KR20040050474A - Compressor control method for heat pump system using multi compressors - Google Patents

Abstract

The present invention relates to a compressor control method of a heat pump system using a plurality of compressors. When a plurality of compressors are simultaneously operated, a heating load is reduced during a heating operation, and some compressors are stopped and some compressors are selectively operated. If the room temperature suddenly decreased due to the stop of the part of the compressor enters the desired temperature range according to the capacity of the part of the compressor running within the set time, the stopped compressor is not restarted and consumed to restart the compressor. Since the power can be reduced, the efficiency of the heat pump system can be improved.

Description

Compressor control method for heat pump system using multi compressors}

The present invention relates to a compressor control method of a heat pump system employing a plurality of compressors, and in particular, when some compressors are stopped due to a decrease in the heating load during the heating operation of the heat pump system. A compressor control method for a heat pump system employing a plurality of compressors to prevent a compressor from being restarted.

In general, a heat pump system includes a compressor for converting a gaseous refrigerant at low temperature and low pressure into a gaseous state refrigerant at high temperature and high pressure, and a condenser for converting a gaseous state refrigerant at high temperature and high pressure changed into a liquid refrigerant at medium temperature and high pressure. And an expansion device for changing the medium-temperature high-pressure liquid state refrigerant in the condenser into a low-temperature low-pressure liquid state refrigerant, and a four-way valve for changing the flow path of the refrigerant according to a cooling and heating mode.

In the heat pump system, the indoor heat exchanger and the outdoor heat exchanger have different roles depending on the cooling and heating mode.In the heating mode, the indoor heat exchanger plays the role of a condenser and the outdoor heat exchanger plays the role of an evaporator. And the outdoor heat exchanger acts as a condenser.

In addition, recently, by applying a plurality of compressors having different capacities, the capacities can be varied according to cooling loads or heating loads, thereby optimizing cooling and heating efficiency.

As shown in FIG. 1, a compressor control method according to a heating load in a heating operation of a heat pump system to which the plurality of compressors is applied includes a heating load when the plurality of compressors are simultaneously operated in a first section at an initial stage. When a part of the compressor is stopped in the second section, the room temperature 2 decreases rapidly due to the stop of the compressor.

Therefore, in the second section, the room temperature 2 is not maintained within a range of a predetermined set value from the desired temperature and the desired temperature according to the capacity of the compressor operated among the plurality of compressors, and the temperature at which the set value falls from the desired temperature. The room temperature 2 falls below.

As described above, when the room temperature 2 falls, it is determined that the heating load is increased, and the plurality of compressors are simultaneously operated again in the third section.

However, the compressor control method of the heat pump system according to the related art as described above has a heating load that is reduced, so that some of the plurality of compressors are stopped, so that the rapidly decreasing room temperature is dependent on the capacity of the compressor operating according to the heating load. Since the plurality of compressors simultaneously operate within the time required to stabilize within the desired temperature range, power consumption is increased, thereby degrading the efficiency of the heat pump system.

The present invention has been made to solve the above-mentioned problems of the prior art, the object of which is to stop a portion of the plurality of compressors are simultaneously operated during the heating operation of the heat pump system to which a plurality of compressors are applied at the same time the reduction of the heating load In this case, the present invention provides a compressor control method of a heat pump system using a plurality of compressors that can reduce power consumption by determining whether a stopped compressor is restarted according to an indoor temperature after a lapse of a stabilizing indoor temperature.

1 is a state diagram showing the operating state of the compressor according to the room temperature in the heat pump system applying a plurality of compressors according to the prior art,

2 is a flowchart illustrating a compressor control method of a heat pump system to which a plurality of compressors according to the present invention is applied;

3 is a state diagram showing the operating state of the compressor according to the room temperature in the heat pump system to which a plurality of compressors according to the present invention are applied.

According to a feature of a compressor control method of a heat pump system employing a plurality of compressors according to the present invention for solving the above problems, a first step of simultaneously operating a plurality of compressors during the heating operation of the heat pump system, and the The second stage in which some of the compressors are stopped in accordance with the decrease in the heating load of the plurality of compressors in the first stage, and whether or not the compressor stopped in the second stage in accordance with the room temperature falling in accordance with the compressor stop of the second stage The third step is determined to include.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram illustrating a heating cycle of a heat pump system to which a plurality of compressors are applied, and includes first and second compressors 11 and 12 having different capacities for compressing a refrigerant into a gas refrigerant having a high temperature and high pressure. An indoor heat exchanger 14 for condensing the refrigerant compressed by the first and second compressors 11 and 12 with indoor air to condense it into a liquid refrigerant of medium temperature and high pressure, and the refrigerant passing through the indoor heat exchanger 14 at low temperature and low pressure. Expansion valve 15 for reducing the pressure with liquid refrigerant, an outdoor heat exchanger 16 for exchanging the refrigerant passing through the expansion valve 15 with outdoor air, and a refrigerant having passed through the outdoor heat exchanger 16. And an accumulator 17 which separates the liquid refrigerant from the phase and supplies only the gas refrigerant to the first and second compressors 11 and 12.

In addition, the heat pump system using the two compressors includes check valves 11a and 12a for preventing backflow of the compressed refrigerant of the first and second compressors 11 and 12, and the first and second compressors 11. And a four-way valve 13 for changing the role of the heat exchanger by switching the flow path of the refrigerant having passed through 12).

As shown in FIG. 3, in the heat pump system to which the plurality of compressors configured as described above are applied, the compressor control method according to the heating load is first operated in the first stage and the heating operation is performed. )

Here, when the plurality of compressors are composed of first and second compressors 11 and 12, and the refrigerant compression capacity of the first and second compressors 11 and 12 is 40% and 60%, respectively, The first and second compressors 11 and 12 are operated simultaneously to achieve 100% refrigerant compression.

At this time, the refrigerant compression capacity and number of the two compressors (11, 12) can be changed according to the use and need.

In the second stage, when the heating load of the plurality of compressors is reduced in the first stage, some of the compressors are stopped and some of the compressors are selectively operated (see S2 and S3).

That is, when the heating load decreases while the first and second compressors 11 and 12 are simultaneously operated to achieve 100% refrigerant compression, only the second compressor 12 is selectively operated.

The third step detects the room temperature when some of the compressors are selectively operated in the second step (see S4).

In the fourth step, when the one of the plurality of compressors is stopped, the indoor temperature decreases rapidly. The desired temperature range according to the capacity of the compressor selectively operated in the second step within the set time, that is, the desired temperature. It is determined whether to enter the temperature range having a predetermined set value based on the temperature (see S5).

In the fifth step, when the room temperature enters the desired temperature range within the set time in the fourth step, the compressors other than the compressor selectively operated in the second step maintain the stopped state. (See S6.)

If the room temperature does not enter the desired temperature range during the set time in the fourth step, the plurality of compressors are simultaneously operated to solve the heating load. (See S7.)

The compressor control method of the heat pump system to which the plurality of compressors according to the present invention is applied will be described in more detail with reference to FIG. 4. First, when the plurality of compressors are simultaneously operated in the first section and the heating operation is performed. When the heating load is reduced, some of the plurality of compressors are stopped and some of the compressors are selectively operated as in the second section.

At this time, when some of the compressors are stopped, the room temperature 20 decreases momentarily. In the second section, whether the room temperature enters the desired temperature range according to the capacity of the compressor that operates the room temperature for a set time T. Will be judged.

Therefore, when the room temperature enters the desired temperature range within the set time T, restart of the compressor stopped in the second section is not required.

That is, when 100% refrigerant compression is performed by the first and second compressors 11 and 12, the heating load is reduced, and when the second compressors 11 and 12 are selectively operated, the first stopped by the heating load. The compressor 11 causes the room temperature to drop rapidly. At this time, if the room temperature 20 enters the set time T within the desired temperature range according to the refrigerant compression capacity of the second compressor 12, the room temperature 20 ) Is determined to be stabilized, and the first compressor 11 maintains a stopped state.

As a result, the compressor control method of the heat pump system to which the plurality of compressors according to the present invention is applied has a rapid decrease in room temperature when some compressors are stopped due to a decrease in the heating load while the plurality of compressors are simultaneously operated and the heating operation is performed. When it enters the desired temperature range according to the capacity of the compressor that is selectively operated according to the heating load within the set time, it is determined that the heating load is not increased or decreased and will not restart the stopped compressor according to the decrease in the heating load. .

Compressor control method of a heat pump system using a plurality of compressors according to the present invention configured as described above, if a plurality of compressors are operated at the same time, the heating load is reduced during the heating operation is performed, some compressors are stopped and some compressors In the case of the selective operation, if the room temperature suddenly decreased due to the stop of the part of the compressor enters the desired temperature range according to the capacity of the part of the operated part of the compressor within the set time, the stopped compressor is not restarted. In order to reduce the power consumed to achieve the effect of improving the efficiency of the heat pump system.

Claims (2)

A first step of simultaneously operating a plurality of compressors when performing a heating operation of the heat pump system; A second step in which some of the compressors are stopped according to a decrease in the heating load of the plurality of compressors of the first step; And a third step of determining whether to restart the compressor stopped in the second step according to the room temperature lowered according to the stop of the second step of the compressor. The method of claim 1, The third step may include a first step of decreasing a room temperature according to the stop of the compressor of the second step; And a second step of restarting the compressor stopped in the second step if the room temperature lowered in the first step does not enter the desired temperature range according to the capacity of the compressor operated in the second step within a set time. Compressor control method of a heat pump system characterized in that.