FI107414B - Fire alarm - Google Patents

Description

107414

Fire alarm

The present invention relates to a fire detector for measuring and reporting physical quantities of heat, smoke, etc. caused by fire ignition, and more particularly to detecting fire ignition with high accuracy using the membership function.

In a typical fire alarm, a smoke sensor and a heat sensor are placed in each control area, and the absolute values or change values of the physical quantities of the substances caused by the fire (heat, smoke, etc.) are detected by these sensors to detect the fire. In other words, it is determined that the fire has been ignited by comparing the information obtained from the sensors to a preset threshold.

However, the measured values observed with such a conventional fire alarm with a temperature sensor and a smoke detector represent the amount of heat and smoke accumulated in the control area. Therefore, these values do not directly reflect the origin of the fire in the laa-15.

Thus, the detection result of a conventional fire alarm does not clearly indicate whether the measured values have been obtained from a large fire or if the amount of heat accumulated is large, although the extent of the fire is not so large. Therefore, the extent and location of the onset of a fire are not fixed criteria when deciding whether to ignite a fire and thus it is impossible to give 20 alarms based on the actual fire situation.

The Applicant provides a fire alarm, such as PCT / JP90 / 00062 (Named Countries: AT, AU, DE, FI, GB, US), which calculates the extent of the beginning of the fire and thereby performs the fire configuration.

Further, if a person truly encounters a fire, he or she will empirically evaluate the degree of risk of the fire and act depending on the degree of danger. Accordingly, the content of the alert should be related to the degree of danger, taking into account means of escape.

The object of the present invention is to provide a fire alarm which is capable of evaluating a fire based on the actual fire situation and providing an alarm depending on the degree of danger that a person would know regarding the extent, location, etc. of the fire.

The object of the invention is achieved by the means set forth in the claims.

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To accomplish this object, the fire alarm of the present invention comprises a detector 1 for detecting physical quantities that increase upon fire ignition, such as changes in temperature, smoke density, evolved gas density, and barometric pressure, and a precursor to reset the membership functions such as the rate of heat release, the rate of smoke generation, and the value of gas calculated by the quantities, and the degree of danger a person would know about such a value, and the degree of hazard to physical quantities using membership functions to provide an alarm according to the degree of hazard.

It also includes a detection device for detecting physical quantities in the event of a fire and for providing analogue data. It further comprises a hazard computing device for pre-setting membership functions that represent the correlation between the analog value obtained by detecting said physical quantities and the hazard degree that a person would be aware of with respect to said analog value, and computing a hazard rank provided by said detector. analog value using said membership functions.

According to a fire alarm having such a structure, since fire ignition is estimated and the degree of danger is obtained by using membership functions, a result similar to human evaluation can be obtained. Therefore, it is possible to give a very accurate 20 and proper fire alarm.

Further, the fire alarm effectively reduces false alarms.

Fig. 1 is a structural view of a fire alarm according to an embodiment of the present invention; Fig. 2 is an explanatory view showing an example of a membership function regarding the heat release rate to be set in the hazard computation portion of the device; and Fig. 3 is an explanatory view showing an example of a membership function regarding the rate of formation to be set in the hazard computation portion of the device.

A preferred embodiment of the invention will now be described with reference to the drawings.

The construction of the fire alarm of the embodiment will first be described with reference to Figure 1. · Detector devices la-In, such as heat sensors and smoke sensors, detect physical quantities of substances, such as temperature, smoke density and gas density, which increase upon ignition. One monitoring device or several devices are located in each control area.

The output signals of the detection devices Ia-In are applied sequentially in time to the hazard section 5 calculation section 3 along the transmission line 2 by scrolling through the consecutive detection devices Ia-In in a predetermined period.

Hazard Calculation Part 3 includes membership functions that represent a rising value per time unit, such as heat release rate, smoke rate, and gas value, calculated by physical quantities of 10 increasing in the event of a fire, and the degree of danger that a person would know. , relationship, or membership functions in the form of a lookup table. Hazard Calculus 3 calculates hazard values from data based on the signal values transmitted from the detectors la - In according to membership functions and the like, and transmits the data to the fire estimation part 4. numerical values or functions by statistical processing.

The hazard assessment section 4 compares a plurality of preset thresholds with the hazard level data input from the hazard calculation section 3 and estimates the fire ignition 20 based on the relationship between the threshold values and the data. If it is estimated that a fire has been ignited, the hazard assessment section 4 determines the type of alarm and transmits the alarm signal to the various alarm devices and fire extinguishers via the alarm output section 5.

Figure 2 illustrates a membership function which illustrates the degree of danger that a person 25 would feel with respect to the rate of heat release of an object in the event of a fire. In other words, the horizontal axis indicates the rate of heat release Qf [kW] of the burning object, which corresponds to the extent of the fire, and the vertical axis indicates the degree to which the person would be at risk of the rate of heat release (hazard degree Df). Assuming a hazard level of 1.0 for a person in danger, the hazard membership function 30 is formed by statistically treating the ratio of persons in danger when the heat release rate Qf is lower than the release rate of the above state.

Membership functions thus obtained experimentally, or data corresponding to function ·. The hazard calculator 3 searches 4 107414 for the heat release rate Qf based on the signal transmitted from the sensors la to the thermal sensor, calculates the hazard rate Df based on the heat release rate Qf, and transmits the hazard Df to Fire Evaluation Section 4.

On the other hand, Figure 3 shows the membership function for the smoke generation rate 5 obtained in the same manner as in Figure 2. The hazard level is determined based on the amount of smoke by pre-setting the membership function for the smoke generation rate Qs shown in Figure 3 into the hazard ratio calculation section 3. In other words, the membership function shown in Fig. 3 is obtained by converting the ratio of several persons who would be at risk for the smoke generation rate Qs [g / s] when burning, for example, "kotatsua" (burning article A) and "tatami" (burning article B). Ds to numeric values.

The hazard computing part 3 searches for the smoke generation rate Qs based on a signal representing the smoke density transmitted from the detectors la-in to the inlet sensors in the same way as for the heat release rate, and renders the hazard rate Ds corresponding to the smoke generation rate Q

When the data representing the hazard output signal from the hazard calculation section 3 is input to the fire estimation section 4, it is compared to the predefined threshold values in the fire estimation section 4. Alarm data according to the comparison result is the output signal of several preset data. For example, in Figs. 2 or 3, if both degrees Df and Ds are less than 0.5, it is estimated that an incipient fire has occurred, the pre-alarm being given to the guard room to send a rescue message. On the other hand, if both degrees Df and Ds are greater than 0.5, it is estimated that the fire has been expanded, all alarms in the building are triggered and a control action is taken to operate a fire suppression device such as a fire door.

25 The level of danger for pre- and main alarms can be changed depending on the operating conditions in the room.

According to the embodiment described above, since fire ignition is detected and the degree of danger is obtained by using membership functions, an evaluation result equal to a human estimate of fire can be obtained, and an accurate and appropriate fire alarm 30 can be performed.

The above evaluation process for fire evaluation section 4 is given as an example. Therefore, it is possible to deal with the degree of danger Df obtained from. the membership function for the rate of heat release, and the degree of danger Ds obtained based on the membership function for the rate of smoke generation, in combination conditions. Further, various processes can be performed, for example, the second degree of danger Qf or Qs has priority over the other in order to evaluate the fire situation and so on.

Although the membership functions for the heat release rate and the smoke generation rate of the physical quantities are formed and the degree of hazard is formed according to the membership functions in the above embodiment, other physical quantities, such as a change in atmospheric pressure or the like, may be used. In addition, it is also possible to form a membership function with respect to the analogue output signals of the detectors to provide a degree of hazard.

Claims (2)

6 107414 A fire alarm for evaluating a fire ignition and for providing an alarm, characterized in that it comprises a detector (1a - In) for detecting physical quantities generated in the event of a fire, for presetting a hazard calculator (3) for membership functions which increment in time, for example, the correlation between the rate of heat release, the rate of smoke generation and the value of gas calculated by said physical quantities, and the degree of danger a person would feel about said rising value, and the degree of hazard relative to said rising value calculated by said physical sum means detected by said detector, using said membership functions, and fire detector (4) for determining the type of alarm depending on said degree of danger. 2. A fire alarm for evaluating fire alarms and for providing an alarm, characterized in that it comprises a detector (la-in) for detecting physical quantities generated in the event of a fire and for providing analog data, presetting the hazard calculator (3) for the value of the formed by detecting said physical quantities and correlation between the degree of danger a person would know with respect to said analog value and the degree of danger with respect to said analog value generated by said detection device using said membership functions, and a fire estimator (4) for determining the type of alarm depending on said degree of danger. 7 107414