JPH0427456B2 - - 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, and in particular, to detect the end of defrosting of an outdoor heat exchanger indoors. Regarding air conditioners.

Conventional technology As shown in Japanese Patent Publication No. 58-205064, the current of the compressor during defrosting is detected, and the compressor current value at the point when the detected current value exceeds the permissible range of high-pressure refrigerant pressure is detected. A defrost control technology has been developed that terminates defrosting when the limit is exceeded.

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

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

In view of the above-mentioned 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 return current calculation storage means that adds the set current value stored in the set current storage means to the set time elapsed current value and stores the result as a return current value; judgment output means for comparing the current value detected by the current detection means with the return current value, determining that the current value has become larger than the return current value and outputting the result; and cycle switching based on the output signal of the judgment output means. It is composed of an output means for driving the means.

Effect With the above configuration, after the set time by the set time detection means has elapsed from the start of defrosting, the current detection means detects the return current value which is the sum of the set time elapsed current value and the set current value, and the determination means detects the return current value, which is the sum of the set time elapsed current value and the set current value. When it is determined 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. Further, an operation control unit (not shown) includes a microcomputer (hereinafter abbreviated 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 installed 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 unit and a remote control unit (hereinafter referred to as operation units), 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 converts AC into DC. A generator 23 and a microcomputer (hereinafter referred to as LSI) 2 that outputs 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 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 to be controlled, and the VSI 2
An oscillation circuit 30 that creates basic timing for various signal processing in step 4, and a reset circuit 31 that controls various signal processing.
Equipped with:

The current detection circuit 9 also includes a current transformer 10 that can extract a current proportional to the compressor current, and a current transformer 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 current transformer 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
The comparator circuit 28 connected to _P2 is connected to port _P31 , and the oscillation circuit 30 and reset circuit 31 are connected to ports ₄₁ , _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.

The reference voltage generation circuit 26 includes a resistor 101,
102, and the output circuit 29 is
Relay element _R1 connected to each port _P11 to _P16
It is composed of R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ . Relay element R ₁ corresponds to the compressor, relay element R ₂ corresponds to the four-way switching valve, relay element R ₃ corresponds to the outdoor blower, and relay elements R ₄ , R ₅ , R ₆ correspond to the air volume of the indoor blower. "Low speed", "Medium speed",
Corresponds to the "high speed" speed terminal.

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 temperature setting switch.
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,
Further, the oscillation circuit 30 creates a basic operating time for the LSI 24, and the LSI 24 performs operations corresponding to a set time detection means, a set current storage means, and a return current calculation storage means, and further determines whether it is a defrosting operation or a heating operation. It also corresponds to a comparative judgment means.

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. Generate a signal. Operating current I ₂ is I ₂
It is expressed as =I ₁ +I ₀ .

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,
A timer counts a predetermined time _T1 (step 2). 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 3, when the LSI 24 determines that T ₁ hour has elapsed, the process moves to step 4, where the current detection circuit 9 reads the operating current I, and in step 5, when T ₁ hour has elapsed, The operating current I ₀ is stored in the LSI 24 . Further, the set current I ₁ (for example, 1 A) stored in the LSI and the operating current I ₀ are added and stored as the defrosting end current I ₂ (step 5).

Then, it is determined whether the operating current I is smaller than the defrosting end current _I2 (step 7). This determination is made by the LSI 24.

When the conditions of step 7 are satisfied, the process moves to step 8 and a defrosting 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, the completion of defrosting can be detected indoors, unnecessary defrosting time can be omitted, and economy and comfort can be improved.

In other words, in order to obtain the defrosting end current by adding the set current value to the operating current after a predetermined time from the start of defrosting,
It is possible to always finish defrosting at the optimal defrosting current value, and it is determined by the defrosting end current value so that defrosting can be finished in the minimum time without being affected by differences in voltage levels depending on the region. Optimum defrosting completion detection can be performed by indoor current detection and SLI without being affected by the amount of defrost, regional voltage differences, or outside temperature.

Furthermore, the operating current is not limited to the current of only the compressor, but can be similarly effective as a total current including the current of the outdoor fan motor, etc.

[Brief explanation of drawings]

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 contents of the defrosting control device. be. 1... Compressor, 2... Four-way switching valve, 3... Indoor/outdoor heat exchanger, 5... Outdoor heat exchanger, 9... Current detection circuit (current detection means), 24... LSI (setting time detection means,
setting current storage means, return current calculation storage means, comparison and determination means), 29...output circuit (output 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 current value that has elapsed over a set time detected by the detection means; a set current storage means that stores the set current value in advance; A return current calculation storage means for storing a return current value, and a comparison for comparing the current value detected by the current detection means with the recorded current value, determining that the current value has become larger than the return current value, and outputting the result. A defrosting control device for an air conditioner, comprising: a determination means; and an output means for driving the cycle switching means based on an output signal of the comparison and determination means.