JP3113528B2 - Waste heat utilization equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for utilizing waste heat discharged from a factory, and particularly to a drive power of a motor driven by a commercial power supply and a drive force of a turbine driven by the waste heat. The present invention relates to a method of driving a load in a waste heat utilization facility that drives a load such as a compressor or a pump.

[0002]

2. Description of the Related Art In many cases, when waste heat generated in a factory is used effectively, steam is generated by a boiler using the waste heat, and a generator driven by a turbine driven by the steam is often used. However, in this case, when the energy conversion efficiency is low and the amount of waste heat is relatively small, there is a case where the load is driven directly by the turbine and the power shortage by the turbine is compensated by the power of the motor driven by the commercial power supply. FIG. 3 is a circuit diagram showing such waste heat utilization equipment. In this case, a turbine T, a motor M driven by a commercial power supply, and a compressor C, which is an example of a load, are connected by a single shaft. In this figure, a clutch CL is provided between the turbine T and the motor M. In this conventional facility, steam from a boiler 1 that generates steam with exhaust gas from a waste heat generating facility of a factory is supplied to the turbine T via a flow control valve B. In such a facility, the driving energy of the turbine T fluctuates according to the fluctuation of the amount of waste heat, as represented by a curve T in FIG. 4, for example. On the other hand, the required power of compressor C, which is the load, is also shown in FIG.
In the curve C of FIG. Therefore, when the required power of the compressor C exceeds the curve T, the shortage of the driving energy by the turbine T can be compensated only by the motor output M as shown in FIG. , The motor M is driven without load due to the excess power of T1, which is the difference from the turbine power T. This means that the motor M generates power, which is a problem in handling the motor. Therefore, conventionally, as shown in FIG. 3, a tachometer G for detecting the number of rotations is provided in the turbine T, and the turbine T
When the rotation of the turbine becomes excessively high, the amount of steam supplied to the turbine T is adjusted to reduce the turbine output in accordance with the decrease in the load. FIG. 2 shows the turbine T and the load C when the output control of the turbine is normally performed.
FIG.

[0003]

As described above, in the prior art, a decrease in load is detected based on the number of rotations of the turbine. However, a change in the number of turbines due to a change in the load is small when viewed from the entire turbine speed. Yes (for example, 3540-3
There is a problem that the detection accuracy cannot be increased because the output fluctuation from the tachometer is small. An object of the present invention is to provide waste heat utilization equipment with high detection accuracy in order to solve such problems in the conventional technology.

[0004]

To achieve the above object, the present invention provides a turbine driven by using waste heat discharged from a factory, a motor driven by a commercial power supply,
In a waste heat utilization facility in which a load is connected with a single shaft and the load is driven by the driving force of the turbine and the motor, the load is provided in a power supply circuit between the motor and a commercial power supply .
Is, an ammeter for detecting a current flowing in the power supply circuit is provided to detect a more state of the motor to the current value,該Mo
The waste heat utilization equipment is characterized in that the amount of steam flowing into the turbine is controlled before the data enters a power generation state .

[0005]

According to the present invention, the load that is being handed down turbine output is detected by an ammeter provided in the driver circuit between the motor and the commercial power supply. Such an ammeter has zero output when the load and turbine output are balanced,
Since the current value which fluctuates greatly on both sides can be detected, the detection accuracy is much improved as compared with the detection by the tachometer in the prior art , and the motor is used as a generator.
Since the turbine power is limited before it operates, the motor starts.
Avoid adverse effects on commercial power by operating as an electric machine
I can .

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. The following embodiment is an example embodying the present invention and is not intended to limit the technical scope of the present invention. FIG. 1 is a circuit diagram of the waste heat utilization equipment according to one embodiment of the present invention. In the figure, the same reference numerals are used for the elements common to those of the prior art shown in FIGS. In the embodiment shown in FIG. 1, unlike the conventional circuit shown in FIG. 3, the tachometer G for detecting the number of revolutions of the turbine T is omitted, and a current is supplied to the drive circuit between the motor M and the commercial power supply. The meter A is inserted, and based on the output signal from the ammeter A , the flow control valve B is driven before the motor M shifts to the generator state, and the amount of steam supplied to the turbine T is adjusted. Thereby the load is lower than the output of the turbine T
Immediately before, the output of the turbine T decreases. That is, it is possible to avoid the disadvantage that the turbine T is always operated with an output that does not exceed the load, the motor M generates power, and adversely affects the commercial power supply .

[0007] ammeter A as described above, measures the current for driving motors, motors M chooses filter type to measure the previous current becomes the power generation state. If the rotation of the turbine T is controlled after the motor M starts generating power, the delay of the response of the turbine T causes the power generation of the motor M to be performed for a long time, which is inconvenient.
In the above embodiment, the case where the compressor is used as the load has been described. However, this is an example, and any equipment having a variable load, such as a pump or an air conditioner, is applicable.

[0008]

According to the present invention, the load reduces the turbine output .
It is detected by the ammeter provided in the drive circuit of the motor that is being handed down. Such a current meter may detect the current value greatly varies on both sides and 0 output when the load and the turbine output is balanced, it is possible to maintain a high detection accuracy. The motor is used as a generator
Since the turbine power is limited before it operates, the motor starts.
It is said that the operation of electric motors has a negative effect on commercial power.
Can solve serious problems.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a waste heat utilization facility according to one embodiment of the present invention.

FIG. 2 is a graph showing output fluctuations of a turbine, a motor, and a load when the amount of steam supplied to the turbine is adjusted normally.

FIG. 3 is a circuit diagram of a conventional waste heat utilization facility.

FIG. 4 shows a turbine for explaining a problem of the present invention;
4 is a graph showing output fluctuations of a motor and a load.

[Explanation of Signs] 1. Boiler A. Ammeter T. Turbine M. Motor B. Flow control valve C. Load (compressor)

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Namagawa 2-1-1, Taoyuan, Ikeda-shi, Osaka Inside Daihatsu Industry Co., Ltd. (56) References JP-A-62-268382 (JP, A) JP-A Sho 63-148883 (JP, A) JP-A-63-71503 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01K 13/00 H02P 7/00 F01D 15/10 F01K 23 / Ten

Claims (1)

(57) [Claims] 1. A turbine driven by using waste heat discharged from a factory, a motor driven by a commercial power supply, and a load are connected by a single shaft, and the load is controlled by a driving force of the turbine and the motor. In the waste heat utilization equipment that is driven, it is installed in the power supply circuit between the motor and the commercial power supply.
An ammeter for detecting a current flowing in the power supply circuit is provided, more it detects the state of the motor to the current value, the motor power generation
Waste heat utilization equipment characterized in that the amount of steam flowing into the turbine is controlled before the state is reached.