JPS616531A - Temperature protector of frequency control air conditioner - Google Patents

Abstract

PURPOSE:To make it possible to positively protect the temperature of a reactor, to materialize downsizing, lightening or reduction of capacity of a reactor, and to simplify the blasting and radiating stracture in the vicinity of the reactor, by detecting the reactor temperature by temperature detecting means provided in the reactor and controlling the operation frequency of a compressor. CONSTITUTION:At the time of starting, when a timer circuit contained in an LSI4 is set at a time n=0, the operation is started, and the periodical temperature detection of a reactor 9 is started by a thermistor 1. In a comparison circuit contained in an LSI4, a detected temperature (t) is compared with a set temperature T. If t<=T, a signal from the comparison circuit is output to a variable frequency outputting circuit through a traveling circuit, and a power transistor 7 is operated, the compressor 7 being operated at f1Hz. When a thermal load is large, the operation frequency of the compressor is large, and the operation current is also large. Therefore, the quantity of heat generated of the reactor 9 becomes large, and the temperation relation becomes t>T. The compressor is operated at f2Hz in which the frequency is lower than f1Hz.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a temperature protection device for a power factor improving reactor of a frequency-controlled air conditioner whose operation control device is equipped with a microcomputer.

Conventional configuration and its problems Reactors for power factor improvement in frequency-controlled air conditioners (hereinafter simply referred to as reactors) have a large heat load in the room due to their self-impedance, and require large cooling or heating capacity. In such a case, if the compressor is operated at a high frequency, the operating current will increase and the amount of heat generated will increase.

For this reason, temperature rises have traditionally been suppressed by increasing the capacity of the reactor or by considering ventilation and heat conduction near the reactor, but as a result, the reactor has become larger and heavier, and the structure near the reactor has become smaller. This method has disadvantages such as complication.

OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to make the reactor smaller and lighter, simplify the ventilation/heat dissipation structure, and protect the temperature of the reactor.

Structure of the Invention In order to achieve this object, the present invention, as shown in FIG. The timing is compared by a comparing means, and the operating frequency of the compressor is sequentially shifted by the electrical signal from the comparing means, and the operating frequency of the compressor is controlled step by step by the electrical signal of the shifting means. It consists of a storage means for storing information and an output means for operating the compressor at a frequency specified by the electrical signal stored in the storage means, and the frequency of the compressor is controlled according to the temperature of the reactor under high load conditions. be.

With the above configuration, the reactor can be made smaller and lighter, the ventilation and heat dissipation structure in the vicinity of the reactor can be simplified, and temperature protection of the reactor can be ensured.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 to 4 of the accompanying drawings.

FIG. 2 is a compressor frequency control circuit diagram, which includes a thermistor 1 that detects the temperature t of the reactor, a temperature detection bag device 2 that converts the detected temperature t into an electric signal and outputs it, and an electric signal of the temperature set value T. an oscillation device 5 that slopes a pulse signal of a constant frequency to a microcomputer 4 (hereinafter referred to as LSI), a comparison circuit that compares and determines the electrical signal from the temperature detection device 2 and the electrical signal of the temperature set value T; A timer circuit that provides the timing of comparison, a variable frequency output circuit (multiple frequency dividing circuits) that counts the pulse signal of the oscillator 5 and controls the operating frequency of the compressor 6 in stages, and an electrical signal from the comparison circuit. LS that has a built-in transition circuit, etc. that outputs an electrical signal that sequentially shifts the operating frequency of the compressor 6
I4, an output device using a power transistor 7 that generates a three-phase AC power supply of a specified frequency according to the electric signal output from the LSI 4 and operates the compressor 6; It is comprised of a rectifier circuit 8 for supplying the power, an accelerator 9 within the rectifier power supply circuit 8 which functions to improve the power factor, and the like.

Here, to explain the relationship between the block diagram shown in FIG. 1 and the control circuit diagram shown in FIG. The comparison, timer, transition, and variable frequency output circuits built into I4 correspond to comparison, time measurement, transition, and storage means, respectively, and the power transistor 7 corresponds to output means.

Next, the operation of the control circuit having the above configuration will be explained with reference to the flowchart of FIG. 3 and the time chart of FIG. 4.

At the start of operation, when the built-in timer circuit in LS I4 turns ○N, that is, the time is set to n20, the air conditioner starts operating, and thermistor 1 starts periodically detecting the temperature of accelerator 9. . Then, the detected temperature t and the set temperature T are compared in the comparison circuit built in the LSI 4, and if t≦T, the signal from the comparison circuit is outputted to the variable frequency output circuit via the transition circuit, and the power transistor 7 is activated. The compressor 7 is driven at fI Hz.

As the operation progresses, the timer continues to count, and when the heat load is large, the operating wave number of the compressor is large and the operating current is also large, so the amount of heat generated by the reactor 9 increases and the detected temperature t gradually rises.

Then, when the time reaches n=n1+1i, the temperature relationship becomes f>T, and the mode shifts to operation mode (2). At this time, the compressor is operated at f211z, which is a lower frequency than fIHz.

As a result, the operating current decreases φ, so the amount of heat generated by the reactor 9 decreases, and the detected temperature t from the reactor 9 decreases with the passage of time (n=n1+2 to n1+3). At time n=n14-3, t≦T and the temperature of the reactor 9 has decreased, so the operation shifts to fast mode again and the compressor is operated at a high frequency.

With the above control, temperature control of the reactor can be ensured, the reactor can be made smaller and lighter (lower capacity) than conventional reactors, and the ventilation and heat dissipation structure near the reactor can be simplified.

In addition, the time chart in Fig. 5 shows that the two temperature wave numbers are lowered by one step (lower by one step at n=n1+1, n=nl+2), and when the temperature of reactor 9 becomes below T1, the frequency is increased by one step ( n=n1+4, n=n
1-1-5), and is an example in which consideration is given to obtaining the maximum capacity of the air conditioner while controlling the temperature of the reactor 9. Similar effects can be obtained by using a combination of a plurality of temperature settings and time control in this manner and changing the operating frequency of the compressor in multiple stages.

Effects of the Invention As is clear from the above embodiments, the temperature protection device for a frequency-controlled air conditioner according to the present invention uses temperature detection means provided in the reactor (which detects the reactor temperature and controls the operating frequency of the compressor). This not only makes it possible to ensure temperature protection of the reactor, but also allows the reactor to be made smaller, lighter, or smaller in capacity, and has excellent effects such as allowing ventilation and heat dissipation structures near the reactor to be made of carp. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram expressing the steering wheel temperature protection device of the present invention as a function realizing means, FIG. 2 is an electric circuit diagram of an operation control device equipped with a microcomputer in the τ embodiment of the present invention, and FIG. FIG. 4 is a flow chart and a time chart showing one embodiment of the reactor temperature protection control, respectively, and FIG. 5 is a time chart corresponding to FIG. 4 showing another embodiment of the present invention. 1...Thermistor, 2...Temperature detection device, 3...Resistance device, 4...Microcomputer, 6.Compressor, 7
...Power transistor, 9...Reactor.

Claims (1)

[Claims] A compressor whose rotation speed varies according to the operating frequency, a four-way valve,
A heat pump type refrigeration cycle is constructed by connecting an indoor heat exchanger, a pressure reducing device, an outdoor heat exchanger, etc. in a ring, and further detects the temperature of the power factor improving reactor of the compressor and converts it into an electrical signal. temperature detection means for outputting, and at least one
a comparison means for comparing electrical signals of two temperature set values and outputting a control signal; a timing means for providing a timing for comparing the temperature set value and the detected temperature; a transition means for sequentially shifting the operating frequency of the compressor; A frequency configured by a storage means storing a variable frequency output mode for controlling the operating frequency of the compressor in stages according to an electric signal from the storage means, and an output means for driving the compressor at a specified frequency according to the electric signal from the storage means. Temperature protection device for controlled air conditioners.