JPH0429944B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multi-room heating and cooling system in which a plurality of indoor units are connected to one outdoor unit.

(Prior art) In conventionally known multi-room heating and cooling systems, when multiple indoor units are operated simultaneously, even if there is a difference in the load applied to each indoor unit, capacity control that corresponds to the difference in load is difficult. It had not been done. For this reason, light-load indoor units have the disadvantage of repeatedly starting and stopping, impairing comfort.
If you control the indoor unit's air volume (blower rotation speed) while ignoring the outdoor unit, you will force the compressor to operate under harsh conditions such as an abnormal rise in high pressure.
This resulted in increasing the cause of failures.

Furthermore, a system has already been proposed in which the air volume of an indoor unit is controlled based on the difference between the room temperature and the set temperature. Since it does not accurately indicate the indoor load, the above drawbacks cannot be completely eliminated. Furthermore, in the case of stopping an indoor unit, if the thermostat is used to start and stop, there will inevitably be a difference in the differential, which may lengthen the stopping time, leaving the problem of increased discomfort.

(Problems to be Solved by the Invention) The present invention has been made in an attempt to improve the problems pointed out in the above-mentioned section of the prior art. The rotational speed of the compressor motor is controlled to maintain a constant high pressure during heating, while the capacity of each indoor unit is controlled by controlling the rotation of the blower for each indoor unit whose room temperature approaches within a predetermined difference from the set value. This blower rotation speed control is performed by calculating the change in room temperature at fixed time intervals that can measure the difference between capacity and load, and increasing or decreasing the rotation speed in response to the change in room temperature. , even if the air volume of the indoor unit is set to the minimum,
When the room temperature reaches the set value, the air conditioning load is determined based on the magnitude of the change in the room temperature at that time, and the operation is stopped for a period of time corresponding to the magnitude of the load. The purpose is to obtain the most suitable operating pattern for the load.

(Means for Solving the Problems) As a means for achieving the above object, the present invention provides a multi-room air conditioning system in which an outdoor unit is equipped with a high-pressure pressure detector that operates during heating and a high-pressure sensor that operates during cooling. a low pressure pressure detector, a pressure setting means for setting upper and lower limits of each of high pressure and low pressure, and a prime mover rotation speed such that each of the high pressure during heating or the low pressure during cooling exceeds the lower limit value and is less than the upper limit. A prime mover rotation speed calculation means for calculating the rotation speed of the prime mover, and a prime mover rotation speed control means for controlling the rotation speed of the prime mover based on the calculation result of the prime mover rotation speed calculation means and the operation control output signal from each indoor unit are attached. The unit includes a room temperature detector, a room temperature setting device, a comparison means for comparing the room temperature with the set value, a room temperature change calculation means for calculating the change in the room temperature at fixed time intervals, and a room temperature setting device. In the case of an indoor unit in which the difference between the room temperature and the set value is within a predetermined value, there is a stop time calculation means that calculates the stop time by multiplying a predetermined constant by the change value. A blower rotation speed calculation means for calculating a blower rotation speed by calculating a correction value by multiplying a constant by a change value and adding or subtracting the correction value to the current rotation speed of the blower; and a calculation by the blower rotation speed calculation means. A rotation speed control means is provided for controlling the rotation speed of the blower based on the result and the signal from the stop time calculation means.

(Function) As described above, in the present invention, in a multi-room air conditioning system, the capacity of the entire system is controlled by controlling the rotational speed of the compressor prime mover, and the capacity of each indoor unit is controlled by a blower that corresponds to the rate of change in room temperature. By controlling the rotation speed of the air conditioner and controlling the blower stop time in accordance with the rate of change in room temperature, it is possible to control the operation in an operation pattern that is optimal for the air conditioning load at that time. This effect can be obtained.

(Embodiments) Hereinafter, some preferred embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 2, this air conditioning system is an outdoor air conditioner equipped with a compressor 1, a four-way switching valve 2, an outdoor heat exchanger 3, a heating expansion valve 4 with a check valve 5, a receiver 6, and an accumulator 7. Unit X, cooling expansion valve 8 with check valve 9, and indoor heat exchanger 1
A plurality of indoor units A, each equipped with
It is composed of B and C. In Figure 2,
The suffixes A, B, and C are attached to the reference numerals indicating the parts constituting each of the indoor units A, B, and C. Second
In the figure, reference numeral 11 is a cooling and heating solenoid valve, 12 is a heating solenoid valve, 13 and 14 are check valves, 15 is an outdoor blower, 16 is an indoor blower, 17 is a high-pressure pressure detector,
18 is a low-pressure pressure detector, 19 is a compressor electric motor such as a motor, and 20 is a room temperature detector.

FIG. 1 shows a first embodiment of a control device configured to control the operation of the heating and cooling device.

The pressure setting means 21 is for setting the upper and lower limits of high pressure during heating and low pressure during cooling, and is configured using the ROM of the microcomputer.
(read-on memory).

During cooling, the prime mover rotational speed calculation means 22 calculates that the rotational speed is increased when the set value is above the set value, and the rotational speed is decreased when the lower limit set value is below, so that the low pressure is between the upper limit set value and the lower limit set value. On the other hand, during heating,
In order for the high pressure to be between the upper limit set value and the lower limit set value, calculation is performed such that the rotation speed is decreased when the upper limit setting value is exceeded, and the rotation speed is increased when the lower limit set value is below.

The operation control output means 23 is connected to each indoor unit A,
Based on the signals from B and C, outputs for starting and stopping the prime mover and signals for driving patterns are output.

The prime mover rotational speed control means 24 amplifies and converts the calculation result of the prime mover rotational speed calculating means 22 into an output for driving the prime mover, and at the same time controls the system start/stop and solenoid valves etc. based on the output signal from the operation control output means 23. Performs switching control.

The above-mentioned high pressure and low pressure pressure detectors 17, 1
8, pressure setting means 21, prime mover rotation speed calculation means 2
2. The operation control output means 23 and the prime mover rotation speed control means 24 constitute an outdoor controller 25.

The pressure setting means 21 and the prime mover rotation speed calculation means 22 in the outdoor controller 25 are configured as functions of a one-chip microcomputer 26 shown in FIG.

The microcomputer 26 includes a ROM (read-on memory) 26a and a RAM (random memory) 26a.
access memory) 26b, input port 26c,
An output port 26d, a timer 26e, and a CPU (central processing unit) 26 are combined into one LSI.

The input data from the high voltage detector 17 and the low voltage detector 18 are sent to the multiplexer 27 and the A/
Microcomputer 25 via D converter 28
The operation command signals from the indoor units A, B, and C are input to the input port 26c via the input interface 29.
The output signal of the microcomputer 25 (the calculated value of the prime mover rotation speed and the operation control output from the room) is output from the output interface 30, and the calculated rotation speed value is used as a frequency command to the inverter 31. While input as a value, operation commands from indoors are input as operation control output means 23.
The signal is inputted to the control means 32 via. Here, the inverter 31 and the control means 32 act as the prime mover rotation speed control means 24.

In addition, in FIG. 1, the room temperature setting device 33 is A,
It is installed in each room B and C and is set and operated by the user. When the room temperature exceeds the set value (that is, when the room temperature exceeds the set value for cooling and exceeds the set value for heating), the comparison means 34 outputs a stop signal to the rotation speed control means 38, which will be described later, to adjust the set value. When the difference between the temperature and the temperature becomes less than a predetermined value (that is, when the room temperature approaches the set temperature), a rotation speed control signal is output to a blower rotation speed calculation means 37, which will be described later. The room temperature change calculating means 35 calculates the change from the room temperature (ie, the previous room temperature - the current room temperature) every time there is an input from the timer 26e. Note that the value set by the timer 26e is determined from experimental values to a value that does not cause hunting or the like. The stop time calculation means 36 calculates the stop time TA·Δt between the change Δt in the room temperature after the input of the stop signal from the comparison means 34 and a constant A determined based on the target room temperature control, capacity, etc. do. Air blower rotation speed calculation means 3
Step 7 calculates the fan rotation speed in a state where there is no change in room temperature (Δt≈0), that is, the capacity and load are in equilibrium. The rotation speed control means 38 increases the rotation speed command value from the blower rotation speed calculation means 37,
The output is converted into an output that allows the rotation speed of the blower 16 to be controlled by conversion or the like.

Each of the above elements, namely, room temperature detector 20, room temperature setting device 33, comparison means 34, room temperature change calculation means 3
5. The stop time calculation means 36, the blower rotation speed calculation means 37, and the rotation speed control means 38 constitute an indoor controller 39.

This indoor controller 39 is also controlled by the microcomputer 26 similarly to the outdoor controller 25.

In this case, as shown in FIG.
The input data from the room temperature setting device 33 is inputted to the input port 26c of the microcomputer 26 via the multiplexer 27 and the A/D converter 28, and the output signal of the microcomputer 26 is outputted from the output interface 30. On the other hand, the blower control means 3 is supplied via the blower control output 40.
8, and the other input to the operation control output means 23 on the outdoor side.

Next, the control operation of the multi-room air conditioning system according to the first embodiment will be explained with reference to the flowcharts of the outdoor controller and the indoor controller shown in FIGS. 5 and 6.

() Outdoor controller (see Figure 5) Sets the initial rotation speed of the prime mover 19 with the cooling operation command, outputs the initial rotation speed setting value for a predetermined period of time until completion of startup, and thereafter:
In order to prevent hunting, etc., data from the low pressure detector 18 is input at fixed time intervals (i.e., every N ₁ seconds), and if the low pressure is less than the lower limit set value LP ₁ , the current rotation speed command is input until the lower limit value is exceeded. Subtract 1 from the stored memory contents (in other words, decrease the number of revolutions). Conversely, if the upper limit setting value LP ₂ or higher, LP ₂
The current rotational speed command value is increased by 1 (in other words, the rotational speed is increased) until the rotational speed command value decreases to below. There is a dead zone between the upper limit set value ΔP ₂ and the lower limit set value ΔP ₁ (Fig. 5).
_S1 − _S11 ).

An operation command without a cooling operation command (that is, a heating operation command sets the initial rotation speed of the prime mover 19,
The initial rotation speed setting value is output for a predetermined period of time until the start is completed, and after that, data from the high pressure detector 17 is input at fixed time intervals (i.e., every N ₂ seconds), and the high pressure is If the upper limit set value HP is ₁ or more, the current rotation speed command value is subtracted by 1 until it falls below the upper limit value (in other words, the rotation speed is decreased).
Conversely, if the lower limit set value HP is ₂ or less, the current rotation speed command value is increased by 1 (in other words, the rotation speed is increased) until the lower limit value is exceeded. (S ₁₁ to _{S 11} in FIG. 5) () Indoor controller (see FIG. 6) The initial rotation speed N _M of the blower 16 is set by the operation command (stored in the memory M ₀ ). If the difference between the room temperature and the set value exceeds the predetermined value _ts , the fan rotation speed becomes the maximum rotation speed N _M (Fig. 6 S ₁ ~
_S10 ). When the difference between the room temperature and the set value is within a predetermined value t _s and when the room temperature ≠ the set value, the product of the change in room temperature ±Δt calculated at regular intervals and the predetermined constant A is calculated. As a correction value for the current rotation speed N ₀ (N ₀ is stored in M ₀ ), N = N ₀ ±
The rotation speed N resulting from the calculation of A・Δt is stored in the memory _M0 as the new current rotation speed, and is output as the rotation speed command value (Fig. 6).
_S12 - _S14 ). On the other hand, when the room temperature reaches the set value, if the current rotation speed N ₀ is not the minimum rotation speed N _L , the minimum rotation speed N _L is stored as the new current rotation speed and output as the rotation speed command value. ( _S15 to _S16 in Figure 6). Furthermore, when the current rotation speed N ₀ is the lowest rotation speed N _L , the stop time T _x =B・
Calculate Δt, set the stop time T _x in the stop timer, and output it as a stop signal (see Figure 6).
_S17 - _S18 ).

FIG. 7 shows a functional block diagram of a control device for a multi-room heating and cooling system according to a second embodiment of the present invention.

In this case, the outdoor controller 25 receives a determination means 41 for determining whether or not to correct the pressure set value based on the number of rotations of the blower from each indoor unit A, B, and C, and a signal from the determination means 41 to control the blower. A correction value calculation means 42 is provided for calculating a correction value for correcting the set pressure in accordance with the rotation speed, and
A start/stop control means 43 is provided for receiving a stop command from each of the indoor units A, B, and C and controlling the start/stop of the system so that at least one guide unit can continue operating.

The above set pressure correction is carried out by inputting the current rotational speed _N0 of the blower of each indoor unit A, B, C, as shown in the flowchart shown in FIG.
The blower rotation speed N ₀ of one of C is the first set value
If the pressure is higher than N _R , the set pressure is not corrected and the fan rotation speeds of all indoor units A, B, and C are set to N _0.
is less than the set value N _R , and even one of them is the second
If there is a rotational speed less than the set value _Ns , the set pressure value is corrected according to the rotational speed (Fig. 8 S ₁ ~
_S9 ).

In addition, as shown in the flowchart shown in Figure 9, the above operation control is performed when the number of indoor units A, B, and C in operation is one, and when the room temperature reaches a set value and a stop request is made, the currently stopped operation is performed. The indoor unit with the shortest stop time is selected, and if the stop time is less than a preset time of D minutes, the indoor unit that received the stop request is allowed to continue operating for D minutes, and the indoor unit is stopped. By stopping the two indoor units for which the stop request has been made, the number of system starts and stops is reduced ( _S1 to _S7 in FIG. 9).

Incidentally, if the entire stop time of the stopped indoor unit exceeds D minutes, the stop command is output as is.

A second upper limit value higher than the upper limit set value by the pressure setting means 21 in the above embodiment and a second lower limit value lower than the lower limit set value are provided so that the detected pressure is equal to or higher than the second upper limit value and equal to or lower than the lower limit value. In such cases, it is also possible to increase the speed of the motor rotational speed correction based on pressure.

Note that the rotation speed control of the indoor blower in the above embodiment may be either stepwise control or stepless control, and an engine may be used as the prime mover.
Further, in the above embodiment, a heating and cooling system for three rooms has been described, but it is of course applicable to systems for two rooms or four or more rooms.

(Effects of the Invention) As described above, according to the present invention, even if there is a difference in the load corresponding to each indoor unit A, B, C...
If the difference between the room temperature and the set value approaches a predetermined difference, the fan speed is controlled to balance the capacity load, so as long as the load does not fall below the minimum capacity value. The blower does not start or stop, which has the excellent effect of eliminating discomfort when the blower stops and reducing losses caused by the blower stopping.

In addition, even when the blower is controlled to start or stop when the load is below the minimum capacity, the stop time is determined according to the load at that time.
The stop time can be made as short as possible, and there is also the effect that the discomfort caused when the blower is stopped can be greatly reduced.

Furthermore, since the compressor capacity is controlled by controlling the rotation speed of the compressor motor in response to changes in pressure (high pressure during heating, low pressure during cooling), there is no risk of excessive high pressure (during heating) or freezing. It is possible to avoid operating at low pressures (during cooling), which would result in more efficient operation and improved reliability.

[Brief explanation of drawings]

FIG. 1 is a correspondence diagram of function realizing means of an operation control device for a multi-room air conditioning system according to a first embodiment of the present invention;
FIG. 2 is a system diagram of a multi-room air conditioning system according to an embodiment of the present invention, FIG. 3 is a block diagram of the outdoor controller in FIG. 1, and FIG. 4 is a block diagram of the indoor controller in FIG. 5 and 6 are flowcharts of the outdoor controller and the indoor controller, FIG. 7 is a diagram corresponding to the function realizing means of the operation control device for the multi-room air conditioning system according to the second embodiment of the present invention, and FIG. 8 and FIG. FIG. 9 is a flowchart when pressure correction and operation control are performed in the operation control device of FIG. 7. 1...Compressor, 3...Outdoor heat exchanger, 10...
Indoor heat exchanger, 16... Blower, 17... High pressure detector, 18... Low pressure detector, 19... Prime mover, 2
0... Room temperature detector, 21... Pressure setting means, 22
... Prime mover rotation speed calculation means, 23... Operation control output means, 24... Prime mover rotation speed control means, 33...
... Room temperature setting device, 34 ... Comparison means, 35 ... Room temperature change calculation means, 36 ... Stop time calculation means, 37
...Blower rotation speed calculation means, 38...Rotation speed control means, 41...Judgment means, 42...Correction value calculation means, 43...Start/stop control means, X...Outdoor unit, A, B, C... ...Indoor unit.

Claims (1)

[Claims] 1. One outdoor unit X having a compressor 1 and an outdoor heat exchanger 3 driven by a prime mover 19 whose rotation speed can be controlled, and a blower 1 whose rotation speed can be controlled.
6 and an indoor heat exchanger 10, the outdoor unit X is equipped with a high-pressure pressure detector 17 that acts during heating. , a low-pressure pressure detector 18 that operates during cooling, and a pressure setting means 21 that sets upper and lower limit values for high pressure and low pressure, respectively.
and prime mover rotation speed calculation means 22 for calculating the rotation speed of the prime mover 19 such that each of the high pressure during heating or the low pressure during cooling exceeds the lower limit value and is less than the upper limit value; and the prime mover rotation speed calculation means 22 A prime mover rotation speed control means 24 is provided for controlling the rotation speed of the prime mover 19 based on the calculation results and operation control output signals from the indoor units A, B, C, . . . , B, C... are equipped with a room temperature detector 20.
, a room temperature setting device 33, a comparison means 34 for comparing the room temperature with a set value, a room temperature change calculation means 35 for calculating a change value of the room temperature at fixed time intervals, and an indoor unit A whose room temperature has reached the set value. , B, C, . . . , a stop time calculation means 36 for calculating a stop time by multiplying a predetermined constant by the change value;
A correction value is calculated by multiplying a predetermined constant by a change value in B, C..., and the correction value is applied to the blower 16.
A blower rotation speed calculating means 37 calculates the blower rotation speed by adding or subtracting the current rotation speed of the blower, and the calculation result of the blower rotation speed calculation means 37 and the signal from the stop time calculation means 36 are used to calculate the rotation speed of the blower. Blower 1
6. A multi-room air-conditioning/heating device characterized in that a rotation speed control means 38 for controlling the rotation speed of 6 is attached. 2 Each indoor unit A,
A determining means 41 for determining whether or not to correct the pressure set value by the pressure setting means 21 based on the blower rotation speed calculated by the blower rotation speed calculating means 37 in B, C, . . . Correction value calculation means 42 that calculates a correction value based on a correction command
and a start/stop control means 43 for inputting the stop time of each indoor unit A, B, C, . . . and controlling the start/stop of the system. Device.