JPS6325446A - Control of air-conditioning machine - Google Patents

Abstract

PURPOSE:To permit electric power necessary for the operation of an airconditioning machine to be minimized while exhibiting a proper cooling capacity, by a method wherein a control circuit for operating the air-conditioning machine so that the sum of an electric power consumption for a compressor and the electric power consumption for an indoor side fan is minimized upon operating the air-conditioning machine, is provided in the title machine. CONSTITUTION:An electric power consumption upon the stationary operation of an air- conditioning machine is measured, and the rotating number of an indoor side fan is increased by DELTAF. Next, a room temperature and an overheating degree after increasing the rotating number of the indoor fan by DELTAF are measured, and the measured values are compared with set values respectively to confirm a stationary operating condition while meeting with respective set values and measure the electric power consumption at that time. When the electric power consumption compared with the initially measured electric power consumption is reduced, the rotating number of the indoor fan is increased by DELTAF further. The electric power consumption is measured after the room temperature and the overheated degree have arrived at stationary conditions while meeting with respective set values, then, the measured values are compared with the electric power consumption measured at previous time. When it is decreased, the same operation is repeated further. When it is increased, the rotating number of the indoor side fan is reduced into a reverse direction to the increasing direction of a previous time, and the operation of the air-conditioning machine is controlled so that the electric power consumption is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is an air conditioner (hereinafter sometimes simply referred to as an air conditioner) applied to communication equipment rooms, computer rooms, etc. The present invention relates to a method of controlling an air conditioner in which an indoor blower consumes a large proportion of power.

(Prior art and problems to be solved by the invention) In the conventional air conditioner control method, the power consumption of the blower is ignored,
Control was focused only on the power consumption of the compressor. However, in air-powered IS machines for communication equipment rooms or computer rooms, the power consumption of the blower is a large proportion of the annual power consumption, and even if only the power consumption of the compressor is minimized, there will be no energy saving effect. The problem was that it was small.

(Object of the Invention) An object of the present invention is to solve the problems of conventional air conditioner control methods by controlling the indoor blower by controlling the rotation speed of the indoor blower in addition to operating the compressor and expansion valve. An object of the present invention is to provide a control method for an air conditioner that can control the rotation speed of the air conditioner and minimize the power required for operating the air conditioner while exhibiting an appropriate cooling capacity.

(Means for Solving the Problems) The present invention was proposed to solve the above problems, and when operating an air conditioner, the sum of the compressor power consumption and the indoor blower power consumption is the minimum. It is characterized by having a control circuit for operating the air conditioner to minimize the power required to operate the air conditioner, including not only the power consumption of the compressor but also the power consumption of the indoor blower. It is something.

Embodiments of the present invention will be described below with reference to the drawings. In addition,
The embodiments are merely illustrative, and it goes without saying that various changes and improvements may be made without departing from the spirit of the invention.

FIG. 1 shows a system schematic diagram of the control method of the present invention. In the figure, 1 is a compressor whose capacity is variable by controlling the rotation speed;
2 is a condenser, 3 is an expansion valve whose opening can be controlled, 4 is an evaporator,
5 is an outdoor blower that together with condenser 2 constitutes an off-campus heat exchanger.
6 is an indoor blower that together with the evaporator 4 constitutes an indoor heat exchanger.
7 is superheat degree detection means, 8 is room temperature detection means, 9 is blower current value detection means, 10 is compressor current value detection means, 1 is blower rotation speed control means, 12 is compressor rotation speed control means, 1
3 is an expansion valve opening control means, and 14 is a calculation device. In an air conditioner with such a configuration, the measured values of the current value, degree of superheating, and room temperature of the indoor blower 6 and compressor 1 are calculated by a calculation device so that the cooling capacity, degree of superheating, and temperature of the evaporator refrigerant all satisfy the permissible values. The calculation is performed and signals are sent to the compressor rotation speed control means 12, the indoor blower rotation speed control means 11, and the expansion valve opening degree control means 13 to manipulate the compressor rotation speed, the indoor blower rotation speed, and the expansion valve opening degree. . Before describing these operations in detail, the relationship between the power consumption of the air conditioner and the indoor blower will be described.

FIG. 2 is a diagram showing the relationship between the power consumption of the air conditioner and the rotational speed of the indoor fan. This figure shows the relationship between the compressor l and the indoor blower 6 relative to the rotation speed of the indoor blower 6 when the rotation speed of the compressor 1 and the rotation speed of the indoor blower 6 are controlled so that the cooling capacity is constant. Indicates the power consumption value. As shown in the figure, as the rotation speed of the indoor blower 6 increases, the power consumption (Pf) of the indoor blower 6 increases, but the compressor 1
The power consumption (Po) tends to decrease. Therefore, the sum of the power consumption of the compressor 1 and the indoor blower 6 (P
The curve t) has a minimum power consumption value Pm1n at a certain rotational speed Nf of the indoor fan 6. Therefore, this minimum value Pml. It can be seen that if the air conditioner is operated at the indoor blower 60 rotation speed Nf and the compressor 1 rotation speed Nc (not shown) at that time, highly efficient operation can be expected.

Note that in air conditioners applied to communication equipment rooms, computer rooms, etc., the indoor blower is designed to be large in order to sufficiently air the inside of the cabinet or housing in which electronic equipment is mounted. Therefore, when minimizing power consumption, it is possible to ignore the power consumption of other devices such as outdoor fans.

Next, with reference to FIG. 1, the control method of the present invention will be explained along with the block diagram of power consumption minimization control shown in FIG. 3 and the control algorithm shown in FIG. 4. As shown in FIG. 3, the power consumption 15 (which can be substituted for the current value of power consumption Vi referred to here; the same applies hereinafter) is input to the arithmetic unit 16 for control, and the power consumption is calculated to minimize the power consumption. The arithmetic processing is performed, an indoor blower rotation speed control signal 17 is output, and the rotation speed of the indoor blower 6 is controlled by the indoor blower rotation speed control means.

When the rotation speed of the indoor fan 6 is controlled, the cooling capacity (room temperature) or degree of superheating of the air conditioner changes, so the room temperature 18 and the degree of superheating 19 are compared with the room temperature setting value 20 and the degree of superheating setting value 21, respectively. The results are input to the arithmetic unit 16, which performs arithmetic processing to control the rotation speed of the compressor 1 and the opening degree of the expansion valve 3, so that the compressor rotation speed control signal 2'l and the expansion valve opening degree control signal 23 are The rotation speed of the compressor 10 and the opening degree of the expansion valve 3 are controlled by the compressor rotation speed control means 12 and the expansion valve opening degree control means 13, respectively. In this way, the minimum power consumption operation of the air conditioner is performed. FIG. 4 is a control algorithm showing the above control method. In the figure, phase (1) is the phase from startup to steady operation of the air conditioner, in which the indoor blower rotation speed is set to the rated value, and the compressor rotation speed and expansion valve opening are operated to their respective set values. It becomes a steady operating state. In phase (U), power consumption during steady state operation is measured, and the indoor fan rotation speed is increased by ΔF.

Next, in the phase (Cao), the indoor fan rotation speed is set to ΔF.
Measure the compressor rotation speed and expansion valve opening after increasing,
Compare it with each set value, check the steady operation state, measure the power consumption at that time, compare it with the power consumption measured in phase (II), and check whether the power consumption of phase (1) is the same as that of phase (II). If it is lower than the power consumption, the rotation speed of the indoor fan is further increased by ΔF in the same direction as the direction in which the rotation speed of the indoor fan was increased in phase (II). As a result, the compressor rotation speed and expansion valve opening are manipulated,
After the room temperature and degree of superheating reach a steady state, measure the power consumption, compare it with the power consumption suppressed in the previous phase (II), and if it has decreased, repeat the operation in phase (jl) to reduce the consumption. Control the power so that it is at its lowest value.

However, if the comparison result with the previous power consumption has increased, the indoor fan rotation speed is decreased in the opposite direction to the previous increase/decrease direction of the indoor fan rotation speed. In addition, what was explained as the measurement of power consumption in the above explanation is the total power consumption of the compressor 1 and the indoor fan 6, and in FIG. 1, the current value detection means of each of the compressor 1 and the indoor fan 6 is These values correspond to 10 and 9.

Furthermore, the rotation speed control of the indoor blower 1 will be explained using FIG. 5. FIG. 5 shows an example of how the sum of compressor power consumption and indoor blower power consumption changes when controlled according to the control algorithm of the present invention. When the indoor fan rotation speed Nfo is changed from state S by a small amount ΔF, state S is reached.
Becomes 1. The power consumption P1 at this time is measured, and if it has increased more than the power consumption PO in the state S6, move from the state S by a minute amount ΔF in the opposite direction to the state S! shall be. This state S
If the power consumption P in state 1 is reduced compared to the power consumption in state SO, the indoor fan rotation speed Nf2 is further moved by ΔF in the same direction as when it was moved from state S0 to state S3. Make it. Repeat the same operation below. In this way, the room temperature and the degree of superheat are maintained and controlled at set values so that power consumption is always minimized.

(Effects of the Invention) As explained above, if the present method is used for control, the following effects can be obtained.

(b) Power consumption of the compressor and blower can be reduced.

(b) In cases where the indoor blower consumes a large amount of power, such as an air conditioner for a computer room, bamboo can effectively save energy.

(c) By applying it to a refrigerator for supplying cold water, the power of the cold water pump can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of the control method of the present invention, and Fig. 2 is a system diagram of the control method of the present invention.
Figures 1 and 3 are block diagrams of the power consumption minimization control, and Figure 4 shows the relationship between the sum of the compressor power consumption and the fan power consumption with respect to the fan rotation speed when the cooling capacity is constant. FIG. 5, which is a diagram showing the control 1 algorithm, is a diagram showing an example of the control progress when control is performed according to the control algorithm of the present invention. 1... Compressor, 2... Condenser, 3... Expansion valve, 4
...Evaporator, 5.Outdoor blower, 6.Indoor blower, 7.Superheat degree detection means, 8.Room temperature detection means, 9.Blower current value detection means. , IO... Compressor current value detection means, ll... Blower rotation speed control means, 1
2... Compressor rotation speed control means, 13... Expansion valve opening degree control means, l4... Arithmetic device. Figure 1/'-fi-Atsuberosu 14-Ensemble U MNa Book 4 Ken M Column 1i Condylar Procedure Neichi Seishicho (Voluntary) November 4, 1985 Commissioner of the Patent Office Black 1) Mr. Ming ill 1. Indication of the case 1985 Vi Revision Request No. 168139 2. Name of the invention Control method for 10 air conditioners 3. Relationship to the case to be amended Name of patent applicant (422) Nippon Telegraph and Telephone Corporation 4. Agent Address: 160 Address: 7-5-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo (2) Whistle 2: 7th Floor, Mizota Building Column 6, “Detailed Description of the Invention” in the Specification, Contents of Amendment (1) Specification No. In the 6th to 5th lines from the bottom of page 7, ``are each...operated'' is corrected to ``is operated so that the room temperature and degree of superheating are adjusted to the set values, and the empty am is''. (2) Change the [compressor rotation speed and expansion valve opening degree] from the first line from the bottom of the same page to the first line from the bottom of the same page of the same book to [room temperature and superheat degree 1
and correct it. (3) "Compare with 1 on page 8, line 1 of the same book" to "match"
and correct it. (4) Add and correct [according to each setting value] next to "degree of superheating" on the 9th line of the same page.

Claims (1)

[Claims] A variable capacity compressor that is controlled by a compressor rotation speed control means that outputs a capacity control signal to the compressor based on the difference between a set room temperature and a detected room temperature by a room temperature setting means that sets the room temperature and a room temperature detection means that detects the room temperature. , an outdoor heat exchanger consisting of a condenser and an outdoor blower, and an expansion valve that outputs an opening control signal to the expansion valve based on the degree of superheat detected by the degree of superheat detection means that detects the degree of superheat at the inlet of the compressor. An indoor heat exchanger comprising a variable opening expansion valve controlled by an opening control means, and an indoor blower controlled by an indoor blower rotation speed control means that controls the rotation speed of the evaporator and the indoor blower. In an air conditioner that is connected sequentially to form a refrigeration cycle, a current value detection means for detecting a current value supplied to each of the compressor and the indoor blower is provided, and the rotation speed of the indoor blower is determined by the rotation speed of the indoor blower. If the sum of the respective current values detected by the current detection means of the compressor and the indoor blower increases after it is determined that the rotation speed of the inner blower has reached a steady state by changing a small amount by the inner blower rotation speed control means, the above-mentioned If the rotation speed of the indoor fan is slightly changed in the direction opposite to the direction in which it was slightly changed last time, and the sum of the current values decreases, the rotation speed of the indoor fan is changed in the direction in which it was slightly changed last time. A control method for an air conditioner characterized by making slight changes in the same direction.