JP2016188728A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner that prevents failure of occurrence of a thermo-off state immediately after start of a cooling operation.SOLUTION: An air conditioner includes: a cooling operation control section for performing a cooling operation; a start-up control section for performing start-up control; and a target evaporation temperature determination section. In the cooling operation, the rotational frequency of a compressor is adjusted so that an evaporation temperature of a refrigerant comes close to a target evaporation temperature. In the start-up control, for a predetermined period immediately after start-up, the compressor is operated at predetermined rotational frequency. The target evaporation temperature determination section determines an initial TeS that is the target evaporation temperature when the start-up control is switched to the cooling operation control, on the basis of an outside air temperature Ta. The target evaporation temperature determination section determines the initial TeS in a range that does not exceed an upper limit target evaporation temperature W changeable according to setting.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an air conditioner.

  Conventionally, there exists an air conditioner including a refrigerant circuit configured by connecting an indoor unit to an outdoor unit. Several air conditioners that control the air conditioning capability of the outdoor unit (specifically, the operating capacity of the compressor) have been proposed so that the evaporation temperature of the refrigerant in the refrigerant circuit becomes the target evaporation temperature. For example, in an air conditioner disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-147823), a target value of an evaporation temperature is determined based on an air conditioning load characteristic or a set temperature of a building, and the evaporation temperature of the refrigerant is the target. The capacity of the compressor is controlled to be a value.

  According to the air conditioner as described above, by changing the target evaporation temperature, excessive air conditioning capacity of the outdoor unit is suppressed, and the repetition frequency of operation / stop of the indoor unit and the compressor is reduced, thereby saving energy. Can be improved.

  However, when such an air conditioner is installed in a building (equipment) that requires cooling operation in a state where the outside air temperature is low, it is sufficient to reduce the repetition frequency of the operation / stop of the indoor unit and the compressor. It may not be possible. Specifically, when the outside air temperature is low, the cooling capacity increases and the capacity becomes excessive, and the indoor unit thermo-off (when the indoor temperature in the indoor unit performing the air conditioning operation becomes the set temperature, the indoor unit The frequency of stopping air conditioning operation) tends to increase. If the target evaporation temperature does not reach an appropriate value particularly at the start of the cooling operation, the thermo-off occurs immediately after the startup control.

  The subject of this invention is providing the air conditioning apparatus by which the malfunction which thermo-offs immediately after a cooling operation start is suppressed.

  An air conditioner according to a first aspect of the present invention includes a cooling operation control unit that performs a cooling operation, an activation control unit that performs activation control, and a target evaporation temperature determination unit. In the cooling operation, the cooling operation control unit adjusts the rotation speed of the compressor so that the evaporation temperature of the refrigerant approaches the target evaporation temperature. In the startup control, the startup control unit drives the compressor at a predetermined rotational speed for a predetermined period immediately after startup. The target evaporating temperature determining unit determines a target evaporating temperature when the activation control is switched to the cooling operation control based on the outside air temperature. The target evaporation temperature determination unit determines the target evaporation temperature within a range that does not exceed the upper limit target evaporation temperature that can be changed by setting.

  In this air conditioner, immediately after startup, the compressor is first driven at a predetermined rotational speed. Thereafter, when the start-up control ends, the operation mode is switched to the cooling operation control. The target evaporation temperature at that time is determined based on the outside air temperature by the target evaporation temperature determination unit. For this reason, for example, even when an air conditioner is installed in a cold region and the cooling operation is performed in a state where the outside air temperature is low, the target evaporation at the initial stage of the cooling operation is considered in view of the tendency that the cooling capacity increases according to the outside air temperature. The temperature can be determined high.

  This makes it possible to realize a situation in which the target evaporation temperature at the start of the cooling operation becomes higher when the outside air temperature is lower than when the outside air temperature is high, and it is possible to suppress the problem of thermo-off immediately after the start of the cooling operation. It becomes possible.

  Further, in this air conditioner, the target evaporation temperature is determined in a range not exceeding the upper limit target evaporation temperature that can be changed by setting. If the upper limit target evaporation temperature is a fixed value, for example, 8 ° C., the target evaporation temperature is 8 ° C. even when the air conditioner is installed in an area where the outside air temperature is very low and the cooling capacity is excessive. It becomes the upper limit, and there is a high possibility that the thermo-off will occur soon after the start of the cooling operation.

  However, in this air conditioner, since the upper limit target evaporation temperature can be changed by setting, the upper limit target evaporation temperature can be changed according to the installation environment. Thereby, the malfunction which thermo-offs immediately after the cooling operation start can be suppressed more.

  An air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect, and further includes an energy saving request setting unit. The energy saving request setting unit sets the degree of request for reduction of energy consumption. The target evaporation temperature determining unit changes the upper limit target evaporation temperature according to the degree of energy consumption reduction request set by the energy saving request setting unit.

  Since this air conditioner includes an energy saving request setting unit, a user who considers saving of energy consumption can set the degree of saving, that is, the degree of request for reduction of energy consumption. In addition, the target evaporation temperature determination unit can change the upper limit target evaporation temperature according to the degree of energy consumption reduction request, thereby reducing the energy consumption and reducing the frequency of thermo-off after the start of the cooling operation. be able to.

  An air conditioner according to a third aspect of the present invention is the air conditioner according to the first aspect or the second aspect, and further includes a correction amount setting unit. The correction amount setting unit sets a correction amount for the reference value of the upper limit target evaporation temperature. The target evaporation temperature determining unit changes the upper limit target evaporation temperature according to the correction amount set by the correction amount setting unit.

  Since this air conditioner includes a correction amount setting unit, the installer or user of the air conditioner can determine and set the correction amount according to the thermal environment of the installation location. Then, the upper limit target evaporation temperature is changed according to the correction amount, and effects such as suppression of the thermo-off frequency can be obtained.

  An air conditioner according to a fourth aspect of the present invention is the air conditioner according to any one of the first aspect to the third aspect, wherein the target evaporation temperature determining unit determines the above-described upper limit target from a predetermined lower limit target evaporation temperature. The target evaporation temperature is determined in the range up to the evaporation temperature.

  In this air survey device, in addition to the upper limit target evaporation temperature, the lower limit target evaporation temperature is also held, and the target evaporation temperature is determined within a temperature range determined by these. As a result, the target evaporation temperature does not fall below the lower limit target evaporation temperature, and the problem that the evaporator freezes can be suppressed.

  In the air conditioner according to the first aspect of the present invention, since the target evaporation temperature when switching from the start control to the cooling operation control is determined based on the outside air temperature, it is possible to suppress the problem of thermo-off immediately after the start of the cooling operation. Is possible. Moreover, since the upper limit target evaporation temperature can be changed by setting, it is possible to further suppress the problem of thermo-off immediately after the start of the cooling operation.

  In the air conditioning apparatus according to the second aspect of the present invention, the target evaporation temperature determination unit can change the upper limit target evaporation temperature according to the degree of energy consumption reduction request, thereby reducing the energy consumption. The frequency of thermo-off after the start of cooling operation can also be reduced.

  In the air conditioner according to the third aspect of the present invention, effects such as suppression of the thermo-off frequency and energy saving can be obtained.

  In the air conditioner according to the fourth aspect of the present invention, it is possible to suppress the problem that the evaporator freezes.

The schematic block diagram of the air conditioning apparatus which concerns on one Embodiment of this invention. The control block diagram of an air conditioning apparatus. The initial control flow figure which determines the initial target evaporation temperature TeS in air_conditionaing | cooling operation. A graph which shows correlation with initial target evaporation temperature TeS and outside air temperature Ta.

  Hereinafter, an air conditioner 1 according to an embodiment of the present invention will be described with reference to the drawings. In addition, the specific structure of the air conditioning apparatus which concerns on this invention is not restricted to the following embodiment and its modification, It can change in the range which does not deviate from the summary of invention.

(1) Overall Configuration of Air Conditioner FIG. 1 is a schematic configuration diagram of the air conditioner 1. The air conditioner 1 is an apparatus used for indoor air conditioning by performing a vapor compression refrigeration cycle operation. The air conditioner 1 is an air conditioner having a structure capable of performing each operation of cooling and heating. Here, the air conditioner 1 is used as an apparatus dedicated to cooling for cooling a facility that generates heat generated indoors. An example will be described.

  The air conditioner 1 is mainly configured by connecting an outdoor unit 2 and an indoor unit 4a. Here, the outdoor unit 2 and the indoor unit 4 a are connected via a liquid refrigerant communication tube 6 and a gas refrigerant communication tube 7. That is, the vapor compression refrigerant circuit 10 of the air conditioner 1 is configured by connecting the outdoor unit 2 and the indoor unit 4 a via the refrigerant communication pipes 6 and 7.

(2) Detailed Configuration of Air Conditioner (2-1) Indoor Unit The indoor unit 4a installed indoors mainly has an indoor refrigerant circuit 10a that constitutes a part of the refrigerant circuit 10. The indoor refrigerant circuit 10a mainly has an indoor expansion valve 41a and an indoor heat exchanger 42a.

  The indoor expansion valve 41a is a valve that adjusts the flow rate of the refrigerant by reducing the pressure of the refrigerant flowing through the indoor refrigerant circuit 10a. The indoor expansion valve 41a is an electric expansion valve connected to the liquid side of the indoor heat exchanger 42a.

  The indoor heat exchanger 42a is, for example, a cross fin type fin-and-tube heat exchanger. An indoor fan 43a for sending indoor air to the indoor heat exchanger 42a is provided in the vicinity of the indoor heat exchanger 42a. By blowing indoor air to the indoor heat exchanger 42a by the indoor fan 43a, the indoor heat exchanger 42a performs heat exchange between the refrigerant and the indoor air. The indoor fan 43a is rotationally driven by an indoor fan motor 44a. Thereby, the indoor heat exchanger 42a functions as a refrigerant evaporator.

  Various sensors are provided in the indoor unit 4a. On the liquid side of the indoor heat exchanger 42a, a liquid side temperature sensor 45a that detects the temperature of the refrigerant is provided. On the gas side of the indoor heat exchanger 42a, a gas side temperature sensor 46a for detecting the temperature of the refrigerant in the gas state is provided. On the indoor air inlet side of the indoor unit 4a, an indoor temperature sensor 47a that detects the temperature of the indoor air in the conditioned space targeted by the indoor unit 4a (that is, the indoor temperature) is provided. Moreover, the indoor unit 4a has the indoor side control apparatus 48a which controls operation | movement of each part which comprises the indoor unit 4a. And the indoor side control apparatus 48a has a microcomputer, memory, etc. provided in order to control the indoor unit 4a, and controls between the remote controllers 49a for operating the indoor unit 4a separately. Signals and the like can be exchanged, and control signals and the like can be exchanged with the outdoor unit 2. Note that the remote controller 49a is a device that allows the user to make various settings related to the air conditioning operation and to run / stop commands.

(2-2) Outdoor Unit The outdoor unit 2 installed outdoors mainly has an outdoor refrigerant circuit 10 c that constitutes a part of the refrigerant circuit 10. The outdoor refrigerant circuit 10c mainly includes a compressor 21, a switching mechanism 22, an outdoor heat exchanger 23, and an outdoor expansion valve 24.

  The compressor 21 is a hermetic compressor in which a compression element (not shown) and a compressor motor 20 that rotationally drives the compression element are accommodated in a casing. The compressor motor 20 is supplied with electric power via an inverter device (not shown), and the operating capacity is varied by changing the frequency of the inverter device (that is, the rotation speed of the compressor motor 20). Be able to.

  The switching mechanism 22 is a four-way switching valve for switching the direction of refrigerant flow. The switching mechanism 22 functions as a radiator for the refrigerant compressed in the compressor 21 and as an evaporator for the refrigerant that radiates heat in the outdoor heat exchanger 23 during the cooling operation. In order to achieve this, the discharge side piping of the compressor 21 and the gas side of the outdoor heat exchanger 23 are connected, and the suction side piping of the compressor 21 and the gas refrigerant communication tube 7 are connected (the switching mechanism of FIG. 1). (See 22 solid line). Although the heating operation can be performed by switching the switching mechanism 22, the air-conditioning apparatus 1 is used as a cooling-only device here, and thus the description during the heating operation is omitted.

  The outdoor heat exchanger 23 is, for example, a cross fin type fin-and-tube heat exchanger. An outdoor fan 25 for sending outdoor air to the outdoor heat exchanger 23 is provided in the vicinity of the outdoor heat exchanger 23. By blowing outdoor air to the outdoor heat exchanger 23 by the outdoor fan 25, the outdoor heat exchanger 23 performs heat exchange between the refrigerant and the outdoor air. The outdoor fan 25 is rotationally driven by an outdoor fan motor 26. Thereby, the outdoor heat exchanger 23 functions as a radiator of the refrigerant.

  The outdoor expansion valve 24 is a valve that depressurizes the refrigerant flowing through the outdoor refrigerant circuit 10c. The outdoor expansion valve 24 is an electric expansion valve connected to the liquid-side piping of the outdoor heat exchanger 23, and is adjusted so as to keep the pressure value of the high-pressure refrigerant within a predetermined range together with the outdoor fan 25 in the cooling operation.

  The outdoor unit 2 is provided with various sensors. The outdoor unit 2 includes a suction pressure sensor 31 that detects the suction pressure of the compressor 21, a discharge pressure sensor 32 that detects the discharge pressure of the compressor 21, and a suction temperature sensor 33 that detects the suction temperature of the compressor 21. A discharge temperature sensor 34 for detecting the discharge temperature of the compressor 21 is provided. The outdoor heat exchanger 23 is provided with an outdoor heat exchange temperature sensor 35 that detects the temperature of the refrigerant in the gas-liquid two-phase state. The liquid side pipe of the outdoor heat exchanger 23 is provided with a liquid side temperature sensor 36 for detecting the temperature of the refrigerant in the liquid state. An outdoor air temperature sensor 37 that detects the temperature of the outdoor air in the external space where the outdoor unit 2 is disposed (that is, the outdoor air temperature Ta) is provided on the outdoor air inlet side of the outdoor unit 2. The outdoor unit 2 has an outdoor side control device 38 that controls the operation of each part constituting the outdoor unit 2. The outdoor side control device 38 includes a microcomputer provided to control the outdoor unit 2, an inverter device for controlling the memory and the compressor motor 20, and the like, and the indoor side control device of the indoor unit 4 a. Control signals and the like can be exchanged with 48a.

(2-3) Refrigerant communication pipes The refrigerant communication pipes 6 and 7 are refrigerant pipes that are constructed on site when the air conditioner 1 is installed, depending on the installation conditions of the outdoor unit 2 and the indoor unit 4a. Those having various lengths and pipe diameters are used.

(2-4) Control Device The remote controller 49a for operating the indoor unit 4a, the indoor side control device 48a of the indoor unit 4a, and the outdoor side control device 38 of the outdoor unit 2 are connected by wire or wirelessly, The control apparatus 8 which performs operation control of the air conditioning apparatus 1 whole is comprised. As shown in FIG. 2, the control device 8 is connected to these sensors 31 to 37, 45 a, 46 a, 47 a and the like so as to receive detection signals. And the control apparatus 8 performs air_conditionaing | cooling operation etc. by controlling various apparatuses and valves 20, 22, 24, 26, 41a, 44a based on these detection signals.

  In addition, the control device 8 includes, as function units of a program built in the microcomputer, a startup control unit 81, a cooling operation control unit 82, a target evaporation temperature determination unit 83, an energy saving request setting unit 84, a correction amount setting unit 85, and a thermo control. Part 86, and the like.

(2-4-1) Startup Control Unit The startup control unit 81 that performs startup control drives the compressor 21 at a predetermined rotational speed for a predetermined period immediately after the startup of the air conditioning apparatus 1. Specifically, the rotational speed is gradually increased while increasing the inverter frequency stepwise for a predetermined period. In the activation control, the opening degree of the indoor expansion valve 41a is controlled so as to increase gradually.

(2-4-2) Cooling Operation Control Unit The cooling operation control unit 82 that performs the cooling operation control is configured so that the refrigerant evaporation temperature Te in the indoor heat exchanger 42a of the indoor unit 4a approaches the target evaporation temperature TeS. The operating capacity of the compressor 21 is adjusted by adjusting the rotational speed of the compressor 21.

(2-4-3) Target Evaporation Temperature Determination Unit The target evaporation temperature determination unit 83 sets the target evaporation temperature TeS at the start of the cooling operation, that is, the target at the initial stage of the cooling operation when switching from the startup control to the cooling operation control. The evaporation temperature TeS is determined based on the outside air temperature Ta. The target evaporation temperature determining unit 83 determines the target evaporation temperature TeS within a range that does not exceed the upper limit target evaporation temperature W and that does not fall below the lower limit target evaporation temperature Q. Specifically, the target evaporation temperature TeS is determined by the following formula 1.
Formula 1: TeS = −A × Ta + B
However,
A: Coefficient B: Coefficient TeS> Lower limit target evaporation temperature Q (fixed value)
TeS <upper limit target evaporation temperature W (variable value)

The upper limit target evaporation temperature W is a variable value and is calculated by the following equation 2.
Formula 2: W = C + V
C: Variable V: Variable

  The variables C and V are determined by the energy saving request setting unit 84 and the correction amount setting unit 85 described below.

(2-4-4) Energy Saving Request Setting Unit The energy saving request setting unit 84 receives a setting input by the user from the remote controller 49a, and sets the power consumption reduction request level. Here, either “strong energy saving” or “weak energy saving” is set as the degree of the reduction request indicating the energy saving level. When “strong energy saving” is selected in the energy saving request setting unit 84, the upper limit target evaporation temperature W increases by 1 ° C. than when “weak energy saving” is selected. Specifically, the variable C in the calculation formula (formula 2) for the upper limit target evaporation temperature W is increased by one. That is, the target evaporation temperature determination unit 83 changes the upper limit target evaporation temperature W according to the power consumption reduction request degree set by the energy saving request setting unit 84.

(2-4-5) Correction amount setting unit The correction amount setting unit 85 sets a correction amount for the reference value (variable C) of the upper limit target evaporation temperature W. Specifically, the variable V of the calculation formula for the upper limit target evaporation temperature W is set as the correction amount. This setting is performed by an installer (installer of the air conditioner 1) or a user in an initial setting performed when the air conditioner 1 is installed. Although the default variable V is 0 ° C., the variable V can be set in several steps up to 15 ° C. by setting in the correction amount setting unit 85.

  When the indoor temperature in the indoor unit 4a reaches the set temperature of the indoor temperature in the indoor unit 4a, the thermo control unit 86 stops the cooling operation of the indoor unit 4a (indoor thermo-off) and stops the compressor 21 ( Outdoor thermo-off). More specifically, the thermo temperature range is set with respect to the set temperature of the room temperature, and the thermo is turned off when the room temperature becomes lower than the set temperature exceeding the thermo temperature range. If the thermo-temperature range is ± 0.5 ° C. and the set temperature is 24.0 ° C., the thermo-off is performed when the room temperature falls below 23.5 ° C. On the other hand, when the indoor temperature in the indoor unit 4a in the indoor thermo-off state deviates from the thermo-temperature range, the cooling operation is resumed (thermo-on). In the thermo-off state, the flow of the refrigerant in the refrigerant circuit 10 is stopped, and the air conditioner 1 is substantially in a state where all the operations are stopped although the command for the cooling operation is continued.

  In the indoor unit 4a, the indoor expansion valve 41a and the indoor fan motor 44a of the indoor unit 4a are controlled so that the room temperature becomes a set temperature that is a target value of the room temperature.

(3) Operation | movement of an air conditioning apparatus (3-1) Basic operation Next, the basic operation | movement of the cooling operation of the air conditioning apparatus 1 is demonstrated using FIG.

  When a cooling operation command is issued from the remote controller 49a, the compressor 21, the outdoor fan 25, and the indoor fan 43a are activated. As described above, the start-up control for driving the compressor 21 at a predetermined number of revolutions is performed for a predetermined period, and then the cooling operation is performed.

  In the cooling operation, the low-pressure gas refrigerant in the refrigerant circuit 10 is sucked into the compressor 21 and compressed to become a high-pressure gas refrigerant. The high-pressure gas refrigerant is sent to the outdoor heat exchanger 23 via the switching mechanism 22. The high-pressure gas refrigerant sent to the outdoor heat exchanger 23 is cooled by exchanging heat with outdoor air supplied by the outdoor fan 25 in the outdoor heat exchanger 23 functioning as a refrigerant radiator. The high-pressure liquid refrigerant cooled and condensed by the outdoor heat exchanger 23 is sent from the outdoor unit 2 to the indoor unit 4a via the outdoor expansion valve 24 and the liquid refrigerant communication pipe 6.

  The high-pressure liquid refrigerant sent to the indoor unit 4a is decompressed by the indoor expansion valve 41a, and becomes a low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant is sent to the indoor heat exchanger 42a. The low-pressure gas-liquid two-phase refrigerant sent to the indoor heat exchanger 42a is heated by exchanging heat with the indoor air supplied by the indoor fan 43a in the indoor heat exchanger 42a functioning as an evaporator of the refrigerant. Is done. The low-pressure gas refrigerant heated and evaporated by the indoor heat exchanger 42 a is sent from the indoor unit 4 a to the outdoor unit 2 via the gas refrigerant communication pipe 7.

  The low-pressure gas refrigerant sent to the outdoor unit 2 is again sucked into the compressor 21 via the switching mechanism 22.

(3-2) Cooling Operation Control In the cooling operation, the air conditioning capability of the outdoor unit 2 (that is, the operating capacity of the compressor 21) is controlled so that the refrigerant evaporation temperature Te in the refrigerant circuit 10 approaches the target evaporation temperature TeS. The Further, the indoor expansion valve 41a and the indoor fan motor 44a of the indoor unit 4a are controlled so that the indoor temperature in the indoor unit 4a approaches the set temperature of the indoor temperature in the indoor unit 4a. The set temperature of the indoor temperature in the indoor unit 4a is input and set by the remote controller 49a. Further, when the cooling operation control unit 82 is performing the cooling operation control, the control of the air conditioning capability of the outdoor unit 2 is performed by the outdoor control device 38 of the control device 8, and the control of the indoor unit 4 a is controlled by the control device 8. The indoor side control device 48a takes charge.

  In the cooling operation control, the cooling operation control unit 82 controls the opening degree of the indoor expansion valve 41a so that the superheat degree of the refrigerant at the outlet of the indoor heat exchanger 42a becomes the target superheat degree. Here, the degree of superheat is calculated from the suction pressure detected by the suction pressure sensor 31 and the temperature of the refrigerant on the gas side of the indoor heat exchanger 42a detected by the gas side temperature sensor 46a. More specifically, first, the suction pressure obtained from the suction pressure sensor 31 is converted into the saturation temperature of the refrigerant to obtain the evaporation temperature Te, which is a state quantity equivalent to the evaporation pressure Pe in the refrigerant circuit 10. Here, the evaporation pressure Pe means the pressure of the low-pressure refrigerant that flows between the outlet of the indoor expansion valve 41a and the intake side piping of the compressor 21 through the indoor heat exchanger 42a in the cooling operation. doing. Then, the degree of superheat is obtained by subtracting the evaporation temperature Te from the temperature of the refrigerant on the gas side of the indoor heat exchanger 42a.

  In the cooling operation control, the cooling operation control unit 82 controls the operation capacity of the compressor 21 so that the above-described evaporation temperature Te in the refrigerant circuit 10 approaches the target evaporation temperature TeS. Here, the operation capacity of the compressor 21 is adjusted by changing the inverter frequency of the compressor motor 20. Here, the state quantity to be controlled is the evaporation temperature Te, but it may be the evaporation pressure Pe corresponding to the evaporation temperature Te. In this case, a target evaporation pressure PeS corresponding to the target evaporation temperature TeS may be used. That is, the evaporating pressure Pe and the evaporating temperature Te, and the target evaporating pressure PeS and the target evaporating temperature TeS mean substantially the same state quantity, although the words themselves are different.

  Thus, in the cooling operation, as the basic control, superheat degree control by the indoor expansion valve 41a and evaporation temperature control by the compressor 21 are performed.

  Note that the target evaporation temperature TeS in the cooling operation control is updated every several tens of seconds based on the indoor temperature set temperature and the outside air temperature Ta in the indoor unit 4a. Specifically, the target evaporation temperature TeS is set lower as the temperature difference between the set temperature of the room temperature and the outside air temperature Ta is larger. As a result, the repetition frequency of the thermo-on / thermo-off is reduced and the energy-saving performance of the air conditioner 1 is improved, but the room temperature is set by the amount that the air-conditioning capacity of the outdoor unit 2 tends to be suppressed. There is a tendency that the time until the temperature is reached tends to be long, and the comfort may be impaired. The above-described energy saving request setting unit 84 is provided mainly for users who desire to improve this comfort.

(3-3) Determination of Initial Target Evaporation Temperature TeS in Cooling Operation Next, with reference to FIG. 3, an initial target evaporation temperature TeS (a target evaporation temperature when switching from start-up control to cooling operation control) Hereinafter, determination of initial TeS) will be described. By the determination of the initial TeS by the target evaporation temperature determination unit 83, the initial TeS varies according to the outside air temperature Ta as shown by a thick solid line in FIG.

  As shown in FIG. 3, in the initial control of the cooling operation, it is first determined whether or not the start control satisfies the end condition (step S11). For example, when the condition that a predetermined period of several minutes has passed is satisfied, the process proceeds from step S11 to step S12.

  In step S12, the target evaporating temperature determination unit 83 acquires information on the outside air temperature Ta from the outside air temperature sensor 37, and uses the outside air temperature Ta to calculate a temporary target according to the above-described formula 1 (TeS = −A × Ta + B). An evaporation temperature (hereinafter referred to as temporary TeS) is calculated.

  Next, in step S13, the target evaporation temperature determination unit 83 determines whether or not the temporary TeS is below the lower limit target evaporation temperature Q. If it is lower, the process proceeds to step S14, and the initial TeS is determined as the lower limit target evaporation temperature Q (initial TeS = Q).

  If the temporary TeS is equal to or higher than the lower limit target evaporation temperature Q in step S13, the target evaporation temperature determination unit 83 proceeds to step S15, and the variable C based on the setting of the reduction request degree of the power consumption amount in the energy saving request setting unit 84 is set. While acquiring a value, the value of the variable V which is the correction amount set in the correction amount setting part 85 is acquired. Then, based on the values of these variables C and V, the upper limit target evaporation temperature W is calculated by the above-described equation 2 (W = C + V).

  Next, in step S16, the target evaporation temperature determining unit 83 determines whether or not the temporary TeS calculated in step S12 exceeds the upper limit target evaporation temperature W. When the temporary TeS exceeds the upper limit target evaporation temperature W, the process proceeds to step S17, and the initial TeS is determined as the upper limit target evaporation temperature W (initial TeS = W).

  If the temporary TeS is equal to or lower than the upper limit target evaporation temperature W in step S16, the target evaporation temperature determining unit 83 proceeds to step S18 and sets the value of temporary TeS to initial TeS. That is, if the value of the temporary TeS is in the range from the lower limit target evaporation temperature Q to the upper limit target evaporation temperature W, the temporary TeS calculated based on the outside air temperature Ta becomes the initial TeS.

  In step S19, the cooling operation control unit 82 starts adjusting the inverter frequency of the compressor 21 so that the refrigerant evaporation temperature Te approaches the initial TeS determined in step S14, step S17, or step S18.

  Thereafter, as described above, the cooling operation control unit 82 updates the target evaporation temperature TeS every several tens of seconds based on the set temperature of the indoor temperature in the indoor unit 4a and the outside air temperature Ta, and supplies the refrigerant to the target evaporation temperature TeS. The inverter frequency of the compressor 21 is continuously adjusted so that the evaporating temperature Te approaches.

(4) Features (4-1)
In the air conditioning apparatus 1 according to the present invention, immediately after startup, startup control by the startup control unit 81 is performed, and the compressor 21 is driven at a predetermined rotational speed. Thereafter, when the start-up control ends, the operation mode is switched to the cooling operation control. The target evaporation temperature TeS (initial TeS) at that time is determined by the target evaporation temperature determination unit 83 based on the outside air temperature Ta. Specifically, in view of the tendency of the cooling capacity to increase as the outside air temperature Ta decreases, the initial equation (TeS = −A × Ta + B) is initially set so that the initial TeS decreases as the outside air temperature Ta decreases. TeS is calculated.

  For this reason, for example, even when the air conditioner 1 is installed in a cold region and the cooling operation is performed with the outside air temperature Ta being low, the initial TeS that is the target evaporation temperature at the start of the cooling operation can be determined high. . As a result, when the outside air temperature Ta is lower than when the outside air temperature Ta is high, the initial TeS at the start of the cooling operation becomes higher, and the air conditioner 1 is thermo-off immediately after the start of the cooling operation. It is suppressed.

  Further, in this air conditioner 1, the initial TeS is determined in a range that does not exceed the upper limit target evaporation temperature W based on the setting value set by the user or the installer using the energy saving request setting unit 84 or the correction amount setting unit 85. If the upper limit target evaporation temperature W is a fixed value, for example, 8 ° C., the initial TeS is 8 even when the air conditioner 1 is installed in an area where the outside air temperature Ta is very low and the cooling capacity is excessive. There is an upper limit at 0 ° C., and it is highly likely that the air conditioner 1 is thermo-off after a while after the start of the cooling operation.

  However, in the air conditioner 1, the energy saving request setting unit 84 and the correction amount setting unit 85 are provided, and the upper limit target evaporation temperature W can be changed according to the installation environment. Thereby, the malfunction that the air conditioning apparatus 1 thermo-offs immediately after the air_conditionaing | cooling operation start is suppressed more.

(4-2)
In the air conditioner 1 according to the present invention, in the cooling operation, the target evaporation temperature TeS is basically set lower as the temperature difference between the set temperature of the indoor unit 4a and the outside air temperature Ta is larger. When such adjustment of the target evaporation temperature TeS is performed, the target evaporation temperature TeS increases when the demand for the air conditioning capacity from the indoor unit 4a is small (when the set temperature is high). Excessive amount is suppressed. Thereby, the operation / stop of the indoor unit 4a and the compressor 21, that is, the repetition frequency of the thermo-on / thermo-off of the air conditioner 1, is reduced, and the energy saving is improved.

  However, on the other hand, as the air conditioning capacity of the outdoor unit 2 tends to be suppressed, the time until the room temperature reaches the set temperature tends to be longer, and the comfort may be impaired. .

  As described above, only adjusting the target evaporation temperature TeS according to the air conditioning load can satisfy the user who prioritizes energy saving, but it is difficult to satisfy the user who prioritizes comfort. In the harmony device 1, an energy saving request setting unit 84 is provided. The user can select either “strong energy saving” or “weak energy saving” from the remote controller 49a. If the user who gives priority to comfort selects “weak energy saving”, the upper limit target evaporating temperature W is lowered by 1 ° C. compared to the case where “strong energy saving” is selected, and comfort can be improved. When “strong energy saving” is set in the energy saving request setting unit 84, the upper limit target evaporation temperature W becomes higher, the power consumption can be reduced, and the frequency of thermo-off after the start of the cooling operation can be further reduced. it can.

(4-3)
In the air conditioning apparatus 1 according to the present invention, a correction amount setting unit 85 is provided in order to make it possible to greatly change the upper limit target evaporation temperature W. The user or the installer of the air conditioner 1 can input and set a variable V that is a correction amount with respect to the reference value (variable C) of the upper limit target evaporation temperature W. Then, the target evaporation temperature determination unit 83 calculates the upper limit target evaporation temperature W according to the above equation 2 (W = C + V) according to the correction amount (variable V) set by the correction amount setting unit 85.

  For this reason, the user of the air conditioning apparatus 1 can determine and input the variable V, which is a correction amount, according to the thermal environment of the installation location, the electricity charge, and the like. And by changing the upper limit target evaporation temperature W according to this correction amount, effects such as suppression of the thermo-off frequency of the air-conditioning apparatus 1 and saving of electricity bills can be obtained.

(4-4)
In the air conditioner 1 according to the present invention, in addition to the upper limit target evaporation temperature W, the lower limit target evaporation temperature Q is also held in the memory of the control device 8, and a temperature range determined by these (Q or more and W or less). The target evaporation temperature TeS is determined in FIG. As a result, the initial TeS, which is the target evaporation temperature TeS at the initial stage of the cooling operation, does not fall below the lower limit target evaporation temperature Q (see steps S13 and S14 in FIG. 3), and the inconvenience that the indoor heat exchanger 42a is frozen is suppressed. Is able to.

(5) Modification (5-1) Modification 1A
In the above-described embodiment, an example in which the present invention is applied to the air conditioner 1 including one outdoor unit 2 and one indoor unit 4a has been described. However, a multi-unit in which a plurality of indoor units are connected to one outdoor unit. The present invention can also be applied to a type of air conditioner.

  In the above embodiment, the air conditioner 1 is described as an apparatus dedicated to cooling. However, the present invention can also be applied to the air conditioner 1 that can switch between cooling and heating.

(5-2) Modification 1B
In the above embodiment, the initial TeS is determined within the range from the lower limit target evaporation temperature Q to the upper limit target evaporation temperature W based on the outside air temperature Ta.

  However, in addition to the upper limit target evaporation temperature W, a second upper limit target evaporation temperature based on the set temperature of the indoor temperature in the indoor unit 4a is provided, and from the start control to the cooling operation so as not to exceed these two upper limit target evaporation temperatures The initial TeS when switching to control may be determined. In this case, the comfort of the user of the air conditioning apparatus 1 is further improved.

(5-3) Modification 1C
In the above embodiment, the target evaporation temperature determining unit 83 determines the initial TeS immediately after the start control, but the determination timing may be earlier. That is, the target evaporation temperature determination unit 83 may determine the initial TeS during the startup control.

(5-4) Modification 1D
In the above embodiment, the outdoor unit 2 is provided with the outdoor temperature sensor 37 to acquire the outdoor temperature Ta. However, if the air conditioning apparatus 1 has been stopped for a long time, the target evaporation temperature determination unit 83 acquires the outdoor air temperature Ta from the outdoor heat exchanger temperature sensor 35 provided in the outdoor heat exchanger 23 immediately after startup. Can do. That is, the outside temperature sensor 37 is not an essential component, and the outside temperature Ta can be obtained if the outdoor heat exchange temperature sensor 35 or the suction temperature sensor 33 is provided.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 21 Compressor 81 Start-up control part 82 Cooling operation control part 83 Target evaporation temperature determination part 84 Energy saving requirement setting part 85 Correction amount setting part Ta Outside air temperature Te Evaporation temperature TeS Target evaporation temperature Q Lower limit target evaporation temperature W Upper limit target Evaporation temperature

JP 2002-147823 A

Claims (4)

A cooling operation control unit (82) that adjusts the rotation speed of the compressor (21) so that the refrigerant evaporation temperature (Te) approaches the target evaporation temperature (TeS), performs cooling operation control, and
An activation control unit (81) for performing activation control for driving the compressor at a predetermined rotational speed for a predetermined period immediately after activation;
A target evaporation temperature determining unit (83) for determining the target evaporation temperature (initial TeS) when the activation control is switched to the cooling operation control based on the outside air temperature (Ta);
With
The target evaporation temperature determining unit (83) determines the target evaporation temperature in a range not exceeding an upper limit target evaporation temperature (W) that can be changed by setting.
Air conditioner (1). Energy saving request setting unit (84) for setting the degree of energy consumption reduction request,
Further comprising
The target evaporation temperature determining unit (83) changes the upper limit target evaporation temperature in accordance with a reduction request degree of the energy consumption set by the energy saving request setting unit (84).
The air conditioner (1) according to claim 1. A correction amount setting unit (85) for setting a correction amount (V) with respect to a reference value of the upper limit target evaporation temperature,
Further comprising
The target evaporation temperature determining unit (83) changes the upper limit target evaporation temperature according to the correction amount (V) set by the correction amount setting unit (85).
The air conditioner (1) according to claim 1 or 2. The target evaporation temperature determining unit (83) determines the target evaporation temperature in a range from a predetermined lower limit target evaporation temperature (Q) to the upper limit target evaporation temperature (W).
The air conditioner (1) according to any one of claims 1 to 3.

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