KR100298856B1 - Sequential Circulation Operation Control Method of Parallel Multiple Compressor - Google Patents

Abstract

The present invention relates to a sequential circulation operation control method of a parallel multiple compressor (MULTI COMPRESSOR SYSTEM).

With the economic development, the distribution industry has become larger and more advanced, and the use of low-temperature facilities such as low-temperature warehouses (freezers and refrigerators), freezers, and refrigerated showcases is increasing to preserve products and maintain freshness. Safety management and maintenance are becoming difficult.

As a result, a parallel multi-compressor method is used, which reduces the operating cost and simplifies the refrigeration piping system. In the conventional operation method, a compressor having a low suction pipe pressure setting has a long operation time by setting the suction pipe pressure separately for the compressor in the refrigerator unit. Compressors with long and high suction pipe pressure settings have disadvantages in that the operating time and operating conditions are not uniform for individual compressors due to the short operation time and frequent starting and stopping due to load changes.

The present invention for solving this problem is a sequential circulating operation control method of the parallel multi-compressor to maintain the operation conditions and the operation time evenly by setting the suction pipe pressure range to stop the compressor first started within the set suction pipe pressure range. Would be suggested.

Description

Sequential Circulation Operation Control Method of MULTI COMPRESSOR SYSTEM

The present invention has excellent power saving effect and mechanically stable parallelism when using a large number of low-temperature warehouses (freezers, refrigerators) or showcases for display for the display and storage of refrigerated and refrigerated products that are easily altered in large distribution centers or department stores. The present invention relates to a sequential circulation control method of a parallel compressor (MULTI COMPRESSOR SYSTEM), which is an operation control method of a multiple compressor (multi chiller unit) type.

As is well known, low-temperature warehouses (frozen refrigerators) are used to preserve products and maintain freshness as the retail industry grows and expands along with economic development. In addition, as the use of low-temperature facilities such as low-temperature showcases increases and the facilities become more complicated, safety management and maintenance are difficult with the existing facilities.

Accordingly, a parallel multi-compressor system (MULTI COMPRESSOR SYSTEM) is used, which reduces the operating cost and also simplifies the refrigeration piping facility. As such a conventional operation control method, various types of operation methods are known.

In other words, the compressor with less operating time is checked first by checking the operating time of the compressor individually, and when the compressor is operated under low load when using the operation method in which the compressor with a large operating time stops. In this compressor, the closed end of the short cycle operation is generated by repeating the operation stop. Another control method is to set the pressure in the suction pipe individually and operate in the set area. For example, as shown in FIG. 6, the pressures of the suction pipes are individually set for each compressor, and the first unit operates at a pressure of 1.5 kg / cm 2 or more and stops at a pressure of 0.5 kg / cm 2 or less, and the second unit has a pressure of 2 kg / cm 2 or more. Operating at the pressure of less than 1㎏ / ㎠ and the third unit is operated at the pressure of 2.5㎏ / ㎠ or more and stopped at the pressure of 1.5㎏ / ㎠ or less so that the operation sequence is the 1st, 2nd, 3rd In this order, stop order is 3rd unit, 2nd unit, and 1st unit. Therefore, the operation time of the first unit with low pressure setting is long and the third unit with high pressure setting has a short operation time, so there is a large difference in operating time for each compressor, and the short cycle operation that is restarted immediately when the load of the compressor just stopped increases. The discontinuance is caused.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and an object thereof is to control a compressor in a parallel multiple compressor (multi-refrigerator unit) by a sequential circulation control method.

That is, the sequential circulation control method of the parallel multiple compressor is constructed by measuring the suction pipe pressure with the pressure sensor and receiving the operation / stop signal from the pressure sensor and operating the compressor one by one when the operation signal is stopped, and by stopping the compressor which is operated first when the stop signal is received. It is to improve the problem.

1a, b is a block diagram of the present invention.

2 is an explanatory view of the pressure range setting in the present invention.

3 is an operation explanatory diagram of the operation and stop state by the pressure setting of the present invention.

4 is an explanatory diagram of the operation and stop sequence of the present invention.

Figure 5a is a flowchart of the operational description of the present invention.

5b is a circuit diagram of the present invention.

6 is a conventional explanatory diagram in which the suction pipe pressures are individually set by the compressors individually.

<Description of the symbols for the main parts of the drawings>

10: low temperature warehouse TC: temperature controller

SV: Electron valve

In order to achieve the above object, the present invention sets a proper suction pipe pressure in advance, receives a run / stop signal from a suction pipe pressure sensor, and sequentially operates the compressors one by one if it is an operation signal. By configuring the sequential circulation control method, the compressor just stopped can be prevented from restarting immediately and the operating conditions can be maintained evenly.

Detailed embodiments will be described below with reference to the accompanying drawings.

1 is a configuration diagram of the present invention, Figure 2 is a pressure range setting explanatory diagram in the present invention, Figure 3 is an operation explanatory diagram of the operation and stop state by the pressure setting and Figure 4 is an explanatory view of the operation and stop sequence.

As shown in FIG. 1, the low temperature warehouse, the freezer, the freezer and the showcase (hereinafter referred to as the low temperature warehouse) 10 are connected in parallel, respectively, and the refrigerator unit is also configured in a parallel multiple compressor method and the temperature in the low temperature warehouse 10. If the temperature is higher than the proper temperature, the electronic valve SV is opened by the temperature controller TC, and the refrigerant gas flows through the evaporator and enters the suction pipe. When the suction pipe pressure increases and reaches the set pressure LOAD, the operating signal is sent from the suction pipe pressure sensor. The compressor of the first unit is operated and the compressor is operated in the order of the second, third, ... order according to the continued operation signal, and when the low temperature warehouse 10 reaches an appropriate temperature, the temperature controller TC When closing the solenoid valve (SV), the flow of refrigerant is blocked and the suction pipe pressure decreases to reach the set pressure (UNLOAD). It will achieve the one group, the third exhalation, ... parallel multi-compressor in order to stop the sequential rotation control method.

EXAMPLE

As shown in FIG. 1, when two or more low temperature warehouses 10 and a compressor are connected in parallel, and the suction pipe pressure is set as shown in FIG. 2, thereby operating in the order shown in the flowchart of FIG. It operates according to the circuit structure of FIG.

That is, when the temperature is higher than the proper temperature in the low temperature warehouse 10, the electronic valve SV is opened by the temperature controller TC, the refrigerant is introduced, the suction pipe pressure increases, and the pressure sensor reaches the set pressure LOAD point. When the first compressor is operated by receiving the operation signal from the suction tube and the suction pipe pressure does not decrease within the set time, the second compressor is operated by receiving the operation signal from the suction tube pressure sensor, and then the third compressor is operated in the order of the third compressor.

It maintains its current state in the pressure state between LOAD point and UNLOAD point, which is the setting range. When temperature of low-temperature warehouse 10 reaches the proper temperature, the electronic valve (SV) is closed by the temperature controller (TC) and the inflow of refrigerant is stopped and the suction pipe When the pressure is lowered and the suction line pressure reaches the UNLOAD point, it receives the stop signal from the suction pipe pressure sensor and stops from the first unit operated first, and stops the second unit with the continuous stop signal. The fourth unit is operated and the first unit is operated by the continuous signal. When the load decreases and the suction tube pressure reaches the UNLOAD point, the third unit is stopped, and the stop signal of the suction tube pressure sensor is continued. Is stopped.

Therefore, each of the refrigerators in the refrigerator unit of the parallel multiple compressor method is to be cyclically operated, and the circuit configuration of this embodiment is shown in Figure 5 (b).

When the power is turned on according to this circuit configuration, the contact 10 turns off after 1 second from the ON by the TOFF timer (TM), the relay (AX11) enters the self-maintaining state, the contact 11 turns on and becomes ready for operation of the first unit. When the pressure increases and the suction pipe pressure reaches the LOAD point, the operation signal is received from the suction pipe pressure sensor and the relay (AX1) is excited and the contact 12 is turned on.The relay (AX12) is self-holding and the contact 13 is turned on to operate the first unit Contact 15 turns OFF and the self-holding of the relay (AX11) is released to release the ready operation of the first unit, and the contact point 14 is turned ON, the relay (AX21) is excited to enter the self-holding state and the second unit is ready for operation. If the pressure does not decrease even after the set time, and if it is more than LOAD, when the contact 17 is turned on by receiving the operation signal from the pressure sensor, the relay (AX22) is self-maintained and the second unit is operated by the contact 18 and the relay (AX 31) is self-sustained and enters the ready state for operation of Unit 3.

When the suction line pressure is within the pressure setting range (between LOAD and UNLOAD points), the current compressor operation status is maintained and the load decreases, the suction pipe pressure decreases, and when the suction pipe pressure reaches the UNLOAD point, a stop signal comes from the suction pipe pressure sensor and contact point 18 Is turned off, the relay AX12 is deactivated, the contact 13 is turned off to stop the first unit, and the contact 14 is turned off to release the preparation state of the second unit.

When the operation signal is received by the operation as described above, the third unit is operated and the continued operation signal is operated in the order of the fourth unit and the first unit, and when the stop signal is received, the second unit is stopped and the third is continued. The unit will stop in the order of Units No. 4 and No. 1.

Depending on the pressure of the suction pipe, the compressor operation amount is changed from 0% to 100% (0%, 25%, 50%, 75%, 100% in the case of 4 stage parallel connection). The invention has the advantage of being able to operate with the proper operation amount according to the load at the time point and to prevent excessive operation of the compressors individually in the parallel multiple compressor (multi-cooler unit) and to maintain the operation conditions evenly.

Since the present invention controls the sequential circulation operation of the MULTI COMPRESSOR SYSTEM as well known, the compressor is first stopped to prevent the burden on a particular compressor in the unit and to maintain the operation conditions evenly. It is a useful invention that can be balanced and stable operation by maintaining the operation condition evenly because it reduces the failure factor and operates a large amount of operation required at the time of operation.

Claims (1)

Two or more compressors are connected in parallel in the refrigerator unit to form a parallel compressor system, and if the temperature is higher than the proper temperature in the low temperature warehouse 10, the temperature controller (SV) is used. When the refrigerant gas flows into the suction pipe through the evaporator and the pressure increases and reaches the set pressure, it receives the operation signal from the suction pipe pressure sensor and operates the compressor of the first unit. When the compressor is operated in the order of the exhalation ..... and the temperature of the low temperature warehouse 10 reaches a proper temperature, the temperature of the refrigerant is blocked by closing the electronic valve SV by the temperature controller TC so that the pressure of the suction pipe is reduced. When the pressure decreases and reaches the set pressure, the stop signal is received from the suction pipe pressure sensor, and the first and second units are stopped in order from the first unit to the second unit and the third unit. When the temperature rises in the low temperature warehouse 10, the electronic valve SV is opened by the temperature controller TC, and the refrigerant gas flows into the suction pipe through the evaporator, and the pressure increases. When the pressure reaches the set pressure, the operating signal is received from the suction pipe pressure sensor. Step 4, 3, 2, 1 in the order of operation, and when the temperature of the low-temperature warehouse 10 is in an appropriate state, the electronic valve (SV) is closed by the temperature controller TC to cool the refrigerant. When the flow is blocked and the suction pipe pressure decreases to reach the set pressure, the controller receives the stop signal from the suction pipe pressure sensor and stops in the order of No. 4, No. 3, No. 2 and No. 1, and operates under low load. Even when the second unit is stopped after the operation of the second operation is a sequential circulation operation control method of a parallel compressor (MULTI COMPRESSOR SYSTEM) characterized in that it comprises a step to be operated starting from the third unit.