JP2790521B2 - Heat pump type air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a four-way valve control for a separation type heat pump type air conditioner.

2. Description of the Related Art Conventionally, this kind of separation type heat pump type air conditioner is
As shown in the figure, for example, a compressor 1, a four-way valve 2, an outdoor heat exchanger 3,
The expansion valve 4, the three-way valve A5, the indoor heat exchanger 6, and the three-way valve B7 are connected by pipes to form a refrigeration cycle,
Is turned off during the cooling operation, a refrigeration cycle in which the refrigerant flows as indicated by the solid line 8 (hereinafter referred to as the cooling cycle), and turned on during the heating operation, and the refrigeration cycle in which the refrigerant flows as indicated by the dotted line 9 (Hereinafter, heating cycle). Further, a pressure sensor 10 is provided to control the low pressure during the cooling operation and the high pressure during the heating operation. And the four-way valve 2 during the heating operation.
The ON / OFF switching is performed as shown in the time chart of FIG. 4, when the heating operation start signal is received, the compressor 1 is started and the four-way valve 2 is also electrically switched so as to be in the heating cycle simultaneously. It was made to flow to the three-way valve B7 side through the dotted line 9.

In such a conventional configuration, in the normal heating operation, even if the start-up of the compressor 1 and the ON / OFF switching of the four-way valve 2 are performed at the same time, there is no problem at all. At that time, it is rare that the erroneously performs the heating operation with the three-way valve B7 closed, and in this case, the discharge side of the compressor 1 has a small volume up to the three-way valve B7, and in particular, the refrigerant In the case of a full state, at the time of starting the heating operation, when the activation of the compressor 1 and the switching of the four-way valve 2 are performed simultaneously,
The compressor 1 compresses a refrigerant in a liquid state, and a three-way valve is provided from the discharge side.
During the liquid sealing state until B7, the pressure is instantaneously transmitted to the three-way valve B7, and as shown in the time chart of FIG. 4, the pressure of the pressure sensor 10 is about 8 kg / cm ^{2 at the} beginning of operation. Approximately 100 kg / cm ² due to liquid compression after about 15 seconds
The above-mentioned abnormal high pressure occurs, and the pressure sensor 10 detects a high-pressure state, and before the operation is stopped, an abrupt pressure is already applied. .

The present invention solves such a problem.Even if the heating operation is performed with the three-way valve closed accidentally during the installation work, the sudden pressure increase applied to the pressure sensor is alleviated and abnormally high pressure is applied to break down. The purpose is to prevent accidents that occur.

Means for Solving the Problems A compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are respectively connected by pipes, and a discharge pipe and a suction pipe connecting the four-way valve and the compressor are provided. Constitutes a heat pump refrigeration cycle in which a bypass valve is provided in the middle of a bypass pipe provided between the four-way valve during heating operation.
The four-way valve is turned off and the bypass valve is turned on within a predetermined time after the start of the compressor at the start of the heating operation, while turning off the bypass valve.

Function With this configuration, the four-way valve is off immediately after the heating operation starts.
Since the compressor is started in the cooling cycle state and the bypass valve is turned ON to open the refrigerant, even if the refrigerant on the discharge side of the compressor is in a full state, the refrigerant remains in the outdoor heat exchanger and the compressor. The refrigerant in the liquid state around the pressure sensor is sucked into the compressor, and after a lapse of a predetermined time, the four-way valve is turned on to switch to the heating cycle side, and the bypass valve is turned off.
It closes as F, sets it to the normal heating operation state, and buffers the abnormal high pressure applied to the pressure sensor and the four-way valve at once.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. The same reference numerals as those in the conventional example denote the same items, and a description thereof will be omitted. For example, a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an expansion valve 4, a three-way valve A5, an indoor heat exchanger 6, and a three-way valve B7, each of which has a low internal pressure, such as a scroll type A heat pump having a bypass pipe connected between a discharge pipe 12 and a suction pipe 13 that connects the four-way valve 2 and the compressor 1 while being connected by a pipe, and the bypass pipe 11 is provided with the bypass valve 11 Constitute a refrigeration cycle,
The four-way valve 2 is turned off during the normal cooling operation, turned on during the normal heating operation, and the bypass valve 11 is turned on during the normal cooling and heating operation.
OFF. A pressure sensor to control low pressure during cooling operation and high pressure during heating operation
10 are provided. Then, the four-way valve 2 is turned on during the heating operation.
/ OFF switching and ON / OFF switching of the bypass valve 11 are performed by first starting the compressor 1 upon receiving a heating operation start signal as shown in the time chart of FIG. ON, for example, by a signal from a printed circuit board (not shown) incorporating a timer for 110 seconds,
After two seconds, the four-way valve 2 is turned on, and the bypass valve 11 is turned off.
And so on.

In the above configuration, if the heating operation is performed with the three-way valve B7 closed by mistake during the installation work,
As shown in the time chart of FIG. 2, the four-way valve 2 is OFF
In this state, the bypass valve 11 turns ON and opens, and the compressor 1
Immediately after the heating operation is started, the cooling cycle starts and the bypass valve 11 is turned on.

Therefore, the refrigerant discharged from the compressor 1 is supplied to the four-way valve 2
The refrigerant flowing through the solid line 8 to the outdoor heat exchanger 3 passes from the discharge pipe 12 to the bypass valve 11 of the bypass pipe 14 and the suction pipe 13.
The refrigerant flows back to the compressor 1 through the compressor. At this time, the liquid refrigerant around the pressure sensor 10 is sucked into the compressor 1, and the pressure of the pressure sensor 10 is
Once it drops to about 1 kg / cm ² (see Fig. 2), the refrigerant changes from a liquid state to a gas state. The refrigerant in the liquid state on the discharge side is pushed out by the outdoor heat exchanger 3 and immediately becomes a gaseous state, or returns to the suction side of the compressor 1 through the bypass valve 11 and evaporates. Becomes Thereafter, as shown in FIG. 2, when the four-way valve 2 is turned on, the bypass valve 11 is turned off and closed to switch to the normal heating cycle, the pressure of the pressure sensor 10 changes from low pressure to high pressure at once. Since the refrigerant on the discharge side is all in a gaseous state, the pressure rise is buffered, and the pressure does not suddenly become abnormally high. Then the pressure sensor 10 is a high pressure state immediately (roughly ^{· 25kg / cm 2 ~27kg / cm} 2
) Is detected and operation is stopped, and the three-way valve
Even if B7 is accidentally closed, the pressure sensor 10 prevents abnormal high pressure.

Effect of the Invention As is clear from the description of the above embodiment, the present invention provides a bypass valve in the middle of a bypass pipe provided between a discharge pipe and a suction pipe to turn off a four-way valve for a predetermined time at the start of heating operation. , The bypass valve is turned ON and opened, so even if the heating operation is performed with the three-way valve closed accidentally during the installation work, the liquid refrigerant flows to the outdoor heat exchanger through the four-way valve or the bypass valve. Flow to the suction side of the compressor, no abnormal pressure is applied to the pressure sensor. In addition, after a predetermined time, even if the four-way valve is turned on and the bypass valve is turned off and closed, there is no liquid refrigerant upstream of the pressure sensor, so high pressure is not applied to the pressure sensor at once. It has the effect of preventing the destruction accident of the pressure sensor and the four-way valve.

In addition, when the three-way valve is opened and the heating operation is started during normal installation work without error, the four-way valve is operated for a predetermined period of time.
In the method that only turns off the air conditioner, it operates in a cooling cycle when the indoor and outdoor temperatures are low, and the indoor fan does not run, generating an abnormal noise of refrigerant flowing from the indoor unit and giving the user discomfort. However, by turning on the bypass valve for a predetermined operation start time, the amount of refrigerant flowing to the indoor heat exchanger is reduced, and the effect of reducing abnormal noise of the indoor unit is also provided.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram of a heat pump type air conditioner according to one embodiment of the present invention, FIG. 2 is a time chart at the time of starting a heating operation of the heat pump type air conditioner, and FIG. 3 is a conventional heat pump type air conditioner. FIG. 4 is a refrigeration cycle diagram of the conditioner, and FIG. 4 is a time chart at the time of starting a heating operation of the conventional heat pump air conditioner. 1 ... Compressor, 2 ... Four-way valve, 3 ... Outdoor heat exchanger,
4 ... expansion valve, 6 ... indoor heat exchanger, 11 ... bypass valve, 12 ... discharge pipe, 13 ... suction pipe.

Claims (1)

(57) [Claims] A compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected by pipes, respectively, and a discharge pipe and a suction pipe connecting the four-way valve and the compressor are connected. A heat pump type refrigeration cycle in which a bypass valve is provided in the middle of a bypass pipe provided between
The four-way valve is turned on, the bypass valve is turned off, and at the start of heating operation, the heat pump air conditioner is configured to turn off the four-way valve and turn on the bypass valve for a predetermined time after the compressor is started. Machine.