JP2691256B2 - Pump parallel operation control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for controlling parallel operation of pumps, and by organically connecting a plurality of pumps, an internal combustion engine and a generator, the rotational speeds of the plurality of pumps can be controlled. The present invention relates to a parallel operation control method for pumps that can be controlled at substantially the same speed all at once.

[0002]

2. Description of the Related Art Large-scale painting equipment, fountain equipment and the like often require constant speed control of a plurality of pumps operating in parallel. In such a case, normally, as shown in FIG. 2, the input frequency F to the drive motor M of the pump is adjusted by using the inverter speed control device A, whereby the rotation speed of each pump P is simultaneously changed to a desired rotation speed. I try to control the number. However, in the system using the inverter speed control device as shown in FIG. 2, the inverter speed control device itself is expensive, so that the pump equipment cost cannot be significantly reduced. Further, since the power source C normally uses the electric power supplied from the electric power company, the running cost of the pump facility is relatively high. Further, when hot water or the like is required, it is necessary to separately install a boiler or the like, which causes a problem that the equipment cost increases.

[0003]

SUMMARY OF THE INVENTION The present invention has the above-mentioned problem in the conventional pump parallel operation control method using an inverter speed control device, that is, the cost of the pump equipment is reduced because the inverter speed control device is expensive. Is difficult,
Since power purchase is used as a power source, it is intended to solve problems such as running cost being relatively high.By organically connecting an internal combustion engine, an AC generator and a plurality of pumps, A stable parallel operation control method for pumps and a parallel operation control method for pumps capable of significantly reducing pump equipment costs and running costs are provided.

[0004]

According to the present invention, an internal combustion engine E, an AC generator G and one of a plurality of pumps P are coaxially connected to each other so that the internal combustion engine E and the AC generator G together. ,
A pump driving motor M is directly connected to each of a plurality of other pumps P, power generated by an AC generator G is supplied to each pump driving motor M, and the rotational speed of the internal combustion engine E is changed to generate AC power.
By changing the rotation speed of the rotor of the machine G, the frequency of the generated power is changed to control the rotation speed of the plurality of pump driving motors M driven by the generated power to a desired rotation speed.
It is an basic configuration of the invention that that.

[0005]

By the operation of the internal combustion engine E, one pump P and the AC generator G are rotated at a predetermined rotation speed. Further, the electric power generated by the AC generator G is supplied to the pump driving motors M of the other plurality of pumps, whereby each pump driving motor M is rotated at substantially the same speed as the AC generator G. When the rotation speed of the internal combustion engine E is changed, the frequency of the electric power generated by the AC generator G is changed, so that the rotation speed of each pump driving motor M is changed in proportion to the rotation speed of the internal combustion engine E. In this way, by adjusting the rotation speed of the internal combustion engine E, the rotation speeds of the plurality of pumps P are controlled to the same rotation speed all at once. The exhaust heat of the internal combustion engine itself and the heat in the exhaust gas are recovered by the cooling water 1 to obtain hot water.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall system diagram of a pump facility adopting the present invention. In the figure, E is an internal combustion engine, G is a three-phase AC generator, M is a pump driving generator, P is a pump, and H is exhaust gas heat. The exchanger, W is cooling water. As the internal combustion engine E, a so-called cylinder jacket Eb is used as a diesel engine, and cooling water W is circulated in the cylinder jacket Eb. Further, the internal combustion engine E is coaxially connected to a three-phase AC generator G described later and one of the plurality of pumps P. That is, the drive shaft Ea of the internal combustion engine E
Is directly connected to one end of the rotor shaft Ga of the three-phase AC generator G,
Further, the other end of the rotor shaft Ga is directly connected to the drive shaft Pa of one pump P, and the three-phase AC generator G and one pump P are rotationally driven by the internal combustion engine E at the same speed. .

In this embodiment, the internal combustion engine E
Output 50 ~ 200PS, rotation speed 1000 ~ 200
A 0 RPM variable speed diesel engine is used, and the generated power is one pump P and three-phase AC generator G.
It is consumed to drive the rotation of the.

The exhaust gas 1 of the internal combustion engine E is discharged into the exhaust gas heat exchanger H, where the cylinder jacket E
Heat is exchanged with the cooling water W flowing through the inside of b. As a result, heat is recovered from the internal combustion engine body and exhaust gas, and hot water is obtained.

The three-phase AC generator G supplies electric power to the respective pump drive motors M of the other plural pumps, and in the present embodiment, can supply electric power to the three motors M. It has a capacity. Further, the frequency of the electric power generated by the three-phase AC generator G changes to an appropriate frequency by changing the rotation speed of the internal combustion engine E. In the present embodiment, a four-pole AC generator is used. When the rotation speed of the internal combustion engine E is rated (1800 RPM), 60 Hz three-phase AC is generated, and when the rotation speed of the internal combustion engine E is 1000 RPM. Generates 33 Hz three-phase AC power. Further, it goes without saying that the power generated by the AC generator G is kept at a constant voltage value by adjusting the field current and the like.

Each of the pump driving electric motors M is directly connected to each driving shaft Pa of the pump P. In this embodiment, three pump driving motors M having four poles and three-phase induction motors of the same capacity are used. It is used. As a result, when the rotation speed of the internal combustion engine E is 1800 RPM, the frequency of the electric power generated by the generator G is 60 Hz, and the rotation speed of each pump driving motor M is about 1750 RPM (slip S≈0.3).

In this embodiment, the pump driving motor M is used.
As a three-phase induction motor is used as
Although there is a slight difference in the number of rotations between one pump P that is driven more and a plurality of other pumps P that are driven by the pump driving motors M, there is no particular problem in practical use. Further, when a synchronous motor is used as the pump driving motor M, it goes without saying that the rotational speed difference becomes zero.

As the pump P, a pump having the same capacity and the same type is used, and the water from the suction line 2 is pressurized to a predetermined pressure and supplied to a predetermined location through the discharge line 3. In this embodiment, the water film for so-called paint atmosphere shielding is formed by sending pressurized water from the four pumps P to the coating booth, and the discharge line 3 is independently drawn from each pump P. However, it goes without saying that they may be connected to a common discharge pipe (not shown). Further, in the present embodiment, the capacities of the pumps P and the motors M are the same, but it goes without saying that there may be a capacity difference between the pumps and the motors M.

Next, a parallel operation control method for pumps according to the present invention will be described. First, the internal combustion engine E is operated and its rotation speed is set to a predetermined rotation speed (for example, 1800 RP).
Adjust to M). By the operation of the internal combustion engine E, a generator G is transmitted through a transmission S such as a speed increaser or a speed reducer when necessary.
And one pump P is rotationally driven at a predetermined rotation speed.
When the generator G is driven, AC power of a predetermined frequency and a predetermined voltage is generated by adjusting the exciting current and the like, and is supplied to each pump driving motor M. As a result, each pump driving motor M is rotated at a speed substantially equal to that of the generator G, whereby the other plurality of pumps P are rotationally driven at substantially the same speed as the generator G.

When the rotational speed of the internal combustion engine E is adjusted to reduce its rotational speed (for example, to 1000 PPM), the frequency of the electric power generated by the generator G decreases (for example, 6).
0 Hz to 33 Hz), which causes the rotation speed of the pump drive motor M to decrease (for example, from about 1750 RPM to 970 RPM). In this way, a plurality of pumps P
By adjusting the rotation speed of the internal combustion engine E,
The rotation speed of the generator G is controlled to be almost the same as that of the generator G all at once.

The exhaust heat of the internal combustion engine E and the combustion exhaust gas 1 is recovered by the cooling water W to obtain hot water.

[0016]

According to the present invention, by adjusting the rotation speed of the internal combustion engine E, the rotation speeds of a plurality of pumps can be simultaneously changed to a desired rotation speed without using an expensive inverter speed control device. Therefore, the equipment cost can be reduced as compared with the conventional pump equipment using the inverter speed control device. Further, since the power generated by the internal combustion engine E is used as the drive energy of the pump equipment, the running cost of the pump equipment can be reduced and the exhaust heat can be recovered as compared with the case where the so-called power purchase is used as the energy source. The energy utilization rate is greatly improved. Further, the capacity of the AC generator G may be the capacity obtained by subtracting the capacity of one pump P, and the generator capacity can be reduced. As described above, the present invention has excellent practical utility.

[Brief description of the drawings]

FIG. 1 is an overall system diagram of pump equipment used in a parallel operation control method for pumps according to the present invention.

FIG. 2 is an overall system diagram showing a conventional parallel operation control method for pumps.

[Explanation of symbols]

E is an internal combustion engine, Ea is a drive shaft, Eb is a cylinder jacket, H is an exhaust gas heat exchanger, G is an AC generator, Ga is a rotor shaft, M is a pump drive motor, Ma is a motor drive shaft,
P is a pump, Pa is a pump drive shaft, W is cooling water, 1 is exhaust gas, 2 is a water absorption line, and 3 is a discharge line.

Claims (3)

(57) [Claims] 1. An internal combustion engine (E), an alternating current generator (G) and one of a plurality of pumps (P) are coaxially connected to each other, and the internal combustion engine (E) is used to generate an alternating current generator (G). ) And one pump (P) are coaxially rotationally driven, and the pump driving motors (M) are directly connected to the plurality of other pumps (P) to generate electric power of the AC generator (G). By supplying power to the drive motor (M) and changing the rotation speed of the internal combustion engine (E)
By changing the rotation speed of the rotor of the AC generator (G)
Ri, driven by the generated electric power by changing the frequency of the power generated
A plurality of Tokoro the rotational speed of the pump driving motor (M) to be
Parallel operation control method for pumps characterized by controlling to a desired rotation speed 2. The internal combustion engine (E) is provided with a cylinder jacket (Eb), and the exhaust gas (1) from the internal combustion engine (E) is introduced into the exhaust gas heat exchanger (H), and the cylinder jacket (Eb) is opened. The parallel operation control method for pumps according to claim 1, wherein the circulating cooling water (W) is heated by the exhaust gas (1) in the exhaust gas heat exchanger (H). 3. An AC generator (G) and a pump (P) are driven through a transmission (S), and a pump driving motor (M) has the same number of poles as the AC generator (G). A parallel operation control method for a pump according to claim (1) or (2), which is an induction motor.