JPH0535328B2 - - Google Patents

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, and particularly to a defrosting control device for a separate heat pump type air conditioner. Regarding air conditioners.

Conventional technology As disclosed in Japanese Patent Application Laid-Open No. 58-205064, the current of the compressor during defrosting is detected, and the compressor current value is determined at the point when the detected current value exceeds the permissible range of high-pressure refrigerant pressure. A defrosting control technology has been developed that terminates defrosting when the temperature exceeds this limit.

Problems to be Solved by the Invention However, in 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 were problems in that defrosting was not completed in a short time, leading to a reduction in heating capacity and waste of electricity, resulting in a lack of economy and comfort.

Also, the difference in power supply frequency, that is, 50Hz and
In the case of 60Hz, the operating current of the compressor differs, resulting in a difference in defrosting ability, so there was a problem that optimal defrosting could not 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 defrosting 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 that detects and outputs the elapse of time, and a set time elapsed current value detected by a current detection means that detects the operating current of the compressor after the set time has elapsed by the set time detection means. a set current storage means that stores a set current value in advance; a frequency input means that inputs a power supply frequency; a frequency determination means that determines whether the frequency input by the frequency input means is 50Hz or 60Hz; a set current value switching means for switching the set current value stored in the set current storage means by an output, and a set current value stored in the set current storage means added to the set time elapsed current value and stored as a return current value. a return current calculation storage means for comparing the current value detected by the current detection means with the return current value, and a judgment output means for determining and outputting that the current value has become larger than the return current value; It is constructed of an output means for driving the cycle switching means based on an output signal from the 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. When the determining means determines that the compressor operating current exceeds the return current value, the cycle switching means switches the defrosting cycle to the heating cycle.

Embodiment An embodiment of the present invention will be described below 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 is constructed by sequentially connecting a compressor 1, a four-way switching valve 2, an indoor heat exchanger 3, a pressure reducer 4, and an outdoor heat exchanger 5. 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.

Further, the compressor 1, the four-way switching valve 2, the pressure reducer 4, the outdoor heat exchanger 5, and the outdoor blower 8 constitute an outdoor unit A. In addition, an operation control unit (not shown) includes a microcomputer (hereinafter referred to as microcomputer) programmed with the indoor heat exchanger 3 and 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, the location 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, C and D indicate an operation control section and a remote control section (hereinafter referred to as operation section), respectively, and the operation control section C includes a transformer 22 that steps down the AC power supply 21, and a DC power supply that exchanges AC into DC. A generator 23 and a microcomputer (hereinafter referred to as LSI) 2 which receives direct current from the DC power generator 23.
4, a comparison circuit 28 that compares the inputs of the reference voltage generation circuit 26 and the pipe temperature detection element 6, and the operation of the compressor 1, four-way switching valve 2, indoor blower 7, and outdoor blower 8. an output circuit 29 consisting of a group of relay elements for controlling the
It is equipped with 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.

The current detection circuit 9 also includes an alternator 10 that can extract a current proportional to the compressor current, and an alternator 10 that can extract a current proportional to the compressor current.
A rectifier circuit 11 that performs full-wave rectification of a zero current, and capacitors 12 and 1 that smooth the output of this rectifier circuit 11.
3 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 _P1 of the LSI 24, and the output circuit 29 is connected to the ports _P11 to _P16.
and the current detection circuit 9 is connected to the port
_P2 , the comparison circuit 28 is connected to port _P31 , and the oscillation circuit 30 and reset circuit 31 are connected to ports _P41 , _P42 , and _P51, respectively.

Further, the full-wave rectification is taken out from the diode bridge of the DC power generation section 23, converted into a clock signal by the inverter 32, and inputted to the _P0 port.
After receiving that clock signal, the 50/60 inside the LSI24
The frequency is determined by the Hz determination means, and a set current value is selected according to the frequency.

The reference voltage generation circuit 26 includes a resistor 101,
102, and the output circuit 29 is
Relay element R ₁ connected to each port P ₁₁ to P ₁₆ ,
It is composed of R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ . Relay element R ₁ corresponds to a compressor, relay element R ₂ corresponds to a four-way switching valve, relay element R ₃ corresponds to an outdoor blower, and relay elements R ₄ , R ₅ , R ₆ each correspond to the air volume of an indoor blower. Corresponds to the "low speed", "medium speed", and "high speed" speed terminals for switching.

Further, 51 is an air temperature detection element for detecting the intake air temperature, 52 is an A/D conversion circuit including a plurality of resistor groups 110 to 115, and 53 is an input of the air temperature detection element 51 and the A/D conversion circuit 52. This is a comparison circuit that compares the inputs from the compressor 1 and outputs an operation/stop signal for the compressor 1.

The air temperature detection element 51 and the A/D conversion circuit 5
2 constitutes the function of a thermostat that adjusts the indoor temperature, the A/D conversion circuit 52 is connected to ports P ₇₁ to P ₇₄ of the LSI 24, and the output of the comparison circuit 53 is
Each is connected to port _P81 of LSI24.
Since this room temperature control is not related to the gist of the present invention, detailed explanation will be omitted.

Next, the operation part D selects "low speed", "medium speed", "high speed",
An air volume switching operation section 41 equipped with "stop" selection switches S ₁ to S ₄ and a switch for setting the room temperature.
It is composed of a room temperature setting operation section 42 equipped with _S11 to _S14 . The air volume switching operation unit 41 and the room temperature setting operation unit 42 are connected to ports P ₆₁ to _{P 66} of the LSI 24.
are connected to each. By operating the air volume switching operation section 41 and the room temperature setting operation section 42, the operation contents are processed inside the LSI 24, 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, the oscillation circuit 30 creates the basic operating time of the LSI 24, and the LSI 24 has set time detection means, frequency determination means, set current switching means, set current storage means, and return current calculation storage. It performs an operation corresponding to a means, and 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 a predetermined time T ₁ has elapsed from the start of defrosting is I ₀ , and the set current I is ₁ , the operating current when the frost on the outdoor heat exchanger melts, that is, the end of defrosting. The operating current I ₂ that generates the signal is I ₂
It is expressed as =I ₁ +I ₀ .

Here, when the power supply frequency is 50 Hz, the current value is generally lower than when it is 60 Hz, as shown by the broken line in FIG. 4, and the set current value _I1 is smaller. By the way, 50
If the same set current value I ₁ is used for 50 _Hz and 60 Hz, defrosting operation will continue even if the frost melts. to ensure optimal defrosting operation.

Based on the above explanation, the control circuit shown in FIG. 3 controls the contents of the flowchart shown in FIG. 5.

That is, the defrosting operation is started in step 1,
When the power supply frequency is input in step 2, it is determined whether it is 50Hz or 60Hz in step 3, and the set current value _I1 corresponding to the frequency is stored in step 4. Then, the timer counts a predetermined time _T1 (step 5). This timer count set is to ensure defrosting operation for _T1 hours (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, in LSI24
When it is determined that ₁ hour has passed, the process moves to step 7.
The current detection circuit 9 reads the operating current I, and in step 8 the operating current I ₀ after T ₁ hour has passed is determined.
It is stored in the LSI24. Furthermore, the setting current I ₁ according to the power supply frequency stored in the LSI (for example
1A) and the operating current I ₀ are added to obtain the defrosting end current I ₂
(Step 9).

Then, it is determined whether the operating current I is smaller than the defrosting end current _I2 (step 10). This determination is made by the LSI 24.

When the conditions of step 10 are satisfied, the process moves to step 11 and a defrosting end signal is generated.

Effects of the Invention As described above, according to the present invention, the operating current during defrosting can be detected to accurately detect the end of defrosting, the configuration is simple, and the end of defrosting can be detected indoors. , unnecessary defrosting time can be omitted, and economy and comfort can be improved.

In other words, since the defrost end current is determined 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 depending on the power supply frequency, which can vary depending on the region. To complete defrosting in the minimum time without being affected by differences in voltage levels. In addition, indoor current detection is possible without being affected by the amount of frost, regional voltage differences, or outside temperature.
Optimal defrosting completion detection can be performed using LSI.

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 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 flowchart showing the operation details of the defrosting control device. be. 1... Compressor, 2... Four-way switching valve, 3... Indoor heat exchanger, 5... Outdoor heat exchanger, 9... Current detection circuit (current detection means), 24... LSI (setting 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.

Claims (1)

[Claims] 1. 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 a cycle switching means for switching between a heating cycle and a defrosting cycle. In a control device that controls switching, a set time detection means detects that a set time has elapsed from the start of defrosting and outputs an output, and a current that detects the operating current of the compressor after the set time has elapsed by the set time detection means. A set current storage means that stores the set time elapsed current value detected by the detection means, a set current storage means that stores the set current value in advance, a frequency input means that inputs the power supply frequency, and whether the input frequency by the frequency input means is 50 Hz or 60 Hz. 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 frequency determination means; a return current calculation storage means for adding the set current value set and storing the result as a return current value, and comparing the current value detected by the current detection means and the return current value, and detecting that the current value has become larger than the return current value. What is claimed is: 1. A defrosting control device for an air conditioner, comprising a comparison and determination means for determining and outputting a result, and an output means for driving the cycle switching means based on an output signal of the comparison and determination means.