JPS61268938A - Defrosting operation control unit of air conditioner - Google Patents

Abstract

PURPOSE:To make it possible to operate the air conditioner at an appropriate frosting operation constantly from the viewpoints of confortableness and operational efficiency by starting the defrosting operation when the temperature detected in an outdoor heat exchanger detecting portion and an external air humidity detecting portion is zero degree or less and the humidity is more than a predetermined value and a counted value obtained by counting means reaches a predetermined value. CONSTITUTION:Output signals emitted from an outdoor heat exchanger temperature detecting portion 1 and external air humidity detecting portion 2 are input in an A-D converter 13 via amplifiers 11 and 12. A micro-counter 10 transmits a signal to the A-D converter 13 and reads in external humidity data from the external humidity detector 2 and also outdoor heat exchanger temperature data. When a read in external humidity data is 60% RH or more and the temperature of the outdoor heat exchanger is 0 deg.C or less, counting is carried out at a predetermined speed with respect to the temperature and humidity at that time. When the counted value reaches a predetermined value, a defrosting starting signal is delivered to an output part 14, and the output part 14 outputs a signal to start the defrosting operation to the air conditioner.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an air-source heat pump type air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger are connected in sequence. This relates to machine defrosting and operation control equipment.

BACKGROUND ART Air conditioners with a heat pump type refrigeration cycle that can perform not only cooling operation but also heating operation are increasingly being used.

By the way, in the heating operation described above, since the refrigerant evaporates in the outdoor heat exchanger, moisture in the air condenses and adheres to the heat exchanger.

When this moisture freezes due to a drop in outside temperature, it turns into frost and impedes heat exchange, so it is necessary to defrost it as appropriate.

Refrigeration cycles for removing frost on the outdoor heat exchanger include a reverse cycle type, a hot gas bypass cycle type, and a heating defrost cycle type.

In the reverse cycle type, when switching from heating operation to defrosting operation, the four-way valve is switched to change the direction of refrigerant flow.
Reverse high pressure and low pressure. In this way, high-pressure gas flows through the outdoor heat exchanger, and this heat melts the frost.

In the hot gas bypass cycle type, defrosting is performed while heating operation is performed. Turn on the solenoid valve to create a high-temperature, high-pressure gas bypass cycle to defrost.

In the heating defrost cycle type, an electric valve with a solenoid valve function is used as the flow control valve, and when defrosting, the valve is fully opened by the defrost signal, and the flow control valve does not function as a throttle function (expansion valve). Functions as a solenoid valve to move liquid refrigerant.

As mentioned above, there are various refrigeration cycles for defrosting.
All of them have some kind of frost detection means, and the defrosting operation is performed based on the signal from the frost detection means.

[Prior art and problems to be solved by the invention] Conventionally,
One method for detecting frost formation and starting a defrosting operation is to use a combination of the pipe temperature of the outdoor heat exchanger, the outside air temperature, and a timer. In this method, the piping temperature of the outdoor heat exchanger and the outside air temperature are detected, and frost formation is detected using a predetermined outside air versus outdoor heat exchanger temperature characteristic. After a predetermined period of time, if the temperature is higher than the set temperature, which changes depending on the outside temperature,
The heating operation continues and waits until the temperature drops below the set temperature.

In this method, defrosting is not performed within a certain period of time after the start of operation, and even if the outside air temperature is low and no frost has formed, if the temperature and time requirements are met, defrosting is performed. There is a problem in that it is difficult to drive, which is contrary to energy saving and also impairs comfort.

In addition, as recommended in Japanese Patent Application Laid-Open No. 59-46438, the start of defrosting operation is determined based on the outdoor heat exchanger piping temperature and outside air relative temperature. Some devices start defrosting operation when the temperature is below a certain value and the relative temperature is above a certain value. However, in this method, since the defrosting operation starts with the start of frost formation, it becomes a hunting operation in which heating operation and defrosting operation are repeated, which is difficult to implement.

Therefore, a method of starting defrosting operation after a certain period of time after the start of frost formation is considered, but since the speed of frost formation differs depending on the situation after the start of frost formation, this method always provides the optimum defrosting operation in terms of comfort and operational efficiency. Defrosting operation cannot be started due to the amount of frost.

[Means for solving problems]

In view of the above-mentioned conventional problems, the present invention aims to provide a defrosting operation control device that improves comfort and operational efficiency by sending a defrosting start signal to an air conditioner at an appropriate time. It is something.

The defrosting operation control device created for this purpose, as shown in FIG. 1 showing the basic configuration, includes an outdoor heat exchanger temperature detection section l that detects the temperature of the outdoor heat exchanger, and an outdoor heat exchanger temperature detection section l that detects the humidity of the outside air. an outside air humidity detection section 2, and a determination means 3 that determines that the temperature detected by the outdoor heat exchanger detection section 1 is below zero degrees and the humidity detected by the outside air humidity detection section 2 is above a predetermined value; When the determination means 3 determines that the temperature is below zero degrees and the temperature of the room is above a predetermined value,
A counting means 4 is provided for counting at a predetermined speed with respect to the detected temperature and detected humidity at this time, and the defrosting operation is started when the count value by the counting means reaches a predetermined value. It is characterized by

[For production]

Figure 2 shows the characteristics of outdoor heat exchanger temperature vs. operating time (1) until the amount of frost builds up, for example, 1 kg, for the outdoor heat exchanger of an air conditioner, and outside air humidity is also a variable. This is taken into account.

As can be seen from the figure, the lower the outdoor heat exchanger temperature and the higher the outside air humidity, the faster the rate of frost formation, so the time t until a constant amount of frost formation is reached is shorter. In other words, if the time required to reach a certain amount of frost is t, then t is expressed as a function of the outdoor heat exchanger temperature (TE) and the outside air relative humidity (HA).

t = F (TE s Ha ) In view of the above-mentioned phenomenon, the defrosting operation control device according to the present invention controls the ever-changing temperature of the outdoor heat exchanger and the temperature of the outside air when the frosting conditions are satisfied. The humidity is counted at a predetermined speed, and when the count value reaches the predetermined value, it is assumed that the amount of frost has reached the predetermined amount and defrosting operation is started, so defrosting is always performed in the optimal condition. It is now possible to start frost operation.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figure 3 shows a 1-chip microcomputer (μC0N) 1
1 is a block diagram showing an embodiment of the defrosting operation control device according to the present invention configured using 1 and 2.
are an outdoor heat exchanger temperature detection section and an outside air humidity detection section, respectively. The output signals of the rain detectors 1 and 2 are input to an analog-to-digital (A-D) converter 13 via amplification widths 11 and 12, respectively. A-D converter 13 is μCOM
Based on the sampling signal from 10, the input analog signal is converted to a digital signal and output, and this is
Add to each input of 0NIO.

μC0NIO is the arithmetic processing unit (ALU), ROM, RA
A-D
It controls the converter 13, inputs digital data from the A-D converter 13, uses the digital data to read out data that has been previously stored in the ROM, or makes decisions about the data under specific conditions. and performs logical operation processing based on these, and sends the result to the output unit 14.

The output unit 14 is composed of TTL, relay contacts, and the like, and sends out a defrost start signal and a defrost end signal to a control device of an air conditioner (not shown).

The operation of the above configuration will be explained with reference to the flow chart of the work performed by μC0NIO according to the program shown in FIG.

μC0NIO initializes in step S1 after starting, for example, by turning on the power, and then
A signal is sent to the converter 13, and in step S2 data regarding the outside air humidity is read from the outside air humidity detection section 2, and data regarding the outdoor heat exchanger temperature is also read in step S3. In S4, timer interrupt cycle data is retrieved by referring to the timer interrupt cycle data table in the ROM, and in the next step S5, this data is set in the timer register in μC0NIO, and the execution point of the timer interrupt routine is determined based on this data.

The timer interrupt cycle data table stored in the ROM is based on the outdoor heat exchanger temperature TE, which is calculated from the graph in Figure 2, which shows the time required for a certain amount of frost to form with respect to outdoor heat exchanger temperature and outdoor air humidity. , was created based on the graph in Figure 5 showing the outside air humidity and timer interrupt cycle.For example, the humidity is 60% RH or higher, 1% RH
The purpose can be achieved by creating a table for each temperature TE below 0°C and 1°C.

The timer interrupt routine is as shown in FIG. 4(b), and is executed at any time when the timer that set the data times out.
The main routine of a) is interrupted.

The first step S' of the subroutine is step S'1.
It is determined whether the outside air humidity read in step 2 is 60% RH or more, and if the determination is NO, the process returns to the original main routine. Then, if the determination is YES, in the second step S'2, it is determined whether the outdoor heat exchanger temperature read in step S3 is below 0°C, and if the determination is NO, the original main routine is resumed. Return to And the verdict is YES
In the third step S'3, it is determined whether the air conditioner is currently in defrosting operation, and if the determination is YES, the process returns to the main routine, and the process returns to N.

If so, the counter value is incremented by 1 in the next fourth step S'4, and the process returns to the main routine.

After the data is set in the timer register in step S5, the process proceeds to the next step s6, where it is determined whether the counter has overflowed or not. The capacity of this counter is determined according to the periodic data table and the characteristics of the air conditioner to which it is applied.

When the determination in step S6 is No, the process returns to step S2, and steps S2 to s6 are executed again, and this is repeated until the determination becomes YES. If the determination is YES, the process proceeds to step S7, where a defrosting start signal is sent to the output unit 14.

In response, the output unit 14 outputs a signal that causes the air conditioner to start its defrosting operation.

Subsequently, in step S8, the outdoor heat exchanger temperature Tt
In step S9, it is determined whether or not the read data for Ti has reached the defrosting end temperature.
It will be carried out at While the determination in step S9 is NO, steps 87 to S9 are repeated, and when the determination is YES, in the next step S10, a defrosting end signal is sent to the output unit 1.
4 and stop the defrosting operation of the air conditioner. Thereafter, the counter is reset in step Sll, and the process returns to step S2.

For example, assuming that the basic cycle of the μC0NIO timer interrupt is 43.6 μs, when data at point a in FIG. 5 is read, the cycle corresponding to the data is 1
0011s, the value on the timer interrupt cycle data table is set to 3, for example, and a timer interrupt is generated by counting three basic clocks. Therefore, when interrupting the subroutine approximately every 100 μs, if steps S'l and S'2 are YES and the determination in S'3 is NO, the counter will be incremented by 1, and the value of the counter will be The defrosting operation is started when the frost amount reaches a predetermined value, that is, when the frost amount reaches a predetermined amount.

In short, the counter is designed to count only when frost is progressing, at a speed that corresponds to the rate of progress of frost, so the amount of frost can be known from the counted value, so the counter When the amount of frost reaches a predetermined value, it is known that the amount of frosting has reached the amount at which defrosting should be started, and the defrosting operation can be started.

Note that in the above example, the counting speed of the counter is changed by changing the timer interrupt depending on the input data, but without using such an interrupt,
For example, this may be done by changing the number counted up by a counter in a predetermined range based on input data when a condition is satisfied.

Figure 6 shows the A-D converter 13 and μC0N in Figure 3.
FIG. 4 is a block diagram showing another embodiment of the defrosting operation control device according to the present invention configured by a discrete circuit instead of an IO, and the same parts as those in FIG. 3 are given the same reference numerals.

In the figure, 20a is a voltage-frequency (V-F) converter, which generates a pulse train with a frequency proportional to the voltage applied to its input, and sends it to an AND gate 20b. 20c
is a function generator which converts the humidity signal output from the amplifier 12 and the temperature signal output from the amplifier 11 into V-F.
The conversion is performed so as to match the input level of the converter 20a. The fact that the time t required to reach a certain amount of frost formation is short means that the converted frequency is high. In terms of the relationship with the input applied voltage, the lower the outdoor heat exchanger and the higher the outside air humidity, the higher the frequency.
The input applied voltage is also high. This can be illustrated as shown in FIG. 7. For example, the V-F converter 20a
/ If a device with a V function is used, the frequency at point a in Figure 7 is 10 KHz.

The point oscillates at 4KHz.

The comparator 20d compares the humidity signal output from the amplifier 12 with the set reference voltage corresponding to humidity 60% RH, and if the outside air humidity is lower than the set humidity, sends an L level, and if higher, sends an H level to the AND gate 20b. do.

In addition, this standard of 60% RH means that the outside air humidity is 60% R.
This setting was made because if it is lower than H, no growth will occur even if frost forms.

Similarly, the comparator 20e compares the humidity signal output from the amplifier 11 with the set reference voltage corresponding to 0°C,
If the outdoor heat exchanger temperature is higher than the set temperature, set the L level.
If it is low, an H level is sent to the AND gate 20b.

AND game) 20b is under conditions that allow frost formation,
That is, only when the outside air humidity is high and the outdoor heat exchanger temperature is low, the pulse waveform generated by the V-F converter 20a is sent as a clock to the counter 20f.

On the counter 20f, for example, 24 stage glue, nople, etc.
Using a binary counter, 224=16.
Output is produced by inputting 777,216 clock pulses.

For example, point a in Figure 7 (Tt = 7℃, 90%RH
), the iov input causes 10KHz oscillation, overflows at 0KHz, and point b (Ti = -s℃, 8
(at 0%RH), 4V input results in 4KHz oscillation, and overflow occurs at KHz.

As described above, when the count ends due to overflow, the next stage latch 20g is output, and a signal is sent to the output section 14, which sends a defrosting start signal to the air conditioner.

The comparator 20h compares the temperature signal output from the amplifier 11 with the set reference voltage corresponding to approximately 10°C, and when the outdoor heat exchanger temperature becomes higher than the defrosting end temperature, it outputs an H level and becomes lower. At the time, I put out L level.

The monomulti 20i detects the rising signal of the comparator 20h (positive edge) and generates a one-shot pulse. The power-on reset generating section 20j generates a one-shot pulse when the power is turned on. The OR gate 20 performs the OR of the two one-shot pulses, and resets the counter 2Of and the latch 20g. As a result, the air conditioner receives the defrosting end signal, ends the defrosting cycle, and returns to heating operation.

〔effect〕

As explained above, the defrosting operation control device according to the present invention counts the time until a certain amount of frost is formed in the refrigeration cycle device where frosting occurs, depending on the outdoor heat exchanger temperature and the outside air humidity. Since idle defrosting operation due to suspicious frost detection can be prevented, it is possible to improve comfort and driving effectiveness.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic configuration of the device according to the present invention, Fig. 2 is a graph showing the time required to reach a certain amount of frost with respect to outdoor heat exchanger temperature and outside air humidity, and Fig. 3 is a diagram showing the basic configuration of the device according to the present invention. 4 is a flowchart for explaining the operation of the device shown in FIG. 3, FIG. 5 is a characteristic graph used in the embodiment shown in FIG. 4, and FIG. 6 is a diagram showing the device according to the present invention. A block diagram showing another embodiment, and FIG. 7 are characteristic graphs used in the embodiment of FIG. 6. DESCRIPTION OF SYMBOLS 1... Outdoor heat exchanger temperature detection part, 2... Outdoor humidity detection part, 3... Judgment means, 4... Counting means. Patent applicant: Saginomiya Seisakusho Co., Ltd. Figure 5-To-B -6-4-202JL iTE
IQ -8-6-4-202: JL Exhibition IC) Procedural amendment (spontaneous) October 31, 1985 Mr. Michibu Uga, Public Prosecutor 1, Indication of the case 1985 Patent application No. 108373
No. 2, Name of the invention: Air conditioner defrosting operation control device 3, Name of the person making the amendment: Hanyu Patent applicant address: 5-5 Wakamiya, Nakano-ku, Tokyo Name: Saginomiya Seisakusho Co., Ltd. 4, Agent: 5 , Date of amendment order: Showa, Month, Day 6,
Number of inventions increased by amendment Contents of amendment (Japanese Patent Application No. 108373/1983) 1. The following statement is inserted between the 6th and 7th lines of page 2 of the specification. “[Prior art and problems to be solved by the invention]” 2
, the statement on page 3, line 17 of the same book is deleted. 3. Correct "relative temperature" to "relative humidity" in lines 14 and 16 of page 4 of the same book. 4. On page 4, line 18 of the same book, "due to the start of frost formation" is corrected as follows. "If the outside air relative humidity is lower than a certain value (if not, then again when heating operation is restarted after defrosting") 5. Correct rlkgJ to r500 gJ on page 6, line 7 of the same book.6. In the same book, page 6, line 10, "lower" is corrected to "higher." is 1 ms
Correct to J. 8. In the same book, page 11, line 18, "The period is 100" is corrected to "The count period is 200." 9. "Predetermined value..." in the same book, page 12, lines 5 and 6
...sometimes" is corrected as follows. "Assuming that the amount of frost has reached a predetermined amount, that is, 18,000 in this example," 10, Ibid.
Correct "according speed" in line 9 of page 2 to "according period". 11. In the same book, page 12, lines 15 to 17, "the counting speed...is being varied" is corrected as follows. ``The count period, that is, the timer interrupt period, is changed by making it correspond to changes in input data.'' 12. Correct ``number'' in line 19 of page 12 of the same book to ``predetermined value.'' 13. In the same book, page 13, line 17, ``the lower the temperature,'' is corrected to ``the higher the temperature.'' 14. Correct "10" in the first line of page 14 of the same book to r4.68J. 154th edition, page 14, line 2, "4" is corrected to r2.15J. 16. In the same book, page 14, line 12, "humidity" is corrected to "temperature." 17. [Outside air...
``Only when...'' is corrected as follows. "Only when the outside air humidity is 60% RH or more and the outdoor heat exchanger temperature is 0°C or less" The statement on page 15 of the 0 times a day book has been corrected as follows. ``For example, 24 stages of rimple on counter 20f.
Using a binary counter, 224=16.
An output is produced by inputting 777.216 clock pulses. For example, point a in Figure 7 (Tt = 5℃, 85%RH
), 4.68V input causes oscillation of 4.68KH2, overflow occurs at point b (TE = -5℃, 7
In the case of 5%RH (7)), 2.15V input results in oscillation of 2°15KHz, 12 - x 16,777.216 = 7.803 seconds #1
At 2.15 in the 30th minute, there was an overflow at ■2. As described above, when the count ends due to overflow, the next stage latch 20g is set and a signal is sent to the output section 14, and the output section 14 sends a defrosting start signal to the air conditioner. The comparator 20h is output from the amplifier 11.''19
Figures 2, 5 and 7 of the drawings are replaced with the attached drawings. Patent applicant: Saginomiya Seisakusho Co., Ltd. Figure 2-16-14-12-To-8-6-4-202;
i /L TE ('c) Hot spring TE ('C1

Claims (1)

[Claims] In an air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger are connected in sequence, an outdoor heat exchanger temperature detection section that detects the temperature of the outdoor heat exchanger and the humidity of the outside air are used. an outside air humidity detection unit that detects the temperature, a determination unit that determines that the temperature detected by the outdoor heat exchanger detection unit is below zero degrees, and the humidity detected by the outside air humidity detection unit is equal to or higher than a predetermined value; and a counting means for counting at a predetermined speed with respect to the detected temperature and the detected humidity at this time when the determining means determines that the temperature is below zero and the humidity is above a predetermined value, A defrosting operation control device characterized in that a defrosting operation is started when a count value by a counting means reaches a predetermined value.