Multipart air-conditioning system and method for dividing a total energy consumption of a multipart air-conditioning system

Abstract

Various aspects relate to a multipart air-conditioning system and to a method for dividing a total energy consumption of a multipart air-conditioning system, wherein the method comprises: controlling at least one internal unit of the plurality of internal units according to a target temperature that has been set; measuring a first temperature at an outlet of at least one external unit and a second temperature at an inlet of the at least one external unit; determining a first pressure value, a second pressure value and a third pressure value; determining, for each of the plurality of internal units, a respective mass throughput and a respective enthalpy change of a coolant using the first pressure value, the second pressure value, the third pressure value, the first temperature and the second temperature; determining a respective power of each internal unit of the plurality of internal units using the determined mass throughput and the determined enthalpy change; determining, for each internal unit of the plurality of internal units, a proportion of the determined power in a total power which is a sum of the powers of all internal units; dividing the total energy consumption of the multipart air-conditioning system among the internal units according to the determined proportions.

Description

[0001] Multi-component air conditioning system and method for distributing total energy consumption of a multi-component air conditioning system

[0002] Technical area

[0003] Various embodiments generally relate to a multi-unit air conditioning system and a method for allocating a total energy consumption of a multi-unit air conditioning system.

[0004] background

[0005] A multi-unit air conditioning system, such as a system with variable refrigerant flow (VRF), can have at least one outdoor unit and several indoor units. The indoor units can be located in different units (e.g. rooms) of a building and these units can be assigned to different tenants (e.g. tenants of different apartments, tenants of different office spaces, etc.). In this case, it may be necessary for cost accounting (e.g. utility bills) to divide the total energy consumption of the multi-unit air conditioning system among the several indoor units depending on the energy consumption of the respective indoor unit. However, errors in sensors, assumptions regarding the refrigerant flow characteristics during the phase change (e.g.steam quality) and / or assumptions regarding the type of flow passing through the throttle valve can lead to falsifications and thus inaccurate information on the energy consumption of a particular indoor unit (and ultimately to incorrect cost accounting).

[0006] overview

[0007] The method and the multi-component air conditioning system with the features of independent claims 1 (first example) and 9 (fourteenth example) enable the performance (e.g., cooling capacity or heating capacity) of an indoor unit to be determined with increased accuracy, so that a more precise (e.g., exact) share of the total energy consumption of the multi-component air conditioning system can be determined for each indoor unit. A multi-component air conditioning system described herein may be a heating, ventilation, and air-conditioning (HVAC) system. The multi-component air conditioning system may comprise any type of air conditioning system having at least one outdoor unit and multiple indoor units, such as a variable refrigerant flow (VRF) system.

[0008] The term "control device" (also referred to as "control unit"), as used herein, can be understood as any type of logical implementation unit, which can, for example, include a circuit and / or a processor capable of executing software, firmware, or a combination thereof stored in a storage medium, and which can issue instructions, e.g., to one or more sensors, one or more indoor units, to one or more outdoor units, and receive data (e.g., acquired sensor data). The control device can, for example, be configured by program code (e.g., software) to control the operation of a system, in the present example, a multi-part air conditioning system. The control device (e.g., the control device 130) can include a computer and a memory that stores code and data, based on which the computer controls the air conditioning system (e.g., the air conditioning system 100) (e.g.,according to a control model). A "computer" can be understood as any type of logic-implementing entity, which can be hardware, software, firmware, or a combination thereof. Therefore, in one embodiment, a "computer" can be a hard-wired logic circuit or a programmable logic circuit, such as a programmable processor, for example, a microprocessor (e.g., a CISC (large instruction set processor) or a RISC (reduced instruction set processor)). A "computer" can comprise one or more processors. A "computer" can also be software implemented or executed by a processor, for example, any type of computer program, for example, a computer program using virtual machine code, such as Java.Any other manner of implementing the respective functions described in more detail below may be understood as a "computer" in accordance with an alternative embodiment. A "memory" may, for example, be used in the processing performed by the computer. A memory may be a volatile memory, for example a DRAM (dynamic random access memory), or a non-volatile memory, for example a PROM (programmable read-only memory), an EPROM (erasable PROM), an EEPROM (electrically erasable PROM), or a flash memory, such as a floating gate memory device, a charge trap memory device, an MRAM (magnetoresistive random access memory), or a PCRAM (phase change random access memory).

[0009] The multi-component air conditioning system may be a variable refrigerant flow system. The features described in this paragraph, in combination with the first example, constitute a second example.

[0010] Determining the first pressure value may include: determining the first pressure value using the first temperature value and a saturation pressure of the refrigerant; detecting the first pressure value using a first pressure sensor in the first section; and / or detecting a third temperature value using a temperature sensor arranged in the first section and determining the first pressure value using the third temperature value and the saturation pressure of the refrigerant. The features described in this paragraph in combination with the first example or the second example form a third example.Determining the second pressure value may include: detecting the second pressure value using a second pressure sensor in the second section; and / or detecting a fourth temperature value using a temperature sensor arranged in the second section and determining the second pressure value using the fourth temperature value and the saturation pressure of the refrigerant. The features described in this paragraph in combination with one or more of the first example to the third example form a fourth example.

[0011] Determining the third pressure value may include: determining the third pressure value using the second temperature value and the saturation pressure of the refrigerant; detecting the third pressure value using a third pressure sensor in the third section; and / or detecting a fifth temperature value using a temperature sensor arranged in the third section and determining the third pressure value using the fifth temperature value and the saturation pressure of the refrigerant. The features described in this paragraph in combination with one or more of the first example to the fourth example form a fifth example.

[0012] Determining the mass flow rate may comprise, for each indoor unit arranged in the first section, determining the mass flow rate of the indoor unit using the first pressure value, the second pressure value, and the technical data of the at least one first expansion valve. The features described in this paragraph in combination with one or more of the first example to the fifth example form a sixth example.

[0013] The technical data may include: a flow coefficient of the at least one first expansion valve; an opening cross-sectional area of ​​the at least one first expansion valve; and / or an expansion factor of the at least one first expansion valve. The features described in this paragraph in combination with the sixth example form a seventh example.

[0014] Determining the mass flow rate may comprise, for each indoor unit arranged in the third section, determining the mass flow rate of the indoor unit using the second pressure value, the third pressure value, and the technical data of the at least one second expansion valve. The features described in this paragraph in combination with one or more of the first example to the seventh example form an eighth example.

[0015] The technical data may include: a flow coefficient of the at least one second expansion valve; an opening cross-sectional area of ​​the at least one second expansion valve; and / or an expansion factor of the at least one second expansion valve. The features described in this paragraph in combination with the eighth example form a ninth example. Determining the enthalpy change of the refrigerant may include, for each indoor unit arranged in the first section: determining an inlet enthalpy as the sum of the vapor phase saturation enthalpy of the refrigerant at the first pressure value and a superheat enthalpy at the first pressure value; determining the enthalpy change by subtracting the liquid phase saturation enthalpy of the refrigerant at the second pressure value from the determined inlet enthalpy.The features described in this paragraph in combination with one or more of the first example through the ninth example constitute a tenth example.

[0016] The superheat enthalpy at the first pressure value can be determined by: determining a temperature difference between the first temperature value and the saturation temperature of the refrigerant at the first pressure value; determining the superheat enthalpy at the first pressure value as the product of the determined temperature difference and an average of the specific heat capacities of the refrigerant at the first temperature value and the saturation temperature at the first pressure value. The features described in this paragraph in combination with the tenth example form an eleventh example.

[0017] Determining the enthalpy change of the refrigerant may comprise, for each indoor unit arranged in the third section, determining an outlet enthalpy as the sum of the vapor-phase saturation enthalpy of the refrigerant at the third pressure value and a superheat enthalpy at the third pressure value; determining the enthalpy change by subtracting the liquid-phase saturation enthalpy of the refrigerant at the second pressure value from the determined outlet enthalpy. The features described in this paragraph in combination with one or more of the first example to the eleventh example form a twelfth example.

[0018] The superheat enthalpy at the third pressure value can be determined by: determining a temperature difference between the second temperature value and the saturation temperature of the refrigerant at the third pressure value; determining the superheat enthalpy at the third pressure value as the product of the determined temperature difference and an average of the specific heat capacities of the refrigerant at the second temperature value and the saturation temperature at the third pressure value. The features described in this paragraph, in combination with the twelfth example, form a thirteenth example.

[0019] A multi-part air conditioning system may comprise: a plurality of indoor units and at least one outdoor unit; at least one first expansion valve and at least one second expansion valve; a first temperature sensor (e.g. at an outlet of the at least one outdoor unit) in a section of a fluid-conducting connecting line between the at least one outdoor unit and the first expansion valve; a second temperature sensor (e.g.at an inlet of the at least one outdoor unit) in a section of a fluid-carrying connecting line between the second expansion valve and the at least one outdoor unit; a pressure sensor and / or a third temperature sensor in a section of a fluid-carrying connecting line between the at least one first expansion valve and the at least one second expansion valve; and a control device configured to carry out the method according to one of the first example to the thirteenth example. The multi-part air conditioning system having the features described in this paragraph constitutes a fourteenth example.

[0020] A memory (e.g., a computer program product, a non-volatile storage medium, and / or a non-volatile storage medium) can store program instructions which, when executed, perform the method according to one or more of the first example to the thirteenth example. The memory having the features described in this paragraph constitutes a fifteenth example.

[0021] Short description of the characters

[0022] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. They show:

[0023] - FIG. 1A, FIG. 1B and FIG. 2 show a multi-part air conditioning system according to various embodiments;

[0024] - FIG. 3 shows a pressure-enthalpy diagram of an exemplary cycle; and

[0025] - FIG. 4 and FIG. 5 each show a flowchart of a method for dividing a total energy consumption of a multi-part air conditioning system according to various embodiments.

[0026] Detailed description

[0027] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. It is to be understood that the features of the various exemplary embodiments described herein may be combined with one another unless specifically stated otherwise. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. It is to be understood that aspects described with respect to the multi-part air conditioning system apply analogously to the method described herein, and vice versa.It is understood that the term "and / or," as used herein, includes any combination of the associated elements. For various applications (e.g., for cost accounting), it may be necessary to determine the respective energy consumption of each indoor unit of a multi-unit air conditioning system. Various aspects relate to a multi-unit air conditioning system and a method capable of determining the energy consumption of each indoor unit of the multi-unit air conditioning system with increased accuracy.

[0028] FIG. 1 shows a multi-unit air conditioning system 100 according to various embodiments. The multi-unit air conditioning system 100 may be a variable refrigerant flow (VRF) system. The multi-unit air conditioning system 100 may include a plurality of indoor units 102(1<n<N). Here, “N” may be any integer greater than or equal to two (i.e., N>2). The multi-unit air conditioning system 100 may include at least one (i.e., exactly one or more than one) outdoor unit 104. Each indoor unit 102(n) of the plurality of indoor units 102(1<n<N) may be connected (e.g., fluidly connected) to the at least one outdoor unit 104 by one or more conduits (e.g., piping, such as copper piping). The multi-unit air conditioning system 100 may be a two-wire system or a three-wire system (also referred to as a heat recovery system).

[0029] Each indoor unit 102(n) of the plurality of indoor units 102(1 < n < N) can be configured to change one or more environmental parameters according to set parameters. For example, an indoor unit 102(n) can be configured to change an ambient temperature (e.g., measured by one or more temperature sensors) according to a set target temperature value (if a detected ambient temperature value differs from the set target temperature value). Each indoor unit 102(n) of the plurality of indoor units 102(n = 1 to N) can operate in either a first mode (also referred to as cooling mode) or a second mode (also referred to as heating mode). If the measured ambient temperature value is greater than the set target temperature value, the indoor unit 102(n) can operate in cooling mode to lower the ambient temperature (illustratively, the indoor unit can cool).If the measured ambient temperature is lower than the set target temperature, the indoor unit 102(n) can operate in heating mode to increase the ambient temperature (illustratively, the indoor unit can heat). An indoor unit 102(n) can be configured to operate exclusively in cooling mode, exclusively in heating mode, or in either cooling mode or heating mode depending on the set target temperature.

[0030] Depending on whether an indoor unit 102(n) is operating in cooling mode or heating mode, the refrigerant can be supplied to the indoor unit 102(n) either at a comparatively high pressure (in heating mode) or at a comparatively low pressure (in cooling mode). This can be seen, for example, from the refrigerant cycle carried out in the multi-part air conditioning system 100 (see, for example, FIG. 3), in which heat is absorbed by the refrigerant from the environment (QL) at the low pressure (p2 in FIG. 3) and released to the environment (QH) at the high pressure (pi in FIG. 3). It is understood that the refrigerant can be supplied from one component to another component of the multi-part air conditioning system 100 by means of corresponding lines (e.g., pipelines).The multi-part air conditioning system 100 can have a piping system by means of which the refrigerant can be provided to the plurality of indoor units 102(n=1 to N) via different lines depending on the respective mode (i.e., cooling mode or heating mode). For this purpose, the multi-part air conditioning system 100 can have a plurality of valves. According to various embodiments, the multi-part air conditioning system 100 can have a control device 130. The control device 130 can be configured to communicate with the plurality of indoor units 102(n=1 to N). The control device 130 can be configured to transmit control data (e.g., comprising the target temperature value) to a respective indoor unit 102(n) for controlling the indoor unit 102(n). The control device 130 can be configured to receive a measured ambient temperature value in the environment of a respective indoor unit 102(n) (e.g.,from a temperature sensor of the indoor unit and / or a temperature sensor arranged near the indoor unit). The communication described herein between the control device 130 and other components of the multi-part air conditioning system 100 (e.g., the plurality of indoor units, the at least one outdoor unit, the valves, etc.) can be wired and / or wireless (e.g., via Bluetooth and / or WLAN). The control device 130 can be configured to control the valves of the piping system depending on the respective mode (e.g., cooling mode or heating mode) of an indoor unit 102(n) such that the indoor unit 102(n) is provided with either the low-pressure refrigerant (in the cooling mode) or the high-pressure refrigerant (in the heating mode).

[0031] The multi-part air conditioning system 100 may comprise a first section 108 (also referred to as the first line section or high-pressure section), a second section 110 (also referred to as the second line section or medium-pressure section), and a third section 112 (also referred to as the third line section or low-pressure section). Each section of the multi-part air conditioning system 100 described herein may be a section of a fluid-carrying connecting line of the multi-part air conditioning system 100. The sections may be separated from one another by expansion valves. An expansion valve described herein may be configured to reduce a pressure of the refrigerant by expanding the refrigerant. The first section 108 may have a first refrigerant pressure (pi), the second section 110 may have a second refrigerant pressure (P2), and the third section may have a third refrigerant pressure (pQ).A value of the first pressure may be greater than a value of the second pressure, and a value of the second pressure may be greater than a value of the third pressure (i.e., ps< p2 < pi). References to "high," "medium," and "low" pressure used herein refer to the other pressures, respectively. The first pressure is also called high pressure because a value of the first pressure is greater than the values ​​of the second and third pressures. The third pressure is also called low pressure because a value of the third pressure is smaller than the values ​​of the second and third pressures. Consequently, the second pressure is also called medium pressure because a value of the third pressure lies between the values ​​of the first pressure and the third pressure.

[0032] The at least one outdoor unit 104 may include at least one compressor. The compressor may be configured to build up a pressure of a refrigerant used in the multi-part air conditioning system 100 (e.g., to pressurize the refrigerant or increase the pressure of the refrigerant). The refrigerant may be any refrigerant used in conventional multi-part air conditioning systems, such as R-410A refrigerant. The at least one outdoor unit 104 may include an outlet 104A and an inlet 104B. The outlet 104A may be fluidly connected to the first section 108. The inlet 104B may be fluidly connected to the third section 112. The at least one outdoor unit 104 may be configured to increase the pressure of the refrigerant using the at least one compressor.The at least one outdoor unit 104 may be configured to provide the refrigerant at elevated pressure (also referred to herein as high-pressure refrigerant) to the first section 108 of the multi-component air conditioning system 100 via the outlet 104A. The power consumption of the at least one compressor may represent at least a portion (e.g., all) of the energy consumption described herein (e.g., the total energy consumption).

[0033] Each indoor unit 102(n) can be assigned a respective expansion valve 106(n). If the indoor unit 102(n) is in the heating mode, the refrigerant can be provided to the indoor unit 102(n) directly via the first section 108. The indoor unit 102(n) in the heating mode can provide the refrigerant to the second section 110 via the associated expansion valve 106(n). Illustratively, the expansion valve 106(n) can reduce the pressure of the refrigerant from the high pressure to the medium pressure by expanding the refrigerant. If the indoor unit 102(n) is in the cooling mode, the refrigerant can be provided to the indoor unit 102(n) directly via the associated expansion valve 106(n), to which the refrigerant is provided via the second section 110. In the configuration shown in FIG. 1A and FIG.1B, a first indoor unit 102(n=1) of the plurality of indoor units 102(n=1 to N) may be in the heating mode, and a second indoor unit 102(n=2) and a third indoor unit 102(n=3) of the plurality of indoor units 102(n=1 to N) may be in the cooling mode.

[0034] Optionally, the multi-compartment air conditioning system 100 may include an additional expansion valve 114 disposed between the second section 110 and the third section 112. Optionally, the multi-compartment air conditioning system 100 may include a sub-cycle heat exchanger 116 disposed in the third section 112. Optionally, the multi-compartment air conditioning system 100 may include another additional expansion valve 120 disposed between the first section 108 and the second section 110.

[0035] FIG. 1B shows the multi-part air conditioning system 100, illustrating the first section 108 as the high-pressure region 122, the second section 110 as the medium-pressure region 124, and the third section 112 as the low-pressure region 126. The at least one outdoor unit 104 may include one or more temperature sensors coupled to the outlet 104A for sensing an outlet temperature of the refrigerant. The at least one outdoor unit 104 may include one or more temperature sensors coupled to the inlet 104B for sensing an inlet temperature of the refrigerant. Optionally, the multi-part air conditioning system 100 may include at least one first sensor 118(1) that may be configured to sense a pressure and / or a temperature of the refrigerant in the first section 108.Optionally, the multi-part air conditioning system 100 may include at least one third sensor 118(3), which may be configured to detect a pressure and / or a temperature of the refrigerant in the third section 112. The multi-part air conditioning system 100 may include at least one second sensor 118(2), which may be configured to detect a pressure and / or a temperature of the refrigerant in the second section 110. The at least one second sensor 118(2) may (in the present example) be arranged on a line between the first expansion valve 106(1) and the second expansion valve 106(2) and / or may be arranged on a line (also as a feedback line) to the additional expansion valve 114, which may be associated with the sub-cycle heat exchanger 116.

[0036] FIG. 2 shows an exemplary embodiment of the multi-part air conditioning system 100 with a plurality of pressure sensors (P) and a plurality of temperature sensors (T), wherein a fourth indoor unit 102(4) and a fifth indoor unit 102(5) can be designed as a plate heat exchanger.

[0037] FIG. 3 shows a pressure-enthalpy diagram of an exemplary refrigerant, specifically the relationship between the pressure, p, and the specific enthalpy, h, for the refrigerant. The diagram shows a liquid phase region 302 in which the refrigerant is in liquid phase, a vapor phase region 306 in which the refrigerant is in vapor form, and a two-phase region lying between the liquid phase region 302 and the vapor phase region 306 in which both the liquid phase and the vapor phase of the refrigerant are present. The transition between the liquid phase region 302 and the two-phase region 304 is defined by the boiling line 308 (in some aspects also referred to as a boiling curve). The transition between the two-phase region 304 and the vapor phase region 306 is defined by the dew line 310 (in some aspects also referred to as a dew curve).The pressure-enthalpy diagram of the refrigerant shows an example cycle, such as that used in a multi-component air conditioning system. Here, pi (phigh) represents the first (high) pressure, p2 the second (medium) pressure, and ps (pi) ow ) the third (low) pressure. In 300A, the enthalpy change of the refrigerant in an indoor unit 102(n) during heating (i.e., in the heating mode of the indoor unit) is highlighted (from 4 to 7). Illustratively, heat (QH) is released from the refrigerant to the environment (i.e., the environment is heated). In 300B, the enthalpy change of the refrigerant in an indoor unit 102(n) during cooling (i.e., in the cooling mode of the indoor unit) is highlighted (from 1 to 3). Illustratively, the refrigerant absorbs heat (QL) from the environment (i.e., the environment is cooled). Illustratively, the heating or cooling is provided by means of phase transitions of the refrigerant.

[0038] FIG. 4 shows a flowchart of a method 400 for allocating a total energy consumption 422 of a multi-component air conditioning system according to various embodiments. The method 400 is described below using the example of the multi-component air conditioning system 100. For example, the control device 130 may be configured to execute (e.g., perform) the method 400.

[0039] The method 400 may include determining and / or detecting a value of the first pressure, p1, as the first pressure value 404(1), a value of the second pressure, p2, as the second pressure value 404(2), and a value of the third pressure, ps, as the third pressure value 404(3). The first pressure value 404(1) may be determined based on the outlet temperature detected by the one or more temperature sensors arranged at the outlet 104A and a saturation pressure of the refrigerant. The at least one first sensor 118(1) may be a pressure sensor configured to detect the first pressure value 404(1). The at least one first sensor 118(1) may be a temperature sensor configured to detect a temperature value based on which (and based on the saturation pressure of the refrigerant) the first pressure value 404(1) can be determined. The at least one second sensor 118(2) may be a pressure sensor configured to detect the second pressure value 404(2).The at least one second sensor 118(2) can be a temperature sensor configured to detect a temperature value based on which (and based on the saturation pressure of the refrigerant) the second pressure value 404(2) can be determined. The third pressure value 404(3) can be determined based on the inlet temperature detected by the one or more temperature sensors arranged at the inlet 104B and the saturation pressure of the refrigerant. The at least one third sensor 118(3) can be a pressure sensor configured to detect the third pressure value 404(3). The at least one third sensor 118(3) can be a temperature sensor configured to detect a temperature value based on which (and based on the saturation pressure of the refrigerant) the third pressure value 404(3) can be determined.

[0040] The method 400 may include determining technical data 408 of one or more (e.g., each) expansion valves 106(n). The technical data 408 may be stored at least partially in memory as data 406. The technical data 408 may include, for each expansion valve 106(n), a discharge coefficient, an orifice area, and / or an expansion factor. The technical data 408 may optionally further include: a model type of the indoor unit 102(n), a model number of the indoor unit 102(n), a power rating of the indoor unit 102(n), temperature sensor data, a maximum rated opening value of the expansion valve 106(n), and / or a rated opening diameter of the expansion valve 106(n). The required data (e.g., sensor data or technical data) can be provided to the control device 130 by means of a communication protocol 402.

[0041] The flow coefficient, C or Cd, can either be set to a predefined value (e.g. according to the product data of the respective expansion valve 106(n)) or can be determined according to equation (1) and / or equation (2): c d = e1+e2EEv + O3EEV 2 where and 3 predefined constants, EEV is the opening value of the

[0042] expansion valve 106(n), D is the diameter of the expansion valve 106(n), ^in is the inlet pressure of the refrigerant and (J is the surface tension of the refrigerant.

[0043] The opening cross-sectional area, A, can be determined according to equation (3): where actual is the opening value of the expansion valve 106(n), ^^max is the maximum nominal opening value of the expansion valve 106(n), and d is the nominal opening diameter of the expansion valve 106(n)

[0044] The control device 130 can be configured to determine 410 whether the respective indoor unit 102(n) of the plurality of indoor units 102(n=1 to N) is in the heating mode (H) or the cooling mode (K) (e.g., based on the respectively detected ambient temperature and the target temperature value). The control device 130 can be configured to determine a respective mass flow rate 412K / 412H for each indoor unit 102(n) of the plurality of indoor units 102(n=1 to N). The mass flow rate 412K / 412H can be determined using the flow coefficient, C or Cd, and the opening cross-sectional area, A, according to equation (4):

[0045] > where Y is the expansion factor of the expansion valve 106(n), Pi is the density of the refrigerant upstream of the expansion valve 106(n), i is the pressure of the refrigerant upstream of the expansion valve 106(n), and p is the pressure of the refrigerant downstream of the expansion valve 106(n). Alternatively, the expansion factor, Y, can be omitted. The density, Pi, of the refrigerant can be determined from the temperature in the section upstream of the expansion valve 106(n) (i.e., the first section 108 for heating mode and the second section 110 for cooling mode). The mass flow rate 412K for cooling mode of an indoor unit 102(n) can thus be determined from the pressure difference between the second pressure value, p2, and the third pressure value, ps (i.e., Pi ~ Po = p2 - ps). The mass flow rate 412H for the heating mode of an indoor unit 102(n) can therefore be determined from the pressure difference between the first pressure value, pi, and the second pressure value, p2 (i.e., Pi ~ PQ = pi - P2).

[0046] The control device 130 can be configured to determine a respective enthalpy change 414K / 414H (e.g., a change in the specific enthalpy of the refrigerant) for each indoor unit 102(n) of the plurality of indoor units 102(n = 1 to N). The enthalpy change 414H can be determined in the heating mode of the respective indoor unit 102(n) according to equation (5):

[0047] The enthalpy change from the specific enthalpy tu to the specific enthalpy h? is highlighted in 300A. The specific enthalpy h? can correspond to the value of the specific enthalpy at which the second pressure value, p2, intersects the refrigerant's boiling curve 308 (8 in FIG. 3, also referred to as the liquid-phase saturation enthalpy at p2). The specific enthalpy tu can be determined according to equation (6): where tu is the specific enthalpy (also referred to as vapor-phase saturation enthalpy at pi) at which the first pressure value, pi, intersects the dew line 310 of the refrigerant (5 in FIG. 3), where T4 is the temperature in the first section 108 (e.g., detected as the outlet temperature and / or by means of the first sensor 108(1) embodied as a temperature sensor), where T4 is the saturation temperature of the refrigerant at the first pressure value, pi. The second summand can also be referred to as the superheat enthalpy at the first pressure value, pi. P av 9 Heating gives j en Average of specific heat capacities, c p , of the refrigerant at temperatures T4 and T5 and can be determined according to equation (7): (7). The enthalpy change 414K can be determined in the case of the cooling mode of the respective indoor unit 102(n) according to equation (8): h-cooi ~ ^3 ~ hi (8).

[0048] The enthalpy change from the specific enthalpy hi to the specific enthalpy hs is highlighted in 300B. The specific enthalpy hi can correspond to the specific enthalpy value at which the second pressure value, p2, intersects the refrigerant's boiling curve 308 (8 in FIG. 3). The specific enthalpy tu can be determined according to equation (9): where h2 is the specific enthalpy (also referred to as vapor-phase saturation enthalpy at ps) at which the third pressure value, ps, intersects the dew line 310 of the refrigerant (2 in FIG. 3), where T3 is the temperature in the second section 110 (e.g., detected by the second sensor 108(2) embodied as a temperature sensor), and where T2 is the saturation temperature of the refrigerant at the third pressure value, p3. The second summand can also be referred to as the superheat enthalpy at the third pressure value, p3. c p avg cooimg j enAverage of specific heat capacities, c p , of the refrigerant at temperatures T2 and T3 and can be determined according to equation (10):

[0049] The control device 130 can be configured to determine a respective power 416K / 416H of the indoor unit 102(n) for each of the plurality of indoor units 102(n = 1 to N) using the determined mass flow rate 412K / 412H and the determined enthalpy change 414K / 414H. The power 416K / 416H (QIDU) of a respective indoor unit 102(n) can be determined according to equation (11):

[0050] QIDU = ^IDU * h-iDu (11), where i / Du is the mass flow rate 412K / 412H determined for the indoor unit 102(n) and h-iDu is the enthalpy change 414K / 414H determined for the indoor unit 102(n).

[0051] The control device 130 can be configured to determine a proportion of the determined power, QIDU, to a total power for each indoor unit 102(n) of the plurality of indoor units 102(n=1 to N) (in 418). The total power (Qtotai) can be a sum of the powers of all indoor units of the plurality of indoor units 102(n=1 to N) (Qtotai =

[0052] QIDU) - The control device 130 can receive a value for a total energy consumption 422 of the at least one outdoor unit. For example, the at least one outdoor unit can have one or more electricity meters, and the total energy consumption 422 can be an electricity value detected by the one or more electricity meters. The control device 130 can be configured to determine a proportion, P Du (, for each indoor unit 102(n) of the plurality of indoor units 102(n = 1 to N). n , an the total energy consumption 422 Ptotad zudetermine according to the proportion determined in 418 (in 420), e.g. according to equation (12):

[0053] The total energy consumption can be seen as 422 ( P totai ) of the multi-unit air conditioning system 100 are distributed among the plurality of indoor units 102 (n = 1 to N).

[0054] According to various embodiments, total energy consumption 422 (P totai ) in a predefined time interval (e.g., every approximately 10 to approximately 300 seconds) according to method 400. Optionally, a user (e.g., tenant) assigned to an indoor unit 102(n) may be provided with information regarding the proportion, Pi DU(n) , provided (e.g., on a screen). Optionally, only the respective share of the indoor units can be determined (and stored in the memory) in the predefined time interval, and in another predefined time interval (e.g., daily, weekly, monthly, annually, etc.), the total energy consumption within the other predefined time interval can be divided based on all stored shares (e.g., for the annual utility bill).

[0055] According to various embodiments, an operating mode of an indoor unit can be classified (e.g., categorized) into the following categories: continuously operating, maintenance / servicing, off. For maintenance / servicing or off operating modes, energy consumption can be distributed evenly among the indoor units or according to method 400 (but limited to the power of the respective indoor unit between two activations of the maintenance / servicing operating mode). An exemplary distribution for the various operating modes is shown in the following table, where cooling model refers to path "K" and heating model refers to path "H" in method 400:

[0056] The method 400 described herein enables a more accurate calculation of the respective proportion compared to calculations based on psychometric enthalpy changes in the air, based on mass flow calculations using an expansion valve pulse value, based on a scaling of used and / or saved energy, or a division of the load into percentages or levels (e.g., from 1 to 5) using a difference between the target temperature and the ambient temperature, and using a rated power of an indoor unit. The method 400 uses the pressure values ​​in the three pressure ranges (the high pressure range, the medium pressure range, and the low pressure range) by direct measurement (using pressure sensors) or indirect measurement (using temperature sensors) in conjunction with the technical data of a respective associated expansion valve to calculate the mass flow rate.Method 400 requires neither an air temperature at an inlet or outlet nor an ambient temperature, which, for example, increases the accuracy of the determined proportions. Method 400 is further advantageous in that no additional hardware is required for data acquisition and / or data evaluation. FIG. 5 shows a flowchart of a method 500 for distributing total energy consumption of a multi-part air conditioning system according to various embodiments. Method 500 may include controlling at least one indoor unit of a plurality of indoor units of the multi-part air conditioning system according to a respectively set target temperature (in 502). Method 500 may include detecting a first temperature value of a temperature at an outlet of at least one outdoor unit of the multi-part air conditioning system (in 504).The method 500 may include detecting a second temperature value of a temperature at an inlet of the at least one outdoor unit (in 504). The method 500 may include determining a first (high) pressure value, a second (medium) pressure value, and a third (low) pressure value in different sections (of a respective fluid-carrying connecting line) of the multi-part air conditioning system (in 506). The first pressure value may represent a pressure in a first section between the outlet of the at least one outdoor unit and at least one first expansion valve. The second pressure value may represent a pressure in a second section between the at least one first expansion valve and at least one second expansion valve. The third pressure value may represent a pressure in a third section between the at least one second expansion valve and the inlet of the at least one outdoor unit.Method 500 may include determining, for each indoor unit of the plurality of indoor units (at 508), a respective mass flow rate and a respective enthalpy change of a refrigerant used in the multi-part air conditioning system. The mass flow rate and the enthalpy change may be determined depending on the mode (e.g., cooling mode or heating mode) of the indoor unit. The mass flow rate may be determined using the second pressure value in conjunction with the first pressure value or the third pressure value and using technical data of the first expansion valve or the second expansion valve. The enthalpy change may be determined using the first temperature value, the second temperature value, the first pressure value, the second pressure value, the third pressure value, and the pressure-enthalpy diagram of the refrigerant (see, for example, method 400 and associated equations).The method 500 may include determining a respective power for each indoor unit of the plurality of indoor units using the determined mass flow rate and the determined enthalpy change (in 510). The method 500 may include determining a respective proportion of the determined power to a total power for each indoor unit of the plurality of indoor units (in 512). The total power may be a sum of the powers of the plurality of indoor units. The method 500 may include dividing a total energy consumption of the multi-part air conditioning system (e.g., a power consumption of the at least one outdoor unit) among the plurality of indoor units according to the determined proportions (in 514).

Claims

Patent claims 1. A method (400) for dividing a total energy consumption (422) of a multi-part air conditioning system (100) among a plurality of indoor units (102) of the multi-part air conditioning system (100), the method (500) comprising: • Controlling at least one indoor unit of the plurality of indoor units (102) according to a set target temperature; • Detecting a first temperature value of a temperature at an outlet (104A) of at least one outdoor unit (104) of the multi-part air conditioning system (100) and a second temperature value of a temperature at an inlet (104B) of the at least one outdoor unit (104); • Determining a first pressure value which represents a pressure in a first section (108) of a fluid-carrying connecting line between the outlet (104A) of the at least one outdoor unit (104) and at least one first expansion valve (106(1)) of the multi-part air conditioning system (100); • Determining a second pressure value which represents a pressure in a second section (110) of a fluid-carrying connecting line between the at least one first expansion valve (106(1)) and at least one second expansion valve (106(2)) of the multi-part air conditioning system (100); • Determining a third pressure value which represents a pressure in a third section (112) of a fluid-carrying connecting line between the at least one second expansion valve (106(2)) and the inlet (104B) of the at least one outdoor unit (104); • for each indoor unit of the plurality of indoor units (102), determining a respective mass flow rate (412K, 412H) and a respective enthalpy change (414K, 414H) of a refrigerant used in the multi-part air conditioning system (100) using the first pressure value, the second pressure value, the third pressure value, the first temperature value, the second temperature value and technical data of the at least one first expansion valve (106(1)) and the at least one second expansion valve (106(2)); • Determining a respective power (416K, 416H) of each indoor unit of the plurality of indoor units (102) using the determined mass flow rate (412K, 412H) and the determined enthalpy change (414K, 414H); • for each indoor unit of the plurality of indoor units (102), determining a proportion (418) of the determined power to a total power, which is a sum of the powers of the plurality of indoor units (102); • Distributing (420) the total energy consumption (422) of the multi-part air conditioning system (100) among the plurality of indoor units (102) according to the determined proportions (418).

2. The method (400) according to claim 1, wherein determining the first pressure value comprises: • Determining the first pressure value using the first temperature value and a saturation pressure of the refrigerant; • Detecting the first pressure value by means of a first pressure sensor in the first section (108); and / or • Detecting a third temperature value by means of a temperature sensor arranged in the first section (108) and determining the first pressure value using the third temperature value and the saturation pressure of the refrigerant; and / or wherein determining the second pressure value comprises: • Detecting the second pressure value by means of a second pressure sensor in the second section (110); and / or • Detecting a fourth temperature value by means of a temperature sensor arranged in the second section (110) and determining the second pressure value using the fourth temperature value and the saturation pressure of the refrigerant; and / or wherein determining the third pressure value comprises: • Determining the third pressure value using the second temperature value and the saturation pressure of the refrigerant; • detecting the third pressure value by means of a third pressure sensor in the third section (112); and / or • Detecting a fifth temperature value by means of a temperature sensor arranged in the third section (112) and determining the third pressure value using the fifth temperature value and the saturation pressure of the refrigerant.

3. The method (400) according to claim 1 or 2, wherein determining the mass flow rate (412K, 412H) for each indoor unit arranged in the first section (108) comprises: • Determining the mass flow rate (412H) of the indoor unit using the first pressure value, the second pressure value and the technical data of the at least one first expansion valve (106(1)); wherein the technical data optionally comprises: • a flow coefficient of the at least one first expansion valve (106(1)); • an opening cross-sectional area of ​​the at least one first expansion valve (106(1)); and / or • an expansion factor of the at least one first expansion valve (106(1)).

4. The method (400) according to any one of claims 1 to 3, wherein determining the mass flow rate (412K, 412H) for each indoor unit arranged in the third section (112) comprises: • Determining the mass flow rate (412K) of the indoor unit using the second pressure value, the third pressure value and the technical data of the at least one second expansion valve (106(2)); wherein the technical data optionally comprises: • a flow coefficient of the at least one second expansion valve (106(2)); • an opening cross-sectional area of ​​the at least one second expansion valve (106(2)); and / or • an expansion factor of the at least one second expansion valve (106(2)).

5. The method (400) according to any one of claims 1 to 4, wherein determining the enthalpy change (414K, 414H) of the refrigerant for each indoor unit arranged in the first section (108) comprises: • Determining an inlet enthalpy as the sum of the vapor phase saturation enthalpy of the refrigerant at the first pressure value and a superheat enthalpy at the first pressure value; • Determining the enthalpy change (414H) by subtracting the liquid phase saturation enthalpy of the refrigerant at the second pressure value from the determined inlet enthalpy.

6. The method (400) according to claim 5, wherein the superheat enthalpy at the first pressure value is determined by means of: • Determining a temperature difference between the first temperature value and the saturation temperature of the refrigerant at the first pressure value; • Determining the superheat enthalpy at the first pressure value as the product of the determined temperature difference and an average of the specific heat capacities of the refrigerant at the first temperature value and the saturation temperature at the first pressure value.

7. The method (400) according to any one of claims 1 to 6, wherein determining the enthalpy change (414K, 414H) of the refrigerant for each indoor unit arranged in the third section (112) comprises: • Determining an outlet enthalpy as the sum of the vapor phase saturation enthalpy of the refrigerant at the third pressure value and a superheat enthalpy at the third pressure value; • Determining the enthalpy change (414K) by subtracting the liquid-phase saturation enthalpy of the refrigerant at the second pressure value from the determined outlet enthalpy. The method (400) according to claim 7, wherein the superheat enthalpy at the third pressure value is determined by: • Determining a temperature difference between the second temperature value and the saturation temperature of the refrigerant at the third pressure value; • Determining the superheat enthalpy at the third pressure value as the product of the determined temperature difference and an average of the specific heat capacities of the refrigerant at the second temperature value and the saturation temperature at the third pressure value. A multi-part air conditioning system (100), comprising: • several indoor units (102) and at least one outdoor unit (104); • at least one first expansion valve (106(1)) and at least one second expansion valve (106(2)); • a first temperature sensor (118(1)) in a section (108) of a fluid-carrying connecting line between the at least one outdoor unit (104) and the first expansion valve (106(1)); • a second temperature sensor (118(3)) in a section (112) of a fluid-carrying connecting line between the second expansion valve (106(1)) and the at least one outdoor unit (104); • a pressure sensor (118(2)) and / or a third temperature sensor (118(2)) in a section (110) of a fluid-carrying connecting line between the at least one first expansion valve (106(1)) and the at least one second expansion valve (106(2)); • a control device (130) configured to carry out the method (400) according to any one of claims 1 to 8. The multi-component air conditioning system (100) according to claim 9, wherein the air conditioning system (100) is a variable refrigerant flow system.

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