JPH07110165A - Air conditioner - Google Patents

Abstract

PURPOSE:To automatically, efficiently accomplish operating conditions under which the power consumption is minimized, by providing a controller with three kinds of arithmetic mechanisms which calculate the valve lift of a variable flow rate expansion valve, the revolution number of a variable capacity compressor, and a valve lift and revolution number at which the power consumption is minimized. CONSTITUTION:A controller 21 decides target values regarding the outlet temperature, etc., of a variable capacity compressor 1 in a outdoor unit through a decision mechanism 7. A valve lift of a variable flow rate expansion valve 4 in an indoor unit is calculated by a first arithmetic mechanism 10 so that the deviation between the decided target value and a detected value becomes smaller, and the valve lift of the variable flow race expansion valve 4 is controlled by a valve lift controller 16 corresponding to the output of the first arithmetic mechanism 10. A target value of room temperature is set by a room temperature setting device 12. A second arithmetic mechanism 15 calculates a revolution number of the variable capacity compressor 4 at which the deviation between the target value and the detected room temperature becomes smaller, and a revolution number controller 11 controls the revolution number of the variable capacity compressor 4 corresponding to the output of the second arithmetic mechanism 15. The valve lift and the revolution number are corrected by a third arithmetic mechanism 17 so that the power consumption is minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating / cooling cycle, and more particularly to an air conditioner suitable for controlling the rotational speed of a compressor and controlling the opening of an expansion valve.

[0002]

[Prior art]

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an air conditioner provided with a control means capable of directly controlling power consumption or coefficient of performance.

[0004]

In order to achieve the above object, an air conditioner according to the present invention is an outdoor unit having a variable capacity compressor having a variable rotation speed and an outdoor heat exchanger provided with an outdoor fan. Unit, an indoor unit having a variable flow expansion valve with variable opening and an indoor heat exchanger provided with an indoor fan, an indoor unit and an outdoor unit are sequentially connected to form a cooling and heating cycle, and at least one device In an air conditioner comprising control means for controlling power consumption, the control means comprises a mechanism for determining a target value of the discharge temperature or the discharge superheat degree of the variable capacity compressor, and a target value of the discharge temperature or the discharge superheat degree. Of the flow rate variable expansion valve so as to reduce the deviation from the detected discharge temperature or discharge superheat degree, and the flow rate variable expansion valve according to the output of the first calculation mechanism. Opening control to control the opening A room temperature setting device for setting a target value of the room temperature, a second calculation mechanism for calculating the number of revolutions of the variable capacity compressor so that the deviation between the set room temperature and the detected room temperature becomes small, The rotation speed controller for controlling the rotation speed of the variable capacity compressor according to the output of the calculation mechanism of No. 2 and the opening and the rotation speed determined by the respective calculations within the respective deviations within the predetermined range and the power consumption. And a third calculation mechanism for correcting so that the value becomes a minimum value.

An outdoor unit having a variable capacity compressor with a variable rotation speed and an outdoor heat exchanger with an outdoor fan, and an indoor heat exchange with a variable flow expansion valve with variable opening and an indoor fan. In an air conditioner comprising an indoor unit having an air conditioner, and a control unit that sequentially connects the indoor unit and the outdoor unit to form a cooling and heating cycle and controls the power consumption of at least one device, the control unit has a capability. A mechanism that determines the target value of the intake wetness or superheat of the variable compressor, and the flow rate to reduce the deviation between the target value of the intake wetness or superheat and the detected intake wetness or superheat. A first calculation mechanism for calculating the opening of the variable expansion valve;
The opening controller that controls the opening of the variable flow expansion valve according to the output of the calculation mechanism, the room temperature setter that sets the target value of the room temperature, and the deviation between the set room temperature and the detected room temperature is small. So as to calculate the rotation speed of the variable capacity compressor, a rotation speed controller for controlling the rotation speed of the variable capacity compressor according to the output of the second calculation mechanism, and It may be configured to include a third calculation mechanism that corrects the determined opening degree and the number of revolutions so that the respective deviations are within a predetermined range and the power consumption becomes the minimum value.

Further, each of the first arithmetic mechanism, the second arithmetic mechanism and the third arithmetic mechanism may be configured to use a digital computer.

Further, the control means may have a means for notifying that the power consumption has reached the minimum value.

[0008] The control means is the third power consumption related
It may be configured to have a unit that enables selection of whether or not to execute the arithmetic mechanism of.

Further, the control means may be configured to have means for monitoring power consumption by a power detector or a current detector.

Further, the control means may have a means for evaluating the power consumption of the product at the time of shipping the product to determine whether the product is acceptable or not.

Further, in the packaged air conditioner with an inverter, any one of the air conditioners is provided with at least a capillary, a sub heat exchanger, a bypass, an electromagnetic valve and a check valve.

[0012]

According to the present invention, the first feedback control for controlling the opening degree of the variable flow expansion valve by the first arithmetic mechanism so that the discharge temperature or the discharge superheat degree of the variable capacity compressor becomes the target value. The system is constructed. Further, the second calculation mechanism constitutes a second feedback control system for controlling the rotation speed of the variable capacity compressor so that the room temperature becomes the set value or the air conditioning capacity becomes the target value. Furthermore the third
The optimization mechanism that reduces the power consumption or increases the coefficient of performance under the constraint condition that the respective deviations do not deviate from the predetermined range by making use of the first and second feedback control systems The system is constructed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, an outdoor unit having a variable capacity compressor 1 having a variable rotation speed and an outdoor heat exchanger 5 provided with an outdoor fan 6, a variable flow expansion valve 4 having a variable opening and an indoor unit. An indoor unit having an indoor heat exchanger 2 provided with a fan 3 and a control unit 21 for sequentially connecting the indoor unit and the outdoor unit to form a cooling / heating cycle and controlling the power consumption of at least one device. In the air conditioner, the control unit 21 includes a mechanism 7 that determines a target value of the discharge temperature or the discharge superheat degree of the variable capacity compressor 1, a discharge temperature or a target value of the discharge superheat degree, and the detected discharge temperature or The first calculation mechanism 10 for calculating the opening of the variable flow expansion valve 4 so that the deviation from the discharge superheat degree becomes small, and the opening of the variable flow expansion valve 4 according to the output of the first calculation mechanism 10. Opening controller 1 to control
1, a room temperature setting device 12 for setting a target value of the room temperature, and a second calculation mechanism 15 for calculating the rotation speed of the variable capacity compressor 1 so that the deviation between the set room temperature and the detected room temperature becomes small. And a rotation speed controller 16 that controls the rotation speed of the variable capacity compressor 1 according to the output of the second calculation mechanism 15, and the deviations of the opening and the rotation speed determined by the respective calculations are predetermined. This is a configuration including a third calculation mechanism 17 that corrects the power consumption within the range so that the power consumption becomes the minimum value.

When heating the room, as shown by the arrow in FIG. 1, the high-temperature and high-pressure gas refrigerant discharged from the variable capacity compressor (compressor) 1 is sent to the indoor heat exchanger 2, where it is condensed. By doing so, the low-temperature suction air from the room is heated and the high-temperature discharge air is sent out by the indoor fan 3 to heat the room. The liquid refrigerant condensed here is sent to the outdoor heat exchanger 5, where it absorbs heat and evaporates to become a gas refrigerant, so that outdoor air is applied to the outdoor heat exchanger 5 by the outdoor fan 6. The low-temperature low-pressure gas refrigerant evaporated here returns to the compressor 1 via the four-way valve 22 and the accumulator 23 again to form a closed heating cycle. On the other hand, when cooling the room, the four-way valve 22 is switched to circulate the refrigerant in the opposite direction. Although the heating cycle shown in FIG. 1 will be described in the following embodiments, the cooling cycle can be configured in exactly the same manner. That is, it goes without saying that various modifications and improvements can be made to the components of the cooling / heating cycle itself and their connection without departing from the spirit of the present invention.

In the cooling / heating cycle shown in FIG. 1, the first feedback control system for controlling the discharge temperature or the discharge superheat degree of the compressor by the opening degree of the variable flow rate expansion valve (expansion valve) 4 is the discharge temperature or discharge. A mechanism 7 for determining the target value of the superheat degree, a detector 8 for detecting the discharge temperature or the discharge superheat degree of the compressor 1, a subtracter 9 for obtaining the deviation between these target values and the detected value, and this deviation are small. The first calculation mechanism 10 that determines the opening degree of the expansion valve 4 so as to be finally zero, and based on the calculation result, for example, if the target value is larger than the detected value, the opening degree of the expansion valve 4 And an opening controller 11 for adjusting the opening. Also,
The opening of the expansion valve 4 may be controlled so that the deviation between the target value of the intake wetness or the intake superheat of the compressor 1 and the detected intake wetness or the intake superheat is small. On the other hand, the second feedback control system for controlling the indoor air temperature or the air conditioning capacity of the indoor heat exchanger 2 by the rotation speed of the compressor 1 is the room temperature setting device 12 in which the user manually inputs the set value of the room temperature. , A temperature detector 13 for detecting the temperature of the intake air to the indoor heat exchanger 2, a subtractor 14 for obtaining the deviation between these set values and the detected value, and this deviation is made small and finally set to zero. Further, it comprises a second arithmetic mechanism 15 for determining the rotational speed of the compressor 1, and a rotational speed controller 16 for controlling the rotational speed of the compressor 1 based on the result of this arithmetic operation. In addition, the target value of the air conditioning capacity of the indoor heat exchanger is determined from the deviation between the set value of room temperature and the detected value of the indoor intake air temperature, and the intake air temperature and the blown air temperature to the indoor heat exchanger 2 are determined. It is also possible to control the opening degree of the expansion valve 4 so that the difference between the difference and the actual air-conditioning capacity determined by the air volume of the indoor fan is reduced and finally becomes zero. At this time, a temperature detector for detecting the temperature of blown air is provided.

The first and second operation mechanisms described above are often based on so-called PID operation based on proportional-integral-derivative operation. Further, since the cooling / heating cycle is closed, even if only the opening degree of the expansion valve 4 is adjusted as the operation amount, not only the discharge temperature or discharge superheat degree of the compressor 1 which is the control amount for this but also the indoor heat exchanger 2 The suction temperature, the suction temperature, and the air conditioning capacity are also affected. On the contrary, even if only the number of revolutions of the compressor 1 is adjusted as the operation amount, not only the intake temperature, the outlet temperature and the air conditioning capacity of the indoor heat exchanger 2 which are the control amounts for this but also the discharge temperature of the compressor 1 are controlled. Alternatively, the discharge superheat degree is also affected.
In consideration of these interferences, the first computing mechanism and the second computing mechanism mutually exchange information relating to the magnitude of the deviation and the magnitude of the manipulated variable in addition to the PID computation, and utilize this information in advance. It is effective to add a calculation for correcting each operation amount so as to reduce the interference of the control amount. For example, a proportional gain may be connected from the output of the second arithmetic mechanism 15 to the output of the first arithmetic mechanism 10, and the output of the first arithmetic mechanism 10 may be corrected by the output of the proportional gain.

According to the above two feedback control systems, control is performed to maintain a stable operating state of the compressor and achieve an air-conditioning environment that satisfies the user's room temperature setting, regardless of changes in indoor and outdoor temperature conditions. It is possible to satisfy the two required specifications for the means. However, in these two feedback control systems, nothing is known about the amount of power consumption required by the air conditioner. Therefore, there is a possibility that the vehicle is operating in a state of high power consumption. Therefore, an experiment was conducted to evaluate the power consumption, and when the combination of the two manipulated variables of the rotation speed of the compressor and the opening degree of the expansion valve was adjusted under the constraint that the two required specifications were satisfied, It has been found that the power changes, ie the power consumption can be minimized.

With reference to FIG. 2, the principle of minimization of power consumption by the third arithmetic mechanism will be described based on the result of this experiment. In the horizontal plane, coordinate axes showing the number of revolutions of the compressor and the opening of the expansion valve are taken as two manipulated variables. Perpendicular to this plane,
Take a coordinate axis that shows power consumption. The first calculation mechanism achieves the target value of the discharge temperature or the discharge superheat degree of the compressor by controlling the expansion valve to the opening degree vs, and at the same time, the second calculation mechanism achieves the room temperature set value set by the occupant or The target value of the air-conditioning capacity determined from this is the compressor rotation speed fs.
The starting point is the steady state s achieved by controlling The power consumption at this time is ws. If the rotational speed of the compressor and the opening degree of the expansion valve are slightly adjusted while maintaining this state, power consumption may decrease. This means that there are multiple combinations of the discharge temperature or discharge superheat degree of the same compressor, the rotation speed of the compressor and the opening degree of the expansion valve that realizes room temperature or air conditioning capacity, and there is a difference in power consumption between them. This is due to the basic characteristic of the air conditioner. Of these, the condition where the required specifications that the set value of the discharge temperature or discharge superheat of the compressor and the set value of the room temperature do not deviate by more than a predetermined range are satisfied, that is, the deviation between each set value and the detected value is Within the range C that does not deviate from the predetermined range, there is always a state a in which the power consumption is minimum. If it deviates from the predetermined range C as in the state b, an excessive load will be applied to the compressor, or heating will be overheated.

Therefore, in the third calculation mechanism, the target value of the discharge temperature or the discharge superheat degree of the compressor, the detected value of the discharge temperature or the discharge superheat degree, and the opening degree of the expansion valve determined by the first calculation mechanism are set. In addition to the information of the two feedback control systems such as the set value of room temperature or the target value of room conditioning capacity, the detected value of room temperature or the actual air conditioning capacity, and the rotation speed of the compressor determined by the second computing mechanism, The power detector 18 shown in FIG. 1 for detecting the power consumed by the compressor, or if the voltage is constant, the detection value of the current detector 18 is input. Then, the combination of the rotation speed of the compressor 1 and the opening degree of the expansion valve 4 is calculated to minimize the power consumption, and the adder 1
9 and the adder 20 correct these two manipulated variables.

FIG. 3 is a third diagram in which two manipulated variables are actually determined based on the principle shown in FIG. 2 so as to minimize power consumption.
3 is a flowchart showing an example of a calculation procedure of the calculation mechanism of FIG. In this calculation procedure, the first feedback control regarding the discharge temperature or the discharge superheat degree of the compressor and the second feedback control regarding the room temperature or the air conditioning capacity are completed, respectively, in order to make a correct determination regarding the state of the air conditioner and the power consumption. Then, the air conditioner is started in a stable steady state. This can be determined by the fact that the rate of change of the discharge temperature or discharge superheat of the compressor, which is the main control amount of the air conditioner, and the room temperature or the air conditioning capacity, that is, the magnitude of the change before and after a predetermined time is less than or equal to a predetermined amount. The magnitude of this change does not necessarily have to be zero. First, in this state, one or both of the rotation speed of the compressor and the opening degree of the expansion valve are corrected and changed by a predetermined amount according to a predetermined rule. Then, after that, a waiting time is provided for a predetermined time to wait for the air conditioner to reach a stable steady state again. When the air conditioner enters a steady state, the compressor discharge temperature or discharge superheat does not deviate from the target value, and the room temperature does not deviate from the set value, or the room conditioning capacity deviates from the target value. Determine if not. However, it is originally impossible to control these deviations to be completely zero, and there is no need to control them, and it is sufficient that the deviations fall within predetermined deviations.

Only when the respective control amounts are within the predetermined deviations from the target value or the set value, compared to before the two operation amounts, the rotational speed of the compressor and the opening degree of the expansion valve, are changed. Evaluate whether the power consumption has decreased. If the power consumption is reduced, it can be determined that the previous two changes in the operation amount were effective. And next, it is effective to adopt the rule that the change amount of the same operation amount as the change contents of the previous two operation amounts is adopted, and approach the state in which the power consumption is minimized from the same direction. Thus, the state in which the power consumption is minimized can be efficiently obtained in time. If the power consumption has not decreased, the change in the manipulated variable is not valid, and it is necessary to restore the original manipulated variable. Then, as will be described later, when the procedure for changing the operation amount according to a predetermined rule is completed, it is impossible to further reduce the power consumption, and it can be determined that the state is the state in which the power consumption is the minimum. However, when the procedure for changing the manipulated variable according to the predetermined rule is not completed, the procedure for changing the two manipulated variables according to the next rule to obtain a state in which the power consumption is further reduced is continued. To do. In this case, it is effective to adopt a rule that changes the amount of operation different from the previous two changes of the amount of operation, and approaches from a different direction to the state where the power consumption is minimized. By doing so, a state in which power consumption is minimized without omission is required.

FIGS. 4 and 5 show an example of a rule for changing two manipulated variables, using the same coordinates on the horizontal plane as in FIG. As shown in FIGS. 4 and 5, in the areas D and E surrounded by the solid lines, the discharge temperature and the discharge superheat of the compressor are the target values, the room temperature is the set value, or the air conditioning capacity is the target value. Shows the state of being controlled with a predetermined accuracy, and these control amounts must always be within this area unless the target value or the set value is changed. That is, the purpose of the control means is to efficiently obtain a combination of two manipulated variables within the ranges D and E so that the power consumption becomes smaller as much as possible. Moreover, this procedure must be simple and capable of maintaining stable operating conditions. FIG. 4 shows a method of sequentially changing one of the two manipulated variables by a predetermined amount. As shown in FIG. 4, the point s in the area D is a starting point where the initial control is completed. At this time, the manipulated variables are fs and vs, respectively. Here, first, only the rotation speed fs of the compressor is set to a predetermined amount Δ.
Only f is reduced to ft (arrow A ₁ ). This results in a state t in which the power consumption is reduced, and this state is assumed to be within the area D as shown in the figure. If the power consumption does not decrease, or if the power consumption deviates from the region D as shown in the figure, an attempt is made to decrease the opening degree vs of the expansion valve by a predetermined amount Δv (arrow B ₁ ). Next, in the state t, the rotational speed ft of the compressor is also decreased by the predetermined amount Δf (arrow A ₂ ). As a result, if the power consumption does not decrease or if the power consumption deviates from the area D as shown in the figure, the state t is restored. At this time, the manipulated variables are ft and vs, respectively. Then, next, the opening degree vs of the expansion valve is reduced by a predetermined amount Δv to va (arrow B ₂ ). As a result, the power consumption is reduced to the state a, and this state is within the area D. If the power consumption does not decrease or if the power consumption deviates from the area D, the original state t is restored. Then, it is determined that this state is the state in which the power consumption is the minimum, and such a procedure is ended. Next, in the state a, the opening degree va of the expansion valve is also decreased by the predetermined amount Δv (arrow B ₃ ). If the power consumption is not reduced by this, or if the power consumption deviates from the region D, the original state a is restored. Then, the rotational speed fa of the compressor is reduced by a predetermined amount Δf (arrow A ₃ ). If the power consumption is not reduced by this, or if the power consumption deviates from the region D, the original state a is restored. Then, it is determined that this state a is the state in which the power consumption is the minimum, and such a procedure is ended.

Although FIG. 4 shows the procedure for individually changing each of the two manipulated variables by a predetermined amount, as shown in FIG.
A procedure of simultaneously changing two operation amounts by a predetermined amount is also conceivable. Also in FIG. 5, it is possible to obtain the state a in which the power consumption is minimized starting from the first state s by the same procedure as in FIG.

[0024]

[0025]

According to the present invention, when the control means is provided with three arithmetic mechanisms to control the opening of the expansion valve and the rotational speed of the compressor, an operating state in which power consumption is minimized is automatically set. Can be realized efficiently and efficiently, the highly efficient operation state is always maintained, and the effect of energy saving is extremely large.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a graph illustrating the principle of this embodiment.

FIG. 3 is a flowchart showing a procedure of operation of the present embodiment.

FIG. 4 is a graph illustrating the contents of control operation of the present embodiment.

FIG. 5 is a graph illustrating the contents of control operation of the present embodiment.

FIG. 6 is a diagram illustrating a combination of manipulated variables in the present embodiment.

[Explanation of symbols]

1 variable capacity compressor 2 indoor heat exchanger 3 indoor fan 4 variable flow expansion valve 5 outdoor heat exchanger 6 outdoor fan 7 mechanism for determining target value of discharge temperature or discharge superheat degree 10 first calculation mechanism 11 rotational speed control Device 12 Room temperature setting device 15 Second calculation mechanism 16 Opening controller 17 Third calculation mechanism 21 Control means

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[Procedure amendment]

[Submission date] October 19, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title of the invention Air conditioner

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating / cooling cycle, and more particularly to an air conditioner suitable for controlling the rotational speed of a compressor and controlling the opening of an expansion valve.

[0002]

2. Description of the Related Art A conventional air conditioner is disclosed in
63-25446 and JP-A-5-118609.
The technology described in the publication can be cited as an example. former
In the prior art, the compressor speed is controlled to control the room temperature and
Operate the opening of the expansion valve to set the degree of superheat of the compressor.
In addition to controlling to a fixed value or target value,
Operate the rotation speed of the blower to minimize power consumption.
It is characterized by.

[0003]

The object of the invention is to be Solved by the conventional air conditioning apparatus
In that case, the direct purpose of control is to set the room temperature and the compressor.
Stable control is to comply with the target value of superheat of
It has only the function to perform. And the ventilation on the indoor side
Is power consumption minimized by operating only the machine speed?
There is a limit to the minimization of power consumption. That is, truly
The power consumed by the entire air conditioner is not minimized.
However, there is an inconvenient problem from the viewpoint of energy saving.
there were.

An object of the present invention is to reduce power consumption or performance.
Air conditioning with control means that can control the number directly
To provide a summing device.

[0005]

In order to achieve the above object, an air conditioner according to the present invention is an outdoor unit having a variable capacity compressor having a variable rotation speed and an outdoor heat exchanger provided with an outdoor fan. Unit, an indoor unit having a variable flow expansion valve with variable opening and an indoor heat exchanger provided with an indoor fan, an indoor unit and an outdoor unit are sequentially connected to form a cooling and heating cycle, and at least one device In an air conditioner comprising control means for controlling power consumption, the control means comprises a mechanism for determining a target value of the discharge temperature or the discharge superheat degree of the variable capacity compressor, and a target value of the discharge temperature or the discharge superheat degree. Of the flow rate variable expansion valve so as to reduce the deviation from the detected discharge temperature or discharge superheat degree, and the flow rate variable expansion valve according to the output of the first calculation mechanism. Opening control to control the opening A room temperature setting device for setting a target value of the room temperature, a second calculation mechanism for calculating the number of revolutions of the variable capacity compressor so that the deviation between the set room temperature and the detected room temperature becomes small, The rotation speed controller for controlling the rotation speed of the variable capacity compressor according to the output of the calculation mechanism of No. 2 and the opening and the rotation speed determined by the respective calculations within the respective deviations within the predetermined range and the power consumption. And a third calculation mechanism for correcting so that the value becomes a minimum value.

An outdoor unit having a variable capacity compressor with a variable rotation speed and an outdoor heat exchanger with an outdoor fan, and an indoor heat exchange with a variable flow expansion valve with variable opening and an indoor fan. In an air conditioner comprising an indoor unit having an air conditioner, and a control unit that sequentially connects the indoor unit and the outdoor unit to form a cooling and heating cycle and controls the power consumption of at least one device, the control unit has a capability. A mechanism that determines the target value of the intake wetness or superheat of the variable compressor, and the flow rate to reduce the deviation between the target value of the intake wetness or superheat and the detected intake wetness or superheat. A first calculation mechanism for calculating the opening of the variable expansion valve;
The opening controller that controls the opening of the variable flow expansion valve according to the output of the calculation mechanism, the room temperature setter that sets the target value of the room temperature, and the deviation between the set room temperature and the detected room temperature is small. So as to calculate the rotation speed of the variable capacity compressor, a rotation speed controller for controlling the rotation speed of the variable capacity compressor according to the output of the second calculation mechanism, and It may be configured to include a third calculation mechanism that corrects the determined opening degree and the number of revolutions so that the respective deviations are within a predetermined range and the power consumption becomes the minimum value.

Further, each of the first computing mechanism, the second computing mechanism and the third computing mechanism may use a digital computer.

Further, the control means may have a means for notifying that the power consumption has reached the minimum value.

Then, the control means is the third device related to power consumption.
It may be configured to have a unit that enables selection of whether or not to execute the arithmetic mechanism of.

Further, the control means may have a structure having means for monitoring power consumption by a power detector or a current detector.

Further, the control means may have a means for evaluating the power consumption of the product at the time of shipping the product to determine whether the product is acceptable or not.

In the packaged air conditioner with an inverter, any one of the air conditioners is provided with at least a capillary, a sub heat exchanger, a bypass, a solenoid valve and a check valve.

[0013]

According to the present invention, the first feedback control for controlling the opening degree of the variable flow expansion valve by the first arithmetic mechanism so that the discharge temperature or the discharge superheat degree of the variable capacity compressor becomes the target value. The system is constructed. Further, the second calculation mechanism constitutes a second feedback control system for controlling the rotation speed of the variable capacity compressor so that the room temperature becomes the set value or the air conditioning capacity becomes the target value. Furthermore the third
The optimization mechanism that reduces the power consumption or increases the coefficient of performance under the constraint condition that the respective deviations do not deviate from the predetermined range by making use of the first and second feedback control systems The system is constructed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, an outdoor unit having a variable capacity compressor 1 having a variable rotation speed and an outdoor heat exchanger 5 provided with an outdoor fan 6, a variable flow expansion valve 4 having a variable opening and an indoor unit. An indoor unit having an indoor heat exchanger 2 provided with a fan 3 and a control unit 21 for sequentially connecting the indoor unit and the outdoor unit to form a cooling / heating cycle and controlling the power consumption of at least one device. In the air conditioner, the control unit 21 includes a mechanism 7 that determines a target value of the discharge temperature or the discharge superheat degree of the variable capacity compressor 1, a discharge temperature or a target value of the discharge superheat degree, and the detected discharge temperature or The first calculation mechanism 10 for calculating the opening of the variable flow expansion valve 4 so that the deviation from the discharge superheat degree becomes small, and the opening of the variable flow expansion valve 4 according to the output of the first calculation mechanism 10. Opening controller 1 to control
1, a room temperature setting device 12 for setting a target value of the room temperature, and a second calculation mechanism 15 for calculating the rotation speed of the variable capacity compressor 1 so that the deviation between the set room temperature and the detected room temperature becomes small. And a rotation speed controller 16 that controls the rotation speed of the variable capacity compressor 1 according to the output of the second calculation mechanism 15, and the deviations of the opening and the rotation speed determined by the respective calculations are predetermined. This is a configuration including a third calculation mechanism 17 that corrects the power consumption within the range so that the power consumption becomes the minimum value.

When heating the room, as shown by the arrow in FIG. 1, the high-temperature and high-pressure gas refrigerant discharged from the variable capacity compressor (compressor) 1 is sent to the indoor heat exchanger 2 where it is condensed. By doing so, the low-temperature suction air from the room is heated and the high-temperature discharge air is sent out by the indoor fan 3 to heat the room. The liquid refrigerant condensed here is sent to the outdoor heat exchanger 5, where it absorbs heat and evaporates to become a gas refrigerant, so that outdoor air is applied to the outdoor heat exchanger 5 by the outdoor fan 6. The low-temperature low-pressure gas refrigerant evaporated here returns to the compressor 1 via the four-way valve 22 and the accumulator 23 again to form a closed heating cycle. On the other hand, when cooling the room, the four-way valve 22 is switched to circulate the refrigerant in the opposite direction. Although the heating cycle shown in FIG. 1 will be described in the following embodiments, the cooling cycle can be configured in exactly the same manner. That is, it goes without saying that various modifications and improvements can be made to the components of the cooling / heating cycle itself and their connection without departing from the spirit of the present invention.

In the cooling and heating cycle shown in FIG. 1, the first feedback control system for controlling the discharge temperature or the discharge superheat of the compressor by the opening degree of the variable flow rate expansion valve (expansion valve) 4 is the discharge temperature or the discharge. A mechanism 7 for determining the target value of the superheat degree, a detector 8 for detecting the discharge temperature or the discharge superheat degree of the compressor 1, a subtracter 9 for obtaining the deviation between these target values and the detected value, and this deviation are small. The first calculation mechanism 10 that determines the opening degree of the expansion valve 4 so as to be finally zero, and based on the calculation result, for example, if the target value is larger than the detected value, the opening degree of the expansion valve 4 And an opening controller 11 for adjusting the opening. Also,
The opening of the expansion valve 4 may be controlled so that the deviation between the target value of the intake wetness or the intake superheat of the compressor 1 and the detected intake wetness or the intake superheat is small. On the other hand, the second feedback control system for controlling the indoor air temperature or the air conditioning capacity of the indoor heat exchanger 2 by the rotation speed of the compressor 1 is the room temperature setting device 12 in which the user manually inputs the set value of the room temperature. , A temperature detector 13 for detecting the temperature of the intake air to the indoor heat exchanger 2, a subtractor 14 for obtaining the deviation between these set values and the detected value, and this deviation is made small and finally set to zero. Further, it comprises a second arithmetic mechanism 15 for determining the rotational speed of the compressor 1, and a rotational speed controller 16 for controlling the rotational speed of the compressor 1 based on the result of this arithmetic operation. In addition, the target value of the air conditioning capacity of the indoor heat exchanger is determined from the deviation between the set value of room temperature and the detected value of the indoor intake air temperature, and the intake air temperature and the blown air temperature to the indoor heat exchanger 2 are determined. It is also possible to control the opening degree of the expansion valve 4 so that the difference between the difference and the actual air-conditioning capacity determined by the air volume of the indoor fan is reduced and finally becomes zero. At this time, a temperature detector for detecting the temperature of blown air is provided.

The first and second arithmetic mechanisms described above are often based on so-called PID arithmetic based on proportional-integral-derivative arithmetic. Further, since the cooling / heating cycle is closed, even if only the opening degree of the expansion valve 4 is adjusted as the operation amount, not only the discharge temperature or discharge superheat degree of the compressor 1 which is the control amount for this but also the indoor heat exchanger 2 The suction temperature, the suction temperature, and the air conditioning capacity are also affected. On the contrary, even if only the number of revolutions of the compressor 1 is adjusted as the operation amount, not only the intake temperature, the outlet temperature and the air conditioning capacity of the indoor heat exchanger 2 which are the control amounts for this but also the discharge temperature of the compressor 1 are controlled. Alternatively, the discharge superheat degree is also affected.
In consideration of these interferences, the first computing mechanism and the second computing mechanism mutually exchange information relating to the magnitude of the deviation and the magnitude of the manipulated variable in addition to the PID computation, and utilize this information in advance. It is effective to add a calculation for correcting each operation amount so as to reduce the interference of the control amount. For example, a proportional gain may be connected from the output of the second arithmetic mechanism 15 to the output of the first arithmetic mechanism 10, and the output of the first arithmetic mechanism 10 may be corrected by the output of the proportional gain.

According to the above two feedback control systems, control is performed to maintain a stable operating state of the compressor and achieve an air-conditioning environment that satisfies the user's room temperature setting, regardless of fluctuations in indoor and outdoor temperature conditions. It is possible to satisfy the two required specifications for the means. However, in these two feedback control systems, nothing is known about the amount of power consumption required by the air conditioner. Therefore, there is a possibility that the vehicle is operating in a state of high power consumption. Therefore, an experiment was conducted to evaluate the power consumption, and when the combination of the two manipulated variables of the rotation speed of the compressor and the opening degree of the expansion valve was adjusted under the constraint that the two required specifications were satisfied, It has been found that the power changes, ie the power consumption can be minimized.

With reference to FIG. 2, the principle of the minimization of power consumption by the third arithmetic mechanism will be described based on the result of this experiment. In the horizontal plane, coordinate axes showing the number of revolutions of the compressor and the opening of the expansion valve are taken as two manipulated variables. Perpendicular to this plane,
Take a coordinate axis that shows power consumption. The first calculation mechanism achieves the target value of the discharge temperature or the discharge superheat degree of the compressor by controlling the expansion valve to the opening degree vs, and at the same time, the second calculation mechanism achieves the room temperature set value set by the occupant or The target value of the air-conditioning capacity determined from this is the compressor rotation speed fs.
The starting point is the steady state s achieved by controlling The power consumption at this time is ws. If the rotational speed of the compressor and the opening degree of the expansion valve are slightly adjusted while maintaining this state, power consumption may decrease. This means that there are multiple combinations of the discharge temperature or discharge superheat degree of the same compressor, the rotation speed of the compressor and the opening degree of the expansion valve that realizes room temperature or air conditioning capacity, and there is a difference in power consumption between them. This is due to the basic characteristic of the air conditioner. Of these, the condition where the required specifications that the set value of the discharge temperature or discharge superheat of the compressor and the set value of the room temperature do not deviate by more than a predetermined range are satisfied, that is, the deviation between each set value and the detected value is Within the range C that does not deviate from the predetermined range, there is always a state a in which the power consumption is minimum. If it deviates from the predetermined range C as in the state b, an excessive load will be applied to the compressor, or heating will be overheated.

Therefore, in the third calculation mechanism, the target value of the discharge temperature or the discharge superheat degree of the compressor, the detected value of the discharge temperature or the discharge superheat degree, and the opening degree of the expansion valve determined by the first calculation mechanism. In addition to the information of the two feedback control systems such as the set value of room temperature or the target value of room conditioning capacity, the detected value of room temperature or the actual air conditioning capacity, and the rotation speed of the compressor determined by the second computing mechanism, The power detector 18 shown in FIG. 1 for detecting the power consumed by the compressor, or if the voltage is constant, the detection value of the current detector 18 is input. Then, the combination of the rotation speed of the compressor 1 and the opening degree of the expansion valve 4 is calculated to minimize the power consumption, and the adder 1
9 and the adder 20 correct these two manipulated variables.

FIG. 3 is a third diagram in which two operation amounts are actually determined based on the principle shown in FIG. 2 so that the power consumption is minimized.
3 is a flowchart showing an example of a calculation procedure of the calculation mechanism of FIG. In this calculation procedure, the first feedback control regarding the discharge temperature or the discharge superheat degree of the compressor and the second feedback control regarding the room temperature or the air conditioning capacity are completed, respectively, in order to make a correct determination regarding the state of the air conditioner and the power consumption. Then, the air conditioner is started in a stable steady state. This can be determined by the fact that the rate of change of the discharge temperature or discharge superheat of the compressor, which is the main control amount of the air conditioner, and the room temperature or the air conditioning capacity, that is, the magnitude of the change before and after a predetermined time is less than or equal to a predetermined amount. The magnitude of this change does not necessarily have to be zero. First, in this state, one or both of the rotation speed of the compressor and the opening degree of the expansion valve are corrected and changed by a predetermined amount according to a predetermined rule. Then, after that, a waiting time is provided for a predetermined time to wait for the air conditioner to reach a stable steady state again. When the air conditioner enters a steady state, the compressor discharge temperature or discharge superheat does not deviate from the target value, and the room temperature does not deviate from the set value, or the room conditioning capacity deviates from the target value. Determine if not. However, it is originally impossible to control these deviations to be completely zero, and there is no need to control them, and it is sufficient that the deviations fall within predetermined deviations.

Only when the respective control amounts are within a predetermined deviation from the target value or the set value, compared to before changing the two operation amounts, the rotational speed of the compressor and the opening degree of the expansion valve. Evaluate whether the power consumption has decreased. If the power consumption is reduced, it can be determined that the previous two changes in the operation amount were effective. And next, it is effective to adopt the rule that the change amount of the same operation amount as the change contents of the previous two operation amounts is adopted, and approach the state in which the power consumption is minimized from the same direction. Thus, the state in which the power consumption is minimized can be efficiently obtained in time. If the power consumption has not decreased, the change in the manipulated variable is not valid, and it is necessary to restore the original manipulated variable. Then, as will be described later, when the procedure for changing the operation amount according to a predetermined rule is completed, it is impossible to further reduce the power consumption, and it can be determined that the state is the state in which the power consumption is the minimum. However, when the procedure for changing the manipulated variable according to the predetermined rule is not completed, the procedure for changing the two manipulated variables according to the next rule to obtain a state in which the power consumption is further reduced is continued. To do. In this case, it is effective to adopt a rule that changes the amount of operation different from the previous two changes of the amount of operation, and approaches from a different direction to the state where the power consumption is minimized. By doing so, a state in which power consumption is minimized without omission is required.

4 and 5 show an example of a rule for changing two manipulated variables, using the same horizontal plane coordinates as in FIG. As shown in FIGS. 4 and 5, in the areas D and E surrounded by the solid lines, the discharge temperature and the discharge superheat of the compressor are the target values, the room temperature is the set value, or the air conditioning capacity is the target value. Shows the state of being controlled with a predetermined accuracy, and these control amounts must always be within this area unless the target value or the set value is changed. That is, the purpose of the control means is to efficiently obtain a combination of two manipulated variables within the ranges D and E so that the power consumption becomes smaller as much as possible. Moreover, this procedure must be simple and capable of maintaining stable operating conditions. FIG. 4 shows a method of sequentially changing one of the two manipulated variables by a predetermined amount. As shown in FIG. 4, the point s in the area D is a starting point where the initial control is completed. At this time, the manipulated variables are fs and vs, respectively. Here, first, only the rotation speed fs of the compressor is set to a predetermined amount Δ.
Only f is reduced to ft (arrow A ₁ ). This results in a state t in which the power consumption is reduced, and this state is assumed to be within the area D as shown in the figure. If the power consumption does not decrease, or if the power consumption deviates from the region D as shown in the figure, an attempt is made to decrease the opening degree vs of the expansion valve by a predetermined amount Δv (arrow B ₁ ). Next, in the state t, the rotational speed ft of the compressor is also decreased by the predetermined amount Δf (arrow A ₂ ). As a result, if the power consumption does not decrease or if the power consumption deviates from the area D as shown in the figure, the state t is restored. At this time, the manipulated variables are ft and vs, respectively. Then, next, the opening degree vs of the expansion valve is reduced by a predetermined amount Δv to va (arrow B ₂ ). As a result, the power consumption is reduced to the state a, and this state is in the area D as shown in the figure . If the power consumption does not decrease or if the power consumption deviates from the area D, the original state t is restored. Then, it is determined that this state is the state in which the power consumption is the minimum, and such a procedure is ended. Next, in the state a, the opening degree va of the expansion valve is also set to the predetermined amount Δv.
Only (arrow B ₃ ). If the power consumption is not reduced by this, or if the power consumption deviates from the region D, the original state a is restored. Then, the rotational speed fa of the compressor is reduced by a predetermined amount Δf (arrow A ₃ ). If the power consumption is not reduced by this, or if the power consumption deviates from the region D, the original state a is restored. Then, it is determined that this state a is the state in which the power consumption is the minimum, and such a procedure is ended.

Although FIG. 4 shows the procedure for individually changing each of the two manipulated variables by a predetermined amount, as shown in FIG.
A procedure of simultaneously changing two operation amounts by a predetermined amount is also conceivable. Also in FIG. 5, it is possible to obtain the state a in which the power consumption is minimized starting from the first state s by the same procedure as in FIG.

In practice, details of such a procedure can be found in air conditioning equipment.
The operation test of the equipment can be specified in advance in a concrete and quantitative manner.
Wear. Further, based on this result, as shown in FIG.
In addition, there are two types that can achieve the state of the minimum power consumption.
Predetermine and memorize the combination of the operation amount of
The number of revolutions of the compressor corresponding to the set value and the target value of the discharge temperature
And it becomes possible to select the opening degree of the expansion valve. Of course Figure 6
The states not shown in Fig. 6 are supplemented by the other values shown in Fig. 6.
Just ask in between. By doing this,
The decision can be made in a short time. In addition, in FIG.
As a starting point, the procedure shown in FIGS.
It can also be applied and this method is more efficient in time.
Power consumption may be minimized.

Further , even if this third arithmetic mechanism is not provided,
The two original feedback control mechanisms of the control means are damaged.
There is no need to minimize this power consumption
When it is possible, the judgment of the user or the judgment of the control means itself
You can stop or pause it by disconnecting
It

In the present invention, the power consumption is minimized.
I explained it for the purpose of
(COP) and maximizing energy efficiency
You may use it.

These are calculated by the ratio of air conditioning output and power consumption.
Will be the same.

The entire control means 21 shown in FIG .
It is effective to configure the
Noh can be easily configured by software.
Better than that. In addition, the control means 21 is
Power consumption has been minimized.
Is a means to inform the outside and whether to execute the calculation of power consumption
Means, power detector or current detector to enable selection
To monitor the power consumption by the device and when shipping the product
A means to evaluate the power consumption of the product and judge pass / fail
It can be equipped. In addition, as an air conditioner,
Capillary, sub heat exchanger, bypass, solenoid valve and check
Inverter package air conditioner with valve
May be

[0030]

According to the present invention, when the control means is provided with three arithmetic mechanisms to control the opening of the expansion valve and the rotational speed of the compressor, an operating state in which power consumption is minimized is automatically set. Can be realized efficiently and efficiently, the highly efficient operation state is always maintained, and the effect of energy saving is extremely large.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a graph illustrating the principle of this embodiment.

FIG. 3 is a flowchart showing a procedure of operation of the present embodiment.

FIG. 4 is a graph illustrating the contents of control operation of the present embodiment.

FIG. 5 is a graph illustrating the contents of control operation of the present embodiment.

FIG. 6 is a diagram illustrating a combination of manipulated variables in the present embodiment.

[Explanation of symbols] 1 variable capacity compressor 2 indoor heat exchanger 3 indoor fan 4 variable flow expansion valve 5 outdoor heat exchanger 6 outdoor fan 7 mechanism for determining target value of discharge temperature or discharge superheat 10 first calculation Mechanism 11 Rotation speed controller 12 Room temperature setting device 15 Second computing mechanism 16 Opening controller 17 Third computing mechanism 21 Control means

Claims (8)

[Claims] 1. An outdoor unit having a variable capacity compressor whose rotation speed is variable and an outdoor heat exchanger provided with an outdoor fan,
An indoor unit having a variable flow expansion valve with a variable opening and an indoor heat exchanger provided with an indoor fan, and the indoor unit and the outdoor unit are sequentially connected to form a cooling and heating cycle and consumption of at least one device In an air conditioner comprising control means for controlling electric power, the control means comprises a mechanism for determining a target value of a discharge temperature or a discharge superheat degree of the variable capacity compressor, and the discharge temperature or the discharge superheat degree. According to the output of the first calculation mechanism for calculating the opening of the flow rate variable expansion valve so that the deviation between the target value of V and the detected discharge temperature or the degree of discharge superheat becomes small. An opening controller that controls the opening of the variable flow expansion valve, a room temperature setting device that sets a target value of room temperature, and the capacity variable so that the deviation between the set room temperature and the detected room temperature becomes small. Calculate the rotation speed of the compressor A second calculation mechanism; a rotation speed controller for controlling the rotation speed of the variable capacity compressor according to the output of the second calculation mechanism; and the opening degree and the rotation speed determined by the respective calculations. An air conditioning apparatus comprising: a third calculation mechanism that corrects each deviation so that the power consumption becomes a minimum value within a predetermined range. 2. An outdoor unit having a variable capacity compressor whose rotation speed is variable and an outdoor heat exchanger provided with an outdoor fan,
An indoor unit having a variable flow expansion valve with a variable opening and an indoor heat exchanger provided with an indoor fan, and the indoor unit and the outdoor unit are sequentially connected to form a cooling and heating cycle and consumption of at least one device In an air conditioner comprising control means for controlling electric power, the control means comprises a mechanism for determining a target value of intake wetness or intake superheat of the variable capacity compressor, and the intake wetness or intake superheat. Calculation unit for calculating the opening of the flow rate variable expansion valve so that the deviation between the target value of the flow rate and the detected intake wetness or superheat is detected, and the output of the first calculation unit Accordingly, an opening controller for controlling the opening of the variable flow expansion valve, a room temperature setting device for setting a target value of room temperature, and the above-mentioned so as to reduce the deviation between the set room temperature and the detected room temperature. Calculates the rotation speed of the variable capacity compressor A second calculation mechanism, a rotation speed controller for controlling the rotation speed of the variable capacity compressor according to the output of the second calculation mechanism, and the opening degree and the rotation speed determined by the respective calculations. And a third calculation mechanism that corrects each deviation so that the deviation is within a predetermined range and the power consumption becomes the minimum value. 3. The air conditioner according to claim 1 or 2, wherein each of the first computing mechanism, the second computing mechanism and the third computing mechanism uses a digital computer. Harmony device. 4. The air conditioner according to claim 1 or 2, wherein the control means has means for notifying that the power consumption has reached a minimum value. 5. The air conditioner according to claim 1 or 2, wherein the control means has means for enabling selection of whether or not to execute the third calculation mechanism for power consumption. Air conditioner. 6. The air conditioner according to claim 1 or 2, wherein the control means has means for monitoring power consumption by a power detector or a current detector. 7. The air conditioner according to claim 1 or 2, wherein the control means has means for evaluating the power consumption of the product at the time of shipping the product to determine pass / fail. Air conditioner that does. 8. The air conditioner according to claim 1, further comprising at least a capillary, a sub heat exchanger, a bypass, a solenoid valve and a check valve. Package air conditioner.