JPS60144546A - Controller of defrosting operation of air conditioner - Google Patents

Abstract

PURPOSE:To apply the detection of frosting having no misdetection to an outdoor heat exchanger, by providing the titled controller with the memory part storing a heating operation mode and a defrosting operation mode and an output part changing over the heating operation mode of the memory part into the defrosting operation mode through the result of operation of an operation part and putting out the same. CONSTITUTION:When a setting switch 17 is operated, cooling operation is performed, to begin with, and water which becomes ventilation resistance such as dew and frost to an outdoor heat exchanger 8 is made to evaporate. Then after that, the titled controller is made to operate for the fixed period of time M5, an operation current Ifan is applied to by a current transformer 11 and a value to be obtained by deducting a certain fixed value alpha from the current Ifan is made to keep stored in a memory element as a detecting current Ioff of frosting after the operating current of an outdoor blower 9 has become of a stabilized state to some extent, and a reestablished value is used as the detecting current Ioff of frosting, in heating operation after that.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an air conditioner equipped with a control device capable of combined heating and cooling operation and capable of detecting frost formation on an outdoor heat exchanger when the outside air temperature is low. This invention relates to a defrosting operation control device.

Conventional configuration and its problems Conventionally, when an air conditioner that can perform both heating and cooling operations is in heating operation, when the outside air temperature is low, frost begins to form on the outdoor heat exchanger 3-Bage exchanger, resulting in a decrease in heating capacity. To sleep,
Defrosting operation is performed at certain timings.

In this case, as a means for detecting frost formation, a temperature sensor is attached to the refrigerant inlet, outlet, or hairpin part of the outdoor heat exchanger, and means for detecting frost formation by detecting that the temperature falls below a certain certain level; There are means for detecting frost formation based on the current value of the compressor, and means for detecting frost formation by detecting the temperature of an indoor heat exchanger or a decrease in the blowout temperature.

However, means for detecting frost formation based on the temperature of the outdoor heat exchanger may incorrectly detect frost formation even if no frost formation occurs when the outside air drops and the evaporation pressure drops. Furthermore, the means for detecting the current value of the compressor does not have a reliable relationship with the state of frost formation because the discharge pressure changes depending on the load on the indoor side and the current of the compressor also changes accordingly. Also,
The means for detecting the temperature of the indoor heat exchanger or the temperature of its blown air is the same as the means for detecting the current of the compressor. Therefore, false detection may occur even when frost has not formed, and unnecessary defrosting operation may interrupt heating and reduce heating capacity, resulting in poor feeling due to a drop in blowout temperature and damage to the refrigeration cycle. There were problems such as noise when switching.

Purpose of the Invention The present invention solves the above-mentioned conventional drawbacks, and aims to enable efficient refrigeration cycle operation by starting defrosting according to the amount of frost on the outdoor heat exchanger. is one of its objectives.

Structure of the Invention To achieve this object, the present invention measures the currents of the compressor, four-way valve, outdoor blower, indoor blower, and outdoor blower that make up the refrigeration cycle, as shown in FIG. A defrost control device is installed that detects frost formation on the outdoor heat exchanger during operation and starts a defrost operation mode.
This defrosting control device is set in advance with a current measuring device (page 6) that measures the current of the outdoor blower, an input section that inputs the output of this current measuring device, and a signal of the input section, and starts fc defrosting operation. a calculation unit that calculates and compares all current values; a storage unit that stores the heating operation mode and the defrosting operation mode; and an output that switches the heating operation mode of the storage unit to the defrosting mode based on the calculation result of the calculation unit. It is composed of parts.

Furthermore, in the present invention, in the above configuration, a preset current value for starting the defrosting operation can be arbitrarily varied.

With this configuration, frost formation on the outdoor heat exchanger can be detected without false detection.

DESCRIPTION OF EMBODIMENTS Hereinafter, the present invention will be described with reference to FIGS.
This will be explained with reference to FIG.

First, the refrigeration cycle configuration will be explained with reference to FIG.

In the figure, 1 is an indoor unit, an indoor heat exchanger 2,
It is also equipped with an indoor blower 3, etc.

4 is an outdoor unit, and a compressor 6. Four-way valve6. Aperture 6 page device 7. Outdoor heat exchanger8. It is equipped with an outdoor blower 9 equipped with a propeller fan. The refrigerant flows as shown by solid line arrows during heating operation, and flows as shown by broken line arrows during true cooling operation and defrosting operation.

Next, the configuration of the electric circuit will be explained with reference to FIG.

Components that are the same as those in FIG. 2 are designated by the same reference numerals and their explanation will be omitted.

In the figure, 10 is a power switch, 11 is a current transformer (hereinafter referred to as CT), 12, 13, 14 . 16 are outdoor blowers 9. Four-way valve6. An electromagnetic switch 17 for controlling on/off of the compressor 5 and the indoor blower 3 is a setting switch provided for defrosting detection, and the current setting value for defrosting detection in the outdoor blower 9 is fully variable. Specifically, a well-known configuration such as changing the reference input value may be used, so a detailed explanation will be omitted.

Reference numeral 16 denotes an electronic control device including a microprocessor (LSI) i for controlling the electromagnetic switches 12, 13, 14, and 15, and is equipped with the function realizing means shown in FIG. Also,■
is the power supply.

7 pages Note that this circuit is mainly configured for heating operation.

Next, the operation of the electronic control unit 16 will be explained using the timing chart of FIG. 4.

In addition, the chart shows time Ti on the horizontal axis, rotation speed Dpm of the outdoor fan 9 on the vertical axis, and current (engine f) of the outdoor fan 9 on the vertical axis.
an) - electromagnetic switch 14 for the compressor 6. Electromagnetic switch 12 for outdoor blower 9. An electromagnetic switch 13 for the four-way valve 6 is used. Also, I in the current Ifan. ff is a set current value for frost detection.

First, if no frost is observed on the outdoor heat exchanger 8 (T, ~
At T2), the rotational speed of the outdoor blower 9 is also stable, and the current Ifan flowing therein is also high and stable.

Next, when frost formation begins (T2 to T3), the ventilation resistance of the outdoor heat exchanger 8 gradually increases, and due to this, the rotation speed of the outdoor blower 9 naturally decreases, and the current Ifan also decreases. Therefore, as at time 13, the operating current of the outdoor fan 9 is set to a certain constant value I. When the temperature drops below ff, the electronic control unit 16 regards this as a defrost signal and enters the defrost cycle. In that state (after T3), the outdoor blower 9. Four-way valve 6 is OFF
It works and starts defrosting.

The above control contents are expressed in the flowchart shown in FIG.

Next is the frost detection current I. The resetting of ff will be explained using the flowchart shown in FIG.

When the setting switch 17 shown in FIG. 3 is operated, a cooling operation is first performed to evaporate moisture such as dew and frost that causes ventilation resistance in the outdoor heat exchanger 8. After that, the operation current of the outdoor fan 9 is stabilized to some extent by operating the outdoor fan 9 for a certain period of time, inputting the operating current "fan" and subtracting a certain step value α from the current amount fan. The amount of frost detection current I.ff is stored in the memory element, and in the subsequent heating operation, the reset value is used as the frost detection current I.ff.Also, if the setting switch 17 is not operated The value β set at the time of manufacture is used as the frost detection current I.ff.

Effects of the Invention Page 9 As is clear from the above embodiments, the present invention detects the amount of frost formation using the amount of current of the outdoor blower, so the amount of frost formation can be grasped more directly than the conventional frost detection current. Unnecessary frost protection operation can be eliminated and the heating effect will not be reduced. Furthermore, since the rotational speed of the outdoor blower changes regardless of where frost forms on the heat exchanger, the temperature of the heat exchanger can be detected more accurately than in conventional configurations that detect the temperature of the heat exchanger. In addition, since the current value that starts defrosting operation can be arbitrarily varied, there are variations in the operating current caused by manufacturing processes, differences in ventilation resistance caused by the installation conditions of the air conditioner, etc. The frost detection current can be reset even if there are variations in the operating current due to voltage changes due to power conditions, changes in the operating current of the blower itself due to aging, or changes in the ventilation resistance of the outdoor heat exchanger due to dirt, etc. By setting this, it is possible to always perform accurate frost detection.

[Brief explanation of drawings]

Figure 1 shows an embodiment of the 10-page defrosting operation control for an air conditioner according to the present invention! A refrigeration cycle diagram of an air conditioner equipped with a defrosting operation control device, Fig. 3 is an electrical system diagram related to the defrosting cycle in the air conditioner, and Fig. 4 is a diagram of the air conditioner 9.
Timing chart during the defrosting cycle of the machine, No. 5
The figure is a flowchart during the defrosting cycle of the defrosting operation control device in the same air conditioner, and FIG. 6 is a flowchart when setting the frost detection current in the same defrosting operation control device. 2...5 indoor heat exchangers, 5...compressor, 6...four-way valve, 7...throttling device, 8
...Outdoor heat exchanger, 9...Outdoor blower, 16...Electronic control unit, 17...Setting switch. Name of agent: Patent attorney Toshio Nakao Haga 1st person
5th page 6th figure Iaf6 setting interval (G continuous battle I good 51 sheet S pupil λ force "' Iall・β lFI: 4 to 7% 1 interlude / 2. / 4.15 0s J lFF 1. Face Feng 5 CD+)4tQ”1. I & λK J5n 10H・-bi

Claims (3)

[Claims] (1) Compressor, four-way valve, indoor heat exchanger, throttling device. A control method that includes an outdoor blower, detects frost formation on the outdoor heat exchanger rate during heating operation by measuring the current of the outdoor blower blowing air to the outdoor heat exchanger, and starts a 1 defrosting operation mode. Air conditioner with equipment-Yunshun 1, 4, Yuan County, Nailu County
I'm used to ice cream. (2) Compressor, four-way valve, indoor heat exchanger, throttling device. The outdoor heat exchangers are connected in a ring to form a refrigeration cycle capable of air-conditioning/heating operation, the indoor refrigeration cycle is provided with an indoor blower and an outdoor blower, and the current of the outdoor blower blowing air to the outdoor heat converter is measured. A defrost control device is provided that detects frost formation on the outdoor heat exchanger during heating operation and starts a defrost operation mode. Defrosting operation control for an air conditioner, comprising a storage section that stores an operation mode and a defrosting operation mode, and an output section that switches and outputs a heating operation mode in the storage section to a defrosting operation mode based on the calculation result of the calculation section. Device. (3) Current to start preset defrosting operation