JPS61178584A - Operation controller for compressor - Google Patents

Abstract

PURPOSE:To improve the durability of the whole air conditioner apparatus by selecting the compressors so that the operation time becomes uniform, in the control of the compressors, the quantity of which is increased and decreased according to the load. CONSTITUTION:The loads 20-22 of an air conditioner are detected by a load detecting means 1, and the number of compressors in operation at present in detected by an operation detecting means 2. The output of an operation quantity determining means 3 on the basis of the results of the both detection is transmitted to each compressor 10-1-10-n through a control means 5 and a control output circuit 6. In this case, an operation-time detecting means 4 detects the operation time of each compressor from the output of the control output circuit, and input the operation time into the control means 5. Therefore, the control means 5 selects the compressor so that the operation time of each compressor becomes uniform, on the basis of the quantity of operation units instructed by the operation quantity determining means 3, and output is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a compressor operation control device, specifically, an air conditioner using a plurality of compressors in the same refrigerant system.
The present invention relates to an operation control device that controls the operation of the compressor according to the load.

(Prior Art) Conventionally, in an air conditioner using a plurality of compressors in the same refrigerant system, the operation of each compressor is controlled according to load fluctuations, so that air conditioning is performed with a desired number of compressors. ing.

As an example of an operation control device that controls the number of operating machines,
As shown in Japanese Patent No. 8-131385, there are systems in which multiple compressors are started and stopped sequentially in a predetermined order according to load fluctuations, and systems in which multiple blowers, which are not compressors, are installed. There is a known method in which the combinations of blowers to be driven are set in advance, and the combination that provides the optimum operating pattern according to the load is selected from these combinations to start and stop the blowers. ing.

(Problems to be Solved by the Invention) The conventional method for controlling the number of operating units described above involves sequentially starting and stopping a plurality of compressors, or selecting a combination to control the optimal operating pattern. Therefore, the operating time of multiple compressors or blowers varies depending on the changing state of the load, and the operating time of a specific compressor or blower is longer than that of other compressors or blowers, in other words, the operating rate is high. As a result, the life of the compressor with a high operating rate is shorter than that of other compressors, and the life of the air conditioner is determined by the compressor with a short life, and these compressors or blowers are not used as a whole. There was a problem that the durability of the air conditioner deteriorated.

When controlling a plurality of compressors, the present invention considers the operating time of each compressor, and when there is a request to increase the number of operating compressors, selects a compressor with a short operating time and drives it preferentially,
In addition, if there is a request to reduce the number of operating units, compressors with longer operating hours are selected and prioritized to stop, which helps to equalize the operating rate of all compressors and extend the life of the entire air conditioner. This is what I did.

(Means for Solving the Problems) As shown in FIG.
1 to 10-n) according to the load, the operation control device includes a load detection means (1) and each of the compressors (1 to 10-n).
10-1 to 10-n), and the number of operating units is calculated based on the load signal from the load detection means and the operation state signal from the operation detection means. an operation number determining means (3), and each compressor (
10-1 to 10-n), and based on the operation time signal from this operation time detection means and the number of operating units command signal from the number of operating units determining means, the operation is performed. The compressor is characterized by comprising a control means (5) for preferentially driving compressors that have been in operation for a short time when the number of units in operation is increased, and for preferentially stopping compressors that have been in operation for a long time when a command to decrease the number of units in operation is given. be.

(Function) After calculating the required number of operating units based on load fluctuations, the number of operating units is calculated based on the operating time signal from the operating time detection means that detects the operating time of each compressor (10-, ~10-n). If it is necessary to increase it, select the compressor (tO-, ~10-n) that has been operating for a short time up to this point, and start this compressor (10-1 to 10-n) preferentially. At the same time, when reducing the number of operating units, select the compressor (10-1 to 10-n) that has been in operation for a long time up to the present time, and stop this compressor (10+, to 10-n) preferentially. This makes it possible to average the operating times of the compressors (10-1 to 10-n), that is, to average the operating rates, while controlling the number of compressors in operation.

(Example) The one shown in Fig. 3 has multiple compressors (10-1 to 1
(O-n) are connected in parallel, and a four-way switching valve ('
11) is connected to the switching port of this four-way switching valve (11), and a heat source side heat exchanger (12) and a plurality of user side heat exchangers (13-, ~l3-n) are connected to the switching port of the four-way switching valve (11). This is a room-type air conditioning system.

In addition, in FIG. 3, (14) is the receiver, (15-,
~l5-n) and (18-, ~1B-n) are on-off valves, (
17-, ~17-n) is a pressure reducing mechanism, (18) is an accumulator, (19-, ~19-n) is a check valve,
(PS) is a pressure switch provided in the discharge pipe of each of the compressors (10-1 to 10-n).

The present invention controls the number of operating compressors (10-1 to 10-n) and the operating compressors in the air conditioner configured as described above. An example will be explained.

First, the load detection means (1) will be explained.

In the multi-room air conditioning system shown in FIG. 16-, ~1
An on-off valve detection circuit (20
), a temperature detector (21) that detects the room temperature where the user-side heat exchanger is installed, and a room temperature setting device (22), and the room temperature detected by the temperature detector (21) is , the required load is detected by comparing it with the target room temperature set by the room temperature setting device (22).

Further, the operation detection means (2) is configured to detect each compressor (10-1).
- 10-n) is in operation and detects the number of units in operation at the moment. Low pressure pressure detector (22)
Alternatively, the operating state is detected by using a high-pressure pressure detector (23) to detect the pressure of intake gas (LP) during cooling or the pressure (HP) of discharged gas during heating.

The operating number setting means (3) receives the load signal from the load detecting means (1) and the operation detecting means (2).
It calculates the required number of units according to the load based on the operating status signal from the unit, and is equipped with an arithmetic circuit.

Further, the operating time detection means (4) is configured to integrate the operating time of the compressor that has been operating before the point in time when a start or stop command is output from the control means (5), which will be described next. The operating time is detected by still,
In this case, for those that are stopped, the stop time may be subtracted.

Specifically, as shown in Figure 2, an electrolytic capacitor (C,
~Cn), and each of these capacitors (C, ~Cn) is connected to the normally closed contact of the start/stop control relay (52C, ~52Cn) of each of the compressors (10-1 to 10-n), and the first resistance(
R3, ~R8n), and the normally open contacts of the relays (52C1~52Cn) and the second resistors (RR,
〜RRm) is connected to the capacitors (C, 〜C
n) in parallel to form a circuit in which the capacitors (C, ~Cn) are charged while the compressor is stopped and discharged while the compressor is in operation;
~Cn) terminal voltage (V) is output as a signal voltage.

That is, the terminal voltage (V
), the constant changes depending on the operating time of the compressor (10-1 to 10-n), and the time constant of the capacitor (C, -Cn) corresponding to a compressor with a long operating time becomes large. , the terminal voltage (V) can be used as an operating time signal for each compressor.

Incidentally, when all the compressors (10-□ to 1O-n) are stopped, neither charging nor discharging is performed.

Moreover, other time measurement circuits may be used as the operation time detection means (4).

The control means (5) also controls the operation time detection means (4).
) and the number-of-operations command signal from the number-of-operations determining means (3), when commanding an increase in the number of operating units, priority is given to driving the compressor with less operating time, and when issuing a command to decrease the number of operating units. Sometimes the compressor, which has been running for a long time, is prioritized and stopped, and the central processing unit (CP)
The load detection means (1), operation detection means (2) and operation time detection means (4) are connected to the input side of the controller, and the control output circuit (6) is connected to the output side of the controller. ) through each of the compressors (10-1 to 10-n
) are connected to each relay (52C, to 52C,).

The operation time detection means (4) is connected to the output side of the control output circuit (6), and the control output circuit (6)
) The start/stop signals of the respective compressors, which are controlled by the output from the compressors, are fed back and the operating time is integrated.

Further, the central processing unit (CPU) incorporates an operation number calculation circuit constituting the operation number determining means (3), and also incorporates each compression input from the detection circuit constituting the operation time detection means (4). A comparison circuit is built in to compare the operating time of each machine.

Therefore, in the embodiments described above, the number of the user-side heat exchangers (13-, ~13-n) to be used is increased or decreased, and the user-side heat exchangers (13-1 to 13-n) to be used are installed. When the load fluctuates due to changes in indoor temperature, the number of compressors to operate is determined according to this load, and if there is a request to increase the number of compressors that need to be operated, the number of compressors that are not operating will be reduced. The short compressor is selected and driven preferentially.

That is, as shown in Fig. 4, when using three compressors (10-, ~10-.) with the same capacity, these compressors (
10+, ~10-. ) is stopped and a command to operate one compressor is issued, three compressors (10+1 to 10-s
), the compressor (10-, ) with the shortest operating time is
They are driven first, and when a command to operate two more compressors is issued, the two stopped compressors (10+1
') (10-, ), the compressor with short operating time (10
-, ) are then driven. When a command is issued to reduce the number of units by one after a certain period of time, the compressor (10-,) currently in operation is
The operating time of compressor (10-,) is compared and compressor (10-,
If the operating time of the compressor (10-,) is longer than the operating time of the compressor (10-,), the compressor (10-,) is stopped first.

Then, when a command to increase the number of units by one is issued again after a certain period of time, the operating times of the compressors (10-, ) (10-5) that are stopped at that time are compared, and the operating time of the compressor (10-1) is compared. Compressor (
If the operating time of the compressor (10-,) is longer than the operating time of the compressor (10-,), the compressor (10-,) is driven first.

Note that the operating time of the compressor in operation will be longer than the operating time of the stopped compressor, but in this case, it is necessary to stop the operating compressor and start the stopped compressor, which has a shorter operating time. If this happens, the number of times the compressor starts and stops will increase, which may even shorten the life of the compressor.Furthermore, starting and stopping the compressor will cause a loss of capacity in the air conditioner, reducing efficiency. Until a stop command and a start command are issued, a compressor that is in operation continues to operate, and a compressor that is stopped continues to be stopped.

Although the embodiments described above are configured to control the operation of a plurality of compressors used in a multi-room air-conditioning system, the present invention can also be applied to a cooling-only system, even if the system is not a multi-room system.

Further, although the operation control can be simplified if the compressors (10-, to 10-n) have the same capacity, compressors with different capacities may be combined.

Further, each of the compressors (10-1 to 10-n) does not have a capacity control operation structure, but each compressor (10-1 to 10-n) is operated by performing frequency conversion, for example. It may also be configured to perform capacity control operation.

In this case, a frequency setting circuit is provided for each compressor, and the operating time is measured by, for example, calculating a coefficient of the operating frequency in advance and multiplying the operating time by this coefficient.

(Effects of the Invention) As described above, according to the present invention, a plurality of compressors (10-1
~10-n) while controlling the number of units according to the load.
In this control of the number of units, the operating time is taken into consideration, and when an instruction is given to increase the number of operating units, the compressor with the least operating time is driven preferentially.
In addition, when a command is given to reduce the number of operating units, priority is given to stopping the compressors that have been in operation for a long time, so all compressors (10+, ~1
(on) operation time is averaged, and the overall life span can be increased.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is an electric circuit diagram showing an embodiment of the operating time detection means, and FIG. 3 is an example of a multi-room air conditioning system to which the present invention is applied. The refrigerant piping system diagram, FIG. 4 is an explanatory diagram showing an example of operation control of each compressor. (1) Load detection means (2) Operation detection means (3) Operation number determination means (4) Operation time determination means (5)... Control means

Claims (1)

[Claims] (1) Multiple compressors (10-_1 to 10-_n),
An operation control device that controls operation according to load, and includes a load detection means (1) and each of the compressors (10-_1 to 10-
_n); an operation detection means (2) for detecting the operation state of the vehicle; and an operation number determining means (3) for calculating the number of operation vehicles based on the load signal from the load detection means and the operation state signal from the operation detection means; ) and each of the compressors (10-_1 to 1
Operating time detection means (4
), based on the operating time signal from the operating time detection means and the operating number command signal from the operating number determining means, when an instruction is given to increase the number of operating units, the compressor with less operating time is driven preferentially, and the number of operating units is reduced. 1. A compressor operation control device comprising: control means (5) for preferentially stopping a compressor that has been in operation for a long time when a command is issued.