JPS6149576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables the rotation speed of a compressor for compressing refrigerant to be higher than the rotation speed obtained at the commercial power frequency, and continuously varies the rotation speed, thereby steplessly increasing the cooling and heating capacity. It relates to controllable air conditioning equipment, and in particular displays the operating status, i.e., the rotation speed of the compressor or the cooling/heating capacity, so that the operating status of the equipment can be checked and the equipment can be used appropriately with the aim of saving energy. The goal is to further improve comfort, operability, and energy-saving effects obtained through stepless control of performance.

Conventionally, air conditioners using refrigerant compressors have been used to turn the refrigerant compressor on and off according to the load;
In the case of the pole number conversion method (for example, 2 poles ← → 4 poles switching), there were some that controlled the rotation speed by high/low/off control. The cooling and heating capacity of these air conditioners is determined by whether the compressor is operating or not, and whether it is in two-pole or four-pole operation, and the control of the air conditioned room is based on these operations and indoor This was done by varying the strength of the circulation fan.

For this reason, the comfort level is not sufficient, and even if an attempt is made to aim for energy-saving operation, there is no standard or guideline, and there is no practically effective means.

In order to eliminate the above-mentioned conventional drawbacks, the present invention continuously changes the rotation speed of the compressor.
Significantly improves comfort, improves efficiency under normal usage conditions, and displays compressor rotational speed or cooling/heating capacity to experience the correlation between indoor air conditions and equipment operating conditions (capacity). It is an object of the present invention to provide an air conditioner that enables proper operation methods and energy-saving operation by making it easy to recognize the situation.

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an air conditioner that heats and absorbs heat using a heat pump type refrigerant cycle, and the figure particularly shows a separate type air conditioner.

1 is an outdoor unit, 2 is an indoor unit,
The outdoor unit includes a compressor 3 (here, a small, lightweight, and efficient rotary compressor), a motor 4 for driving the compressor, a four-way valve 5 that switches the refrigerant cycle for cooling, heating, and defrosting, and an outdoor unit. heat exchanger 6,
It has an outdoor fan 7. The indoor unit 2 includes a pressure reducing device 8, an indoor heat exchanger 9, and an indoor fan 10.

11 is a commercial power supply, and here a three-phase 200V power supply is used. Reference numeral 12 denotes a power supply circuit, which supplies power to the motor 4 and can continuously control its rotation speed, and also controls the maximum rotation speed of the motor 4 to the rotation speed obtained at the commercial power frequency (maximum 3600 rpm, at 60 Hz). )
It is possible to operate up to a higher value than . 13
is a speed command circuit, which sends the motor 4 to the power supply circuit 12 according to the signals from the room temperature detection element 14 and the room temperature setting device 15.
It emits a speed setting voltage V _s that determines the rotation speed of the motor. 1
Reference numeral 6 denotes a heating/cooling changeover switch for switching between cooling and heating, which switches the four-way valve 5 etc. according to the operation signal H/C, and also performs the cooling/heating switching operation of the signal in the speed command circuit 13.

17 is a display element, the motor 4, that is, the compressor 3;
The speed setting voltage _Vs , etc. corresponding to the rotation speed N of the compressor is input from the speed command circuit 13, and the status of the room temperature, set room temperature, and compressor rotation speed (or cooling/heating capacity) during cooling/heating operation is displayed. It is.

With the above configuration, first, the speed command circuit 13
generates a speed setting voltage V _s to the power supply circuit 12 according to the difference between the room temperature and the set room temperature based on signals from the room temperature detection element 14 and the room temperature setter 15 . The power supply circuit 12 thereby supplies power to the motor 4 and
The rotational speed of the motor is controlled so that it has a value corresponding to the speed setting voltage _Vs. Since the compressor 3 is directly connected to the motor 4, it rotates at the same rotation speed N and compresses the refrigerant, thereby heating the room temperature and absorbing heat in the indoor heat exchanger 9, thereby performing cooling or heating operation. It can be done. When the rotation speed N of the compressor 3 is changed,
Since the amount of refrigerant to be compressed changes, the cooling/heating capacity also changes, so the room temperature is ultimately maintained at the set room temperature.

Here, the specific configuration of the speed command circuit 13 and display device 17 described above will be explained with reference to FIG.

In FIG. 2, the speed command circuit 13 includes an amplifier 18 receiving the signal from the room temperature detection element 14, an amplifier 19 receiving the signal from the room temperature setting device 15, and output signals V _r and V _d of the two amplifiers 18 and 19. A differential amplifier 20 that outputs the difference between the input signals, a switching circuit 21 that converts the output signal of the differential amplifier 20 into a difference signal Δθ suitable for cooling and heating using the signal from the cooling/heating switch 16, and the difference signal Δθ. The converter circuit 22 is configured to output a speed setting voltage V _s for giving the rotational speed N that the compressor 3 should take.

The display device 17 converts the signal V _r corresponding to the room temperature output from the amplifier 18, the signal V _d corresponding to the set room temperature output from the amplifier 19, and the speed setting voltage V _s into digital quantities. A/D converter 2
3, 24, and 25, and also includes display element groups 28, 29, and 30 that are lit by the outputs of these A/D converters 23, 24, and 25. The three display element groups 28, 29, and 30 are composed of one display tube 26 using a fluorescent tube, and each display element group 28, 29, and 30 is composed of a plurality of display elements 27 arranged in a row. It is being formed. In this way, the display device 17 uses the signal from the speed command circuit 13 to clearly display the room temperature during cooling/heating operation, the set room temperature, and the rotation speed of the compressor 3 (or the cooling/heating capacity) on one display tube 26. It is done like this.

Next, the conversion circuit 22 in the speed command circuit 13
The operation will be explained in more detail. 3 is an explanatory diagram showing its input/output characteristics, and FIG. 4 is a characteristic diagram of the embodiment of FIG. 1 including this speed command circuit 13.

In Fig. 3, the speed setting voltage V _s with respect to the difference signal Δθ (i.e., the difference between the room temperature and the set room temperature) is normally proportional to Δθ, and has hysteresis at V _p or V _L in the region where Δθ is small. On/off characteristics, in the region where Δθ is large, V _H (during heating) or V _C (during cooling)
limited by.

These reasons are as follows: a) If the compressor 3 becomes too slow, the oil lubrication of the compression part will be insufficient and cause seizure, so in order to avoid extremely low speed operation,
b) In the high-speed range, the maximum rotation speed that the compressor 3 can take is limited from the viewpoint of lifespan, etc., and the maximum capacity when cooling is compared to the capacity required during heating, and when the same air conditioned room is targeted. This is because the rated rotational speed of each compressor 3 is determined corresponding to heating and cooling, so that the indoor heat exchanger 9 can be kept small and prevent condensation from forming due to excessive cooling.

To explain using Fig. 4, the cooling capacity Q _C and heating capacity Q _H of the compressor 3 have the characteristics as shown in the figure with respect to the rotational speed N, and the efficiency η (capacity Q and electrical input W ) are η _C and η _H , respectively.

The speed setting voltage V _s and the rotation speed N are almost proportional, and when V _s = V _L , V _C , V _H , N = N _L , N
_C , N _H , and during cooling operation, N=O and N _L ~
_During heating operation, variable speed operation is performed between N = O and between N _L and N _H , and the room temperature is controlled at a constant level while maintaining equipment stability and energy-saving operation, achieving extremely high comfort. It is something that will be done.

Next, when such operating characteristics are obtained, as a method of displaying the rotation speed or capacity of the compressor 3 on the display device 17, as shown by symbol A in FIG. 3, each display element of the display element group 30 is turned on. If the state is made proportional to _Vs , then a linear display corresponding to the rotation speed N of the compressor 3 can be obtained. Furthermore, if it is done as shown in signal B, the display method will be such that the continuously variable speed range of the compressor 3 is expanded to almost 100%. In either case, a linear relationship is obtained with respect to the rotation speed N of the compressor 3. Also A/D converter 25
It is also possible to modify the equation so that the respective cooling and heating capacities shown in FIG. 4 are displayed linearly.

In other words, there are several possible display methods that correspond to the rotational speed N of the compressor 3, or the cooling and heating capacity Q _C or Q _H , and you can select one according to the purpose of use, but in general, the display method is shown as signal A in Figure 3. This would be the easiest method.

Finally, a specific configuration of the power supply circuit 12 shown in FIG. 1 is shown in FIG. In FIG. 5, 20 is a rectifier circuit that converts the commercial power supply 11 into DC, and 21 is a chopper circuit that converts the DC voltage V _dc1 from the rectifier circuit 20 into a DC voltage V _dc2 corresponding to the speed setting voltage V _s. , and 22 uses V _dc2 generated by the chopper circuit 21 as a power source, and the three-phase AC voltage V _{M output from the inverter circuit 22 which generates the three-phase AC voltage V M with} a frequency that is engaged with that value is an AC induction voltage. The voltage is applied to the motor 4, which is an electric motor. 23 is a control circuit that controls the chopper circuit 21 and the inverter circuit 22. This power supply circuit 12
This is generally called a variable voltage, variable frequency inverter, and the one shown in this embodiment is particularly designed to drive the compressor 3 stably.

The present invention has been described above based on the embodiments, but in addition to the embodiments, 1) the display device 17 can be realized not only by using a fluorescent display tube but also by a light emitting diode, a plasma display, etc.; It is possible to display on the same display element group by combining dimming and continuous lighting, and even if these are omitted and only the rotation speed N of the compressor 3 or the cooling/heating capacity is displayed, the operating status of the equipment, It is possible to accurately determine the state of room temperature, etc.

2) The same effect can be obtained even when this device is capable of both cooling and heating, and even if it is only for standalone operation. In addition, in the example, the compressor 3 during cooling
However, by increasing the maximum rotation speed during cooling to the same value as that during heating for a predetermined period of time at the start of cooling operation, the rise characteristics (in fact, the fall )
It is also possible to improve this significantly.

3) In addition to using a variable voltage variable frequency inverter as the power supply circuit 12, it is also possible to use a so-called transistor motor if configured to be suitable for driving the compressor 3. That is, a DC motor is used as the motor 4, a corresponding inverter is used as the power supply circuit 12, and the motor 4 is driven at variable speed. Although the speed setting voltage V _s is used for this purpose, it is also possible to use an appropriate signal within the power supply circuit 12.

As described above, the air conditioner according to the present invention can steplessly change the rotational speed of the compressor and continuously change the cooling and heating capacity, so it can provide unprecedented comfort and control its operating status. Since the display device allows accurate information to be understood, it not only enables stable operation of the equipment but also promotes appropriate operating methods and highly efficient energy-saving operation, which has great effects. It is.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a specific configuration diagram of the speed command circuit and display device in Figure 1, Figure 3 is an explanatory diagram of the operation of Figure 1, and Figure 4 is a diagram illustrating the operation of Figure 1.
This figure is a characteristic diagram of FIG. 1, and FIG. 5 is a configuration diagram of the power supply circuit in FIG. 1. DESCRIPTION OF SYMBOLS 1... Outdoor unit, 2... Indoor unit, 3... Compressor, 4... Motor, 5... Four-way valve, 6... Outdoor heat exchanger, 7... Indoor heat exchanger, 12... Power supply circuit 13... Speed command circuit, 17... Display device, 26...Display tube.

Claims (1)

[Claims] 1. A refrigerant circuit mainly consisting of a compressor for compressing refrigerant, a power supply circuit that supplies power to the drive motor of the compressor and controls the rotation speed of the compressor by continuously variable speed driving, and a a speed command circuit that issues an output signal to the power supply circuit corresponding to the indoor load state of the compressor, and three or more display elements arranged in a line, and the speed An air conditioner comprising: a display device that lights up predetermined display elements in order from one end, and lights up all of the display elements when the rotational speed or heating and cooling capacity of the compressor is in the maximum range.