JPH09261848A - Detecting circuit of suspension of cooling water supply of emergency diesel power generating installation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detecting circuit for suspension of cooling water of an emergency diesel power generating installation, which can prevent careless engine stop due to wiring disconnection of a flow switch. SOLUTION: This detection circuit is provided with a flow switch 69W having (a), (b) contacts whose one ends constitute common connection, an auxiliary relay X and an offdelay timer T whose exciting coils are connected in parallel, a flow switch auxiliary relay 69WX whose (b) contact is used for operation interlock, and a disconnection detection auxiliary relay Y. The common connection terminal of a flow switch 69W is connected with a control power source end P, and the (b) contact terminal is connected with the control power source end N via the parallel circuit of the exciting coils. The (a) contact terminal of the flow switch 69W is connected with the control power source end N via a series circuit of the (b) contact of the auxiliary relay X and the coil of the relay 69WX. A series circuit of the output contact Tb of a timer T, the (b) contact of the relay 69WX and the coil of the relay Y, and a series circuit of the (a) contact of the relay Y and disconnection display R are connected with the part between the control power source ends P and N.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention considers a cooling water breakage detection circuit used for detecting a cooling water breakage in an emergency diesel power generation facility and taking an emergency measure such as engine stop, especially a breakage in a detector wiring. The present invention relates to a cooling water cutoff detection circuit for an emergency diesel power generation facility.

[0002]

2. Description of the Related Art Cutoff of cooling water in an emergency diesel power plant is a serious failure and is an important interlock condition. Therefore, it is necessary to surely stop the engine when the cooling water is cut off, and a flow switch is provided to detect the cooling water cutoff. The flow switch has an output contact of a contact point and b contact point, and two types of circuit methods are considered.

One of them is, as shown in FIG. 2, an a contact 69W of a flow switch (water relay) 69W (represented by a symbol in the relay coil, hereinafter the same) between the control power source terminals P and N.
a (closed when water is cut off) and the series circuit of the coil of the auxiliary relay 69W1X are connected, and the b contact 69 of the auxiliary relay 69W1X is connected.
W1Xb is used for the driving interlock.

The other one is, as shown in FIG. 3, a series circuit of a b contact 69Wb of a flow switch (water relay) 69W (“open” when water is cut off) and a coil of an auxiliary relay 69W2X between control power terminals P and N. Connect the auxiliary relay 69W2X a
The contact 69W2Xa is used for the driving interlock.

[0005]

As described above, in the case of detecting the disconnection of the cooling water by using the flow switch, the disconnection of the switch wiring is detected in addition to the proper detection of the disconnection of the cooling water by the original operation of the flow switch. However, the same phenomenon as cooling water cutoff (similar result to cooling water cutoff detection) occurs, but in the case of flow switch wiring breakage, operation must be continued from an emergency duty. This is because the function of supplying cooling water is sound even if the wiring is broken, and the power generation equipment can be operated.

However, both of the circuit systems shown in FIGS. 2 and 3 have a problem in that respect. The problems are described below.

In FIG. 2, even if "cooling water cutoff" is detected in the state where the wiring is broken, the auxiliary relay 69W1X is not excited and the engine stop command is not issued, so that the temperature rise of the engine may be significant. . Further, even if the wiring is broken, it cannot be discriminated in normal operation. Therefore, a wire break will be found for the first time by inspection at the time when the engine is stopped due to an excessive temperature rise, resulting in increased damage at the time of power failure.

In FIG. 3, since the auxiliary relay 69W2X is deactivated and the engine is stopped even when the wiring is broken,
Although it is a fail-safe power generation facility, it will not be able to meet the requirement that it is necessary to continue operation except for "cooling water interruption" as an emergency duty.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above problems and to provide a cooling water disconnection detection circuit for an emergency diesel power generation facility which can prevent an inadvertent engine stop due to a wire disconnection.

[0010]

According to the present invention, there is provided a flow switch having an a contact and a b contact, one end of which is commonly connected, a water cutoff detection auxiliary relay having an exciting coil connected in parallel, an off delay timer, and an operation interface. A flow switch auxiliary relay that uses its b contact for locking and a disconnection detection auxiliary relay are provided, the common connection terminal of the flow switch is connected to one end of the control power supply, and the b contact terminal of the flow switch is connected to both of the above. The control is connected to the other end of the control power source through a parallel circuit of an exciting coil, and the a-contact terminal of the flow control switch is connected to the b-contact of the water cut detection auxiliary relay and the series circuit of the coil of the flow switch auxiliary relay to perform the control. It is connected to the other end of the power supply, and further, the output contact of the off-delay timer and the contact b of the flow switch auxiliary relay functioning as the contact b of the immediate operation time-delayed return. Wherein said that the series circuit and the series circuit of the disconnection detection auxiliary relay of a contact and break indicator with coils of wire breakage detection auxiliary relay connected between both ends of the control power supply and.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention. In the figure, 69W is an a contact 69Wa that is "closed" when the water is cut off.
A flow switch having a b-contact 69Wb becomes "open" in water outages, 69WX the auxiliary relay of the flow switch 69W, having a b-contact 69WXb _1, b _2. b contact 69
WXb ₁ is used for the driving interlock. X is a water interruption detection auxiliary relay, and has a b contact Xb. T is an off-delay timer, which has an output contact Tb for immediate operation time-delayed return. Y is an auxiliary relay for detecting wiring breakage of the flow switch 69W, and has an a contact Ya. The off-delay timer T considers the operation time and the recovery time of each relay,
Set the time limit appropriately.

The flow switch 69W has an a-contact 69
One end of Wa and b contact 69Wb are commonly connected to one terminal P of the control power supply, and the b contact terminal is connected to the control power supply through the parallel circuit of the coil of the water cut detection auxiliary relay X and the coil of the off-delay timer T. Is connected to the other terminal N. The a contact terminal of the flow switch 69W is connected to the b contact Xb of the water cut detection auxiliary relay X and the flow switch auxiliary relay 6
It is connected to the other terminal N of the control power supply via a 9 WX coil. The series circuit of the output contact Tb of the timer T, the contact b 69WXb ₂ of the flow switch auxiliary relay 69WX and the coil of the disconnection detection auxiliary relay Y is connected between the control power supply terminals P and N. A series circuit of the contact a Ya of the disconnection detection auxiliary relay Y and the disconnection indicator R is connected between the terminals P and N of the control power supply.

Next, the operation will be described. If the cooling water cutoff detection circuit is sound, the flow switch 69
A contact 69Wa of W is “closed”, b contact 69Wb is “open”
Becomes Therefore, the relay X is deenergized and its b-contact X
b is closed, and the flow switch auxiliary relay 69WX is energized. In other words, the cooling water cutoff is detected and the operation becomes the interlock.

In the case of wiring breakage, the broken spot is "B",
In the case of "C", the disconnection detection auxiliary relay Y is energized, and the operation of the disconnection indicator R indicates an abnormality (disconnection).
If the disconnection point is "a", the
After the setting of the off-delay timer T, the disconnection detection auxiliary relay Y is energized to display the disconnection.

[0015]

As described above, according to the present invention, the cooling water cutoff and the wiring breakage are detected separately, so that it is possible to prevent an accidental engine stop due to the wiring breakage. You can fulfill your duties as an emergency. Also, by knowing the wiring breakage of the cooling water breakage detection circuit,
This enables quick recovery measures before a serious failure occurs or engine stoppage, and the reliability of emergency diesel power generation equipment can be improved.

[Brief description of drawings]

FIG. 1 is a connection diagram showing one embodiment of the present invention.

FIG. 2 is a connection diagram showing one circuit system of a conventional example.

FIG. 3 is a connection diagram showing another circuit method of the conventional example.

[Explanation of symbols]

69W ... Flow switch 69Wa ... a contact of flow switch (“closed” when water is cut off) 69wb… b contact of flow switch (“open” when water is cut off) 69WX… Flow switch auxiliary relay (for interlock) R ... Disconnection indicator T ... Off-delay timer X ... Water breakage detection auxiliary relay Y ... Wire breakage detection auxiliary relay

Claims (1)

[Claims] 1. A flow switch having an a-contact and a b-contact, one end of which is commonly connected, a water cutoff detection auxiliary relay and an off-delay timer in which exciting coils are connected in parallel, and the b-contact is used for an operation interlock. A flow switch auxiliary relay and a disconnection detection auxiliary relay are provided, the common connection terminal of the flow control switch is connected to one end of the control power source, and the b contact terminal of the flow control switch is connected through the parallel circuit of both exciting coils. Connected to the other end of the control power supply, the a-contact terminal of the flow switch is connected to the other end of the control power supply through a series circuit of the b-contact of the water cut detection auxiliary relay and the coil of the flow switch auxiliary relay, Furthermore, the output contact of the off-delay timer, the contact b of the flow switch auxiliary relay, and the disconnection detection auxiliary relay, which function as the contact b of the immediate operation timed return And a series circuit of the disconnection detection auxiliary relay and a series circuit of a disconnection indicator are connected between both ends of the control power source.