JPS62233631A - Control device for defrosting of air conditioner - Google Patents

Abstract

PURPOSE:To secure space heating operation and be able to carry out proper defrosting operation by temp. detection at one point by a method wherein frosting is found out by detecting the temp. of the refrigerant gas in an overheated region at the inlet piping of a indoor side heat exchanger and a set temp. is corrected by an indoor quantity and the frequency of electric power source when a specified time has elapsed after the start of space heating. CONSTITUTION:At the inlet piping of an indoor side heat exchanger in a refrigerating cycle, a detector for piping temp. is installed. Thereby, the existence of frosting is exactly detected. The frequency of a power source of a compressor is input into a frequency input means to judge whether the frequency is 50Hz or 60Hz and when 50Hz, a set temp. is lowered than that at 60Hz and in response to a detected signal from an air quantity change-over means in a room a set temp. change-over means is operated to lower the set temp. when an air quantity is larger. When the set temp. coincides with the detected temp. and a specified time has elapsed after the start of space heating, change-over from space heating operation to defrosting one is carried out by a selection output means.

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 the air conditioner that was obtained.

BACKGROUND ART Conventionally, as shown in Japanese Patent Publication TLDSS-32296, 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, Technologies have been developed to control heating and defrosting operations.

Problems to be Solved by the Invention However, such a conventional configuration requires a plurality of temperature detection elements (!:), resulting in a problem that the whiteness circuit becomes complicated.

Moreover, since this configuration detects the temperature of the gas-liquid mixed refrigerant while flowing through the heat exchanger, the temperature change between frost and non-frost is small, making it possible to make @frost determinations within a minute range. However, there is a problem that the detection accuracy is unstable.

In addition, in recent years, control devices are often configured by using microcomputers to perform complex signal processing, but the fact that there are many input signal sources (temperature detection elements) as in conventional technology makes it difficult to create programs. This is a source of negative effects, and there are limits to the simplification of programs. Furthermore, there is a problem that the humidity of the indoor heat exchanger is affected by the amount of indoor air circulating based on the operation of the indoor blower. This results in the inconvenience that the humidity in the heat exchanger increases and, even though defrosting operation is required for the outdoor heat exchanger, dehumidifying operation is not started.

Also, the difference in power supply frequency is 50HZ and 60H.
In the case of Z, the rotation speed of the compressor changes and the temperature of the indoor heat exchanger changes depending on the capacity of the refrigeration cycle.

For example, in the case of 80Hz, the rotation speed of the compressor is higher than that of 50Hz, and the capacity of the refrigeration cycle is greater, so the temperature of the indoor heat exchanger rises, and therefore, even though defrosting operation is required for the outdoor heat exchanger, defrosting is not possible. There was a problem that the frost operation did not start.

In view of the above-mentioned conventional problems, the present invention provides a defrosting control device whose configuration can be simplified without impairing the advantages of the conventional technology.

Means for Solving the Problems In order to solve the above problems, the present invention, as shown in FIG. a time measuring means for measuring time, a set time storage means for storing a preset time, and a match between the time detected by the time measuring element and the time set in the set time storage means. a temperature detection means for detecting the temperature of a pipe connected to the refrigerant inlet side of the indoor heat exchanger; and a setting storing a boundary value temperature for switching a heating cycle to a defrosting cycle. A temperature storage means, a frequency input means for inputting the power supply frequency, and the frequency & is 50.
A frequency determining means for determining whether the temperature is HZ or 60Hz, an air volume switching means for switching the air volume, a set temperature switching means for switching the set temperature based on each air volume and the output of the frequency determining means, and the temperature detected by the temperature detecting means is the set temperature. a second comparison means that detects and outputs a temperature drop below the boundary value stored in the storage means; a set time elapsed signal from the first comparison means; and a boundary value drop signal from the second comparison means; A determination means for determining switching from a heating cycle to a defrosting cycle, and a determination means for controlling the refrigeration cycle according to the output of the fIj determining means. Snoring?1. , 1 listen to the music 1z to the mr, and it is composed of 4 rare furnace output means.

Effect: With this configuration, the heating operation is ensured until a predetermined time has elapsed from the start of the heating operation, and after the elapse of the predetermined time, the defrosting operation is controlled based on the temperature detected by 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 one embodiment of the present invention. In the same figure, the refrigeration cycle includes compressor 1
, a four-way switching valve 2, an indoor heat exchanger 3, a rice 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 (condenser) during heating. In this case, during cooling 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.

Furthermore, the outdoor unit A is constituted by the compressor 1, the four-way switching valve 2, the pressure reducer 4, the outdoor heat exchanger 5, and the outdoor blower 8. In addition, the indoor heat exchanger 3
and an operation control unit (Fig. 3C) having a microcomputer (hereinafter referred to as microcomputer) programmed with the indoor blower 7, a pipe humidity detection element 6, a timer function, a temperature control function, etc. is an indoor unit)B
IC is installed. Here, the pipe temperature detection element 6 is
It is installed at a location away from the wind circuit that is not affected by the air blown by the indoor blower 7. Alternatively, the location may be near the indoor unit B.

FIG. 3 is a diagram showing an operation control section and a remote control section. The operation control unit C steps down the voltage supplied from the AC power supply 18 using the transformer 17, converts it into rectification using the diode glitch in the DC power supply generation unit 16, and controls the microcomputer 22 (hereinafter referred to as microcomputer) using the regulator IC. We are making the DC power supply to operate it. Microcomputer 2
2, the reset circuit 23 is connected to the PO port, and the transmitting circuit 2 is connected to the PO port.
6 is connected to the p1p2 port. A scan signal is output from the P7 and PB ports, and the operating switch air volume switching unit 24 and room temperature setting unit 25 switches are set to 0N.
By inputting various scan signals to the P3, P4, and P5 ports by the 10FF, predetermined control is performed. P1
A signal to operate the relay that drives the compressor 1 is output from port 1, a signal to operate the relay that drives the four-way valve 2 is output from the P12 boat, and a signal that operates the relay that drives the outdoor blower 8 is output from the P13 port. A signal is issued, and a signal for operating a relay that drives the indoor blower 7 is issued from ports P14 to P16. P17-P2
From the 0 boat, a signal is sent to the D/A converter 19 to generate a reference voltage for comparing the input from the suction sensor 7 with the room temperature, and a comparator that compares the reference voltage with the input of the suction sensor 7 is output. The output of the regulator 15 is input to the P21 boat. The microcomputer 22i receives the input from the room temperature setting section 25 of the remote control section, compares it with the input from the P21 boat, and performs 0N10FF control of the compressor 1. As the air volume switches from Hi to Me to Lo, P22 to P
A Hi signal is output from the output port 24, and the reference voltage is switched according to the temperature stored in the set temperature storage means 8 by the resistor 9.10. The reference voltage and the signal from the temperature detection means 6 are compared by a comparator 27, which is a second comparison means, and P
26. The full wave rectification is taken out from the diode bridge of the DC power source 16 and is input to the board 10 where it is converted into a tarok signal by the inverter 21. When the tarok signal is received and the 50/60 Hz determination means inside the microcomputer determines that the frequency is 60 Hz, a Hi output is output from the P25 boat, and the set value of the set temperature storage means is switched.

Comparing the configuration of FIG. 3 with the configuration of FIG. 1, the pipe temperature detection element 6 is used as the temperature detection means in FIG. The storage means includes the air volume switching switch 24 in the remote control section, the impark 21 as the frequency input means, and the resistor 11.1 as the set temperature switching means.
3.14, the 50/80 determination means, the setting time storage means, the first comparison means, the time measurement means, the determination means, and the selection output means correspond to the microcomputer 22.

Next, the operation from the start of heating operation to defrosting operation will be explained.

The discharge refrigerant temperature of the compressor 1 is Td, the suction refrigerant temperature of the compressor 1 is Ts, and the discharge pressure of the compressor 1 is Pd.

If the suction pressure of the compressor 1 is Pg and the l-rope index is n (where 1 (n (k), where k is the adiabatic compression index), then the discharge refrigerant temperature Td is expressed by the following formula. .

Therefore, when the outdoor heat exchanger 5 is not frosted, the suction refrigerant temperature Ts is high and the discharge refrigerant humidity Td is also high. Then, as the outside air drops and the frost grows, the suction refrigerant temperature Tg
decreases, and the discharge refrigerant temperature Td also decreases. The pipe temperature detection element 6 in the present invention is installed in the inlet pipe of the indoor heat exchanger 3, and detects the temperature of the part through which the high-temperature, high-pressure superheated refrigerant gas discharged from the compressor 1 flows. 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 Ts of the compressor 1 and the indoor 11tlJ inlet pipe temperature of the heat exchanger 3 are both high, and gradually increase as the frost progresses. When the indoor heat exchanger 30 inlet piping temperature (temperature) drops dramatically, the temperature of the indoor heat exchanger 30 inlet piping drops significantly. That is, if the inlet pipe temperature t becomes lower than the set pipe temperature tj (60 Hz air volume Lo), the heating capacity decreases, and since frost formation has progressed, it is necessary to defrost.

In addition, since this inlet pipe temperature is slightly affected by the air volume, as shown in Fig. 4, the air volume Lo (weak wind) and the air volume M
e (medium wind), air volume Hi (strong wind), set pipe temperature to tl
, [2, by changing t3 (for 60Hz),
Frost formation can be detected more accurately.

Furthermore, since the rotational speed of the compressor 1 is approximately a value compared to the power supply frequencies of 50 Hz and 60 Hz, the high pressure of the refrigeration cycle is higher when the frequency is 60 Hz. Therefore, the fourth
The inlet pipe temperature of the indoor heat exchanger shown in the figure is, if the solid line section t is 60 Hz, the broken line section t is 50 Hz, and if the defrosting start is fixed only at tl (air volume Lo), if it is 50 Hz, frost formation will occur. Before the amount of heat is low, the temperature reaches A11, and the heating efficiency deteriorates. Therefore, in the case of 50 Hz, the optimal defrosting operation can be ensured by setting the starting temperature of 'A1 for subtracting the inlet pipe temperature of the indoor heat exchanger to t,'.

Based on the above explanation, the control circuit shown in FIG. 3 performs the control of the contents of the flowchart shown in FIG. 50Hz or 60
Hz, if it is 60Hz, output P25 boat H
i and increase the piping temperature set value (step 4). Then, the microcomputer 22 sets a timer count for a predetermined time T (step 5). This timer count set is for ensuring heating operation for 7 hours (for example, 1 hour) from the start of heating operation, and one way is to forcibly continue heating for 1 hour, for example.

And once the timer count is set, step 6
It is determined that one hour has passed. Heating operation continues until one hour has passed.

Then, after 7 hours have passed, the air volume is determined.

If the wind volume is Lo (weak wind), the output of the P22 boat is set to H.
Step 7.8) If the air volume is Me (medium wind), set the P23 port output to Hi Step 9.10)
, in other cases (air volume Hi, strong wind), set the P29 port output to Hi (step 11).

In this way, using resistors 11 to 14, the set pipe temperature determined by the voltage formed by the partial pressure of resistor 9 and 10 in FIG.
By changing the set piping temperature, the power frequency can be increased to 50Hz.
, it is possible to change the set piping temperature in the case of 60Hz, and to change it depending on the air volume.

If the inlet pipe temperature is lower than t corresponding to each power frequency and each air volume, the comparator 27 will indicate Hi.
The specific output is output, and the microcomputer 22 receives the confirmation from the P26 boat (step 13), and defrosting operation is started.

(Step 14) That is, the P11 to P16 boat outputs are changed, the four-way switching valve 2 is switched, and if necessary, before that, the compressor 1 is stopped for a certain period of time, and the indoor blower A and the outdoor blower 8 are stopped. Defrost is then 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 this embodiment, the defrosting operation is 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 the heating cycle is maintained and a separately stored refrigerant is flowed to the outdoor heat exchanger, or a configuration in which a separate heat source is used to melt the frost. Further, the compressor 1 may be operated continuously when switching to defrosting operation, and may be temporarily stopped before returning to heating operation.

Effects of the Invention As described above, according to the present invention, with the above-described configuration, the temperature of the refrigerant gas in the superheated region can be detected at a single indoor heat exchange detection point, and the configuration is very simple. Since it is possible to determine whether or not there is a sufficient amount of heat for heating at the inlet side of the indoor heat exchanger, defrosting can be performed by reliably determining the presence or absence of actual heating capacity. That is,
In the present invention, there is no difference in the temperature of the refrigerant at the inlet part and the middle part of the heat exchanger when frost has completely formed, and the inlet refrigerant temperature is significantly higher than the refrigerant temperature in the middle part when no frost has formed. By paying attention to this point and detecting the refrigerant temperature on the inlet side, it is possible to significantly change the temperature from non-frosting to frosting, and it is possible to draw out the heating capacity close to the limit by detecting the hot water temperature at one point.

Furthermore, since the present invention does not detect frost formation until a certain period of time has elapsed from the start of heating, the heating capacity is ensured for that certain period of time, and comfort is not impaired.

[Brief explanation of drawings]

Fig. 1 is a block diagram expressing the defrosting control device of the present invention as a function realizing means, Fig. 2 is an embodiment of the present invention. A characteristic diagram showing the relationship between refrigerant temperature and compressor suction refrigerant temperature,
FIG. 5 is a flowchart showing the operation details of the defrosting control device. 1... Compressor, 2... Four-way switching valve, 3...
Old...Indoor heat exchanger, 5...Outdoor heat exchanger, 6...Piping temperature detection element, 9.1o...
...Set temperature memory resistance, 11.1 and 13.14...
... Set temperature switching resistor, 21 ... Power supply frequency input means, 22. River... Microcomputer, 27.
... Compare Lake-0 Name of agent Patent attorney Toshio Nakao and 1 other person Figure 1 Figure 4 Time

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. A control device configured to switch the control device to a time measuring means for measuring the time from the start of operation of the compressor, a set time storage means for storing a preset time, and a time detected by the time measuring means and the setting. a first comparison means for detecting and outputting the coincidence of times set in the time storage means; a temperature detection means for detecting the temperature of a pipe connected to the refrigerant inlet side of the indoor heat exchanger; A set temperature storage means for storing a boundary value temperature for switching to a defrosting cycle, a frequency input means for inputting a power supply frequency, a frequency determination means for determining whether the frequency is 50Hz or 60Hz, an air volume switching means for switching an air volume, and each air volume. and a set temperature switching means for switching the set temperature based on the output of the frequency determining means, and a second set temperature switching 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. a comparison means for determining switching from a heating cycle to a defrosting cycle based on a set time elapsed signal from the first comparison means and a boundary value drop signal from the second comparison means; 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.