JPH0261466A - Operation control device of air conditioning apparatus - Google Patents

Abstract

PURPOSE:To make the operation of a compressor in compression capacity controllable according to the vaporization pressure during the cooling operation, when the controlled value is set for the operative capacity of the compressor, by making a correction taking pressure loss and the like into consideration. CONSTITUTION:A correction taking pressure loss and the like into consideration is made in setting the controlled value for the operative capacity of the compres sor 1 according to the capacity requirements from each of indoor units. That is to say, the required capacity for the vaporization is corrected on the basis of the capacity in use for the vaporization at the time at the heat exchanger 7 as the user so that the corrected value is used as the requirement for the control of the operation of the compressor 1 in capacity. Thus, independent of pressure loss at the intervening pipe, the control is effected to supply an actual vaporization pressure required. It does not occur, therefore, for a heat exchanger using the pressure to be insufficient in capacity due to pressure loss and the like.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to an operation control device for an air conditioner equipped with a variable capacity compressor, and in particular controls the operating capacity of the compressor according to the evaporation pressure during cooling operation. Concerning improvements to things that are controlled.

(Prior art) Conventionally, in an air conditioner equipped with a variable capacity compressor, during cooling operation, a user-side heat exchanger is used between the suction gas pressure (low pressure) in the suction pipe of the compressor and the operating capacity of the compressor. This operation attempts to secure the amount of refrigerant circulation necessary for the heat exchange capacity required by the heat exchanger on the user side by estimating the evaporation pressure of the air and controlling the operating capacity of the compressor based on the estimated evaporation pressure. The control device is a known technology.

(Problem to be Solved by the Invention) However, in the above conventional system, the detected evaporation pressure is a physical state quantity of the refrigerant that has already suffered a pressure loss in the piping from the utilization side heat exchanger to the compressor. It cannot necessarily be said that the evaporation pressure in the user-side heat exchanger, which should be the true control target, is accurately reflected.

In particular, in the case of a multi-way air conditioner in which multiple indoor units are connected in parallel to an outdoor unit, the piping length is generally long, and the length may vary depending on the position of the indoor unit. However, there is a problem in that the deviation between the target evaporation pressure and the actual evaporation pressure is large, which tends to lead to insufficient operating capacity of the compressor.

The present invention has been made in view of the above, and its purpose is to make corrections that take into account pressure loss, etc. when determining a control target value for controlling the operating capacity of a compressor according to the required capacity of each indoor unit. By doing so, the purpose is to improve the accuracy of capacity control and thereby eliminate capacity shortages.

(Means for Solving the Problems) In order to achieve the above object, the first solution of the present invention is as shown in FIG. , pressure reduction mechanism (6) and user side heat exchanger (
The present invention is directed to an air conditioner equipped with a refrigerant circuit (12) connected to 7).

Then, during cooling operation, a required capacity detection means (T h1) for detecting the required indoor evaporation capacity, and the above-mentioned utilization side heat exchanger (
7), which detects the evaporation pressure of the refrigerant;
) for correcting the required evaporation capacity detected by the required capacity detection means (Th1) based on the current evaporation pressure value; The compressor is configured to include capacity control means (10) for controlling the operating capacity of the compressor (1) based on the required signal value regarding evaporation capacity.

In addition, the second solution means, as shown in FIG. 2, includes a variable capacity compressor (1), a cycle switching mechanism (2), a heat source side heat exchanger (3), and a ), the outdoor unit (X) has a first pressure reduction mechanism (4) for use, and a second pressure reduction mechanism (6) for the use side heat exchanger (7) and the use side heat exchanger (7). Multiple sets of indoor units (A
) to (D) are connected in parallel.

For each indoor unit (A) to (D), required capacity detection means (
T h1) and the user-side heat exchanger (7),
Evaporation pressure detection means (T h2
), and the evaporation pressure detection means (T h2
) to (T h2), and based on the current evaporation pressure value, the required capacity detection means (T h1) to (T h1)
correction means (51) for correcting the required evaporation capacity detected by
and a capacity control means (10) for controlling the operating capacity of the compressor (1) based on the request signal value for the required evaporation capacity corrected by the correction means (51).

Furthermore, as shown in FIG. 1 or 2, a third solution means, in the first or second solution means, adjusts the required evaporation capacity to the current evaporation pressure and the previous time. The configuration is such that the correction is made using the request signal value outputted to the input signal.

(Function) With the above configuration, in the invention of claim (1), when the required capacity detection means (Th1) detects the required evaporation capacity in each room during cooling operation, the correction means (51) adjusts the required evaporation capacity. The required evaporation capacity value is corrected based on the current evaporation capacity value detected by the evaporation pressure detection means (Th2). Then, the capacity control means (10) controls the operating capacity of the compressor (1) based on the corrected request signal value.

In that case, the required evaporation capacity detected by the required capacity detection means (T h1) is corrected by the current evaporation pressure in the utilization side heat exchanger (7), so that the pressure loss in the suction pipe of the compressor (1) and Capacity control is performed in accordance with the actual evaporation pressure, regardless of the actual evaporation pressure, and thus the lack of capacity caused by a decrease in the detected value due to pressure loss is resolved.

In addition, in the invention of claim (a), in particular, even in a multi-type air conditioner in which the length of piping from the indoor side to the outdoor side is long, the difference in the piping length of each indoor unit (A) to (D), etc. The lack of ability caused by this will be resolved.

Furthermore, in the invention of claim (3), the required evaporating pressure value is corrected by the current evaporating pressure value and the previously outputted required signal value and calculated as the required signal value. Through the comparison, the discrepancy between the demand signal caused by the length of the piping, etc. and the result of capacity control based on the demand signal is corrected, and the capacity of the compressor (1) is controlled based on a more accurate demand signal. You will be killed.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 3 onwards.

FIG. 3 shows the overall configuration of an embodiment according to the invention of claims (1) to (3), in which four indoor units (A) to (D) are arranged in parallel to - outdoor units (X). It is located in The outdoor unit (X) is equipped with a variable capacity compressor (1
) and an outdoor heat exchanger (3
), a four-way switching valve (2) as a cycle switching mechanism that switches as shown by the solid line in the figure during cooling operation, and as a broken line in the figure during heating operation, and a four-way switching valve (2) that adjusts the refrigerant flow rate during cooling operation and switches the refrigerant flow during heating operation. First electric expansion valve to reduce pressure (4)
and are arranged.

In addition, each of the above-mentioned indoor units (A) to (D) has the same configuration, and an indoor heat exchanger (
7) and a second electric expansion valve (6) as a pressure reducing mechanism that reduces the pressure of the refrigerant to the indoor heat exchanger (7).

The devices (1) to (7) in each of the units (X), (A) to (D) are sequentially connected to each other through refrigerant piping (11) so that the refrigerant can flow through the outdoor heat exchanger. A refrigerant circuit (1) in which heat is given by heat exchange with outdoor air in a heat exchanger (3) and released indoors in indoor heat exchangers (7) to (7).
2) is configured.

Next, (9) to (9) are each indoor unit (A) to (D)
The indoor control device (10) for controlling individual operations is an outdoor control device for controlling the operation of the outdoor unit (X), and the indoor control device (10) is an outdoor control device for controlling the operation of the outdoor unit (X). 10) are connected to each other through communication wiring so that signals can be sent and received.

On the other hand, sensors are installed in the device, and in each indoor unit (A) to (D), (Th1) is attached to the air suction port of the indoor heat exchanger (7), and the required evaporation pressure is A room temperature sensor (T h2) as a required capacity detection means for detecting the suction air temperature Ta corresponding to the value is attached to the liquid pipe side of the indoor heat exchanger (7). A liquid pipe sensor for detecting temperature (hereinafter referred to as evaporation pressure) Te, and each sensor (Th1) and (Th2) is connected to the indoor control device (
9) is connected to allow signal input. Further, in the outdoor unit (X), (Pe) is a pressure sensor arranged in the suction pipe of the compressor (1) to detect low pressure, and the pressure sensor (P e) is 1
0) so that signals can be input, and the outdoor control device (10) detects the pressure sensor ( Depending on the low pressure value detected in the compressor (1
) is designed to control the operating capacity of the Therefore,
The outdoor control device (10) has a function as a capacity control means.

During cooling operation of the device, the four-way switching valve (2) switches as shown by the solid line in the figure, and with the first electric expansion valve (4) open, each of the second electric expansion valves (6) to (6) The operation is performed while adjusting the opening degree appropriately, and after the discharged refrigerant is condensed in the outdoor heat exchanger (3), the indoor heat exchangers (7) to (7) of each indoor unit (A) to (D) are condensed. ) to evaporate. In addition,
When each indoor unit (A) to (D) performs heating operation at the same time, operation is performed using the flow of refrigerant opposite to that described above. In addition, although the explanation is omitted, each of the above indoor units (A
Even if any one of ) to (D) is stopped, the operating state is similar to that described above.

When the above device is in operation, each indoor unit (A) controls each of the above sensors (Th1) by the indoor control device (9).
, the intake air temperature Ta detected by (Th2)
The opening degree of the second electric expansion valve (6) is appropriately adjusted based on the evaporation pressure Te, while the request signal value Tea to be output to the outdoor control device (10) is calculated in the following procedure.

The flowchart in FIG. 4 shows the control contents of the indoor control device (9), and in step S1, the room temperature sensor
Intake air temperature Ta detected in 1) and indoor set temperature T
s, and in step S2, the temperature difference ΔTs between the two is calculated using the formula ΔTs-Ta-Ts, and then in step S
3, the required evaporation capacity Ter of the indoor heat exchanger (7) is determined based on this temperature difference ΔTs. Next, in step S4, the current evaporation temperature Te detected by the liquid pipe sensor (T h2) is input, and in step S5, the deviation ET between the two is calculated using the formula E.
After calculating TmTe-Ter, in step S6, the deviation ET obtained above is divided by the integral constant S to obtain the temperature correction amount ΔT.
Calculate e.

Then, in steps S7 to SO, the temperature correction amount ΔTe obtained above is compared with the minimum value ST of the temperature correction amount (ST is a constant having a positive value), and the temperature correction amount ΔT is set as ΔTe<- If 9T, ΔTe--5T, ΔTe>
If ST, ΔTe-0,2, -ST≦ΔTe≦ST
If so, the value ΔTe is determined as is.

Also, in step SI2, the previously output request signal value Te
ol is input, and in step SI3, the request signal value Tea is calculated by the formula T ea - Teol - ΔTe, and then
In steps S+4 to S+7, this request signal value Tea is compared with its minimum value Teomin and maximum value Teomax, and the request signal value Tea to be finally output to the outdoor control device (10) is determined as Teo > Teomax. If so, the maximum value T eoIIaX, T eo < T e
omln, the minimum value Teomin, Teomin
If ≦Teo≦T eOmax, the value Tea remains as it is
, the request signal value Tea is determined in step Sag, and the value Tea is set to the outdoor control device (1) in step SI9.
0).

In the above flow, in steps 85 to 818, the output of the liquid pipe sensor (evaporation pressure detection means) (Th2) is received, and the demand detected by the room temperature sensor (required capacity detection means) (Th1) based on the current evaporation pressure value is A correction means (51) for correcting the evaporation capacity is configured.

In addition, in the outdoor control device (10), each indoor control device (9
) to (9), the request signal value Tea of the indoor unit that causes the maximum pressure loss is
The operating capacity of the compressor (1) is controlled based on this.

Therefore, in the invention of claim (1), when the room temperature sensor (required capacity detection means) (Th1) detects the required evaporation capacity T'er in each room, the correction means (51) detects the required evaporation capacity value. Ter is the current evaporation capacity value T detected by the liquid pipe sensor (evaporation pressure detection means) (Th2)
Corrected based on e. Then, the outdoor control device (capacity control means) (10) controls the operating capacity of the compressor (1) based on the request signal value Tea, which is the corrected value.

In that case, the required evaporation capacity Ter detected by the room temperature sensor (T h1) is corrected by the current evaporation pressure Te, so the actual evaporation Capacity control is performed in accordance with the pressure, and it is therefore possible to eliminate the lack of capacity caused by a decrease in detected values due to pressure loss.

Further, as in the above embodiment, a plurality of indoor units (A)
In the invention of claim (2), which is characterized by a multi-type air conditioner having the above (D), even in a multi-type air conditioner in which the length of piping from the indoor side to the outdoor side is long, each indoor Insufficient capacity caused by differences in piping length between the units (A) to (D) can be resolved.

In that case, in the above embodiment, each indoor control device (9
) to (9), the required evaporation capacity value Ter is corrected by the correction means (51), but the correction processing may be performed within the outdoor control device (10), and the same effect as above is achieved. be able to.

Furthermore, in the invention of claim (3), the required evaporation pressure value Te
r is the current evaporation pressure value Te and the previously output request signal value T
Since the request signal value Tea is calculated by correcting the request signal value Teol, by comparing it with the previous request signal value Teol, the request signal caused by the length of the piping etc. and the capacity control based on the request signal are calculated. The deviation from the result is corrected to eliminate the difference, and the capacity of the compressor (1) can be controlled based on a more accurate request signal.

(Effect of the invention) As explained above, according to the invention of claim (1), the required evaporation capacity is corrected by the current evaporation capacity in the user side heat exchanger, and the corrected value is set as the required capacity. Since the operating capacity of the compressor is controlled, control is performed based on the actual evaporation pressure regardless of pressure loss in the piping, eliminating the lack of capacity of the heat exchanger on the user side caused by pressure loss, etc. Can be done.

Further, in the invention of claim (2), in the air conditioner including a plurality of indoor units, the request signal value to be outputted from each indoor unit to the outdoor side is determined according to the above claim (1).
Since the same correction processing as in the invention is performed, it is possible to solve the problem of insufficient capacity of the user-side heat exchanger caused by differences in piping length between the indoor units.

Furthermore, in the invention of claim (3), in the inventions of claims (1) and (1), the required evaporation capacity is further corrected using the previous required signal value, so that more accurate capacity control is achieved. be able to.

[Brief explanation of the drawing]

1 and 2 are claims (1) and ('), respectively.
FIG. 2 is a block diagram showing the configuration of the invention of No. 2I. FIG. 3 and subsequent figures show an embodiment of the present invention, FIG. 3 is a refrigerant system diagram showing its overall configuration, and FIG. 4 is a flowchart showing the details of control. (1) Compressor, (2) First four-way switching valve (cycle switching mechanism), (3) Outdoor heat exchanger (heat source side heat exchanger), (6)...・Second electric expansion valve (pressure reducing mechanism)
, (7)... Indoor heat exchanger (user side heat exchanger), (1
0)...Outdoor control device (capacity control means), (51)
... Correction means, (T h1) ... Room temperature sensor (required capacity detection means), (T h2) ... Liquid pipe sensor (evaporation capacity detection means).

Claims (3)

[Claims] (1) Variable capacity compressor (1), heat source side heat exchanger (3)
), a required capacity detection means for detecting a required indoor evaporation capacity during cooling operation in an air conditioner equipped with a refrigerant circuit (12) connected to a pressure reduction mechanism (6) and a user-side heat exchanger (7). (Th1), an evaporation pressure detection means (Th2) arranged in the user-side heat exchanger (7) to detect the evaporation pressure of the refrigerant, and an evaporation pressure detection means (Th2) that receives the output of the evaporation pressure detection means (Th2), A correction means (51) for correcting the required evaporation capacity detected by the required capacity detection means (Th1) based on the pressure value, and a compression unit based on the request signal value for the required evaporation capacity corrected by the correction means (51). 1. An operation control device for an air conditioner, comprising: capacity control means (10) for controlling the operating capacity of the air conditioner (1). (2) Variable capacity compressor (1), cycle switching mechanism (
2), the heat source side heat exchanger (3) and the heat source side heat exchanger (
3) an outdoor unit (X) having a first pressure reducing mechanism (4) for
), a plurality of indoor units (A) to (D) having a user-side heat exchanger (7) and a second pressure reduction mechanism (6) for the user-side heat exchanger (7) are connected in parallel. In the air conditioner made of
During cooling operation, required capacity detection means (Th1) detects the required indoor evaporation capacity, and evaporation pressure detection means (T
h2), and the evaporation pressure detection means (Th
2) a correction means (51) that receives the outputs of (Th2) and corrects the required evaporation capacity detected by the required capacity detection means (Th1) (Th1) based on the current evaporation pressure value;
An air conditioner comprising: capacity control means (10) for controlling the operating capacity of the compressor (1) based on the request signal value for the required evaporation capacity corrected by the correction means (51). Operation control device. (3) Claim (1) or (2) characterized in that the correction means (51) is configured to correct the required evaporation capacity using the current evaporation pressure and the previously output request signal value. ) The operation control device for the air conditioner described in ).