JP3019747B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus used for an air conditioner or the like.

[0002]

2. Description of the Related Art Conventionally, this type of refrigeration system is disclosed in
As known from Japanese Patent No. 225852, during cooling, the air flow rate of an outdoor fan attached to an outdoor heat exchanger serving as a condenser is controlled based on the outside air temperature so that the high pressure of the refrigeration system can be appropriately maintained. ing. That is, at the time of cooling under conditions where the outside air temperature is relatively low, the air flow rate of the outdoor fan is made lower than the high air flow rate of the standard time, and the heat exchange amount in the outdoor heat exchanger is set to an appropriate value corresponding to the low outdoor air. It prevents the pressure from dropping excessively so that proper operation can be continued.

[0003]

However, it is not appropriate to perform the above air flow control from the beginning of the start of the cooling operation for the following reasons.

[0004] That is, at the beginning of the startup, the compressor rotor, which constitutes the internal components of the compressor, reaches a relatively high temperature relatively early with the rise of the compressed gas temperature, that is, the discharge gas temperature, but forms the outer frame of the compressor. Since the casing is exposed to the outside air, its temperature rise is slow, and a large temperature difference is generated between the compressor rotor and an outer frame member surrounding the compressor rotor as compared with a normal state. Despite this tendency, if the air flow of the outdoor fan is adjusted to a low air flow due to the low outside air, the temperature rise of the discharge gas is further promoted, and the compressor is strongly affected by this temperature. The temperature rise of the rotor is further promoted, and an excessively large temperature difference is generated between the compressor rotor and its outer frame members. Here, the gap between the compressor rotor and its outer frame member is
The value is set to a very narrow value to prevent the performance of the compressed gas from leaking to the low pressure side and causing a loss in performance. Therefore, the thermal expansion of the compressor rotor becomes excessively larger than the thermal expansion of the outer frame member, and a contact occurs between the compressor rotor and the outer frame member, causing a problem of seizure.

According to the present invention, there is provided a refrigerating apparatus in which the air flow rate of an outdoor fan attached to an outdoor heat exchanger serving as a condenser during cooling is controlled based on the outside air temperature so that the high pressure of the refrigerating apparatus can be maintained at an appropriate value. To provide a refrigeration system that can improve reliability by eliminating the adverse effect of control at the beginning of starting, that is, the problem of the occurrence of a seizure accident in the compressor, in such a refrigeration system. Is its main purpose.

[0006]

Therefore, in order to achieve the above-mentioned main object, the invention according to claim 1 is, as shown in FIG. 1, provided on the discharge side of the compressor 1 as an air-cooled type which becomes a condenser during cooling. In the refrigerating apparatus in which the outdoor heat exchanger 2 is connected and the air flow of the outdoor fan 20 attached to the outdoor heat exchanger 2 is controlled based on the outside air temperature at the time of cooling, the operation is started at the beginning of the start of the cooling operation. A forced air volume adjusting means 7 for forcibly operating the outdoor fan 20 at a high air volume during the transition period is provided, and compression during the operation start-up transition period is performed.
Excess liquid to the compressor 1 for a predetermined period at the beginning of the operation of the compressor 1
Suppress return and keep compressor 1 low capacity lower than rated capacity
The configuration is such that the combined control means operating at is provided .

According to a second aspect of the present invention, in accordance with the first aspect of the present invention, the air volume adjustment by the forced air volume adjusting means 7 is canceled with a simple configuration.
A timer TM for releasing the air volume adjustment by the forced air volume adjusting means 7 by measuring a predetermined time is provided.

[0008] The invention according to claim 3 is based on an appropriate judgment.
Release the compulsory high air volume control,
As shown in FIG. 3, the compressor 1
Air-cooled outdoor heat exchange that becomes a condenser during cooling on the discharge side of
Heater 2 is connected and outdoor heat exchange is performed based on the outside air temperature during cooling.
The outdoor fan 20 attached to the vessel 2 is controlled in air volume.
In the refrigerating system,
During the transitional period of operation start-up, the outdoor fan 20
When the forced air volume adjusting means 7 for operating the air volume is provided,
Further, a configuration is provided in which there is provided a release means 8 based on discharge gas determination for releasing the air volume adjustment by the forced air volume adjustment means 7 based on a change in the temperature or pressure of the discharge gas of the compressor 1.

[0009]

According to the first aspect of the present invention, regardless of the outside air temperature,
That is, even during low outdoor air, the outdoor fan 20 is forcibly operated at a high air flow by the forced air flow adjusting means 7 during the operation start-up transition period at the beginning of the start of the cooling operation.
In addition, during the operation start-up transition period, the operation of the compressor 1 is performed.
During a predetermined period at the beginning of the rotation, the compressor 1 suppresses excessive liquid return.
It is operated at a low capacity while controlling. For this reason, it is possible to suppress a rise in the temperature of the discharge gas in the initial stage of startup, and to suppress a rise in the temperature of the compressor rotor that is an internal component of the compressor 1 that is strongly affected by the temperature of the discharge gas. Therefore, the temperature difference between the compressor rotor and the outer frame member surrounding the compressor rotor can be reduced, and the seizure accident caused by the difference in thermal expansion can be prevented. At the same time, the hydraulic pressure caused by the liquid back
Excessive pressure and temperature rise due to compression can be suppressed, and the compressor 1
Can be effectively prevented. In particular, it is effective for a rotary compressor that requires a very small gap between the compressor rotor and its outer frame. After the elapse of the operation start-up transition period, the outdoor fan 20 is controlled in air volume based on the outside air temperature, and in low outdoor air, the air volume is controlled to a low air volume. It is possible to perform proper operation.

According to the second aspect of the present invention, the adjustment of the air volume by the forced air volume adjusting means 7 is canceled after a predetermined time is counted by the timer TM. Since the forced air volume adjustment is uniformly canceled by the timer TM, the timing of canceling the forced air volume adjustment is not always optimal at all times depending on the outside air temperature, the initial temperature of the compressor 1, and the like. Since the control is switched by the time measurement, the configuration can be simplified.

According to the third aspect of the present invention, the forced air flow rate adjusting means 7 based on a change in the temperature or pressure of the gas discharged from the compressor 1.
The air volume adjustment by is released. At the beginning of the start of the operation, the temperature rise of the discharge gas is suppressed by the forced air volume adjusting means 7. However, the discharge gas temperature or the pressure follows an increasing tendency with the lapse of time from the start of the start, and gradually changes when approaching the steady operation. Eventually, it will eventually reach a predetermined value. This change in the discharge gas temperature or pressure has a temporal difference depending on various conditions such as the outside air temperature and the initial temperature of the compressor 1, but the change tendency is the same. Therefore, it is possible to know whether or not the operation is close to the steady operation based on the change in the discharge gas temperature or the pressure, and the air volume adjustment by the forced air volume adjusting means 7 is released based on this change. Although the configuration is more complicated than the switching of the control, the control can be more appropriately switched according to various conditions such as the outside air temperature and the initial temperature of the compressor 1.

[0012]

FIG. 1 shows a heat pump type refrigerating apparatus capable of cooling and heating. From a discharge port 11 to a suction port 12 of a compressor 1, a discharge pipe 61 and a first four-way switching valve 4 are provided.
Fixed port 41, first switching port 4 of four-way switching valve 4
3, gas pipe 62, outdoor heat exchanger 2, which becomes a condenser during cooling and becomes an evaporator during heating, liquid pipe 63, expansion mechanism 3, liquid pipe 6
4. an indoor heat exchanger 5, which serves as an evaporator during cooling and a condenser during heating, a gas pipe 65, a second switching port 44 of the four-way switching valve 4, a second fixed port 42 of the four-way switching valve 4, a suction pipe 6
6 are sequentially connected.

The compressor 1 is provided with a compressor rotor 14 driven by a compressor motor CM inside an outer casing 13, and is defined between the rotor 14 and a stationary member surrounding the casing 13 on the casing 13 side. The refrigerant is compressed in the compression chamber. In addition, a bypass type capacity control mechanism for bypassing the gas in the middle of the compression stroke to the suction side is provided, and its load% can be changed to 12% and 40% of the low capacity and 100% of the rated capacity, respectively. . The capacity control mechanism may be of a bypass type or of a rotational speed changing type using an inverter or the like. The type of the compressor 1 is, for example, a rotary type using a rolling piston for the compressor rotor 14.

The outdoor heat exchanger 2 is an air-cooled type.
An outdoor fan 20 is provided. This outdoor fan 20
Are driven by a fan motor FM, and the number of revolutions is switched between high speed and low speed by pole number conversion or the like so that the air volume can be changed. In order to change the air volume of the outdoor fan 20, in addition to changing the rotation speed of the fan motor FM,
May be configured with a plurality of fans, and the air volume may be changed by changing the number of fans operated.

In this way, during cooling, the refrigerant is circulated as shown by the solid arrow in FIG. 1, and the outdoor heat exchanger 2 is connected to the condenser.
The indoor heat exchanger 5 is used as an evaporator to cool the room. On the other hand, at the time of heating, the four-way switching valve 4 switches the communication relationship of the ports as shown by the dotted line, thereby circulating the refrigerant as shown by the dotted arrow, turning the indoor heat exchanger 5 into a condenser, and the outdoor heat exchanger. 2 is an evaporator to warm the room.

The compressor motor CM, the fan motor FM, and the like are controlled by the controller 100. During a cooling operation and during a steady state after a considerable time has elapsed since the start of the compressor motor CM, the outside air temperature is controlled. Detector 101
The air flow of the outdoor fan 20 is controlled on the basis of the outside air temperature detected in step (1). That is, for example, when the outside air temperature exceeds 20 degrees Celsius, the air volume is controlled to be high when the outside air temperature is higher than 20 degrees Celsius, and when the outside air temperature is 20 degrees Celsius or lower, the air volume is controlled to be low. still,
During heating, the outdoor fan 20 has a uniform high air volume.

In the above configuration, the controller 100
Further, there is provided a forced air volume adjusting means 7 for forcibly operating the outdoor fan 20 at a high air volume during an operation startup transition period at the beginning of the start of the cooling operation. The release of the air volume adjustment by the forced air volume adjusting means 7 is performed by, for example, time-up of a timer TM that measures a predetermined time of 7 minutes.

The control from the beginning of the cooling operation is performed according to the flowchart shown in FIG. That is, immediately after the start of the cooling operation, the air volume of the outdoor fan 20 is forcibly increased to the high air volume H.
(Step a), the outdoor fan 20 is operated at a high air flow (Step b), and then, after a time delay of, for example, about 5 seconds, the compressor 1 is driven (Step c). Until seven minutes, which is the time period of the timer TM, has elapsed, the outdoor fan 20 continues to operate at a high air flow (step d), thereby suppressing an increase in the discharge gas temperature of the compressor 1 and increasing the compressor rotor 14. The temperature difference between the stationary member and the surrounding stationary member on the casing 13 side is reduced, and the difference in thermal expansion between the two is reduced to prevent the occurrence of a burn-in accident.

After seven minutes have passed and the timer TM has timed out, the routine shifts to fan control in a steady state based on the outside air temperature detected by the outside air temperature detector 101 (step e). Is less than T degrees, for example, 2 degrees Celsius
When the outside air does not exceed 0 degrees, the air volume is set to low air volume L (step f), and when the outside air exceeds 20 degrees, the air volume is set to high air volume H (step g). In this way, after the shift to the steady operation, in the case of low outside air, the flow rate of the outdoor fan 20 is suppressed to a low level, so that an extreme decrease in the discharge gas pressure, that is, the high pressure, can be suppressed, and the proper operation can be continued.

By the way, the actual operation from the start is as follows:
The control of the capacity of the compressor 1 is also performed in combination, as shown in FIG. That is, the compressor 1 is first driven at 12% of the minimum capacity 5 seconds after the start of the start, that is, 5 seconds after the start of the outdoor fan 20. This is because the compression power is reduced, and the starting current of the compressor motor CM is reduced so that the smooth operation can be started. Next, for 2 to 5 minutes after the start of the operation, the operating capacity is loaded to 40%. Start 5
A period before the elapse of 5 minutes from the second, that is, a period in which the compressor 1 is operated at 12% and 40% is a so-called pump-down operation period for preventing liquid back, and the opening degree of the expansion mechanism 3 is reduced. Alternatively, the compressor 1 is closed to prevent a large amount of liquid from returning to the compressor 1 abruptly, so that the compressor 1 is prevented from being damaged. Five minutes after the start of the operation, the load is 100% of the rated capacity. However, this is generally due to the large load in the room at the beginning of the operation and the large load in the room. However, when the indoor load is small, the operation may naturally continue at 40%.

During the forced air volume adjustment period by the forced air volume adjustment means 7, that is, 7 minutes, which is the time period measured by the timer TM,
The above-mentioned capacity control period for the pump down at the start of the start-up is covered for 5 minutes.
Discharge gas temperature T2 after loading to 0% load
During this seven-minute period, the outdoor fan 20 is operated at a high air flow to operate, thereby increasing the temperature of the discharge gas temperature T2 and thus the compressor. A rise in the temperature of the rotor 14 can be suppressed, and the temperature difference from the temperature T1 of the stationary member on the casing 13 side, which is the outer frame, can be prevented from becoming excessively large, and a seizure accident caused by a difference in thermal expansion can be avoided. It is.

As shown in FIG. 1, the compressor 1 has a discharge gas temperature detector 102 for evaluating the temperature of a compressor rotor 14 as an internal component thereof, and a stationary casing 13 side surrounding the compressor rotor 14. An external temperature detector 103 for detecting the temperature of the member is provided.
Is input to the controller 100, and when the temperature difference between the two reaches 30 degrees, the operation is abnormally stopped at any time. As described above, at the beginning of startup, the excessive air temperature between the compressor rotor 14 and the stationary member surrounding the compressor rotor 14 which may occur if the air volume is reduced by the forced air volume adjusting means 7 at low outside air as in the steady state. The difference can be reduced, and an abnormal stop is rare.However, in the case of an abnormality that cannot be avoided even by forced air flow control, the operation can be stopped before the accident occurs,
Further safety can be achieved. In addition, even during a steady state, the temperature between the two members where actual burn-in can occur is always monitored and stopped in the event of an abnormality, so that reliable safety is achieved.

In the above, the control period of the forced air volume control means 7 is fixed to 7 minutes, which is the time period of the timer TM. However, as shown in FIG. The discharge gas temperature T2 gradually rises and tends to settle to a predetermined value. Therefore, instead of the timer TM, as shown in FIG. 4, the discharge gas temperature or the discharge gas pressure following the substantially same change tendency as shown in FIG. May be canceled based on the change in the air volume. That is, there is provided a releasing means 8 based on a discharge gas determination for releasing the air volume adjustment by the forced air volume adjusting means 7 based on a change in the discharge gas temperature or the pressure, and the releasing means 8 performs discharge as shown by a point P in FIG. Control may be switched by detecting near the peak point of the gas temperature T2. In this case, it is necessary to monitor the change in the discharge gas temperature or the pressure on the controller 100, but the control can be appropriately switched according to the difference between the outside air temperature and the initial temperature of the compressor 1.

[0024]

According to the first aspect of the present invention, the compressor 1
Low volume while suppressing excessive liquid return at the beginning of operation
In combination with pump down by operation, the outdoor fan 20
Because the air volume is high, it can be used for liquid compression due to liquid back.
Excessive pressure and temperature rise due to
Above the temperature of the discharged gas due to the inappropriate air volume of the fan 20
Minimizes the temperature difference between the compressor rotor and the outer member due to rising
Thus, damage to the compressor 1 can be effectively prevented.

According to the second aspect of the present invention, the timer TM
Since the control is switched by the time measurement, the configuration can be simplified.

According to the third aspect of the present invention, the adjustment of the air volume by the forced air volume adjusting means 7 is canceled based on the change in the temperature or pressure of the discharged gas, so that various conditions such as the outside air temperature and the initial temperature of the compressor 1 can be adjusted. Accordingly, more appropriate control switching can be performed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a refrigeration apparatus of the present invention.

FIG. 2 is a flowchart of the control.

FIG. 3 is a time chart of the control.

FIG. 4 is a configuration diagram of a main part of another embodiment.

[Explanation of symbols]

1; compressor; 2; outdoor heat exchanger; 20; outdoor fan;
7; forced air volume adjusting means, TM; timer, 8;

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-225852 (JP, A) JP-A-59-93160 (JP, A) JP-A-3-175230 (JP, A) JP-A-6-205 323647 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 1/00 351 F25B 1/00 341

Claims (3)

(57) [Claims] An air-cooled outdoor heat exchanger (2), which is a condenser during cooling, is connected to the discharge side of the compressor (1), and the outdoor heat exchanger (2) is based on the outside air temperature during cooling. In the refrigeration system in which the outdoor fan (20) attached to the air conditioner is controlled in air volume, forced air volume control in which the outdoor fan (20) is forcibly operated at a high air volume during a start-up transition period at the beginning of the start of cooling operation. Means (7) ,
Operation of the compressor (1) during the operation start-up transition period
Excess liquid return to compressor (1) for a predetermined period at the beginning
Suppress and operate the compressor (1) at a low capacity lower than the rated capacity
A refrigeration apparatus comprising a combined control unit for operating . 2. The refrigerating apparatus according to claim 1, further comprising a timer (TM) for releasing the air volume adjustment by the forced air volume adjusting means (7) by measuring a predetermined time. 3. A condenser on the discharge side of the compressor (1) during cooling.
Air-cooled outdoor heat exchanger (2)
At times, it is attached to the outdoor heat exchanger (2) based on the outside air temperature
A refrigeration system that controls the air flow of the outdoor fan (20)
At the beginning of the start of cooling operation
During the transition period, the outdoor fan (20) is forcibly operated at a high air flow.
A forced air volume adjusting means (7) for turning is provided,
Based on the change in the temperature or pressure of the gas discharged from the compressor (1)
A spout for canceling the air volume adjustment by the forced air volume adjusting means (7)
It is characterized in that it comprises a release means (8) for determining outgassing.
Refrigeration equipment .