JPH0431505Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to a heat pump type air conditioner.

(Conventional technology) An example of a conventional heat pump type air conditioner is the third example.
As shown in the figure, during heating operation, the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 passes through the discharge pipe 8 and the four-way valve 2, as shown by the broken line arrow, and enters the indoor heat exchanger 3, where it enters the indoor heat exchanger 3. Condenses and liquefies by dissipating heat. Next, this refrigerant liquid enters the throttle mechanism 4 and undergoes adiabatic expansion, and then enters the outdoor heat exchanger 5, where it absorbs heat from the outside air and evaporates. Thereafter, this refrigerant gas returns to the compressor 1 via the four-way valve 2.

When a certain amount or more of frost adheres to the outdoor heat exchanger 5 due to continued heating operation at low temperature and high humidity, a defrosting operation is performed. During defrosting operation, at the same time as the opening/closing valve 7 interposed in the bypass circuit 6, which has one end connected to the discharge pipe 8 of the compressor 1 and the other end connected to the refrigerant circuit between the throttling mechanism 4 and the outdoor heat exchanger 5, opens. The diaphragm mechanism 4 is fully opened. Then, most of the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 enters the outdoor heat exchanger 5 through the discharge pipe 8, the bypass circuit 6, and the on-off valve 7, where it radiates heat and melts the frost. As a result, it condenses and liquefies itself. Further, the remainder of the refrigerant gas discharged from the compressor 1 passes through the four-way valve 2, the indoor heat exchanger 3, and the throttling mechanism 4, enters the outdoor heat exchanger 5, where it is condensed and liquefied, and merges with the previously branched refrigerant. The air then returns to the compressor 1 via the four-way valve 2.

During cooling operation, the refrigerant discharged from the compressor 1 passes through the discharge pipe 8, four-way valve 2, outdoor heat exchanger 5, throttling mechanism 4, indoor heat exchanger 3, and four-way valve 2 to the compressor as shown by the solid arrow. Return to 1.

(Problems to be Solved by the Invention) In the conventional heat pump air conditioner described above, if frost adheres to the outdoor heat exchanger 5 during heating operation, the temperature of the compressor 1 will drop rapidly. Therefore, when defrosting operation is started from this state, there is a problem that the defrosting takes a long time because there is little heat for defrosting.

(Means for solving the problem) The present invention was proposed to solve the above-mentioned problems, and its gist consists of a compressor, a four-way valve, an indoor heat exchanger, a throttling mechanism, and an outdoor A heat pump comprising a refrigerant circulation circuit using a heat exchanger, and a bypass circuit having one end connected to a discharge pipe of the compressor and the other end connected to a refrigerant circuit between the throttling mechanism and the outdoor heat exchanger, and a first on-off valve provided therein. In the type air conditioner, a refrigerant reservoir is provided to exchange heat with the bypass circuit, and the refrigerant reservoir is connected to the refrigerant circuit between the indoor heat exchanger and the throttling mechanism via a refrigerant passage having a second on-off valve. Connect the first
The on-off valve and the second on-off valve are closed, and when frost is detected during heating operation, the second on-off valve is opened to perform heating operation, and after the temperature of the compressor rises to a predetermined temperature, the throttling mechanism and the first on-off valve are closed. and a heat pump type air conditioner characterized by being provided with a control device that performs a defrosting operation by opening a second on-off valve.

(Function) Since the present invention has the above configuration, during cooling operation, the refrigerant circulates through the compressor, the four-way valve, the indoor heat exchanger, the throttling mechanism, and the indoor heat exchanger in this order. During heating operation, the refrigerant is transferred to the compressor, four-way valve,
The indoor heat exchanger, throttling mechanism, and outdoor heat exchanger are circulated in this order. When frost formation is detected during heating operation, heating operation is performed by opening the second on-off valve, and a portion of the liquid refrigerant condensed and liquefied in the indoor heat exchanger is transferred to the refrigerant reservoir through the refrigerant passage and the second on-off valve. The temperature of the compressor is increased by reducing the amount of refrigerant that is introduced and stored here and circulated within the refrigerant circulation circuit.

After the temperature of the compressor rises to a predetermined temperature, a defrosting operation is performed by opening the throttling mechanism, the first on-off valve, and the second on-off valve, and the high-temperature, high-pressure refrigerant gas discharged from the compressor is passed through the bypass passage. By flowing, the liquid refrigerant in the refrigerant reservoir is heated. As a result, the liquid refrigerant in the refrigerant reservoir returns to the refrigerant circulation circuit through the refrigerant passage and the second on-off valve, and thereafter circulates within the refrigerant circulation circuit.

(Embodiment) An embodiment of the present invention is shown in FIGS. 1 and 2. As shown in FIG. 1, one end is connected to the discharge pipe 8 of the compressor 1, and the other end is connected to the throttle mechanism 4 and the outdoor heat exchanger 5.
A refrigerant reservoir 9 is provided to exchange heat with the bypass circuit 6 connected to the refrigerant circuit between the indoor heat exchanger 3 and the throttling mechanism 4 via the refrigerant passage 10.
connected to the refrigerant circuit between the A second on-off valve 11 is interposed in this refrigerant passage 10 and is opened during defrosting operation and during heating operation before the start of defrosting. A first on-off valve 7 is interposed in the bypass circuit 6 .

This heat pump type air conditioner is equipped with a control device (not shown), and according to commands from this control device, the first on-off valve 7 and the second on-off valve 11 are closed during heating/cooling operation, and when frost formation is detected during heating/heating operation. A heating operation is performed by opening the second on-off valve 11, and after the temperature of the compressor 1 rises to a predetermined temperature, a defrosting operation is performed by opening the throttling mechanism 4, the first on-off valve 7, and the second on-off valve 11. . The rest of the structure is the same as the conventional one shown in FIG. 3, and corresponding members are given the same reference numerals.

Thus, during cooling operation, the first on-off valve 7 and the second on-off valve 11 are closed. Then, compressor 1
The high-temperature, high-pressure refrigerant gas discharged from the refrigerant gas enters the outdoor heat exchanger 5 through the discharge pipe 8 and the four-way valve 2, as shown by the solid arrow, where it condenses and liquefies by dissipating heat to the outside air. It becomes a refrigerant liquid. This refrigerant liquid enters the throttle mechanism 4, where it is throttled and expands adiabatically to become a gas-liquid two-phase at low temperature and low pressure.
Next, this gas-liquid two-phase refrigerant enters the indoor heat exchanger 3, where it evaporates by cooling the indoor air and becomes a low-temperature, low-pressure refrigerant gas. and,
The refrigerant gas returns to the compressor 1 via the four-way valve 2, and the above process is then repeated.

During heating operation, the first on-off valve 7 and the second on-off valve 1
1 is closed, and the four-way valve 2 is switched as indicated by the dashed arrow. Therefore, the refrigerant discharged from the compressor 1 flows through the discharge pipe 8, the four-way valve 2, and the four-way valve 2 as shown by the broken line arrow.
indoor heat exchanger 3, throttle mechanism 4, outdoor heat exchanger 5,
It passes through the four-way valve 2 in this order and returns to the compressor 1, and thereafter,
Repeat the above.

When frost formation on the outdoor heat exchanger 5 is detected by continuing the heating operation, the heating operation is performed. During the heating operation, the four-way valve 2 occupies the switching position shown by the broken line as in the heating operation, and the first on-off valve 7 is closed, but the second on-off valve 11 is opened. Then,
A part of the liquid refrigerant flowing out of the indoor heat exchanger 3 passes through the refrigerant passage 10 and the on-off valve 11, enters the refrigerant liquid reservoir 9, and accumulates there due to the temperature difference with the liquid refrigerant after flowing through the throttling mechanism 4. As a result, the amount of refrigerant circulating in the circulation circuit decreases, and the temperature of the compressor 1 increases.
After the temperature of the compressor 1 rises to a predetermined temperature, the defrosting operation begins.

During defrosting operation, the four-way valve 2 occupies the switching position shown by the broken line, as in heating operation and during heating operation.
The first on-off valve 7 and the second on-off valve 11 are opened, and at the same time, the throttle mechanism 4 is fully opened. As a result, most of the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 enters the outdoor heat exchanger 5 through the discharge pipe 8, the bypass circuit 6, and the first on-off valve 7, and melts the frost that has adhered thereto. It is condensed and liquefied by When high-temperature, high-pressure refrigerant gas flows through the bypass circuit 6, it heats the liquid refrigerant in the refrigerant reservoir 9 that exchanges heat with the bypass circuit 6. The amount of refrigerant that goes out into the circulation circuit via the second on-off valve 11 and circulates through the refrigerant circuit increases. On the other hand, the remainder of the refrigerant gas discharged from the compressor 1 is transferred to the four-way valve 2, the indoor heat exchanger 3, and the fully opened throttle mechanism 4.
It then enters the outdoor heat exchanger 5, where it is condensed and liquefied. Then, it joins with the previously branched refrigerant, returns to the compressor 1 via the four-way valve 2, and repeats the above process.

FIG. 2 shows a flowchart showing the control procedure for this air conditioner, and as shown in FIG. It is judged by
If so, a heating operation is performed in step 3. Thereafter, in step 4, it is determined whether the temperature of the compressor 1 has increased, and if so, a defrosting operation is performed in step 5. Next, in step 6, it is determined whether or not defrosting has been completed, and if so, the process returns to step 1 and heating operation is started, but if not, the process returns to step 5 and defrosting operation is started. Continued. If it is determined in step 2 that frost has not formed, the process returns to step 1 and the heating operation is continued. Also, step 4
If it is determined that the temperature of the compressor 1 has not increased, the process returns to step 3 and the heating operation is continued.

(Effects of the invention) In the present invention, when frost formation on the outdoor heat exchanger is detected during heating operation, the second on-off valve is opened to perform heating operation to accumulate liquid refrigerant in the refrigerant reservoir. A defrosting operation in which the amount of refrigerant circulating in the circulation circuit is reduced to increase the temperature of the compressor, and after the temperature of the compressor rises to a predetermined temperature, the throttling mechanism, the first on-off valve, and the second on-off valve are opened. During heating operation, the liquid refrigerant accumulated in the refrigerant reservoir is returned to the refrigerant circulation circuit to increase the amount of refrigerant circulation, so the time required for defrosting is greatly shortened, and the heating feeling is reduced. It can be significantly improved.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention,
FIG. 1 is a refrigerant system diagram, and FIG. 2 is a flowchart showing control procedures. FIG. 3 is a refrigerant system diagram of a conventional heat pump type air conditioner. Compressor...1, Four-way valve...2, Indoor heat exchanger...
...3, Throttle mechanism...4, Outdoor heat exchanger...5, Discharge pipe...8, Bypass circuit...6, First on-off valve...
…7, Refrigerant reservoir…9, Refrigerant passage…10, Second
Open/close valve...11.

Claims (1)

[Scope of utility model registration request] A refrigerant circulation circuit is composed of a compressor, a four-way valve, an indoor heat exchanger, a throttle mechanism, and an outdoor heat exchanger, and one end is a discharge pipe of the compressor and the other end is a refrigerant circuit between the throttle mechanism and the outdoor heat exchanger. In a heat pump type air conditioner in which a first on-off valve is provided in a bypass circuit connected to the bypass circuit, a refrigerant reservoir is provided to exchange heat with the bypass circuit, and the refrigerant reservoir is passed through a refrigerant passage having a second on-off valve. Connected to the refrigerant circuit between the indoor heat exchanger and the throttling mechanism, the first on-off valve and the second on-off valve are closed during heating and cooling operation, and the second on-off valve is opened when frost formation is detected during heating operation. Heat pump type air, characterized in that it is equipped with a control device that performs a defrosting operation that performs a heating operation and opens a throttling mechanism, a first on-off valve, and a second on-off valve after the temperature of the compressor rises to a predetermined temperature. harmonizer.