JPS6383538A - Defrosting control device for air conditioner - Google Patents

Abstract

PURPOSE:To optimize the timing of completion of defrosting by detecting the recovery current level which is the sum of the current level at the moment when the set time has past and the set current level which is dependent on the power source frequency at the moment when the set time has elapsed from the start of defrosting and switching the defrosting cycle to a heating cycle by a cycle switching means when the compressor operating current is determined to have exceeded the recovery current level. CONSTITUTION:When a defrosting operation is started and the power source frequency is inputted, it is determined whether it is 50Hz or 60Hz, and the set current level dependent on the frequency is memorized, and the set time T1 starts to be counted. When T1 is determined to have elapsed, the operating current I is read by a current detection circuit 9, and the operating current I0 at the moment when T1 has elapsed is memorized by an LSI24. The sum of the set current I1 dependent on the power source frequency and the operating current I0 is memorized as the defrosting completion current I2. Then, a determination is made as to whether the operating current level I is smaller than the defrosting completion current I2. If the condition is met, a defrosting completion signal is sent out.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a defrosting control device for a separate heat pump type air conditioner. Regarding air conditioners.

Conventionally, as shown in Japanese Patent Publication No. 5B-205064, the current of the compressor during defrosting is detected, and the compressor current value at the time when the detected current value exceeds the permissible range of high-pressure refrigerant pressure is detected. A defrost control device has been developed that terminates defrosting when the temperature exceeds the limit.

Problems to be Solved by the Invention However, with such conventional technology, there is a problem that the timing of melting the frost on the outdoor heat exchanger and the timing of finishing defrosting are different, and it takes time to finish defrosting even when the frost melts. There is a problem that defrosting is not completed in a short period of time, which leads to a reduction in heating capacity and waste of electricity, resulting in a lack of economy and comfort.

Also, the use of power supply frequency, that is, 50Hz and 60Hz
In the case of Hz, the operating current of the compressor is different and the defrosting ability is different, so there is a problem that optimal defrosting cannot be performed with the same set current value.

As described above, the conventional technology has many problems, and improvements are required.

In view of the above conventional problems, the present invention provides a defrost control device that can optimize the timing of defrosting completion without sacrificing the advantages of the prior art.

Means for Solving the Problems In order to solve the above problems, the present invention, as shown in FIG. a set time detection means for detecting and outputting the elapse of time; and a set time elapsed current value detected by a current detection means for detecting the operating current of the compressor after the set time by the set time detection means has elapsed; A set current storage means that stores a set current value in advance, a frequency input means that inputs a power supply frequency, and a frequency input by the frequency input means is 50H.
- or 60Hz;
a set current value switching means for switching the set current value stored in the set current storage means based on the output of the ft number determining means;
a return current calculation storage means for adding a set current value stored in the preset current storage means to the set time elapsed current value and storing the result as a return current value; and a current value detected by the current detection means and the return current. It is composed of a determination output means for comparing the values and determining that the current value has become larger than the return current value and outputting the result, and an output means for driving the cycle switching means by the output signal of the determination output means.

Effect With the above configuration, after the set time by the set time detecting means has elapsed from the start of defrosting, the current detecting means detects the return current value which is the sum of the set time elapsed current value and the set current value according to the power supply frequency, and makes a judgment. When it is determined by the means that the compressor operating current exceeds its return current value, the cycle/L
/The defrosting cycle is switched to the heating cycle by the switching means.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 2 to 5.

FIG. 2 is a refrigeration cycle diagram showing one embodiment of the present invention.

In the figure, the refrigeration cycle includes a compressor 1 and a four-way switching valve 2.
, an indoor heat exchanger 3, a pressure reducer 4, and an outdoor heat exchanger 5 are connected in sequence. Reference numeral 6 denotes a pipe temperature detection element, which is attached to a pipe that is on the refrigerant inlet side of the indoor heat exchanger 3 during heating. In this case, during cooling operation and defrosting operation, the refrigerant flows in the direction of the solid line arrow in the figure, and during heating operation, the four-way switching valve 2 switches, so that the refrigerant flows in the direction of the broken line arrow in the figure. There is.

Furthermore, an outdoor unit is provided by the compressor 1, four-way switching valve 2, pressure reducer 4, outdoor heat exchanger 5, and outdoor blower 8).
A is configured. In addition, an operation control unit (not shown) includes a microcomputer (hereinafter referred to as microcomputer) programmed with the indoor heat exchanger 3 and the indoor blower 7, as well as a pipe temperature detection element 6, a timer function, a temperature control function, etc. ) is provided in indoor unit) B. Here, the pipe temperature detection element 6 is attached at a location away from the wind circuit where it is not affected by the air blowing from the indoor blower 7. Alternatively, it may be near indoor unit) B.

Next, the operation control circuit configuration will be explained with reference to FIG. Here, the same parts as in FIG. 2 are given the same numbers and will be explained.

In the figure, CD indicates an operation control unit and a remote control unit (hereinafter referred to as the operation unit), respectively, and the operation control unit C includes a transformer 22 that steps down the AC power supply 21, and a DC power supply that exchanges AC into DC. The generator 23 and the direct output from the DC power generator 23 are connected to a microcomputer (hereinafter referred to as I).
, SI) 24 as an input power source.
And the reference voltage generation times! 26 and a comparison circuit 28 that compares the input of the pipe temperature detection element 6, the compressor 1, the four-way switching valve 2,
It is equipped with an output circuit 29 consisting of a group of relay elements that controls the operation of the indoor blower 7 and the outdoor blower 8, an oscillation circuit 30 that creates basic timing for various signal processing of the LSI 24, and a reset circuit 31 that controls various signal processing. ing.

The current detection circuit 9 also includes an alternator 10 that can extract a current proportional to the compressor current, a rectifier circuit 11 that full-wave rectifies the current of the alternator 10, and a capacitor that smoothes the output of the rectifier circuit 11. 12, 13 and a resistor 14, a resistor 15 that stabilizes the output voltage of the alternator 10, and a resistor 16 that stabilizes the output voltage of the rectifier circuit 11.

Here, the regulator 25 is connected to the port P of the LSI 24.
1, the output circuit 29 is connected to the ports Pli to P16, the current detection circuit 9 is connected to the port P2, the comparison circuit 2B is connected to the port P31, and the oscillation circuit 30. Reset circuit 31 is baud) p41・
They are connected to P42 and P51, respectively.

Further, full-wave rectification is output from the diode bridge of the DC power generation section 23, converted into a clock signal by the inverter 32, and inputted to the p□ port.

Upon receiving the clock signal, the 50760 inside the LSI24
The frequency is determined by the Hz determining means, and a set current value is selected according to the frequency.

The reference voltage generation circuit 26 is constituted by resistors 101 and 102, and the output circuit 29 is configured by each boat P11.
~Relay element R1, R2'R3, R connected to P16
It is composed of 4, R5, and R6. Relay element R1 corresponds to a compressor, relay element R2 corresponds to a four-way switching valve, relay element R3 corresponds to an outdoor blower, and relay element R
4, R5, and R6 correspond to "low speed", "medium speed", and "high speed" speed terminals for switching the air volume of the indoor blower, respectively.

Further, 61 is an air temperature detection element that detects the intake air temperature, and 62 is an A/D equipped with a plurality of resistance groups 110 to 115.
The conversion circuit S3 is an input of the air temperature detection element 61,
The input from the A/D conversion circuit 52 is compared, and the compressor 1
This is a comparison circuit that outputs a run/stop signal.

The air temperature detection element 51 and the A/D conversion circuit 52 constitute the function of a thermostat that adjusts the indoor temperature, and
The /D conversion circuit 62 converts baud 1-P71 to P71 of the LSI 24.
74 and the output of the comparator circuit 63 are connected to baud)-PBl of the LSI 24, respectively. Since this room temperature control is not related to the gist of the present invention, detailed explanation will be omitted.

Next, the operation section is set to ``Low speed'', ``Medium speed'', ``High speed'', ``
An air volume switching operation section 41 equipped with selection switches 81 to S4 for "Stop" and switches Sll to 81 for setting the room temperature.
The room temperature setting operation section 42 includes a room temperature setting operation section 42.

The air volume switching operation section 41 and the room temperature setting operation section 42 are connected to the LSI 24 (7) baud H'61 to P66, respectively. By operating the air volume switching operation section 41 and the room temperature setting operation section 42, LSI 2
The contents of the operation are processed inside the controller 4, and the output circuit 29 and the room temperature control related circuit section are operated.

Furthermore, the relationship between the above configuration and the configuration shown in FIG. 1 will be explained. The current detection circuit 9 corresponds to current detection means, the output circuit 29 corresponds to output means, the inverter 32 corresponds to frequency input means, and the oscillation circuit 30 corresponds to LSI 2.
40 basic operating times, the LSI 24 performs operations corresponding to a set time detection means, a frequency determination means, a set current switching means, a set current storage means, and a return current calculation storage means,
Furthermore, it also corresponds to a comparison determination means for determining whether the operation is defrosting operation or heating operation.

Next, the operation from the start of defrosting to the end of defrosting will be explained with reference to FIG.

When defrosting begins, the heating cycle switches to the defrosting cycle, and the operating current drops rapidly. Then, it becomes stable after a predetermined time T1 has elapsed.

Thereafter, when the frost on the outdoor heat exchanger 5 melts, the high pressure increases and the current value also increases rapidly.

Here, when the operating current after the predetermined time T1 has elapsed from the start of defrosting is IQ, and the set current is 11, the operating current when the frost on the outdoor heat exchanger melts, that is, the defrosting end signal is The generated operating current I2 is expressed as l2=I1+I□.

Here, when the power supply frequency is 50 Hz, the current value is generally lower than when the power supply frequency is 60 Hz, as shown by the broken line in FIG. 4, and the set current value 11 becomes smaller. Therefore, 50Hz,
If the same set current value 11 is used at 60 Hz, defrosting operation will continue even if the frost melts at 50 Hz, so change the set current value 11 at 50 Hz and 601 (z) to obtain the optimal defrosting time. This ensures optimal defrosting operation.

Based on the above explanation, the control circuit shown in FIG. 3 controls the contents of the chart 70 shown in FIG.

That is, when defrosting operation is started in step 1, and the power frequency is input in step 2, 50Hz is input in step 3.
or 60Hz, and in step 4, a set current value (11) corresponding to the frequency is stored.

Then, the timer counts the opening T1 at a predetermined time (step 5). This timer count set is to ensure defrosting operation for T1 time (for example, 1 minute) from the start of defrosting operation, and is one means for preventing malfunctions due to current fluctuations.

Then, as shown in step 6, T1
When it is determined that time has elapsed, the process moves to step 7, where the current detection circuit 9 reads the operating current l, and step 8
The operating current IQ after the lapse of time T1 is stored in the LSI 24. Further, the set current 11 (for example, IA) corresponding to the power supply frequency stored in the LSI and the operating current I□ are added and stored as the defrosting end current I2 (step 9).

Then, it is determined whether the operating current I is smaller than the defrosting end current I2 (step 10). This judgment is made by LSI
24.

Then, if step 100 conditions are satisfied, step 11
The defrost end signal is generated.

Effects of the Invention As described above, according to the present invention, it is possible to accurately detect the end of defrosting by detecting the operating current during defrosting, the configuration is simple, and the end of defrosting can be detected indoors. This eliminates unnecessary defrosting time, improving economy and comfort.

That is, since the defrosting end current is obtained by adding the set current value to the operating current after a predetermined time from the start of defrosting, defrosting can always be ended at the optimal defrosting current value according to the power supply frequency.
To complete defrosting in the minimum time without being affected by differences in voltage levels depending on region. Furthermore, optimal defrosting completion detection can be performed by indoor current detection and LSI without being affected by the amount of frost, regional voltage differences, or outside temperature.

Further, the operating current is not limited to the current of only the compressor, but the same effect can be obtained as a total current including the current of the outdoor fan motor, etc.

[Brief explanation of the drawing]

Fig. 1 is a block diagram expressing the defrosting control device of the present invention using function realizing means, Fig. 2 is a refrigeration cycle diagram of an air conditioner showing an embodiment of the present invention, and Fig. 3 is a block diagram of the defrosting control device of the present invention. A circuit diagram of the defrosting control device, Fig. 4 is a characteristic diagram showing the relationship between operating current and time during defrosting in the defrosting control device, and Fig. 5 is a 70-chart showing the operation details of the defrosting control device. It is. 1... Compressor, 2... Four-way switching valve, 3
...Indoor heat exchanger, 6...Outdoor heat exchanger, 9...Current detection circuit (current detection means)
, 24... LSI (set time detection means, frequency determination means, set current switching means, set current storage means, return current calculation storage means, comparison judgment means), 29...
Output circuit (output means), 32... Frequency input means. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure/-11 pressure fanning ^ 4--FAQ River" 4 B-1-"l unit vF, 4 Figure 5

Claims (1)

[Claims] A refrigeration cycle equipped with a compressor, a four-way switching valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger, and a cycle switching means for switching between a heating cycle and a defrosting cycle, and switching between the heating cycle and the defrosting cycle. The control device that controls the system detects that a set time has passed since the start of defrosting,
A set time detection means to output, a set time elapsed current value detected by a current detection means for detecting the operating current of the compressor after a set time elapsed by the set time detection means, and a setting in which the set current value is stored in advance. a current storage means, a frequency input means for inputting a power supply frequency, a frequency determination means for determining whether the input frequency by the frequency input means is 50Hz or 60Hz, and an output of the frequency determination means stored in the set current storage means. set current value switching means for switching the set current value that has been set; return current calculation storage means for adding the set current value stored in the set current storage means to the set time elapsed current value and storing the result as a return current value; a comparison and determination means that compares the current value detected by the detection means with the return current value, determines that the current value has become larger than the return current value, and outputs the result; and the cycle switching means based on an output signal of the comparison and determination means. A defrosting control device for an air conditioner, which is equipped with an output means for driving.