JP2550094B2 - Air conditioner operation control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in an operation control method for an air conditioner, particularly when the temperature difference between a set temperature and room temperature has a predetermined value or more at the start of operation. is there.

[Conventional technology]

It is good if the capacity of the air conditioner is large and there is a large temperature difference between the set temperature and room temperature, but it can be controlled easily, but operation of a conventional air conditioner when a capacity larger than the unit's rated capacity is required is required. The control method will be described with reference to FIG. 3 in the case of heating. FIG. 3 is an explanatory diagram in which the horizontal axis represents time and the vertical axis represents temperature and compressor rotation speed. In the figure, t ₀ is the set temperature to be held, t ₁
Is the normal OFF temperature, t ₂ is the maximum rotation speed release temperature of the compressor, and this maximum rotation speed release temperature t ₂ is the predetermined temperature difference between the set temperature t ₀ and room temperature when the air conditioner starts operating. In the above cases, the temperature is set to lower the rotation speed after operating the compressor at the maximum rotation speed to raise the room temperature to a comfortable temperature in a short time. It should be noted that the maximum rotation speed release temperature t ₂ takes a long time until the wall, floor, etc. warm up even if the room temperature rises. Therefore, the temperature is set higher than the normal OFF temperature t ₁ to prevent chills. I'm out. t ₃ is the compressor operation OFF temperature. Even if the rotation speed is controlled to be low by the maximum rotation speed release temperature t ₂ , if the load is small, the room temperature does not decrease and rises. Is set to do. t ₄ is a normal ON temperature, t _R is room temperature, T is a compressor large capacity operation time, T ₁ is a fixed rotation time, and P is a compressor rotation speed curve. Then, the high-capacity operation is performed for the high-capacity operation time T, or is released after the maximum rotation speed release temperature t ₂ is reached, and the compressor rotation speed is gradually reduced to MIN. After operating for a fixed time T ₁ , control is shifted to the temperature difference between the set temperature t ₀ and the room temperature t _R. However, the control in FIG.
Since the room temperature t _R shown by the solid line has just reached the compressor operation OFF temperature t ₃ at the end of the rotation speed fixed time t ₁ at the MIN rotation speed, the rotation speed of the compressor indicated by the compressor rotation speed curve P is 0.
I have to.

The operation control shown in FIG. 3 will be described in detail below. Even if the control proceeds to the control in which the compressor large capacity operation time T ends and the compressor rotation speed gradually decreases, the room temperature t _R is as shown by the solid line. Although it may rise, when the load is large, the rotation speed starts to fall and the room temperature t _R falls as shown by the dotted line. This lowering continues until the compressor is rotationally driven at the intersection A with the normal OFF temperature t ₄ after the compressor has stopped after the fixed rotation speed T ₁ has passed, and at this intersection A the compressor is driven. The room temperature t _R rises as shown by the dotted line with a slight delay after being driven. on the other hand,
If the load is small, the room temperature t _R If the upper load is small, such as room temperature t _R the rotation speed is reduced in a large capacity driving the compressor past the time T is the solid line increases as the solid line The operation is stopped at the point E of the compressor operation OFF temperature t ₃ during high-capacity operation, and then decreases after reaching the maximum point C and the normal ON temperature t ₄
The compressor is rotationally driven at the intersection point B with the room temperature t on the dotted line.
Similar to the case of _R , control is performed by the temperature difference between the set temperature t ₀ and the room temperature t _R.

[Problems to be solved by the invention]

In the above-mentioned conventional technique, when the operation is stopped due to a rise in room temperature after reaching the maximum rotation speed release temperature t ₂ at the start of compressor operation, the maximum point C and the minimum point D of the curve of the room temperature t _R are Since the temperature difference is large and the operation is frequently stopped, no consideration is given to reducing the temperature difference at room temperature and reducing the frequency of operation stop, and it is difficult to follow the set temperature and the comfort level is low. There was a problem to say.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an operation control method for an air conditioner that has good followability to a set temperature and can improve comfort.

[Means for solving problems]

In the air conditioner that performs stepless speed change control of the compressor for refrigerant compression from the minimum rotation speed to the maximum rotation speed according to the air conditioning load, the room temperature t _R at the start of the heating operation is higher than the set temperature t _O. Is also low
When the temperature difference between the set temperature t _O and the room temperature t _R is less than a predetermined value, the compressor rotation speed determined by the temperature difference between the room temperature and the set temperature is controlled, and then the room temperature t _R is When the temperature rises and reaches the normal OFF temperature t ₁ , the compressor is stopped, and when it decreases to the normal ON temperature t ₄ lower than the normal OFF temperature t ₁ , the compressor is controlled to operate. room temperature t _R is lower than the set temperature t _O, and when the temperature difference between the set temperature t _O and the room temperature t _R is equal to or higher than the predetermined value, controls the compressor to the maximum rotational speed, then the room temperature When t _R exceeds the set temperature t _O , the maximum rotation speed release temperature t ₂ set to the normal OFF temperature t ₁ or more
When the maximum rotation speed is reached, the maximum rotation speed is released and the compressor is controlled to operate for a fixed time T ₁ at a fixed rotation speed lower than the maximum rotation speed and higher than the minimum rotation speed, and then the room temperature t _R and the above The control shifts to control of the compressor rotation speed during normal operation, which is determined by the temperature difference from the set temperature t _O, and after this shift, the room temperature t _R
Is higher than the maximum speed release temperature t ₂ above Compressor operation OFF
And performing control to stop the rotation speed of the compressor when temperature rises to t _3, the maximum rotational speed release temperature t ₂ of the compressor, OFF temperature t ₁ the same as or close to the temperature of the compressor in normal Is set to, and the operation control method of the air conditioner in which the temperature difference between the compressor operation OFF temperature t ₃ and the maximum rotation speed release temperature t ₂ is widened is achieved.

[Action]

As described in the description of the embodiments below, in FIG. 2, the input that is the control symmetry of the compressor rotation speed is:
The room temperature data a and the set temperature b are calculated. The difference between these two data is calculated by the data editing circuit c, transferred to the control circuit d, and the control circuit d outputs the rotation speed output value f to the compressor motor e. It At the start of operation, whether or not to perform the high-capacity operation in which the compressor speed is maximized is determined by the room temperature data a and the set temperature b.
And the data editing circuit c, and in the case of operation, the subsequent release is determined by the data editing circuit c according to the time and the previous two inputs. After that, if it is within the large-capacity operation time T in FIG. 1, the data editing circuit c is provided with a function of continuously sending the illustrated rotation speed to the control circuit d for a fixed time during the fixed rotation time T ₁ , which causes an operation stop or a temperature difference. Occurrence can be reduced.

〔Example〕

An operation control method for an air conditioner according to the present invention will be described below with reference to FIGS. 1 and 2 using an embodiment. FIG. 1 is an explanatory diagram, and FIG. 2 is a control block diagram of an air conditioner for carrying out the method of FIG. In the figure, a is room temperature data, b is a set temperature, c is a data editing circuit, d is a control circuit, e is a compressor motor, and f is a rotation speed output value. The difference between the room temperature data a and the set temperature b is calculated by the data editing circuit c, the compressor motor e is driven through the control circuit d, and high capacity operation is started.
After that, when the room temperature t _R reaches the maximum rotation speed release temperature t ₂ (point F) during the high capacity operation time T, the compressor rotation speed is reduced M
Operate for a fixed rotational speed time T ₁ at an arbitrary rotational speed higher than IM. (However, maximum rotation speed release temperature t ₂ (point F)
If it does not reach the set temperature, the set temperature t ₀
And the normal operation control is performed by the difference between the room temperature t _R and the room temperature t _R ), and the room temperature t _R is lowered from the point F to the normal ON temperature t ₄ (point A) as indicated by the alternate long and short dash line during the fixed rotation speed time T ₁ . In the case, at the point A, the normal operation control is performed depending on the difference between the set temperature t ₀ and the room temperature t _R. However, the room temperature t _R is the point F as shown by the one-dot chain line.
If the room temperature t _R rises to the point F as shown by the solid line within the large capacity operation time T without decreasing from above, and further reaches the compressor operation OFF temperature t ₃ (point E) at the time of large capacity operation as shown by the chain line. The operation stops and the compressor speed becomes zero. In addition, G is a rotation speed curve at the time of normal operation. However, compressor operation during high capacity operation
The OFF temperature t ₃ is higher than the temperature normally considered in the case of general design in this type of equipment compared to the case of FIG. The temperature difference between t ₃ and the maximum rotation speed release temperature t ₂ is larger than that in the conventional case shown in FIG. In order to increase this temperature difference, in addition to setting the compressor operation OFF temperature t ₃ higher than in the conventional example as described above,
As shown in FIG. 1, the maximum rotation speed release temperature t ₂ is normally 0
The temperature may be set to be the same as or close to the FF temperature t ₁ , and in the embodiment of FIG. 1, the compressor operation OFF temperature t ₃ is set higher than that of the conventional example and the maximum rotation speed release temperature t _{2 is set} to normal. A large temperature difference is easily obtained by setting the same as the OFF temperature t ₁ . After passing the operating point E of the compressor operation OFF temperature t ₃ , the room temperature t _R decreases as shown by the solid line through the point C and reaches the normal ON temperature t ₄ at the point B, and then the normal operation starts.
The compressor operation OFF temperature t ₃ is higher than the conventional one, and the maximum rotation speed release temperature t ₂ is set to be the same as the normal OFF temperature t ₁ to increase the temperature difference. Although the compressor operation OFF temperature t ₃ of No. ₃ was stopped and the operation was stopped, the intermittent operation can be prevented without causing this operation stop, that is, the frequency of the operation stop can be reduced. Further, by providing the compressor rotation speed fixed time T ₁ having a rotation speed larger than MIN within the large capacity operation time T, the temperature difference between the lowest point (not shown) of the room temperature t _R and the point C is small. Becomes room temperature t _R
It is possible to prevent discomfort caused by the descent of.

Thus, in the operation control method of the air conditioner of the present embodiment, the temperature difference between the compressor operation OFF temperature and the maximum rotation speed release temperature is widened, and the large capacity for maximizing the compressor rotation speed at the start of operation. When the room temperature reaches the specified value for the set temperature after the operation, the large capacity operation is released, and the compressor speed is determined by the temperature of the room temperature and the set temperature after the fixed speed time of the minimum speed or more has passed. Since the rotation speed control is performed, the temperature difference between the room temperatures is reduced, the frequency of operation stop is reduced, the followability to the set temperature is good, and the discomfort caused by the decrease in the room temperature is eliminated and the comfort can be improved.

〔The invention's effect〕

According to the present invention, the maximum rotation speed release temperature t of the compressor is
₂ is set to a temperature equal to or close to the OFF temperature t ₁ of the compressor at the normal time, and the temperature difference between the compressor operation OFF temperature t ₃ and the maximum rotation speed release temperature t ₂ is widened, so that the room temperature is compressed. The possibility that the machine operation OFF temperature t ₃ is reached and the operation is stopped is reduced. In addition, the maximum rotation speed is released when the room temperature reaches the maximum rotation speed release temperature t ₂ , and the compressor rotation speed is increased. Is controlled to operate for a fixed time at a rotational speed higher than the minimum rotational speed, so that the room temperature is the compressor operation OFF temperature t ₃
To further reduce the possibility that the operation will be stopped, and then control or stop the compressor at the normal OFF temperature t ₁ and the normal ON temperature t _{4 and} control the temperature between the room temperature and the set temperature. By shifting to the control of the compressor speed determined by the difference, it is possible to prevent a large decrease in room temperature due to the operation being stopped at the start of operation, and it is possible to reduce the temperature difference between the lowest point and the highest point of room temperature and to stop the operation. The frequency of can be reduced, the followability to the set temperature is good, the discomfort caused by the decrease in room temperature can be eliminated, and the comfort can be improved.

[Brief description of drawings]

1 is an explanatory view of an embodiment of an operation control method for an air conditioner of the present invention, FIG. 2 is a control block diagram of an air conditioner for implementing the method of FIG. 1, and FIG. 3 is a conventional air conditioner. FIG. 3 is an explanatory diagram of the operation control method of FIG. t ₀ ... set temperature, t ₂ ... maximum rotation speed release temperature, t ₃ ...
… Compressor operation OFF temperature during high capacity operation, t _R …… room temperature, T ₁
...... Rotation speed fixed time, t ₄ ...... Normal ON temperature, T ...... High capacity operation time, t ₁ ...... Normal OFF temperature.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomotsu Kaneko 800 Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Tomita Co., Ltd. Tochigi Plant, Hitachi Ltd. (56) Reference JP 60-71842 (JP, A) 57-10017 (JP, U)

Claims (1)

(57) [Claims] 1. An air conditioner in which a compressor for compressing a refrigerant is subjected to stepless speed change control from a minimum rotation speed to a maximum rotation speed according to an air conditioning load, and a room temperature t _R at the start of heating operation is a set temperature t _O. When the temperature difference between the set temperature t _O and the room temperature t _R is less than a predetermined value, the compressor rotation speed determined by the temperature difference between the room temperature and the set temperature is controlled, and then When the room temperature t _R rises and reaches the normal OFF temperature t ₁ , the compressor is stopped,
Then, the normal ON temperature t ₄ lower than the normal OFF temperature t ₁
Until to control to operate the compressor decreases, room temperature t _R at the start heating operation is lower than the set temperature t _O, and when the said set temperature t _O the temperature difference between the room temperature t _R is equal to or higher than the predetermined value , The compressor is controlled to the maximum rotation speed, and then the room temperature t _R exceeds the set temperature t _O ,
When the maximum rotation speed release temperature t ₂ set to the OFF temperature t ₁ or higher is reached, the maximum rotation speed is released and the compressor is fixed at a fixed rotation speed lower than the maximum rotation speed and higher than the minimum rotation speed. Control is performed to operate for a time T ₁ , and then the control proceeds to control of the compressor rotation speed during normal operation that is determined by the temperature difference between the room temperature t _R and the set temperature t _O, and after this transition, the room temperature t _R reaches the maximum rotation speed. and performing control to stop the rotation speed of the compressor when increased high to compressor operation OFF temperature t ₃ than the number released temperature t _2, the maximum rotational speed release temperature t ₂ of the compressor, during the normal An air conditioner operation characterized in that the temperature is set to be equal to or close to the OFF temperature t _{1 of the} compressor to widen the temperature difference between the compressor operation OFF temperature t ₃ and the maximum rotation speed release temperature t _2. Control method.