; 1B, 1B are pumps, and these four pumps 1A, 1A; 1B, 1B are installed in parallel. The pump 1B has a larger flow rate than the pump 1A, and the flow rate ratio between the pump 1A and the pump 1B is set to a predetermined value. This flow ratio is 1.4 to 1.6, preferably 1.6. Then, these pumps 1 having different flow rates
Two pumps A and 1B are provided, four in total, and the number of operating pumps is controlled so that the required water supply amount is secured and the discharge pressure is constant.

The suction sides of the pumps 1A, 1A; 1B, 1B are connected to the suction header pipe 16 via sluice valves V _{1 to} V ₄ , and the fluid element 2 is provided on the inlet side of the suction header pipe 16.
Is installed.

[0014] The pump 1A, 1A; 1B, 1B discharge side of which is connected to the discharge header pipe 17 via the check valve V ₅ ~V ₈ and the partition valve V ₉ ~V _12. A negative pressure generator 8 is installed at the discharge end of the discharge header pipe 17. A pressure tank 18 is installed in the discharge header pipe 17. The negative pressure generating device 8 and the fluid element 2 are connected by a pipe 12 having a check valve 13.

FIG. 2 is a diagram showing another embodiment of the present invention. In this embodiment, the fluid element 2 is connected to a negative pressure generating device 8 provided on the discharge side of the pump 1A by a pipe 12. Other configurations are similar to those of the embodiment shown in FIG.

In the embodiment shown in FIGS. 1 and 2, 4
The pumps 1A, 1A; 1B, 1B of the table are panel-shaped. At this time, each of the pumps 1A, 1A; 1B, 1B is an in-line type in which the suction port and the discharge port on the axis of the main shaft are opposed to each other, and the two types of pumps 1A, 1B have the same maximum diameter, and the diameter and the total length. Only use different ones. As a result, the entire water supply pump unit becomes thin, so that space can be saved.

Next, the reason why it is optimal that two pumps having different flow rates are used, that is, four pumps in total, and the ratio of the two kinds of pumps is 1.6 will be described. First, various combinations will be exemplified in order to find the optimum combination.

(Combination 1) Q ₁ = 1.0 × 3 units, Q ₂ = 1.6 × 1 unit 1 unit ... Q ₁ = 1.0 1 unit ... Q ₂ = 1.6 2 units ... Q ₁ × 2 = 2.0 2 units ... Q ₁ + Q ₂ = 2.6 3 units ... Q ₁ × 3 = 3.0 3 units ... Q ₁ × 2 + Q ₂ × 1 = 3.6 4 units ... Q ₁ × 3 + Q ₂ × 1 = 4.6 As described above, only 7 flow rate patterns are possible. Also, Q ₂
Since there is only one pump, the usage frequency is biased. Here, since the more the flow pattern number is large and the maximum flow amount is small, more efficient pump operation can be performed, so each combination will be evaluated by an anonymous number obtained by dividing the pattern number by the maximum flow amount. Number of patterns / maximum flow rate = 7 / 4.6 = 1.52

(Combination 2) Q ₁ = 1.0 × 2 units, Q ₂ = 1.6 × 2 units As described in the section of the operation, the eight flow rate patterns can be realized without overlapping. Number of patterns / maximum flow rate = 8 / 5.2 = 1.54

(Combination 3) Q ₁ = 1.0 × 2 units, Q ₂ = 1.6 × 1
Unit, Q ₃ = 2.5 × 1 unit (2.5 = 1.6 ² ) 1 unit ・ ・ ・ Q ₁ = 1.0 1 unit ・ ・ ・ Q ₂ = 1.6 1 unit ・ ・ ・ Q ₃ = 2.5 2 units … Q ₁ × 2 = 2.0 2 units… Q ₁ + Q ₂ = 2.6 2 units… Q ₁ + Q ₃ = 3.5 2 units… Q ₂ + Q ₃ = 4.1 3 units… Q ₁ × 2 + Q ₂ × 1 = 3.6 3 units… Q ₁ × 2 + Q ₃ × 1 = 4.5 3 units… Q ₁ + Q ₂ + Q ₃ = 5.1 4 units… Q ₁ × 2 + Q ₂ + Q ₃ = 6.1 Real 9 flow rate You can pattern. Number of patterns / maximum flow rate = 9 / 6.1 = 1.48

(Combination 4) Q ₁ = 1.0 × 1 unit, Q ₂ = 1.6 × 3 unit 1 unit ... Q ₁ = 1.0 1 unit ... Q ₂ = 1.6 2 unit ... Q ₁ + Q ₂ = 2.6 2 units ... Q ₂ × 2 = 3.2 3 units ... Q ₁ × Q ₂ × 2 = 4.2 3 units ... Q ₂ × 3 = 4.8 4 units ... Q ₁ × 1 + Q ₂ × 3 = 5.8 7 Only flow pattern is possible. Also, since there is only one Q ₁ pump, the frequency of use will be biased. Number of patterns / maximum flow rate = 7 / 5.8 = 1.21

(Combination 5) Q ₁ = 1.0 × 1 unit, Q ₂ =
1.6 x 2 units, Q ₃ = 2.5 x 1 unit 1 unit ... Q ₁ = 1.0 1 unit ... Q ₂ = 1.6 1 unit ... Q ₃ = 2.5 2 units ... Q ₁ + Q ₂ = 2.6 2 units Q ₂ × 2 = 3.2 2 units Q ₁ + Q ₃ = 3.5 2 units Q ₂ + Q ₃ = 4.1 3 units Q ₁ × 1 + Q ₂ × 2 = 4. 2 3 units… Q ₁ × 1 + Q ₂ × 1 + Q ₃ × 1 = 5.1 3 units… Q ₂ × 2 + Q ₃ × 1 = 5.7 4 units… Q ₁ + Q ₂ × 2 + Q ₃ = 6.7 Real 9 flow patterns it can. As is apparent from the above, there are multiple overlapping flow rates. Number of patterns / maximum flow rate = 9 / 6.7 = 1.34

(Combination 6) Q ₁ = 1.0 × 1 unit, Q ₂ =
1.6 One ×, Q ₃ = 2.5 2 units one × ... Q ₁ = 1.0 ₁ single ... Q ₂ = 1.6 1 single ... Q ₃ = 2.5 2 cars ... Q ₁ + Q ₂ = 2.6 two _{... Q 1 + Q 3 = 3.5} 2 cars _{... Q 2 + Q 3 = 4.1} 2 cars ... Q ₃ × 2 = 5.0 ₃ cars _{... Q 1 × 1 + Q 2} × 1 + Q 3 × 1 = 5.1 3 units… Q ₁ × 1 + Q ₃ × 2 = 6.0 3 units… Q ₂ × 1 + Q ₃ × 2 = 6.6 4 units… Q ₁ + Q ₂ + Q ₃ × 2 = 7.6 Real 9 flow rate You can pattern. As is apparent from the above, there are multiple overlapping flow rates. Number of patterns / maximum flow rate = 9 / 7.6 = 1.18

(Combination 7) Q ₁ = 1.0 × 1 unit, Q ₂ =
1.6 × 1 unit, Q ₃ = 2.5 × 1 unit, Q ₄ = 4.0 × 1 unit (4.0 = 2.5 × 1.6) 1 unit ... Q ₁ = 1.0 1 unit ... Q ₂ = 1.6 1 single ... Q ₃ = 2.5 1 single ... Q ₄ = 4.0 2 cars _{... Q 1 + Q 2 = 2.6} 2 cars _{... Q 1 + Q 3 = 3.5} 2 cars ... Q ₁ + Q ₄ = 5.0 2 units Q ₂ + Q ₃ = 4.1 2 units Q ₂ + Q ₄ = 5.6 2 units Q ₃ + Q ₄ = 6.5 3 units Q ₁ + Q ₂ + Q ₃ = 5.1 3 units ... Q ₁ + Q ₂ + Q ₄ = 6.6 3 units ... Q ₁ + Q ₃ + Q ₄ = 7.5 3 units ... Q ₂ + Q ₃ + Q ₄ = 8.1 4 units ... Q ₁ + Q ₂ + Q ₃ + Q ₄ = 9.1 Substantially 10 flow patterns are possible. As is apparent from the above, there are multiple overlapping flow rates. Number of patterns / maximum flow rate = 10 / 9.1 = 1.10

As described above, Q ₁ = 1.0 × 2 units, Q ₂ =
It is best to use 1.6 × 2 units, and the number of patterns per maximum flow rate is large. Conversely speaking, the flow rate per pattern is small. That is, fine flow rate control can be performed.

Next, the structure of the excessive flow prevention device used in the embodiment shown in FIGS. 1 and 2 will be described with reference to FIG. In FIG. 3, FIG. 3 (a) is a partial sectional front view, and FIG. 3 (b) is a view on arrow III (b) of FIG. 3 (a). In FIG. 3, a fluid element 2 serving as an excessive flow rate preventing device is arranged on the suction side of the pumps 1A and 1B. Further, a negative pressure generator 8 is installed on the discharge side of the pumps 1A and 1B. The fluid element 2 includes a cylindrical body 3, a suction port 4, a discharge port 5, and a rotating field generating nozzle 6, and the discharge port 5 is connected to the suction port of the pump 1.

The negative pressure generator 8 comprises a main body 9, a diffuser 10 extending from the main body 9, and a nozzle 11 provided in the main body 9. The main body 9 is connected to the fluid element 2 by a bypass pipe 12. The nozzle 11 is connected to the rotation field generating nozzle 6 and the nozzle 11 is connected to the discharge ports of the pumps 1A and 1B. A check valve 13 is provided in the bypass pipe 12.

Next, the operation of the excessive flow prevention device constructed as described above will be described. (1) During normal operation During normal operation, the pressure in the negative pressure generator 8 is the fluid element 2
Higher than the pressure inside. Therefore, the handled liquid tries to flow from the negative pressure generating device 8 into the fluid element 2, but this flow does not occur because the check valve 13 is provided. As a result, the fluid element 2 does not suppress the flow on the suction side of the pumps 1A and 1B (see FIG. 3 (b)). (2) When the flow rate is excessive When the flow rate is excessive, the pressure inside the negative pressure generator 8 is the fluid element 2
It will be lower than the internal pressure (set to be lower). Therefore, as shown in FIG.
A flow is generated from the side through the bypass pipe 12 toward the negative pressure generating device 8. This flow becomes faster as the flow rate of the pumps 1A and 1B becomes larger. On the other hand, since the fluid field 2 is provided with the rotation field generating nozzle 6, the rotation field is generated by the above flow (see FIG. 4B). As a result, in order to suppress the flow on the suction side of the pumps 1A and 1B,
The flow rates of the pumps 1A and 1B are reduced. Then, when the pump flow rate decreases, the rotating field in the fluid element 2 weakens, so the effect of suppressing the flow on the suction side of the pumps 1A and 1B also weakens, and the pump flow rate increases. In this way, the pump is stably operated at either flow rate.

FIG. 5 is a diagram showing the effect of the above-mentioned excessive flow rate preventing device, in which the horizontal axis shows the flow rate (Q), and the vertical axis shows the lift (H) and the pump shaft power (L). As is clear from the figure,
When the flow rate discharged from the pumps 1A and 1B becomes excessive and the negative pressure generating device 8 operates to form a rotation field in the fluid element 2, that is, when the excessive flow rate preventing device operating point is reached, the flow rate becomes constant. It becomes a value.

[0030]

As described above, according to the present invention, since various kinds of flow patterns can be obtained, the lean operation can be performed according to the water supply amount, and the running cost can be reduced. Further, according to one aspect of the present invention, since the relay pattern is provided when the operation pattern is switched, there is no instantaneous pressure drop.

Further, according to the present invention, since the excessive flow prevention device is provided, even in the unlikely event, the main pipe on the suction side is not affected by pressure fluctuation or the like. Moreover, the pump itself is protected from output over. The excessive flow prevention device has a simple structure with no moving parts and is less likely to cause a problem.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a unit-controlled water feed pump unit according to the present invention.

FIG. 2 is a schematic diagram showing another embodiment of the unit-controlled water feed pump unit according to the present invention.

FIG. 3 is a diagram showing a configuration of an excessive flow prevention device in the unit-controlled water feed pump unit according to the present invention.
FIG. 3A is a partial cross-sectional front view, and FIG.
It is an I (b) arrow line view of (a).

FIG. 4 is a diagram showing a configuration of an excessive flow prevention device in the unit-controlled feed water pump unit according to the present invention.
FIG. 4A is a partial cross-sectional front view, and FIG.
It is a II (b) arrow line view of (a).

FIG. 5 is a diagram showing an effect of the excessive flow rate prevention device in the unit-controlled feed water pump unit according to the present invention.

[Explanation of symbols]

 1A, 1B Pump 2 Fluid element 3 Main body 4 Suction port 5 Discharge port 6 Rotation field generating nozzle 8 Negative pressure generating device 9 Main body 10 Diffuser 11 Nozzle 12 Bypass piping 13 Check valve

Claims (8)

[Claims] 1. A pump unit for controlling the number of operating pumps so that the discharge pressure is constant regardless of the amount of water supply, and a total of four pumps with two pumps each having a same cut-off head and different flow rates. A water supply pump unit characterized by that. 2. The ratio of the flow rates of the two types of pumps is 1.4 to
The feed pump unit according to claim 1, wherein the feed pump unit is 1.6. 3. When switching the operation pattern, a relay operation pattern is provided in between, and in the relay operation pattern, all pumps used before and after the switching are operated. The water supply pump unit according to claim 1 or 2. 4. A small pipe is provided for each of the four pumps, and the small pipe is provided with a pump, a sluice valve and a check valve provided in front of and behind the pump, and the suction side and the discharge side of the four small pipes. Is an in-line type with a suction header pipe and a discharge header pipe that combine small pipes into one, and the pump is an in-line type with the suction port and the discharge port facing each other on the axis of the main shaft, and the two types of pumps have the same maximum diameter. , Using only those that differ only in diameter and overall length
The feed pump unit according to claim 1, wherein the two small pipes are arranged in parallel on the same plane. 5. The feed pump unit according to claim 4, wherein the suction header pipe or the discharge header pipe is provided with a fluid element for preventing an excessive flow rate. 6. A fluid element for suppressing the flow by providing a rotating field in the element is provided in the suction header pipe portion, and a device for generating a negative pressure at the time of excessive flow is provided in the discharge header pipe portion, and the fluid element is rotated. The feed pump unit according to claim 4, wherein the field generating nozzle and the negative pressure generating device are connected by a bypass pipe, and a check valve is provided in the bypass pipe. 7. A fluid element for suppressing flow by providing a rotating field in the element is provided in a suction header pipe portion, and a device for generating a negative pressure at an excessive flow rate is provided on a pump discharge side of any of the small pipes. The feed water pump unit according to claim 4, wherein the rotary field generating nozzle of the fluid element and the negative pressure generating device are connected by a bypass pipe, and a check valve is provided in the bypass pipe. 8. The feed pump unit according to claim 7, wherein a device for generating a negative pressure when the flow rate is excessive is provided in one of two small pipes having a small flow rate.