JP2004257340A - Power recovery pump device and flow rate controller using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recover power while controlling heat medium such as cold water or hot water under the condition of constant water supplying pressure while controlling variable flow rate without performing pump rotation speed control by an inverter, and to save electrical power at high efficiency. <P>SOLUTION: A water feeding pump 7 for feeding the heat medium is mechanically connected to a prime mover 15 for driving the water feeding pump 7 by a coupling 17. A rotating shaft 15b of the prime mover 15 is mechanically connected to a shaft 16a of a power recovery hydraulic turbine 16 by a contactable and separable centrifugal clutch 18. A return bypass passage 19 branched from a discharge side of the water feeding pump 7 is connected to a suction side of the water feeding pump 7 through the power recovery hydraulic turbine 16, and a control valve 20 is provided in the middle of the return bypass passage 19. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a power recovery pump device that recovers the power of a pump only at a feed pipe portion without using a return pipe, and feeds a fluid with variable flow rate control under a constant water feed pressure condition. To a flow control device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a building such as a building, for example, an air conditioning system and a district cooling / heating system shown in FIG. 4 have been adopted. In this air conditioning system, cold or hot water from a return header 50 is sent by primary water pumps 51, 51, passes through a cold / hot water heat source such as a refrigerator 52, a heat exchanger 53 using a boiler, etc., and is heated to a predetermined temperature. , To the first feed header 54, and then sent to the second feed header 57 by the secondary water pumps 55, 55. Then, after being supplied to the heat exchangers (air conditioners) 58, 58... Arranged in each part (room) via the second feed header 57, the heat is circulated to the return header 50.
[0003]
In the air conditioning system, the secondary water pumps 55, 55... Disposed between the first feed header 54 and the second feed header 57 include an inverter 56, and are provided between the second feed header 57 and the return header 50. Is provided with a differential pressure sensor 61, and a flow rate sensor 60 is provided on an inlet-side return pipe of the return header 50.
[0004]
For example, in the heat exchangers (air conditioners) 58, 58,... Installed in each room, the control two-way valves 59, 59,. When the flow rate changes, the flow rate sensor 60 detects the flow rate, and is controlled by the number control controller 62 so as to be the minimum number of operation units, and the differential pressure between the second feed header 57 and the return header 50 is detected by the differential pressure sensor 61. By controlling the rotation speed of the inverters 56, 56,... Of the secondary water pumps 55, 55. It is supposed to do.
[0005]
On the other hand, recently, a power recovery apparatus for minimizing the energy consumption of a pump prime mover has been proposed. As shown in FIG. 5, this power recovery device utilizes the fact that a cold / hot water pump 60 is installed on a lower floor and an air conditioner 63 is installed on an upper floor in an open type pipeline, A water wheel 62 using a pump is attached to the piping side, and the axial force of the water wheel 62 is connected to a motor (electric motor) 61 of the pump to collect the energy of the cold and hot water falling from the upper floor to the lower floor. This saves energy consumed by the prime mover 61. As described in Patent Document 1 below, this power recovery device also drives a water turbine with a high-pressure concentrated liquid from a reverse osmosis membrane module in a desalination device using a load portion corresponding to an air conditioner as a reverse osmosis membrane. It is also applied to recovering energy.
[0006]
[Patent Document 1]
JP-A-57-4286
[Problems to be solved by the invention]
The pump equipment in the air-conditioning system is intended to reduce the amount of electric power consumption by reducing the number of pumps when the required heat exchange amount is reduced. In addition, since the inverter is controlled to increase the pump rotation speed, the power consumption of the pump increases (in proportion to the cube of the rotation speed). Therefore, there is a problem that the energy saving effect cannot be expected even though the load on the heat exchanger (air conditioner) 58 is reduced. In addition, when an inverter is used, a problem of harmonics occurs, and there is a problem that measures need to be taken.
[0008]
On the other hand, in the case of the power recovery pump device described above, the return pipe from the air conditioner must be piped to the position of the pump prime mover, which is subject to restrictions on piping construction, and when a large number of pumps are installed, In addition, since the falling energy of cold and hot water is dispersed, there has been a problem that the recovery efficiency is significantly reduced.
[0009]
Therefore, a first object of the present invention is to recover the power of a pump only at a feed pipe portion without using a return pipe in a power recovery pump device that drives a water turbine to recover energy.
[0010]
The second problem is that the flow control device recovers power while controlling the flow rate of a fluid such as cold water or hot water under a constant water supply pressure condition without controlling the rotation speed of the pump by an inverter, thereby achieving high efficiency. The purpose is to save energy of electricity.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, as a first aspect of the present invention, a water pump and a motor for driving the water pump are mechanically connected, and a rotating shaft of the motor and a shaft of a power recovery turbine are mechanically connected. A power recovery pump device is provided, wherein a return bypass path branched from the discharge side of the water supply pump is connected to the suction side of the water supply pump through the power recovery turbine. .
[0012]
According to the first aspect of the present invention, the return bypass is provided on the discharge side and the suction side of the water supply pump, and the power recovery turbine is disposed in the middle of the return bypass. Power can be recovered. In addition, the return pipe is not subject to any restrictions on the pipe construction, and even when a pump is installed for each feed pipe, by adopting the above-described configuration for each feed pipe, power recovery efficiency is improved. It does not drop.
[0013]
Next, in order to solve the second problem, as a second aspect of the present invention, a flow rate control device for feeding a fluid while performing variable flow rate control under a constant water pressure condition,
A water supply pump for supplying the fluid, and a motor that drives the water supply pump are mechanically connected, and a rotating shaft of the motor and a shaft of a power recovery turbine are mechanically connected, and Flow rate control characterized in that a return bypass passage branched from the discharge side of the pump is connected to the suction side of the water supply pump by relaying the power recovery turbine, and a control valve is provided in the middle of the return bypass passage. An apparatus is provided.
[0014]
According to the second aspect of the present invention, in addition to the advantages of the first aspect, it is possible to arbitrarily adjust the supply amount and the water supply pressure by opening and closing a control valve disposed in the middle of the return bypass. Therefore, it is possible to recover the power while controlling the variable flow rate under a constant water supply pressure condition, and it is possible to save the power with high efficiency.
[0015]
According to a third aspect of the present invention, there is provided a power recovery pump device according to the first aspect or a flow rate control device according to the second aspect, wherein the water pump and the prime mover are mechanically connected by a coupling.
[0016]
According to a fourth aspect of the present invention, there is provided the power recovery pump device or the power recovery pump device according to any one of the first to third aspects, wherein a rotating shaft of the prime mover and a shaft of the power recovery turbine are connected to and separated from each other by a centrifugal clutch. Item 3. A flow control device according to any one of Items 2 to 3.
[0017]
According to a fifth aspect of the present invention, in the flow rate control device, the flow rate control device according to any one of claims 2 to 4, wherein a plurality of flow paths are formed between the headers, and the flow control apparatus is disposed in each of the flow paths. An apparatus is provided.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an overall view of an air conditioning system according to the present invention, and FIG. 2 is an enlarged view of a main part of a water supply pump unit.
[0019]
In the air conditioning system 1 shown in FIG. 1, cold water or hot water from the return header 2 is sent by primary water pumps 3 and 3 and passes through a cold / hot water generator such as a refrigerator 4 and a heat exchanger 5 using a boiler. After reaching a predetermined temperature, the temperature reaches the first feed header 6 and is then sent to the second feed header 8 by the secondary water pumps 7, 7,. Then, after being sent to the heat exchangers (air conditioners) 9, 9... Arranged at the respective parts via the second feed header 8, they are circulated to the return header 2.
[0020]
The secondary water pump 7 disposed between the first feed header 6 and the second feed header 8 is provided with a flow control device 10 having a power recovery function. As shown in detail in FIG. 2, the flow control device 10 mechanically connects a blade shaft of the water supply pump 7 and a driving shaft 15a of a motor 15 for driving the water supply pump 7 by a coupling 17 or the like. At the same time, the rotating shaft 15b protruding to the rear side of the prime mover 15 and the shaft 16a of the power recovery turbine 16 are mechanically connected by a centrifugal clutch 18 or the like which is preferably freely detachable. A return bypass passage 19 branched from the discharge side of the power supply water turbine 16 is connected to the suction side of the water supply pump 7 by relaying the power recovery turbine 16, and a control valve 20 is provided in the return bypass passage 19. ing. Here, as the power recovery turbine 16, for example, a general spiral pump can be used, and the spiral pump is connected in reverse to the usual case, that is, water flows into the discharge side and is discharged from the suction side. What is necessary is just to arrange so that an impeller may be reversed. Although the position of the control valve 20 is provided on the discharge-side bypass of the power recovery turbine 16 in the example shown in the figure, it may be provided on the suction-side bypass of the power recovery turbine 16.
[0021]
On the other hand, a pressure sensor 11 is provided in the second feed header 8, and a flow sensor 12 is provided in a return pipe before the return header 2, and these measurement signals are input to the valve controller 13. ing.
[0022]
In the operation of the air conditioning system, for example, at the time of maximum load operation, the control valve 20 is fully closed, and a heat medium such as cold water or hot water is sent to the second feed header 8 side. In the heat exchanger (air conditioner) 9, when the control-side two-way valves 14, 14... Are controlled in accordance with the required heat exchange amount to change (reduce) the secondary-side heat medium circulation amount, the flow rate sensor 12 Detects the flow rate, and the valve control controller 13 controls the opening of the control valve 20 according to the reduced water supply amount. When the control valve 20 is opened and the cooling water or hot water heat medium flows through the return bypass passage 19, the power recovery turbine 16 is rotated, and the power of the prime mover 15 is reduced.
[0023]
The control of opening and closing of the control valve 20 controls the opening and closing of the control valve 20 based on the measurement value of the pressure sensor 11, and controls the water supply pressure by changing the return bypass flow rate. If the rotational speed control is performed using an inverter, as shown in FIG. 3, the operating point changes from point A to point B (flow rate: Q2, head H1). The pump operates at the point A (flow rate: Q1, head H1), sends the flow rate Q2 to the secondary side, and returns the remaining (Q1-Q2) flow rate to the recovery pump by return bypass. Power is collected by flowing. In addition, even in the case of parallel operation in which a plurality of water pumps 7 are arranged as in the illustrated example, variable flow control up to the maximum flow rate can be performed while the discharge pressure is kept constant.
[0024]
(Another embodiment example)
(1) In the above embodiment, the present invention has been described by taking an air conditioning system as an example. However, the present power recovery pump device can be applied to a general pump that performs variable flow control.
[0025]
(2) Although the control of the number of operating pumps is not performed in the above embodiment, the flow rate control by the power recovery pump according to the present invention may be performed together with the control of the number of operating pumps.
[0026]
【The invention's effect】
As described in detail above, according to the present invention as set forth in claims 1, 3, and 4, in a power recovery pump device that drives a water turbine to recover energy, a pump is provided only at a feed pipe portion without using a return pipe. Power can be recovered.
[0027]
Further, according to the present invention as set forth in claims 2 to 5, in the flow control device, the flow rate of the fluid such as cold water or hot water is controlled under a constant water supply pressure condition without controlling the rotation speed of the pump by the inverter. While recovering power, energy can be saved with high efficiency.
[Brief description of the drawings]
FIG. 1 is an air conditioning system diagram according to the present invention.
FIG. 2 is an enlarged view of a main part of a water pump unit.
FIG. 3 is a characteristic curve diagram of a pump (horizontal axis: flow rate, vertical axis: total head).
FIG. 4 is a diagram of a conventional air conditioning system.
FIG. 5 is a configuration diagram of a conventional power recovery pump device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Air conditioning system, 2 ... Return header, 3 ... Primary water pump, 4 ... Refrigerator, 5 ... Heat exchanger, 6 ... 1st feed header, 7 ... Secondary water pump, 8 ... 2nd feed header, 9 ... Heat exchanger (air conditioner), 10: Flow control device, 11: Differential pressure sensor, 12: Flow sensor, 13: Valve control controller, 15: Motor, 16: Power recovery turbine, 17: Coupling, 18: Centrifugal clutch , 19: return bypass passage, 20: control valve

Claims (5)

A water pump and a motor that drives the water pump were mechanically connected, and a rotating shaft of the motor and a shaft of a power recovery turbine were mechanically connected and branched from the discharge side of the water pump. A power recovery pump device, wherein a return bypass passage is connected to the suction side of the water supply pump by relaying the power recovery turbine. A flow control device for supplying a fluid while performing variable flow control under a constant water supply pressure condition,
A water supply pump for supplying the fluid, and a motor that drives the water supply pump are mechanically connected, and a rotating shaft of the motor and a shaft of a power recovery turbine are mechanically connected, and Flow rate control characterized in that a return bypass passage branched from the discharge side of the pump is connected to the suction side of the water supply pump by relaying the power recovery turbine, and a control valve is provided in the middle of the return bypass passage. apparatus. The power recovery pump device according to claim 1 or the flow control device according to claim 2, wherein the water pump and the motor are mechanically connected by a coupling. The power recovery pump device according to claim 1, wherein the rotation shaft of the prime mover and the shaft of the power recovery turbine are connected to and separated from each other by a centrifugal clutch. Flow control device. The flow control device according to any one of claims 2 to 4, wherein the flow control device has a plurality of flow paths formed between the headers and is disposed in each of the flow paths.

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