JPH05223360A - Air conditioner - Google Patents

Abstract

PURPOSE:To provide a safe air conditioner which can be interrupted in its operation by detecting mistaken opening of a connection valve in a short time and of previously preventing a compressor from being damaged. CONSTITUTION:A temperature sensor is mounted at an arbitrary location on a piping extending from a cappillary tube 4 of a refrigeration cycle to a connection valve 7. When there is opened connection valves 5, 7 between an outdoor unit and an indoor unit upon the initiation of the operation, refrigerant flows so that detection temperature by a temperature sensor 9 is greatly changed But, if any of the connection valves 5, 7 is closed, the refrigerant does not flow, so that the temperature detected by the temperature sensor 9 is substantially not changed. From this, it is detected that the connection valves 5, 7 are closed, whereby the compressor 1 is immediately interrupted in its operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separate type air conditioner composed of an outdoor unit and an indoor unit.

[0002]

2. Description of the Related Art A separate type air conditioner consisting of an outdoor unit and an indoor unit is provided with a connecting valve in a refrigeration cycle pipe between the outdoor unit and the indoor unit. This connection valve is a two-way valve that opens and closes by hand, and when it is opened during installation work, it functions to bring the refrigeration cycle into conduction and allow the refrigerant to flow.

If the operation is started without opening the connecting valve, the compressor will be in a vacuum operation. If this happens, the discharge port of the compressor will have an abnormally high temperature and the compressor motor will overheat, damaging the compressor. Therefore, conventionally, a pressure switch, a so-called low-pressure switch, is attached to the low-pressure side of the refrigeration cycle, and the operation is stopped when the low-voltage switch operates.

That is, if the operation of the compressor continues without the refrigerant flowing, the pressure on the low pressure side will decrease and the low pressure switch will operate. In that case, however, the operation is stopped to ensure the safety of the compressor. I am trying.

[0005]

However, if the connecting valve is forgotten to be opened, it takes a long time of 1 minute or more before the low pressure switch is actuated. Therefore, the compressor may eventually be damaged.

The present invention takes the above circumstances into consideration,
The purpose is to provide an air conditioner with excellent safety that can detect the failure to open the connection valve in a short time and stop the operation, and prevent damage to the compressor. To do.

[0007]

An air conditioner according to claim 1 is an outdoor unit having a compressor, an outdoor heat exchanger and a decompressor, an indoor unit having an indoor heat exchanger, the outdoor unit and the indoor unit. A first connecting valve and a second connecting valve for connecting with, and the compressor, the outdoor heat exchanger, the decompressor, the first connecting valve, the indoor heat exchanger, and the second connecting valve are sequentially connected. The refrigeration cycle, the temperature sensor attached at an arbitrary position from the decompressor of the refrigeration cycle to the second connecting valve, and the operation of each of the connecting valves according to the change in the temperature detected by the temperature sensor at the start of operation. A detection means for detecting the open / closed state and a control means for stopping the operation of the compressor when the detection means detects the closed state.

According to another aspect of the air conditioner, an outdoor unit having a compressor and an outdoor heat exchanger, an indoor unit having a decompressor and an indoor heat exchanger, and an outdoor unit for connecting the outdoor unit and the indoor unit. A refrigeration cycle in which the first connecting valve and the second connecting valve are sequentially connected to the compressor, the outdoor heat exchanger, the first connecting valve, the decompressor, the indoor heat exchanger, and the second connecting valve, and The temperature sensor installed at any position from the first connection valve to the second connection valve of the refrigeration cycle, and the opening / closing state of each connection valve according to the change in the temperature detected by the temperature sensor at the start of operation. Detecting means for detecting, and control means for stopping the operation of the compressor when the detecting means detects a closed state.

[0009]

In any of the air conditioners of claims 1 and 2, the first connecting valve and the second connecting valve are provided at the start of operation.
If both the connection valves are open, the refrigerant flows and the temperature detected by the temperature sensor changes significantly. However, if either the first connection valve or the second connection valve is closed, the refrigerant does not flow, and therefore the temperature detected by the temperature sensor hardly changes, and the connection valve is in the closed state. Is detected and the operation of the compressor is stopped.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, an outdoor heat exchanger 3 is connected to a discharge port of a compressor 1 via a four-way valve 2. One end of a first connecting valve 5 is connected to the outdoor heat exchanger 3 via a capillary tube 4 which is a decompressor, and the other end of the first connecting valve 5 is connected to the indoor heat exchanger 6. One end of the second connecting valve 7 is connected to the indoor heat exchanger 6,
The other end of the second connecting valve 7 is connected to the suction port of the compressor 1 via the four-way valve 2.

That is, a heat pump type refrigeration cycle is constituted, and during the cooling operation, the refrigerant discharged from the compressor 1 flows in the direction of the solid line arrow in the drawing, and the outdoor heat exchanger 3 is a condenser,
The indoor heat exchanger 6 works as an evaporator. During the heating operation, by switching the four-way valve 2, the refrigerant discharged from the compressor 1 flows in the direction of the dashed arrow in the figure, and the indoor heat exchanger 6 functions as a condenser and the outdoor heat exchanger 3 functions as an evaporator. A high pressure switch 8 is attached to the high pressure side pipe between the discharge port of the compressor 1 and the four-way valve 2.

From the capillary tube 4 to the connecting valve 7
To any position, for example capillary tube 4
A temperature sensor 9 is attached to a pipe between the connection valve 5 and the connection valve 5. An outdoor fan 11 is provided near the outdoor heat exchanger 3, and an indoor fan 12 is provided near the indoor heat exchanger 6.

Thus, the outdoor unit A is constituted by the compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the capillary tube 4, the high pressure switch 8, the temperature sensor 9 and the outdoor fan 11. At least the indoor heat exchanger 6 and the indoor fan 12 configure an indoor unit B.

The connecting valves 5 and 7 are for connecting the outdoor unit A and the indoor unit B, and when opened by manual operation by a worker at the time of completion of installation, serve to allow the refrigerant to flow between both units. do. The control circuit is shown in FIG.

The outdoor unit A includes an outdoor controller 20. The outdoor control unit 20 includes a microcomputer and its peripheral circuits, and is connected to an external commercial AC power supply 21. The outdoor control unit 20 includes a compressor motor 1M,
Four-way valve 2, indoor fan motor 12M, high pressure switch 8,
The temperature sensor 9 is connected.

The indoor unit B includes an indoor control section 30. The indoor control unit 30 includes a microcomputer and its peripheral circuits, and is connected to the outdoor control unit 20 via a power supply line 41 and a serial signal line 42. A remote control type operation device (hereinafter, abbreviated as remote controller) 31, an indoor temperature sensor 32, and an indoor fan motor 11M are connected to the control unit 30. The outdoor control unit 20 and the indoor control unit 30 use the serial signal line 4
The following functional means are provided by mutually performing the data transfer in synchronization with the power supply voltage using 2.

(1) Control means for comparing the detected temperature of the indoor temperature sensor 32 with the set indoor temperature of the remote controller 31 during operation and controlling the operation of the compressor 1 on and off according to the comparison result. (2) Detection means for detecting the open / closed state of the connection valves 5 and 7 in response to changes in the temperature detected by the temperature sensor 9 at the start of operation. (3) Control means for stopping the operation of the compressor 1 when the detection means detects the closed state. (4) Control means for stopping the operation of the compressor 1 when the high pressure switch 8 is actuated due to an abnormal increase in the high pressure side pressure. Next, the operation of the above configuration will be described with reference to the flowchart of FIG. It is assumed that the installation of the outdoor unit A and the indoor unit B is completed and the first cooling operation is started.

At the start of this operation, the temperature detected by the temperature sensor 9 is first taken in as T ₁ , and then the time count t
After a fixed time t ₁ (for example, 30 seconds) based on the above, the temperature detected by the temperature sensor 9 is taken in as T ₂ this time. Further, since the cooling operation is performed, the temperature T ₂ to the temperature T ₁
Is subtracted to obtain the temperature change ΔT (= T ₂ −T ₁ ). If the connecting valves 5 and 7 are properly opened, the refrigerant flows between the units A and B, the outdoor heat exchanger 3 functions as a condenser, and the indoor heat exchanger 6 functions as an evaporator.

In this case, as shown in FIG. 4, the temperature of the refrigerant flowing from the capillary tube 4 to the connecting valve 5, that is, the temperature detected by the temperature sensor 9 decreases as the operation proceeds. Therefore, the temperature change ΔT has a negative value (ΔT <0). This is the connecting valve 5,7
Corresponds to the detection result that the is open, and the operation is continued under the judgment that it is normal. However, the connection valve 5,
If any one of 7 is closed, the refrigerant does not flow between the units A and B. In this case, as indicated by the broken line in FIG. 4, the temperature detected by the temperature sensor 9 shows a temperature change opposite to that in the normal state or hardly changes (ΔT ≧ 0). This corresponds to the detection result that at least one of the connecting valves 5 and 7 is closed, and the operation of the compressor 1 is immediately stopped when it is determined that there is an abnormality. On the other hand, if the heating operation, a predetermined time t ₁ after temperature T ₂ is subtracted from the temperature T ₁ of the starting point, the temperature change ΔT (= T ₁ -T ₂₎ is obtained. If the connecting valves 5 and 7 are properly opened, the refrigerant flows between the units A and B, the indoor heat exchanger 6 functions as a condenser, and the outdoor heat exchanger 3 functions as an evaporator.

In this case, as shown in FIG. 5, the temperature of the refrigerant flowing from the connecting valve 5 to the capillary tube 4, that is, the temperature detected by the temperature sensor 9 rises as the operation proceeds. Therefore, the temperature change ΔT has a negative value (ΔT <0). This is the connecting valve 5,7
Corresponds to the detection result that the is open, and the operation is continued under the judgment that it is normal. However, the connection valve 5,
If any one of 7 is closed, the refrigerant does not flow between the units A and B. In this case, as indicated by the broken line in FIG. 5, the temperature detected by the temperature sensor 9 shows a temperature change opposite to that in the normal state, or hardly changes (ΔT ≧ 0). This corresponds to the detection result that at least one of the connecting valves 5 and 7 is closed, and the operation of the compressor 1 is immediately stopped when it is determined that there is an abnormality.

In this way, by catching the temperature change due to the flow of the refrigerant between the units A and B, it is possible to forget to open the connecting valves 5 and 7 within a short time before the change in the low pressure side appears. It is possible to detect and stop the operation.

Therefore, the vacuum operation of the compressor 1 can be avoided, and the abnormal temperature rise of the discharge port of the compressor 1 and the overheating of the compressor motor 1M can be prevented, and the safety of the compressor 1 is ensured. It

In the above embodiment, the temperature sensor 9 is attached to the pipe between the capillary tube 4 and the connecting valve 5, but it may be attached to any pipe as long as it extends from the capillary tube 4 to the connecting valve 7. The same effect can be obtained. Next, a second embodiment of the present invention will be described.

Here, as shown in FIG. 6, the capillary tube 4 is provided in the indoor unit B, and the compressor 1, the outdoor heat exchanger 3, the first connecting valve 5, the capillary tube 4, and the indoor heat exchanger 6 are provided. The second connection valve 7 is sequentially connected to form a heat pump refrigeration cycle.

A temperature sensor 9 is attached to the pipe extending from the connecting valve 5 to the capillary tube 4. The temperature sensor 9 may be attached at any position as long as it is a pipe extending from the connecting valve 5 to the connecting valve 7. In the control circuit, as shown in FIG.
The temperature sensor 9 is connected to the outdoor control unit 30 of the indoor unit B. The operation is the same as in the first embodiment, and will not be repeated here.

[0027]

As described above, according to the present invention,

In both the air conditioner according to the first aspect and the second aspect, the temperature change based on the flow of the refrigerant between the outdoor unit and the indoor unit is detected, and the open / closed state of the connecting valve is detected from the temperature change. Since the operation of the compressor is stopped when the closed state is detected, the operation can be stopped by detecting the forgetting to open the connecting valve in a short time, and the damage of the compressor can be prevented. The safety can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a control circuit of the same embodiment.

FIG. 3 is a flow chart for explaining the operation of the embodiment.

FIG. 4 is a graph showing changes in temperature detected by a temperature sensor during cooling operation in the example.

FIG. 5 is a graph showing changes in temperature detected by a temperature sensor during heating operation in the example.

FIG. 6 is a configuration diagram of a refrigeration cycle according to a second embodiment of the present invention.

FIG. 7 is a configuration diagram of a control circuit of the same embodiment.

[Explanation of symbols]

1 ... Compressor, 2 ... Four-way valve, 3 ... Outdoor heat exchanger, 4 ... Capillary tube (pressure reducer), 5 ... First connection valve, 6
... indoor heat exchanger, 7 ... second connection valve, 9 ... temperature sensor, 20 ... outdoor controller, 30 ... indoor controller.

Claims (2)

[Claims] 1. An outdoor unit having a compressor, an outdoor heat exchanger, a decompressor, an indoor unit having an indoor heat exchanger, a first connecting valve for connecting the outdoor unit and the indoor unit, and a first connecting valve. A refrigeration cycle in which the two connecting valves, the compressor, the outdoor heat exchanger, the pressure reducer, the first connecting valve, the indoor heat exchanger, and the second connecting valve are sequentially connected, and the decompressor of the refrigerating cycle 2 a temperature sensor attached at an arbitrary position up to the connection valve, a detection means for detecting the open / closed state of each connection valve according to a change in the temperature detected by the temperature sensor at the start of operation, and the detection means. An air conditioner comprising: a control unit that stops the operation of the compressor when a closed state is detected. 2. An outdoor unit having a compressor and an outdoor heat exchanger, an indoor unit having a decompressor and an indoor heat exchanger, a first connecting valve and a first connecting valve for connecting the outdoor unit and the indoor unit. 2 connection valves,
A refrigeration cycle in which the compressor, the outdoor heat exchanger, the first connection valve, the pressure reducer, the indoor heat exchanger, and the second connection valve are sequentially connected, and the first connection valve to the second connection valve of the refrigeration cycle A temperature sensor attached at an arbitrary position over the valve, a detection means for detecting the open / closed state of each of the connection valves according to a change in the temperature detected by the temperature sensor at the start of operation, and this detection means indicates a closed state. An air conditioner comprising: a control unit that stops the operation of the compressor when detected.