JPH01155166A - Air conditioner - Google Patents

Abstract

PURPOSE: To obtain an air conditioner having an inexpensive refrigeration cycle in which heating capacity is not lowered even at the time of defrosting by bringing a temperature-sensitive tube for regulating the opening of a temperature type automatic expansion valve fixed to a refrigerant pipe on the suction side of a compressor into contact with a defrost pipe. CONSTITUTION: A temperature-sensitive tube 10 disposed closely to the suction side of a compressor 2 detects a low temperature to operate a temperature type automatic expansion valve 5 in the closing direction. A sensor 13 fixed to an outdoor heat exchanger 6 reacts on frost to open an on/off valve 14 provided in a defrost circuit 11 forcibly and removes frost by feeding high temperature refrigerant from the compressor 2 through the circuit 11 to the heat exchanger 6. Since the tube 10 detects high temperature refrigerant instantaneously to open the valve 5 when the valve 14 is opened, flow in the refrigeration cycle is not weakened nor interrupted.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to an air conditioner, and particularly to an air conditioner that can perform heating operation without reducing capacity during defrosting. .

(Prior Art) Generally, the air conditioners shown in FIGS. 3 and 4 are known as air conditioners having a defrosting function.

As shown in the figure, the refrigeration cycle a is constructed by sequentially connecting a compressor, a four-way valve C, an indoor heat exchanger d, an expansion valve e, and an outdoor heat exchanger f with a refrigerant pipe g. The expansion valve has the function of dividing the refrigeration cycle a into a high-pressure side and a low-pressure side, and increasing or decreasing the flow rate of the refrigerant to the outdoor heat exchanger f or the indoor heat exchanger d according to the temperature of the refrigerant. Valve e is adopted. FIG. 3 shows an example in which when the detected temperature of the outdoor heat exchanger f input to the computer k reaches the frosting temperature, the computer is forced to open the "C-expansion valve." A temperature-type automatic expansion valve is adopted as the expansion valve e, and the opening and closing of the temperature-type automatic expansion valve e is adjusted according to the temperature detected by a temperature-sensitive tube m attached to the suction side of the compressor. This is an example. Generally, a thermostatic automatic expansion valve e operates in the closing direction when the detected temperature is lower than a predetermined temperature, and in the opening direction when the detected temperature is higher.

Further, the refrigeration cycle a is capable of performing cooling operation and heating operation by switching the four-way valve C, but during heating operation, the outdoor heat exchanger is used! ,: Because frost forms, the heat exchange efficiency decreases. For this reason, in the examples shown in FIGS. 3 and 4, the defrosting circuit j that directly supplies the high temperature refrigerant discharged from the compressor to the outdoor heat exchanger f is connected to the discharge from the compressor l). A side panel and an outdoor heat exchanger f are connected, and this circuit j is provided with an on-off valve 1 that is operated by a sensor A attached to the outdoor heat exchanger f. However, if the temperature falls below a predetermined temperature, the sensor A releases the on-off valve i and the discharged gas is directly transferred to the outdoor heat exchanger f via the circuit j.
It is designed to be defrosted by being sent to the

(Problems to be Solved by the Invention) However, conventional air conditioners have the following problems.

(2) In the air conditioner shown in FIG. 3, a computer k is used to control the flow rate of the refrigerant, so although a good defrosting function is obtained, the cost is high.

■ In the air conditioner shown in Figure 4, when the temperature of the refrigerant sent from the outdoor heat exchanger f to the compressor becomes low due to frost formation, a temperature-sensing cylinder m attached to the suction side of the compressor senses a low temperature and operates the thermostatic automatic expansion valve C in the opening direction, and the outdoor heat exchanger f is defrosted by the action of the defrosting circuit j, and the refrigerant is sent out from the outdoor heat exchanger f. The thermostatic automatic expansion valve e remains operated in the closing direction until the temperature rises to a predetermined temperature.

As a result, the flow rate of the refrigerant from the compressor 1b to the indoor heat exchanger (j) decreases 17, and the heating capacity decreases.

In addition, this will compensate for the reduced heating capacity.
is required, which is one of the causes of high costs.

The present invention has been made in consideration of the above circumstances, and it is an object of the present invention to provide an air conditioner equipped with an inexpensive refrigeration cycle that does not reduce heating capacity even during defrosting.

[Structure of the Invention] (Means for Solving Point U) In order to solve the above problems, the present invention includes a compressor, an indoor heat exchanger, a thermostatic automatic expansion valve, and an outdoor heat exchanger. are sequentially connected with refrigerant piping to form a refrigeration cycle, and
In an air conditioner forming a defrosting circuit connecting the discharge side of the compressor and an outdoor heat exchanger, the valve is attached to the refrigerant piping on the suction side of the compressor and controls the opening degree of the thermostatic automatic expansion valve. The temperature-sensitive tube to be adjusted is configured by bringing the piping of the defrosting circuit into contact with it.

l) When frost forms on the outdoor heat exchanger, the high-temperature refrigerant discharged from the compressor passes through the defrosting circuit and enters the outdoor heat exchanger.
This outdoor heat exchanger will be heated and defrosted. At this time, the temperature sensing tube senses the temperature of the discharged high temperature refrigerant and operates the thermostatic automatic expansion valve in the opening direction, so that the flow of refrigerant is not obstructed (Example) Next An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, the overall configuration of a refrigeration cycle of an air conditioner according to the present invention will be explained with reference to FIGS. 1 and 2.゛As shown in the figure, the refrigeration cycle 1 of the present invention includes a compressor 2 and a four-way valve 3.
, an indoor heat exchanger 4 , a thermostatic automatic expansion valve 5 , and an outdoor heat exchanger 6 are successively connected by a refrigerant pipe 7 .

Further, an actuating element 8 extends from the thermostatic automatic expansion valve 5 in this refrigeration cycle 1, and this actuating element 8
A temperature sensing cylinder 10 is connected to the .

The temperature sensing tube 10 is installed near the suction side of the compressor 2 of the refrigerant distribution g7 via a heat insulating material 9 so as to sense the temperature of the refrigerant pipe 7.

The temperature-type automatic expansion valve 5 operates in the closing direction when the temperature sensing cylinder 10 senses a temperature lower than a predetermined temperature, and operates in the opening direction when the temperature sensing cylinder 10 senses a higher temperature. Further, the refrigeration cycle is provided with a defrosting circuit that directly sends high-temperature refrigerant discharged from the compressor to the outdoor heat exchanger 6.

Also in this embodiment, a defrosting circuit 11 is provided which branches off from the refrigerant pipe 7 connecting the discharge side of the compressor 2 and the four-way valve 3 and reaches the outdoor heat exchanger 6.

The refrigerant pipe 12 forming this circuit 11 is connected to the temperature sensing tube 10.
Alternatively, a feature of the present invention is that the tube is piped so as to be in contact with the temperature-sensitive cylinder heat insulating material 9.

Further, on the defrost circuit on the compressor 2 side from the contact portion between the defrost circuit 11 and the temperature-sensitive tube 10, there is an on-off valve 14 operated by a sensor 13 attached to the outdoor heat exchanger 6.
is provided.

Next, the operation of this embodiment will be described.

During heating operation of the air conditioner, high-temperature, high-pressure refrigerant discharged from the compressor 2 is sent to the indoor heat exchanger 4 via the four-way valve 3 and radiates heat while being condensed. It passes through and becomes low temperature and low pressure, and then evaporates and absorbs heat in the outdoor heat exchanger 6, and returns to the compressor 2 again via the four-way valve 3. If frost adheres to the outdoor heat exchanger 6 as a result of heat exchange during this heating operation, the heat exchange efficiency will decrease, and low-temperature refrigerant will return to the compression R2.

In this embodiment as well, as mentioned above, the temperature sensing tube 10 is located near the suction side of the compressor 2, so it senses low temperatures and operates the thermostatic automatic expansion valve 5 in the opening direction. However, in this case, as described above, the sensor 13 attached to the outdoor heat exchanger 6 reacts with the frost, and the on-off valve 14 provided in the defrosting circuit 11 is forcibly opened, causing the compressor 2 to pass through the high temperature The discharged refrigerant is sent directly to the outdoor heat exchanger 6 via this defrosting circuit 11 to defrost it.6 As described above, the defrosting circuit 11 of this embodiment is in contact with the temperature sensing cylinder 10. It is located in Therefore, when the on-off valve 14 is opened, the temperature sensing fVJ 10 instantly senses the temperature of the high temperature refrigerant.
The temperature-type automatic expansion valve 5 is operated in the opening direction,
Refrigeration cycle flow is not weakened or blocked.

[Effects of the Invention] Since the present invention is configured as described above, it exhibits the following excellent effects.

(1) During defrosting, when high-temperature refrigerant passes through the defrosting circuit, the temperature-sensing tube senses the temperature of the high-temperature refrigerant and operates the thermostatic automatic expansion valve in the opening direction, so the flow within the refrigeration cycle is not weakened. ,
There is no decrease in heating capacity.

(2) Since the flow within the refrigeration cycle is not weakened, the heating capacity does not decrease even when a liquid backlash of pressure avA occurs.

(3) Since the heating capacity can be maintained with a simple device, no computer or heater is required and costs are not high.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a preferred embodiment of the present invention, FIG. 2 is a partially enlarged schematic diagram of FIG. 1, and FIGS. 3 and 4 are schematic diagrams showing a conventional air conditioner. In the figure, 1 is a refrigeration cycle, 2 is a pressure WJta, 4 is an indoor heat exchanger, 5 is a thermostatic automatic expansion valve, 6 is an outdoor heat exchanger, 1
0 is a temperature sensing cylinder, and 11 is a defrosting circuit. Figure 1 Figure 2

Claims (1)

[Claims] A compressor, an indoor heat exchanger, a thermostatic automatic expansion valve, and an outdoor heat exchanger are sequentially connected with refrigerant piping to form a refrigeration cycle, and the discharge side of the compressor and the outdoor heat exchanger are connected in sequence. In an air conditioner that has a connected defrosting circuit,
An air conditioner characterized in that the piping of the defrosting circuit is brought into contact with a temperature-sensitive tube that is attached to the refrigerant piping on the suction side of the compressor and adjusts the opening degree of the thermostatic automatic expansion valve.