JPH0676855B2 - Heat source device control method and device - Google Patents

Description

The present invention relates to a heat source device for air conditioning, freezing, etc., and more particularly to a control device suitable for controlling the capacity of a compressor using an inverter.

[Conventional technology]

The conventional device compares the set value by the capacity setting means and the detected value by the load state detecting means, for example, as described in Japanese Patent Publication No. 59-34935, and responds to this deviation when the deviation is larger than a predetermined value. When the output is smaller than a predetermined value, the motor is started and stopped with a predetermined hysteresis width.

[Problems to be Solved by the Invention]

In the above-mentioned conventional technology, since the output is a primary system with respect to the deviation, the response time which affects the refrigeration cycle and the load after the output changes is not considered, and the deviation change is output as it is. Therefore, it was insufficient in terms of control stability including disturbance and comfort.

An object of the present invention is to provide a control device for a heat source device that can improve control stability and realize comfortable air conditioning.

[Means for Solving the Problems]

The above object is to provide a refrigeration cycle formed by a compressor for compressing a refrigerant, a heat exchanger for each of a condenser and an evaporator, and an expander for a refrigerant, a motor for driving the compressor, and power supply to the motor. In a method of controlling a heat source device by controlling an output voltage and an output frequency from the inverter of the heat source device having an inverter,
The set value of the capacity setting means and the detected value of the load state detecting means are fetched at every predetermined sampling time, these deviations are calculated, and a term proportional to the deviation and a temporal change amount of the deviation are mainly used. The correction amount calculated by the arithmetic expression consisting of the sum of the terms and the term is added to the previous calculated value, and when this calculated value is larger than the predetermined value, this calculated value is output to the inverter to operate the motor, and this calculated value is When it is smaller than a predetermined value, the motor is stopped without outputting to the inverter, and when the deviation between the set value by the capacity setting means and the detected value by the load state detecting means becomes a certain value or more, the motor is calculated by the above-mentioned arithmetic expression. Achieved by starting with a value.

[Action]

When operating at the frequency calculated by the above method, it becomes possible to control at each sampling time decided considering the change of the refrigeration cycle and the influence of the load, and it is stable against external disturbance because it takes into consideration the temporal change. It becomes control. In addition, since the machine can be operated at the lowest frequency for as long as possible even under a light load, frequent start and stop of the machine are reduced, and reliability and comfort of the apparatus are increased.

〔Example〕

An embodiment of the present invention will be described below. FIG. 1 shows an overall configuration diagram of the present invention. 1 is ability setting means, 2
Is a load detecting means. Reference numeral 3 denotes an arithmetic device which has a role of taking in the set value by the capacity setting means and the detected value by the load detecting means at every predetermined sampling time, and calculating the frequency based on this. An inverter 4 is configured to control the number of revolutions of the motor 5 and the compressor 6 in accordance with the frequency output from the arithmetic unit to control the capacity of the refrigeration cycle 7. The refrigeration cycle 7 is composed of, in addition to the compressor 6, heat exchangers for the condenser section and the evaporation section, an expansion section for refrigeration, and the like.
Not disclosed here. The detailed operation will be described with reference to the flow chart of FIG.

When a power supply (not shown here) is turned on and a driving operation is performed, the arithmetic unit performs initialization (memory clear or initial setting) before starting control, and prepares for control. This process is the process of F5. Next, the set value Ta by the capacity setting means 1 and the detected value by the load detecting means 2 are read. This process is the process of F10. Next, at F15, the difference ΔT ₁ (= Ta−T _S ) from this read value
Ask for. Then, in F20 and F25, when this ΔT ₁ is less than ΔT _11, Hz = min (F30). And when ΔT is ₁₁ or more, H
Set z = ₁ ( ₁ > min) (F35). Further, at the time of starting, since there is only the value that has been taken in for the first time, the frequency value is calculated assuming that the previous value ΔT ₀ is equal to the current value ΔT ₁ . The formula is ΔHz = {K _P × ΔT ₁ × t _S + Ki (ΔT ₁ −ΔT ₀ )} Hz ……
(1) Hz = Hz + ΔHz (2) The first term of the equation (1) is mainly proportional to the difference between the set value and the detected value, and is deeply related to the sampling time t _S. The second term is a term mainly composed of the temporal change of this difference. The formula for calculating the final frequency is calculated by adding the Hz previously determined using the formula (2) and this ΔHz. In processing F50, it is compared whether or not this calculated value exceeds min,
When it exceeds, the inverter 4 and the motor 5 are driven by the Hz calculated in F55 to operate the compressor. afterwards,
Proceed to F60, and process ΔT ₀ = ΔT ₁ .

Next, when the predetermined sampling time t _S is reached, the step
Go to F10 and read Ta, T _S again. Subsequently, the difference ΔT ₁ is calculated at F15. In this case, since the operation has started, proceed to F65. If it is determined in F65 that the compressor is in operation, the process proceeds to F45 and the frequency is calculated again by the above-mentioned formula. If Hz ≧ min, the operation is continued at the calculated frequency. When Hz <min, proceed to F80 and stop the compressor without outputting frequency output.

In order to operate the compressor again, in step F70, the compressor is started when the difference ΔT ₁ between Ta and T _P taken at each predetermined sampling time t _S becomes equal to or larger than the predetermined ΔT ₁₃ . At this time, the default Hz is set to Hz = min as shown in F75, and the above calculation is performed, and the compressor is operated at that frequency. Hereinafter, the above-described operation is repeated.

The above is shown in a mode diagram as shown in FIG. 3 at the start of operation and as shown in FIG. 4 other than the above. Third at the start of operation in figure, Ta and the difference [Delta] T ₁ of T _P is as no abrupt change at a frequency close to the min when less than ΔT _11, ΔT ₁₁ at greater than the base of the min frequency greater than ₁ As for, drive at a frequency as high as possible and operate so as to approach the set value as soon as possible. Once the operation is started, the operation is performed according to the mode diagram shown in FIG. That is, the frequency calculated by the formula of the machine is a
The range surrounded by -b-c-d-e-f can move freely depending on the condition. The calculated frequency is mi
When it becomes smaller than n, the inverter stops (below ef)
However, the inverter in which the difference ΔT ₁ between Ta and T _P is larger than the predetermined value ΔT ₁₃ is operated. Since the frequency at this time moves on the line a → c depending on the condition at that time, the higher the difference ΔT ₁ , the more
It can operate at high frequencies and can handle sudden changes. By doing so, not only the difference ΔT ₁ but also the temporal change of the load is satisfied, so that the operation can be performed at the frequency according to the load change at that time.

In other words, once operating, the load follows the fluctuations of the load, and at the time when the capacity changed by operating at a stable frequency within the specified sampling time affects the load, the necessary frequency is changed again. You can drive according to the condition. Therefore, extremely stable control can be performed. Changing the sampling time according to the size of the target load and the changing time enables even more optimal control.

〔The invention's effect〕

According to the present invention, since the capacity control matched to the load state can be stabilized, there is an effect that comfort can be ensured and highly reliable operation of the device can be achieved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 is a flow chart of operation, FIG. 3 is a mode diagram at the start of operation, and FIG. 4 is a mode diagram at the time of operation. 1 ... capacity setting means, 2 ... load detecting means, 3 ... computing device, 4 ... inverter, 5 ... motor, 6 ... compressor, 7 ... refrigeration cycle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kensaku Oguni 502 Jinritsucho, Tsuchiura-shi, Ibaraki Machinery Research Laboratory, Hiritsu Manufacturing Co., Ltd. (56) References JP-A-53-46150 (JP, A) JP-A-54 -89352 (JP, A)

Claims (4)

[Claims] 1. A refrigeration cycle formed by a compressor for compressing a refrigerant, a heat exchanger for each of a condenser and an evaporator, and an expander for a refrigerant, a motor for driving the compressor, and a power supply to the motor. In a method of controlling a heat source device by controlling an output voltage and an output frequency from the inverter to the motor of a heat source device having an inverter, a set value of the capacity setting means and a detected value of the load state detecting means are predetermined. Of each of the sampling times, calculate these deviations, and calculate the correction amount calculated by the calculation formula consisting of the sum of the term proportional to the deviation and the term mainly consisting of the temporal change of the deviation. In addition to the value, when this calculated value is larger than the specified value, this calculated value is output to the inverter to drive the motor, and when this calculated value is smaller than the specified value, it is not output to the inverter. When the motor is stopped and the deviation between the set value by the capacity setting means and the detected value by the load state detecting means becomes a certain value or more, the motor is started by the calculated value by the calculation formula. Method of controlling heat source device. 2. A refrigeration cycle formed by a compressor for compressing a refrigerant, heat exchangers for each of a condenser and an evaporator, and an expander for a refrigerant, a motor for driving the compressor, and a power supply to the motor. For controlling the output voltage and the output frequency from the inverter to the motor, the control means comprising a capacity setting means, a load state detecting means, a set value of the capacity setting means and the load. By inputting the detection value for each sampling time of the state detecting means, these deviations are calculated, and by an arithmetic expression consisting of a sum of a term proportional to the deviation and a term mainly consisting of the temporal change of the deviation. The calculated correction amount is added to the previous calculated value, and when this calculated value is larger than the specified value, this calculated value is output to the inverter to drive the motor, and when this calculated value is smaller than the specified value, it is output to the inverter. Let Then, when the deviation between the set value by the capacity setting means and the detected value by the load state detecting means exceeds a certain value, the calculating means starts the motor with the calculated value according to the arithmetic expression. A control device for a heat source device characterized by being configured. 3. A method for controlling a heat source device according to claim 1, wherein the set value by the capacity setting means is Ta, the detected value by the load state detecting means is T _S , ΔT ₁ = Ta−T _S , ΔT ₀ = ΔT ₁ , K ₁ , K _P at the time of the previous sampling are coefficients, t _S is the sampling time, the output frequency is Hz, and the correction amount is ΔHz. The correction amount is ΔHz = {K _P × A method for controlling a heat source device, characterized in that the heat source device is calculated by an arithmetic expression consisting of ΔT ₁ × t _S + K ₁ (ΔT ₁ −ΔT ₀ )} Hz. 4. The heat source device controller according to claim 2, wherein the set value by the capacity setting means is Ta, the detected value by the load state detecting means is T _S , ΔT ₁ = Ta−T _S , ΔT ₀ = ΔT ₁ , K ₁ , K _P at the time of the previous sampling are coefficients, t _S is the sampling time, the output frequency is Hz, and the correction amount is ΔHz. The correction amount is ΔHz = {K _P × A control device for a heat source device, characterized by being calculated by an arithmetic expression consisting of ΔT ₁ × t _S + K ₁ (ΔT ₁ −ΔT ₀ )} Hz.