JP2002147819A - Refrigeration unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration unit, capable of reliably reducing a consumption power by a demand for power peak cut. SOLUTION: A controller (90) of an air-conditioner (10), being a refrigerating device, is provided with a consumption power detecting part (91). The consumption power detecting part (81) stores a characteristic function representing the consumption power of an electric motor for a compressor, by a condensing temperature and an evaporation temperature of a refrigerant in a refrigerating cycle. The consumption power detecting part (91) substitutes the condensing temperature and the evaporation temperature of a refrigerant, during operation for a characteristic function to calculate a consumption power of the electric motor. The controller (90) controls the capacity of a compressor unit (40) to within a range, where the detecting current value of the consumption power detecting part (91) does not exceed a prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration system for performing a refrigeration cycle.

[0002]

2. Description of the Related Art Conventionally, a refrigerating apparatus for circulating a refrigerant in a refrigerant circuit to perform a refrigerating cycle is known, and is widely used as an air conditioner or the like. The refrigerant circuit of the refrigeration apparatus is provided with a compressor for compressing the refrigerant. This compressor is generally driven by an electric motor. In many cases, the capacity of the compressor is made variable by changing the number of revolutions of the electric motor. In the refrigeration apparatus, when the compressor is driven by the electric motor, the refrigerant circulates in the refrigerant circuit while changing phase, thereby performing a refrigeration cycle.

[0003] Here, in the case of commercial and industrial facilities such as office buildings, there are circumstances in which the electricity rate is set based on the peak value (maximum value) of the power consumption. For this reason, control for reducing the power consumption of the refrigeration apparatus to a predetermined value or less is required, and conventionally, this has been dealt with by limiting the capacity of the compressor. That is, for example, when it is necessary to reduce the power consumption by 50%, the upper limit of the capacity of the compressor, specifically, the rotation speed (the number of rotations per second) of the motor driving the compressor is forcibly set to the maximum. The rotation speed was limited to 50%, and the power consumption of the electric motor was reduced.

[0004]

However, in the above-described control for limiting the capacity of the compressor, there is no guarantee that the power consumption of the motor of the compressor is surely equal to or less than a predetermined value. There was a problem that it was not able to respond sufficiently to. That is, the power consumption of the electric motor that drives the compressor is determined not only by the rotation speed but also by operating conditions such as the evaporation temperature and the condensation temperature of the refrigerant in the refrigeration cycle. Therefore, even if the rotation speed of the motor is simply reduced to half, the power consumption of the motor is not necessarily reduced to half. For this reason, the amount of reduction in the power consumption of the electric motor has become unclear, causing the above-described problem.

[0005] Further, in the conventional control, since the amount of reduction in power consumption of the motor is unknown, the capacity of the compressor is often limited too small so that the power consumption does not exceed the upper limit. That is, there is a possibility that the operation may be performed with the power consumption reduced more than necessary, and it is difficult to appropriately cut the power peak in this regard.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a refrigeration apparatus which can reliably reduce power consumption due to a request for a power peak cut. .

[0007]

According to a first aspect of the present invention, there is provided a variable capacity compressor means (40) having one or more compressors (41, 42) driven by an electric motor. The present invention is directed to a refrigerating apparatus that performs a refrigerating cycle by circulating a refrigerant in a refrigerant circuit (15) to which a compressor (41, 42) of the compressor means (40) is connected. The refrigerant state detecting means (74, 76) for detecting the evaporation temperature and the condensation temperature of the refrigerant in the refrigeration cycle, and at least the refrigerant state detecting means (7
4,76) and the characteristics of the compressor (41,42)
A power consumption detecting means (91) for calculating a value of electric power consumed by the motor in the compressor means (40); and a power consumption detecting means (91) for detecting a power consumption value of the power consumption detecting means (91) to be not more than a predetermined set value. Control means for controlling the capacity of the compressor means (40) (92, 9
3) is provided.

[0008] A second solution taken by the present invention is the first solution, wherein the control means (92, 93) is adapted to operate when the detected power value of the power consumption detection means (91) is less than a set value. Is the load-responsive operation of controlling the capacity of the compressor means (40) according to the load on the user side, and the detected power of the power consumption detection means (91) when the capacity of the compressor means (40) is adjusted by the load-responsive operation. When the value exceeds the set value, the power consumption regulating operation of controlling the capacity of the compressor means (40) is performed so that the detected power value becomes the set value.

According to a third aspect of the present invention, in the first or second aspect, the main body (11) provided with at least the compressor means (40) and the refrigerant state detecting means (74, 76). ), An operation management unit (95) provided with at least a power consumption detection means (91) and formed separately from the main body (11), the main body (11) and the operation management unit (9).
Communication means (96) for exchanging signals between 5).

The fourth solution taken by the present invention is the first or second solution, wherein the power consumption detection means (9
1) describes, as a characteristic of the compressor (41, 42), the relationship between the state of the suction refrigerant and the discharge refrigerant in the compressor (41, 42) and the power consumed by the electric motor of the compressor (41, 42). It is configured to be used.

A fifth solution taken by the present invention is the first or second solution, wherein the power consumption detection means (9
1) Substituting the values of the evaporation temperature and the condensation temperature of the refrigerant detected by the refrigerant state detecting means (74, 76) into a predetermined characteristic function based on the characteristics of the compressor (41, 42). Thus, the value of the power consumed by the electric motor of the compressor (41, 42) is calculated.

According to a sixth aspect of the present invention, in the fifth aspect, the power consumption detecting means (91) is configured so that the coefficient of the characteristic function can be changed by an external signal.

According to a seventh aspect of the present invention, in the above first or second aspect, the control means (92, 93)
Is configured such that the set value can be changed by an external signal.

-Operation- In the first solution, the compressors (41, 42) of the compressor means (40) are connected to the refrigerant circuit (15) of the refrigeration system. The compressors (41, 42) are driven by the electric motor to compress the refrigerant. As the compressors (41, 42), a completely closed type in which a compression mechanism and an electric motor are housed in one housing, or a structure in which a compression mechanism and an electric motor are formed separately and connected to each other by a drive shaft. Are exemplified. Compressor means (40)
Is constituted by one or a plurality of compressors (41, 42). The compressor means (40) is configured such that its capacity can be changed, for example, by changing the rotation speed of an electric motor that drives the compressors (41, 42). The compressor means (4
0) is composed of multiple compressors (41, 42),
The capacity of the compressor means (40) may be changed by changing the number of operating compressors (41, 42).

When the compressors (41, 42) are energized by energizing the electric motor, the refrigerant circulates in the refrigerant circuit (15) while changing phases, thereby performing a refrigeration cycle. That is, in the refrigerant circuit (15), the refrigerant circulates while repeatedly compressing, condensing, expanding, and evaporating. Then, a cooling operation in which the refrigerant absorbs heat from the object and evaporates, and a heating operation in which the refrigerant radiates heat to the object and condenses, are performed.

The refrigeration apparatus according to the present invention is provided with refrigerant state detecting means (74, 76), power consumption detecting means (91), and control means (92, 93). The refrigerant state detecting means (74, 76) is for detecting the evaporation temperature and the condensation temperature of the refrigerant circulating in the refrigerant circuit (15) during the refrigeration cycle. The power consumption detecting means (91) is a compressor (41, 42)
The power consumed by the electric motor in the compressor means (40) is calculated using at least the characteristic of the compressor means (74, 76) and the value detected by the refrigerant state detection means (74, 76). For example, when the compressor means (40) is composed of a plurality of compressors (41, 42) and there are a plurality of motors, the power consumption detecting means (91) determines the total value of the power consumption of each motor as the detected power. Value. On the other hand, the control means (92, 93) controls the compressor means so that the value of the power detected by the power consumption detecting means (91), that is, the detected power value of the power consumption detecting means (91) does not exceed the set value. Adjust the volume of (40) appropriately. Therefore, the power consumption of the motor is maintained at or below the predetermined set value.

In the second solving means, the control means (92, 9
3) performs the operation corresponding to the load. In the load handling operation, the control means (92, 93) changes the capacity of the compressor means (40) according to the load fluctuation on the user side. For example, when cooling an object, when the cooling load increases, the capacity of the compressor means (40) increases, and when the cooling load decreases, the compressor means (40) increases.
Reduce the capacity of This load handling operation is performed when the power consumption of the electric motor detected by the power consumption detection means (91) is less than a predetermined set value.

The control means (92, 93) according to the present invention comprises:
While performing the load response operation, the power consumption regulating operation is also performed.
In this power consumption regulating operation, assuming that the capacity of the compressor means (40) corresponds to the load on the user side by the load handling operation, the power consumption of the motor detected by the power consumption detecting means (91) is set to a predetermined value. It is performed when the value is exceeded. In such a case, the control means (92, 93) adjusts the capacity of the compressor means (40) such that the detected power value of the power consumption detecting means (91) is maintained at the set value as the power consumption regulating operation. Perform the operation of By this power consumption regulating operation, the compressor means (40) is operated at the maximum capacity within a range where the power consumption of the electric motor does not exceed the set value.

In the third solution, the main body (11),
An operation management unit (95) and communication means (96) are provided.
The main body (11) is provided with at least compressor means (40) and refrigerant state detecting means (74, 76). Operation Management Department (9
5) is provided with at least a power consumption detecting means (91). It should be noted that the control means (92, 93) includes a main body (1
It may be provided in 1) or may be provided in the operation management unit (95). The main body section (11) and the operation management section (95) are formed separately and installed at separate locations. Signals are exchanged between the main unit (11) and the operation management unit (95) via communication means (96). That is, the main unit (11) and the operation management unit (95) can communicate with each other by the communication means (96).

In the fourth solving means, the characteristics of the compressor (41, 42) in the power consumption detecting means (91) include the states of the suction refrigerant and the discharge refrigerant in the compressor (41, 42) and the characteristics of the compressor (41, 42). 41, 42) is used. The power consumption detecting means (91) calculates the power consumption of the electric motor in the compressor (41, 42) based on this relationship and the detection value of the refrigerant state detecting means (74, 76).

In the fifth solution, the compressor (41, 4
The power consumption detecting means (91) calculates the power consumption of the electric motor using a characteristic function determined based on the characteristic of 2).
That is, the power consumption detecting means (91) performs an operation by substituting the values of the evaporation temperature and the condensing temperature of the refrigerant detected by the refrigerant state detecting means (74, 76) into the characteristic function, and calculates the calculated value from the obtained operation value. Calculate the power consumption of the motor. Note that the characteristic function may be determined so that the calculated value itself becomes the power consumption,
Power consumption may be obtained by further operating the calculated value.

In the sixth solving means, the coefficient of the characteristic function in the power consumption detecting means (91) can be changed by an external signal. This external signal may be input from an input device or the like provided in the refrigerating device,
The information may be input from a remote place through a telephone line, the Internet, or the like.

In the seventh solving means, the control means (92, 9
The set value in 3) can be changed by an external signal. This external signal may be input from an input device or the like provided in the refrigeration apparatus, or may be input from a remote location through a telephone line, the Internet, or the like.

[0024]

According to the present invention, the power consumption detecting means (91) is provided in the refrigeration system to detect the power consumption of the electric motor. For this reason, after grasping the value of the electric power actually consumed by the electric motor during the operation of the refrigeration system, the control means (92, 93) should perform an operation for reducing the electric power consumption of the electric motor to a set value or less. Can be. Therefore, when there is a request for the power peak cut, the power consumption of the electric motor can be reliably suppressed to the set value or less, and the power consumption of the refrigeration system can be reduced to appropriately meet the request for the power peak cut. Become.

Further, in the present invention, the refrigerant state detecting means (7
The power consumption detection means (91)
Calculates the power consumption of the motor. Here, in order to control the operation of the refrigeration apparatus, the values of the evaporation temperature and the condensation temperature of the refrigerant during the refrigeration cycle are required. That is, usually, also in the conventional refrigerating apparatus, the refrigerant state detecting means (74, 76) for detecting the evaporating temperature and the condensing temperature of the refrigerant is provided.

Therefore, according to the present invention, the power consumption of the electric motor can be detected by using the detected value of the refrigerant state detecting means (74, 76) also provided in the conventional refrigeration system.
Therefore, the power consumption of the electric motor can be detected and the request for the power peak cut can be appropriately responded without increasing the number of parts of the refrigeration apparatus and the production cost.

In the second solving means, the control means (92, 93) is configured to perform a power consumption regulating operation. For this reason, the compressor means (40) can be operated with the maximum capacity possible under the constraint that the electric power consumption of the electric motor is equal to or less than the set value, and the maximum refrigeration capacity within the possible range while keeping the electric power consumption equal to or less than the set value. Can be demonstrated. Therefore,
It is possible to minimize the shortage of the cooling capacity accompanying the demand for the power peak cut.

In particular, in the sixth solving means, the coefficient of the characteristic function in the power consumption detecting means (91) can be changed by an external signal. For this reason, even after the installation of the refrigeration apparatus, it is possible to input a coefficient of an appropriate characteristic function according to the operating condition to the power consumption detection means (91), and to make the calculated value of the power consumption of the motor more accurate. can do.

Further, in the seventh solving means, the set value in the control means (92, 93) can be changed by an external signal. Therefore, even when the setting value needs to be changed after the installation of the refrigeration apparatus, such a request from the user can be accurately met.

[0030]

Embodiments of the present invention will be described below in detail with reference to the drawings. This embodiment is an air conditioner (10) that constitutes a refrigeration apparatus according to the present invention. The air conditioner (10) switches between a cooling operation and a heating operation.

As shown in FIG. 1, the air conditioner (10)
It has one outdoor unit (11) and two indoor units (12, 13), and is configured as a so-called multi-type. The air conditioner (10) includes a refrigerant circuit (15) and a controller (90). In the present embodiment, the number of the indoor units (12, 13) is two, but this is an example, and the number of the indoor units (12, 13) is appropriately determined according to the capacity and use of the outdoor unit (11). Just do it.

<< Configuration of Refrigerant Circuit >> The Refrigerant Circuit (15)
Is one outdoor circuit (20) and two indoor circuits (60,6
5), a liquid-side communication pipe (16), and a gas-side communication pipe (17). Two indoor circuits (60, 65) are connected in parallel to the outdoor circuit (20) via a liquid-side communication pipe (16) and a gas-side communication pipe (17).

The outdoor circuit (20) is housed in an outdoor unit (11). The outdoor circuit (20) includes a compressor unit (40), a four-way switching valve (21), an outdoor heat exchanger (22), an outdoor expansion valve (24), a receiver (23), and a liquid-side shutoff valve (25). ),
And a gas-side shut-off valve (26).

The compressor unit (40) comprises a first compressor (41) and a second compressor (42) connected in parallel, and constitutes compressor means. First and second compressors (4
1,42) are hermetic scroll compressors. That is, these compressors (41, 42) are configured by housing a compression mechanism and an electric motor that drives the compression mechanism in a cylindrical housing. The illustration of the compression mechanism and the electric motor is omitted. The first compressor (41) has a constant capacity in which the electric motor is always driven at a constant rotation speed. The second compressor (4
2) is a variable capacity type in which the number of revolutions of the motor is changed stepwise or continuously. The compressor unit (40) starts and stops the first compressor (41) and the second compressor (4).
By changing the capacity in 2), the capacity of the entire unit is variable.

The compressor unit (40) is provided with a suction pipe (4
3) and a discharge pipe (44). The suction pipe (43)
The inlet end thereof is connected to the first port of the four-way switching valve (21), and the outlet end thereof is branched into two, and each of the compressors (41, 42)
Is connected to the suction side. The discharge pipe (44) has an inlet end branched into two and connected to the discharge side of each compressor (41, 42), and an outlet end connected to the second port of the four-way switching valve (21). Have been. Further, a discharge-side check valve (45) is provided in a branch pipe of the discharge pipe (44) connected to the first compressor (41). The discharge-side check valve (45) allows only the refrigerant to flow in the direction flowing out of the first compressor (41).

The compressor unit (40) includes an oil separator (51), an oil return pipe (52), and an oil equalizing pipe (54). The oil separator (51) is provided in the middle of the discharge pipe (44). This oil separator (51) is a compressor (41,42)
To separate the refrigerating machine oil from the discharged refrigerant.
The oil return pipe (52) has one end connected to the oil separator (51) and the other end connected to the suction pipe (43). The oil return pipe (52) is for returning the refrigerating machine oil separated by the oil separator (51) to the suction side of the compressors (41, 42), and is provided with an oil return solenoid valve (53). Have. Equalizing oil pipe (54)
Has one end connected to the first compressor (41) and the other end connected to the suction pipe (43) near the suction side of the second compressor (42). This oil equalizing pipe (54) is connected to each compressor (4
This is for averaging the amount of refrigerating machine oil stored in the housing of (1, 42), and includes an oil equalizing solenoid valve (55).

The four-way switching valve (21) has a third port connected to the gas-side shut-off valve (26) by piping, and a fourth port connected to the upper end of the outdoor heat exchanger (22) by piping. Have been. The four-way switching valve (21) has a state in which the first port and the third port are in communication and the second port and the fourth port are in communication (a state shown by a solid line in FIG. 1); And the fourth port communicates with each other, and the second and third ports communicate with each other (the state shown by the broken line in FIG. 1). The switching operation of the four-way switching valve (21) causes the refrigerant circuit (1
The refrigerant circulation direction in 5) is reversed.

The receiver (23) is a cylindrical container for storing a refrigerant. The receiver (23) is connected to the outdoor heat exchanger (22) and the liquid-side shutoff valve (25) via the inflow pipe (30) and the outflow pipe (33).

The inflow pipe (30) has its inlet end branched into two branch pipes (30a, 30b) and its outlet end has a receiver (2).
3) Connected to the upper end. The first branch pipe (30a) of the inflow pipe (30) is connected to the lower end of the outdoor heat exchanger (22). The first branch pipe (30a) is provided with a first inflow check valve (31). The first inflow check valve (31)
Only the flow of the refrigerant from the outdoor heat exchanger (22) to the receiver (23) is allowed. The second branch pipe (30) of the inflow pipe (30)
b) is connected to the liquid side shut-off valve (25). This second
The branch pipe (30b) is provided with a second inflow check valve (32). The second inflow check valve (32) allows only the flow of the refrigerant from the liquid-side stop valve (25) to the receiver (23).

The outflow pipe (33) has its inlet end connected to the lower end of the receiver (23), and its outlet end branched into two branch pipes (33a, 33b). Outflow pipe (33) first
The branch pipe (33a) is connected to a lower end of the outdoor heat exchanger (22). The first branch pipe (33a) is provided with the outdoor expansion valve (24). The second branch pipe (33b) of the outflow pipe (33) is connected to the liquid-side stop valve (25). The second branch pipe (33b) is provided with an outflow check valve (34). The outflow check valve (34) allows only the flow of the refrigerant from the receiver (23) to the liquid-side stop valve (25).

The outdoor heat exchanger (22) is constituted by a cross-fin type fin-and-tube heat exchanger. In this outdoor heat exchanger (22), the refrigerant circuit (1
5) The refrigerant circulating and the outdoor air exchange heat.

The outdoor circuit (20) is further provided with a degassing pipe (35) and a pressure equalizing pipe (37). One end of the degassing pipe (35) is connected to the upper end of the receiver (23), and the other end is connected to the suction pipe (43). Also,
The degassing pipe (35) is provided with a degassing solenoid valve (36). On the other hand, one end of the pressure equalizing pipe (37) is connected to the gas venting solenoid valve (36) in the gas vent pipe (35) and the receiver (2).
The other end is connected to the discharge pipe (44). In addition, the equalizing pipe (37) has a check valve (38) for equalizing that allows only the flow of the refrigerant from one end to the other end.
Is provided. This pressure equalizing pipe (37)
When the outside air temperature rises abnormally and the pressure of the receiver (23) becomes excessively high during the stop of the operation, the gas refrigerant is released to prevent the receiver (23) from bursting. Therefore, the refrigerant does not flow through the pressure equalizing pipe (37) during the operation of the air conditioner (10).

Each of the indoor circuits (60, 65) includes an indoor unit (12,
13) are provided one by one. Specifically, the first indoor circuit (60) is housed in the first indoor unit (12), and the second indoor circuit (65) is housed in the second indoor unit (13).

The first indoor circuit (60) has a first indoor heat exchanger (61) and a first indoor expansion valve (62) connected in series. The first indoor expansion valve (62) is connected to the lower end of the first indoor heat exchanger (61) by piping. The second indoor circuit (65) is obtained by connecting the second indoor heat exchanger (66) and the second indoor expansion valve (67) in series. The second indoor expansion valve (67) is connected to the lower end of the second indoor heat exchanger (66) by piping.

The first and second indoor heat exchangers (61, 66)
Both are constituted by cross-fin type fin-and-tube heat exchangers. Each indoor heat exchanger (61,6
In 6), the refrigerant circulating in the refrigerant circuit (15) and the indoor air exchange heat.

One end of the liquid side communication pipe (16) is connected to the liquid side closing valve (25). This liquid side connection pipe (16)
Is branched into two at the other end, one of which is connected to the end of the first indoor circuit (60) on the side of the first indoor expansion valve (62), and the other is connected to the second indoor circuit (65). Of the second indoor expansion valve (67). One end of the gas side communication pipe (17) is connected to a gas side shutoff valve (26). The other end of the gas-side communication pipe (17) is branched into two, one of which is connected to the end of the first indoor circuit (60) on the side of the first indoor heat exchanger (61), The other is connected to the end of the second indoor circuit (65) on the side of the second indoor heat exchanger (66).

The outdoor unit (11) includes an outdoor fan (70)
Is provided. The outdoor fan (70) is for sending outdoor air to the outdoor heat exchanger (22). on the other hand,
Each of the first and second indoor units (12, 13) is provided with an indoor fan (80). The indoor fan (80) is for sending indoor air to the indoor heat exchangers (61, 66).

The air conditioner (10) is provided with a temperature and pressure sensor. Specifically, the outdoor unit (11) is provided with an outside air temperature sensor (71) for detecting the temperature of outdoor air. The outdoor heat exchanger (22) is provided with an outdoor heat exchanger temperature sensor (72) for detecting the heat transfer tube temperature. A suction pipe temperature sensor (73) for detecting a suction refrigerant temperature of the compressors (41, 42) is provided on the suction pipe (43).
And a low-pressure sensor (74) for detecting the suction refrigerant pressure of the compressor (41, 42). Discharge pipe (4
4) The discharge pipe temperature sensor (75) for detecting the refrigerant temperature discharged from the compressor (41, 42) and the high pressure sensor (75) for detecting the refrigerant pressure discharged from the compressor (41, 42) 76)
A high pressure switch (77) is provided. Each indoor unit (12, 13) is provided with one internal air temperature sensor (81) for detecting the temperature of indoor air. Each indoor heat exchanger (61, 66) is provided with one indoor heat exchanger temperature sensor (82) for detecting the heat transfer tube temperature. The indoor heat exchanger (61,6) in each indoor circuit (60,65)
In the vicinity of the upper end of 6), one gas side temperature sensor (83) for detecting the temperature of the gas refrigerant flowing through the indoor circuit (60, 65) is provided.

<< Configuration of Controller >> The controller (90) includes a power consumption detecting section (91) and a load corresponding section (92).
And a power consumption regulating unit (93). The controller (90) controls the operation of the air conditioner (10) in response to a signal from the sensors and a command signal from a remote controller or the like. Specifically, the controller (90) adjusts the opening degree of the outdoor expansion valve (24) and the indoor expansion valves (62, 67),
Switching of the four-way switching valve (21), opening and closing of the gas release solenoid valve (36), oil return solenoid valve (53), and oil equalization solenoid valve (55), and capacity control of the compressor unit (40) Do. The power consumption detecting section (91) of the controller (90) constitutes a power consumption detecting means, and includes a load handling section (92) and a power consumption regulating section (93).
Constitutes control means.

The power consumption detecting section (91) is configured to calculate the power consumed by the motors of the first and second compressors (41, 42) by a method similar to the so-called compressor curve method. I have. In the power consumption detecting section (91), a characteristic function determined based on the characteristics of the compressor (41, 42) is recorded in advance. Further, the power consumption detecting section (91) includes a low pressure pressure sensor (74) constituting a refrigerant state detecting means.
And the detection value of the high pressure sensor (76).
Power detecting section (91), evaporation temperature of the refrigerant saturation temperature corresponding to the refrigerant at the detection value P _E of the low-pressure pressure sensor (74) T _E
And then, the corresponding saturation temperature of the refrigerant at the detection value P _C of the high-pressure sensor (76) and the condensation temperature T _C of the coolant. And
Power detecting section (91), a pressure sensor (74, 76) of the refrigerant obtained from the detection value the evaporation temperature T _E and the condensation temperature T _C compressors by substituting the characteristic function being recorded (41 ,Four
2) Calculate the electric power consumption of the motor,
The total value of the power consumption calculated for each motor described in 42) is output as a detected power value.

The characteristic function recorded in the power consumption detecting section (91) will be described with reference to FIG. Superheat degree SH of refrigerant at evaporator outlet and supercooling degree of refrigerant at condenser outlet
SC is fixed to an appropriate value. Knowing the evaporation temperature T _E of the refrigerant, since the degree of superheat SH is fixed, it can be specified temperature and pressure of the suction refrigerant of the compressor. Also, if the condensation temperature T _C of the refrigerant is known, the temperature and pressure of the refrigerant discharged from the compressor can be specified. Therefore, the refrigerant pressure at the suction side and the discharge side of the compressor can be specified, and the flow rate of the refrigerant discharged from the compressor and the electric power consumed by the motor of the compressor are obtained from the performance test performed on the compressor in advance. Can be That is, if a fixed degree of superheating SH and subcooling degree SC of the refrigerant, as shown in equation, the power consumption W _i of the motor of the compressor, condensation of the refrigerant in the refrigeration cycle temperature T _C and the evaporation temperature T _E
As a function of _{W i = f (T C,} T E) ... W i: the motor power T _C: refrigerant condensation temperature T _E: evaporation temperature of the refrigerant

As a specific example of the characteristic function shown by the above equation, the one shown by the equation can be mentioned. The characteristic function represented by this equation represents a result of a performance test performed in advance for a model adopted as the compressor (41, 42) as a second-order approximation equation. _{W i = R (1) +} R (2) T C + R (3) T E + R (4) T C 2 + R (5) T C T E + R (6) T E 2 ... R (i), i = 1 To 6: coefficient

The power consumption detecting section (91) of the controller (90) according to the present embodiment stores in advance the characteristic function represented by the above equation and the coefficient R (i). The coefficient R (i) is related to the first compressor (41) and the second compressor (4
2) are separately stored.

Here, for the second compressor (42) having a variable capacity, the value of the coefficient R (i) depends on the rotation speed (the number of rotations per second) of the motor of the second compressor (42). Are different. For this reason, the power consumption detection unit (91) performs the following Table 1
As shown in FIG. 7, six coefficients R (i) are stored for each of the three rotation speeds 30, 60, and 90 [1 / s]. Specifically, r ₁₁ ,..., R are used as the coefficient R (i) when the rotation speed is 30 [1 / s].
₆₁ is _defined as a coefficient R (i) for a rotation speed of 60 [1 / s], r ₁₂ ,
..., and r _62, r _13, ..., and stores the r ₆₃ respectively as a coefficient in the case of the rotational speed 90 [1 / s] R ( i).

[Table 1]

When calculating the power consumption of the motor of the second compressor (42), the power consumption detection section (91) complements the coefficient R (i) corresponding to the rotation speed of the motor at that time, Power consumption is calculated using the obtained value of the coefficient R (i). Incidentally, not only the condensation temperature T _C and the evaporation temperature T _E of the refrigerant, the characteristic function containing as variables the rotational speed of the motor, may represent a power consumption W _i.

Incidentally, the coefficient R (i) of the characteristic function may be stored in the power consumption detecting section (91) from the time of shipment of the air conditioner (10), or the air conditioner (10) was trial-operated. You may make it input to a power consumption detection part (91) later. Also, after the air conditioner (10) is installed, the value of the coefficient R (i) stored in the power consumption detector (91) is changed by inputting an external signal from a remote service center through a telephone line or the like. You may make it.

The load handling unit (92) is adapted to operate the compressor unit (4) according to the load on the user side, that is, the cooling load or the heating load in the room.
It is configured to perform a load response operation for controlling the capacity of 0). Specifically, the load corresponding unit (92) starts and stops the first compressor (41) based on the difference between the set room temperature input by a remote controller or the like and the temperature detected by the inside air temperature sensor (81). The capacity of the second compressor (42) is changed to adjust the capacity of the compressor unit (40).

The power consumption regulating section (93) performs the power consumption regulating operation by interrupting the load handling operation of the load handling section (92). This power consumption regulation operation is performed only when the detected power value of the power consumption detection unit (91) exceeds the set value, given the capacity of the compressor unit (40) based on the load handling operation. And power consumption regulation part (93)
Performs an operation of adjusting the capacity of the compressor unit (40) such that the detected power value of the power consumption detecting unit (91) is maintained at a set value as a power consumption regulating operation.

The set value of the power consumption regulating section (93) is appropriately set when the air conditioner (10) is installed.
However, after the air conditioner (10) is installed, the set value of the power consumption regulating unit (93) may be changed by inputting an external signal from a remote service center through a telephone line or the like.

-Operating operation- During the operation of the air conditioner (10), the refrigerant circulates in the refrigerant circuit (15) while changing its phase, and a vapor compression refrigeration cycle is performed. The air conditioner (10) switches between a cooling operation and a heating operation.

<< Cooling operation >> During the cooling operation, a cooling operation in which the indoor heat exchangers (61, 66) become evaporators is performed. During the cooling operation, the four-way switching valve (21) is in a state shown by a solid line in FIG. The outdoor expansion valve (24) is fully closed, and the first and second indoor expansion valves (62, 67) are each adjusted to a predetermined opening. The gas venting solenoid valve (36) is kept closed, and the oil return solenoid valve (53) and the oil equalizing solenoid valve (55) are opened and closed as appropriate. The operation of these valves is performed by the controller (90). At this time, the controller (90) adjusts the opening degree of each indoor expansion valve (62, 67) so that the degree of superheat of the gas refrigerant flowing out of each indoor heat exchanger (61, 66) becomes constant.

The compressor (41, 42) of the compressor unit (40)
Is operated, the refrigerant compressed by these compressors (41, 42) is discharged to the discharge pipe (44). This refrigerant flows into the outdoor heat exchanger (22) through the four-way switching valve (21). In the outdoor heat exchanger (22), the refrigerant releases heat to outdoor air and condenses. The refrigerant condensed in the outdoor heat exchanger (22) passes through the inflow pipe (3
0) into the first branch pipe (30a) and the first inflow check valve (3
After passing through 1), it flows into the receiver (23). Thereafter, the refrigerant flows from the receiver (23) into the outflow pipe (33), passes through the outflow check valve (34), and flows into the liquid-side communication pipe (16).

The refrigerant flowing into the liquid side communication pipe (16) is divided into two parts, one of which flows into the first indoor circuit (60) and the other flows into the second indoor circuit (65). Each indoor circuit (60,6
In 5), the inflowing refrigerant is depressurized by the indoor expansion valves (62, 67) and then flows into the indoor heat exchanger (61, 66). In the indoor heat exchangers (61, 66), the refrigerant absorbs heat from indoor air and evaporates. That is, indoor air is cooled in the indoor heat exchangers (61, 66).

The refrigerant evaporated in each of the indoor heat exchangers (61, 66) flows into the gas side communication pipe (17), and after joining, flows into the outdoor circuit (20). Thereafter, the refrigerant is supplied to the four-way switching valve (2
1) and through the suction pipe (43) to the compressor unit (4
0) is sucked into the compressor (41, 42). These compressors (4
1,42) compresses the sucked refrigerant and discharges it again. In the refrigerant circuit (15), such circulation of the refrigerant is repeated.

<< Heating Operation >> During the heating operation, a heating operation is performed in which the indoor heat exchangers (61, 66) become condensers. During this heating operation, the four-way switching valve (21) is in the state shown by the broken line in FIG. Outdoor expansion valve (24), first and second
Each of the indoor expansion valves (62, 67) is adjusted to a predetermined opening degree. The oil return solenoid valve (53) and the oil equalizing solenoid valve (55) are opened and closed as appropriate. The degassing solenoid valve (36) is always kept open during the heating operation. The operation of these valves is performed by the controller (90).

The compressor (41, 42) of the compressor unit (40)
Is operated, the compressed refrigerant is discharged from the compressors (41, 42) to the discharge pipe (44). The refrigerant flowing through the discharge pipe (44) passes through the four-way switching valve (21), flows into the gas side communication pipe (17), and is distributed to each indoor circuit (60, 65).

The refrigerant flowing into the first indoor circuit (60) of the first indoor unit (12) releases heat to indoor air in the first indoor heat exchanger (61) and condenses. In the first indoor heat exchanger (61), the indoor air is heated by heat release of the refrigerant. The refrigerant condensed in the first indoor heat exchanger (61) flows into the liquid side communication pipe (16) after being decompressed by the first indoor expansion valve (62).

The refrigerant flowing into the second indoor circuit (65) of the second indoor unit (13) releases heat to indoor air in the second indoor heat exchanger (66) and condenses. In the second indoor heat exchanger (66), the indoor air is heated by heat release of the refrigerant. The refrigerant condensed in the second indoor heat exchanger (66) flows into the liquid side communication pipe (16) after being depressurized by the second indoor expansion valve (67).

The first indoor circuit (60) and the second indoor circuit (6
The refrigerant that has flowed into the liquid-side connecting pipe (16) from 5) merges and then flows into the outdoor circuit (20). The refrigerant flowing into the outdoor circuit (20) flows through the second branch pipe (30b) of the inflow pipe (30), passes through the second inflow check valve (32), and flows into the receiver (23). The refrigerant flowing into the receiver (23) is in a gas-liquid two-phase state. Among the refrigerants, the liquid refrigerant accumulates at a lower portion of the receiver (23), and the gas refrigerant accumulates at an upper portion of the receiver (23). That is, in the receiver (23), the inflow gas-liquid two-phase refrigerant is separated into the liquid refrigerant and the gas refrigerant.

The liquid refrigerant stored in the receiver (23) passes through the outflow pipe (33) and is reduced in pressure by the outdoor expansion valve (24). The decompressed refrigerant is sent to the outdoor heat exchanger (22), where it absorbs heat from outdoor air and evaporates. The evaporated refrigerant passes through the four-way switching valve (21) and flows into the suction pipe (43). On the other hand, the gas refrigerant stored in the receiver (23) is
Flows into The refrigerant flowing through the degassing pipe (35) is decompressed when passing through the degassing solenoid valve (36), and then flows into the suction pipe (43). In the suction pipe (43), the gas refrigerant from the outdoor heat exchanger (22) and the gas refrigerant from the vent pipe (35) merge. Then, the combined gas refrigerant is sucked into the compressors (41, 42) of the compressor unit (40). These compressors (41, 42) compress the drawn refrigerant and discharge it again. In the refrigerant circuit (15), such circulation of the refrigerant is repeated.

<< Operation of Controller >>
The power consumption detection unit (91) of (0) performs an operation of calculating a value of power consumed by the electric motor of the compressor (41, 42). Specifically, the power consumption detection unit (91) obtains the evaporation temperature and the condensation temperature of the refrigerant in the refrigeration cycle from the input detection values of the low-pressure pressure sensor (74) and the high-pressure pressure sensor (76). Then, the power consumption detection unit (91) substitutes the obtained values of the evaporation temperature and the condensation temperature of the refrigerant into the characteristic function represented by the above equation to calculate the power consumption of the electric motor in each compressor (41, 42). It calculates and outputs the sum of the values obtained for each motor as the detected power value.

Here, the coefficient in the characteristic function of the above equation
When the value of the superheat degree SH and the degree of supercooling SC of the refrigerant assumed when determining R (i) is different from the value of the superheat degree SH and the degree of supercooling SC of the refrigerant in the actual refrigeration cycle There is also.
In such a case, the power consumption detecting unit (91) substitutes the values obtained by substituting the evaporation temperature and the condensation temperature of the refrigerant into the above equation,
Correction is made using the actual superheat degree SH and supercool degree SC of the refrigerant.

The operation of the load handling unit (92) and the power consumption regulating unit (93) of the controller (90) will be described with reference to FIG. FIG. 3 shows a change over time in one day regarding the power consumption of the air conditioner (10) when performing the cooling operation in the summer, that is, the power consumption of the electric motor in the compressors (41, 42). .

When the power is turned on around 8:00, the compressor (4
(42) Electric power is supplied to the electric motors and the air conditioners (10)
Is started. The capacity of the compressor unit (40) is changed according to the change in the cooling load by the load handling operation of the load handling unit (92). When the capacity of the compressor unit (40) changes, the detected power value of the power consumption detection unit (91), that is, the value of the power consumed by the motor of the compressor (41, 42) in the compressor unit (40) also changes. I do. In the morning, the cooling load is not so large, and the detected power value of the power consumption detecting unit (91) is equal to or less than a predetermined set value A (kW). Therefore, the capacity of the compressor unit (40) by the load corresponding unit (92) is reduced. Control is continued.

Thereafter, the cooling load increases as the outside air temperature rises, and the detected power value of the power consumption detecting section (91) also increases. When the detected power value of the power consumption detecting section (91) reaches the set value A shortly after 12:00, the power consumption regulating section (93) replaces the load corresponding operation of the load corresponding section (92). The operation controls the capacity of the compressor unit (40). That is, the capacity of the compressor unit (40) is adjusted such that the detected power value of the power consumption detection unit (91) is maintained at the set value A.

Here, while the power consumption regulating unit (93) controls the capacity of the compressor unit (40), the cooling capacity of the air conditioner (10) is insufficient with respect to the cooling load. Will be impaired. However, since the power consumption regulation unit (93) adjusts the capacity of the compressor unit (40) so that the detected power value of the power consumption detection unit (91) becomes the set value A, the compressor unit (40) The capacity of ()) is maximum within a range where the power consumption of the motor does not exceed the set value A. That is, the air conditioner (10) exhibits the maximum cooling capacity obtained under the constraint that the power consumption of the motor is kept at or below the set value A. Therefore, a decrease in comfort due to the limitation of power consumption is minimized.

When the outside air temperature starts to fall after about 14:00, the cooling load in the room decreases accordingly. 16
When the time comes, even when the capacity of the compressor unit (40) is controlled by the load handling unit (92), the detected power value of the power consumption detecting unit (91) falls below the set value A.
Therefore, instead of the power consumption regulating operation of the power consumption regulating unit (93), the capacity control of the compressor unit (40) by the load handling operation of the load handling unit (92) is restarted. Thereafter, the cooling operation is continued while controlling the capacity of the compressor unit (40) by the load handling unit (92), and the power of the air conditioner (10) is turned off around 20:00.

-Effects of the Embodiment- In this embodiment, the detection value of the sensor is input to the power consumption detection section (91) of the controller (90), and the power consumption of the electric motor in the compressor (41, 42) is reduced by the power consumption. It is calculated by the detection unit (91). Therefore, after grasping the value of the electric power actually consumed by the electric motor of the compressor (41, 42) during the operation of the air conditioner (10), the operation for reducing the electric power consumption of the electric motor to the set value or less is performed. This can be performed by the controller (90). Therefore, when it is necessary to cut off the power peak, the capacity of the compressor unit (40) can be controlled while considering the detected power value of the power consumption detection unit (91), and the compressor (41, 4) can be controlled.
The power consumption of the electric motor in 2) can be reliably suppressed to the set value or less, and it is possible to accurately meet the demand for the power peak cut.

Further, in the present embodiment, by utilizing the detection values of the low pressure sensor (74) and the high pressure sensor (76), the compressor (41, 42) is used in the power consumption detection section (91).
Is calculated. Here, the low-pressure pressure sensor (74) and the high-pressure pressure sensor (76) are sensors provided for operation control even in a conventional air conditioner that does not calculate the power consumption of the electric motor. Therefore,
According to the present embodiment, the power consumption of the electric motor can be calculated in the power consumption detection unit (91) using the detection value of the sensor also provided in the conventional air conditioner. Therefore, the air conditioner (1
The power consumption of the electric motor can be detected and the request for the power peak cut can be appropriately responded without increasing the number of parts and the manufacturing cost in the case of 0).

In this embodiment, the controller (9
0) The compressor (41, 42)
The capacity control of the compressor unit (40) is performed so that the power consumption of the electric motor in (1) is maintained at the set value. Therefore, according to the present embodiment, it is possible to minimize a decrease in comfort caused by responding to the request for the power peak cut.

The effect will be described. As described above, in the related art, the capacity of the compressor unit (40) is uniformly limited to a capacity where the power consumption of the motor is expected to fall below the set value. It was trying to keep the power consumption below the set value. However, for example, a compressor unit (40)
Halving the capacity does not necessarily mean that the power consumption of the motor is halved. Therefore, according to this conventional method, as shown in FIG. 4, there is a possibility that the capacity of the compressor unit (40) is limited to an unnecessarily small value.
In many cases, the cooling capacity of the air conditioner (10) became too small, greatly reducing comfort.

On the other hand, according to the present embodiment, the maximum possible power can be supplied to the motors of the compressors (41, 42) by the power consumption regulating operation of the power consumption regulating section (93). . For this reason, the compressor unit (40) can be operated with the maximum capacity when the power consumption of the electric motor is limited to the set value A or less, and the maximum cooling capacity can be obtained as much as possible. Therefore, according to the present embodiment, it is possible to keep the power consumption of the electric motor at or below the set value A and respond to the request for the power peak cut, while minimizing the accompanying decrease in comfort.

-Modification of Embodiment- In the above embodiment, the controller (90) of the outdoor unit (11)
However, instead of this, an operation management unit (95) that is separate from the outdoor unit (11), which is a main body, is installed as shown in FIG. The power management unit (95) may be provided with a power consumption detection unit (91).

In this modification, the operation management section (95)
It is installed away from the building where the air conditioner (10) is installed. The operation management unit (95) and the air conditioner (10) installed at remote locations can communicate with each other via a telephone line (96) as a communication means.

In the outdoor unit (11), the low-pressure pressure sensor (7
4) and the value detected by the high pressure sensor (76) are transmitted to the operation management unit (95) through the telephone line (96). The power consumption detection unit (91) of the operation management unit (95) substitutes the input detection value for the characteristic function, and thereby the electric power consumed by the electric motor of the compressor (41, 42) in the compressor unit (40). Is calculated. The value of the power consumption calculated by the power consumption detection unit (91) is transmitted to the outdoor unit (1) through the telephone line (96).
It is transmitted to the controller (90) of 1). In the controller (90), the capacity of the compressor unit (40) is controlled by the load handling unit (92) and the power consumption regulating unit (93) based on the input power consumption value.

In this modification, the power consumption detecting section (91)
Although only the operation management unit (95) is provided in the operation management unit (95), both the power consumption detection unit (91) and the power consumption regulation unit (93) may be provided in the operation management unit (95). In this case, the operation management unit (95) calculates the power consumption in the power consumption detection unit (91) and determines the capacity of the compressor unit (40) in the power consumption regulation unit (93). Power Consumption Regulation Department (9
The capacity of the compressor unit (40) determined in 3) is transferred to the controller (90) of the outdoor unit (11) through the telephone line (96).
Sent to Then, the controller (90) controls the capacity of the compressor unit (40) based on the input signal.

Although the telephone line (96) is used as the communication means in this modification, the Internet or the like may be used instead of the telephone line (96).

[0088]

In [Other Embodiments of the Invention above embodiment, expressed as a characteristic function of the condensation temperature T _C and the evaporation temperature T _E of the refrigerant power consumption W _i of the motor in a refrigeration cycle of the compressor (41, 42) (Formula ), This characteristic function to the controller (9
0) is stored in the power consumption detection section (91). In contrast, represents the current flowing through the electric motor of the compressor (41, 42) as a characteristic function of the condensation temperature T _C and the evaporation temperature T _E of the refrigerant in the refrigeration cycle, the power consumption detecting unit of this characteristic function (91) It may be stored. In this case, the power consumption detecting unit (91) is substituted into the characteristic function of storing the resulting condensation temperature T _C and the evaporation temperature T _E to calculate the current flowing through the motor, from the obtained current value of the electric motor This will lead to power consumption.

In the above embodiment, the controller (90) is provided with the power consumption detecting section (91), and the compressor (41, 4)
The power consumed by the motor in 2) is calculated. On the other hand, an ammeter may be provided to detect a current value actually flowing through the motor of the compressor (41, 42), and power consumption of the motor may be detected by actually measuring a current value flowing through the motor.

[Brief description of the drawings]

FIG. 1 is a piping diagram of a refrigerant circuit in an air conditioner according to an embodiment.

FIG. 2 is a Mollier diagram for describing a characteristic function stored in a power consumption detection unit of the controller according to the embodiment.

FIG. 3 is a relational diagram between power consumption and time showing a change in power consumption during a cooling operation of the air conditioner according to the embodiment.

FIG. 4 is a relationship diagram between power consumption and time showing a change in power consumption during a cooling operation of the air conditioner according to the related art.

FIG. 5 is a schematic configuration diagram of an air conditioner according to a modified example of the embodiment.

[Explanation of symbols]

 (15) Refrigerant circuit (40) Compressor unit (compressor means) (41) First compressor (42) Second compressor (74) Low pressure pressure sensor (refrigerant state detecting means) (76) High pressure pressure sensor (refrigerant) (State detection means) (91) Power consumption detection section (Power consumption detection means) (92) Load handling section (Control means) (93) Power consumption regulation section (Control means) (95) Operation management section (96) Telephone line ( Communication means)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L060 AA03 AA08 CC04 CC10 CC16 CC19 DD02 DD03 DD05 EE02 3L061 BA05 BB03

Claims (7)

[Claims] 1. A variable displacement compressor means (40) having at least one compressor (41, 42) driven by an electric motor, wherein the compressor (41, 42) of the compressor means (40) is provided. A refrigeration apparatus for performing a refrigeration cycle by circulating a refrigerant in a connected refrigerant circuit (15), comprising: refrigerant state detection means (74, 76) for detecting an evaporation temperature and a condensation temperature of the refrigerant in the refrigeration cycle; Based on at least the detected value of the refrigerant state detecting means (74, 76) and the characteristics of the compressor (41, 42), the compressor means (4
0) a power consumption detecting means (91) for calculating a value of electric power consumed by the motor; and the compressor means (40) so that the detected power value of the power consumption detecting means (91) is equal to or less than a predetermined set value. And a control means (92, 93) for controlling the capacity of the refrigeration system. 2. The refrigeration apparatus according to claim 1, wherein the control means (92, 93) compresses the power in accordance with the load on the user side when the detected power value of the power consumption detecting means (91) is less than a set value. A load corresponding operation for controlling the capacity of the compressor means (40); and adjusting the capacity of the compressor means (40) by the load corresponding operation, when the detected power value of the power consumption detecting means (91) exceeds a set value. A refrigeration apparatus configured to perform a power consumption regulating operation of controlling the capacity of the compressor means (40) so that the detected power value becomes a set value. 3. The refrigerating apparatus according to claim 1, wherein at least the compressor means (40) and the refrigerant state detecting means (7).
A main body section (11) provided with at least a power consumption detecting means (91), and an operation management section (95) formed separately from the main body section (11); A refrigerating apparatus comprising: a communication unit (96) for transmitting and receiving signals between the unit (11) and the operation management unit (95). 4. The refrigeration apparatus according to claim 1, wherein the power consumption detecting means (91) determines the states of the suction refrigerant and the discharge refrigerant in the compressor (41, 42) and the state of the compressor (41, 42). The relationship between the power consumed by the motor and the compressor (41, 42)
A refrigeration device configured to be used as a characteristic of the refrigeration system. 5. The refrigeration apparatus according to claim 1, wherein the power consumption detecting means (91) is a refrigerant state detecting means for a predetermined characteristic function based on characteristics of the compressor (41, 42). A refrigeration apparatus configured to calculate the value of electric power consumed by the electric motor of the compressor (41, 42) by substituting the values of the evaporation temperature and the condensation temperature of the refrigerant detected by (74, 76). . 6. The refrigerating apparatus according to claim 5, wherein the power consumption detecting means (91) is configured to be able to change a coefficient of the characteristic function by an external signal. 7. The refrigerating apparatus according to claim 1, wherein the control means (92, 93) is configured to be able to change a set value by an external signal.