Air conditioner and method for controlling same

Abstract

The present invention relates to an air conditioner for supplying hot water while cooling or heating an indoor space, and a method for controlling same. The air conditioner according to an embodiment of the present invention comprises: a compressor compressing a refrigerant; an outdoor heat exchanger condensing the refrigerant compressed by the compressor; an indoor expansion valve expanding the refrigerant condensed by the outdoor heat exchanger; an indoor heat exchanger evaporating the refrigerant expanded by the indoor expansion valve; a hot water heat exchanger exchanging heat between the refrigerant compressed by the compressor and water to condense the refrigerant; a high pressure sensor measuring a discharge pressure which is the pressure of the refrigerant compressed by the compressor; a water inlet temperature sensor measuring a water inlet temperature which is the temperature of water introduced into the hot water heat exchanger; a water outlet temperature sensor measuring a water outlet temperature which is the temperature of water discharged from the hot water heat exchanger; and a control unit controlling the compressor such that the discharge pressure becomes a target pressure set according to the water inlet temperature.

Description

Air conditioner and control method thereof

[0001] The present invention relates to an air conditioner and a method for controlling the same, and more specifically, to an air conditioner that cools or heats an indoor space and supplies hot water, and a method for controlling the same.

[0002] Generally, air conditioners cool and heat indoor spaces by circulating refrigerant. Air conditioners are classified into single-type air conditioners, where one indoor unit is connected to the outdoor unit, and multi-type air conditioners, where multiple indoor units are connected to the outdoor unit, depending on the number of indoor units connected.

[0003] Multi-unit air conditioners are classified into switching type and simultaneous type based on the refrigerant flow method. Switching type air conditioners operate all indoor units either in cooling mode or heating mode. Simultaneous type air conditioners operate some indoor units in cooling mode and some indoor units in heating mode simultaneously.

[0004] A synchronous air conditioner is equipped with a distributor that distributes refrigerant to multiple indoor units. The distributor distributes compressed and condensed refrigerant to each indoor unit so that each indoor unit can operate in cooling mode or heating mode.

[0005] In addition to the indoor unit, a water heater can be connected to this synchronous air conditioner, which generates hot water by heat-exchanging water and refrigerant and then supplies the generated hot water to a water tank, underfloor heating, radiator, fan coil unit, or faucet.

[0006] In these simultaneous hot water supply air conditioners, when indoor cooling and hot water supply are combined, the heat dissipation capacity of the outdoor heat exchanger decreases when the outdoor temperature is high. Furthermore, as the inlet temperature of the water heater rises, the heat dissipation capacity of the water heater also decreases, resulting in a decrease in overall condensation efficiency. Consequently, there was a problem of performance degradation as the high pressure increased, limiting the operation of the compressor.

[0007] The problem that the present invention aims to solve is to provide an air conditioner and a control method thereof in which cooling performance and discharge water temperature do not decrease even when the outdoor temperature is high.

[0008] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below.

[0009] To achieve the above objective, an air conditioner according to an embodiment of the present invention comprises: a compressor for compressing a refrigerant; an outdoor heat exchanger for condensing the refrigerant compressed by the compressor; an indoor expansion valve for expanding the refrigerant condensed by the outdoor heat exchanger; an indoor heat exchanger for evaporating the refrigerant expanded by the indoor expansion valve; a hot water heat exchanger for condensing the refrigerant compressed by the compressor by heat exchange with water; a high-pressure sensor for measuring the discharge pressure, which is the pressure of the refrigerant compressed by the compressor; an inlet temperature sensor for measuring the inlet temperature, which is the temperature of water entering the hot water heat exchanger; an outlet temperature sensor for measuring the outlet temperature, which is the temperature of water discharged from the hot water heat exchanger; and a control unit for controlling the compressor so that the discharge pressure becomes a target pressure set according to the inlet temperature.

[0010] To achieve the above objective, a control method for an air conditioner according to an embodiment of the present invention comprises: a step of determining whether it is a performance mode or an efficiency mode based on an increment of the discharge temperature, which is the temperature of water discharged from the hot water heat exchanger, and the inlet temperature, which is the temperature of water entering the hot water heat exchanger; a step of, in the case of the performance mode, setting the target pressure, which is the pressure of the refrigerant compressed in the compressor, and the inlet temperature in a limited linear relationship having a set performance coefficient; and, in the case of the efficiency mode, setting the target pressure and the inlet temperature in a limited linear relationship having a set efficiency coefficient, wherein the performance coefficient is greater than the efficiency coefficient.

[0011] Specific details of other embodiments are included in the detailed description and drawings.

[0012] According to the air conditioner and the control method thereof of the present invention, one or more of the following effects are provided.

[0013] First, it has the advantage of preventing a decrease in cooling performance by increasing the compressor's operating speed to secure the total refrigerant flow rate, even when the inlet temperature is high.

[0014] Second, it also has the advantage of reducing power consumption by limiting excessive compressor operation through setting a target pressure for the refrigerant discharged from the compressor according to the inlet temperature.

[0015] Third, there is also the advantage of being able to lower power consumption while increasing performance by controlling two modes, performance mode and efficiency mode, based on the difference between the water outlet temperature and the water inlet temperature.

[0016] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0017] FIG. 1 is a configuration diagram of an air conditioner according to one embodiment of the present invention.

[0018] FIG. 2 is a block diagram of an air conditioner according to one embodiment of the present invention.

[0019] FIG. 3 is a flowchart of a control method for an air conditioner according to one embodiment of the present invention.

[0020] FIG. 4 is a diagram showing the relationship between the target pressure and the inlet temperature in a control method of an air conditioner according to one embodiment of the present invention.

[0021] This is provided to fully inform those skilled in the art of the scope of the invention, and the invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0022] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0023] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0024] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0025] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0026] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0027] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less unless specifically stated otherwise.

[0028] Hereinafter, the present invention will be described with reference to the drawings for explaining an air conditioner and a control method thereof according to embodiments of the present invention.

[0029] FIG. 1 is a configuration diagram of an air conditioner according to one embodiment of the present invention, and FIG. 2 is a block diagram of an air conditioner according to one embodiment of the present invention.

[0030] An air conditioner according to one embodiment of the present invention comprises an outdoor unit (110) that compresses a refrigerant and exchanges heat between the refrigerant and outdoor air; a distributor (190) connected to the outdoor unit (110) and distributing the refrigerant compressed or condensed from the outdoor unit (110) to a plurality of indoor units (120) and a water heater (130); a plurality of indoor units (120) connected to the distributor (190) and cooling or heating the indoor space by exchanging heat between the refrigerant and indoor air; and a water heater (130) connected to the distributor (190) and heating the water by exchanging heat between the refrigerant and water.

[0031] The outdoor unit (110) includes a compressor (111) that compresses refrigerant, an outdoor heat exchanger (112) that condenses the refrigerant compressed by the compressor (111) or evaporates the refrigerant expanded by the outdoor expansion valve (113), an outdoor expansion valve (113) that expands the refrigerant condensed by the indoor heat exchanger (121) of the indoor unit (120), a switching valve (114) that switches the flow path of the refrigerant according to the operating mode to guide the refrigerant compressed by the compressor (111) to the outdoor heat exchanger (112) or guides the refrigerant evaporated by the outdoor heat exchanger (112) to the compressor (111), and a high-pressure sensor (115) that measures the discharge pressure, which is the pressure of the refrigerant compressed by the compressor (111).

[0032] Each of the multiple indoor units (120) expands the refrigerant during cooling operation to cool the indoor air, and condenses the refrigerant during heating operation to heat the indoor air.

[0033] Each of the plurality of indoor units (120) includes an indoor expansion valve (122) that expands the refrigerant condensed in the outdoor heat exchanger (112) of the outdoor unit (110), and an indoor heat exchanger (121) that condenses the refrigerant compressed in the compressor (111) of the outdoor unit (110) or evaporates the refrigerant expanded in the indoor expansion valve (122).

[0034] The water heater (130) includes a hot water heat exchanger (131) that condenses the refrigerant compressed in the compressor (111) by heat exchange with water, an inlet temperature sensor (132) that measures the inlet temperature of the water entering the hot water heat exchanger (131), and an outlet temperature sensor (133) that measures the outlet temperature of the water exiting the hot water heat exchanger (131).

[0035] The water heater (130) is connected to a hot water demand location (200) and heats water during hot water operation and supplies it to the hot water demand location (200). The hot water demand location (200) may be a radiator or fan coil unit that heats the room by receiving water heated from the hot water heat exchanger (131) of the water heater (130), may be a water tank that stores hot water, or may be a faucet that dispenses hot water.

[0036] The distributor (190) is connected to an outdoor unit (110), a plurality of indoor units (120), and a water heater (130), and the distributor (190) supplies refrigerant condensed from the outdoor heat exchanger (112) of the outdoor unit (110) to an indoor unit (120) operating in cooling mode, and supplies refrigerant compressed from the compressor (111) of the outdoor unit (110) to an indoor unit (120) and a water heater (130) operating in heating mode.

[0037] The control unit (10) switches the switching valve (114) according to the operating mode, controls the distributor (190) so that the refrigerant is distributed according to the operating mode, adjusts the opening degree of the outdoor expansion valve (113) and the indoor expansion valve (122) according to the operating conditions, and controls the operating speed (frequency) of the compressor (111) according to the discharge pressure measured by the high pressure sensor (115), the inlet temperature measured by the inlet temperature sensor (132), and the outlet temperature measured by the outlet temperature sensor (133).

[0038] The control unit (10) controls the compressor (111) so that the discharge pressure becomes a target high pressure set according to the inlet temperature. The control unit (10) sets the target high pressure and the inlet temperature as a bounded linear relationship. A bounded linear relationship means that the target high pressure has a lower limit and an upper limit, and is in a linear relationship with the inlet temperature between the lower limit and the upper limit. Although the high pressure and the condensation temperature form a saturation curve on the pH diagram (Mollier diagram), the saturation curve is generally approximated linearly within the operating range of the compressor (111), so a linear relationship is established between the target high pressure and the inlet temperature. However, when the inlet temperature is very low, the target high pressure may become excessively low, causing the refrigerant flow rate to become unstable, so a lower limit is required; and when the inlet temperature is very high, the target high pressure may become excessively high, causing damage to the compressor, so an upper limit is required. The control unit (10) sets the range of the target high pressure differently according to the increment of the outlet temperature and the inlet temperature.

[0039] The control unit (10) determines whether it is a performance mode or an efficiency mode based on the increment of the discharge temperature and the inlet temperature, and if it is a performance mode, sets the target high pressure and the inlet temperature to a limited linear relationship with a set performance coefficient, and if it is an efficiency mode, sets the target high pressure and the inlet temperature to a limited linear relationship with a set efficiency coefficient.

[0040] A detailed explanation of this will be provided later with reference to Figs. 3 and 4.

[0041] Referring to FIG. 1, the operation of the air conditioner when multiple indoor units (120) are all operating in cooling mode and the water heater (130) is operating in hot water mode is explained as follows.

[0042] A portion of the refrigerant compressed in the compressor (111) flows to the outdoor heat exchanger (112) through the switching valve (114). The refrigerant flowing to the outdoor heat exchanger (112) condenses by exchanging heat with the outdoor air. The refrigerant condensed in the outdoor heat exchanger (112) passes through the fully open outdoor expansion valve (113) and then flows to the distributor (190).

[0043] Another portion of the refrigerant compressed in the compressor (111) flows to the distributor (190). The compressed refrigerant flowing to the distributor (190) flows to the water heater (130). The refrigerant flowing to the water heater (130) exchanges heat with water in the hot water heat exchanger (131) and condenses to heat the water. The refrigerant condensed in the hot water heat exchanger (131) flows to the distributor (190).

[0044] The refrigerant condensed in the outdoor heat exchanger (112) and the hot water heat exchanger (131), which flows through the distributor (190), is distributed from the distributor (190) to each of the plurality of indoor units (120). The refrigerant flowing to each of the plurality of indoor units (120) is expanded in the indoor expansion valve (122) and then evaporates by exchanging heat with the indoor air in the indoor heat exchanger (121) to cool the indoor space. The refrigerant evaporated in the indoor heat exchanger (121) flows to the compressor (111) through the distributor (190). According to the embodiment, the refrigerant condensed in the hot water heater (130) may flow to the compressor (111) through the distributor (190).

[0045] FIG. 3 is a flowchart of a control method for an air conditioner according to one embodiment of the present invention, and FIG. 4 is a diagram showing the relationship between the target pressure and the inlet temperature in a control method for an air conditioner according to one embodiment of the present invention.

[0046] A control method for an air conditioner according to one embodiment of the present invention comprises: a step (S1) of operating a plurality of indoor units (120) in a cooling mode and operating a water heater (130) in a hot water mode; a step (S2, S9) of determining whether it is a performance mode or an efficiency mode based on an increment (Δt) of the discharge temperature, which is the temperature of water discharged from a hot water heat exchanger (131), and the inlet temperature, which is the temperature of water entering the hot water heat exchanger (131); a step (S3 to S7) of setting the target pressure and the inlet temperature for the discharge pressure, which is the pressure of the refrigerant compressed in the compressor (111), in a performance mode in a limited linear relationship having a set performance coefficient (Kp); and a step (S8 to S13) of setting the target high pressure and the inlet temperature in a limited linear relationship having a set efficiency coefficient (Ke) in an efficiency mode.

[0047] The control unit (10) operates a plurality of indoor units (120) in a cooling operation and a water heater (130) in a hot water operation (S1). Referring to FIG. 1, the control unit (10) switches the switching valve (114) so ​​that the refrigerant compressed in the compressor (111) flows to the outdoor heat exchanger (112), and controls the distributor (190) so that the refrigerant condensed in the outdoor unit (110) flows to the plurality of indoor units (120) and the refrigerant compressed in the outdoor unit (110) flows to the water heater (130). In addition, the control unit (10) adjusts the opening degree of a plurality of indoor expansion valves (122).

[0048] The flow of refrigerant during the cooling operation of the multiple indoor units (120) and the hot water operation of the water heater (130) is as described above with reference to FIG. 1.

[0049] When operating the cooling of multiple indoor units (120) and the hot water of the water heater (130), the control unit (10) collects the inlet temperature measured by the inlet temperature sensor (132), the outlet temperature measured by the outlet temperature sensor (133), and the discharge pressure measured by the high pressure sensor (115).

[0050] The control unit (10) determines whether it is a performance mode (S2). In a performance mode, if the increment between the discharge temperature and the inlet temperature (Δt = discharge temperature - inlet temperature) is a set performance increment (tp), that is, if Δt = tp, the control unit (10) determines that it is a performance mode.

[0051] In the case of performance mode, the control unit (10) sets the variable high pressure and the inlet temperature to a linear relationship in the performance mode (S3). The control unit (10) sets the variable high pressure and the inlet temperature to the following linear relationship in the performance mode, defined by the set constants: performance coefficient (Kp), reference temperature (Tb), and lower performance limit pressure (P1).

[0052] <Linear Relationship of Performance Modes>

[0053] Variable high pressure = Kp × (Inlet temperature - Tb) + P1

[0054] (Kp is the coefficient of performance, Tb is the reference temperature, P1 is the lower performance pressure limit)

[0055] The control unit (10) determines whether the variable high pressure calculated by the linear relationship of the performance mode exceeds the performance upper limit pressure (P2), which is a set constant (S4).

[0056] When the variable high pressure exceeds the performance upper limit pressure (P2), the control unit (10) sets the target pressure to the performance upper limit pressure (P2) (S5).

[0057] When the variable high pressure is not exceeded by the upper performance limit pressure (P2) (when the variable high pressure is less than or equal to the upper performance limit pressure (P2)), the control unit (10) determines whether the variable high pressure is less than the lower performance limit pressure (P1) (S6).

[0058] When the variable high pressure is less than the performance lower limit pressure (P1), the control unit (10) sets the target pressure to the performance lower limit pressure (P1) (S7).

[0059] When the variable high pressure is not less than the performance lower limit pressure (P1) (when the variable high pressure is greater than or equal to the performance lower limit pressure (P1)), the control unit (10) sets the target pressure to the variable high pressure (S15).

[0060] By steps S3 through S7 and S15, the limited forming relationship of the performance mode has a performance coefficient (Kp), a lower performance limit pressure (P1), and an upper performance limit pressure (P2). Referring to FIG. 4, the control unit (10) sets the target pressure to a range between the lower performance limit pressure (P1) and the upper performance limit pressure (P2), and sets it to be proportional to the inlet temperature between the lower performance limit pressure (P1) and the upper performance limit pressure (P2). That is, when the inlet temperature is below the reference temperature (Tb), the target pressure is the lower performance limit pressure (P1); when the inlet temperature exceeds the upper limit temperature (Ta), the target pressure is the upper performance limit pressure (P2); and when the inlet temperature is between the reference temperature (Tb) and the upper limit temperature (Ta), the target temperature is the linear relationship of the performance mode (= Kp × (inlet temperature - Tb) + P1).

[0061] If it is not in performance mode, the control unit (10) determines whether it is in efficiency mode (S8). In efficiency mode, if the increment between the discharge temperature and the inlet temperature (Δt = discharge temperature - inlet temperature) is the set efficiency increment (te), that is, if Δt = te, the control unit (10) determines that it is in efficiency mode.

[0062] The efficiency increment (te) is smaller than the performance increment (tp). (te < tp)

[0063] In the case of efficiency mode, the control unit (10) sets the variable high pressure and the inlet temperature to an efficiency mode linear relationship (S9). The control unit (10) sets the variable high pressure and the inlet temperature to the following efficiency mode linear relationship defined by the set constants: efficiency coefficient (Ke), reference temperature (Tb), and efficiency lower limit pressure (E1).

[0064] <Efficiency Mode Linear Relationship>

[0065] Variable high pressure = Ke × (Inlet temperature - Tb) + E1

[0066] (Ke is the efficiency factor, Tb is the reference temperature, E1 is the lower efficiency pressure limit)

[0067] The efficiency factor (Ke) is smaller than the performance factor (Kp). (Ke < Kp)

[0068] The control unit (10) determines whether the variable high pressure calculated by the efficiency mode linear relationship exceeds the efficiency upper limit pressure (E2), which is a set constant (S10).

[0069] When the variable high pressure exceeds the efficiency upper limit pressure (E2), the control unit (10) sets the target pressure to the efficiency upper limit pressure (E2) (S11).

[0070] When the variable high pressure is not exceeding the efficiency upper limit pressure (E2) (when the variable high pressure is less than or equal to the efficiency upper limit pressure (E2)), the control unit (10) determines whether the variable high pressure is less than the efficiency lower limit pressure (E1) (S12).

[0071] When the variable high pressure is less than the efficiency lower limit pressure (E1), the control unit (10) sets the target pressure to the efficiency lower limit pressure (E1) (S13).

[0072] When the variable high pressure is not less than the efficiency lower limit pressure (E1) (when the variable high pressure is greater than or equal to the efficiency lower limit pressure (E1)), the control unit (10) sets the target pressure to the variable high pressure (S15).

[0073] By steps S9 through S13 and S15, the limited forming relationship of the efficiency mode has an efficiency coefficient (Kp), an efficiency lower limit pressure (E1), and an efficiency upper limit pressure (E2). Referring to FIG. 4, the control unit (10) sets the target pressure to a range between the efficiency lower limit pressure (E1) and the efficiency upper limit pressure (E2), and sets it to be proportional to the inlet temperature between the efficiency upper limit pressure (E2) and the efficiency upper limit pressure (E2). That is, when the inlet temperature is below the reference temperature (Tb), the target pressure is the efficiency lower limit pressure (E1); when the inlet temperature is above the upper limit temperature (Ta), the target pressure is the efficiency upper limit pressure (E2); and when the inlet temperature is between the reference temperature (Tb) and the upper limit temperature (Ta), the target temperature is the efficiency mode linear relationship (= Ke × (inlet temperature - Tb) + E1).

[0074] The efficiency lower limit pressure (E1) is smaller than the performance lower limit pressure (P1), and the efficiency upper limit pressure (E2) is smaller than the performance upper limit pressure (P2). That is, the relationship is as follows.

[0075] Efficiency lower limit pressure (E1) < Performance lower limit pressure (P1) < Efficiency upper limit pressure (E2) < Performance upper limit pressure (P2)

[0076] When not in efficiency mode, the control unit (10) sets the target pressure to a fixed high pressure, which is a set constant (S14).

[0077] As described above, the control unit (10) controls the operating speed (frequency) of the compressor (111) so that the discharge pressure measured by the high-pressure sensor (115) becomes the target pressure set according to the inlet temperature. The control unit (10) sets the target pressure and the inlet temperature in a limited linear relationship.

[0078] The control unit (10) sets a coefficient of a limited linear relationship as a performance coefficient (Kp) or an efficiency coefficient (Ke) differently depending on the increment (Δt) of the discharge temperature and the inlet temperature. The control unit (10) sets the coefficient larger as the increment increases. In this embodiment, if the performance increment (tp) > efficiency increment (te), then the performance coefficient (Kp) > efficiency coefficient (Ke).

[0079] The control unit (10) sets the range of the target pressure differently depending on the increment (Δt) of the discharge temperature and the inlet temperature. The control unit (10) sets the range of the target pressure wider as the increment increases.

[0080] In this embodiment, if the performance increment (tp) > efficiency increment (te), then the performance lower limit pressure (P1) - performance upper limit pressure (P2) > efficiency lower limit pressure (E1) - efficiency upper limit pressure (E2).

[0081] The control unit (10) sets the lower limit of the target pressure higher as the increment (Δt) increases, and sets the upper limit of the target pressure higher as the increment (Δt) increases.

[0082] In this embodiment, if the performance increment (tp) > efficiency increment (te), then the performance lower limit pressure (P1) > efficiency lower limit pressure (E1) and the performance upper limit pressure (P2) > efficiency upper limit pressure (E2).

[0083] Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. Various modifications are possible by those skilled in the art without departing from the essence of the invention as claimed in the patent claims, and such modifications should not be understood individually from the technical spirit or perspective of the present invention.

Claims

1. A compressor that compresses refrigerant; An outdoor heat exchanger that condenses the refrigerant compressed in the above compressor; An indoor expansion valve that expands the refrigerant condensed in the above outdoor heat exchanger; An indoor heat exchanger that evaporates the refrigerant expanded in the above indoor expansion valve; A hot water heat exchanger that condenses the refrigerant compressed in the above compressor by heat exchange with water; A high-pressure sensor for measuring the discharge pressure, which is the pressure of the refrigerant compressed in the above compressor; An inlet temperature sensor for measuring the inlet temperature, which is the temperature of the water entering the hot water heat exchanger; An outlet temperature sensor for measuring the outlet temperature, which is the temperature of the water discharged from the hot water heat exchanger; and An air conditioner comprising a control unit that controls the compressor so that the discharge pressure becomes a target pressure set according to the inlet temperature.

2. In Paragraph 1, The above control unit is an air conditioner that sets the target pressure and the inlet temperature in a limited linear relationship.

3. In Paragraph 2, The above control unit is an air conditioner that sets the coefficient of the limited linear relationship differently according to the increment of the discharge temperature and the inlet temperature.

4. In Paragraph 3, The above control unit is an air conditioner that sets the coefficient larger as the above increment increases.

5. In Paragraph 1, The above control unit is an air conditioner that sets the range of the target pressure differently according to the increment of the discharge temperature and the inlet temperature.

6. In Paragraph 5, The above control unit is an air conditioner that sets the range of the target pressure wider as the above increment increases.

7. In Paragraph 5, The above control unit is an air conditioner that sets the lower limit of the target pressure higher as the above increment increases.

8. In Paragraph 5, The above control unit is an air conditioner that sets the upper limit of the target pressure higher as the above increment increases.

9. In Paragraph 1, The above control unit is, Determining whether it is a performance mode or an efficiency mode based on the increment of the above-mentioned discharge temperature and the above-mentioned inlet temperature, In the above performance mode, the above target pressure and the above inlet temperature are set to a limited linear relationship having a set performance coefficient, and In the above efficiency mode, the above target pressure and the above inlet temperature are set to a limited linear relationship having a set efficiency coefficient, and An air conditioner in which the above performance coefficient is greater than the above efficiency coefficient.

10. In Paragraph 9, The limited linear relationship of the above performance mode has a set lower performance pressure and a set upper performance pressure, The above-mentioned limited linear relationship of the efficiency mode has a set lower efficiency pressure and a set upper efficiency pressure, The above performance lower limit pressure is greater than the above efficiency lower limit pressure, and The above performance upper limit pressure is greater than the above performance upper limit pressure for an air conditioner.

11. A control method for an air conditioner comprising: a compressor for compressing a refrigerant; an outdoor heat exchanger for condensing the refrigerant compressed by the compressor; an indoor expansion valve for expanding the refrigerant condensed by the outdoor heat exchanger; an indoor heat exchanger for evaporating the refrigerant expanded by the indoor expansion valve; and a hot water heat exchanger for condensing the refrigerant compressed by the compressor by heat exchange with water. A step of determining whether it is a performance mode or an efficiency mode based on the increment of the discharge temperature, which is the temperature of the water discharged from the hot water heat exchanger, and the inlet temperature, which is the temperature of the water entering the hot water heat exchanger; In the case of the above performance mode, a step of setting the target pressure and the inlet temperature in a limited linear relationship having a set performance coefficient for the discharge pressure, which is the pressure of the refrigerant compressed in the compressor; and In the case of the above efficiency mode, the method includes the step of setting the target pressure and the inlet temperature into a limited linear relationship having a set efficiency coefficient, A control method for an air conditioner in which the above performance coefficient is greater than the above efficiency coefficient.

12. In Paragraph 11, The limited linear relationship of the above performance mode has a set lower performance pressure and a set upper performance pressure, The above-mentioned limited linear relationship of the efficiency mode has a set lower efficiency pressure and a set upper efficiency pressure, The above performance lower limit pressure is greater than the above efficiency lower limit pressure, and The above performance upper limit pressure is a control method for an air conditioner that is greater than the above performance upper limit pressure.

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