JPS61211658A - Defrosting controller of heat pump type air conditioner - Google Patents

Abstract

PURPOSE:To excellently control a defrosting operation during a space heating mode operation and to reduce the accumulation of ice in an outdoor heat exchanger when the outside air temperature is lowered, by providing a flip-flop circuit for storing the time in which an output is emitted from a defrosting completion temperature detection circuit. CONSTITUTION:In a case where, upon restoration of the air conditioner from a defrosting operation to a space heating operation, the restoration is made by an output of a defrost chance timer 5 in a flip-flop circuit 3, it is stored by the defrost chance timer 5 until the restoration operation is carried out by a defrost completion temperature detection circuit 9 since then that the restoration has been carried out by the defrost chance timer 5, and the frequencies of oscillation circuits 1 and 2 are increased by outputs from the flip-flop circuit 3. By increasing the frequencies, the time integration of both timer counter 4 and 5 are promoted, and a masking time completion signal is output from a defrost masking timer 4 to an AND circuit, thus entering into the defrosting operation and enabling to prevent progressing of frosting.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a defrost control device for an air-cooled heat pump type air conditioner.

Conventional technology Conventionally, in air-cooled heat bombs and air-cooled air conditioners that sequentially connect a compressor, four-way valve, air-cooled outdoor heat exchanger, expansion device, and air-cooled indoor heat exchanger, the evaporation effect occurs during heating. Frost builds up on the outdoor heat exchanger, which reduces the efficiency of heat conversion (heating) of the evaporative refrigerant, making heating impossible, so the four-way valve is reversed to switch the flow of refrigerant. A so-called defrost operation is performed in which a condensed refrigerant is passed through an outdoor heat exchanger to melt frost by heat of condensation.

During this defrost operation, the method for detecting frost on the outdoor heat exchanger for performing the defrost operation is q!
This is done by indirect detection of r species. In other words, (1) Control by temperature and time of outdoor heat converter? ) Control is mainly performed by controlling the temperature of the outdoor heat exchanger, by time, or by controlling the outside air temperature. these are,
The former 0), and the latter? ), basically, when the temperature of the outdoor heat exchanger falls below a certain value (defrost temperature), defrost operation is performed within the allowed time (defrost chance time),
After continuing this operation, normal heating operation will be resumed unless the temperature of the outdoor heat exchanger rises above a certain value (defrost completion temperature) or the defrost time ends. controlled. Especially the latter? In the case of ), the outdoor heat converter temperature, which has the above-mentioned two constant values, is further shifted at a constant rate depending on the outside air temperature.

Problems to be Solved by the Invention However, in these conventional methods, when the outside temperature is relatively low, the permissible time (during the defrost period and when returning to heating operation, Since the outdoor heat exchanger switches to heating operation when defrosting is incomplete, there is a strong possibility that frost still remains on the outdoor heat exchanger.
If the defrost operation is repeated, the amount of frost remaining will increase, and furthermore, the lower part of the outdoor heat exchanger will accumulate as ice, resulting in a significant deterioration of heat exchange efficiency. The purpose is to better control defrost operation during operation and to reduce ice accumulation on an outdoor heat exchanger when the outside air temperature drops.

Means for Solving the Problems The present invention provides a defrost mask timer that counts multiple clocks output from one oscillation circuit, a defrost start temperature detection circuit, and a system that combines the defrost mask timer and the defrost start temperature detection circuit. , a defrost output circuit outputted via an AND circuit, a defrost chance timer that counts the clocks output multiple times from the other oscillation circuit, a defrost end temperature detection circuit, this defrost chance timer, and a defrost end temperature detection circuit. The output is output to the defrost output circuit via an OR circuit, and it has a logic circuit that enters a predetermined state when an input is applied, and maintains the previous state if no input is applied. It is similar to a flip-flop circuit.

Function: With this circuit configuration, when the outputs of the defrost mask timer and the defrost start temperature detection circuit are satisfied at the same time, a defrost operation value number 1 is output to the defrost output circuit, and the defrost operation is performed. , during this defrost operation, the defrost chance timer or
When any output from the defrost end temperature detection circuit is output, the heating operation is returned to.If the return is made by the flip-flop circuit or by the defrost charger/stimer, the defrost end temperature is This is stored in the 7 flip-flop circuit until the defrost recovery operation is performed by the detection circuit, and the frequency of both oscillation circuits is increased by the output of the flip-flop circuit to accelerate time integration, and the defrost mask timer and
This shortens the time of the defrost 0 stability timer and accelerates the next defrost operation.

Embodiment An embodiment of the present invention will be explained based on the drawings. (1
)and? ) is a logic circuit made of bistable elements that has two stable states at its output, and when an input is applied, the stable state changes to a predetermined state, and when no input is applied, it maintains the previous state. , an oscillation circuit that inputs the output from the 7-lip 70 tag circuit 3 for the purpose of changing the time within the ratio of the defrost operation to the heating operation, and outputs the output to the defrost mask timer 4 and the defrost chance timer 6; 6 is a defrost start temperature detection circuit, A
When it is output to the ND circuit 7 and simultaneously outputted to the defrost mask timer 4, it is output from the output terminal of the AND circuit 7 to the defrost output circuit 8. 9 is a defrost end temperature detection circuit, which outputs to the OR circuit 10;
It is output to the 7-rip 70-rip circuit 3. 11 is a west valve driven by the output from the defrost output circuit 8;
2 is an outdoor fan which is also controlled by the output from the defrost output circuit 8.

The defrost mask timer 4 is a timer that sets a time period during which defrosting is not performed even if the temperature condition of the outdoor heat exchanger is established as a temperature at which defrosting is performed, and the defrost chance timer 5 is a timer that sets a time when defrosting is not performed even if the temperature condition of the outdoor heat exchanger is established as a temperature at which defrosting is performed. This is a timer for forcibly returning to heating even if the heating return temperature conditions are not met, subject to a time limit.

In the above configuration, when the heating operation is continued, the defrost mask timer 4 that is counting the time
When the output of the defrost start temperature detection circuit 6 is satisfied, it is output to the AND circuit 7 via the output terminals 4 & e6+a, and is input from the AND circuit 7 to the defrost output circuit 8. Output terminals 8a, 8
via the four-way valve 11.b. Then, the output is output to the outdoor fan 12, the four-way valve 11 is reversed, and the outdoor fan 12 is stopped.
Defrost operation (cooling operation begins. While this defrost operation continues, the output of the defrost chance timer 6, which is countered by the output from the oscillation circuit 2, or the defrost end temperature detection circuit 9 detects the Either one of the outputs is outputted to the OR circuit 10 via the output terminal 5a or the output terminal 9, and
The circuit 10 outputs an output to the defrost output circuit 8, and the westward valve 11. and.

It is output to the outdoor 77/12, operates the outdoor 77/12, and excites the four-way valve 11 to return to heating operation. At this time, if the clip-frost circuit 3 is restored by the output of the defrost chance timer 6,
From then on, the defrost chance timer 6 waits until the defrost end temperature detection circuit 9 performs a return operation.
The 7-rip, 70-tub circuit 3 outputs the chest wave number of the oscillation port M1.2. By increasing this frequency, the time integration of both timer counters 3.4 is promoted, and the mask time end signal is ANDed from the defrost mask timer 4 earlier than the previous time.
It is output to the circuit and enters defrost operation to prevent the progress of frost formation.

It should be noted that, as a matter of course, it is necessary to consider the comfort of heating operation when determining the ratio of time reduction in the defrost mask timer 4 and the defrost chance timer 6. You may also consider changing the ratio.

Effects of the Invention As described above, the present invention provides a defrost mask timer and a defrost chance timer which are inputted from an oscillation circuit, and an AND circuit which is inputted by simultaneous outputs of the defrost mask timer and a defrost start temperature detection circuit. the defrost output circuit which is input via an OR circuit which is inputted depending on whether the output is from the defrost chance timer or the defrost end temperature detection circuit, and the defrost chance timer. An OR circuit and a free lag frog circuit are provided to store that when the west valve is switched to heating operation through the defrost output circuit, an output (return operation) will be performed from the defrost end temperature detection circuit thereafter. This 7-lip frost circuit is designed to change the defrost time within the ratio of the defrost operation time to the heating operation time, so if the defrost chance timer is busy, the defrost will be forcibly terminated. In this case, the next defrost mask timer can be shortened and the defrost operation can be started earlier. Therefore, the defrost operation can be well controlled during the heating operation, and the heat exchange efficiency is increased, even when the outside temperature is low. This has the effect of reducing the amount of ice accumulated in the outdoor heat exchanger.

[Brief explanation of the drawing]

The figure is a block diagram of a defrost control device for an air-cooled heat pump type air conditioner according to an embodiment of the present invention. 1.2... Transmission circuit, 3... Flip-flop circuit, 4... Defrost mask timer, 6... Defrost chance timer, 6.
...Defrost circuit temperature detection circuit, 8...
- Defrost output circuit, 9...Defrost end temperature detection circuit.

Claims (1)

[Claims] Defrost mask timer input from oscillation circuit,
and a defrost output circuit that controls a four-way valve, an outdoor fan, etc. by simultaneous output from a defrost chance timer, the defrost mask timer, and the defrost start temperature detection circuit, and a defrost end temperature detection circuit that controls the four-way valve, outdoor fan, etc. by the output from the defrost chance timer, and the defrost end temperature detection circuit. The defrost output circuit inputs the output from the circuit and controls the four-way valve, outdoor fan, etc., and the defrost chance timer controls the four-way valve, outdoor fan, etc. via the defrost output circuit. 1. A defrost control device for a heat pump type air conditioner, comprising a flip-flop circuit for storing the time at which a defrost end temperature detection circuit outputs an output when the temperature is reached.