US20240183586A1

US20240183586A1 - Heating system using heat pump and air heating device

Info

Publication number: US20240183586A1
Application number: US18/525,857
Authority: US
Inventors: Dong Keun Lee; In Soo Hwang
Original assignee: Kyungdong Navien Co Ltd
Current assignee: Kyungdong Navien Co Ltd
Priority date: 2022-12-01
Filing date: 2023-12-01
Publication date: 2024-06-06
Also published as: KR20240082033A

Abstract

A heating system according to the present invention includes a heat pump provided to heat inflow air using a circulating refrigerant; an air heating device provided to heat air passing through the heat pump using water heated by burning a fuel, an external air temperature acquisition unit provided to acquire an external air temperature that is a temperature of external air, and a processor electrically connected to the heat pump, the air heating device, and the external air temperature acquisition unit. In a heating mode, when the external air temperature is greater than a lower limit and less than an upper limit of a balance band, which is a predetermined temperature range, the processor is configured to control the air heating device and the heat pump so that the air is heated by the air heating device and the heat pump.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Korean Patent Application No. 10-2022-0165925, filed on Dec. 1, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a heating system using a heat pump and air heating device.

Description of the Related Art

The existing air conditioning system mainly used in North America performs cooling of air supplied to each room through a heat transfer using a heat pump and perform heating of air supplied to each room through a heat transfer using a gas air heating device. The gas/air heating device may operate by burning a gas as fuel and transferring heat generated from the gas to air. The heat pump may operate by receiving electric power and circulating the refrigerant using the electric power as power.
The heat pump may operate in a refrigeration mode by circulating the refrigerant through a refrigeration cycle of compression-condensation-expansion-evaporation. Among these, heat absorption, i.e., cooling may be performed, and the heat absorbed by the refrigerant may be dissipated at a portion at which the condensation occurs. However, when the refrigerant is reversely circulated in the heat pump, the portion at which the evaporation occurs and the portion at which the condensation occurs are reversed, and thus, the heat dissipation may occur at the portion at which the heat absorption occurs, resulting in heating rather than cooling.
Thus, in addition of the gas/air heating device, the heating may be performed by the heat pump. The gas air heating device and the heat pump may be used for the heating. The heat pump operates efficiently at relatively high temperatures, but does not operate efficiently at sub-zero temperatures due to an small amount of heat to be provided. The gas air heating device may provide a large amount of heat, but require a lot of fuel and energy to operate.

SUMMARY OF THE INVENTION

An aspect of the present invention provides a heating system in which an air heating device and a heat pump appropriately operate to efficiently perform heating.
According to an aspect of the present invention, there is provided a heating system including: a heat pump provided to heat inflow air using a circulating refrigerant; an air heating device provided to heat air passing through the heat pump using water heated by burning a fuel; an external air temperature acquisition unit provided to acquire an external air temperature that is a temperature of external air; and a processor electrically connected to the heat pump, the air heating device, and the external air temperature acquisition unit, wherein, in a heating mode, when the external air temperature is greater than a lower limit and less than an upper limit of a balance band, which is a predetermined temperature range, the processor is configured to control the air heating device and the heat pump so that the air is heated by the air heating device and the heat pump.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a conceptual view illustrating a situation in which heating is performed using a heating system according to an embodiment of the present invention;

FIG. 2 is a conceptual view illustrating a situation in which cooling is performed using the heating system according to an embodiment of the present invention;

FIG. 3 is a graph illustrating a relationship between PE-COP of an air heating device and a heat pump and an external air temperature;

FIG. 4 is a graph illustrating a relationship between an operation state of the air heating device and a heat pump of the heating system and an external air temperature according to an embodiment of the present invention;

FIG. 5 is a flowchart illustrating an operation order of the heating system according to an embodiment of the present invention; and

FIG. 6 is a conceptual view illustrating a situation in which hot water is produced and cooled using a heating system according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In adding of reference numerals to components of each drawing, it should be noted that the same components have the same numerals as much as possible even if the components are displayed on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted to avoid making the subject matter of the present invention unclear.
Also, in the description of the embodiments of the present invention, the terms such as first, second, A, B, (a) and (b) may be used. These terms are only used to distinguish the component from other components, and the essence, sequence, or order of the corresponding component is not limited by the term. It should be understood that when an element is described as being “connected”, communicated”, “coupled”, or “connected” to another element, the former may be directly connected or jointed to the latter or may be “connected”, communicated”, “coupled” or “connected” to the latter with a third component interposed therebetween.
FIG. 1 is a conceptual view illustrating a situation in which heating is performed using a heating system 1 according to an embodiment of the present invention. FIG. 2 is a conceptual view illustrating a situation in which cooling is performed using the heating system 1 according to an embodiment of the present invention;
Referring to the drawings, the heating system 1 according to an embodiment of the present invention may include a heat pump 10, an air heating device 20, and an external air temperature acquisition unit 34, and a processor.
In the specification of the present invention, the expressions of upstream and downstream may be based on a flow direction of a fluid. For example, if the fluid flows from left to right, the left may correspond to the upstream, and the right may correspond to the downstream.
Components illustrated as dotted lines in FIGS. 1, 2 , and 6 basically mean parts that do not operate in that situation or passages in which a fluid does not flow, but operate or flow in a line that does not impair the content of the control that has to be performed in that situation.

Air Heating Device (20)

The air heating device 20 is a component that heats air using water heated by burning fuel. The air heating device 20 is disposed to heat the air passing through a heat pump 10, which will be described later. That is, the air heating device 20 may be disposed at a downstream side of the heat pump 10 along an air flow direction.
The air heating device 20 may include a furnace case 200. Other components of the air heating device 20 may be embedded into the furnace case 200. A processor, which will be described later, may be disposed inside the furnace case 200 and may be coupled to an inner surface of the furnace case 200.
A furnace supply port 201 provided to allow external air to flow from the outside to the inside of the furnace case 200 may be disposed in the furnace case 200. The furnace supply port 201 is necessary for the air heating device 20 to receive the external air. The external air temperature acquisition unit, which will be described later, is disposed at the furnace supply port 201 to acquire an external air temperature, which is a temperature of introduced external air.
To briefly describe the overall air heating mechanism performed in the air heating device 20, the air heating device 20 heats water stored in an expansion tank 25 in a water heater 21 and then transfers the heated water to a heating heat-exchanger 23. The heated water transferred to the heating heat-exchanger 23 may heat air transferred from a finance fan 24, and then, the heated air may be transferred to each room. A furnace main passage 11 may connect the expansion tank 25, the water heater 21, and the heating heat-exchanger 23 to each other to allow the water to be circulated. The furnace main passage may be provided as a pipe or a soft hose. Hereinafter, each component will be described in more detail.
The air heating device 20 may include the expansion tank 25. Water may be stored in the expansion tank 25. Water may be replenished from an external water source to the expansion tank 25 through the water replenishment passage, and the water replenishment passage may be controlled to open and close by the water replenishment valve 253. The expansion tank 25 may be provided to accommodate a volume change due to a change in water temperature. The expansion tank 25 may be configured in an open manner to accommodate volume expansion by water.
The water may be introduced from the expansion tank 25 into the heating heat-exchanger 23 via the water heater 21 through the furnace main passage. The water passing through the heating heat-exchanger 23 may be recovered again into the expansion tank 25.
A water level sensor 251 that detects a water level inside the expansion tank 25 may be disposed in the expansion tank 25. When the water level sensor 251 confirms that the water level in the expansion tank 25 is below a predetermined water level, the water replenishment valve 253 may be opened to replenish water in the expansion tank 25.
A drain tube 252 may be disposed in the expansion tank 25 to reduce the water level by draining water when the water level in the expansion tank 25 is too high.
Since the water discharged from the expansion tank 25 contains foreign substances, a strainer 254 may be disposed to filter the foreign substances. The water discharged from the expansion tank 25 may be transferred to the water heater 21 through the strainer 254.
A circulation pump 27 may be disposed in a region disposed between the expansion tank 25 and the water heater 21 in the furnace main passage. The circulation pump 27 may pump water so that the water is circulated within the furnace main passage. The circulation pump 27 may be electrically connected to the processor.
The water heater 21 may be a component that heats inflow water and discharges the water. To heat water, the water heater 21 may cause a combustion reaction and transfer the heat generated from the combustion reaction to the water.
The water heater 21 may include a burner 211 and a heat exchange part 212. The burner 211 may cause a combustion reaction. Therefore, the burner 211 may receive a fuel and air and may cause the combustion reaction to generate flame in a mixture of the fuel and air using a spark plug. For this operation, the burner 211 may include a blower that supplies air, a fuel nozzle that injects a fuel, and a spark plug that generates spark for ignition.
The burner 211 may further include a mixing chamber to allow the fuel and air to be mixed in the mixing chamber. Heat and a combustion gas may be generated through the combustion reaction and then may be transferred to water. The fuel may be a natural gas used for power generation such as methane, ethane, etc., or may be oil, but the type is not limited thereto. The flame generated by the combustion reaction generated by the burner 211 may be disposed in an internal space of a combustion chamber disposed below the burner 211. The combustion chamber may be a wet-type combustion chamber. For example, a water pipe through which water passes may be disposed on a side surface of the combustion chamber to surround the side surface of the combustion chamber. In a process of dissipating heat inside the combustion chamber to the outside of the combustion chamber, some of the heat may be transferred to the water in the water pipe. The combustion chamber may be a dry-type combustion chamber surrounded by an insulator.
The heat exchanger part 212 may transfer heat generated from the burner 211 to water. The heat exchange part 212 may be provided in a fin-tube type including a pipe-type water heating heat-exchange tube connected to the furnace main passage through which water passes, and a heat-exchange housing that defines a space through which the combustion gas generated by the combustion reaction passes through the outside of a water heating heat exchange pipe. However, the heat exchanger part 212 is not limited thereto and may be provided in a plate type.
The heat exchange part 212 may include a sensible heat exchange part and a latent heat exchange part. The sensible heat exchange part may be a portion that heats the water by receiving radiant heat generated by the combustion reaction and heat of the combustion gas, and the latent heat exchange part may be a portion that heats the water using latent heat of condensation of the combustion gas.
An upstream water temperature sensor 291 and a downstream water temperature sensor 292 may be disposed at upstream and downstream sides of the water heater 21, respectively, on the furnace main passage 11 to acquire a temperature of water introduced into the water heater 21 and a temperature of discharged water. A flow sensor 293 for acquiring a flow rate of water flowing in the main passage may be disposed on the furnace main passage.
A heating/hot water valve 28 may be disposed between the water heater 21 and the heating heat-exchanger 23 on the furnace main passage. The heating/hot water valve 28 may determine a passage so that the water heated and discharged from the water heater 21 flows to the heating heat-exchanger 23 or to a hot water tank 26. The heating/hot water valve 28 may be a three-way valve and may be controlled so that water selectively flow to either the hot water tank 26 or the heating heat-exchanger 23, or an opening degree is adjusted to allow water to be distributed or transferred to the hot water tank 26 and the heating heat-exchanger 23.
The heating heat-exchanger 23 may exchange heat between the water and air. The heating heat-exchanger 23 may receive the heated water from the water heater 21 to be heat-exchanged with the air to be discharged for the heating. The heating heat-exchanger 23 may include an air heating heat-exchange tube through which water heated by the water heater 21 flows. The air heating heat-exchange tube may be provided in a pipe shape so that water flows through the inside, and air supplied by the furnace fan 24 flows through the outside, and may be provided to provide a winding passage in the front-rear and left-right directions. The air heating heat exchange pipe may be made of a material containing aluminum and copper.
The air heating device 20 may include a furnace fan 24. The furnace fan 24 may be provided to transfer air to the heating heat-exchanger 23. The furnace fan 24 includes components such as a motor and a blade and may be electrically connected to the processor. Therefore, as the furnace fan 24 is electrically controlled to operate, the motor may allow the blade to rotate so that air is blown. The furnace fan 24 may include an impeller and the like to forcibly transfer air. Air passing through the heat pump 10 may be transferred to the furnace fan 24. External air may be transferred to the furnace fan 24 through the furnace supply port 201.
A circulation process of the air from the fan 24 will be described as follows. Air introduced into the furnace fan 24 may be transferred to the heating heat-exchanger 23. The supplied air may pass through the heating heat-exchanger 23. As the air passes through the heating heat-exchanger 23, the air may be heated by receiving heat from the water passing through the heating heat-exchanger 23. The heated air may be transferred to each room of a house through a discharge duct. The inflow air, which is air transferred to each room and returned to the heating system 1 may be introduced again into the furnace fan 24 through a suction duct via the heat pump 10. The suction duct may communicate with an indoor space and be provided to guide indoor air to the heat pump 10.
An intermediate temperature acquisition unit 32 for acquiring a temperature of corresponding air may be disposed in a region of the furnace case 200 in which air is transferred from the heat pump 10 to the furnace fan 24. An exhaust air temperature acquisition unit 33 for acquiring a temperature of corresponding air may be disposed in a region of the furnace case 200 in which air passing through the heating heat-exchanger 23 is discharged.
The hot water tank 26 may produce hot water by exchanging heat between water transferred from the water heater 21 and water transferred from an external water source. A pipe connected to the furnace main passage may pass inside the hot water tank 26, and water transferred from the outside may be stored around the pipe. Thus, the heated water may pass through the pipe to transfer heat to the water outside the pipe, and the water outside the pipe may be heated so that hot water is discharged to a place at which the hot water is needed.

Heat Pump (10)

The heat pump 10 is provided to heat inflow air using circulating of a refrigerant. The heat pump 10 may cool the air. The heat pump 10 may include an indoor unit 101 disposed adjacent to the air heating device 20 to transfer or absorb heat to inflow air and an outdoor unit 102 that absorbs heat to be transferred to the inflow air or releases the heat transferred from the inflow air. The indoor unit 101 and the outdoor unit 102 may be connected to each other to heat or cool the air through thermally opposing operations.
The heat pump 10 may include a main passage of the heat pump 10. While the refrigerant flows through the main passage of the heat pump 10, the refrigerant may be compressed, condensed, expanded, and evaporated. As illustrated in FIG. 1 , when the condensation occurs in the indoor unit 101, heating may be performed on the air, and as illustrated in FIG. 2 , when the evaporation occurs in the indoor unit 101, cooling may be performed on the air. When the heating is performed, as illustrated in FIG. 1 , at least one of the air heating device 20 or the heat pump 10 may operate for the heating, and when the cooling is performed, as illustrated in FIG. 2 , only the furnace fan 24 may operate in the air heating device 20, and the heat pump 10 may be operate for the cooling.
The indoor unit 101 of the heat pump 10 may include an indoor unit case. An inflow air temperature acquisition unit 31 may be disposed in the indoor unit case to acquire a temperature of an inflow air flowing into the indoor unit 101.
The indoor unit 101 may include an indoor coil 11. The indoor coil 11 may function as a condenser when performing the heating and as an evaporator when performing the cooling. When the refrigerant passing through the indoor coil 11 performs the heating, the refrigerant may be condensed to transfer latent heat to air passing around the indoor coil 11. When the refrigerant passing through the indoor coil 11 performs the cooling, the refrigerant may be evaporated to take heat out of the air passing around the indoor coil 11.
The indoor unit 101 may include an indoor valve 16. The indoor valve 16 may function as an expansion valve that expands the refrigerant when performing the cooling. The indoor valve 16 may be a thermostatic expansion valve, in which a degree of superheat of the refrigerant is constantly maintained in a manner in which, when the degree of superheat of the refrigerant increases, the expansion valve is opened, and when the degree of the superheat of the refrigerant decreases so that the refrigerant is saturated in the indoor coil 11. The indoor valve 16 may be disposed upstream of the indoor coil 11 on the main passage of the heat pump 10 based on the refrigerant flow direction during the cooling. The indoor valve 16 may be opened or bypassed during the heating.
The outdoor unit 102 may be mainly disposed in an outdoor space to serve to release unnecessary heat or absorb necessary heat in the indoor space. The outdoor unit 102 may include an outdoor coil 121 for performing this function. The outdoor coil 121 may function as an evaporator when performing the heating and as a condenser when performing the cooling. When the refrigerant passing through the outdoor coil 121 performs the cooling, the refrigerant may be condensed to transfer latent heat to air passing around the outdoor coil 121. When the refrigerant passing through the outdoor coil 121 performs the heating, the refrigerant may be evaporated to take the heat out of the air passing around the outdoor coil 121. To ensure smooth heat exchange, an outdoor fan 122 may be disposed around the outdoor coil 121 to rotate so that an air flow is generated around the outdoor coil 121. The outdoor coil 121 and the outdoor fan 122 may constitute an outdoor coil part 12.
The outdoor unit 102 may include a compressor 13. The compressor 13 may serve to compress the refrigerant passing therethrough. The outdoor unit 102 may include a four-way valve 17 disposed adjacent to the compressor 13. When the heating is performed, the four-way valve 17 may be configured so that the passage of the refrigerant is provided in a shape in which the refrigerant discharged from the outdoor coil 121 is introduced into the compressor 13 to flow to the indoor coil 11, or when the cooling is performed, the four-way valve 25 may be configured so that the passage of the refrigerant is provided in a shape in which the refrigerant discharged from the indoor coil 11 is introduced into the compressor 13 to flow to the outdoor coil 121.
The outdoor unit 102 may include an outdoor valve 14. The outdoor valve 14 may act as an expansion valve that expands the refrigerant when performing the heating. The outdoor valve 14 may be an electronic expansion valve that electronically controls a flow rate. The outdoor valve 14 may be disposed upstream of the outdoor coil 121 on the main passage of the heat pump 10 based on the refrigerant flow direction during the heating. The outdoor valve 14 may be bypassed through a check valve 15 during the cooling. The check valve 15 may permit the flow of the refrigerant from the outdoor coil 121 to the indoor coil 11 during the cooling, and block the flow of refrigerant from the indoor coil 11 to the outdoor coil 121 during the heating so that the refrigerant flows only through the outdoor valve 14.

Temperature Acquisition Unit

The heating system 1 according to an embodiment of the present invention may include various temperature acquisition units for acquiring a temperature of air. The temperature acquisition units may be electrically connected to the processor to transmit the acquired temperature to the processor. Each of the temperature acquisition units may be a thermocouple, a thermistor, etc. for acquiring the temperature of the air to transmit the acquired temperature to the processor, but the types of the temperature acquisition units are not limited thereto.
The external air temperature acquisition unit 34, which is one of the temperature acquisition units, is provided to acquire an external air temperature, which is a temperature of the external air. The external air temperature acquisition unit 34 may be disposed on the furnace supply port 201.
The inflow air temperature acquisition unit 31, which is one of the temperature acquisition units, may acquire an inflow air temperature, which is a temperature of air flowing into the heat pump 10. The inflow air temperature acquisition unit 31 may be disposed in the indoor unit case.
The intermediate temperature acquisition unit 32, which is one of the temperature acquisition units, can acquire the temperature of the air passing through the heat pump 10 and flowing into the air heating device 20. Thus, the intermediate temperature acquisition unit 32 may be disposed between the indoor coil 11 and the furnace fan 24.
The exhaust air temperature acquisition unit 33, which is one of the temperature acquisition units, may acquire a temperature of the air discharged through the heating system 1. Thus, the exhaust air temperature acquisition unit 33 may be disposed at the downstream side of the heating heat-exchanger 23 based on the air flow direction.

Processor

FIG. 3 is a graph illustrating a relationship between PE-COP of the air heating device 20 and the heat pump 10 and an external air temperature. FIG. 4 is a graph illustrating a relationship between an operation state of the air heating device 20 and the heat pump 10 of the heating system 1 and an external air temperature according to an embodiment of the present invention. FIG. 5 is a flowchart illustrating an operation order of the heating system 1 according to an embodiment of the present invention.
The air heating device 20 according to an embodiment of the present invention may further include a controller. The controller may include a processor and a memory. The processor may be a component including elements capable of logical operations that perform a control command and may include a central processing unit (CPU). The processor may be connected to various components to perform the control by transmitting a signal according to the control command to each component and may be connected to various sensors or acquisition units to receive acquired information in the form of signals. Thus, in an embodiment of the present invention, the processor may be electrically connected to various components provided in the heating system 1. Since the processor is electrically connected to each component, a communication module connected through a conductive wire or capable of wireless communication may be further provided so that the processor communicates with the components.
The control command performed by the processor may be stored in the memory and utilized. The memory may be a device such as a hard disk drive (HDD), a solid state drive (SSD), a server, a volatile media, or a non-volatile media, but the type is not limited thereto. In addition, data necessary for the processor to perform the operation may be stored in the memory.
The processor may be electrically connected to the heat pump 10, the air heating device 20, and the temperature acquisition unit. The processor may control operations of the heat pump 10 and the air heating device 20 based on the acquired temperature.
In FIG. 3 , PE-COP, which is a primary energy conversion coefficient of performance (i.e., a coefficient of performance acquired by comparing an amount of primary energy that has to be consumed to obtain a predetermined amount of electrical energy with cooling and heating performance) of the air heating device 20 is illustrated as a slide line, PE-COP when the heat pump 10 operates at a load of about 100% is illustrated as a is a broken line in which lines having different lengths are alternately illustrated, and PE-COP when the heat pump 10 operates to a load of about 80% is illustrated as a dotted line, and PE-COP when the heat pump 10 operates to a load of about 60% is illustrated as a dashed line.
Referring to FIG. 3 , COP of the air heating device 20 may be maintained constantly regardless of the external air temperature, but the PE-COP of the heat pump 10 may be changed to tend to increase as the external air temperature increases. In addition, as the operation load of the heat pump 10 decreases, the PE-COP is higher at the same external air temperature. However, if the operation load of the heat pump 10 decreases, a high PE-COP may be obtained, but the heat pump 10 may not be able to absorb the entire heating load. Thus, if the target heating load, which is the total required heating load, is known, the processor may adjust the operation load of the heat pump 10 to have a high PE-COP, and the air heating device 20 may supplement and heat the operation load of the heat pump 10 determined by a target heating load by a limit value so that the entire heating system 1 performs an efficient operation having the high COP.
As illustrated in FIG. 4 , a balance band that is in a range of a predetermined temperature may be calculated from the external air temperature of FIG. 3 and the PE-COP graph of each device. After acquiring the external air temperature using the external air temperature acquisition unit 34 (S10) to receive the acquired external air temperature to the processor, the processor may compare the balance band with the external air temperature (S20) When the external air temperature is within the balance band, the heat pump 10 and the air heating device 20 operate together, and the air heating device 20 assists the heating of the heat pump 10. When the external air temperature is above the upper limit of the balance band, only the heat pump 10 may operate. When the external air temperature is below the lower limit of the balance band, only the air heating device 20 may operate. The processor may use the balance band that has already been input and stored in the memory, and may also calculate and use the balance band using other information stored in the memory. The balance band may illustratively range from −5 degrees Celsius to +5 degrees Celsius, but the range is not limited thereto.
When the external air temperature is between the lower limit and the upper limit of the balance band, which is in the predetermined temperature range, the processor may control the air heating device 20 and the heat pump 10 so that the air is heated by the air heating device 20 and the heat pump 10. When the external air temperature is below the lower limit of the balance band, the processor may control the air heating device 20 and the heat pump 10 so that the air is heated by the air heating device 20, and the heat pump 10 does not operate. When the external air temperature is above the upper limit of the balance band, the processor may control the air heating device 20 and the heat pump 10 so that the air is heated by the heat pump 10, and the air heating device 20 does not operate. However, the above situation shows the control of the processor in a heating mode, in which the heating has to be performed, and may not be applied in a defrost operation mode, a hot water production mode, and a dehumidification mode.
When the external air temperature is greater than the lower limit and less than the upper limit of the balance band and thus is within the balance band, the processor may acquire an inflow air temperature using the inflow air temperature acquisition unit 31 (S30). A load distribution may be determined from the target heating load calculated based on the inflow air temperature acquired by the inflow air temperature acquisition unit 31 and the external air temperature acquired by the external air temperature acquisition unit 34, and thus, the heating load of the air heating device 20 and the heat pump 10 may be determined according to the load distribution, and the air heating device 20 and the heat pump 10 may be controlled to operate accordingly. The heating load of the heat pump 10 may be determined from the target heating load and the external air temperature, and thus, the heat pump 10 may operate accordingly (S40), and the air heating device 20 may supplementally operate according to the heating load that is equal to the value obtained by subtracting the heating load of the heat pump 10 from the target heating load (S50).
For example, as illustrated in FIG. 3 , when the load of the heat pump 10 is about 60%, the PE-COP value may match that of the air heating device 20 at the external temperature of approximately −10 degrees Celsius, and when the load of the heat pump 10 is about 100%, the PE-COP value may match that of the air heating device 20 at the external air temperature of approximately 0 degrees. Then, when assuming that a relationship between the load and temperature, in which the PE-COP of the heat pump 10 matches that of the air heating device 20 at the external air temperature between about 0 degrees and about −10 degrees Celsius, is has a linear relationship, the relational expression may be calculated. According to the relationship, when obtaining the outside temperature, the heat pump 10 may find the load that is capable of appearing the optimal PE-COP at the corresponding external air temperature, and the air heating device 20 may supplementally operate according to the heating load that is equal to the value obtained by subtracting the heating load of the heat pump 10 from the target heating load.
The target heating load may be obtained by multiplying the air flow rate determined by the furnace fan 24 and a specific heat of air multiplied by a difference between the target exhaust air temperature and the inflow air temperature.
A mapping table that maps optimal load distribution for each target heating load and the target heating load may be stored in the memory. According to this mapping table, the processor may distribute the load to control the air heating device 20 and the heat pump 10. However, the processor may also calculate and use the mapping table using information received and information stored in the memory. The optimal load distribution may be heating load distribution calculated to achieve the highest efficiency of the heating system 1 based on the external air temperature and the target heating load. The optimal load distribution may be determined further based on a rate of fuel and a rate of electricity used by the heat pump 10.
For example, after illustrating a graph like FIG. 3 so that a vertical axis corresponds to a cost required for the heating rather than PE-COP, the heating load may be distributed according to the cost, as if the heating load of the heat pump 10 and the air heating device 20 is distributed, based on FIG. 3 , and then, the heat pump 10 and the air heating device 20 may be controlled based on the distributed heating load.
When the heat pump 10 operates in the defrost operation mode to remove frost generated on the coil, the processor may operates to control the air heating device 20 so as to heat the air passing through the heat pump 10. In the defrost operation mode, since the heat pump 10 operates to perform the cooling, the air heating device 20 may perform additional heating to the extent of cooling performed by the heat pump 10, and as a result, the heating system 1 may be prevented from being affected by the cooling due to the defrost operation. The processor may control the air heating device 20 to supplement an amount of heat from the air heating device 20 to the extent that an amount of heat transferred to the air decreases due to the defrost operation of the heat pump 10.
In the dehumidifying mode for providing dry air, the processor may control the heat pump 10 and the air heating device 20 so that the heat pump 10 cools the inflow air, and the air heating device 20 heats the air passing through the heat pump 10. Since moisture in the air introduced during the cooling process of the heat pump 10 is condensed to be removed, after dehumidification is achieved in the heat pump 10, the cooling effect, which is a side effect of the dehumidification process, is removed through the heating of the air heating device 20.

Another Embodiment

FIG. 6 is a conceptual view illustrating a situation in which hot water is produced and cooled using a heating system 1 b according to another embodiment of the present invention.
The heating system 1 b according to another embodiment of the present invention is the same as the heating system 1 according to an embodiment of the present invention except that a waste heat recovery heat exchanger 40 b and a waste heat valve 18 b therefor are further provided, and a control of an associated processor is added, and thus, differences therebetween will be further explained, and also, the description of the heating system 1 according to an embodiment of the present invention will be applied as it is to other portions.
The waste heat recovery heat exchanger 40 b exchanges heat between water discharged from a hot water tank 26 b for production of hot water in the water circulating in an air heating device 20 b and a refrigerant discharged from a compressor 13 b and flowing to an indoor coil 11 b in the refrigerant circulating in the heat pump 10 b. The processor may control the waste heat valve 18 b disposed downstream of the compressor 13 b and a four-way valve 17 b based on a flow direction of the refrigerant during the cooling process so that the refrigerant discharged from the compressor 13 b is directed to the waste heat recovery heat exchanger 40 b rather than to the outdoor coil part 12 b. The waste heat valve 18 b may be a three-way valve and may be controlled so that the refrigerant discharged from the compressor 13 b is directed to an outdoor coil 121 b or to the waste heat recovery heat exchanger 40 b. As the refrigerant bypasses the waste heat recovery heat exchanger 40 b, the refrigerant may not be transferred to an outdoor valve 14 b and a check valve 15 b.
The refrigerant discharged from the waste heat recovery heat exchanger 40 b may be transferred to the indoor coil 11 b through the indoor valve 16 b. Thus, in the waste heat recovery heat exchanger 40 b, the refrigerant may be condensed by exchanging heat with water in the air heating device 20 b rather than with air. That is, the waste heat recovery heat exchanger 40 b functions as a condenser in the cooling process of the heat pump 10 b.
The water discharged from a hot water tank 26 b may be heated through the waste heat recovery heat exchanger 40 b and provided to the expansion tank 25 b. Thus, production of hot water and cooling may be achieved at the same time.
The processor may control the heat pump 10 b so that an outdoor fan 122 b provided in the heat pump 10 b does not operate when the air heating device 20 b produces the hot water.
Therefore, according to the present invention, the air heating device and the heat pump may appropriately operate according to the external air temperature to efficiently perform the heating.
All components may be coupled to one another to form a single body or to operate as a single body, but the present disclosure is not limited thereto. That is, one or more components are selectively coupled and operated within the scope of the present disclosure. The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. Unless terms used in the present disclosure are defined differently, the terms may be construed as meaning known to those skilled in the art. Terms such as terms that are generally used and have been in dictionaries should be construed as having meanings matched with contextual meanings in the art. In this description, unless defined clearly, terms are not ideally, excessively construed as formal meanings.
The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention. Thus, the embodiment of the present invention is to be considered illustrative, and not restrictive, and the technical spirit of the present invention is not limited to the foregoing embodiment. Therefore, the scope of the present invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention.

Claims

1. A heating system comprising:

a heat pump provided to heat inflow air using a circulating refrigerant;

an air heating device provided to heat air passing through the heat pump using water heated by burning a fuel;

an external air temperature acquisition unit provided to acquire an external air temperature that is a temperature of external air; and

a processor electrically connected to the heat pump, the air heating device, and the external air temperature acquisition unit,

wherein, in a heating mode, when the external air temperature is greater than a lower limit and less than an upper limit of a balance band, which is a predetermined temperature range, the processor is configured to control the air heating device and the heat pump so that the air is heated by the air heating device and the heat pump.

2. The heating system of claim 1, further comprising an inflow air temperature acquisition unit provided to acquire an inflow air temperature that is a temperature of air introduced into the heat pump and electrically connected to the processor,

wherein, in the heating mode, when the external air temperature is greater than the lower limit and less than the upper limit of the balance band, which is the predetermined temperature range, the processor is configured to control the air heating device and the heat pump so that a load distribution is determined from a target heating load calculated based on the inflow air temperature and the external air temperature to allow the air heating device and the heat pump to operate according to the load distribution.

3. The heating system of claim 2, wherein the load distribution determined from the target heating load is determined based on a primary energy coefficient of performance (PE-COP) value of the heat pump according to the external air temperature.

4. The heating system of claim 2, wherein the load distribution determined from the target heating load is determined based on a fuel rate and an electricity rate used by the heat pump.

5. The heating system of claim 1, wherein, in the heating mode, when the external air temperature is below the lower limit of the balance band, the processor is configured to control the air heating device and the heat pump so that the air is heated by the air heating device, and the heat pump does not operate, and

in the heating mode, when the external air temperature is above the upper limit of the balance band, the processor is configured to control the air heating device and the heat pump so that the air is heated by the heat pump, and the air heating device does not operate.

6. The heating system of claim 1, wherein, when the heat pump operates in a defrost operation mode, the processor is configured to control the air heating device so that the air heating device operates to heat air passing through the heat pump.

7. The heating system of claim 1, wherein the air heating device is provided to further produce hot water by circulating water, and

the heating system further comprises a waste heat recovery heat exchanger configured to exchange heat between the water circulating for the production of the hot water in the air heating device and the refrigerant circulating in the heat pump.

8. The heating system of claim 7, wherein, when the hot water is produced by the air heating device, the processor is configured to control the heat pump so that an outdoor fan provided in the heat pump does not operate.

9. The heating system of claim 1, wherein, in a dehumidifying mode, the processor is configured to control the heat pump and the air heating device so that the heat pump is configured to cool the inflow air, and the air heating device is configured to heat the air passing through the heat pump.

10. The heating system of claim 1, wherein the air heating device comprises a furnace case, and

the processor is disposed inside the furnace case.

11. The heating system of claim 1, wherein the external air temperature acquisition unit is disposed at a furnace supply port provided so that the air heating device receives the external air.

12. The heating system of claim 1, wherein the air heating device is disposed at a downstream side of the heat pump along an air flow direction.

13. The heating system of claim 1, wherein the heat pump includes an indoor unit configured to transfer heat to the inflow air or absorb heat to the inflow air,

wherein the indoor unit includes an indoor coil functioning as a condenser when the heating system performs the heating and functioning as an evaporator when the heating system performs the cooling.