JPH02267469A - Air conditioner capacity control operation method - Google Patents

Abstract

PURPOSE:To improve a follow-up characteristic of variation in load, improve an economical characteristic in operation and realize a uniform utilization of a compressor mechanism by a method wherein a capacity of an electric motor for one compressor mechanism is controlled in response to a requested load and capacities of a plurality of electric motors for compressors can be continuously and simultaneously controlled for a load larger than the requested load. CONSTITUTION:Several rotary compressor mechanisms such as scrolls arranged in an air conditioner and an electric motor are operated through an inverter. Any one of the compressors is started from a minimum frequency after starting of the air conditioner and the frequency is gradually increased toward the requested output. If the load is satisfactory under operation of one compressor, its operating frequency is stabilized between its minimum value and an intermediate value 2. In case that the load is large in value and output is insufficient, an operating frequency of the electric motor for the compressor is immediately increased up to the intermediate value 2 and further even in case of this increased state, the output is further short in value, the frequency is decreased once to the minimum frequency value and then the second compressor mechanism is started to operate. After the second compressor mechanism shows a coincidence with the same minimum frequency, the frequencies of the two compressors are simultaneously and gradually increased to make a coincidence with the required output and then a stable operation of them is carried out.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to relatively large capacity air conditioners that perform capacity control;
The present invention relates to a method for controlling the optimum capacity when 1 tlJ.

[Conventional technology]

Conventional multiple pressure a! ! Alternatively, the capacity control operation method for a relatively large capacity air conditioner with a compression mechanism involves operating multiple compressors or stopping one of them to perform discontinuous capacity control operation depending on the required load. By using an inverter to continuously control each compressor, we have been able to control the overall capacity of the G4 air compressor. Related to these devices, for example, Utility Model Application No. 58-85
There is issue 159.

[Problem to be solved by the invention]

The above-mentioned conventional technology can deal with rough changes in the load of the empty VIL machine, but it can handle small loads caused by changes in the temperature inside the cage, changes in the coming and going of people, and changes in solar radiation using normal pressure machine start/stop methods. This is equivalent to control, and the poor follow-up performance results in excessive cooling and overheating, which is uneconomical.Also, even when an inverter is used, each part starts and stops independently, so the multiple compressor parts of the air conditioner as a whole are In terms of mechanical life, no points were given for averaging. Furthermore, in order to increase the output as necessary to cope with low to high loads, the compressor itself is operated at an unnecessarily high frequency without considering its high efficiency, or multiple compression mechanisms are operated at different frequencies. There is also the problem that the compression mechanism section, which is operated at a high frequency, is subject to a heavy mechanical load. In addition, simultaneous starting times may occur, resulting in an increase in the peak starting current.

Taking these circumstances into consideration, the present invention aims to follow load changes, improve economic efficiency, equalize the use of compression mechanisms, and suppress the starting current of multiple compressors.

Means for solving csg J In order to achieve the above purpose, the rotary compression mechanisms such as nine or more scrolls and electric motors installed in the air v4 phase machine are operated by inverters, and the electric motors are connected to each other. After starting one inverter, the frequency of the inverter is gradually increased, and then the other inverter is started depending on the load.
Take measures such as operating the machine. In addition, when operating one electric motor for a compression mechanism, it should be set to an intermediate frequency from the inverter's lowest drive frequency to the highest m dynamic frequency, so that it is used in the high efficiency range of the compressor, and when using multiple units. There are 9 types that allow multiple units to operate at the same frequency starting from the lowest frequency.

[Effect]

Since the compressor is driven using an inverter, it maintains good load following characteristics, but due to its relatively large capacity, multiple electric motors and compression mechanisms are controlled so that they work closely with each other. At the time of starting, in order to suppress the beep current, the first compression mechanism and the electric motor are operated to gradually increase the frequency, and depending on the load condition, other electric motors are also driven to adjust the empty fJ4flJl capacity. Operation stop fl
k The pressure #I mechanism side which is stopped first is started preferentially at the next start-up to average out the operating time. In addition, while one compressor is in operation, the inverter drive frequency is limited in consideration of the high-efficiency operating range of the compressor, and multiple compressor motors are driven at a high frequency only when the air conditioner requires maximum output. and ensure the necessary output.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 2 and 8.

The present invention relates to a pressure mechanism built into an air conditioner and its driving type l.
The case where there are two pairs of Ih machines is shown. In Figure 2, the horizontal axis shows the output of the pressure ia machine motor operation, the inverter frequency, and the vertical axis shows the output. 01 shows the air conditioner output diagram when one compression mechanism drive motor is controlled and operated, and 2 shows the air conditioner output diagram when two motors are controlled in the same way. The air conditioner output diagram when it is operated is shown. In addition, in Fig. 8, the horizontal axis shows the pressure m @ motor operating inverter frequency, and the vertical axis shows the compressor efficiency, and 3 shows the compressor efficiency characteristics when the pressure ita machine is operated from low frequency to high frequency. It is something that In addition, Figure 2,
The minimum and maximum on the horizontal axis of FIG. 8 indicate the minimum and maximum of the motor drive frequency of the inverter, and the middle, middle 1, middle 2, etc. indicate any frequency between them. Also,
FIG. 1 shows an example of the control flow of the present invention. According to the present invention, when the empty G4 machine starts operating, one arbitrary compression mechanism is started from the minimum frequency and the frequency is gradually increased toward the required output. In this state, the compressor motor 1 in Fig.
It is shown on the line of output l during platform operation.

If the load is satisfied by operating one compressor a, its operating frequency will be stable between the minimum and intermediate 20 degrees.

Further, if the load is large and the output is unyielding, the compressor motor operating frequency is immediately increased to intermediate 2, and if it is still insufficient, it is once lowered to the minimum frequency and the second white compression mechanism is started. After the second compression mechanism reaches the same minimum frequency, the frequency of the two compression mechanisms is gradually increased to match the required output and stable operation is achieved. In this case, the output at the intermediate frequency when one compressor is operated and the output at the minimum frequency when two compressors are operated are the same or around it, and the output is discontinuous due to switching between one and two compressors. Preventing sex. If more output is required, increase the output to the maximum frequency for 2 melee. On the other hand, if a reduction in output is requested, it will operate in the opposite direction to continuously comply with the request. An example of a 7a-chart relating to this control method is shown in FIG.

Further, FIG. 8 shows the efficiency with respect to frequency when a rotary pressure m@ structure such as Meklor is operated, and the relationship with FIG. 2 will be explained. When operating one compression mechanism, from minimum to middle 2
We are conscious of the relatively efficient human area shown in Figure 8, which uses frequencies up to . In addition, the region B has a relatively high frequency and low efficiency, so when output is required, @
By using more energy, energy saving will be improved. As shown in FIG. 1, by starting the compressor one after another, it is possible to equalize the operating time and maintain continuity and good load followability.

〔Effect of the invention〕

According to the present invention, multiple compressors can be operated continuously and efficiently. , the overall efficiency of the v4 machine is high. For example, in Fig. 8, there is usually a difference of about 1011 between the highest efficiency region A and the maximum frequency efficiency, and considering that the average load factor of oqv4 iso is 40 to 60 g! This means that the horizontal adjustment machine can always be operated with high efficiency. In addition, by controlling the operation of the present invention, it is possible to achieve pressure averaging (operation time) of 18 machines by rotary operation and one-stroke operation, and there are effects such as highly efficient continuous control.

[Brief explanation of drawings]

FIG. 1 shows a flowchart of the ittIjgl operation showing one embodiment of the present invention. FIG. 2 is a relationship diagram between compressor operating frequency and output, and FIG. 8 is a characteristic diagram of the compressor. l...Output when operating one pressure Ia unit 2...
Pressure i#A mechanical electricity! Output when two JB machines are operated 8...Compressor efficiency characteristic line. Condolence 1 Figure 1 r1 thing [hlH4,. 51 hours of luck at first glance! Force 2 Pressure m O ship t cutting 5 2 cells soft time n output pressure - 1

Claims (1)

[Scope of Claims] 1. A compressor, a heat exchanger, a pressure reduction mechanism, a blower device, and an air conditioner housing these, which includes a plurality of electric motors and compression mechanisms for driving the compressor, and the electric motors are connected to an inverter, etc. The capacity of one compressor motor is controlled individually from the minimum frequency that can be driven by the inverter to an intermediate frequency before the maximum frequency according to the required load, and multiple motors are operated for larger loads. A capacity control operation method for an air conditioner, characterized in that the electric motor for the compression mechanism of is simultaneously operated under capacity control between the minimum frequency and the maximum frequency that can be driven by an inverter, thereby making it possible to continuously control the capacity from a minute load to a large load. 2. In the apparatus according to claim 1, when starting operation, one of the compressor mechanism electric motors is started, and the operating frequency is gradually increased to match the load, and when the capacity is too large for the load, An air conditioner characterized in that when a plurality of compressor mechanisms are in operation, the electric motor that started first is stopped first, and after all the compressors are stopped, when starting the next time, the electric motor that has stopped first is started. Capacity control operation method.