JPH0350379Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a heat pump multi-type air conditioner.

(Prior technology) 1 equipped with a compressor, a four-way switching valve, and an outdoor heat exchanger
A heat pump multi-type air conditioner consists of a single outdoor unit connected to multiple indoor units each equipped with an indoor heat exchanger and whose operation is controlled individually.
It has been well known for a long time. When a heat pump multi-type air conditioner with such a configuration is operated for heating, frost will form on the outdoor heat exchanger due to a drop in outside air temperature, etc., so refrigerant circulation is required to remove the frost. A defrosting operation is performed in which the route is a reverse cycle and the discharge gas of the compressor is supplied to the outdoor heat exchanger. In order to prevent cold air from blowing out from the indoor unit when restarting the operation after the defrosting operation is completed, the operation of the indoor unit is not restarted until the high pressure reaches a set pressure or higher.

(Problem to be solved by the invention) In the above conventional example, when any of the indoor units is stopped, the heating liquid line solenoid valve of the stopped indoor unit will circulate the refrigerant after the defrosting operation is completed. It typically remains closed even after the path returns to the heating cycle. However, in such cases, refrigerant condenses and accumulates in the indoor heat exchanger of the indoor unit that is in a stopped state between the time the defrosting operation ends and the time when the indoor unit operation resumes when the high pressure reaches the set pressure or higher. That will happen. Therefore, the amount of refrigerant circulating in the refrigerant path that includes the indoor unit in operation becomes insufficient, and the rate of increase in high pressure slows down.As a result, the time from the end of defrosting operation to the restart of indoor unit operation becomes shorter. There was a problem with the length of time.

This invention was made in view of the above points,
A sufficient amount of refrigerant is ensured by preventing liquid refrigerant from accumulating in the indoor heat exchanger of a stopped indoor unit between the end of defrosting operation and the restart of indoor unit operation. The purpose is to make it possible.

(Means for Solving the Problems) In the present invention, as a means for solving the above problems, as shown in the drawings, a compressor 1, a four-way switching valve 2, and an outdoor heat exchanger 3 are provided. For one outdoor unit X, there are a plurality of indoor units A, B, which are each equipped with a heating liquid line solenoid valve 11 that is opened during heating operation and an indoor heat exchanger 14, and whose operation is controlled individually.
In the heat pump multi-type air conditioner connected to the four-way switching valve 2, a reverse cycle operation is performed to start and end a defrosting operation that removes frost from the outdoor heat exchanger 3. The high pressure P is the set pressure after the defrosting operation ends during the heating operation when the defrosting operation control means and either of the indoor units A, B, etc. are in a stopped state.
A determination means for determining whether P has increased to ₀ ;
From the end of the defrosting operation, the determining means determines that P
A control device 18 is provided with a heating liquid line solenoid valve opening/closing means that operates to open the heating liquid line solenoid valve 11 of the indoor unit that is in a stopped state until the time when ≧P ₀ is determined. ing.

(Function) In the present invention, the following effects can be obtained by the above-mentioned means.

That is, from the end of the defrosting operation to the time when the indoor unit operation is restarted (in other words, the time when the high pressure P becomes equal to or higher than the set pressure _P0 ), the heating liquid line solenoid valve 11 of the indoor unit that is in the stopped state is As a result, the liquid refrigerant is prevented from accumulating in the indoor heat exchanger 14 of the indoor unit that is in a stopped state. Therefore, it is possible to ensure a sufficient amount of refrigerant circulation in the refrigerant path including the indoor unit in operation, increasing the degree of rise in high pressure and shortening the time from the end of defrosting operation to the restart of indoor unit operation. This means that it is possible.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a refrigerant system diagram of a heat pump multi-type air conditioner according to an embodiment of the present invention.

This heat pump multi-type air conditioner includes a compressor 1, a four-way switching valve 2, an outdoor heat exchanger 3 equipped with an outdoor fan 16, a capillary tube 4 and an expansion valve 5 connected in parallel to form an expansion mechanism. , check valves 6 and 7 that allow refrigerant to flow only during cooling operation, a solenoid valve 8 and an accumulator 9 that are opened only during heating operation and are arranged to allow refrigerant to flow to the capillary tube 4.
For the outdoor unit It is constructed by connecting two indoor units A and B, each equipped with an indoor heat exchanger 14 equipped with an indoor fan 17 and check valves 12 and 13 that allow refrigerant flow only during heating and heating operations. The indoor units A and B are configured to be individually controlled. Here, the cooling liquid line solenoid valve 10
is opened by a cooling operation command, and the heating liquid line solenoid valve 11 is opened by a heating operation command.

Note that a bypass capillary tube 15 is connected in parallel to the heating liquid line solenoid valve 11. The bypass capillary tube 15 is connected to the indoor heat exchanger 14 in the indoor unit that is not in operation.
The function is to gradually return excess refrigerant that accumulates in the refrigerant system to the operating refrigerant system.

This heat pump multi-type air conditioner is configured to reversibly circulate the refrigerant through the switching operation of the four-way switching valve 2 to perform cooling (solid line arrow) or heating (dotted line arrow). has been done.

In this heat pump multi-type air conditioner, when frost formation occurs on the outdoor heat exchanger 3 due to a drop in outside temperature during heating operation, the four-way switching valve 2 is switched to reverse the refrigerant circulation path, A defrosting operation is performed by supplying the discharge gas of the compressor 1 to the outdoor heat exchanger 3.

The heat pump multi-type air conditioner of this embodiment is provided with a control device 18 for controlling opening and closing of the heating liquid line solenoid valve 11 during single room heating operation.

The control device 18 is constituted by a microcomputer and has functions as shown in the functional correspondence diagram of FIG.

That is, there is a defrosting operation control means that starts and ends the defrosting operation according to a signal from the day icer 19, and when the defrosting operation ends during the heating operation when either of the indoor units A or B is in a stopped state. determining means for determining whether the high pressure P, which is the input information from the high pressure pressure detector ₂₀ , has risen to the set pressure P0 set by the pressure setting device 21; Therefore, the heating liquid line solenoid valve 1 of the indoor unit whose operation is stopped until the time when P≧P ₀ is determined.
The heating liquid line electromagnetic valve opening/closing means operates to open the heating liquid line solenoid valve 1. In other words, this control device 18 controls the high pressure P obtained as input information from the high pressure pressure detector 20 from the end of the defrosting operation to the set pressure set by the pressure setting device 21.
Until the temperature reaches P ₀ or higher, the heating liquid line solenoid valve 11 of the indoor unit which is in a stopped state is forced to open.

Next, the heating operation control in the heat pump multi-type air conditioner of the illustrated embodiment will be explained with reference to the flowchart illustrated in FIG.

In the following description, a case will be described in which indoor unit A is in an operating state and indoor unit B is in a stopped state.

During heating operation by indoor unit A (at this time,
As in step _S2 , the heating liquid line solenoid valve 11 on the indoor unit A side is opened, and the heating liquid line solenoid valve 11 on the indoor unit B side is closed), and the outdoor heat exchanger 3 receives the outside temperature. When frost formation occurs due to cooling, etc., the day icer 19 operates to prompt the start of defrosting operation (step S ₃ ), and the defrosting operation control means switches the four-way selector valve 2 to the cooling cycle side, and at the same time, the indoor unit The indoor fan 17 on the A side is stopped (step S ₄ ). Therefore, a defrosting operation is performed in which the discharge gas of the compressor 1 is supplied to the outdoor heat exchanger 3 by reverse cycle operation. When the frost on the outdoor heat exchanger 3 is removed, a defrosting operation end signal is issued from the de-icer 19 (step _S5 ), and the four-way switching valve 2 is switched to the heating cycle side by the defrosting operation control means. At the same time, the heating liquid line solenoid valve 11 on the indoor unit B (stopped) side is opened by the heating liquid line solenoid valve opening/closing means (step _S6 ), but the heating liquid line solenoid valve 11 on the indoor unit A side is opened (step S6). The fan 17 continues to be stopped. After that, high pressure pressure detector 2
The determination means compares the high pressure P obtained as input information from 0 (step S ₇ ) with the set pressure P ₀ set by the pressure setting device 21, and determines that P≧
At the time when P ₀ (step S ₈ ), the heating liquid line solenoid valve 1 on the indoor unit B side is opened by the heating liquid line solenoid valve opening/closing means that receives the output signal from the determination means.
1 is closed (step _S9 ), and at the same time the indoor fan 17 on the indoor unit A side is restarted (step S9).
_S10 ). Therefore, at the end of defrosting operation (step _S5 )
to the point when P≧P ₀ (step S ₈ ),
The heating liquid line solenoid valve 11 on the indoor unit B side, which is in a stopped state, is forcibly opened, and liquid refrigerant accumulation in the indoor heat exchanger 14 on the indoor unit B side is prevented. As a result, a sufficient amount of refrigerant circulation is ensured in the refrigerant path during operation, the degree of increase in high pressure P is greatly increased, and operation of indoor unit A is restarted from the end of defrosting operation (in other words, , restart of the indoor fan 17) will be greatly shortened.

Although the present embodiment has been described with reference to two indoor units, the present invention is of course applicable to a heat pump multi-type air conditioner having two or more indoor units.

Further, although a microcomputer is employed as the control device 18, an electric circuit such as a relay or a comparator may be used instead.

(Effect of the invention) As described above, according to the invention, from the end of the defrosting operation to the time when the indoor unit operation is restarted (in other words, the high pressure P
until the set pressure P ₀ or higher), the heating liquid line solenoid valve 11 of the indoor unit in the stopped state is forcibly opened, and the heating liquid line solenoid valve 11 of the indoor unit in the stopped state is transferred to the indoor heat exchanger 14 of the indoor unit in the stopped state. Since the liquid refrigerant is prevented from accumulating, it is possible to ensure a sufficient amount of refrigerant circulation in the refrigerant path including the indoor unit in operation, and the degree of rise in high pressure is greatly increased, reducing the This has the practical effect of greatly shortening the time from the end of frost operation to the restart of indoor unit operation.

Furthermore, as a result of shortening the time from the end of the defrosting operation to the restart of the indoor unit operation, there is also the effect that the integral heating capacity is improved.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant system diagram of a heat pump multi-type air conditioner according to an embodiment of the present invention, FIG. 2 is a functional correspondence diagram of the control device in the heat pump multi-type air conditioner of the present invention, and FIG. , 1st
It is a flowchart for explaining the operation of the heat pump multi-type air conditioner shown in the figure. 1... Compressor, 2... Four-way switching valve, 3... Outdoor heat exchanger, 11... Heating liquid line solenoid valve, 14
...Indoor heat exchanger, 18...Control device, A, B...
…Indoor unit, P…High pressure, P ₀ …Set pressure,
X...Outdoor unit.

Claims (1)

[Scope of utility model registration request] For one outdoor unit X equipped with a compressor 1, a four-way switching valve 2, and an outdoor heat exchanger 3, a heating liquid line solenoid valve 11 and an indoor heat exchanger 14, which are opened during heating operation, are respectively provided. Moreover, in a heat pump multi-type air conditioner in which a plurality of indoor units A, B, etc., each of which is individually controlled, are connected, the outdoor heat exchanger 3 is switched on and off by reverse cycle operation by switching the four-way switching valve 2. A defrosting operation control means that acts to start and end a defrosting operation that removes frost, and a high pressure P after the defrosting operation ends during a heating operation when either of the indoor units A, B, etc. are in a stopped state. A determination means for determining whether the pressure has increased to the set pressure P ₀ , and heating of the indoor unit that is in a stopped state from the end of the defrosting operation to the time when the determination means determines that P≧P ₀ . A heat pump multi-type air conditioner characterized in that a control device 18 is provided with a heating liquid line solenoid valve opening/closing means that operates to open a heating liquid line solenoid valve 11.