Patent Application
20250123036
The present disclosure relates to a heat pump system capable of supplying hot water through heat exchange and a method of controlling the heat pump system.
In an air-to-water heat pump system, heat is exchanged during heating operations. The outdoor unit exchanges heat with the air through the evaporator, while the indoor unit adjusts the temperature of indoor air using the condenser. Additionally, heat is exchanged between water and a refrigerant through the internal heat exchanger of either the indoor or outdoor unit, allowing water to be supplied at the desired temperature according to the user's settings.
Air-to-water heat pump systems are classified based on a heating operation. An air-to-water heat pump system that has both an evaporator and a condenser in an outdoor unit is classified as a Mono system. An air-to-water heat pump system that has an evaporator in an outdoor unit and a condenser in an indoor unit is classified as a Split system. Water supplied by air-to-water heat pump systems is commonly used for floor heating, radiators, hot-water supply, and fan coil units.
During the heater operation of an air-to-water heat pump system, the temperature of water is controlled to meet a user's desired temperature through the evaporator, condenser, compressor, and an expansion valve of the air conditioner system.
Changing a high-pressure refrigerant into a low-pressure refrigerant through a phase change of the refrigerant is accomplished through a throttling process, and this process is controlled through an electronic expansion valve (EEV).
Conventionally, a target degree of superheat is set according to the pressure and temperature of a refrigerant entering the compressor, and the expansion valve is controlled such that a current degree of superheat reaches the target degree of superheat.
However, because outlet temperature conditions and outside temperature conditions applied to the air-to-water heat pump system vary, the density and volume of the refrigerant vary. As a result, the pressure may increase excessively or a heating capacity may become insufficient, which may reduce the operation reliability of the compressor and the heating capacity. In addition, unlike the existing R32 or R410A refrigerant, the R290 refrigerant has an outlet temperature range of 15° C. to 75° C. and an outside temperature range of −25° C. to 43° C. that are wider than those of other refrigerants, and also, the outlet temperature of the R290 refrigerant has high maximum temperature, which further reduces the operation reliability of the compressor and the heating capacity.
An aspect of the disclosure provides a heat pump system configured to control an expansion valve based on an optimized target discharge temperature during a heating operation according to an air-to-water heat pump method, and a method of controlling the heat pump system. Accordingly, the heat pump system is capable of raising operation reliability in various outlet temperature conditions and outside temperature conditions, and performing a heating operation with optimal efficiency.
According to an aspect of the present disclosure, a heat pump system may include; a water-refrigerant heat exchanger connected to a compressor; an expansion valve connected to the water-refrigerant heat exchanger; an outdoor heat exchanger connected to the expansion valve; an outlet temperature sensor configured to detect an outlet temperature of the water-refrigerant heat exchanger; an outside temperature sensor configured to detect an outside temperature; a discharge pressure sensor configured to detect pressure of a refrigerant discharged from the compressor; a suction pressure sensor configured to detect pressure of a refrigerant that enters the compressor; and at least one processor configured to obtain, during a heating operation, a first target discharge temperature of the compressor based on an output value from the outlet temperature sensor and an output value from the outside temperature sensor, obtain a second target discharge temperature of the compressor based on an output value from the discharge pressure sensor and an output value from the suction pressure sensor, set any one of the first target discharge temperature or the second target discharge temperature to a final target discharge temperature, and control the expansion valve based on the final target discharge temperature.
According to an aspect of the present disclosure, a method of controlling a heat pump system may include: obtaining, during a heating operation, a first target discharge temperature of a compressor based on an outlet temperature of a water-refrigerant heat exchanger and an outside temperature; obtaining a second target discharge temperature of the compressor based on pressure of a refrigerant discharged from the compressor and pressure of a refrigerant that enters the compressor; setting any one of the first target discharge temperature or the second target discharge temperature to a final target discharge temperature; and controlling an expansion valve based on the final target discharge temperature.
It should be appreciated that various embodiments of the present document and the terms used therein are not intended to limit the technological features set forth herein to particular embodiments and include various changes, equivalents, or replacements for the corresponding embodiments.
With regard to the description of the drawings, similar reference numerals may be used to refer to similar or related components.
Singular forms of nouns corresponding to items may include one or more of the items, unless the relevant context clearly indicates otherwise.
As used herein, each of such phrases as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C,” may include any one of, or all possible combinations of the items enumerated together in a corresponding one of the phrases.
The term “and/or” includes any and all combinations of one or more of a plurality of associated listed components.
As used herein, such terms as “1st” or “2nd” or “first” or “second” may be used to simply distinguish a corresponding component from another, and does not limit the components in another aspect (for example, importance or order).
It is to be understood that if a certain component (for example, a first component) is referred to, with or without the term “operatively” or “communicatively”, as “coupled with,” “coupled to,” “connected with,” or “connected to” another component (for example, a second component), it means that the component may be coupled with the other component directly (for example, by wire), wirelessly, or via a third element.
It is to be understood that the terms such as “including” or “having,” etc., are intended to indicate the existence of the features, numbers, steps, operations, components, parts, or combinations thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other features, numbers, steps, operations, components, parts, or combinations thereof may exist or may be added.
It will be understood that when a certain component is referred to as being “connected to”, “coupled to”, “supported by” or “in contact with” another component, it can be directly or indirectly connected to, coupled to, supported by, or in contact with the other component. When a component is indirectly connected to, coupled to, supported by, or in contact with another component, it may be connected to, coupled to, supported by, or in contact with the other component through a third component.
It will also be understood that when a certain component is referred to as being “on” or “over” another component, it can be directly on the other component or intervening components may also be present.
A heat pump system according to various embodiments will be described in detail with reference to the accompanying drawings.
Referring to
The heat pump system 1 may include a compressor 10, a water-refrigerant heat exchanger 20, a receiver 30, an expansion valve 40, an outdoor heat exchanger 50, and a flow path switching valve 60.
The compressor 10 may compress a low-temperature and low-pressure refrigerant received through an inlet 11 to form a high-temperature and high-pressure refrigerant, and then discharge the high-temperature and high-pressure refrigerant through an outlet 12.
The compressor 10 may be an inverter compressor of which a compression capacity changes depending on an input frequency. The compressor 10 may be a combination of a plurality of constant-speed compressors having a constant compression capacity.
The inlet 11 and outlet 12 of the compressor 10 may be connected to the flow path switching valve 60.
The flow path switching valve 60 may be a four-way valve. The flow path switching valve 60 may switch a flow of a refrigerant discharged from the compressor 10 according to a driving mode (cooling or heating) to form a refrigerant flow path required for driving of the corresponding mode.
The flow path switching valve 60 may include a first port 61 connected to the outlet 12 of the compressor 10, a second port 62 connected to the outdoor heat exchanger 50, a third port 63 connected to the water-refrigerant heat exchanger 20, and a fourth port 64 connected to the inlet 11 of the compressor 10.
The outdoor heat exchanger 50 may operate as a condenser in a cooling mode and as an evaporator in a heating mode.
The expansion valve 40 may be connected to one side of the outdoor heat exchanger 50.
In the outdoor heat exchanger 50, an outdoor fan may be installed to raise heat-exchange efficiency between a refrigerant and outside air.
The expansion valve 40 may be provided between the outdoor heat exchanger 50 and the water-refrigerant heat exchanger 20.
The expansion valve 40 may include an electronic expansion valve. The expansion valve 40 may decompress and expand a refrigerant, adjust a flow rate of the refrigerant, and block a flow of the refrigerant as necessary. The expansion valve 40 may be replaced with an expander having another structure capable of performing the functions.
The receiver 30 may be provided between the expansion valve 40 and the water-refrigerant heat exchanger 20.
The receiver 30 may temporarily store a refrigerant, separate an uncondensed refrigerant or a non-condensable gas contained in the refrigerant from the refrigerant, and send the refrigerant in a liquid state to the expansion valve 40.
In the water-refrigerant heat exchanger 20, a plurality of heat exchange plates through which a refrigerant passes and a plurality of heat exchange plates through which water received from a water supply tank passes may be installed alternately, and cold water/hot water may be generated through heat exchange between the heat exchange plates through which a refrigerant passes and the heat exchange plates through which water passes.
A refrigerant compressed in the compressor 10 may be transferred to the water-refrigerant heat exchanger 20.
Cold water/hot water generated in the water-refrigerant heat exchanger 20 may be provided to the water supply tank, a fan coil unit, a floor cooling/heating apparatus, etc. to be used for cold water/hot water supply and cooling/heating.
In the disclosure, a refrigerant cycle in a heating mode will be mainly described in which hot water is supplied through heat exchange between a refrigerant and water.
Referring to
A refrigerant discharged from the compressor 10 may pass through the flow path switching valve 60 and flow to the water-refrigerant heat exchanger 20, as indicated by arrows.
The refrigerant entered the water-refrigerant heat exchanger 20 may pass through the receiver 30 and the expansion valve 40 and flow to the outdoor heat exchanger 50.
The refrigerant passed through the outdoor heat exchanger 50 may again pass through the flow path switching valve 60 and enter the compressor 10.
Accordingly, the heat pump system 1 may configure a refrigerant cycle in which a refrigerant circulates in the order of compressor 10→flow path switching valve 60→water-refrigerant heat exchanger 20→receiver 30→expansion valve 40→outdoor heat exchanger 50→flow path switching valve 60→compressor 10 to perform a heating operation.
So far, a basic configuration of the heat pump system 1 and a flow of a refrigerant have been described.
Hereinafter, a process of setting optimal target discharge temperature based on the flow of a refrigerant and controlling the expansion valve 40 based on the optimal target discharge temperature will be described in detail.
Referring to
The outlet temperature sensor 110, the outside temperature sensor 120, the high-pressure sensor 130, the low-pressure sensor 140, and the discharge temperature sensor 150 may be electrically connected to the controller 100.
The outlet temperature sensor 110 may detect temperature of water heat-exchanged with a refrigerant in the water-refrigerant heat exchanger 20.
The outside temperature sensor 120 may detect an outside temperature.
The high-pressure sensor 130 may detect pressure of a refrigerant discharged from the compressor 10.
The low-pressure sensor 140 may detect pressure of a refrigerant that enters the compressor 10.
The discharge temperature sensor 150 may detect temperature of a refrigerant discharged from the compressor 10.
Referring to
The outside temperature sensor 120 may be positioned around or adjacent to the outdoor heat exchanger 50 to detect an outside temperature.
The high-pressure sensor 130 which can be implemented as a discharge pressure sensor 130 may be positioned around a discharge side of the compressor 10.
The high-pressure sensor 130 may detect pressure of a high-temperature and high-pressure refrigerant discharged from the compressor 10.
The low-pressure sensor 140 which is a suction pressure sensor may be positioned around the inlet 11 of the compressor 10.
The low-pressure sensor 140 may detect pressure of a low-temperature and low-pressure refrigerant that enters the compressor 10.
The low-pressure sensor 140 may detect pressure of a low-pressure refrigerant passed through the outdoor heat exchanger 50 before the refrigerant is compressed in the compressor 10.
The discharge temperature sensor 150 may be positioned around the outlet 12 of the compressor 10.
The discharge temperature sensor 150 may detect temperature of a high-temperature and high-pressure refrigerant discharged from the compressor 10.
Various information detected by the plurality of sensors may be used in a control process by the controller 100, and this will be described in detail, below.
Referring again to
The memory 102 may include one, two, or more memory chips or one, two, or more memory blocks. Also, the processor 101 and the memory 102 may be implemented as a single chip.
The controller 100 may obtain, during a heating operation, a first target discharge temperature based on output values from the outlet temperature sensor 110 and the outside temperature sensor 120.
According to an embodiment, the controller 100 may input outlet temperature and outside temperature to a first correlation function to obtain optimal discharge temperature in a normal heating cycle.
According to various embodiments, the controller 100 may obtain a high-pressure saturation temperature value according to an output value from the outlet temperature sensor 110, and obtain a high-pressure value according to the high-pressure saturation temperature value. At this time, the controller 100 may set a value obtained by adding a first value to the output value from the outlet temperature sensor 110, to the high-pressure saturation temperature value.
The controller 100 may obtain a low-pressure saturation temperature value according to an output value from the outside temperature sensor 120, and obtain a low-pressure value according to the low-pressure saturation temperature value. At this time, the controller 100 may set a value obtained by subtracting a second value from the output value from the outside temperature sensor 120, to the low-pressure saturation temperature value.
The controller 100 may obtain a discharge temperature corresponding to the high-pressure value and the low-pressure value.
The controller 100 may set the discharge temperature based on the high-pressure value and the low-pressure value to a first target discharge temperature.
The controller 100 may obtain a second target discharge temperature based on output values from the high-pressure sensor 130 and the low-pressure sensor 140.
The controller 100 may set a discharge temperature corresponding to the output value from the high-pressure sensor 130, and may set the output value from the low-pressure sensor 140 to a second target discharge temperature. At this time, the controller 100 may obtain the discharge temperature by inputting a high-pressure value detected by the high-pressure sensor 130 and a low-pressure value detected by the low-pressure sensor 140 to a second correlation function.
A refrigerant used in the heat pump system 1 according to an embodiment may be a R290 refrigerant. By applying unique properties of the R290 refrigerant and compressor operation efficiency characteristic to the first correlation function and the second correlation function when the first target discharge temperature and the second target discharge temperature are obtained, a first target discharge temperature and a second target discharge temperature to which characteristics of the R290 refrigerant have been reflected may be set. The unique properties of the R290 refrigerant may include pressure, saturation temperature, entropy, enthalpy, temperature, humidity, etc.
The controller 100 may correct the second target discharge temperature based on an operation frequency of the compressor 10 and/or outside temperature.
The controller 100 may correct the second target discharge temperature such that as the operation frequency of the compressor 10 increases, the second target discharge temperature increases. The controller 100 may correct the second target discharge temperature such that as the operation frequency of the compressor 10 decreases, the second target discharge temperature decreases.
Also, the controller 100 may correct the second target discharge temperature such that as outside temperature increases, the second target discharge temperature increases. The controller 100 may correct the second target discharge temperature such that as outside temperature decreases, the second target discharge temperature decreases.
The controller 100 may set any one of the first target discharge temperature or the second target discharge temperature to the final target discharge temperature.
According to an embodiment, the controller 100 may set a greater one of the first target discharge temperature and the second target discharge temperature to the final target discharge temperature.
According to various embodiments, the controller 100 may set, during a first section of a heating operation, the first target discharge temperature to the final target discharge temperature.
According to various embodiments, the controller 100 may set, during a second section of a heating operation, the second target discharge temperature to the final target discharge temperature.
The controller 100 may control the expansion valve 40 based on the final target discharge temperature. The controller 100 may control the expansion valve 40 based on a difference between the final target discharge temperature and discharge temperature detected by the discharge temperature sensor 150.
Referring to
The controller 100 may detect, during a heating operation, temperature of water heat-exchanged with a refrigerant in the water-refrigerant heat exchanger 20 through the outlet temperature sensor 110 (200). The controller 100 may detect temperature of water heat-exchanged with a refrigerant in the water-refrigerant heat exchanger 20 and then discharged from the water-refrigerant heat exchanger 20. For example, in the case in which a R290 refrigerant is used for a heating operation of the air-to-water heat pump system 1, an outlet temperature range of the water-refrigerant heat exchanger 20 may be between 15° C. and 75° C.
In addition, the controller 100 may detect an outside temperature through the outside temperature sensor 120 (202). For example, in the case in which a R290 refrigerant is used for a heating operation of the air-to-water heat pump system 1, an outside temperature range may be between −25° C. and 43° C.
The controller 100 may obtain a first target discharge temperature based on the outlet temperature and the outside temperature (204).
According to an embodiment, the controller 100 may obtain the first target discharge temperature by inputting the outlet temperature and the outside temperature to a first correlation function. The first correlation function may be a program mapped to receive outlet temperature and outside temperature as input variables and output optimal discharge temperature capable of forming a normal heating cycle under the received outlet temperature and outside temperature. Also, the first correlation function may have been mapped to output optimal discharge temperature that forms a normal heating cycle with a used refrigerant type.
According to various embodiments, the controller 100 may estimate high pressure corresponding to high-pressure saturation temperature according to outlet temperature, estimate low pressure corresponding to low-pressure saturation temperature according to outside temperature, and then obtain a first target discharge temperature according to the high pressure and low pressure. For example, the controller 100 may select optimal discharge temperature according to the high pressure and low pressure by applying, based on a degree of induction superheat of, for example, 2° C. of the compressor 10, isentropic efficiency (for example, 90% at a compression ratio of 2 or 80% at a compression rate of 10) according to a compression ratio of the compressor 10.
Referring to
In a normal heating cycle, high-pressure saturation temperature may be higher than outlet temperature by a first value (for example, 1° C.).
Accordingly, the controller 100 may set a value obtained by adding the first value to the outlet temperature to the high-pressure saturation temperature. For example, the high-pressure saturation temperature may be set to outlet temperature +1° C.
The controller 100 may obtain high pressure corresponding to the high-pressure saturation temperature (302).
The controller 100 may obtain low-temperature saturation temperature according to the outside temperature (304).
In a normal heating cycle, low-pressure saturation temperature may be lower than outside temperature by a second value (for example, 1° C.).
Accordingly, the controller 100 may set a value obtained by subtracting the second value from the outside temperature to the low-pressure saturation temperature. For example, the controller 100 may set the low-pressure saturation temperature to outside temperature −1° C.
The controller 100 may obtain low pressure corresponding to the low-pressure saturation temperature (306).
The controller 100 may obtain discharge temperature corresponding to the high pressure and low pressure (308).
The controller 100 may obtain optimal discharge temperature capable of forming a normal heating cycle under the obtained high pressure and low pressure. For example, the controller 100 may obtain discharge temperature corresponding to the high pressure and low pressure by using a P-H diagram.
The controller 100 may set the discharge temperature corresponding to the high pressure and low pressure to a first target discharge temperature (310).
Referring again to
The controller 100 may detect pressure of a low-temperature and low-pressure refrigerant that enters the compressor 10 through the low-pressure sensor 140 (208).
The controller 100 may obtain a second target discharge temperature based on the pressure of the high-temperature and high-pressure refrigerant discharged from the compressor 10 and the pressure of the low-temperature and low-pressure refrigerant that enters the compressor 10 (210).
According to an embodiment, the controller 100 may obtain the second target discharge temperature by inputting the pressure of the high-temperature and high-pressure refrigerant discharged from the compressor 10 and the pressure of the low-temperature and low-pressure refrigerant that enters the compressor 10 to a second correlation function. The second correlation function may be a program mapped to receive an output value (high pressure) from the high-pressure sensor 130 and an output value (low pressure) from the low-pressure sensor 140 as input variables and output optimal discharge temperature capable of forming a normal heating cycle under the received high pressure and low pressure. Also, the second correlation function may have been mapped to output optimal discharge temperature that forms a normal heating cycle with a used refrigerant type.
According to various embodiments, the controller 100 may obtain a second target discharge temperature corresponding to an output value (high pressure) from the high-pressure sensor 130 and an output value (low pressure) from the low-pressure sensor 140. For example, the controller 100 may select optimal discharge temperature according to the high pressure and low pressure by applying, based on a degree of induction superheat of, for example, 2° C. of the compressor 10, isentropic efficiency according to a compression ratio of the compressor 10.
Referring to
The controller 100 may correct the second target discharge temperature such that as an operation frequency of the compressor 10 increases, the second target discharge temperature increases. Also, the controller 100 may correct the second target discharge temperature such that as an operation frequency of the compressor 10 decreases, the second target discharge temperature decreases.
As an operation frequency of the compressor 10 increases, friction loss may increase. By correcting the second target discharge temperature such that as an operation frequency of the compressor 10 increases, the second target discharge temperature increases, friction loss may be compensated. Accordingly, by reflecting an operation frequency of the compressor 10, a more accurate second target discharge temperature may be obtained.
Also, the controller 100 may correct the second target discharge temperature such that as outside temperature increases, the second target discharge temperature increases. Also, the controller 100 may correct the second target discharge temperature such that as outside temperature decreases, the second target discharge temperature decreases.
As outside temperature decreases, heat loss may increase. Accordingly, by correcting the second target discharge temperature such that as outside temperature decreases, the second target discharge temperature decreases, heat loss may be compensated. Accordingly, by reflecting the outside temperature to the second target discharge temperature, a more accurate second target discharge temperature may be obtained.
Referring again to
Referring to
The controller 100 may identify whether the first target discharge temperature exceeds the second target discharge temperature, based on the compared result (402).
According to the first target discharge temperature exceeding the second target discharge temperature (YES in 402), the controller 100 may set the first target discharge temperature to the final target discharge temperature (404).
According to the first target discharge temperature not exceeding the second target discharge temperature (NO in 402), the controller 100 may identify whether the second target discharge temperature exceeds the first target discharge temperature (406).
According to the second target discharge temperature exceeding the first target discharge temperature (YES in 406), the controller 100 may set the second target discharge temperature to the final target discharge temperature (408).
That is, the controller 100 may set a greater one of the first target discharge temperature and the second target discharge temperature to the final target discharge temperature.
As such, a greater one of the first target discharge temperature for forming a normal heating cycle based on outlet temperature and outside temperature and the second target discharge temperature based on pressure of a refrigerant discharged from the compressor 10 and pressure of a refrigerant that enters the compressor 10 may be set to the final target discharge temperature.
Referring to
In an initial stage of a heating operation, a normal heating cycle may not be formed, and accordingly, a second target discharge temperature based on the high-pressure sensor 130 and the low-pressure sensor 140 may have low reliability. In this case, the first target discharge temperature based on outside temperature and outlet temperature, which is less influenced by a heating cycle, may be set to the final target discharge temperature.
During a second section 520 of the heating operation sections 500, the controller 100 may set the second target discharge temperature to the final target discharge temperature. The second section 520 of the heating operation sections 500 may be a time period until the heating operation stops from a time at which the first section 510 terminates.
After a heating cycle is stably formed, the second target discharge temperature based on the high-pressure sensor 130 and the low-pressure sensor 140 may be set to the final target discharge temperature.
Referring again to
The controller 100 may control the expansion valve 40 based on a difference between the final target discharge temperature and discharge temperature detected through the discharge temperature sensor 150.
For example, the controller 100 may control an opening degree of the expansion valve 40 based on a difference and/or a change amount between current discharge temperature and the final target discharge temperature in consideration that decreasing an opening degree of the expansion valve 40 results in an increase of high pressure and an increase of discharge temperature and increasing an opening degree of the expansion valve 40 results in a decrease of high pressure and a decrease of discharge temperature.
As described above, in the case in which the R290 refrigerant is used for a heating operation of the air-to-water heat pump system 1, an outlet temperature range of the water-refrigerant heat exchanger 20 may be between 15° C. or less and 17° C. or more, and an outside temperature range may be between-25° C. or less and 43° C. or more. Because the case in which the R290 refrigerant is used has a relatively wider outlet temperature range and a relatively wider outside temperature range than the case in which an existing R32 or R410A refrigerant is used, a change in density of the refrigerant may be relatively great. Accordingly, in the case in which the expansion valve 40 is controlled based on a degree of target superheat of the compressor 10 like the existing technique, pressure may rise excessively or a heating capacity may become insufficient, which may deteriorate operation reliability of the compressor 10 and a heating capacity.
However, the disclosure may control the expansion valve 40 by setting any one of the first target discharge temperature of the compressor 10 based on outlet temperature and outside temperature or the second target discharge temperature of the compressor 10 based on the high-pressure sensor 130 and the low-pressure sensor 140, to the final target discharge temperature, according to a temperature magnitude and/or a heating operation situation. Therefore, the disclosure may control the expansion valve 40 based on an optimized target discharge temperature in various outlet temperature conditions and outside temperature conditions applied to the air-to-water heat pump system 1, thereby raising operation reliability in various outlet temperature conditions and outside temperature conditions and performing a heating operation with optimal efficiency.
Hereinafter, a heat pump system to which a first temperature sensor 131 and a second temperature sensor 141 are applied, instead of the high-pressure sensor 130 and the low-pressure sensor 140, will be described.
Referring to
The outlet temperature sensor 110 may detect temperature of water heat-exchanged with a refrigerant in the water-refrigerant heat exchanger 20.
The outside temperature sensor 120 may detect an outside temperature.
The first temperature sensor 131 may be positioned around a refrigerant outlet of the water-refrigerant heat exchanger 20.
The first temperature sensor 131 may detect temperature of a refrigerant heat-exchanged in the water-refrigerant heat exchanger 20.
The second temperature sensor 141 may be positioned inside the outdoor heat exchanger 50.
The second temperature sensor 141 may detect temperature of a refrigerant heat-exchanged in the outdoor heat exchanger 50.
The discharge temperature sensor 150 may detect temperature of a refrigerant discharged from the compressor 10.
Referring to
The outside temperature sensor 120 may be positioned around the outdoor heat exchanger 50 to detect an outside temperature.
The first temperature sensor 131 may be positioned around a refrigerant outlet of the water-refrigerant heat exchanger 20.
The first temperature sensor 131 may detect temperature of a refrigerant heat-exchanged in the water-refrigerant heat exchanger 20.
The first temperature sensor 131 may detect temperature of a refrigerant in a high- or medium-temperature state, passed through the water-refrigerant heat exchanger 20, before the refrigerant is expanded in the expansion valve 40.
The second temperature sensor 141 may be positioned inside the outdoor heat exchanger 50.
The second temperature sensor 141 may detect temperature of a refrigerant heat-exchanged in the outdoor heat exchanger 50.
The second temperature sensor 141 may detect temperature of a refrigerant in a low-temperature state, passed through the outdoor heat exchanger 50, before the refrigerant is compressed in the compressor 10.
The discharge temperature sensor 150 may detect temperature of a refrigerant discharged from the compressor 10.
The controller 100 may obtain, during a heating operation, a first target discharge temperature based on output values from the outlet temperature sensor 110 and the outside temperature sensor 120.
The controller 100 may obtain a second target discharge temperature based on output values from the first temperature sensor 131 and the second temperature sensor 141.
The controller 100 may correct the second target discharge temperature based on an operation frequency of the compressor 10 and/or outside temperature.
The controller 100 may set any one of the first target discharge temperature or the second target discharge temperature to a final target discharge temperature.
According to an embodiment, the controller 100 may set a greater one of the first target discharge temperature and the second target discharge temperature to the final target discharge temperature.
According to various embodiments, the controller 100 may set, during a first section of a heating operation, the first target discharge temperature to the final target discharge temperature.
According to various embodiments, the controller 100 may set, during a second section of a heating operation, the second target discharge temperature to the final target discharge temperature.
The controller 100 may control the expansion valve 40 based on the final target discharge temperature. The controller 100 may control the expansion valve 40 based on a difference between the final target discharge temperature and discharge temperature detected by the discharge temperature sensor 150.
Referring to
The controller 100 may detect an outside temperature through the outside temperature sensor 120 (602).
The controller 100 may obtain a first target discharge temperature based on the outlet temperature and the outside temperature (604).
According to an embodiment, the controller 100 may obtain the first target discharge temperature by inputting the outlet temperature and the outside temperature to a correlation function (e.g., a first correlation function).
The controller 100 may detect a temperature of a refrigerant heat-exchanged in the water-refrigerant heat exchanger 20 through the first temperature sensor 131 (606).
The controller 100 may detect a temperature of a refrigerant heat-exchanged in the outdoor heat exchanger 50 through the second temperature sensor 141 (608).
The controller 100 may obtain a second target discharge temperature based on the temperature of the refrigerant heat-exchanged in the water-refrigerant heat exchanger 20 and the temperature of the refrigerant heat-exchanged in the outdoor heat exchanger 50 (610).
According to an embodiment, the controller 100 may obtain the second target discharge temperature by inputting the temperature of the refrigerant heat-exchanged in the water-refrigerant heat exchanger 20 and the temperature of the refrigerant heat-exchanged in the outdoor heat exchanger 50 to an other correlation function (e.g., a third correlation function). The other correlation function (e.g., the third correlation function) may be a program mapped to receive an output value from the first temperature sensor 131 and an output value from the second temperature sensor 141 as input variables and output optimal discharge temperature capable of forming a normal heating cycle under received temperature. Also, the third correlation function may have been mapped to output an optimal discharge temperature that forms a normal heating cycle with a used refrigerant type.
According to various embodiments, the controller 100 may obtain a high-pressure value corresponding to a high-pressure saturation temperature value according to an output value from the first temperature sensor 131. The controller 100 may obtain a low-pressure value corresponding to a low-pressure saturation temperature value according to an output value from the second temperature sensor 141.
The controller 100 may obtain a discharge temperature corresponding to the high-pressure value and the low-pressure value.
The controller 100 may set the discharge temperature based on the high-pressure value, and may set the low-pressure value to the second target discharge temperature.
The controller 100 may set any one of the first target discharge temperature or the second target discharge temperature to a final target discharge temperature (612).
The controller 100 may set a greater one of the first target discharge temperature and the second target discharge temperature to the final target discharge temperature.
The controller 100 may control the expansion valve 40 based on the final target discharge temperature (614).
The controller 100 may control the expansion valve 40 based on a difference between the final target discharge temperature and the discharge temperature detected through the discharge temperature sensor 150.
As described above, the disclosure may control the expansion valve 40 by setting any one of the first target discharge temperature of the compressor 10 based on outlet temperature and the outside temperature or the second target discharge temperature of the compressor 10 based on the first temperature sensor 131 and the second temperature sensor 141, to a final target discharge temperature, according to a temperature magnitude and/or a heating operation situation. Therefore, the disclosure may control the expansion valve 40 based on an optimized target discharge temperature in various outlet temperature conditions and outside temperature conditions applied to the air-to-water heat pump system, thereby raising operation reliability in various outlet temperature conditions and outside temperature conditions and performing a heating operation with optimal efficiency.
So far, various embodiments of the disclosure have been described. However, the technical idea of the disclosure is not limited to the above-described embodiments, and may include various modifications, equivalents, or substitutes of the corresponding embodiments.
According to the disclosure, by controlling the expansion valve based on an optimized target discharge temperature during a heating operation according to an air-to-water heat pump method, operation reliability may increase in various outlet temperature conditions and outside temperature conditions and a heating operation may be performed with optimal efficiency.
The disclosure describes a mono type of an air-to-water heat pump system. However, the disclosure is not limited thereto, and the disclosure may be applied in the same way to a Split type of an air-to-water heat pump system having an evaporator in an outdoor unit and a condenser in an indoor unit.
Effects that can be achieved by the disclosure are not limited to the above-mentioned those, and other effects not mentioned may be clearly understood by one of ordinary skill in the technical art to which the disclosure belongs from the below descriptions.
A heat pump system according to an embodiment of the disclosure may include: a compressor 10; a water-refrigerant heat exchanger 20 connected to the compressor 10; an expansion valve 40 connected to the water-refrigerant heat exchanger 20; an outdoor heat exchanger 50 connected to the expansion valve 40; an outlet temperature sensor 110 configured to detect an outlet temperature of the water-refrigerant heat exchanger 20; an outside temperature sensor 120 configured to detect an outside temperature; a discharge pressure sensor 130 (e.g., a high-pressure sensor 130) configured to detect pressure of a refrigerant discharged from the compressor 10; a suction pressure sensor 140 configured to detect pressure of a refrigerant that enters the compressor 10; and at least one processor 101 configured to obtain, during a heating operation, a first target discharge temperature of the compressor 10 based on an output value from the outlet temperature sensor 110 and an output value from the outside temperature sensor 120, obtain a second target discharge temperature of the compressor based on an output value from the discharge pressure sensor 130 and an output value from the suction pressure sensor 140, set any one of the first target discharge temperature or the second target discharge temperature to a final target discharge temperature, and control the expansion valve 40 based on the final target discharge temperature.
The at least one processor 101 may obtain a high-pressure saturation temperature value according to the output value from the outlet temperature sensor 110, obtain a high-pressure value according to the high-pressure saturation temperature value, obtain a low-pressure saturation temperature value according to the output value from the outside temperature sensor 120, obtain a low-pressure value according to the low-pressure saturation temperature value, and set discharge temperature corresponding to the high-pressure value and the low-pressure value to the first target discharge temperature.
The at least one processor 101 may set, to the high-pressure saturation temperature value, a value obtained by adding a first value to the output value from the outlet temperature sensor 110, and set, to the low-pressure saturation temperature value, a value obtained by subtracting a second value from the output value from the outside temperature sensor 120.
The at least one processor 101 may set, to the second target discharge temperature, discharge temperature corresponding to the output value from the discharge pressure sensor 130 and the output value from the suction pressure sensor 140.
The at least one processor 101 may further correct the second target discharge temperature based on an operation frequency of the compressor 10.
The at least one processor 101 may correct the second target discharge temperature such that as the operation frequency of the compressor 10 increase, the second target discharge temperature increases.
The at least one processor 101 may further correct the second target discharge temperature based on the outside temperature.
The at least one processor 101 may correct the second target discharge temperature such that as the outside temperature increases, the second target discharge temperature increases, and correct the second target discharge temperature such that as the outside temperature decreases, the second target discharge temperature decreases.
The at least one processor 101 may set a greater one of the first target discharge temperature and the second target discharge temperature to the final target discharge temperature.
The at least one processor 101 may set, during a first section of the heating operation, the first target discharge temperature to the final target discharge temperature.
The at least one processor 101 may set, during a second section of the heating operation, the second target discharge temperature to the final target discharge temperature.
The refrigerant may be a R290 refrigerant.
A method of controlling a heat pump system according to an embodiment of the disclosure may include: obtaining, during a heating operation, a first target discharge temperature of a compressor 10 based on outlet temperature of a water-refrigerant heat exchanger 20 and outside temperature; obtaining a second target discharge temperature of the compressor 10 based on pressure of a refrigerant discharged from the compressor 10 and pressure of a refrigerant that enters the compressor 10; setting any one of the first target discharge temperature or the second target discharge temperature to a final target discharge temperature; and controlling an expansion valve 40 based on the final target discharge temperature.
The obtaining of the first target discharge temperature may include setting a high-pressure saturation temperature value according to the outlet temperature, setting a high-pressure value according to the high-pressure saturation temperature value, setting a low-pressure saturation temperature value according to the outside temperature, setting a low-pressure value according to the low-pressure saturation temperature value, and setting discharge temperature corresponding to the high-pressure value and the low-pressure value to the first target discharge temperature.
The obtaining of the second target discharge temperature may include setting, to the second target discharge temperature, discharge temperature corresponding to the pressure of the refrigerant discharged from the compressor 10 and the pressure of the refrigerant that enters the compressor 10.
The method may further include correcting the second target discharge temperature based on at least one of an operation frequency of the compressor 10 or the outside temperature.
The correcting of the second target discharge temperature may include correcting the second target discharge temperature such that as the operation frequency of the compressor 10 increases, the second target discharge temperature increases, correcting the second target discharge temperature such that as the outside temperature increases, the second target discharge temperature increases, and correcting the second target discharge temperature such that as the outside temperature decreases, the second target discharge temperature decreases.
The setting of the final target discharge temperature may include setting a greater one of the first target discharge temperature and the second target discharge temperature to the final target discharge temperature.
The setting of the final target discharge temperature may include setting, during a first section of the heating operation, the first target discharge temperature to the final target discharge temperature.
The setting of the final target discharge temperature may include setting, during a second section of the heating operation, the second target discharge temperature to the final target discharge temperature.
Meanwhile, the disclosed embodiments may be implemented in the form of recording medium that stores instructions executable by a computer. The instructions may be stored in the form of program codes, and when executed by the processor, the instructions may generate a program module to perform the operations of the disclosed embodiments. The recording medium may be implemented as computer-readable recording medium.
The computer-readable recording medium may include all kinds of recording media storing instructions that can be decrypted by a computer. For example, the computer-readable recording medium may be Read Only Memory (ROM), Random Access Memory (RAM), a magnetic tape, a magnetic disk, flash memory, or an optical data storage device.
Also, the computer-readable storage medium may be provided in the form of a non-transitory storage medium, wherein the term ‘non-transitory’ simply means that the storage medium is a tangible device, and does not include a signal (e.g., an electromagnetic wave), but this term does not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium. For example, a ‘non-transitory storage medium’ may include a buffer in which data is temporarily stored.
According to an embodiment, a method according to various embodiments of the disclosure may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed (e.g., downloadable or uploadable) online via an application store (e.g., Play Store™) or between two user devices (e.g., smart phones) directly. When distributed online, at least part of the computer program product (e.g., a downloadable app) may be temporarily generated or at least temporarily stored in the machine-readable storage medium, such as a memory of the manufacturer's server, a server of the application store, or a relay server.
So far, specific embodiments have been shown and described. However, the disclosure is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the technical idea of the disclosure defined by the claims below.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0135714 | Oct 2023 | KR | national |
This application is a continuation application, claiming priority under § 365 (c), of International Application No. PCT/KR2024/012200, filed on Aug. 16, 2024, which is based on and claims the benefit of Korean Provisional Application No. 10-2023-0135714, filed on Oct. 12, 2023, disclosures of which are incorporated by reference herein in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2024/012200 | Aug 2024 | WO |
| Child | 18824826 | US |
