JPS624616B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In indoor air conditioning control of a building, the present invention monitors whether the temperature inside the controlled room is maintained within the upper and lower limits depending on the operating conditions (heating/cooling),
The present invention relates to a temperature abnormality detection device for an air conditioner that detects an abnormality when the upper and lower limit ranges are exceeded.

Conventionally, the indoor temperature abnormality detection method for air conditioning control has been to set allowable upper and lower temperature limits for the target indoor temperature, and when the indoor temperature rises or falls below these upper and lower limits, it is detected as an indoor temperature abnormality.
I'm warning you.

However, when air conditioning control for buildings is targeted at office buildings, the amount of time the air conditioning equipment is operated during the day varies greatly depending on the number of hours of work and other factors. Also,
The time it takes for the indoor temperature to reach around the target set temperature after starting the air conditioner is affected by the difference between the temperature at the start of the air conditioner and the target temperature, and usually takes several tens of minutes to several hours. Furthermore, the target indoor temperature setting value differs throughout the year during the cooling season, the heating season, and the intermediate season when the seasons change.

Therefore, when detecting indoor temperature abnormality during air conditioning control, even if the indoor temperature deviates from the upper and lower limit set temperatures, the temperature should not be abnormal until the indoor temperature stabilizes around the target set temperature after the air conditioner is started.

Therefore, conventionally, the condition for activating the temperature abnormality detection means is that a certain period of time has passed after starting the air conditioner, or that the indoor temperature has reached a certain set value.

However, in the conventional method described above, the time required for the indoor temperature to reach a stable region and the set temperature are fixed by air conditioning control. Therefore, as the target temperature changes due to seasonal changes and the time to reach the target temperature changes,
If the time and temperature settings are not changed, the temperature abnormality detection means will be activated in a transient state before the target temperature is reached, and there is a drawback that it is likely to cause a malfunction in which it is determined that there is an abnormality even in a transient state.

In addition, in the conventional technology, since the time to reach the target temperature changes every day, in order to prevent the above-mentioned malfunction based on this, the time setting is set to a large value, and the start of the temperature abnormality detection means is delayed. There is a drawback.

An object of the present invention is to provide a temperature abnormality in an air conditioner that can automatically determine the transient region from the start of the air conditioner until the target temperature is reached, thereby starting an indoor temperature abnormality detection operation during air conditioning control as early as possible. To provide a detection device.

FIG. 1 shows a general indoor air conditioning control system. The temperature of the room 1 is the outside air 11 and the indoor intake air 10.
After filtering the dust with a filter 6, the cold and hot water flowing through the heat exchanger 5 cools the air conditioner during cooling and warms it during heating.
It is controlled to a constant value through the circulation of air supplied by the air supply 9.

Generally, when the amount of supply air 9 is constant, the thermometer 2
The manipulated variable for controlling the measured value to the target set temperature is the amount of cold and hot water that is supplied from the cold and hot water inlet 7 to the heat exchanger 5 and discharged from the cold and hot water outlet 8, and is controlled according to the temperature deviation. It is changing.

FIG. 2 shows the daily variation pattern of indoor temperature change during air conditioning control during cooling (curve) and heating (curve). In particular, air conditioners in office buildings must be operated during the required daytime hours (from time t ₀ to t ₂
(up to). Then, at startup in the morning, there is a transient region (from time t ₀ to t ₁ ) where the indoor temperature changes rapidly until the target set temperature 12 or 13 is reached.
and the stable region (time) after reaching the target set temperature.
(from t ₁ to t ₂ ).

FIG. 3 shows the vicinity of the transient region and stable region of the curve in FIG. 2 in detail.

The transient region from time t ₀ to t ₁ is the primary adjustment region (time t ₀ to t ₀₁ ), and a secondary adjustment region (from time t ₀₁
to t ₁ ).

If the indoor temperature falls within the control dead band width 15 due to the secondary adjustment, it becomes a stable region and the room temperature is maintained at a substantially constant level.

In the temperature abnormality detection device of the present invention, the point at which the transition region transitions from the primary adjustment region to the secondary adjustment region (hereinafter referred to as the secondary adjustment transition point) is determined from the rate of change of the temperature measurement value.

When the temperature measurement value reaches this secondary adjustment transition point, the alarm function is activated with the alarm upper and lower limit set values 16 and the alarm lower limit set values 17 as the alarm upper and lower limits, respectively. This enables early detection of temperature abnormalities in the stable region, and also enables alarm upper and lower limit band widths of 1
4 can be made narrower.

That is, in the present invention, when starting the air conditioner, in order to quickly bring the indoor temperature close to the target temperature, temperature control is prohibited and the machine is operated at full capacity, and temperature control is utilized only after the indoor temperature approaches the target set temperature. I'm taking it. As a result, temperature abnormalities can be detected quickly, especially in computer rooms, etc., which have strict tolerances for indoor temperature setting fluctuations, and stable operation of important equipment such as computers can be achieved.

FIG. 4 shows an embodiment of the present invention. Figure 4 1
11 are the same as in FIG.

The secondary adjustment transition detection circuit 20 starts operating in response to the operation signal of the air conditioner fan 4 indicating the start of the air conditioner, operates the start-up operation prohibition command section 20A,
A signal INH that prohibits the operation of the temperature abnormality detection means is supplied to the alarm comparison circuit 21, and the air conditioner is operated at full capacity ignoring the temperature control function. The secondary adjustment transition detection circuit 20 executes temperature control by adjusting its capacity in accordance with the deviation of the room temperature from the target set temperature so as to reduce the deviation to zero. The time change of the temperature measurement value T from the indoor thermometer 2 is captured.
Then, the secondary adjustment transition point (time
The temperature inflection point at t ₀₁ ) is detected by, for example, differentiation in the indoor temperature inflection point detection section 20B. The detection signal is input to the alarm comparison circuit 21 as a trigger signal S for starting the alarm function.

On the other hand, the switching signal S/W of the cold/hot water switching circuit 18 is input to the alarm upper/lower limit selection circuit 19 . Depending on the switching signal, either one of the cooling alarm upper and lower limits T _SH , T _SL and the heating alarm upper and lower limits T _WH T _WL is selected, and the resulting alarm upper and lower limits T _H , T _L are selected. The signal is input to the alarm comparison circuit 21.

The alarm comparison circuit 21 compares the alarm upper and lower limits T _H ,
The difference between T _L and the temperature measurement value T from thermometer 2 is compared. Then, the temperature measurement value T is the alarm upper and lower limit value T
If it exceeds or falls below _H and T _L ,
The alarm output circuit 22 outputs a temperature abnormality alarm.

FIG. 5 shows processing blocks when the present invention is implemented on a computer. Block 23
Now, the signal from the hot and cold water switching circuit 18 shown in FIG. 4 is taken in, and in block 24, the switching signal is changed to
Or determine whether the water is hot.

In the case of cold water, the cooling alarm upper and lower limits T _SH and T _SL are selected as the alarm upper and lower limits T _H and T _L in block 25, while in the case of hot water, the heating alarm upper and lower limits T _WH are selected in block 26. , T _WL is the alarm upper and lower limit value T _H ,
selected as T _L.

Next, in block 27, the measured indoor temperature value T _i
(measured value at time i) is captured. Temperature measurement value T at time i and time (i-1) which is the previous capture time
Using _i-1 , calculation of temperature gradient ΔT _i is performed in block 2.
It will be held at 8. Equation (1) is the calculation formula.

ΔT _i = T _i -T _(i-1) / Δt (1) where, T _i : Temperature measurement value at time i T _(i-1) : Temperature measurement value at i-1 time Δt : Time interval Block 29 is a process of determining the secondary adjustment transition point from the primary adjustment area to the secondary adjustment area in the above-mentioned transient area from the inflection point of the temperature gradient, and is determined based on the condition of equation (2).

|ΔT _(i-1) |≧|ΔT _i | (2) In other words, when the condition of equation (2) is not satisfied,
Jump to end 32. On the other hand, when the condition of equation (2) is satisfied, it is assumed that the inflection point has been reached, and in the next block 30, the upper and lower alarm limits of the current measured value T _i are determined according to equation (3). If the current measured value T _i does not satisfy the condition of equation (3), it is considered as an abnormality of the upper and lower temperature limits.
In block 31, an alarm is output to the outside.

T _L <T _i <T _H (3) Where, T _L : Alarm lower limit value T _H : Alarm upper limit value According to the present invention, an unnecessary temperature abnormality alarm is generated when there is a transient temperature change during operation of the air conditioner. In addition, the alarm upper and lower limits of the target temperature set value can be automatically switched according to cooling/heating switching, so there is no need to reset the alarm upper and lower limits throughout the year, and the alarm is only activated during temperature stability control. By activating the function, the setting range of the upper and lower alarm limits can be narrowed, making it possible to detect temperature abnormalities at an early stage.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a general air conditioner, Fig. 2 is a diagram showing a temperature change pattern in a controlled room, Fig. 3 is a partially detailed diagram of Fig. 2, and Fig. 4 is an embodiment of the present invention. FIG. 5 is a flowchart when the present invention is implemented on a computer. 1...Indoor, 2...Thermometer, 4...Air conditioner fan, 5
...Heat exchanger, 18...Cold/hot water switching circuit, 19...Alarm upper/lower limit selection circuit, 20...Secondary adjustment transition point detection circuit, 21...Alarm comparison circuit, 22...Alarm output circuit.

Claims (1)

[Scope of Claims] 1. An air conditioner fan that supplies hot and cold air into a controlled room, means for measuring the temperature in the room, means for setting upper and lower alarm limits for the room temperature, and There is a temperature abnormality detection means that generates an alarm when it deviates from the lower limit band, a means for prohibiting the operation of the temperature abnormality detection means at the time of startup, and a means that operates at full capacity at the time of start-up and when the indoor temperature falls within the alarm upper and lower limit bandwidth. A temperature abnormality detection device for an air conditioner is equipped with a means for controlling the capacity according to a deviation of the indoor temperature from a target set temperature, and a change rate detection means for detecting a change rate of the indoor temperature at the time of startup. and an inflection point detection means that generates an output when the rate of change decreases, and a means for activating a temperature abnormality detection means based on the output of the inflection point detection means. Temperature abnormality detection device. 2. The temperature abnormality detection device for an air conditioner according to claim 1, wherein the setting of the upper and lower alarm limit bands is automatically switched in conjunction with switching between heating and cooling.