Patent Description:
Conventionally, a refrigeration cycle apparatus having a refrigerant amount determination function is disclosed. In Patent Document <NUM>, a state quantity of the refrigerant at a certain time and a state quantity of the refrigerant after a certain operation amount is applied to the state quantity are measured, and the amount of the refrigerant is determined according to whether a change corresponding to the operation amount is reflected in the state quantity (Patent Document <NUM> paragraph [<NUM>]).

[Patent Document <NUM>] <CIT>
Further related art may be found in <CIT> which describes a refrigerating and air-conditioning apparatus.

However, in Patent Document <NUM>, in order to accurately determine the amount of the refrigerant, estimated values of parameters of an ARX model must be identified. The present disclosure is intended to facilitate the determination of the amount of the refrigerant.

The object of the invention is solved by the refrigerant amount inference apparatus according to claim <NUM>, by the method performed by a computer that infers a refrigerant amount in an air conditioner according to claim <NUM> and a program causing a computer that infers a refrigerant amount in an air conditioner according to claim <NUM>.

In the following, an embodiment of the present disclosure will be described with reference to the drawings.

<FIG> is a diagram illustrating an overall configuration (a bypass example <NUM>) according to one embodiment of the present disclosure. An air conditioner <NUM> includes an outdoor unit <NUM> and an indoor unit <NUM>. As illustrated in <FIG>, a compressor <NUM>, a heat source side heat exchanger <NUM>, a supercooling heat exchanger <NUM>, a pressure reducing valve <NUM>, and a use side heat exchanger <NUM> are connected to a refrigerant mainstream circuit.

In the bypass example <NUM>, a supercooling bypass expansion valve <NUM> is provided in a bypass circuit connected from piping between the heat source side heat exchanger <NUM> and the supercooling heat exchanger <NUM> to piping on a suction side of the compressor <NUM>. The supercooling heat exchanger <NUM> is a heat exchanger that exchanges heat between refrigerant that has passed through the supercooling bypass expansion valve <NUM> provided in the bypass circuit connected to the piping on the suction side of the compressor <NUM> from a position between the heat source side heat exchanger <NUM> and the supercooling heat exchanger <NUM>, and refrigerant in the mainstream circuit.

In the outdoor unit <NUM>, the compressor <NUM> in which the number of rotations is variable or fixed, the heat source side heat exchanger <NUM>, and the supercooling heat exchanger <NUM> are connected to the piping. Additionally, the outdoor unit <NUM> includes an outdoor fan <NUM> that sends air to the heat source side heat exchanger <NUM>.

The outdoor unit <NUM> includes various sensors. Specifically, the outdoor unit <NUM> includes a temperature sensor <NUM> that detects the outdoor temperature, a temperature sensor <NUM> that detects the compressor inlet temperature, a temperature sensor <NUM> that detects the condenser inlet refrigerant temperature (the compressor outlet pressure), and a temperature sensor <NUM> that detects the condenser outlet refrigerant temperature. Additionally, the outdoor unit <NUM> includes a sensor <NUM> that detects the compressor inlet pressure and a sensor <NUM> that detects the condenser pressure.

In the indoor unit <NUM>, the use side heat exchanger <NUM> that exchanges heat with indoor air and the pressure reducing valve <NUM> for adjusting the refrigerant flow rate of the use side heat exchanger <NUM> are connected to the piping. Additionally, the indoor unit <NUM> includes an indoor fan <NUM> that sends air to the use side heat exchanger <NUM>.

The indoor unit <NUM> includes various sensors. Specifically, the indoor unit <NUM> includes a temperature sensor <NUM> that detects the indoor temperature, a temperature sensor <NUM> that detects the evaporator inlet refrigerant temperature, and a temperature sensor <NUM> that detects the evaporator outlet refrigerant temperature.

A control device <NUM> is a device that controls the air conditioner <NUM> and infers the refrigerant amount. Specifically, the control device <NUM> includes a controller <NUM> that controls the air conditioner <NUM>, a refrigerant amount inference unit <NUM> that infers the refrigerant amount, and a training data storage unit <NUM> that stores training data. The control device <NUM> may function as the controller <NUM> and the refrigerant amount inference unit <NUM> by executing a program. The refrigerant amount inference unit <NUM> and the training data storage unit <NUM> are also referred to as a refrigerant amount inference apparatus. The control device <NUM> will be described in detail below with reference to <FIG>.

Here, the control device <NUM> may be built into the air conditioner <NUM>. Alternatively, a portion of the control device <NUM> (e.g., the refrigerant amount inference unit <NUM> and the training data storage unit <NUM>) or an entirety of the control device <NUM> may be implemented on a device (e.g., a cloud server) that is separate from the air conditioner <NUM>.

<FIG> is a diagram illustrating the overall configuration (a bypass example <NUM>) according to one embodiment of the present disclosure. The air conditioner <NUM> includes the outdoor unit <NUM> and the indoor unit <NUM>. As illustrated in <FIG>, the compressor <NUM>, the heat source side heat exchanger <NUM>, the supercooling heat exchanger <NUM>, the pressure reducing valve <NUM>, and the use side heat exchanger <NUM> are connected to the refrigerant mainstream circuit. In the following, points that differ from the bypass example <NUM> will be mainly described.

In the bypass example <NUM>, the supercooling bypass expansion valve <NUM> is provided in a bypass circuit connected from piping between the pressure reducing valve <NUM> and the supercooling heat exchanger <NUM> to the piping on a suction side of the compressor <NUM>. The supercooling heat exchanger <NUM> is a heat exchanger that exchanges heat between refrigerant that passes through the supercooling bypass expansion valve <NUM> provided in a bypass circuit connected from a position between the pressure reducing valve <NUM> and the supercooling heat exchanger <NUM> to piping on the suction side of the compressor <NUM>, and the refrigerant in the mainstream circuit.

<FIG> is a hardware configuration diagram of the control device <NUM> according to one embodiment of the present disclosure. The control device <NUM> includes a central processing unit (CPU) <NUM>, a read only memory (ROM) <NUM>, and random access memory (RAM) <NUM>. The CPU <NUM>, the ROM <NUM>, and the RAM <NUM> form what is called a computer.

Additionally, the control device <NUM> includes an auxiliary storage device <NUM>, a display device <NUM>, an operation device <NUM>, and an interface (I/F) device <NUM>. The hardware components of the control device <NUM> are connected to one another via a bus <NUM>.

The CPU <NUM> is an arithmetic device that executes various programs installed in the auxiliary storage device <NUM>.

The ROM <NUM> is a non-volatile memory. The ROM <NUM> functions as a main storage device that stores various programs, data, and the like necessary for the CPU <NUM> to execute various programs installed in the auxiliary storage device <NUM>. Specifically, the ROM <NUM> functions as a main storage device that stores a boot program such as basic input/output system (BIOS), an extensible firmware interface (EFI), or the like.

The RAM <NUM> is a volatile memory such as a dynamic random access memory (DRAM) or a static random access memory (SRAM). The RAM <NUM> functions as a main storage device that provides a workspace in which various programs installed in the auxiliary storage device <NUM> are deployed when the various programs are executed by the CPU <NUM>.

The auxiliary storage device <NUM> is an auxiliary storage device that stores various programs and information used when the various programs are executed. The training data storage unit <NUM> is implemented in the auxiliary storage device <NUM>.

The display device <NUM> is a display device that displays an internal state of the control device <NUM> and the like.

The operation device <NUM> is an input device used by an administrator of the control device <NUM> to input various instructions to the control device <NUM>.

The I/F device <NUM> is a communication device that connects to various sensors and a network and communicates with another terminal.

<FIG> is a functional block diagram (a training phase) of the control device according to one embodiment of the present disclosure.

A supercooling degree acquiring unit <NUM> acquires, from the training data storage unit <NUM>, a state of the refrigerant (for example, the degree of supercooling acquired by the temperature sensor <NUM>) in the piping between the pressure reducing valve <NUM> of the air conditioner <NUM> and the supercooling heat exchanger <NUM> (hereinafter, referred to as first piping).

An expansion valve opening acquiring unit <NUM> acquires, from the training data storage unit <NUM>, an operation amount (for example, by the degree of the opening of the supercooling bypass expansion valve <NUM> related to the state of the refrigerant in the first piping.

The training unit <NUM> associates the state of the refrigerant in the first piping and the operation amount related to the state of the refrigerant in the first piping with the refrigerant amount (training data) acquired from the training data storage unit <NUM> to perform machine learning. The training unit <NUM> generates a refrigerant amount inference model <NUM> that can derive the refrigerant amount from the state of the refrigerant in the first piping and the operation amount related to the state of the refrigerant in the first piping by performing machine learning.

Here, the training data stored in the training data storage unit <NUM> is initial data at the time of installation of the air conditioner <NUM> or design data at the time of development of the air conditioner <NUM>. That is, the training data stored in the training data storage unit <NUM> is the refrigerant amount (for example, an appropriate amount of refrigerant), the state of the refrigerant in the first piping at that time, and the operation amount related to the state of the refrigerant in the first piping at that time.

The state of the refrigerant in the first piping is a value of the degree of supercooling detected by the temperature sensor <NUM> of the supercooling heat exchanger outlet temperature. The value of the degree of supercooling is a current value or both the current value and a pre-change value. The pre-change value is a value obtained before the operation related to the state of the refrigerant in the first piping (e.g., an adjustment of the opening of the supercooling bypass expansion valve <NUM>) is performed.

The operation amount related to the state of the refrigerant in the first piping is the operation amount including the degree of the opening of the supercooling bypass expansion valve <NUM>. The operation amount is a current value or both the current value and a pre-change value. The pre-change value is a value obtained before the operation (e.g., an adjustment of the opening of the supercooling bypass expansion valve <NUM>) related to the state of the refrigerant in the first piping is performed.

In addition to the above-described "the state of the refrigerant in the first piping and the operation amount related to the state of the refrigerant in the first piping", the training unit <NUM> may be configured to further input a condenser refrigerant state and the operation amount related to the condenser refrigerant state to perform training.

The condenser refrigerant state and the operation amount related to the condenser refrigerant state may include, for example, the condenser inlet refrigerant temperature acquired by the temperature sensor <NUM>, the condenser outlet refrigerant temperature acquired by the temperature sensor <NUM>, the condenser pressure acquired by the sensor <NUM>, the outside air temperature acquired by the temperature sensor <NUM>, the number of rotations of the fan <NUM>, and the circulation amount. Each value is a current value or both the current value and a pre-change value. The pre-change value is a value obtained before the operation related to the state of the refrigerant in the first piping (e.g., an adjustment of the opening of the supercooling bypass expansion valve <NUM>) is performed.

The circulation amount is calculated from the number of rotations of the compressor <NUM>, the compressor inlet/outlet pressure acquired by the sensors <NUM> and <NUM>, and the compressor inlet/outlet temperature acquired by the temperature sensors <NUM> and <NUM>.

In addition to the above-described "the state of the refrigerant in the first piping and the operation amount related to the state of the refrigerant in the first piping", the training unit <NUM> may be configured to further input an evaporator refrigerant state and the operation amount related to the evaporator refrigerant state to perform training.

The evaporator refrigerant state and the operation amount related to the evaporator refrigerant state may include, for example, the evaporator inlet refrigerant temperature acquired by the temperature sensor <NUM>, the evaporator outlet refrigerant temperature acquired by the temperature sensor <NUM>, the operation amount (e.g., the degree of the opening) of the pressure reducing valve <NUM>, the evaporator pressure, the room temperature acquired by the temperature sensor <NUM>, the indoor air flow volume, the indoor unit connection capacity, and the indoor unit connection model. Each value is a current value or both the current value and a pre-change value. The pre-change value is a value before the operation (e.g., an adjustment of the opening of the supercooling bypass expansion valve <NUM>) related to the state of the refrigerant in the first piping is performed.

Here, the evaporator pressure is calculated from the evaporator inlet refrigerant temperature.

As described, in addition to "the state of the refrigerant in the first piping and the operation amount related to the state of the refrigerant in the first piping", "the condenser refrigerant state and the operation amount related to the condenser refrigerant state or the evaporator refrigerant state and the operation amount related to the evaporator refrigerant state" can be used to improve the accuracy of the inference of the refrigerant amount.

<FIG> is a functional block diagram (an inference phase) of the control device <NUM> according to one embodiment of the present invention.

The supercooling degree acquiring unit <NUM> acquires, from the controller <NUM>, the state of the refrigerant in the piping (the first piping) between the pressure reducing valve <NUM> of the air conditioner <NUM> and the supercooling heat exchanger <NUM> (for example, the degree of supercooling acquired by the temperature sensor <NUM>).

The expansion valve opening acquiring unit <NUM> acquires, from the controller <NUM>, the operation amount (for example, the degree of the opening of the supercooling bypass expansion valve <NUM>) related to the state of the refrigerant in the first piping.

An inference unit <NUM> infers the refrigerant amount by inputting, into the refrigerant amount inference model <NUM> that has been trained by the training unit <NUM>, the state of the refrigerant in the first piping and the operation amount related to the state of the refrigerant in the first piping. The inference unit <NUM> notifies the controller <NUM> of the inferred refrigerant amount.

Here, the inference unit <NUM> may be configured to infer the refrigerant amount in question or may be configured to infer whether the refrigerant amount is appropriate (that is, whether there is an excess or an insufficient amount of refrigerant).

In the following, a case of inferring whether there is an excess or an insufficient amount of refrigerant will be described. The inference unit <NUM> may compare the inferred refrigerant amount with a predetermined threshold value (e.g., an appropriate amount of refrigerant determined for each model of the air conditioner <NUM>) to infer whether there is an excess or an insufficient amount of refrigerant. Alternatively, the inference unit <NUM> may assume that there is an excess amount of the refrigerant if the inferred refrigerant amount exceeds a predetermined upper limit value, and may assume that there is an insufficient amount of the refrigerant if the inferred refrigerant amount is less than a predetermined lower limit value.

<FIG> is a diagram for explaining the correspondence between the state of the refrigerant and the operation amount related to the state of the refrigerant; and the refrigerant amount, according to one embodiment of the present disclosure. As illustrated in <FIG>, the state of the refrigerant in the first piping (e.g., the degree of supercooling) and the operation amount related to the amount of the refrigerant in the first piping (e.g., the operation amount of the supercooling bypass expansion valve <NUM>); and the refrigerant amount are associated with one another. Therefore, for example, if the degree of supercooling changes with the same operation amount, it indicates that the refrigerant amount changes, and thus the refrigerant amount can be inferred.

<FIG> is a flowchart of a training process according to one embodiment of the present disclosure.

<FIG> is a flowchart of an inference process according to one embodiment of the present disclosure.

Claim 1:
A refrigerant amount inference apparatus that infers a refrigerant amount in an air conditioner (<NUM>)
in which a compressor (<NUM>), a heat source side heat exchanger (<NUM>), a supercooling heat exchanger (<NUM>), a pressure reducing valve (<NUM>), and a use side heat exchanger (<NUM>) are connected to piping, the supercooling heat exchanger being a heat exchanger that exchanges heat between refrigerant that passes through a supercooling bypass expansion valve (<NUM>) provided in a bypass circuit (<NUM>) and refrigerant in a mainstream circuit, the bypass circuit being connected to piping on a suction side of the compressor from a position between the heat source side heat exchanger and the supercooling heat exchanger or from a position between the pressure reducing valve and the supercooling heat exchanger,
the refrigerant amount inference apparatus comprising:
a training data storage unit(<NUM>) storing training data, and
a refrigerant amount inference unit (<NUM>) configured to acquire a state of refrigerant in first piping provided between the pressure reducing valve and the supercooling heat exchanger with a supercooling degree acquiring unit (<NUM>) and data from the training data storage unit, and an operation amount related to the state of the refrigerant in the first piping and including a degree of an opening of the supercooling bypass expansion valve (<NUM>) with an expansion valve opening acquiring unit (<NUM>)and data from the training data storage unit
wherein the refrigerant amount inference unit (<NUM>) performs machine learning to generate a refrigerant amount inference model (<NUM>) by using the state of the refrigerant in the first piping, the operation amount related to the state of the refrigerant in the first piping, and the refrigerant amount as the training data, so that the refrigerant amount inference model outputs the refrigerant amount in response to the state of the refrigerant in the first piping and the operation amount related to the state of the refrigerant in the first piping being input into the refrigerant amount inference model.