JP2016142184A - Fire pump unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent problems such as fastening of impellers and the like, clogging of a hole, and defects of a pressure detecting portion, and to detect failure in advance.SOLUTION: A fire pump unit includes a pump 30 pressure-feeding water for fire-fighting, an inverter 60 for speed-variably operating a motor 40 having a prescribed frequency F to drive the pump 30, and a pump control device 50 for implementing a standby operation of the motor 40 by the inverter 60 with a first low-speed frequency F1 lower than a rated frequency F. The pump control device 50 detects failure of the pump 30 or the inverter 60, outputs a failure signal, and operates the motor 40 with the rated frequency F by the invertor 60 in inputting a start signal or inputting a periodical inspection signal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fire pump unit installed in a building.

  The building is equipped with a fire pump unit for discharging water in the event of a fire. There are two types of water discharge: a fire hydrant that discharges water through a hose by human power, and a sprinkler facility that automatically discharges water when a fire occurs.

  Such a fire extinguishing pump unit is required to operate reliably in the event of a fire, but since it is normally stopped, water stays in the pump for a long time. For this reason, the hardness component in the water is deposited on the seal part and the impeller is fixed, the protection device operates when the pump is started, the voltage drop occurs due to the large starting current that flows when the pump is started, and the electromagnetic switch does not operate normally, etc. There was a fear.

  In order to prevent such unstartable accidents, it is conceivable to detect in advance the internal fixation of the impeller and other pumps by conducting periodic inspections, but there is a limit to the frequency of inspections, and it is not possible to prevent them completely. Can not.

  In case of fire, the normal power supply may cause a power failure, and an emergency power supply may be used. Since other disaster prevention devices operate simultaneously when a fire breaks out, there may be a case where the power supply capacity is insufficient and the power supply situation is not as good as during the test run.

  In order to prevent such a voltage drop due to a large starting current, various fire extinguishing pump units that control the pressure on the pump discharge side to a predetermined value by gradually increasing the rotation speed of the electric motor using an inverter are proposed. (For example, refer to Patent Documents 1 to 6.)

JP 2010-014126 A Japanese Patent No. 4317088 Japanese Patent No. 4317093 Japanese Patent No. 4778994 Japanese Patent No. 5138505 Japanese Patent No. 5132653

  The fire pump unit using the above-described inverter has the following problems. That is, as an apparatus for driving the pump of the fire-extinguishing pump unit, the inverter has an advantage that the start-up current is reduced by the soft start function so that the power supply voltage does not drop compared to the conventional electromagnetic switch. However, there is a risk of failure stop due to “acceleration overcurrent” at the time of starting.

In addition, in the case of a fire pump unit equipped with a pressure tank corresponding to the sprinkler equipment, calcium hydroxide eluted from the concrete fire water tank deposits inside the pressure switch for starting the pump, and the water pressure detection hole is clogged. There was a risk that a pressure drop could not be detected and the electric pump could not be started.
Accordingly, the present invention provides a fire-extinguishing pump unit that can prevent the fixing of an impeller, clogging of a hole, malfunction of a pressure detection unit, and the like, and can detect a failure in advance, even when it does not operate for a long period of time. It is aimed.

  In order to solve the above problems and achieve the object, the fire pump unit of the present invention is configured as follows.

  An electric pump for pressure-feeding water for fire extinguishing, an inverter for variable speed operation of an electric motor having a predetermined rated frequency for driving the electric pump, and control for causing the electric motor to perform a standby operation at a low speed lower than the rated frequency by the inverter Department.

  An electric pump that supplies water for extinguishing water under pressure, an inverter that operates the electric motor that drives the electric pump at a variable speed, and a trial operation of the electric motor at a low frequency every predetermined time from a stop state. During the trial operation, the electric pump Alternatively, when a failure of the inverter is detected, a failure signal is output, and when there is no failure abnormality, the test operation is stopped, and the motor is operated at the rated frequency when the start signal is input in either the test operation or the stop state. And a control unit for driving.

  According to the present invention, even if it does not operate for a long period of time, it is possible to prevent the fixing of an impeller, clogging of a hole, malfunction of a pressure detection unit, and the like, and to detect a failure in advance.

Explanatory drawing which shows the structure of the fire-extinguishing pump unit which concerns on the 1st Embodiment of this invention. The front view which shows the pump apparatus integrated in the fire extinguishing pump unit. The side view which shows the pump apparatus. Sectional drawing which shows typically the flow of the water inside the pump apparatus. Explanatory drawing which shows the relationship between the discharge flow rate by the fire extinguishing pump unit, and a head. Explanatory drawing which shows the structure of the fire-extinguishing pump unit which concerns on the 2nd Embodiment of this invention. The front view which shows the pump apparatus integrated in the fire extinguishing pump unit. The side view which shows the pump apparatus.

  FIG. 1 is an explanatory diagram showing a configuration of a fire pump unit 10 according to a first embodiment of the present invention, FIG. 2 is a front view showing a pump device incorporated in the fire pump unit, and FIG. It is a side view.

  The fire fighting pump unit 10 according to the first embodiment of the present invention includes a pump device 20, a pump control device 50 for controlling the pump device 20, and a water discharge device 90 connected to the pump device 20. ing.

  The pump device 20 includes a pump 30 and an electric motor 40 that drives the pump 30. A suction pipe that is submerged in a fire extinguishing water tank that is a water source is connected to the suction side of the pump 30.

  The pump 30 includes a casing 300. A suction port 301 and a discharge port 302 are formed in the casing 300. A rotating shaft 310 that is rotationally driven by the electric motor 40 is provided in the casing 300, and a first-stage impeller 320, a second-stage impeller 320, and a third-stage impeller 340 are provided in series on the rotating shaft 310. Note that reference numeral 321 in FIG. 4 denotes a mouse portion of the first stage impeller 320.

  In addition, on the discharge side of the pump 30, there is provided a priming tank 31 that gives priming water to the internal cavity. A constant level of water is always maintained in the expiratory water tank 31.

  Furthermore, a pressure detector 32 that detects the discharge pressure is connected to the discharge side of the pump 30 and is connected to a water discharge device 90 via a check valve 33 and a supply pipe 34.

  The electric motor 40 is connected to a pump control device (control unit) 50 and drives the pump 30 at a rotation speed corresponding to a frequency input from an inverter 60 described later.

  The pump 30 is designed and manufactured on the premise of a predetermined rated frequency F (for example, 60 Hz). This is because when two types of pumps corresponding to commercial power frequencies of 50 and 60 Hz are manufactured, the fire extinguishing pump unit itself will also be of two types. There is an advantage that can be reduced.

  The pump control device 50 includes an inverter 60, and a control circuit 70 that controls the inverter 60, the pump device 20, and the like and performs various calculations based on output signals from detectors provided in each unit. .

  The inverter 60 includes a rated frequency F of the electric motor 40, a first low-speed frequency F1 lower than the rated frequency F (for example, 20 to 30 Hz), a second higher than the first low-speed frequency F1 and lower than the rated frequency F. A low speed frequency F2 (for example, 48 to 54 Hz) is generated. The first low-speed frequency F1 is preferably as low as possible from the viewpoint of energy saving. However, since there is a frequency at which a trip occurs, the frequency at which a trip does not occur and the second low-speed frequency F2 is 80 to 90% of the rated frequency F. It is preferable to determine so that

  The control circuit 70 performs a water discharge operation, a standby operation, a periodic inspection operation, etc. in the event of a fire in accordance with a program incorporated in an internal microcomputer or the like, and performs malfunction prevention, malfunction detection, and the like.

  The control circuit 70 includes a commercial frequency supply circuit 80 that bypasses the inverter 60, and an electromagnetic switch 81 that directly connects the electric motor 40 and the power source in response to a failure of the inverter 60 or the like.

  The water discharge device 90 includes, for example, a water sprinkling unit 91 and a fire detection unit 92 that are provided on the ceiling of a building and the like and sprinkle water that has been pressurized by the pump 30.

  The fire pump unit 10 configured in this manner operates as follows. The fire-extinguishing pump unit 10 is operated by the pump control device 50 in a water discharge operation, a standby operation, and an intermittent test operation. Each operation mode will be described. Note that the standby operation and the intermittent test operation can be selected by a user setting.

The water discharge operation is an operation used for normal fire extinguishing. When a fire occurs in the building, the fire detection unit 92 detects the fire and the water sprinkling unit 91 sprays water. Due to this watering, the internal pressure of the supply pipe 34 suddenly decreases, and when the decrease signal is detected, the pump control device 50 starts the electric motor 40 and rotates the pump 30 at the rated frequency F. F in FIG. 5 shows the relationship between the discharge flow rate and the head in the water discharge operation.
Since the operation is performed at the rated frequency F, acceleration / deceleration operation that causes overcurrent / overvoltage is not performed. When the detection of the fire is finished, the electric motor 40 is stopped.

  The standby operation is an operation for preventing the impeller from sticking or the like. That is, the inverter 60 drives the electric motor 40 at the first low-speed frequency F1 at a normal time when no fire has occurred. Accordingly, the pump 30 rotates at a low speed. At this time, water is not discharged to the supply pipe 34 and the pump casing of the pump 30 is not heated by the operation at a flow rate returning to the priming tank 31 through the relief orifice. FIG. 4 shows the flow of water in the pump 30.

Here, the relief orifice is for preventing the temperature rise in the pump and preventing damage even when the pump is in a shut-off operation. Incidentally, the hydrostatic head 30 m> 14 m (at the time of the first low-speed operation of 30 Hz) Therefore, the operation is cut off when viewed as a whole pump. However, since there is a backflow leakage from the mouth portion 321 of the first stage impeller 320 to the suction port 301, there is water circulation inside the pump. That is, the suction port 301 to the first stage impeller 320 to the second stage impeller 330 to the third stage impeller 340 to the discharge port 302 to the mouth part 321 to the suction port 301 of the first stage impeller 320.

  In addition, when a fire is detected, it shifts to a water discharge operation. In this case, since the control of the inverter 60 is not the variable speed control in which the discharge pressure becomes a predetermined value, the acceleration / deceleration operation that causes the occurrence of overcurrent / overvoltage is not performed.

  FIG. 5 is an explanatory diagram showing the relationship between the discharge flow rate by the fire pump unit 10 and the head. F1 in FIG. 5 indicates the relationship between the discharge flow rate and the head in the standby operation.

  In addition, when a failure of the pump device 20 and the inverter 60 is detected during the standby operation, a failure signal is output as an abnormality. Thereby, after turning off the power, the user can perform an inspection or the like to prevent troubles during the water discharge operation.

  Note that the standby operation at the first low-speed frequency F1 of the inverter 60 is used only as a failure detection function, and when the first failure occurs, a failure signal is output, and further, the retry function waits again after a certain period of time has elapsed. When the operation is started and a predetermined number of failures are detected, the retry function may be stopped.

  The intermittent test operation does not operate continuously like the standby operation, but operates intermittently from the viewpoint of energy saving. That is, after the power is turned on, the pump 30 is trial-run by driving the motor 40 at the first low-speed frequency F1 at regular time intervals (for example, every 24 hours). During the test run for a certain period of time, if a failure is detected, a failure signal is output, and if there is no abnormality, the operation is stopped. In addition, in any state at the time of test operation or stop, when a start signal such as detecting a fire is input, the operation proceeds to the above-described water discharge operation.

In addition, with an emphasis on reliability, while producing two types of fire extinguishing pump units equipped with one of two types of electric pumps with a rated frequency of commercial frequency 50, 60 Hz,
In any of the above-described operation modes, when a failure relating to the inverter 60 occurs (one or more times), the electric pump is stopped and then switched to a commercial operation circuit using an electromagnetic switch.

  As a result, even if a failure occurs in the inverter, it is possible to switch to the commercial frequency supply circuit 80 by the electromagnetic switch 81 and drive the motor 40 at the rated frequency 50 or 60 Hz. Reliability can be improved.

  As described above, according to the fire pump unit 10 according to the present embodiment, when a fire occurs, constant speed operation is performed at the rated frequency, and acceleration / deceleration operation that causes overcurrent / overvoltage is not performed at all. So that the reliability of the unit is improved. When a fire breaks out, there is no voltage drop due to start-up current as in commercial operation, no overcurrent during acceleration specific to the inverter occurs, and impellers, mechanical seals, etc. are always rotating, so precipitation of underwater components There is no risk of sticking accidents.

  FIG. 6 is an explanatory view showing the configuration of a fire fighting pump unit 10A according to the second embodiment of the present invention, FIG. 7 is a front view showing a pump device 20A incorporated in the fire fighting pump unit 10A, and FIG. It is a side view showing pump device 20A built in pump unit 10A. 5 to 7, the same functional parts as those in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The fire extinguishing pump unit 10A is provided with a pump device 20A. In the pump device 20 </ b> A, a pressure tank 100 for a sprinkler is connected to a supply pipe 34 via an electric on-off valve 101. In addition, a jockey pump 110 is provided for preventing malfunction by compensating for the pressure drop of the starting pressure tank 100.

  As with the above-described fire pump unit 10, the fire pump unit 10A is operated by the water discharge operation, the standby operation, and the intermittent test operation by the pump control device 50, and further has an additional operation mode. Therefore, additional operation modes D1 to D3 will be described. Note that the standby operation and the intermittent test operation can be selected by a user setting.

  The operation mode D1 detects the discharge pressure Pt at regular intervals when the motor 40 is operated at the first low-speed frequency F1 in the standby operation or the intermittent test operation. When the discharge pressure Pt becomes equal to or lower than the set pressure P1 higher than the unit start pressure Pk, operation is performed at the second low speed frequency F2, and when the discharge pressure Pt becomes the unit stop pressure Pz, standby operation or intermittent operation is performed. Return to commissioning.

  Since the second low-speed frequency F2 is an operation frequency capable of supplying a small amount of water into the pressure tank 100 when the pump 30 generates the unit starting pressure P1, the jockey pump 110 is not used in this mode. Moreover, the pressure drop of the starting pressure tank 100 can be compensated. That is, installation of the jockey pump 110 becomes unnecessary.

  F2 in FIG. 5 indicates the relationship between the discharge flow rate and the head during water supply to the pressure tank. Since the necessary flow rate is 20 L / min, the head shown by X2 in FIG. 5 is generated.

  In the operation mode D2, in the standby operation or the intermittent test operation, the electric on-off valve is opened at regular intervals, and the discharge pressure Pt is detected at regular intervals. When the discharge pressure Pt does not decrease to the set pressure P1 set higher than the unit starting pressure Pk after a certain time has elapsed, a failure signal of the pressure detection unit is generated, and when the discharge pressure Pt decreases to the set pressure P1, The operation is performed at the second low-speed frequency F2, and when the detected pressure reaches the unit stop pressure, the operation is returned to the preceding standby operation (preceding standby operation type) or the stopped state (intermittent trial operation type).

  As a result, it is possible to detect a clogging accident of the pressure detection unit and to prevent an accident that cannot be started in the event of a fire.

  In the operation mode D3, the electric on-off valve 101 is opened at regular intervals and the activation of the jockey pump 110 is prohibited, and the discharge pressure Pt does not decrease to the set pressure P1 set higher than the unit activation pressure after a certain period of time. In this case, when the failure signal of the pressure detection unit is generated and the pressure drops to the set pressure P1, the electric on-off valve is closed and the jockey pump 110 is started, and when the discharge pressure Pt becomes the unit stop pressure Pz. The jockey pump 110 is stopped.

  When this operation mode D3 is used, the jockey pump 110 is required, but since the pump 30 is not burdened with the auxiliary pressurizing function, the reliability of the unit is higher, and further, a clogging accident of the pressure detection unit is discovered, It is possible to prevent accidents that prevent starting up.

  As described above, according to the fire pump unit 10A according to the present embodiment, the same effect as that of the fire pump unit 10 described above can be obtained, and when the pressure tank 100 is further used, A clogging accident can be prevented in advance.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10,10A ... Fire extinguishing pump unit, 20 ... Pump apparatus, 30 ... Pump, 40 ... Electric motor, 50 ... Pump control apparatus (control part), 60 ... Inverter, 70 ... Control circuit, 80 ... Commercial frequency supply circuit, 90 ... Water discharge apparatus.

Claims (7)

An electric pump for pressure-feeding fire-fighting water;
An inverter for variable speed operation of an electric motor having a predetermined rated frequency for driving the electric pump;
A fire extinguishing pump unit comprising: a control unit that causes the inverter to perform a standby operation at a low frequency lower than a rated frequency of the electric motor.   The control unit detects a failure of the electric pump or the inverter, outputs a failure signal, and operates the motor at a rated frequency by the inverter when a start signal or a periodic inspection signal is input. The fire-extinguishing pump unit according to claim 1 characterized by things. An electric pump for pressure-feeding fire-fighting water;
An inverter for variable speed operation of the electric motor that drives the electric pump;
Test the motor at a low frequency every predetermined time from the stop state, and output a failure signal when a failure of the electric pump or the inverter is detected during the test operation, and stop the test operation when there is no failure abnormality A fire-extinguishing pump unit comprising: a control unit that operates the motor at a rated frequency when a start signal is input in any state during test operation or stop. Equipped with one of two types of electric pumps with a rated frequency of commercial frequency 50, 60 Hz,
In the inverter, a commercial operation circuit for supplying the commercial frequency is provided in parallel via an electromagnetic switch,
When the electric motor is driven by the inverter, the control unit stops the electric motor when detecting a failure of the inverter a predetermined number of times, and passes through the commercial operation circuit by the electromagnetic switch. The fire pump unit according to claim 1 or 3, wherein the electric motor is driven at the commercial frequency. A pressure tank for the sprinkler,
A pressure detector that detects the discharge pressure of the electric pump;
The control unit continuously or intermittently operates the electric pump at a first low-speed frequency lower than the rated frequency, and when the discharge pressure drops below a set pressure higher than a starting pressure, 4. The fire extinguishing according to claim 1, wherein the operation is performed at a second low-speed frequency higher than the low-speed frequency of 1 and when the discharge pressure becomes a stop pressure, the operation is returned to the standby operation or the stop state. Pumping unit. A pressure tank for the sprinkler,
It has a pressure detector that detects the discharge pressure,
An electric on-off valve provided in the drain portion of the pressure tank,
The control unit opens the electric on-off valve every predetermined time, and if the discharge pressure does not decrease to a pressure set higher than the unit start pressure after a certain time has elapsed, a failure signal of the pressure detection unit is generated. And when the discharge pressure is reduced to a pressure set higher than the unit starting pressure, the engine is operated at a second low speed frequency higher than the first low speed frequency and lower than the rated frequency, The fire-extinguishing pump unit according to claim 1 or 3, wherein when the discharge pressure reaches the unit stop pressure, the preceding standby operation or the stop state is restored. A pressure tank for the sprinkler,
A pressure detector for detecting the discharge pressure;
Jockey pump for auxiliary pressurization,
An electric on-off valve provided in the drain portion of the pressure tank,
The control unit opens the electric on-off valve every predetermined time and prohibits the activation of the jockey pump, and when the discharge pressure does not decrease to a pressure set higher than the unit activation pressure after a predetermined time has elapsed. When the failure signal of the pressure detection unit is generated and the discharge pressure falls to a pressure set higher than the unit start pressure, the electric on-off valve is closed and the jockey pump is started to discharge the discharge pressure. 4. The fire-extinguishing pump unit according to claim 1, wherein the jockey pump is stopped when the pressure reaches the unit stop pressure. 5.