A Water Heater

Abstract

A water heater according to one aspect of the present invention comprises a water tank for containing water, a compressor for compressing a refrigerant, a condenser for supplying heat to water contained in the water tank by heat-exchanging the refrigerant discharged from the compressor, an expander for expanding the refrigerant that has passed through the condenser, and an evaporator for evaporating the refrigerant that has passed through the expander. The evaporator is a heat exchanger comprising a refrigerant coil through which the refrigerant flows and a hot water coil through which the hot water flows. By using hot water, it is possible to prevent frost on the evaporator side and improve operating efficiency and reliability.

Description

Technology Field

[0001] The present invention relates to a water heater and a method of operation thereof. More specifically, it relates to a water heater capable of supplying hot water using a heat pump and a method of operation thereof. Background Technology

[0002] A water heater refers to a device that heats incoming cold water and supplies it to hot water demand points. A heat pump water heater is a hot water supply system utilizing a heat pump, and it is generally composed of a water tank for supplying hot water and a heat pump cycle for heating the water in the tank.

[0003] A heat pump cycle may include a compressor that compresses a refrigerant, a condenser in which the refrigerant discharged from the compressor is condensed, an expander in which the refrigerant passing through the condenser is expanded, and an evaporator in which the refrigerant expanded in the expander is evaporated. In the heat pump cycle, the refrigerant absorbs heat in the evaporator and releases heat in the condenser, and hot water can be produced by transferring heat to water.

[0004] A heat pump water heater discharges air that has been cooled by evaporation from an external heat source through heat pump cycle operation. It may also have a structure that heats the water inside the tank while the condenser heat exchanger in the high-temperature, high-pressure section is in contact with the outside of the tank.

[0005] In heat pump water heaters, when the outdoor heat exchanger uses the outside air as a heat source to evaporate the refrigerant during heating operation, if the outside air temperature drops below the dew point, frost forms on the surface of the outdoor heat exchanger, hindering refrigerant evaporation and potentially reducing heating capacity. Furthermore, if the outside air temperature is low and the temperature of the evaporator heat exchanger drops, the input power required to produce hot water may increase. Additionally, frequent frost formation necessitates repeated defrosting operations, which further reduces operational efficiency.

[0006] Therefore, research is being conducted on technology that can prevent frost buildup in heat pump water heaters and effectively perform defrosting operations.

[0007] For example, prior art Korean Published Patent Application No. 10-2013-0023630 (published on March 8, 2013) sprays hot water through a hot water nozzle (71) to defrost an outdoor heat exchanger and collects the water falling from the bottom in a hot water collection section (72).

[0008] Prior art Korean Published Patent Application No. 10-2013-0023630 states that hot water that has undergone heat exchange at the top of the heat exchanger immediately becomes cold water, and there is a risk of it accumulating as frozen water at the bottom of the heat exchanger. Furthermore, since the hot water is exposed to the outside, there is a possibility of contamination of the circulating water and mechanical failure of pumps, valves, etc.

[0009] Furthermore, prior art Korean Published Patent Application No. 10-2013-0023630 has a configuration that utilizes hot water, but since it is used only for defrosting purposes, the scope of application for the additional configuration for hot water supply is limited. The problem to be solved

[0011] The objective of the present invention is to provide a water heater and a method of operation thereof that can improve operating efficiency and reliability.

[0012] The objective of the present invention is to provide a water heater capable of reducing power consumption and a method of operating the same.

[0013] The objective of the present invention is to provide a water heater capable of continuous operation without frost buildup and a method of operating the same.

[0014] The objective of the present invention is to provide a water heater that facilitates the production of high-temperature water and a method of operating the same. means of solving the problem

[0015] To achieve the above or other purposes, a water heater and a method of operation according to one aspect of the present invention can prevent frost buildup on the evaporator side by using hot water and improve operating efficiency and reliability.

[0016] To achieve the above or other purposes, a water heater according to one aspect of the present invention comprises a water tank containing water, a compressor compressing a refrigerant, a condenser that heat-exchanges the refrigerant discharged from the compressor to supply heat to the water contained in the water tank, an expander in which the refrigerant passing through the condenser expands, and an evaporator in which the refrigerant passing through the expander evaporates. The evaporator is a heat exchanger comprising a refrigerant coil through which the refrigerant flows and a hot water coil through which the hot water flows, thereby preventing frost on the evaporator side by using hot water and improving operating efficiency and reliability.

[0017] Meanwhile, the above evaporator may include at least two rows of refrigerant coils and at least one row of hot water coils.

[0018] In addition, the hot water coil of the first row can be placed between the refrigerant coils of the second row.

[0019] In addition, the hot water coil of the first row may be placed on the opposite side of the refrigerant inlet and outlet of the refrigerant coil of the second row.

[0020] Additionally, to achieve the above or other purposes, a water heater according to one aspect of the present invention may further include a suction duct and a fan that delivers external air introduced through the suction duct to the evaporator.

[0021] In addition, the hot water coil in the first row may be positioned closer to the fan than the refrigerant coil in the second row.

[0022] Meanwhile, to achieve the above or other purposes, a water heater according to one aspect of the present invention may further include a water pump that supplies hot water to the hot water coil.

[0023] In addition, to achieve the above or other purposes, a water heater according to one aspect of the present invention may further include an internal heat exchanger disposed inside the water tank.

[0024] In addition, the hot water coil, the water pump, and the internal heat exchanger can form a closed loop in which hot water circulates.

[0025] In addition, the internal heat exchanger may be placed at the top of the water tank.

[0026] In addition, to achieve the above or other purposes, a water heater according to one aspect of the present invention further comprises a control unit for controlling the water pump, and the control unit may operate the water pump based on at least one of an ambient temperature, an evaporation temperature, a set temperature of the target hot water, and whether or not to perform defrosting operation.

[0027] In addition, the control unit can operate the water pump to perform defrosting operation while maintaining operation for hot water supply during defrosting operation.

[0028] In addition, the control unit can operate the water pump to perform defrosting operation when the evaporation temperature drops below a predetermined temperature or the rate of change of temperature drops below a predetermined rate of change.

[0029] In addition, the control unit can drive the water pump at maximum output during the defrosting operation.

[0030] In addition, the control unit can drive the water pump at minimum output when the ambient temperature is below the reference temperature.

[0031] In addition, the control unit can adjust the output of the water pump so that the temperature difference between the hot water entering the hot water coil and the hot water coming out of the hot water coil is maintained within a certain temperature range.

[0032] In addition, the control unit can drive the water pump at minimum output when the evaporation temperature or the rate of change of the evaporation temperature is within a reference range.

[0033] In addition, the control unit can adjust the output of the water pump so that the evaporation temperature rises compared to the initial level.

[0034] In addition, the control unit can drive the water pump at minimum output when the set temperature of the target hot water is higher than the high temperature standard.

[0035] In addition, the control unit can adjust the output of the water pump so that the temperature difference between the hot water entering the hot water coil and the hot water coming out of the hot water coil is maintained within a certain temperature range, and control the operating frequency of the compressor so that the internal temperature of the water tank maintains the set temperature of the target hot water. Effects of the invention

[0037] According to at least one of the embodiments of the present invention, the operating efficiency and reliability of the water heater can be improved.

[0038] According to at least one of the embodiments of the present invention, the power consumption of a water heater can be reduced.

[0039] According to at least one of the embodiments of the present invention, a water heater capable of continuous operation without frost buildup and a method of operating the same can be provided.

[0040] According to at least one of the embodiments of the present invention, a water heater that facilitates the production of high-temperature water and a method of operating the same can be provided.

[0041] Meanwhile, various other effects will be disclosed directly or implicitly in the detailed description according to the embodiments of the present invention to be described below. Brief explanation of the drawing

[0042] FIG. 1 is a front view of a water heater according to one embodiment of the present invention. FIG. 2 is a diagram illustrating the configuration of a water heater according to one embodiment of the present invention. FIG. 3 is a diagram illustrating the configuration of a water heater according to one embodiment of the present invention. Figures 4a and 4b are diagrams illustrating an evaporative heat exchanger. FIGS. 5 to 7 are drawings illustrating an evaporative heat exchanger according to various embodiments of the present invention. FIGS. 8 to 10 are drawings referenced in the description of a water heater configuration and operation method according to an embodiment of the present invention. FIG. 11 is a drawing referenced in the description of the power consumption reduction effect of a water heater according to one embodiment of the present invention. FIG. 12 is a drawing referenced in the description of a conventional hot water production operation and a hot water production operation according to an embodiment of the present invention. FIG. 13 is a drawing referenced in the description of a water heater operation method according to an embodiment of the present invention. Specific details for implementing the invention

[0043] Embodiments of the present invention will be described in detail below with reference to the attached drawings. However, the present invention is not limited to these embodiments and can be modified in various forms.

[0044] In the drawings, parts unrelated to the description have been omitted to clearly and briefly explain the invention, and the same reference numerals are used for identical or extremely similar parts throughout the specification.

[0045] Meanwhile, the suffixes "module" and "part" for components used in the following description are assigned solely for the ease of drafting this specification and do not inherently confer any particularly significant meaning or role. Accordingly, the terms "module" and "part" may be used interchangeably.

[0046] Additionally, in this specification, terms such as first, second, etc. may be used to describe various elements, but these elements are not limited by these terms. These terms are used only to distinguish one element from another.

[0047] FIG. 1 is a front view of a water heater according to one embodiment of the present invention, and FIG. 2 is a diagram illustrating the configuration of a water heater according to one embodiment of the present invention.

[0048] Referring to FIG. 1 and FIG. 2, a water heater (1) according to embodiments of the present invention may include a water tank section (10) including a water tank (11) for supplying hot water, and a heat pump cycle (20) for heating the water in the water tank (11).

[0049] The water tank section (10) may include a water tank (11) that holds water inside, an inlet pipe (12a) that supplies water to the water tank (11), and an outlet pipe (12b) that discharges heated water from the water tank (11).

[0050] An inlet pipe (12a) for supplying water to a water tank (11) may be formed at the bottom of the water heater (1). The end of the inlet pipe (12a) may be formed to be recessed into the interior of the water heater (1) or may be formed to protrude outside the water heater (1). The inlet pipe (12a) is formed in a structure into which a water supply source, such as a hose, can be inserted or connected, so that it can be connected to the water supply source to supply water into the interior of the water tank (11).

[0051] An outlet pipe (12b) for discharging water heated in the water tank (11) may be formed at the top of the water tank (11). The end of the outlet pipe (12b) may be formed to be recessed into the interior of the water heater (1) or may be formed to protrude outside the water heater (1). The outlet pipe (12b) is formed in a structure into which a water supply source, such as a hose, can be inserted or connected, so that it can be connected to the water supply source to discharge water heated in the water tank (11) to a hot water demand location.

[0052] A display (30) that displays one or more pieces of information may be placed on the outer wall of the case of the water heater (1). For example, a display (30) that displays the temperature of the hot water discharged from the water heater (1) may be placed near the water outlet pipe (12b) of the water heater (1). The display (30) may be formed by being attached to the outer wall of the water heater (1) or may be embedded in the outer wall to display the temperature. The display (30) may simultaneously provide not only the temperature of the hot water discharged from the water heater (1) but also other information required by the hot water demand source.

[0053] The water tank (11) can be placed indoors, and water flowing into the water tank (11) through the inlet pipe (12a) can be heated by the heat pump (20) and heater (60) and discharged through the outlet pipe (12b).

[0054] A water heater (1) may include a compressor (21) that compresses a refrigerant, a condenser (22) that supplies heat to water by exchanging heat between the high-temperature, high-pressure refrigerant discharged from the compressor (21) and the water inside the water tank (11), an expander (23) that reduces the pressure of the refrigerant condensed through the condenser (22), and an evaporator (24) that evaporates the low-temperature, low-pressure refrigerant reduced through the expander (23) by exchanging heat with external air.

[0055] The condenser (22) may be placed on the outer wall of the water tank (11) placed indoors. The condenser (22) may be placed with a minimum spacing to exchange heat with the water inside the water tank (11), and may be placed attached to the outer wall of the water tank (11).

[0056] The condenser (22) can be positioned to be attached to the lower region of the water tank (11), and a heating region (H) can be formed inside the water tank (11), which is a region where water is heated by receiving heat from the refrigerant flowing through the condenser (22).

[0057] A first temperature sensor (51) for measuring the temperature of water stored in the heating area (H) may be placed near the heating area (H), and a second temperature sensor (52) for measuring the temperature of water stored in the upper part of the water tank (11) may be placed above the water tank (11).

[0058] The first temperature sensor (51) can measure the average temperature of the water stored in the heating area (H), and the second temperature sensor (52) can measure the average temperature of the water discharged through the water outlet pipe (12b).

[0059] The first temperature sensor (51) can be placed in the middle of the heating area (H) or at the middle of the condenser (22) attached to the water tank (11), and can be placed at a height point that is 0.21 of the total height from the lowest side when the total height of the water tank (11) is considered as 1.

[0060] The second temperature sensor (52) can be placed at the same height as the water outlet pipe (12b) and can be placed at a height point that is 0.74 times the total height from the lowest side when the total height of the water tank (11) is considered as 1.

[0061] The second temperature sensor (52) and the water outlet pipe (12b) are positioned higher than the condenser (22) and the heating area (H), and the water inlet pipe (12a) may be positioned below the condenser (22) or below the condenser (22).

[0062] The water heater (1) may include an additional auxiliary heat source for rapid heating. For example, an auxiliary heater (60) that supplies additional heat to the heating area (H) may be placed near the heating area (H) along with the heat pump (20), and the auxiliary heater (60) may be placed at the bottom of the water tank (11).

[0063] The heat pump (20) may further include a fan (25) that generates external air flow to help heat exchange in the evaporator (24).

[0064] The water heater (1) may include a control unit (30) that controls the operation of the compressor (21) and the overall operation of the water heater (1). The control unit (30) can control not only the compressor (21) but also the operation of the fan (25) and the heater (60).

[0065] The control unit (30) is wirelessly or wiredly connected to the first temperature sensor (51) and the second temperature sensor (52) and can receive signals transmitted from the first temperature sensor (51) and the second temperature sensor (52). Additionally, the control unit (30) can control the operation of the compressor (21), fan (25), and heater (60) based on the signals received from the first temperature sensor (51) and the second temperature sensor (52).

[0066] For example, the control unit (30) can turn off the compressor (21) if the second temperature sensor (52) and the set temperature differ within a predetermined temperature difference (e.g., 2.5 degrees Celsius), or drive the compressor (21).

[0067] In some cases, the condenser (22) may be placed on the outer wall of the water tank (11) which is placed indoors, and the compressor (21), expander (23), evaporator (24), and fan (25) may be placed outdoors.

[0068] More preferably, the condenser (22) may be placed on the outer wall of the water tank (11) placed indoors, and the compressor (21), expander (23), evaporator (24), and fan (25) may be placed on the upper part of the water tank (11) placed indoors. That is, the entire compact water heater (1) product may be placed indoors.

[0069] FIG. 3 is a diagram illustrating the configuration of a water heater according to one embodiment of the present invention.

[0070] Referring to FIG. 1 and FIG. 3, a water heater (1) according to one embodiment of the present invention has a water tank section (10) including a hot water tank (11) disposed at the bottom of the product, and a heat pump cycle (20) disposed at the top of the product.

[0071] The heat pump machine room (20a) may have a structure that accommodates the compressor (21), the evaporator (24), and the expander (23) of the heat pump cycle (20), and is separated from the water tank section (10).

[0072] In the heat pump machine room (20a), an intake duct (27) for external air intake and a discharge duct (28) for internal air discharge may be formed. The intake duct (27) may be connected to the upper side of the heat pump machine room (20a), and the discharge duct (28) may be connected to the side of the heat pump machine room (20a). Additionally, the water tank (11) may be placed on the lower side of the heat pump machine room (20a).

[0073] The water tank section (10) at the bottom of the product may further include a water tank (11), an inlet pipe (12a) formed at the bottom of the water tank (11), and an outlet pipe (12b) formed at the top of the water tank (11).

[0074] The heat pump cycle (20) may include a compressor (21) that compresses the refrigerant, a condenser (22) that supplies heat to the water by exchanging heat between the high-temperature, high-pressure refrigerant discharged from the compressor (21) and the water inside the water tank (11), an expander (23) that reduces the pressure of the refrigerant condensed through the condenser (22), and an evaporator (24) that evaporates the low-temperature, low-pressure refrigerant reduced through the expander (23) by exchanging heat with the outside air. The refrigerant circulating in the heat pump cycle (20) exchanges heat with water and air in the heat exchangers, the condenser (22) and the evaporator (24).

[0075] In the heat pump cycle (20) at the top of the product, the refrigerant circulates through the refrigerant circulation pipe according to the operation of the compressor (21).

[0076] The high-temperature, high-pressure refrigerant discharged from the compressor (21) passes through the condenser (hereinafter referred to as a condensation heat exchanger) (22) surrounding the water tank (11) and exchanges heat with the cold water inside the water tank (11).

[0077] Through heat exchange, the temperature of the cold water inside the water tank (11) rises, and the refrigerant of the condensing heat exchanger (22) circulates to the upper heat pump cycle (20) as a liquid refrigerant in a subcooled state.

[0078] The subcooled refrigerant passes through the expansion valve (23) again and is circulated to the evaporator (hereinafter referred to as the evaporation heat exchanger) (24) in a low-temperature, low-pressure refrigerant state. At this time, the fan (25) and the fan motor (25m) can help heat exchange by circulating external air.

[0079] The fan motor (25m) and the fan (25) rotate to draw in outside air into the heat pump machine room (20a) through the intake duct (27) and send the outside air to the evaporator heat exchanger (24) so ​​that the refrigerant can absorb heat. Meanwhile, the cooled air is discharged to the outside of the heat pump machine room (20a) through the discharge duct (28).

[0080] At this time, if the temperature of the outside air passing through the evaporator heat exchanger (24) is low, frost may form on the surface of the heat exchanger (24), causing frost to form. If the airflow is blocked due to frost, the performance and efficiency of the water heater (1) decrease.

[0081] Typically, when frost forms on the surface of the heat exchanger, a defrosting operation is performed by periodically operating the heat pump in a reverse cycle. When frost forms on the evaporator heat exchanger (24), the water heater (1) can perform defrosting by sending high-temperature, high-pressure refrigerant to the evaporator heat exchanger (24) through the four-way valve (23), and then resume the hot water production operation.

[0082] The water heater (1) may include a low-temperature evaporative heat exchanger (24) and a high-temperature condensation heat exchanger (22) enclosed on the outer wall of the water tank (11) for producing hot water.

[0083] The main role of the evaporator heat exchanger (24) is to cause the refrigerant to evaporate by obtaining a heat source from the air for the cooled low-temperature, low-pressure refrigerant. The evaporator heat exchanger (24) mainly uses a fin / tube type heat exchanger.

[0084] Figures 4a and 4b are diagrams illustrating an evaporative heat exchanger.

[0085] Referring to FIGS. 4a and 4b, a fin / tube type heat exchanger (240) may be formed with a tube (241) through which refrigerant flows and a fin (242) coupled to the outer surface of the tube (241) to release heat of the refrigerant to the outside. Additionally, the fin / tube type heat exchanger (240) may include a supply pipe for introducing refrigerant into the tube (241) and a discharge pipe for discharging the refrigerant.

[0086] The refrigerant passing through the inside of the tube (241) can exchange heat with the air in contact with the outer surface of the tube (241) and the fin (242).

[0087] The above tube (241) is preferably formed of a material that allows heat to be transferred effectively so as to effectively release the heat of the refrigerant to the outside, has sufficient strength to withstand the internal pressure caused by the refrigerant flowing inside, and is not corroded by the refrigerant. For example, the above tube (241) may be a copper tube.

[0088] The above fin (242) is preferably formed of a material that conducts heat well so that the heat of the refrigerant can be effectively released to the outside. For example, the above fin (242) may be made of an aluminum fin.

[0089] A U-shaped tube (241) is commonly used. A U-shaped tube (241) may include a pair of tube sections formed parallel to each other, and a bending section that is bent into a U-shape between the pair of tube sections. A refrigerant may pass through one of the pair of tube sections, then pass through the bending section, and then pass through the other of the pair of tube sections.

[0090] A fin / tube type heat exchanger (240) may include a plurality of tubes (241) through which heat exchange between a refrigerant flowing through the fins and air takes place, and to improve heat exchange efficiency, the plurality of tubes (241) may be formed into a plurality of rows.

[0091] FIG. 4a illustrates a two-row structure of a first row (L1) and a second row (L2), in which a plurality of tubes (241) may be positioned in the front and rear directions in the direction of the airflow (Air). Based on the airflow (Air) side, the first row (L1) may be named the front row and the second row (L2) the rear row. Additionally, a fin (242) may be formed on each of the tubes (241) of the first row (L1) and the second row (L2).

[0092] The tubes (241) of the first row (L1) are positioned upstream in the direction of the airflow so as to exchange heat with the air, and the tubes (241) of the second row (L2) are positioned downstream in the direction of the airflow so as to exchange heat with the air. Multiple tubes (241) may be positioned spaced apart in a direction perpendicular to the direction of air flow.

[0093] Meanwhile, multiple tubes (241) can be connected to form a branched structure considering heat exchange efficiency. For example, the tubes (241) of the first column (L1) and the tubes (241) of the second column (L2) can be connected by configuring the branches in various ways to minimize the path difference. Additionally, the fin / tube type heat exchanger (240) may have multiple structures in which the tubes (241) of the first column (L1) and the tubes (241) of the second column (L2) are connected. Furthermore, it is possible for one or more U-shaped tubes (241) to be arranged across the first column (L1) and the second column (L2) and connected to other tubes (241).

[0094] As described with reference to FIGS. 4a and 4b, the evaporative heat exchanger (24) uses a fin / tube type heat exchanger comprising a refrigerant coil consisting of a tube (241) through which the refrigerant mainly flows and fins (242) formed on the tube (241).

[0095] An evaporator (evaporative heat exchanger, 24) according to one embodiment of the present invention includes a refrigerant coil through which refrigerant flows and a hot water coil through which hot water flows. That is, the evaporative heat exchanger (24) according to one embodiment of the present invention may additionally include a hot water coil through which hot water flows in addition to the existing refrigerant coil. Since the evaporative heat exchanger (24) according to one embodiment of the present invention includes a configuration in which both refrigerant and water flow, it can be named a refrigerant-water integrated heat exchanger.

[0096] The control unit (240) supplies hot water to the hot water coil, and the heat from the hot water flowing through the hot water coil can prevent frost from forming on the refrigerant coil side. Accordingly, by preventing frost formation in advance, performance degradation due to frost formation can be prevented, and in addition, the defrosting operation of the reverse cycle for frost removal can be prevented, thereby improving efficiency.

[0097] Meanwhile, the fin / tube type heat exchanger comprises a refrigerant coil in which tubes (241) through which most of the refrigerant flows are arranged in a 2-row or 3-row configuration. An evaporator heat exchanger (24) according to one embodiment of the present invention may add heat to the heat transfer and intermediate rows of the refrigerant coil in the existing fin-tube type heat exchanger, or may arrange a refrigerant / water branch and distribution coil mixed in individual refrigerant tubes.

[0098] FIGS. 5 to 7 are drawings illustrating an evaporative heat exchanger according to various embodiments of the present invention.

[0099] Referring to FIGS. 5 and 6, an evaporative heat exchanger (24) according to one embodiment of the present invention may include at least two rows (L1, L2) of refrigerant coils (240) and at least one row (W1) of hot water coils (100).

[0100] Referring to FIG. 5, the hot water coil (100) of the first row (W1) can be placed between the refrigerant coils (240) of the second row (L1, L2).

[0101] Referring to FIG. 6, in order to facilitate heat exchange between fins, the hot water coil (100) of the first row (W1) is positioned upstream in the direction of the airflow (Air) and can be placed in the front row of the refrigerant coil (240) of the second row (L1, L2). Additionally, if the hot water coil (100) of the first row (W1) is placed in the front row of the refrigerant coil (240) of the second row (L1, L2), the structure is simple and it is easy to install an inlet / outlet structure for hot water circulation.

[0102] Referring to FIG. 6, piping is connected to the refrigerant coil (240) to circulate the refrigerant. A refrigerant inlet and outlet are arranged on one side of the refrigerant coil (240) of the two rows (L1, L2). In this case, the hot water coil (100) of the first row (W1) may be arranged on the opposite side of the refrigerant inlet and outlet of the refrigerant coil (240) of the two rows (L1, L2). Accordingly, an inlet / outlet structure for hot water circulation of the hot water coil (100) can be arranged without obstructing the refrigerant circulation of the refrigerant coil (240).

[0103] A water heater (1) according to one embodiment of the present invention may further include a fan (25) that generates an external air flow to assist in heat exchange in an evaporator (24). The fan (25) can draw in external air from a suction duct (27), generate an air flow, and deliver the external air to an evaporator heat exchanger (24). In this case, the hot water coil (100) of the first row (W1) may be positioned closer to the fan (25) than the refrigerant coil (240) of the second row (L1, L2).

[0104] A refrigerant-water integrated evaporative heat exchanger (24) according to one embodiment of the present invention is configured to allow hot water to circulate by adding a heat transfer or an intermediate heat transfer to a conventional evaporative heat exchanger (240), and can be configured by mixing coils of refrigerant and hot water as shown in FIGS. 5 to 7. In addition, heat exchange between refrigerant and water can be further enhanced as air is delivered by a fan (25).

[0105] Referring to FIG. 7, the refrigerant / water branch and distribution coil (240, 100) can be arranged in a mixed manner.

[0106] According to one embodiment of the present invention, by applying a refrigerant-water integrated evaporator heat exchanger in which hot water heat exchange is added to the evaporator heat exchanger (low temperature) of a heat pump, continuous operation without frosting is possible and product efficiency is improved.

[0107] According to one embodiment of the present invention, to implement a refrigerant-water integrated evaporative heat exchanger, an internal heat exchanger is inserted into a water tank, and a hot water circulation device connected to the heat of the evaporative heat exchanger is configured. By raising the low-pressure side evaporation temperature according to product operation control, power consumption for compressor operation can be reduced, continuous operation is possible without defrosting, and hot water of a higher quality than conventional methods can be produced.

[0108] Through the present invention, efficient operation of a heat pump water heater is possible, thereby providing effects such as reduced power consumption, continuous operation without freezing, production of high-temperature water through low-pressure increase, reduced heater usage in cryogenic environments, and increased operating efficiency.

[0109] FIGS. 8 to 10 are drawings referenced in the description of a water heater configuration and operation method according to an embodiment of the present invention. FIGS. 8 and 9 are solid lines illustrating a configuration and path for an anti-fogging operation that supplies hot water to a hot water coil (100), and FIG. 10 is solid lines illustrating a configuration and path for simultaneously performing hot water operation and defrosting operation (anti-fogging operation).

[0110] Referring to FIGS. 8 to 10, a water heater (1) according to one embodiment of the present invention may further include a water pump (110) that supplies hot water to a hot water coil (100).

[0111] The above water pump (110) is connected to an inlet / outlet port (not shown) formed in the water tank (110) and can supply hot water from the water tank (110) to the hot water coil (100).

[0112] Meanwhile, a water heater (1) according to one embodiment of the present invention may further include an internal heat exchanger (120) disposed inside the water tank (110). Meanwhile, the internal heat exchanger (120) may be disposed on the upper part of the water tank (110).

[0113] The above hot water coil (100), the water pump (110), and the internal heat exchanger (120) can form a hot water circulation structure in a closed loop through which hot water circulates.

[0114] A refrigerant-water integrated evaporative heat exchanger (24) according to one embodiment of the present invention can be configured by connecting a part of the refrigerant coil (240) to a hot water circulation unit within a conventional fin tube type evaporative heat exchanger.

[0115] The hot water circulation unit can circulate hot water using a water pump (110) by inserting an internal heat exchanger (120) inside the water tank (11). The hot water circulation unit is configured as a closed loop by connecting the internal heat exchanger (120) inside the water tank (11), and hot water circulation can be performed using a water pump (110).

[0116] Meanwhile, referring to FIG. 8, the water heater (1) may further include an accumulator (21a) that extracts gaseous refrigerant from the supplied refrigerant and supplies it to the compressor (21).

[0117] According to an embodiment, the water heater (1) may further include a four-way valve (23) capable of controlling the flow direction of the refrigerant.

[0118] Referring to FIG. 10, while performing hot water production operation according to the heat pump cycle described with reference to FIG. 2 and FIG. 3, defrosting operation (frost-preventing hot water operation) is possible using the water pump (110) and the internal heat exchanger (120). That is, simultaneous operation of hot water operation and defrosting operation is possible. Therefore, defrosting operation can be performed without performing the conventional reverse cycle operation and without switching the operation of the four-way valve (23). Thus, the four-way valve (23) can be removed. That is, defrosting operation can be performed by operating the water pump (110) while maintaining the conventional hot water production without the reverse cycle operation of the water heater (1).

[0119] Depending on the implementation, the four-way valve (23) can be left as is, and defrosting operation can also be performed through reverse cycle operation of the conventional method depending on accumulated freezing or hot water temperature conditions.

[0120] Meanwhile, according to one embodiment of the present invention, since hot water is used as a heat source for preventing frost formation, there is a concern about performance degradation, and appropriate control is required to ensure effective use when adjustment of the evaporation temperature is necessary.

[0121] The control unit (40) can control components within the water heater (1), such as the water pump (110), to perform hot water operation that prevents frost formation. Additionally, the control unit (40) can perform hot water circulation control under various heat pump cycle operating conditions.

[0122] The above control unit (40) can operate the water pump (110) based on at least one of the ambient temperature, evaporation temperature, set temperature of the target hot water, and whether or not to operate the defrost.

[0123] The above control unit (40) can operate the water pump (110) to perform defrosting operation while maintaining operation for hot water supply during defrosting operation. Defrosting operation according to one embodiment of the present invention is performed by supplying hot water to the hot water coil (100) to remove frost, and can be performed in the same manner as frost prevention operation, which supplies hot water in advance before frost occurs. In this case, defrosting can be performed as a simultaneous operation without stopping the hot water production operation for hot water supply.

[0124] Meanwhile, according to one embodiment of the present invention, reverse cycle operation may be performed as in conventional defrosting operation for rapid defrosting.

[0125] Meanwhile, the control unit (40) can operate the water pump (110) to perform defrosting operation when the evaporation temperature drops below a predetermined temperature or the rate of change of temperature drops below a predetermined rate of change. At this time, the control unit (40) can drive the water pump (110) at maximum output during the defrosting operation.

[0126] Meanwhile, the control unit (40) can drive the water pump (110) at minimum output when the ambient temperature is below a reference temperature. At this time, the control unit (40) can adjust the output of the water pump (110) so that the temperature difference between the hot water entering the hot water coil (100) and the hot water coming out of the hot water coil (100) is maintained within a certain temperature range. According to one embodiment of the present invention, the usage rate of the heater (60), which is an auxiliary heat source, can be reduced and the overall operating efficiency increased in a cryogenic environment.

[0127] Meanwhile, the control unit (40) can drive the water pump (110) at a minimum output when the evaporation temperature or the rate of change of the evaporation temperature is within a reference range. In this case, the control unit (40) can adjust the output of the water pump (110) so that the evaporation temperature rises compared to the initial level.

[0128] Meanwhile, the control unit (40) can drive the water pump (110) at minimum output when the set temperature of the target hot water is above the high temperature standard. At this time, the control unit (40) can adjust the output of the water pump (110) so that the temperature difference between the hot water entering the hot water coil (100) and the hot water coming out of the hot water coil (100) is maintained within a certain temperature range. In addition, the control unit (40) can control the operating frequency of the compressor (21) so that the internal temperature of the water tank (11) maintains the set temperature of the target hot water.

[0129] In the event that frost forms on the evaporator heat exchanger of a conventional heat pump water heater, defrosting operation is performed by controlling the flow of high-temperature, high-pressure refrigerant flowing through the conventional condenser heat exchanger and operating a reverse cycle to flow to the evaporator heat exchanger to remove the frost from the evaporator heat exchanger.

[0130] According to one embodiment of the present invention, when the outdoor temperature is low and frosting and defrosting operations occur frequently, hot water is circulated to the side of the evaporator heat exchanger (24) to raise the evaporation temperature, thereby enabling continuous operation without frosting. Additionally, according to one embodiment of the present invention, defrosting operations can be performed by circulating hot water to the side of the evaporator heat exchanger (24) to remove frost.

[0131] According to one embodiment of the present invention, when the evaporation temperature is low and the internal temperature of the water tank (11) is high, hot water is circulated to the side of the evaporation heat exchanger (24) to increase the evaporation temperature and reduce the power consumption of the compressor (21), thereby increasing the product operation efficiency.

[0132] FIG. 11 is a drawing referenced to the explanation of the power consumption reduction effect of a water heater according to one embodiment of the present invention, and shows the test results of heating water from a temperature of 10 degrees to 55 degrees.

[0133] Figure 11 (a) shows the result of a conventional water heater operation in which 12 defrosting operations are performed at an evaporation temperature of 0 degrees until the water is heated from 10 degrees to 55 degrees, and a total heating time of 12 hours is required.

[0134] FIG. 11(b) illustrates the result of operating a water heater according to one embodiment of the present invention, where the water is heated from 10 degrees to 55 degrees, the defrosting operation is performed 0 times at an evaporation temperature of 3 degrees, and the total heating time is 9 hours. In this way, by circulating hot water to the side of the evaporation heat exchanger (24), the evaporation temperature can be raised and the product operation efficiency can be increased.

[0135] In addition, according to one embodiment of the present invention, when it is desired to increase the discharge temperature, hot water is circulated to increase the evaporation temperature and form a high-temperature cycle, thereby increasing the hot water temperature of the water tank and enabling high-temperature discharge.

[0136] FIG. 12 is a drawing referenced in the description of a conventional hot water production operation and a hot water production operation according to an embodiment of the present invention.

[0137] Figure 12 (a) shows a conventional hot water production operation, where condensation = 55 degrees, evaporation = 0 degrees, and power consumption is 1005 W.

[0138] Figure 12(b) shows that, according to an embodiment of the present invention, the evaporation temperature can be increased to condensation = 55 degrees and evaporation = 2 degrees. As the evaporation temperature increases, the compression work is reduced, and the power consumption can be reduced to 966 W, which is 96% of the level of the example in Figure 12(a).

[0139] Figure 12 (c) shows that, by controlling the high-temperature water output according to an embodiment of the present invention, the condensation temperature and the evaporation temperature can be raised to 60 degrees and 5 degrees, respectively. In this case, the power consumption is 1010 W, which is similar to the example in Figure 12 (a), but high-temperature hot water can be produced with similar power consumption.

[0140] FIG. 13 is a drawing referenced in the description of a water heater operation method according to an embodiment of the present invention, and shows the temperature point used during control, the configuration and path for performing hot water production operation for hot water supply, and the path in solid lines.

[0141] When a situation arises where hot water circulation is required in the evaporative heat exchanger (24) while performing a hot water production operation for hot water supply, the control unit (40) can switch to a defrosting operation or additionally drive a hot water circulation unit to perform simultaneous operation.

[0142] For example, the control unit (40) can perform hot water circulation operation with the hot water coil (100) in four cases: when starting operation under extremely low ambient conditions (-7°C or lower), when operating at an evaporation temperature (0°C or lower) where frost is likely to occur, when entering defrosting operation due to frost, and when the set temperature of the target hot water (55°C or higher) is high.

[0143] For a more specific example, if the rate of change of T2 temperature drops by 5 degrees after 3 minutes of operation, or if the T2 temperature drops to -20 degrees or lower, it is determined that defrosting operation is required, and the control unit (40) can power on the water pump (110) to start operation. At this time, the control unit (40) can drive the water pump (110) at maximum output (Max RPM).

[0144] Meanwhile, the control unit (40) can release the defrosting operation and switch back to the normal hot water production operation when the T2 temperature rises above 20 degrees or the hot water circulation operation is for a predetermined time (e.g., 3 minutes).

[0145] The control unit (40) can determine that evaporation temperature control is required when the condition of a rate of change of 1 degree or more is satisfied for 3 minutes while the outdoor air temperature is 7 degrees or less and / or the T2 temperature is 1 degree or less. The control unit (40) can perform evaporation temperature control through hot water circulation operation simultaneously with hot water supply operation.

[0146] The control unit (40) can start operation by turning on the power of the water pump (110). At this time, the control unit (40) can drive the water pump (110) at a minimum output (Min RPM). In addition, the control unit (40) can control the flow rate step of the water pump (110) so that the hot water temperature difference T (T4 - T5) maintains a predetermined temperature (e.g., 3 degrees). In addition, the control unit (40) can control the operation so that the temperature rises by 2 degrees compared to the initial evaporation temperature (T2).

[0147] Meanwhile, the control unit (40) can release the evaporation temperature control when the outdoor air temperature is 7 degrees or higher and / or the hot water temperature difference (T4-T5) is 1 degree or lower. In this case, the hot water supply operation and the hot water circulation operation can be performed simultaneously and then switched back to the hot water supply operation state.

[0148] The control unit (40) can determine that high-temperature water control is required when the water outlet setting temperature is set to a high temperature of 55 degrees or higher. The control unit (40) can perform high-temperature water control through hot water circulation operation simultaneously with hot water supply operation.

[0149] The control unit (40) can start operation by turning on the power of the water pump (110). At this time, the control unit (40) can drive the water pump (110) at a minimum output (Min RPM). Additionally, the control unit (40) can control the flow rate step of the water pump (110) so that the hot water temperature difference T (T4 - T5) maintains a predetermined temperature (e.g., 3 degrees). Additionally, the control unit (40) can control the operating frequency of the compressor (21) so that the internal temperature (T6) of the water tank maintains 55 degrees.

[0150] Meanwhile, the control unit (40) can release the high-temperature water control when a predetermined time (e.g., 3 minutes) has elapsed after the internal temperature (T6) of the water tank has reached a temperature higher than the set temperature and / or when the hot water temperature difference T (T4-T5) is 1 degree or less.

[0151] According to one embodiment of the present invention, using a refrigerant-water integrated heat exchanger in a heat pump water heater to utilize hot water for cycle control is effective in improving the operating efficiency and reliability of the product.

[0152] According to one embodiment of the present invention, the low-pressure side evaporation temperature in a heat pump cycle can be increased to reduce the power consumption of the compressor operation and ensure efficient product performance.

[0153] According to one embodiment of the present invention, product operation is possible even during defrosting with continuous operation without frosting, and hot water production operation is possible.

[0154] According to one embodiment of the present invention, the low-pressure side temperature can be raised under low-temperature conditions to reduce the usage rate of the auxiliary heater (60) when starting the product.

[0155] According to one embodiment of the present invention, if necessary, the low-pressure side temperature can be increased to increase the high pressure, thereby enabling the production of high-temperature water.

[0156] The water heater and the method of operation according to the present invention are not limited to the configurations and methods of the embodiments described above; rather, all or part of each embodiment may be selectively combined to allow for various modifications to be made.

[0157] Furthermore, although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. Various modifications are possible by those skilled in the art without departing from the essence of the invention as claimed in the claims, and such modifications should not be understood individually from the technical spirit or perspective of the present invention. Explanation of the symbols

[0159] Compressor: 21 Condenser: 22 Evaporator: 24 Refrigerant coil: 240 Hot water coil: 100 Water pump: 110

Claims

Claim 1 A water heater comprising: a water tank for holding water inside; a compressor for compressing refrigerant; a condenser for supplying heat to water held in the water tank by heat-exchanging the refrigerant discharged from the compressor; an expander for expanding the refrigerant that has passed through the condenser; and an evaporator for evaporating the refrigerant that has passed through the expander; wherein the evaporator is a heat exchanger comprising a refrigerant coil through which refrigerant flows and a hot water coil through which hot water flows; and further comprising a water pump for supplying hot water to the hot water coil; and a control unit for controlling the water pump; wherein the control unit operates the water pump based on at least one of an ambient temperature, an evaporation temperature, a set temperature of the target hot water, and whether or not to perform defrosting operation, and drives the water pump at a minimum output when the set temperature of the target hot water is above a high temperature standard. Claim 2 A water heater according to claim 1, wherein the evaporator comprises at least two rows of refrigerant coils and at least one row of hot water coils. Claim 3 A water heater according to paragraph 2, characterized in that the hot water coil in the first row is disposed between the refrigerant coils in the second row. Claim 4 A water heater according to paragraph 2, characterized in that the hot water coil of the first row is positioned on the opposite side of the refrigerant inlet and outlet of the refrigerant coil of the second row. Claim 5 A water heater according to paragraph 2, further comprising: a suction duct; and a fan that delivers external air introduced through the suction duct to the evaporator. Claim 6 A water heater according to claim 5, characterized in that the hot water coil in the first row is positioned closer to the fan than the refrigerant coil in the second row. Claim 7 delete Claim 8 A water heater according to claim 1, further comprising an internal heat exchanger disposed inside the water tank. Claim 9 A water heater according to claim 8, wherein the hot water coil, the water pump, and the internal heat exchanger form a closed loop through which hot water circulates. Claim 10 A water heater according to claim 9, wherein the internal heat exchanger is positioned at the top of the water tank. Claim 11 delete Claim 12 A water heater according to claim 1, wherein the control unit operates the water pump to perform defrosting operation while maintaining operation for hot water supply during defrosting operation. Claim 13 A water heater according to claim 1, wherein the control unit operates the water pump to perform defrosting operation when the evaporation temperature drops below a predetermined temperature or the rate of change of temperature drops below a predetermined rate of change. Claim 14 A water heater according to claim 1, wherein the control unit drives the water pump at maximum output during the defrosting operation. Claim 15 A water heater according to claim 1, wherein the control unit drives the water pump at minimum output when the ambient temperature is below a reference temperature. Claim 16 A water heater according to claim 15, wherein the control unit adjusts the output of the water pump so that the temperature difference between the hot water entering the hot water coil and the hot water coming out of the hot water coil is maintained within a certain temperature range. Claim 17 A water heater according to claim 1, wherein the control unit drives the water pump at minimum output when the evaporation temperature or the rate of change of the evaporation temperature is within a reference range. Claim 18 In claim 17, the water heater is characterized in that the control unit adjusts the output of the water pump so that the evaporation temperature rises compared to the initial level. Claim 19 delete Claim 20 A water heater according to claim 1, wherein the control unit adjusts the output of the water pump so that the temperature difference between the hot water entering the hot water coil and the hot water coming out of the hot water coil is maintained within a certain temperature range, and controls the operating frequency of the compressor so that the internal temperature of the water tank maintains the set temperature of the target hot water.

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