JPH02248674A - Refrigerator - Google Patents

Abstract

PURPOSE:To reduce the temperature fluctuation, etc., against the refrigerated load at the time of judging the low ability operation with a low ability operation judging means by providing a back-up means for stopping a compressor under operation when the abnormality of the compressor under operation is detected and for operating a compressor under standing. CONSTITUTION:Te operated unit number of compressors 1, 2 is controlled on the basis of a detected result of a load detecting means 300, and an ability control means 400 for adjusting the ability is comprised, and the operated unit control is performed by the ability control means 400 to perform the low ability operation. Wen the operated unit control is performed by the ability control means 400 to perform the low ability operation, a low ability operation judging means 500 for judging the low ability operation that stops one of the compressors 1, 2 and operates only the other one is provided. At the time of judging the low ability operation with the judging means 500, when the abnormality of the compressor (1 or 2) under operation is detected by the detecting means (100 or 200), a back-up means 600 stops the compressor under operation and operates the compressor under standing. The temperature adjusting control against the load is thereby continued.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Application The present invention relates to a refrigeration system that is equipped with a plurality of compressors and whose capacity is adjusted by controlling the number of compressors in operation.

(Conventional technology) Conventionally, when a system is equipped with multiple compressors and there is surplus refrigeration capacity due to a decrease in refrigeration load, the number of operating compressors is reduced to adjust the capacity to match the load. This is known from Japanese Patent Publication No. 63-37885, for example.

(The problem that the invention aims to solve) In a refrigeration system, if some kind of abnormality occurs in the 5IIf, the operation is usually stopped from the viewpoint of protecting the VI equipment.

However, in a refrigeration system equipped with multiple compressors, for example, when only one of two compressors is being operated in response to low capacity, an abnormality may occur and the operating compressor may be Stopping this means stopping the entire device. Therefore, even if the device can be protected, the temperature adjustment for the refrigeration load is interrupted, resulting in a problem that the temperature of the refrigeration load, such as chilled water, deviates from the set value.

Considering the conditions under which the protection device is activated, in addition to common system abnormalities that occur in multiple compressors, such as interruptions in the supply of refrigeration loads such as chilled water, There are abnormalities that occur individually around each compressor, such as an excessive rise in discharge gas temperature. If this individual abnormality occurs in an operating compressor during low capacity operation, it is a good idea to stop the operating compressor, but if the compressor was originally stopped due to low capacity, If there are no abnormalities, you are playing in vain.

Therefore, the present invention provides a refrigeration system that can reduce temperature fluctuations with respect to refrigeration load by operating a stopped compressor instead when the condition for activation of the protection device is an individual abnormality for each compressor. The purpose is to

(Means for solving the problem) In order to achieve the above purpose, a plurality of compressors (1) (2),
A refrigeration system equipped with a capacity control means (400) that adjusts the capacity by controlling the number of compressors (1) and (2) in operation, wherein each compressor (1) and (2) (1)
(2) In addition to providing detection means (100) and (200) for detecting abnormal signals that occur individually in the surroundings, low-capacity operation discriminating means ( 500), and this discriminating means (
500), the operating compressor (
1 or 2) is detected, the operating compressor (1)
Or, it was decided to provide backup means (800) for stopping compressor 2) and operating the stopped compressor (2 or 1).

(Function) During low-capacity operation by controlling the number of units, if an individual abnormality occurs in a compressor in operation, the compressor in operation will be stopped, but the stopped compressor will be operated instead, protecting the equipment. However, it is possible to avoid stopping the entire device, and to continuously perform temperature control for the load.

(Example) Fig. 1 schematically shows an operation control system in a refrigeration HR that is equipped with two compressors, a first compressor (1) and a second compressor (2). A load detector (30
capacity control means (10) that controls the number of operating compressors (1) and (2) and adjusts the capacity based on the detection results of 0);
0), and when performing low capacity operation by controlling the number of compressors (400), that is, when one of the compressors (1) and (2) is stopped and only the other is operated. Low ability driving discrimination means (5) for determining ability driving
00), and detecting means (100) for detecting abnormal signals generated individually in each of the compressors (1) and (2).
) (200), and the low capacity operation determining means (500) is provided.
), and when an abnormality is detected in the operating compressor (1 or 2), the operating compressor (1 or 2) is stopped and the stopped compressor ( 2 or 1) is provided with backup means (600) for operating.

Also, what is shown in Fig. 3 is the first compressor (1) and the second compressor (1).
This figure shows the refrigerant piping system of a refrigeration system equipped with two compressors, the compressor (2), and the discharge pipe (3) of each compressor.
4), an oil recovery device (5) (6) is installed, and the high pressure gas pipes (7) (8) on the outlet side are common to the condenser (8) where the cooling water pipe (90) is installed. and the condenser (
The high pressure liquid pipe (10) on the outlet side of 9) is branched into two directions, and an expansion mechanism (13) (14) such as an electric expansion valve is interposed in each high pressure liquid branch pipe (11) (12). , the low pressure liquid branch pipes (15) and (16) on the outlet side have two refrigerant flow passages,
It is connected to an evaporator (18) having an inlet pipe (17a) and an outlet pipe (17b) for cold water or brine used as a cold heat source for air conditioning, etc., and a low-pressure gas pipe (
1θ) (20) is connected to the suction side of each compressor (1) (2).

Each compressor (1) (2) is powered by an electric motor (Ml).
(M2), and based on the detection result from the load detector (300), when the heat load on the evaporator (18) is large due to the operation of the capacity control means (400), high capacity is achieved by using two units in combination. When operation is performed and the heat load is small, low-capacity operation is performed using only one unit, and this low-capacity operation can be determined by the low-capacity operation discriminating means (500).

Each oil recovery device (5) (6) has an oil tank (5
0) (80), and cooling water pipes (23) (24) are installed in the oil return pipes (21) (22) extending to the low pressure suction side of each compressor (1) (2). Coola (25) (28)
Additionally, oil filters (27) and (28) are installed. Note that (29) and (30) are liquid level gauges.

With the above configuration, for each compressor (1) and (2), the first and second
A detection means (Zoo) (200) is provided. The valley detection means consists of the following:

■ Motor overload switches (58X1) (58X2) that operate by detecting overload conditions such as compressor motor (Ml) (M2) overcurrent or abnormal temperature rise ■Discharge pipes (3) (4)
Discharge gas high humidity switch (260H1) (28DH2) that operates by detecting an abnormal pressure rise in the discharge gas flowing through the exhaust gas pipes (260H1) (28DH2) ■ Activates by detecting an abnormal pressure drop in the suction gas flowing into the low pressure gas pipes (19) (20) Suction pressure pressure switch (83
EL1) (83EL2) ■ Discharge pressure pressure switch (63CH1) (83CH2) that operates by detecting an abnormal pressure rise in the discharge gas in the oil recovery device (6) (θ). High temperature switch (2
8QH1) (28QH2) ■ Oil return pipe (21) (22) that determines the return oil supply amount
A high-low differential pressure switch (θ3HL) that operates by detecting an abnormal decrease in the differential pressure between the
1) (83HL2) ■ Oil filter differential pressure pressure switch (830F1) that operates by detecting an abnormal increase in the differential pressure across the filters (27) (28) due to clogging, etc. ) (630F2)■ Oil recovery device (5
) (8) Oil level switches (33081) (330S2) that are activated by detecting an abnormal rise in the liquid level detected by each liquid level gauge (29) (30) attached to the unit (8) Detection means using the above switches, etc. (100) (200)
The system detects abnormalities that occur individually around each compressor (1) and (2), and when an individual abnormality is detected, it is sufficient to stop only the corresponding compressor. At this point, the introduction tube (1
A brine water cutoff detector 133BEL) that detects water cutoff of brine, etc. introduced into the evaporator (18) via 7a) and a brine appropriate cooling detector (133BEL) that detects excessive cooling of the brine.
The abnormality detected in 288E) commonly occurs in the system regardless of which compressor is being operated, and is different from the case where the operation is stopped uniformly when this common abnormality is detected.

In this way, when only one unit is operating at a low capacity due to the number control by the capacity control means (400), an individual abnormality is detected in the operating compressor (1 or F12) as shown in Fig. 2. and stop the compressor (1 or 2) in operation,
A backup means is provided to operate the stopped compressor (2 or 1).

In FIG. 2, the relay (5TIX) is connected to the detector (
e3BEL, 28Bg), the contact (5T
l) is switched and a common abnormality is detected, the relay (
1-1) Opens each make contact (5TIX-al) (5TIX-a2) interposed in the excitation lines (a) and (b) of (1-2). In addition, the relay (572X) closes the contact (5T) when one of the switches of the first detection means (100) is operated.
2) is switched and the individual abnormality is detected, a degaussing operation opens the make contact (5T2X-at) interposed in the excitation line (a) on the first compressor side, and the second compressor Break contact (572X
-b), and when the contact (5T3) of the relay (573X) is switched by the operation of one of the switches of the second detection means (200) and the individual abnormality is detected, The degaussing operation opens the make contact (573X-al) interposed in the excitation line (b) on the second compressor side, and
This closes the break contact (573X-b) interposed in the excitation line (a) on the first compressor side.

Therefore, in the embodiment shown in FIG. 2, the backup means includes the relays (572X) (
5T3X) and these relays (5T2X) (5T3X)
The contact (572X-at) (5T2
X-b), (5T3X-at) (5T3X-b) are interposed in the excitation lines (a) and (b) of the relays (1-1) and (1-2).

In addition, in Fig. 2, the operation is started by pressing the start switch (
3-1), the relay (4-1) is energized and the make contact (4-1-at) interposed in series with each of the excitation lines (a) and (b) is closed. cormorant. Note that a make contact (4-1-a2) of the relay (4-1) is provided in parallel with the start switch (3-1) for self-holding purposes. In addition, the excitation line of the relay (4-1) has a contact (5TIX-a3) that opens when a common abnormality occurs, and a contact (5T2X-a2) (573X-a) that opens when an individual abnormality occurs.
2) is connected in series/parallel circuit.

The operation is stopped by releasing the self-holding state by turning off the stop switch (5-1) and demagnetizing the relay (4-1).

When one compressor is operated, the selection of the compressor to be operated is done by a ratchet type relay (PR) that alternately switches its contact (PR-c) each time it is excited, so that each compressor is used almost equally. I try to do that. That is, contact (PR-c)
When is in the position shown, the relay (4X1) is energized and the first
A contact (4X1-a) interposed in the excitation line (a) on the compressor side
) is closed, the relay (PR) is demagnetized by the opening of the break contact (1-1-b) by the excitation of the relay (1-1), and then the break is made by stopping the operation of the first compressor (1). When the contact (1-1-b) returns to closed and the relay (PR) is energized again, the contact (PR-c) is switched to the second relay (4X2) side, and the second compressor side is switched. excitation line (
b) Close the contact (4X2-a) installed in relay (1
-2) break contact (1-2-b) is opened.

With the above configuration, the first compressor (
1) is operating independently, if an individual abnormality occurs in this, the make contact (572
Due to the opening operation of X-al), the excitation line (a) is opened and the compressor (1) is stopped.
The break contact (572X-b) placed in
will be driven. Similarly, if an individual abnormality occurs in the second compressor (2) when it is operating independently, the first compressor (1) will be operated instead. In this way, when one unit is operating at low capacity, if an individual abnormality occurs in the operating compressor, the operation of that compressor is stopped to protect the equipment, and the stopped compressor is operated instead. ,
The cooling action in the evaporator (18) can be continued without interruption, and a situation in which the temperature of the brine etc. increases can be avoided.

Furthermore, in the event of a common abnormality in the system such as a line water outage, the relay (5TIX) is demagnetized to open both excitation lines (a) and (b), and the compressor (1) (2) is
Since the operation of the equipment is stopped, the entire equipment can be protected.

(Effects of the Invention) As described above, according to the present invention, during low capacity operation by controlling the number of units,
If an abnormality occurs in an individual operating compressor, the operating compressor will be stopped, but instead the stopped compressor will be operated as a backup, which protects the equipment while preventing the entire equipment from stopping. This can be avoided and temperature fluctuations caused by the refrigeration load can be reduced.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the operation control of the compressor in the refrigeration v1 unit according to the present invention, Fig. 2 is an electrical circuit diagram of the main parts, and Fig.
The figure is a refrigerant piping system diagram of the entire refrigeration system. (1)...First compressor (2)...Second compressor (100)...Detection means (200)...Detection means (400 )...Capacity control means

Claims (1)

[Claims] 1) Multiple compressors (1) (2) and these compressors (1)
)(2), the refrigeration system is equipped with a capacity control means (400) that adjusts the capacity by controlling the number of units in operation, wherein each compressor (1) (2) has a ) Detection means (100) (2) for detecting abnormal signals occurring individually around the
00), and also includes a low-capacity operation discrimination means (500) for discriminating low-capacity operation when low-capacity operation is performed by controlling the number of units, and when the discrimination means (500) determines low-capacity operation, When an abnormality is detected in the compressor (1 or 2) inside, the compressor (1 or 2) in operation is stopped and the stopped compressor (2 or 1) is operated. Refrigeration equipment characterized by: