JP2001116374A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start a freezing preventing operation after an indoor side heat exchanger is actually frosted. SOLUTION: In the refrigerator comprising a compressor 1, an outdoor side heat exchanger 3 operated as a condenser when cooled or operated as an evaporator when heated, a pressure reducing mechanism 4, and an indoor side heat exchanger 5 operated as an evaporator when cooled or operated as a condenser when heated, when a mean cooling integrated capability Qr when cooled is lowered, a control means (controller 17) for starting a freezing preventing operation for stopping an operation of the compressor 1 is attached, and when the exchanger 5 is frosted to lower the capability Qr, the freezing preventing operation for stopping the compressor 1 is started.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus, and more particularly, to an antifreeze operation control during a cooling operation in a refrigerating apparatus.

[0002]

2. Description of the Related Art A compressor, an outdoor heat exchanger acting as a condenser during a cooling operation and acting as an evaporator during a heating operation, a pressure reducing mechanism, acting as an evaporator during a cooling operation and acting as a condenser during a heating operation A refrigeration system having an indoor heat exchanger is well known.

In this refrigerating apparatus, it is necessary to perform an antifreezing operation because the capacity is reduced when the indoor heat exchanger is frosted during the cooling operation.

[0004] In the conventional anti-freezing operation, the state in which the temperature of the indoor heat exchanger is lower than -5 ° C continues for one minute or more, or the state in which the temperature of the indoor heat exchanger is lower than -1 ° C. When the accumulated time becomes 40 minutes or more, the operation is started by stopping the operation of the compressor.

[0005]

However, as described above, when the determination of the freeze prevention operation control is determined based on the temperature and time of the indoor heat exchanger, frost is actually formed on the indoor heat exchanger. However, there is a possibility that the anti-freezing operation may be started even though it is not performed.

The present invention has been made in view of the above points, and has as its object to enable the freezing prevention operation to be started after frost has actually formed on the indoor heat exchanger. .

[0007]

According to the first aspect of the present invention, as a means for solving the above-mentioned problems, the compressor 1 has an outdoor heat source that functions as a condenser during a cooling operation and as an evaporator during a heating operation. In the refrigeration system including the exchanger 3, the pressure reducing mechanism 4, and the indoor heat exchanger 5 that functions as an evaporator during the cooling operation and also functions as the condenser during the heating operation, the average cooling integration capacity Qr during the cooling operation is reduced. In this case, a control means for starting an anti-freezing operation for stopping the operation of the compressor 1 is additionally provided.

[0008] With the above-described configuration, when the indoor heat exchanger 5 is frosted and the average cooling integration capacity Qr is reduced, the anti-freezing operation for stopping the operation of the compressor 1 is started. . Therefore, the actual occurrence of frost on the indoor heat exchanger 5 corresponds to the anti-freezing operation control,
The cooling operation ratio will increase.

As in the invention of claim 2, claim 1
In the refrigeration apparatus described above, if the control means operates when the decrease in the average cooling integral capacity Qr continues for a predetermined time, the decrease in the cooling capacity is caused by a factor other than frost formation on the indoor heat exchanger 5. It is possible to exclude a suddenly generated one, and it is possible to perform more accurate antifreezing operation.

[0010] As in the invention of claim 3, claim 1
In the refrigerating apparatus according to any one of (2) and (3), when the average cooling integration capacity Qr is determined based on a temperature difference between the temperature Tg of the outdoor heat exchanger 5 and the outdoor air temperature Ta, The average cooling integration capability Qr can be determined only by the dry-bulb temperature, and the calculation process is simplified.

[0011]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, the refrigerating apparatus includes a compressor 1, a four-way switching valve 2, an outdoor heat exchanger 3 that functions as a condenser during a cooling operation and as an evaporator during a heating operation, An electronic expansion valve 4 acting as a mechanism, an indoor heat exchanger 5 acting as an evaporator during a cooling operation and acting as a condenser during a heating operation, and is configured by a switching operation of the four-way switching valve 2. The refrigerant can be reversibly circulated. Reference numeral 6 denotes a subcooling heat exchanger attached to the indoor side heat exchanger 3, reference numeral 7 denotes a receiver, and reference numeral 8 denotes a refrigerant flow switching mechanism.

The refrigerant flow switching mechanism 8 is composed of four check valves 9 to 12, and the refrigerant from the outdoor heat exchanger 3 or the indoor heat exchanger 5 is constantly transmitted from the receiver 7 to the electronic expansion valve 4. It is to be controlled to flow to

Reference numeral 13 denotes a bypass which communicates the gas phase of the receiver 7 with the downstream side of the electronic expansion valve 4. The bypass 13 is provided with an electromagnetic valve 14 which is opened when the operation is stopped. Has been established.

The compressor 1, the four-way switching valve 2, the outdoor heat exchanger 3, the electronic expansion valve 4, the receiver 7, and the refrigerant flow switching mechanism 8 constitute an outdoor unit A, and the indoor heat exchanger 5 is an indoor unit. Unit B is configured.

Reference numeral 15 denotes an outside air temperature sensor for detecting an outside air temperature Ta, and reference numeral 16 denotes an outdoor heat exchange temperature Tg of the outdoor heat exchanger 3.
Outdoor heat exchange sensor that detects

Reference numeral 17 denotes a controller acting as control means. The controller 17 receives temperature information from the outside air temperature sensor 15 and the outdoor heat exchange sensor 16 (ie, the outside air temperature Ta and the outdoor heat exchange temperature Tg). Is entered. The controller 17 performs a calculation process such as the cooling integration capacity Qr, and outputs a control signal to the compressor 1 based on the calculation result.

Next, with reference to the flowchart of FIG. 2, a description will be given of the freezing prevention operation control during the cooling operation of the refrigeration apparatus according to the present embodiment.

When the cooling operation is started, in step S, temperature information from the outside air temperature sensor 15 and the outdoor heat exchange sensor 16 (that is, the outside air temperature Ta and the outdoor heat exchange temperature Tg) is input to the controller 17, and step S2 is performed. In the above, based on the outside air temperature Ta and the outdoor heat exchange temperature Tg, the current average cooling integration capacity Qr is calculated by the following equation.

Qr = dQ / t = Σ (Tg−Ta) / (t
(R + 10 × 60) where, tR: cooling operation time and the current average cooling integral capacity Qr calculated in step S3 and the maximum value Qrmax of the average cooling integral capacity
When it is determined here that Qr> Qrmax (in other words, when it is determined that the average cooling integration capacity Qr is increased), the current average cooling integration capacity Qr is set to the maximum value in step S4. Replaced by Qrmax,
In step S5, the integration capability reduction timer Td is reset, and the process returns to step S1.

If it is determined in step S3 that Qr.ltoreq.Qrmax, it indicates that the average cooling integral capacity Qr is decreasing. Therefore, in step S6, the count of the integral capacity decreasing timer Td is started, and step S7 is started.
When it is determined that the integration capability reduction timer Td has counted up for 100 seconds in step, the operation of the compressor 1 is stopped in step S8, and the antifreezing operation is started. Thereafter, in step S9, the average cooling integration capacity Qr and the maximum value Qrmax of the average cooling integration capacity are returned. In step S5, the integration capacity reduction timer Td is reset, and the processing returns to step S1.

The above control is as shown in the time chart of FIG. That is, during the cooling operation, when the average cooling integration capacity Qr continues to decrease for 100 seconds, the antifreezing operation for stopping the operation of the compressor 1 is started.

Accordingly, the actual occurrence of frost on the indoor heat exchanger 5 and the anti-freezing operation control correspond, and the cooling operation ratio is improved. In addition, it is possible to exclude a sudden decrease in the cooling capacity caused by a cause other than the frosting of the indoor heat exchanger 5, and it is possible to perform more accurate antifreezing operation.

Further, since the average cooling integration capacity Qr is determined based on the temperature difference between the temperature Tg of the outdoor heat exchanger 5 and the outdoor air temperature Ta, the average cooling integration capacity is determined only by the dry bulb temperature. Qr can be determined, and the arithmetic processing is simplified.

[0025]

According to the first aspect of the present invention, the compressor 1, the outdoor heat exchanger 3, which functions as a condenser during the cooling operation and functions as the evaporator during the heating operation, the pressure reducing mechanism 4, and evaporates during the cooling operation In the refrigerating apparatus provided with the indoor heat exchanger 5 acting as a condenser and acting as a condenser during the heating operation, when the average cooling integration capacity Qr during the cooling operation is reduced, the operation of the compressor 1 is stopped. A control means for starting the preventive operation is provided so that when the frost is formed on the indoor heat exchanger 5 and the average cooling integration capacity Qr is reduced, the freeze prevention operation for stopping the operation of the compressor 1 is started. Therefore, the actual occurrence of frost on the indoor-side heat exchanger 5 corresponds to the anti-freezing operation control, and the cooling operation ratio is increased, and the cooling integration capability is improved.

As in the invention of claim 2, claim 1
In the refrigeration apparatus described above, if the control means operates when the decrease in the average cooling integral capacity Qr continues for a predetermined time, the decrease in the cooling capacity is caused by a factor other than frost formation on the indoor heat exchanger 5. It is possible to exclude a suddenly generated one, and it is possible to perform more accurate antifreezing operation.

As in the invention of claim 3, claim 1
In the refrigerating apparatus according to any one of (2) and (3), when the average cooling integration capacity Qr is determined based on a temperature difference between the temperature Tg of the outdoor heat exchanger 5 and the outdoor air temperature Ta, The average cooling integration capability Qr can be determined only by the dry-bulb temperature, and the calculation process is simplified.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing details of antifreeze operation control in the refrigeration apparatus according to the embodiment of the present invention.

FIG. 3 is a time chart showing contents of antifreeze operation control in the refrigeration apparatus according to the embodiment of the present invention.

[Explanation of symbols]

1 is a compressor, 3 is an outdoor heat exchanger, 4 is a pressure reducing mechanism (electronic expansion valve), 5 is an indoor heat exchanger, 15 is an outside air temperature sensor, 16 is an outdoor heat exchange sensor, and 17 is a control means (controller). ).

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tatsuo Fujiwara 1304 Kanaokacho, Sakai-shi, Osaka Daikin Industries, Ltd. Sakai Seisakusho Kanaoka Plant F-term (reference) 3L060 AA08 CC03 CC04 CC18 DD01 EE02

Claims (3)

[Claims] 1. A compressor (1), an outdoor heat exchanger (3) acting as a condenser during a cooling operation and acting as an evaporator during a heating operation, a pressure reducing mechanism (4), acting as an evaporator during a cooling operation. And a refrigeration system having an indoor heat exchanger (5) acting as a condenser during a heating operation, wherein when the average cooling integration capacity (Qr) during the cooling operation decreases, the compressor (1) A refrigeration system, further comprising control means for starting an anti-freezing operation for stopping the operation. 2. The method according to claim 1, wherein the control means includes an average cooling integration capacity (Q
2. The refrigeration system according to claim 1, wherein the refrigeration apparatus operates when the reduction of r) continues for a predetermined time. 3. The method according to claim 1, wherein the average cooling integral capacity (Qr) is determined based on a temperature difference between a temperature (Tg) of the outdoor heat exchanger (5) and an outdoor air temperature (Ta). The refrigeration apparatus according to claim 1, wherein the refrigeration apparatus is characterized in that: