JPS63251762A - Drive for gas refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is a drive device that is used for IFI of a gas refrigerator and can achieve low power consumption.

[Conventional technology]

First, a conventional gas refrigerator drive device will be explained.

Figure 5 is a diagram showing the drive device of a conventional gas refrigerator.
1) is an AC oscillator that generates sine f&, 12) is an analog power amplifier, (3) is a gas refrigerator that operates based on a thermodynamic cycle and creates a low temperature, and a magnetic circuit with a +41/ri permanent magnet. , (5) A coil wound to cross the magnetic circuit 14), 161 is a piston (f71) that moves in synchronization with the coil excited by the AC oscillator 1).
The f-1 cooler includes a heat exchanger that removes heat from the medium compressed by the piston, and the 18-inch condenser is a heat storage device that includes a heat exchanger that removes heat from the medium during expansion.

In the conventional gas refrigerator driving device described above, the coil (5) is excited by a sinusoidal AC oscillator (+1).

This is because the coil (5) is coupled with the magnetic circuit 14).

It operates in synchronization with the AC oscillator [1], receiving a force in a direction perpendicular to the direction of the magnetic flux of the a-air circuit (4).

That is, since the piston (6) is directly connected to the coil/l/+5)K, it can reciprocate according to the operation of the coil.

The frequency at which the coil 15) operates is set to be approximately equal to the natural frequency of the coil of the gas refrigerator (3), the weight of the piston, and the pressure spring force of the medium.

In this manner, the piston 61 operates, and based on this, the medium inside the piston 61 is repeatedly compressed and expanded.

When the medium is compressed, it is cooled by a cooler (7) including a heat exchanger to generate compression heat.On the other hand, when the medium expands, it is cooled by a heat storage device 18 including a heat exchanger that absorbs heat from the object to be cooled. )
This allows gas to flow.

Based on thermodynamic cycle operation, low water can be accumulated.

[Problem that the invention seeks to solve]

Conventional gas refrigerator drive devices such as those mentioned above are always operated in the region of the natural vibration characteristics of the gas refrigerator, so the natural vibration characteristics greatly affect power consumption and cannot guarantee stable operation. There wasn't.

If we wanted to achieve even lower power consumption, it would be difficult to do so because of the inherent imaging characteristics of gas refrigerators.

The above gas refrigerator operates at a natural frequency determined by the coil, piston weight, and medium pressure spring force, but the amplitude value of the natural vibration point can also be used to determine whether it can operate smoothly, resulting in power consumption. The increase and decrease in

Also, analog linear amplifiers are usually used as power amplifiers to drive gas refrigerators.

If the natural vibration characteristics of a gas refrigerator are poor, it is necessary to increase the drive capacity of the power amplifier in order to maintain cooling operation, which places a burden on the power amplifier and generates heat.

Naturally, the performance of the power amplifier will be poor (and the power consumption will also increase).

This invention was made to solve this problem, and aims to minimize the amount of power supplied by the power supply by using a current resonance circuit for the output of the power amplifier and combining it with the resonance characteristics of the gas refrigerator. There is.

[Means for solving problems]

By giving the power amplifier output a current resonance characteristic, the gas refrigerator drive circuit according to the present invention makes it possible to improve the efficiency of the operation of the gas refrigerator, as well as the specific number of motions of the gas refrigerator.

According to the conventional method, the gas refrigerator was operated only at its natural frequency, making it difficult to reduce power consumption.

In addition, by changing the power amplifier that drives the gas refrigerator from a conventional linear amplifier to a digital one that controls ON and OFF, the waveform to be controlled changes from a sine wave to a rectangular wave, eliminating the problem of malfunctions due to waveform distortion and improving control. It also becomes easier.

Although the voltage is on/off controlled, the current flowing through the resonant circuit has a waveform close to a sine wave, so the on/off control power amplifier consumes very little power and is suitable for gas refrigerators, which have advantageous characteristics against electromagnetic interference. A driving device can be provided.

[Effect]

The use of a resonant circuit in this invention means that the driving power is 1/2 to 17 times lower than that of a conventional gas refrigerator that operates only using its own natural frequency. It also becomes.

There is also a method that provides the same functionality without using such a resonant circuit.

For example, using a feedbank system in a conventional gas refrigerator,
There was a way to create a closed loop.

In this method, the damping coefficient of the loop is set around O, l to create a state that is very easy to operate.

This method works easily by applying an external signal.

This method has one problem in terms of cost because the number of parts increases and the loop becomes complicated.

By having a resonant circuit, this invention has the advantage of being able to maintain performance equivalent to that of a closed loop, reducing the number of parts, and reducing costs.

〔Example〕

FIG. 1 shows an embodiment of this patent, and (3) is the same as FIG. 5. (91 is a square wave oscillator with positive and negative amplitudes based on zero, αC is a digital power amplifier that can be turned on and off according to the oscillator (9), and power amplifier I
This is a circuit that can generate current resonance for IQ output.

FIG. 2 is a diagram showing the natural vibration characteristics of a gas refrigerator and the resonance characteristics of a resonant circuit, with the vertical axis representing amplitude and the horizontal axis representing frequency.

In this invention, a signal output from a square wave oscillator (9) is applied to the power amplifier OC, and the power amplifier 1 is turned on and off according to the signal from the square wave oscillator (9), and is applied to the resonant circuit Uυ.

The resonance circuit 1B has a resonance point almost equal to the natural frequency of the gas refrigerator, and when the power amplifier uIl is on.

Causes alpha flow resonance. In other words, the output voltage is a square wave, but
The flowing current exhibits the amplitude characteristics of the resonant current waveform.

This resonant circuit is composed of parts that can resonate with the coil (5) of the Crt refrigerator (3).

Figure 2 shows that the maximum force can be produced by combining the resonance characteristics generated by the resonance circuit all and the gas refrigerator (31).

Figure 3 shows the conventional power amplifier output waveform.

FIG. 4 shows the power amplifier output waveform of the embodiment.

Figure 3 shows the voltage and current waveforms driven by sine wave amplitude drive, but since a linear power amplifier is usually used, all the power other than that supplied to the gas refrigerator is consumed by the power amplifier. .

Therefore, the power consumption of the power amplifier varies depending on the performance of the gas refrigerator.

In particular, fluctuations in the performance of gas refrigerators and the effects of environmental conditions such as humidity are making it difficult to reduce the power consumption of power amplifiers.

On the other hand, the power amplifier of the embodiment shown in FIG. 1 is controlled by a rectangular wave, and the power amplifier circuit design is relatively simpler than that of the IJ near power amplifier shown in FIG.

Since the current waveform has resonance characteristics, the maximum current value is approximately the value obtained by dividing the power supply voltage by the internal resistance.

Also, the maximum current @ of the linear power amplifier shown in Fig. 3 is the value obtained by dividing the power supply voltage by the inductance plus the internal resistance.

Naturally, the power amplifier shown in Figure 4 can flow a larger current.

In other words, the force (force?) acting on the coil of the gas refrigerator is given by the following formula.

From F = B L: Magnetic flux density L: Coil width: Current flowing through the coil When using the IJ near power amplifier shown in Figure 3 and the digital power amplifier shown in Figure 4 in a refrigerator of the same type ( Naturally, the latter digital power amplifier can output a much larger power and has an advantage when it comes to the current (W).

Depending on the load conditions of the power Ftri refrigerator, it will vary from 2 to 0 times.

In addition, since gas refrigerators originally adjust the medium pressure inside the piston, coil mass, etc. to make it easier to oscillate at the natural frequency, as shown in Figure 4, the current resonance of the digital power amplifier causes large chips and When the characteristic perturbation number of the gas refrigerator is added.

It becomes possible to fully drive the gas refrigerator with low α force.

The digital power amplifier shown in Figure 4 uses 1b control using a square wave, so even if the power amplifier is turned on and off and multiplied by the transistor 0Nli voltage and the current supplied to the load, it is on the order of several W, and no heat generation effect is observed ( Become.

Also, since this digital power amplifier output has current resonance, is there current interference? can be kept to a minimum.

In other words, the electromagnetic interference is determined by the rise/fall of the Fi plate waveform, but the current does not rise at the rise/fall of the digital power amplifier Hill voltage, and its energy is very small, so the interfering energy is small. This method is also considered to be effective for high-power refrigerators.

Note that the current resonant circuit of the above embodiment uses condensation, resistance, and inductance that can electrically resonate.

A single circuit of composite components such as an oscillator and active elements, and mechanical elements, components, springs, etc. may be used.

〔Effect of the invention〕

As explained above, the present invention makes it possible to create a gas refrigerator with low power consumption and high cooling capacity by using the gas refrigerator's natural frequency and current resonance circuit.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG.
Figure 3 shows the frequency characteristics of the gas refrigerator and resonant circuit of the embodiment. Figure 3 shows the output voltage and current characteristics of the conventional power amplifier. Figure 4 shows the output voltage and current characteristics of the power amplifier of the embodiment. ,? The figure shown in FIG. 5 is a schematic diagram of a conventional drive device for a gas refrigerator. In the figure, Ill fj AC oscillator, (2) is +7 near power amplifier, (3) is gas refrigerator, (4) is sharpening circuit, (5) is coil,! 6) is a piston, (7) is a cooler, and 181 is a heat storage device. (9) is a square wave generator, and the rabbit is a digital power amplifier. aυ is a resonant circuit. Note that the same or corresponding parts in FIG. 9 are designated by the same reference numerals.

Claims (1)

[Claims] In a drive device for a gas refrigerator using the principle of a Stirling cycle engine, a square wave oscillator is set to a frequency near a natural frequency at which the gas refrigerator easily operates;
a power amplifier that can be turned on and off according to an AC oscillator to excite the gas refrigerator; a resonant circuit that can cause current resonance at a point where the output of the power amplifier is approximately equal to the natural frequency of the gas refrigerator; The present invention is characterized by comprising a gas refrigerator capable of driving the piston in accordance with the frequency of the AC oscillator by coupling a coil directly connected to the piston and a magnetic circuit to form a low-temperature space through thermodynamic cycle operation. Drive device for gas refrigerator.