JPS61114042A - Defrosting control device of air conditioner - Google Patents

Abstract

PURPOSE:To shorten the defrosting time by a method wherein a heat accumulating operation utilizing the heat of refrigerant in refrigerating cycle is performed with a heat accumulating operation by which a heating cycle is operated, while the accumulated heat is utilized as a part of defrosting heat at a defrosting operation. CONSTITUTION:Just after the starting of defrosting operation or at the initial phase of defrosting thereof, a heat accumulation is performed at an utilizing side coil 6 of which heat exchanging capability is decreased due to the stopping of a fan 11 at the requirement of defrosting. The heat accumulation is performed by supplying a high pressure refrigerant to the utilizing side coil 6 by a heat accumulating means 1. At the detecting of the designated high area pressure by a pressure detecting means 2, the heat accumulating operation is changed- over from the heating cycle to the defrosting operation due to the cooling cycle. Thereby, the heat exchanging capability of the utilizing side coil 6 is increased, changed to the heat source for defrosting, a heat source side coil fan 12 is stopped, then the defrosting is performed.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a defrosting control device for an air conditioner that can shorten the defrosting time by storing the heat source necessary for defrosting in the refrigeration cycle during defrosting operation. When the air-to-air round heat source side coil in an air conditioner acts as an evaporator in the heat pump heating cycle, frost forms on the fill surface. It is a well-known technology that frost operation is performed, but there is no conventional defrosting method that performs this operation by switching from the heating cycle to cooling, and at the same time stopping the indoor fan to prevent cold drafts. In this case, due to the small heat exchange capacity of the coil on the user side, a sufficient heat source for defrosting can be obtained. Conventionally, measures have been taken such as installing a heat storage tank that can exchange heat with a refrigerant, or installing a heat storage tank that can heat the refrigerant in conjunction with the refrigeration circuit. 58-78460 (Problems to be Solved by the Invention) However, in this type of system that includes a refrigerant heater and a heat storage tank, the equipment cost is high and the machine body is large. There has been a problem that hinders the promotion of miniaturization.The present invention has been made by focusing on such conventional problems, and it is an object of the present invention to effectively provide a heat source for defrosting in the refrigeration cycle itself. We have developed a new technology,
This aims to simplify the device while shortening the time required for defrosting. (Means for solving problems). However, the present invention is shown in FIG.
Therefore, as is clear, the refrigeration cycle is switched from the 2m room cycle to the cooling cycle by the defrosting start command signal from the frosting detector (9) that detects the frosting state of the heat source side coil (51), and the user side coil (51) is switched from the refrigeration cycle to the cooling cycle. In an air conditioner in which defrosting is performed by stopping the 7 AN 011 described in [6], the defrosting control device is operated by three elements: the heat storage operation means il+, the pressure detection means (21°, and the heat storage operation stop means +31). The heat storage operation means (1) operates immediately after the defrosting start command signal is transmitted or during the defrosting operation after a certain period of time has elapsed, and changes the refrigeration cycle to the heating cycle. On the other hand, the pressure detection means (2) detects the discharge pressure of the refrigeration cycle and outputs the output at a set high range pressure within a range that does not overload the compressor. In addition, the heat storage operation stop means 131 has a structure in which the pressure detection means (
The heat storage operation means [11
It has a structure that deactivates the heating cycle, releases the forced holding of the heating cycle, and returns to the cooling cycle. [Effect] i
The present invention provides for the user-side filter (6) where the fan (10 is stopped and the heat exchange capacity is reduced) immediately after the start of defrosting or at the beginning of the defrosting operation when defrosting is still necessary.
By supplying high-pressure refrigerant by the heat storage operation means [11 and storing heat with the refrigerant, and storing this heat at the maximum allowable amount until the pressure detection means (2) is activated, switching to defrosting operation using the cooling cycle. During this defrosting operation, the heat exchange performance of the utilization side fill (6) can be enhanced to ensure an effective defrosting heat source. In this way, the defrosting time can be considerably shortened compared to the case where the cooling cycle is performed continuously, and the function equivalent to that provided with an auxiliary heat source can be exhibited. (Example) Examples of the present invention will be described below based on the accompanying drawings. FIG. 2 is a device circuit diagram of an air conditioner according to an embodiment of the present invention, in which the compressor (41, four-way switching valve (7), heat source side coil (5), check valve (IOA) A reversible refrigeration cycle is formed by a heating expansion valve (8) connected in parallel, a cooling and defrosting expansion valve (9I) with a check valve (IOB) connected in parallel, and a user-side coil (6). and
Heating operation can be performed by a heating cycle in which the refrigerant flows in the direction indicated by the solid line arrow, and cooling operation can be performed by a cooling cycle in which the refrigerant is caused to flow in the direction indicated by the broken line arrow. Furthermore, the cooling cycle allows defrosting operation during winter heating operation. In the blank note conditioner having the above configuration, a pressure switch (21) is attached to the high pressure side piping connected to the discharge side of the compressor (41), and the pressure switch (21) is installed within a range that does not overload the compressor (4). When the set high range pressure reaches, for example, 24°5 ￥A, two outputs are issued, and this pressure switch (2) constitutes the pressure detection means (2).The pressure switch (21 is the discharge Pressure is 24.55m
When the voltage rises to , an output is generated to close the normally open contact. On the other hand, in FIG. 2 (91 is a frost detector generally called a de-icer), a sensor a3 detects when frost grows to a predetermined thickness on the heat transfer surface of the heat source side coil (51, for example, the surface of the fins). The fins are connected to the fins, and the time corresponding to the time required for a limited amount of frost to grow on the surface of the fins (for example It is equipped with a timer mechanism that emits a signal for a certain period of time (for example, 10 minutes) with a cycle of 50 minutes), and when both the signal from the timer mechanism and the signal notifying frost formation on the sensor Q31 are transmitted, a defrosting start command is issued. For example, the signal is emitted as a switching of a normally open contact to close, and although not shown, this defrosting start command signal is generated by defrosting completion detection detected by an increase in refrigerant pressure in the heat source side coil (5), etc. The defrosting signal associated with the output contacts of these pressure switches (21 and deicer (9) The control device operates the heat storage operation means H1 and the heat storage operation means 5.
As mentioned above, the rotation stop means 131 can be easily constructed by a microcomputer having an input section, an output section, a storage section, and a central processing section. It can also be configured with a simple contact circuit. In Figure 3, (4M) is the compressor motor, (II
M) is a motor that drives the fan (11) of the usage side coil (6). (12M) C The motor that drives the fan α2 of the heat source side coil (51), (7S) is the solenoid of the four-way switching valve (7), I201 is closed by the excitation of the solenoid (203), and the compressor motor ( 4M], D is the room temperature controller, +221 is the cooling/heating switch, (231 is the solenoid (23A), normally open contact (23B)
), (230), normally closed contact (23D), (23E
), [241 is a solenoid (24
A). Auxiliary relays are shown each having a normally open contact (24B) and a normally closed contact (240). The 7 unmotor CIIM for the coil on the user side is connected to the auxiliary relay (
While 241 is de-energized, it is energized. The compressor motor (4M) is connected to the output contact of the room temperature controller (211) when the room temperature is low during heating and when the room temperature is high during cooling.
Electricity is applied when the crystal opens and closes. The heat source side coil 7 motor (12M) is energized while the auxiliary relay 9 is de-energized. The solenoid (7S) of the four-way selector valve (7) is energized while the cooling/heating selector switch □□□ is set to the cooling notch, is also set to the heating notch, and the auxiliary relay is energized. , operates to set the refrigeration cycle to the cooling cycle. Auxiliary relay 9 is energized when the cooling/heating selector switch is set to heating during the heating season, the auxiliary relay (2) is energized, and the pressure switch (21) is closed. On the other hand, in the example of the auxiliary relay, the cooling/heating selector switch is also set to heating, and the output contact of the de-iser (91) is closed (except for the auxiliary relay). In the circuit described above, the normally open contact (2) in the auxiliary relay
3B) corresponds to the heat storage operation means +11, while the solenoid (23A) of the auxiliary relay (23), the self-holding contact (23o) and the normally open contact (24B) of the auxiliary relay (241)
The series circuit with this corresponds to the heat storage operation stop means +31, and this will be clear from the operation description given below. In Figures 3 and 4, the de-Icer (9) is shown during heating operation.
) issues a defrost start command signal (closes the output contact)
(a) and auxiliary relay 9 is energized (b) and the contact (24
When the solenoid (7S) is opened, the fill fan (111) on the user side stops (li. At this time, the auxiliary relay is deenergized, so the four-way selector valve (7) is operated with the solenoid (7S) remaining demagnetized. can be,
Therefore, the refrigeration cycle continues with the heating cycle. , Thus, while the fan (111) remains stopped, high-pressure refrigerant gas flows to the user-side coil (6).
) the refrigerant temperature gradually rises and heat storage operation is performed. By the way, the high pressure immediately after the defrosting command signal is sent is 13
At about 5 u, the fin surface temperature is saturated corresponding to the pressure, and the temperature is 35 degrees, but in reality, heat exchange was performed by the fins + Il+, so the temperature was about 26 degrees Celsius, assuming the room temperature was 5 degrees Celsius. When the pressure and temperature rise from this state and reach a pressure of 24.5 mm, the pressure switch (2) detects this and closes the 4 output contacts.

[Because of the wing, energize the auxiliary relay (to). Therefore, by closing the contact point (23B), the four-way switching valve (71
The contact (23D), (23
When 1) is opened, the heat source side coil fan α2 stops [G], so the defrosting operation starts. The pressure-equivalent saturation temperature of %24.55U is 6)℃, but it is actually around 70℃, so 7゜-26m4
This means that heat storage corresponding to a temperature difference of 4° C. was performed in the utilization side coil (6). In this way, the defrosting operation starts, but it is important to check whether a predetermined period of time, for example, 10 minutes has passed since the DeIsa F91 started the defrosting operation (
b) Or coil (51) Is the thermosensor cylinder used to detect when the temperature reaches 10°C or higher and defrosting is complete?
If you check that the earlier signal is output, the output contact will open, and the auxiliary relay 4 will be deenergized, as shown in the figure.
As a result, the auxiliary relay device is also deenergized and the four-way switching valve +7
1, as a result of the excitation of the solenoid (7S) being released, the cooling cycle for defrosting is returned to the heating cycle, and
Heat source side coil fan Q21゜ User side fill fan (
III starts blowing air and heating operation starts (5). The time chart in Fig. 5 shows the operation mode described above over time, and it also shows that each element of pressure and temperature during defrosting operation is simply removed by the cooling cycle without any heat storage operation means H1 being taken. The graph in FIG. 6 compares the case with frosting. As is clear from these results, the defrosting time of the example using heat storage operation is approximately 8 minutes and 30 seconds, which is approximately 2 minutes shorter than the 10 minutes and 45 seconds of the comparison device. Ta. In the above embodiment, the heat storage operation means [H] for forcibly holding the refrigeration cycle in the heating cycle is performed at the same time as the defrosting start command signal is issued from the de-icer (9). The male side is shown in Figure 3. 1) It has a configuration in which a timer is added to the display circuit. In this example, the normally open contact (23B) of the auxiliary relay corresponds to the heat storage operation means il+, while the drive unit (25S) of timer 4 and the normally open contact (25A) of the timer )% time-limited normally closed contact (25B), the solenoid (24A) of the auxiliary coil (241), and the normally open contact (24B) correspond to the heat storage operation stop means (3). That is, the timer 4. Timing starts when the de-icer (9) closes the output contact, and the defrosting operation is performed by energizing the auxiliary relay by keeping the normally closed contact (25B) closed until a predetermined time period elapses, for example, 2 minutes. After 2 minutes, the contact (25B) is opened and the contact (25A) is closed to switch to the heat storage operation, and the pressure switch (21) is activated to stop the heat storage operation and restart the defrosting operation. The operating mode of this embodiment will be explained with reference to FIG. When the heat source side fan α2 and the user side fan 7 (III) stop, the four-way switching valve (71) switches the refrigeration cycle to the cooling cycle by excitation of the solenoid (7s). The heating operation is switched to the defrosting operation.The 0 timer is activated to determine that the set time limit of 2 minutes has elapsed.The auxiliary relay is deenergized and the four-way selector valve is activated.
7 for the heat source side coil at the same time as switching to the heating cycle side.
The so-called heat storage operation is started by driving the antenna 121. From this operating state, the pressure and temperature rise until the pressure reaches 24.
5512, the pressure switch 121 detects this angle and closes the output contact (e), energizing the auxiliary relay (241). Therefore, the contact (240) opens. The timer (to) is reset, and the auxiliary relay is energized by the return of the contact (25B) to close, and as a result, the heat source side coil fan (1
21 is stopped, and the four-way switching valve (7) is closed to the solenoid (
7S] switches to the cooling cycle (7S), and defrosting operation is performed again. In this way, defrosting operation is started, but when the defrosting completion signal or (7S) is output from the de-icer (9), the output is As a result of the contact opening, the auxiliary relay (241) is deenergized, the auxiliary relay 2 is deenergized, and the solenoid (7S) of the four-way switching valve (7) is deenergized, so it can be used for defrosting. The cooling cycle of is returned to the heating cycle, and both of the fans [+11,
α2 starts blowing air and heating operation starts (yJo) As shown in the graph in Figure 9 of operation mode 2 described above, as is clear from the graph, this example in which heat storage operation was performed is approximately 1 It was possible to shorten the defrosting time by about 1 minute. (Effects of the Invention) As described in detail above, the present invention can be used when the user-side coil fan is stopped immediately before starting the defrosting operation or during the defrosting operation. The heat storage operation that uses the heat of the refrigerant in the refrigeration cycle itself is performed by the heat storage operation that is performed during the heating cycle, and a part of the heat of melting the frost during the defrosting operation is secured, so the time required for defrosting is reduced. Moreover, as shown in the embodiment, all that is required is to switch the refrigeration cycle by switching the four-way switching valve, so handling is extremely simple, and the equipment cost is low. It subsides, - stone 0 has the effect of killing two birds.

[Brief explanation of the drawing]

Figure 1 is a block diagram clearly showing the configuration of the present invention, the JGZ diagram is a device circuit diagram of an air conditioner according to an embodiment of the present invention, and Figure 3 is a block diagram clearly showing the configuration of the present invention.
The figure is a developed diagram of an electric circuit according to an embodiment of the present invention, FIG. 4 is a flow S diagram showing the operating mode of the control device, and FIG. 5 is a time chart. Fig. 6 is a characteristic comparison diagram, Fig. 7 is a developed electric circuit diagram related to the Shinjitsu side of the present invention, Fig. 8 is a flow diagram showing the operation mode of the control device, and Fig. 9 is a characteristic comparison diagram 111. It is a diagram. +11... Heat storage operation means, [2I... Pressure detection means. ] 31... Heat storage operation stop means, (51... Heat source side coil. (6)... Utilization side coil, (91... Frost formation detector. [111... Fan. 9th B Shizuma

Claims (1)

[Claims] 1. Switch the refrigeration cycle from the heating cycle to the cooling cycle in response to the defrosting start command signal from the frost detector (9) that detects the frosting state of the heat source side coil (5), and switch the refrigeration cycle from the heating cycle to the cooling cycle. ) In an air conditioner configured to defrost by stopping the fan (11), the fan (11) is activated immediately after the defrosting start command signal is transmitted or during defrosting operation after a certain period of time has elapsed. A heat storage operation means (1) for forcibly holding the cycle in the heating cycle; and a pressure detection means for detecting the discharge pressure of the refrigeration cycle and outputting an output according to a set high-range pressure within a range that does not overload the compressor. (2) and the output generated by the pressure detection means (2) causes the heat storage operation means (1) to be deactivated;
A defrosting control device for an air conditioner, comprising a heat storage operation stop means (3) for releasing forced holding of a heating cycle.