JPH01318845A - Air-conditioning apparatus - Google Patents

Abstract

PURPOSE:To keep fans from running at unnecessary rates of revolution in order to minimize their noise and prevent waste of power consumption by regulating the revolution of the fans independent of the operation of the compressor so as to balance the capacity of the compressor for cooling or heating with the heat exchange capacities of the interior and the exterior heat exchangers. CONSTITUTION:The speeds at which motors drive fans 6, 8 for interior and exterior heat exchangers 5, 7 respectively can be changed by changing the power supplied thereto and, accordingly, the revolutions of the fans can be adjusted to the loads on the heat exchangers; from a source of AC 100V the power is obtained through a power converter 27 which uses a variable resistor 21 to change the power output in adjusting the revolutions of the fans. On the other hand, the output frequency of an inverter 12, that is, the number of revolution of a compressor 3, can be changed by means of a variable resistor 20; therefore, the variable resistors 20 and 21 are interlocked to form an interlocking variable resistor 22, by virtue of which the number of revolution of the compressor and those of the fans can be changed at a stroke simultaneously. Since a semi-fixed resistor 23 can be adjusted to represent the changes of the gradients between the graduation of the variable resistor 21 and the heat exchange capacities of the interior and exterior heat exchangers 5, 7, the gradient between the numbers of revolution of the compressor 3 and the cooling and heating capacities and those between the numbers of revolution of the fans 6, 8 and the respective heat exchange capacities can be integrated.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a technology for controlling a heat exchanger fan in an air conditioner, and particularly to a technology for controlling a heat exchanger fan in a vehicle air conditioner. It is.

(Prior Art) Air conditioners that use fluorocarbon gas or the like as a refrigerant to perform cooling and heat pump heating are well known, and are used in various configurations depending on the purpose. Of these, the system with the most basic configuration that does not use an inverter is the second one.
As shown in the figure. In FIG. 2, AC power input from input terminals 1 and 1' is applied to a compressor 3 via a switch 2. In FIG.

The compressor 3 compresses gas, and the gas passes through a four-way valve 4 to an internal heat exchanger 5, which is an internal device installed in a place where heating and cooling is performed, and then to an external heat exchanger 5, which is installed in a place where heat is radiated or absorbed. It passes through the exchanger 7 and returns to the compressor 3 via the four-way valve 4 again. The four-way valve switches the gas path for heating and cooling, and the gas circulation path for cooling is shown by a solid line arrow, and the gas circulation path for heating is shown by a broken line arrow. The heat exchangers 5 and 7 are provided with fans 6 and 8, respectively, to provide ventilation. In conventional air conditioners, the rating of the fan 6 or 8 is set according to the maximum amount of heat release or absorption, and the fan 6 or 8 is always operated at this rated rotation speed. Temperature adjustment is performed by manually turning the switch 2 on and off in the simplest configuration, such as one installed in a vehicle. Switch 2 for broadcast relay vehicles, etc.
Many models use a temperature controller 9 to drive a magnetic relay 10 to automatically turn on and off.

The above-mentioned temperature controller 9 is equipped with an internal temperature detection means and a temperature specifying means, and in the case of cooling, the switch 2 is closed when the detected temperature exceeds the specified temperature, and the switch 2 is opened when the detected temperature is lower than the specified temperature, and vice versa in the case of heating. All you have to do is make it . As a special example, a bypass valve 11 is installed in parallel with the compressor 3, and by adjusting this valve, the amount of gas passing through the heat exchanger 5 or 7 is adjusted to adjust the temperature, and the power switch 20 does not have to be turned on or off. There is something like this. All broadcast relay vehicles used one of these methods without exception.

On the other hand, when it is necessary to increase the cooling and heating capacity of the compressor 3 (the number of revolutions of the compressor and the amount of gas delivered are proportional, but the amount of heat exchanged when ideal heat exchange is performed by this delivered gas) Inverter air conditioners are now being used, which increase the rotation speed of the compressor and lower the rotation speed when the compressor is small, and these inverter air conditioners have become the mainstream for home air conditioners. Figure 3 shows a typical system configuration of an inverter air conditioner. The inverter 12 efficiently converts AC input into variable frequency AC, and power to the compressor 3 is supplied via the inverter. The output frequency of the inverter 12 is controlled by an internal computer to match a specified internal temperature (room temperature). This temperature control includes detection by a temperature detector 13 of the internal heat exchanger @5, an internal temperature detector 14, a temperature detector 15 of the external heat exchanger 7, an external temperature detector 16, and a temperature detector 17 of the compressor 3. temperature and the internal temperature mentioned above are referenced and act to lower or raise the output frequency. Power for the internal fan 6 is supplied from the inverter 12 via the air volume controller 18 similarly to the compressor 3, and power for the external fan 8 is supplied directly from the original power supply without passing through the impark 3. Therefore, the rotational speed of the internal fan 6 is proportional to the rotational speed of the compressor 3, and can also be changed depending on the strength of the airflow specified by the airflow controller 18. On the other hand, the rotation speed of the external fan 8 is constant.

When installing heat exchangers and fans, if there is sufficient space, they should be large in size to reduce ventilation resistance, and should be of the so-called air volume type that sends a large amount of air at a low rotation speed. in this case,
The wind noise of the fan can be reduced. When mounting space is limited, it is necessary to have a small size, which increases ventilation resistance, so a so-called wind pressure type is used, which eliminates this large resistance and sends a small amount of air at a high rotational speed.

In this case, the wind noise from the fan becomes louder.

In the case of industrial equipment such as household inverter air conditioners, after careful consideration including experiments, the external equipment uses a type with ample airflow. It rotates at a constant speed that corresponds to maximum output.

On the other hand, in the case of on-vehicle use, space is limited and it is generally difficult to increase the size of the heat exchanger and fan, so a wind pressure type structure is adopted.

(Problem to be solved by the invention) As shown in Figure 2, an air conditioner that does not use an inverter,
Since the fan of the heat exchanger is always operated at the rotation speed at the maximum load, there is a problem that not only is power was wasted when the load is light, but also the wind noise of the fan becomes high.

This problem is exacerbated by the fact that vehicle air conditioners generally have a wind-pressure type configuration due to limited installation space. In particular, in the case of broadcast relay vehicles, space is given priority to broadcasting equipment, and only a small amount of space is often devoted to power supplies and especially air conditioners, so they are often of the extreme wind pressure type. As a result, wind noise becomes abnormally high, causing problems such as wind noise entering microphones used for broadcast interviews near broadcast vehicles, and being considered as a pollution problem in residential areas and other places where silence is required. This results in restrictions. Furthermore, when the air conditioner shown in FIG. 2 is used in a broadcasting relay vehicle, the power is turned on and off by an electromagnetic relay 10 for temperature control, which causes problems with voltage fluctuations and electrical noise. That is,
The power consumption of air conditioners is approximately 1 of the power consumption of broadcasting equipment.
Since the number of relays reaches 0 times, fluctuations in the power supply voltage and generation of electrical noise are unavoidable due to the on/off of the relays, and electrical disturbances occur due to the on/off of the relays, which poses a problem of adversely affecting the transmitted image.

The above-mentioned noise generation is not a problem when temperature control is performed by the bypass valve 11 of the compressor 3 shown in Fig. 2 because the power supply is not turned on and off, but the external fan 8 always operates at maximum capacity. , the problem of wind noise is not solved. Furthermore, even if the inverter 12 is used as shown in Fig. 3 and power is supplied to the compressor 3 from the inverter, the power to the external fan 8 is directly supplied from AC 100V, so the problem of wind noise cannot be solved. The same is true.

Due to the above problems, in the case of broadcasting relay vehicles,
During broadcasts, the air conditioner had to be turned off, forcing operators to work in poor conditions.

In order to solve this problem, it is conceivable to supply power to the fans 6 and 8 of the heat exchangers 5 and 7 together with the compressor 3 in an in-vehicle air conditioner from an inverter. In , the heat exchange capacity (the amount of heat exchanged when there is a certain difference between the temperature of the heat exchanger and the inside or outside) with respect to the rotation speed of the fan,
It changes depending on the temperature difference. ) is larger than the slope of the heating and cooling capacity with respect to the rotational speed of the compressor, so the problem of mismatch between the heating and cooling capacity and the heat exchange capacity remains. That is, if the maximum capacity of the fan is set to the upper limit of the practical range, there will be a lack of capacity at the lower limit, and if it is set to the lower limit, as the rotation speed increases, a surplus of capacity will occur, resulting in wasted power consumption.

To solve the above problem, install an inverter separate from the inverter for the compressor, drive the fan with this inverter, and adjust the frequency of the inverter to roughly match the fan's capacity and the compressor's heating and cooling capacity. Although it is obvious that this is a good thing, doing it this way increases costs and is not a desirable solution.

Furthermore, in Japan, most broadcasting relay vehicles are manufactured to order with different specifications for each vehicle, so it is not possible to allocate enough time to design the air conditioner, which is an obstacle to designing a desirable air conditioner. ing.

(Means for Solving the Problems) The air conditioner of the present invention supplies power to the compressor from an inverter, and supplies power to the fans for the internal heat exchanger and the external heat exchanger from an AC power source via a power converter. It was designed to do so.

In a preferred embodiment of the present invention, a variable resistor is provided in the inverter to adjust the rotation speed of the compressor, and a variable resistor is provided to adjust the output voltage of the power converter, and these variable resistors are used as interlocking variable resistors. , so as to regulate the internal temperature.

(Function) In the air conditioner of the present invention described above, by introducing an inverter as a power source for the compressor, the rotation speed can be adapted to the load, and the power source for the fan can be converted from the input power source. By supplying heat through a heat exchanger, the heat exchange capacity of the heat exchanger can be set to match the heating and cooling capacity of the compressor.

Furthermore, when using an interlocking variable resistor, by simply adjusting the temperature scale of the interlocking variable resistor, it is possible to roughly match the specified temperature while satisfying the above conditions.

(Example) Next, the invention will be explained in detail using the drawings.

FIG. 1 is a drawing showing one embodiment of an air conditioner according to the present invention, and the same elements as those shown in FIGS. 2 and 3 are denoted by the same reference numerals. The drive motors for the fan 6 of the internal heat exchanger 5 and the fan 8 of the external heat exchanger 7 usually use single-phase commutator motors, and the speed can be changed by changing the supplied power. In the present invention, since the rotation speed of the fan is matched to the load of the heat exchanger, the AC applied between the input terminals 1 and 1'
Power is supplied from looV via a power converter 27. This power converter 27 is configured by a known circuit using, for example, Cyrisk, and can adjust the rotational speed of the fan by changing the output power using the variable resistor 21. For example, DIAC (product name)
as the trigger element, SCR or TRIAC (product name)
A method of driving can be adopted. Such circuits are commercially available (for example, the speed controller manufactured by Nippon Blower Co., Ltd.) and can be used at a much lower cost than inverters.

On the other hand, the output frequency of the inverter 12, that is, the rotation speed of the compressor 3, can be configured to be changed by the variable resistor 20, so the variable resistors 20 and 21 are linked to form the linked variable resistor 22, The rotation speed of the compressor and the rotation speed of the fan can be changed simultaneously by one action.

On the other hand, the sensitivity of the variable resistor 21, that is, the gradient of change in the scale of the variable resistor versus the heat exchange capacity of the internal and external heat exchangers, can be changed by adjusting the semi-fixed resistor 23, so that the The gradient of change in rotational speed versus heating and cooling capacity and the gradient of variation in rotational speed of the fan versus heat exchange capacity can be made approximately the same.

The amount of heat actually exchanged by the heat exchanger increases when the temperature difference between the fins of the heat exchanger and the internal or external air is large, and decreases when it is small, so the fan rotation speed is changed depending on the temperature difference. I need to do it. In this embodiment, the resistor 24 is changed to the switch 25 depending on the external temperature.
The combined resistance value of the resistors 21, 23 and 24 is changed by switching to several stages, and as a result, the number of revolutions of the fan is changed to adjust the amount of heat exchanged by the external heat exchanger. In this way, by matching the set temperature to the temperature scale provided on the interlocking variable resistor 22, the internal temperature can be adjusted in a state where the rotation speed of the compressor versus cooling/heating capacity and the rotation speed of the fan versus heat exchange capacity roughly match. It is possible to adjust the temperature to approximately the set temperature. Although the accuracy of the temperature scale provided on the interlocking variable resistor 22 changes by switching the resistor 24, this temperature scale shows a rough guide, so there is no problem in practical use. In this state, the computer inside the bark 12 does not directly control the temperature, but only protects the compressor 3, internal heat exchanger 5, or external heat exchanger 7 from overheating.

In the embodiment described above, the interlocking variable resistor 22 is manually set to a specified temperature, but the rotation speed of the compressor 3 and the output voltage of the power converter 27 are controlled by a computer. The internal temperature can also be adjusted to the set temperature when the machine's rotational speed versus cooling/heating capacity and the fan's rotational speed versus heat exchange capacity roughly match.

(Effects of the Invention) As explained above, according to the present invention, the rotation speed of the fan is adjusted by a simple and inexpensive method independent from the compressor,
Since the cooling/heating capacity of the compressor and the heat exchange capacity of internal and external heat exchange can be made equal, the generation of noise caused by operating the fan at a rotation speed higher than necessary can be minimized, and There is no need to waste electricity.

In particular, in the case of broadcasting relay vehicles, there is no need to stop the air conditioner operation during broadcasting, which has an extremely large practical effect.

Although the embodiment has been described with respect to an air conditioner for a broadcast relay vehicle, the present invention can also be applied to other general vehicle air conditioners such as X-ray vehicles, medical treatment vehicles, accident treatment vehicles, security vehicles, and other vehicles that have similar problems. Noise standards are set by JIS for air conditioners for home and general commercial use, but this has not completely solved the problem of noise, and there is still a need to reduce noise levels. Therefore, it can be applied to these air conditioners as well.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing the configuration of an air conditioner according to the present invention that controls the rotation speed of the fan as well as the compressor; Fig. 2 is a system diagram of a conventional air conditioner that does not use an inverter; is a system diagram of a conventional air conditioner using an inverter. 1, ]'・AC100V input terminal 3...Compressor 4...Four-way valve 5...Internal heat exchanger 6. Meter: Fan 7: External heat exchanger 12: Inverter 13 to 17: Temperature detector 20.21: Variable resistor 22: Interlocking variable resistor 23: Semi-fixed resistor 24...Resistor 25...Switch 27...Power converter agent patent attorney Ko Sugimura Figure 3 p

Claims (1)

[Scope of Claims] 1. An air conditioner in which driving power for a compressor motor is supplied from an inverter, and driving power for a blower fan of an internal heat exchanger and an external heat exchanger is supplied from a power converter. 2. The air conditioner according to claim 1, wherein the rotational speed of the inverter and the rotational speed of the fan are controlled by an interlocking variable resistor.