JPS6146673B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a variable speed centrifugal pump device that supplies water at a constant pressure to housing complexes, etc. It is capable of supplying water as stably as in normal times even during a power outage, and has a simple structure. The aim is to provide an inexpensive device.

Traditionally, elevated water tanks or pressure tanks have been generally used as a water supply method for buildings such as apartment complexes, but in recent years, centrifugal pumps have been used from the viewpoint of overall economic efficiency in terms of equipment costs and operating power costs. Constant pressure water supply systems using speed control have gradually become popular. In this constant pressure water supply system, for example, a centrifugal pump is operated by an induction motor via a variable speed joint, or by a variable speed motor, so that even if the amount of water used in an apartment complex changes, the pump discharge output is always maintained. The variable speed joint or the variable speed electric motor is controlled to maintain a constant rotational speed of the centrifugal pump, thereby providing stable water supply. However,
In the former type of water supply system that uses an elevated water tank or pressure tank, if the storage capacity of the elevated water tank or pressure tank is selected appropriately, water can be supplied for a certain period of time even during a power outage, but the latter method With constant pressure water supply systems, the water supply would stop at the same time as a power outage, which was inconvenient, and water supply measures during power outages were extremely important. However, in order to supply water in the same way as during a power outage, it is necessary to install an emergency power supply with sufficient capacity to start and operate the electric motor that drives the water supply system in an emergency. However, the emergency power supply device is usually comprised of a prime mover such as an internal combustion engine, a generator, and a control device thereof, and is therefore very expensive.

In view of the above-mentioned conventional drawbacks, this invention improves and eliminates them by protruding the rotor shaft of the squirrel-cage induction motor from the main body toward the non-drive side, and using the shaft end for emergency use via an automatic clutch. A small emergency power supply device is installed that is connected to the power unit, operates in conjunction with the operation of the emergency power unit, and transmits power to the electromagnetic coupling.During normal times, the centrifugal pump is operated by a squirrel cage induction motor, and in the event of a power outage. This system uses an emergency power unit to operate a centrifugal pump to ensure a stable water supply at all times, both during normal times and during power outages. The structure of the present invention will be described below with reference to embodiments shown in the drawings.

The drawing shows a variable speed centrifugal pump device equipped with an emergency drive device.
The suction pipe 4 is connected to a water supply tank (not shown). 5 is an electromagnetic coupling that controls the rotational speed of the centrifugal pump 1; 6 is a squirrel cage induction motor that drives the electromagnetic coupling 5; together with the electromagnetic coupling 5, a variable speed motor is configured. 7 is an automatic clutch such as a centrifugal clutch, 8 is an emergency power unit such as an internal combustion engine, and these are installed on a common bed 9. The pump shaft 10 of the centrifugal pump 1 and the output shaft 1 of the electromagnetic coupling 5
1 by a shaft coupling 12, and a squirrel cage induction motor 6
The shaft end of the rotor shaft 13 protruding from the wooden body toward the non-drive side is connected to the driven portion 7a of the automatic clutch 7, and the other end is connected to the input shaft (not shown) of the electromagnetic coupling 5. The drive section 7b of the automatic clutch 7 is connected to the output shaft 14 of the emergency power unit 8, and is configured to be coupled to the driven section 7a when the rotational speed of the output shaft 14 exceeds a certain value. 15 is three-phase AC power supply 1
The squirrel cage induction motor 6 is started or stopped by an operation panel provided in the middle of the wiring between the squirrel cage induction motor 6 and the squirrel cage induction motor 6. 17 is a control panel that controls the excitation current of the electromagnetic coupling 5 and adjusts the rotation speed of its output shaft 11; 18 is a control panel that detects the pressure or flow rate in the water supply main pipe 3 and converts it into an electrical signal; The transmitter 19 is an automatic starting device that starts the emergency power unit 8, and is activated at the same time as a power outage.
20 is a small emergency power supply device connected by a belt 22 of the output shaft 14 of the emergency power device 8, and operates as the output shaft 14 rotates to generate electricity.
The generated current is sent to the control panel 17 via the control device 21.
to communicate.

Under normal conditions, when the squirrel cage induction motor 6 is started by operating the operation panel 15, the rotor shaft 13 rotates and the input shaft of the electromagnetic coupling 5 begins to rotate. At the same time, voltage is supplied to the control panel 17, and the output shaft 11 of the electromagnetic coupling 5 responds to the signal from the transmitter 18.
is rotated and transmitted to the pump shaft 10 of the centrifugal pump 1, and the rotational speed of the pump shaft 10 is controlled while supplying water at a constant pressure. During this constant pressure water supply, the driven part 7a of the automatic clutch 7 connected to the shaft end of the rotor shaft 13 of the squirrel cage induction motor 6 rotates, but the emergency power device 8 is not operating and the automatic clutch 7 is driven. The section 7b is stationary, the automatic clutch 7 is not engaged, and the squirrel cage induction motor 6, the electromagnetic coupling 5 and the centrifugal pump 1 are operated independently of the emergency power unit 8. When a power outage occurs, the current to the squirrel cage induction motor 6 is cut off, the rotation of the rotor shaft 13 is stopped, and the motor is in a free state. At this time, the automatic startup device 19
is activated, the emergency power unit 8 starts, and the output shaft 1
4 begins to rotate. At the same time, the small emergency power supply device 20 starts operating and transmits the generated electricity to the control panel 17 via the control device 21. When the rotational speed of the output shaft 14 of the emergency power device 3 increases and exceeds a certain value, the driving section 7b and the driven section 7a of the automatic clutch 7 are coupled, the rotor shaft 13 is rotated, and then the electromagnetic coupling The input shaft of No. 5 is rotated. The output shaft 11 rotates while being controlled by the control panel 17 that receives the signal from the transmitter 18.
The pump shaft 10 of the centrifugal pump 1 is rotated to supply water at a constant pressure.

During water supply during the above power outage, squirrel cage induction electric machine 6
The rotor shaft 13 can be freely rotated from the outside, and the electromagnetic joint 5 is also operated by the small emergency power supply device 20, so water can be supplied without any problems. In addition, since the control power of the electromagnetic coupling 5 is extremely small, about 5% or less compared to the input of the squirrel cage induction motor 6, the capacity of the small emergency power supply device 20 may be small, and it can be replaced with a generator. A storage battery may also be used.

According to the above configuration, water can be supplied using a small emergency power supply device with a smaller capacity than a generator conventionally used to drive the squirrel cage induction motor 6 and the electromagnetic coupling 5. That is, if the driving power of the centrifugal pump 1 at the maximum rotational speed is P, and the output and efficiency of the squirrel cage induction motor 6 with the electromagnetic coupling 5 at the maximum rotational speed are W and η _M , then W = (1.05 ~ 1.2) P... (1) If the required input at the maximum rotational speed of the squirrel cage induction motor 6 with electromagnetic coupling 5 is W', then W' = W/η _M = (1.05 to 1.2) P/η _M ... ...(2) If the required output of the emergency power unit 8 is P', and the required output and efficiency of the small emergency power unit 20 are w and η _g , then P' = (1.15 to 1.2) P + W / η _g ... (3) W=(0.02~0.1)W′...(4) Substituting equations (1) and (2) into equation (3), we get P′=(1.15～1.2)p+(0.02～0.1)×( 1.05~1.2) P/ηMηg・≒1.2P……(5) The required output, efficiency, and required input of the generator of the conventional emergency power supply device are respectively W _G , η _G , W′ _G , and the generator is operated. The required output of the emergency power plant is
P″, then P″ = (1.15~1.2) W′ _G = (1.15~1.2) W _G /η _G …(6) W _G = (1.3~1.5) W′ …(7) (6) Substituting equations (2) and (7) into the equation, P″=(1.57~2.16)P/η _M η _G η _M η If _G is assumed to be around 0.95, then P″=(1・75~24 )P ...(8) Comparing equations (8) and (5), it is clear that the required output of the emergency power system according to the present invention is the same as the generator drive of the emergency power system when the present invention is not used. It is much smaller than electric power, and does not require a large-capacity generator.

As explained above, this invention detects the discharge pressure of a centrifugal pump, converts it into an electrical signal, and controls a variable speed motor using this electrical signal to maintain the discharge pressure of the centrifugal pump at a constant pressure. In the pump device, the variable speed electric motor is composed of a squirrel cage induction motor and an electromagnetic coupling installed on one side of the rotor shaft of the motor to control the rotational speed according to the electric signal, and The rotor shaft of the type induction motor projects to both sides of the motor body, one end of which is connected to the centrifugal pump via the output shaft of the electromagnetic coupling, and the other end is equipped with an automatic starting device that operates simultaneously with a power outage. An emergency power device is arranged, and a centrifugal clutch is installed between the emergency power device and the squirrel cage induction motor so that rotational force can be transmitted only from the emergency power device side. Since a small emergency power supply device for emergency control of the electromagnetic joint is interlocked with the output shaft, constant pressure water can be supplied even during a power outage as in normal times. In particular, the rotor shaft of a squirrel-cage induction motor becomes free during a power outage, and the driving force of the emergency power unit is transmitted to the centrifugal pump through the rotor shaft of the squirrel-cage induction motor via a centrifugal clutch without any hindrance. Furthermore, during a power outage, the electromagnetic joint attached to the squirrel cage induction motor can be used as is to control constant pressure water supply by supplying power from a small emergency power supply. Furthermore, in the event of a power outage, only the power required to control the electromagnetic coupling needs to be generated by a small emergency power supply, making it simple and inexpensive.

[Brief explanation of the drawing]

The drawing is a schematic side view showing the configuration of a variable speed centrifugal pump device equipped with an emergency drive device. 1... Centrifugal pump, 5... Electromagnetic coupling, 6... Squirrel cage induction motor, 7... Automatic clutch, 8... Emergency power device, 20... Small emergency power supply device.

Claims (1)

[Claims] 1. In a variable speed centrifugal pump device for constant pressure water supply, which detects the discharge pressure of a centrifugal pump and converts it into an electrical signal, and controls a variable speed motor using this electrical signal to maintain the discharge pressure of the centrifugal pump at a constant pressure, the variable speed The electric motor is composed of a squirrel-cage induction motor and an electromagnetic coupling installed on one side of the rotor shaft of the electric motor to control the rotational speed according to the electric signal, and
The rotor shaft of the squirrel-cage induction motor projects to both sides of the induction motor body, one end of which is connected to the centrifugal pump via the output shaft of the electromagnetic joint, and the other end is equipped with an automatic starting device that operates simultaneously with a power outage. A centrifugal clutch is installed between the emergency power device and the squirrel cage induction motor so that rotational force can be transmitted only from the emergency power device side,
A variable speed centrifugal pump device with an emergency drive device, characterized in that a small emergency power source device for emergency control of the electromagnetic coupling is interlockably provided on the output shaft of the emergency power device.