JPS62172141A - Defrosting control device for air-conditioning machine - Google Patents

Abstract

PURPOSE:To obtain a defrosting control device capable of being simplified in the constitution thereof by a method wherein the defrosting control device is provided with a deciding means, deciding switching from heating cycle into defrosting cycle, and a selective output means, controlling refrigerating cycle from heating operation to defrosting operation in accordance with the output of the judging means. CONSTITUTION:A frequency deciding means in a LSI24 decides an electric source frequency by a waveform signal from an inverter IC circuit 33 whether it is 60Hz and when it is 60Hz, the output side port P21 of the LSI24 is made Hi and a reference voltage, generated by the divided voltage of resistors 101, 102, is elevated while a set pipeline temperature t1 is changed in accordance with the electric source frequency of 50Hz or 60Hz. Heating operation is started and a pipeline temperature (t) is read by a pipeline temperature detecting element 6. A comparator 28 decides whether the pipeline temperature (t) is lower than the set pipeline temperature t1 and when a condition is satisfied, defrosting operation is started. The relay elements R1.R2.R3.R4 of an output circuit 29 are operated, a four-way changeover valve 2 is switched, a compressor 1 is stopped for a given time in accordance with necessity, an indoor fan 7 as well as an outdoor fan 8 are stopped and defrosting is effected by cooling cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to a defrosting control device for a separate heat pump type air conditioner, and is particularly capable of detecting frost formation on an outdoor heat exchanger indoors. Fill the air conditioner.

BACKGROUND ART Conventionally, as shown in Japanese Patent Publication No. 59-34255, the state of frost on an outdoor heat exchanger is detected based on both the temperature change of the indoor heat exchanger and the indoor temperature change. Technology to control heating operation and defrosting operation has been developed.

Problems to be Solved by the Invention However, with this conventional structure, there is a problem in that a plurality of temperature detection elements are required, resulting in a plurality of circuits. Furthermore, in air conditioners, the amount of air blown indoors is usually set variably, and for this reason, adding a wind correction means to the conventional technology would further complicate the circuit. I end up.

Moreover, since this configuration detects the temperature of the gas-liquid mixed refrigerant while it is flowing through the heat exchanger, the temperature change between frost formation and unconfirmed frost is small, and it is necessary to perform the W wearing judgment in a minute range. However, there is a problem that the detection accuracy is unstable.

In addition, the compression function power differs between 50 Hz and 60 Hz depending on the power supply frequency, and generally higher pressure is higher at 60 Hz, and even at the same indoor heat exchanger temperature, 50 Hz and 60 Hz
The degree of frost formation on the outdoor heat exchanger was different between z and 60 Hz, and appropriate defrosting and I-setting were not possible.

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

Misfire r! In view of the above-mentioned conventional problems, the IEI is a defrosting system 1 that can simplify the configuration without sacrificing the advantages of the conventional technology.
[It provides a headdress.]

Question J: Unsuccessful means to solve the problem F'! As shown in the first diagram, A is a control device for controlling the refrigeration cycle from a heating cycle to a defrosting cycle, and a temperature detection means for detecting the temperature of a pipe connected to the refrigerant inlet side of the indoor heat exchanger;
When you input the set temperature storage means that stores the boundary value temperature for switching the heating cycle to the defrosting cycle and the power supply frequency,
frequency discrimination means for discriminating different frequencies of the power supply based on the output from the frequency clock input means; and boundary value temperature switching for switching the boundary value temperature of the set temperature storage means based on the output signal from the frequency-1 different means. and a boundary value decrease signal from a comparison means that detects and outputs that the temperature detected by the temperature detection means has fallen below the boundary value temperature stored in the set temperature storage means, the heating cycle is switched from the heating cycle to the defrosting cycle. and a selection output means for controlling the refrigeration cycle from heating operation to defrosting operation according to the output of the determination means.

Operation With this configuration, the defrosting operation is controlled according to the set temperature storage means that stores the boundary value temperature according to the power supply frequency and the detected by-product of the temperature detection 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 an 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 humidity detection element, which is attached to a pipe that is on the refrigerant inlet side of the indoor heat exchanger 3 (condenser) during heating. In this case, during heating 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 is switched so that the refrigerant flows in the direction of the broken line arrow in the figure.

Further, the E-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 (hereinafter referred to as LSI) having a microcomputer (hereinafter abbreviated as LSI) programmed with the indoor heat exchanger 3 and the indoor blower 7, a pipe temperature detection element 6, a temperature adjustment function, a judgment function, etc.
(not shown) is provided with an indoor unit BK. 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 the indoor unit B.

Next, referring to FIG. 3, we will explain the operation 1 [control circuit structure exit 1]. 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 telephone 21, and a transformer 22 that converts AC into DC. A DC voltage generator 23, a regular 25 which uses the DC from the DC power generator 23 as an input or source of the LSI 24, a reference voltage generator 26,
1) 1 setting circuit 27 for switching the operating temperature at which 2NF is performed, the reference voltage generation circuit 26, and the defrosting setting circuit 2.
A comparison circuit 28 that compares the reference composite input of 7 and the input of the pipe temperature detection element 6, and a relay element group that controls the operation of the E, TA machine 1, four-way switching valve 2, indoor method, air volume 7, and outdoor blower 8. It is equipped with an output circuit 29, a generation circuit 30 that creates basic timing for various signal processing of the LSI 24, and a reset circuit 31 that controls various signal processing. Here, the regulator 25 is connected to the boat P1 of the LSI 24, the output circuit 29 is connected to the boats P11 to P16, respectively, and a defrost setting circuit 271-t that determines the operating temperature point at which heating operation is switched to defrosting operation Port P21
The comparator circuit 28 is connected to port 1-R3, and further connected to the transmitter circuit 30, the reset circuit 7) circuit 31 port P4
1 ・Connected to R42 and R51 respectively.

The reference electron generation circuit 26 is composed of resistors 101 and 102, the defrost setting circuit 27 is composed of a resistor 103 connected to the boat P21, and the trench output circuit 29 is connected to each boat P11 to P16. Relay element R1
・R2・R3・R4・R5゛+(1ζ) is collected from R6.Relay element R1 corresponds to the compressor, and relay element R
2 corresponds to a four-way switching valve, relay element R3 corresponds to an outdoor blower, and relay elements R4, R5, and R6 respectively control the speed temperature of "low speed", "medium speed", and "high speed" to switch the air volume of the indoor fan. Corresponds to a terminal.

Furthermore, an inverter IC circuit 33 is connected to the port Po of the LSI 24, and inputs a waveform signal that has been full-wave rectified by the DC power generation section 6f7 to the LSI 24. Therefore, the LSI 24 determines whether the power supply frequency & is, for example, 50 Hz or 60 Hz, based on the period of this waveform signal, outputs the result to the boat P21, operates the defrost setting circuit, and sets the standard for the comparison circuit 2 days. Change the synthesis input. In this embodiment, when a high frequency 'e of several 60 Hz is detected, the boat P21 outputs "Hi J", increases the reference composite input voltage, and increases the boundary value temperature.

Further, 51 is an air temperature detection element for detecting the temperature of the intake air, 52 is a plurality of resistor groups IIO to 115 (1!G side A/D f conversion circuit, 53 is the air temperature detection element 51
This is a comparison circuit that compares the input from the A/D conversion circuit ms2 with the input from the A/D conversion circuit ms2, and outputs an operation/stop signal for the compressor 1.

The air temperature detecting element 51 and the A/D conversion circuit 52 constitute a function of a height-mostat that adjusts the indoor temperature.
The /D conversion circuit 52 connects the ports P71 to P7 of the LSI 24.
4 and the output of the comparison circuit 53 are respectively connected to the port P81 of the LSI 24. A detailed explanation of this room temperature control will be omitted since it does not relate to the main point of the failure-j.

Next, enter "Low speed", "Medium speed", "High speed" in the operation 64 ID.
- Room temperature setting operation with the air volume change operation section 41 equipped with "stop" selection switches 81 to S4 and switches 811 to S14 for setting the power supply.
The fin is composed of 1ζ42. The wind 1j1 switching operation section 41 and the room temperature setting operation section 42 are connected to :F of the LSI 24.
: - connected to P61 to P66, respectively.

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 pipe temperature detection element 6 corresponds to a temperature detection means, the inverter IC circuit 33 and the DC power supply generation section 23 correspond to a voltage input means, and the reference voltage generation circuit 26 and the ``A''i setting circuit 27 correspond to , to the set temperature storage means (for the purpose), and the setting circuit 27 is set to the 5 field (for the surface temperature switching means).
The comparison circuit 28 corresponds to the comparison means, the output circuit 29n serves as the m selection output means, and the four-way switching valve 2 corresponds to the cycle g) switching means. The LSI 24 corresponds to frequency 'l' Jl separate means and 'use determining means +l'.

Next, the operation from the start of the heating operation to the 1'I'r'f operation will be explained based on FIGS. 2 to 5.

Let the discharge refrigerant humidity of lf compression +3:1 be Td, the suction refrigerant temperature of compressor 1 be Ts, the discharge pressure of aEM machine 1 be Pd, the suction pressure of compressor 1 be Ps, If the refrigerant temperature is n (where 1 (n (in relation to K, where K is the adiabatic compression index), then the discharge refrigerant humidity Td is expressed by the following formula (%). Therefore, when the outdoor heat exchanger 5 is not frosted, the suction refrigerant temperature Ts is In addition, the discharge refrigerant humidity Td is also high.

As the outside air decreases and frost formation improves, the suction refrigerant temperature Ts decreases and the discharge refrigerant humidity Td also decreases. The pipe temperature detection element 6 in the present invention is installed in the inlet pipe of the indoor MLJ heat exchanger 3 and detects the temperature of the part through which the high temperature and high pressure superheated region refrigerant gas discharged from the pressure #J machine 1 flows. The first temperature is a temperature lower than that of the discharged gas by a predetermined temperature due to heat loss in internal and external connecting pipes, etc.

Therefore, as shown in FIG. 4, when the outdoor heat exchanger 5 is not frosted, the suction refrigerant temperature of the compressor 1 is Ts.

The temperature t of the inlet pipes of the indoor heat exchanger 3 is both high, and gradually decreases as frosting progresses, and when frosting occurs which significantly reduces the heating capacity, the temperature t of the inlet pipe of the indoor heat exchanger 3 (m1) The degree t decreases at the end. In other words, if the inlet pipe temperature t becomes less than the set gag humidity t1, the heating capacity decreases,
Since young 111 is progressing, it is necessary to defrost it.

In addition, the capacity of the compressor 1 is different between 50 Hz and 60 Hz in terms of the power supply frequency, and the high pressure and discharge humidity of the outdoor heat exchanger 5 at 11↑ are also different.

That is, the inlet pipe temperature t of the indoor heat exchanger 3 is generally different between 50 Hz and 60 Hz, and the set pipe temperature t
If defrost determination is not performed by switching 1 between 50 Hz and 60 Hz, appropriate defrost detection cannot be performed depending on the power supply frequency, for example at 60 Hz, and the heating capacity cannot be fully demonstrated.

In this way, since the inlet pipe temperature t of the indoor heat exchanger 3 is the temperature of the refrigerant gas in the superheated region, it is not easily affected by the air volume of the indoor blower 7, and the inlet pipe temperature t of the indoor heat exchanger 3 is Appropriate defrosting operation judgment can be made at both 50 Hz and 60 Hz.

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

Here, for convenience of explanation, it is assumed that during the heating operation, the compressor, the four-way switching valve, the outdoor blower, and the relay elements R1 to R4 of the indoor blower operated at "low speed" are operating.

That is, in step 1 of Fig. 5, the power supply frequency is 60
60 Hz in step 2.
If so, set the boat P21 to Hi, and if it is 50 Hz, set the boat P21 to open. Specifically, the waveform signal from the inverter IC circuit 33 in FIG.
The frequency 'I'll discrimination means in 24 makes the determination, and the LSI
If the frequency is 60Hz, set the boat P21 on the output side of 24 to Hl, raise the base j% voltage created by the partial pressure of resistors 101 and 102, and set the set pipe temperature t1 to 50H of the power frequency.
It changes depending on z/60Hz.

After that, heating operation is started in step 3, the pipe temperature t is read by the pipe humidity detection element 6, and the process moves to i (step 4) and step 5, where the pipe humidity t is set to the same setting as that set in steps 1 and 2. It is determined whether the pipe temperature is lower than t1. Specifically, the comparison circuit 2B in FIG. 3 makes the determination.

When the conditions of step 5 are satisfied, the process moves to step 6 and defrosting operation is started. That is, each of the relay elements R1, R2, R3, and R4 of the output circuit 29 shown in FIG. , the indoor air blower vA7 and the outdoor air blower 8 are stopped, and defrosting is performed in the cooling cycle.

Since the content of this defrosting operation is conventionally well known, detailed explanation will be omitted. Further, the restoration of the heating operation can be carried out by any suitable means as is well known in the art.

In addition, in the wood example, the defrosting operation was performed by switching from the heating cycle to the cooling cycle.
For example, it goes without saying that a configuration may be adopted in which a separately stored refrigerant is flowed to the outdoor heat exchanger while the heating cycle is maintained, or a configuration in which frost is melted using a separate heat source. Also, compressor 1 is operated continuously when switching to defrosting operation, and the heating α rotation speed is set])'! It may be made to temporarily stop at 11fj.

Furthermore, the output status of the boat P21 according to the power frequency may be set to "Hl" when the frequency is 50 Hz, and the set value may be changed.

Effects of the Invention As stated above, according to the present invention, with the above-described configuration, the temperature of the refrigerant gas in the superheated region is detected at the indoor heat exchanger inlet V pipe, and the temperature is detected appropriately without being affected by the indoor air flow rate. Reliable defrosting operation can be performed with a single temperature detection point, hIk formation is very simple, and it can be determined whether the refrigerant has enough heat for heating using the indoor heat exchanger. Since defrosting can be carried out on the entrance side of the refrigerator, it is possible to reliably determine whether the heating capacity of the refrigerator is available before defrosting. Furthermore, even if the power supply frequency differs, the temperature is changed to the boundary value according to the frequency, so defrosting can be performed reliably and reliability and top quality are improved.

That is, the present invention uses 6 refrigerants in which young frost has completely occurred.
The refrigerant humidity on the inlet side is detected by focusing on the fact that there is no difference in temperature between the inlet and middle parts of the heat exchanger, and the inlet refrigerant temperature is significantly higher than the refrigerant temperature in the middle part when not frosted. As a result, the temperature change from no frost to 1τ2 can be largely controlled, and heating capacity close to the limit can be extracted by detecting the temperature at one point.

[Brief explanation of drawings]

Fig. 1 is a schematic 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 air conditioner refrigeration cycle showing an embodiment of the present invention. Fig. 4 is a characteristic diagram showing the relationship between the humidity of the refrigerant flowing into the indoor heat exchanger and the humidity of the refrigerant sucked into the compressor in the defrosting control device, and Fig. 5 is a circuit diagram of the defrosting control device. It is a flowchart which shows the operation content of a frost control device. 1... Compressor, 2... Four-way switching valve, 3...
...Indoor heat exchanger, 5.--Outdoor heat exchanger,
6... Piping temperature detection element (temperature detection means), 23...
...DC power generation section (clock input means), 24.
...LSI (,'l!IJ constant means), 26...
Reference voltage generation circuit (set temperature storage means'), 27...
...Defrost setting circuit (set temperature storage means), 2B...
... Ratio soft circuit (comparison means), 29 - Output circuit (selective output means), 30 ... Oscillation circuit, 31 ... Reset circuit, 33 ... Impark IC circuit (crochet input hand) crotch). Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
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Claims (1)

[Claims] A refrigeration cycle equipped with a compressor, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger is provided with cycle switching means for switching between a heating cycle and a defrosting cycle, and the cycle switching means is further configured to switch from a heating cycle to a defrosting cycle. The control device for switching to the indoor heat exchanger includes temperature detection means for detecting the temperature of a pipe connected to the refrigerant inlet side of the indoor heat exchanger, and set temperature storage means for storing a boundary value temperature for switching the heating cycle to the defrosting cycle. , a clock input means for inputting the power supply frequency; a frequency determination means for determining different frequencies of the power supply based on the output from the clock input means; and a frequency determination means for determining the set temperature storage means based on the output signal from the frequency determination means. A boundary value temperature switching means for switching the boundary value temperature, and a boundary value decrease signal from a comparison means for detecting and outputting that the temperature detected by the temperature detection means has fallen below the boundary value temperature stored in the set temperature storage means. , determination means for determining switching from the heating cycle to the defrosting cycle;
A defrosting control device for an air conditioner comprising a selection output means for controlling the refrigeration cycle from heating operation to defrosting operation according to the output of the determination means.