JPS63131943A - Defrosting controller of air conditioner - Google Patents

Abstract

PURPOSE:To secure the space heating capacity for a predetermined period of time and to prevent the defrosting operation from being erroneously started by changing over the mode of operation from a space heating cycle to a defrosting cycle by a set time elapsed signal and a interface value lowering signal. CONSTITUTION:When a normal space heating operation is started, a power supply frequency is inputted and if the frequency is 60 Hz, the output of a port P25 is set to a high value, and a pipeline temperature set value is increased. The time count of a predetermined time T1 is counted by a microcomputer 22, and a space heating operation is continued until the time T1 passes. When the time T1 has passed, the timer count of a predetermined time T2 is set by the microcomputer 22. Then, the air flow rate is judged when it is judged to be weak, the output of a port P22 is set to a high value. When it is medium, the output of a port P23 is set to a high value. When it is strong, the output of a port P24 is set to a high value. The pipeline temperature is read by a pipeline temperature detecting element 6. If the pipeline temperature is lower than the set pipeline temperature corresponding to each power source frequency and air flow rate, a high output is generated from a comparator 27. Until a time T2 passes, the space heating operation is continued, and the defrosting operation is started.

Description

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

BACKGROUND ART Conventionally, as shown in Japanese Patent Publication No. 5B-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, which naturally causes the problem of complicating the circuit. Furthermore, 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, and frost formation must be determined within a minute range. However, there is a problem that the detection accuracy is unstable.

In recent years, control devices are often constructed 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 harmful effects, and there are limits to the simplification of the program.

Furthermore, there is a problem in that the temperature of the indoor heat exchanger is also affected by the amount of indoor air circulation based on the operation of the indoor blower.
For example, if the amount of indoor air circulating to the indoor heat exchanger is small, the temperature of the indoor heat exchanger will rise accordingly, and even though defrosting operation is required for the outdoor heat exchanger, defrosting operation is not performed. This causes the inconvenience of not starting.

A difference occurs and the temperature of the indoor heat exchanger changes. For example 60H
In case of 50 H2, the temperature of the indoor heat exchanger rises because the compressor rotation speed is higher and the capacity of the refrigeration cycle is larger than in the case of H2. There was a problem in that the defrosting operation did not start immediately.

5. In view of the above-mentioned conventional problems, the present invention provides a defrosting control device that can be simplified in configuration without sacrificing the advantages of the prior art.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention, as shown in FIG. a first time measuring means for measuring the time from , a first set time storage means for storing a preset time, and a time detected by the first time measuring means and the first 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 during heating operation; a set temperature storage means that stores a boundary value temperature for switching the cycle to a defrosting cycle; and a second temperature storage means that measures the time when the temperature detected by the temperature detection means falls below the boundary value temperature stored in the set temperature storage means. a second set time storage means, and a second set time storage means that stores the time detected by the second time measurement means and the second set time storage means; a second comparison means for detecting and outputting the coincidence of the set times; a frequency input means for inputting the power supply frequency;
a frequency determining means for determining whether the temperature is 0 H2 or 60 H2; 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; a third comparison means for detecting and outputting a decrease in temperature below the boundary value temperature stored by the set temperature storage means; a set time elapsed signal from the first and second comparison means; and a boundary signal from the third comparison means. It is composed of a determining means for determining switching from a heating cycle to a defrosting cycle based on a value decrease signal, and a selection output means for controlling the refrigeration cycle from a heating operation to a defrosting operation in accordance with the output of the determining means. be.

Effect: With this configuration, heating operation is ensured until a predetermined time has elapsed from the start of heating operation, and at that predetermined time 7 hours.

After a certain period of time has elapsed, the defrosting operation is controlled by the set temperature storage means that stores the boundary value temperature that changes according to the air volume and 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 7. 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 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 (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, 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, a microcomputer in which the indoor heat exchanger 3 and the indoor blower 7, a pipe temperature detection element 6, a timer function, a temperature adjustment function, etc. are programmed, is also provided.
2 (hereinafter abbreviated as microcomputer)
FIG. 3C) is installed in the 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 located near indoor unit 1-B.

FIG. 3 is a diagram showing the operation control section C and the control operation section. The operation control unit C steps down the voltage supplied from the AC power supply 18 with a transformer 17, converts it into full-wave rectification with a diode bridge in the DC power generation unit 16, and creates a DC power supply that operates the microcomputer 22 with a regulator IC. There is. In the microcomputer 22, a reset circuit 23 is connected to the P□ port, and an oscillation circuit 26 is connected to the Pl, P2 ports. P7
．． A scan signal is output from the P8 port, and the operation switch air volume switching unit 24 and room temperature setting unit 25 (
7) ONloFFKJ: Su, P3, P4, P5
Predetermined control is performed by inputting various scan signals to the port 9page-7. A signal to operate the relay that drives the compressor 1 is sent from the pH port, and the four-way switching valve 2 is sent from the P12 boat.
The P13 boat outputs a signal to operate the relay that drives the outdoor blower 8, and the P14 to P16 ports output a signal to operate the relay that drives the indoor blower 7. Served. P, 17-P 20' From the boat, suction sensor 29
The reference voltage for comparing the input from the D/A and the room temperature is
A signal generated by the converter 19 is output, and its reference voltage and
The output of the comparator 15 that compares the input of the suction sensor 29 is input to the P21 port. The microcomputer 22 receives the input from the room temperature setting section 25 of the control operation section, compares it with the input from the P21 port, and performs ON/OFF control of the compressor 1. As the air volume switches from Hi to Me to Lo, P2
A Hi-multiply signal is output from the output ports 2 to P24, and the reference voltage is switched according to the temperature stored in the resistor 9.degree. 10 of the set temperature storage means 28. Its reference voltage and temperature detection means 3
0 signal is compared by the comparator 27 corresponding to the 10th H-73 comparison means, and the P26
is input. The power supply frequency signal is sent to the D% power generation section 16.
The clock signal is converted into a clock signal by the inverter 21 and inputted to the P10 port. Upon receiving the tarok signal, the microcomputer 22
When the internal 50/60H2IJ constant means determines that the temperature is 60H2, a Hi high output is output from the P25 port, 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, that is, the temperature detection means 30 is the temperature detection means of FIG. 1, and the comparator 27 is the third comparison means.
The resistor 9.10 serves as a set temperature storage means, the air volume selector switch 24 on the control operation section serves as an air volume setting means, and the impark 2
1 is a frequency input means, and resistors 11, 12, 13, and 14 are
The microcomputer 22 includes the first and second set time storage means, the first and second time measurement means, the 50/60H2 determination means, the set temperature storage means, and the first set temperature storage means shown in FIG.
, second and third comparison means, determination means, and selection output means.

1 1 l+-; 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, the discharge pressure of the compressor 1 is Pd, the suction pressure of the compressor 1 is Ps, and PolJ1. Let the rope index be n (however,
1 < n < k, where k is an adiabatic compression index), the discharge refrigerant temperature Td is expressed by the following equation.

Pd n Td=Ts·(Ps) Therefore, when the outdoor heat exchanger 5 is not frosted, the suction refrigerant temperature Ts is high, and each discharge refrigerant temperature Td is also high. Then, as the outside air drops and frost grows, the suction refrigerant temperature Ts
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 determined as a temperature lower than that of the discharged gas by a predetermined temperature due to heat loss in internal and external connecting piping, etc. Therefore, as shown in FIG. 4, when the outdoor heat exchanger 5 is not frosted, both the suction refrigerant temperature Ts of the compressor 1 and the indoor heat exchanger 30 input pipe temperature t are high, and frosting progresses. As the temperature increases, the temperature t of the inlet pipe of the indoor heat exchanger 3 gradually decreases, and when frost formation occurs which significantly reduces the heating capacity, the temperature t of the inlet pipe of the indoor heat exchanger 3 decreases extremely. That is, if the inlet pipe temperature t becomes equal to or lower than the set pipe temperature t 1 (60H2 air volume Lo), the heating capacity decreases, and since frost formation has progressed, it is necessary to defrost.

Also, since this inlet pipe temperature is slightly affected by the air volume, as shown in Figure 4, the air volume LO (weak wind) and the air volume M
'e (medium wind), air volume Hi (strong wind) can be known. Furthermore, the rotation speed of the compressor 1 is set to a power frequency of 50Hz and 60H.
Since the value is almost proportional to 2, the high pressure of the refrigeration cycle is high at 60 Hz. Therefore, the inlet pipe temperature of the indoor heat exchanger shown in Fig. 4 is, if the solid line section t is 60H2, the broken line section t is 50H2, and if the defrosting start is fixed only at (21 (air volume 131・-7 Lo)), it is 50H2. In this case, defrosting will begin before there is much frost and heating efficiency will deteriorate.

Therefore, in the case of 50H2, by setting the defrosting start temperature of the inlet pipe temperature of the indoor heat exchanger to 117, optimal defrosting operation is ensured.

Based on the above explanation, the control circuit shown in FIG. 3 controls the contents of the flowchart shown in FIG. 7.

If it is 60H2, set the P25 boat to output Hi and increase the piping temperature set value (Step 4). Then, the microcomputer 22 sets the number of units for a predetermined period of time T1 (step 5). For example, one method is to forcibly continue heating for T1 hours.

When the timer is set, it is determined in step 6 whether the time T1 has elapsed. The heating operation is continued until the time T1 has elapsed (see FIG. 5).

Then, when the time T1 has elapsed, the microcomputer 2
At step 2, the count for a predetermined time T2 is set. In this second timer actuator set, the pipe temperature t is the set pipe temperature (t by the air volume switching means, s t 2・13).
Since the time T2 (for example, 1 minute) in which the temperature is continuously lower than (See Figure 6). Then, when this timer count is set, the air volume is determined. If the wind volume is L (weak wind), set the output of the P22 boat to Hi (step 8.9), and if the wind volume is Me (medium wind),
Set the P23 port output to Hi (step 10.11)
In other cases (air volume H1 strong wind), the P24 port output is set to Hi (step 12). In this way, using resistors 11 to 14, set pipe temperature determined by the voltage formed by the partial pressure of resistor 9 and 10 in Figure 3,
The difference between 0H2 and 15t-.

7 is possible by changing the set piping temperature by changing the air volume.

Once the set pipe temperature is set, the pipe temperature t is read by the pipe temperature detection element 6 in step 13.

Then, if the inlet pipe temperature t is lower than the set pipe temperature tx corresponding to each power frequency and each air volume (step 14), the comparator 27 outputs H1.

When the condition of step 14 is satisfied, step 15
It is determined that two hours have passed. The heating operation is continued until 12 hours have elapsed, and if the inlet pipe temperature t is greater than the set pipe temperature tx before 12 hours have elapsed, the process returns to step 7 and the second timer counter is reset.

Then, when the conditions of step 15 are satisfied, step 16
The defrosting operation starts.

That is, the P11 to P16 port outputs are changed, the four-way switching valve 2 is switched, and if necessary, the compressor 1 is stopped for a certain period of time, and the indoor blower 7 and the outdoor blower 8 are stopped.

Then, defrost 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 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 frost is melted using a side heat source. 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, the temperature of the superheated refrigerant gas can be controlled by indoor heat exchange with the above-described configuration, and the configuration is very simple, and the sweet refrigerant can be used for heating. Since it can be determined at the inlet side of the indoor heat exchanger whether or not there is enough heat to perform can.

In other words, 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 when no frost has formed, the inlet refrigerant temperature is higher than the refrigerant temperature in the middle part. By focusing on extremely high points and detecting the refrigerant temperature on the inlet side, it is possible to detect large temperature changes from unfrosted to frosted, and it is possible to draw out heating capacity close to the limit by detecting the 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.

Furthermore, since the indoor heat exchanger's pipe temperature does not continuously fall below the set temperature, the defrosting operation is not started, so the pipe temperature may be detected to be lower than the actual temperature due to noise, etc.
Defrosting operation will not be started by mistake.

[Brief explanation of the drawing]

Fig. 1 is a block diagram expressing the defrosting control device of the present invention as a function realizing means, Fig. 2 is a refrigeration cycle diagram of an air conditioner showing an example of implementation 18.,-1 of the present invention, and Fig. 3 is Figure 4 is a circuit diagram of the defrosting control device in the air conditioner, and Figure 5 is a characteristic diagram showing the relationship between the temperature of the refrigerant flowing into the indoor heat exchanger and the temperature of the refrigerant sucked into the compressor in the defrosting control device. A relationship diagram between operating time and pipe temperature showing that the heating operation continues for a certain period of time T1 from the start of heating, and FIG. 6 shows that the defrosting operation will not start until a predetermined period of time T2 in which the temperature falls below the set temperature has elapsed. Relationship diagram between operating time and pipe temperature, No. 7
The figure is a flowchart showing the operation details of the defrosting control device. 1... Compressor, 2... Four-way switching valve, 3
... Indoor heat exchanger, 5 ... Outdoor heat exchanger, 6 ... Piping temperature detection element, 9.10.
...Setting temperature memory resistance, 12.13.14...
... Set temperature switching resistor, 22 ... Microcomputer, 27. River ... Name of Compare Lake agent.
Patent attorney Toshio Nakao and one other person Figure 1 I-Yiyangmyo ticket? -Cutting blade W horizontal square a-! Inner thermophilic drinker 4-11pen mu cup A-1 room dato unit) B-1 ship unit Fig. 2 0 FujiP4-

Claims (1)

[Claims] A refrigeration cycle equipped with a compressor, an indoor heat exchanger, a pressure reducer, 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 switches from the heating cycle to the defrosting cycle. a first time measuring means having a control device for switching the control device to a cycle, a first time measuring means for measuring the time from the start of heating operation of the compressor; and a first set time memory storing a preset time. means, first comparing means for detecting and outputting a match between the time detected by the first time measuring means and the time set in the first set time storage means, and the indoor heat exchanger during heating operation. a temperature detection means for detecting the temperature of a pipe connected to the refrigerant inlet side of the container; a set temperature storage means for storing a boundary value temperature for switching a heating cycle to a defrosting cycle; and a temperature detected by the temperature detection means; a second time measuring means for measuring the time when the temperature drops below a certain set temperature value stored in the set temperature storage means; a second set time storing means for storing a preset time; a second comparing means for detecting and outputting a match between the time detected by the time measuring means and the time set in the second set time storage means; a frequency input means for inputting a power supply frequency; a frequency determining means for determining whether the temperature is 60 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 power frequency determining means; A third device detects and outputs that the temperature has fallen below the boundary value stored in the set temperature storage means.
, the switching from the heating cycle to the defrosting cycle is determined based on the first and second set time elapsed signals from the first and second comparing means and the boundary value drop signal from the third comparing means. A defrosting control device for an air conditioner, the defrosting control device for an air conditioner comprising: a determining means for determining, and a selection output means for controlling the refrigeration cycle from heating operation to defrosting operation according to the output of the determining means.