Heat supply apparatus and method for controlling the same

Abstract

The invention relates to a heat supply apparatus and a control method thereof. A heat supply device according to the present invention comprises: a compressor that compresses a refrigerant; a first heat exchanger that exchanges heat between the air and the refrigerant; a second heat exchanger that exchanges heat between the water and the refrigerant; a conversion valve for conveying the refrigerant discharged from the compressor to the first heat exchanger or the second heat exchanger; the first liquid pipe is connected with the first heat exchanger and the second heat exchanger; a second liquid pipe connected in parallel with the first liquid pipe and connecting the first heat exchanger and the second heat exchanger; a first expansion valve which is disposed in the first liquid pipe and expands the flowing refrigerant; and a second expansion valve which is disposed in the second liquid pipe and expands the flowing refrigerant. The aperture of the second expansion valve may be formed to be larger than the aperture of the first expansion valve. Therefore, the flow rate of the refrigerant can be adjusted according to the operation mode.

Description

Technical Field

[0001] The present invention relates to a heat supply device, and more particularly to a heat supply device that uses a refrigerant discharged from a compressor to heat or cool water flowing into an indoor space. Background Art

[0002] The heat supply device may refer to a device that supplies heat energy or cold energy to water flowing into the indoor space.

[0003] The heat supply device may have a structure including a compressor, a first heat exchanger for heat exchange between air and refrigerant, and a second heat exchanger for heat exchange between water supplied to the room and the refrigerant. That is, the heat supply device may use an air source heat pump (AWHP) device for heat exchange between air and water using a refrigerant. Water flowing in the second heat exchanger for heat exchange between water and refrigerant may receive cold energy or heat energy of the refrigerant and be supplied to the indoor space.

[0004] The heat supply device may mainly operate in a heating operation mode in which high-pressure refrigerant is sent to the second heat exchanger, but may also operate in a cooling operation mode in which liquid refrigerant is sent to the second heat exchanger depending on conditions.

[0005] There is a capacity difference between the first heat exchanger for heat exchange between air and refrigerant and the second heat exchanger for heat exchange between water and refrigerant. Mainly, the capacity of the first heat exchanger is formed to be larger than the capacity of the second heat exchanger. Therefore, when the heat supply device performs the heating operation mode and the cooling operation mode, problems caused by the flow difference of the refrigerant may occur.

[0006] In addition, when the heat supply device is used in a cold region, the first heat exchanger may be frosted, and in an extremely low temperature environment, the water supplied to the second heat exchanger may become below a specified level.

[0007] EP 2015 / 2940407 B1 discloses a common AWHP cycle and a structure in which only one expansion valve is arranged between a first heat exchanger for heat exchange between air and refrigerant and a second heat exchanger for heat exchange between water supplied to the room and refrigerant. This structure still has the problem of difficulty in adjusting the flow difference generated when changing between the cooling operation mode and the heating operation mode. In addition, in an extremely low temperature environment, there is a problem that control for additional measures cannot be performed even if the water flowing into the second heat exchanger is maintained above a specified level. Summary of the invention

[0008] An object of the present invention is to provide a heat supply device capable of adjusting the amount of refrigerant supplied to heat exchangers having different capacities according to an operation mode.

[0009] Another problem to be solved by the present invention is to provide a heat supply device that can prevent water flowing into the second heat exchanger from being cooled and can be defrosted by the first heat exchanger even in an extremely low temperature environment.

[0010] Another problem to be solved by the present invention is to provide a control method for a heat supply device capable of defrosting only the first heat exchanger or simultaneously defrosting the first heat exchanger and the second heat exchanger in consideration of temperature conditions.

[0011] Problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

[0012] In order to solve the above problems, the heat supply device of the embodiment of the present invention includes: a compressor, which compresses the refrigerant; a first heat exchanger, which makes the air and the refrigerant exchange heat; a second heat exchanger, which makes the water and the refrigerant exchange heat; a conversion valve, which delivers the refrigerant discharged from the compressor to the first heat exchanger or the second heat exchanger; a first liquid pipe, which connects the first heat exchanger and the second heat exchanger; a second liquid pipe, which is connected in parallel with the first liquid pipe, and connects the first heat exchanger and the second heat exchanger; a first expansion valve, which is arranged in the first liquid pipe and expands the flowing refrigerant; and a second expansion valve, which is arranged in the second liquid pipe and expands the flowing refrigerant; the caliber of the second expansion valve can be formed to be larger than the caliber of the first expansion valve. Therefore, the flow rate of the refrigerant can be adjusted according to the operation mode.

[0013] The heat supply device can operate in a cooling mode in which the refrigerant discharged from the compressor is delivered to the first heat exchanger, or in a heating mode in which the refrigerant discharged from the compressor is delivered to the second heat exchanger. In the cooling mode and the heating mode, the first liquid pipe and the second liquid pipe can be selectively opened to adjust the flow rate of the refrigerant according to the operating mode.

[0014] In the cooling mode, the second expansion valve can open the second liquid pipe and the first expansion valve can close the first liquid pipe, so that when the refrigerant discharged from the compressor flows to the first heat exchanger with a larger capacity, the second expansion valve with a larger diameter can be opened.

[0015] In the heating mode, the first expansion valve can open the first liquid pipe and the second expansion valve can close the second liquid pipe, so that when the refrigerant discharged from the compressor flows to the second heat exchanger with a relatively small capacity, the first expansion valve with a smaller diameter can be opened.

[0016] A pump for causing the water to flow into the second heat exchanger may be further included; when both the first liquid pipe and the second liquid pipe are opened, the operation of the pump may be interrupted to minimize heat exchange of the refrigerant in the second heat exchanger.

[0017] When the temperature of the first heat exchanger is lower than a first set temperature, the switching valve may be adjusted so that the refrigerant discharged from the compressor flows to the first heat exchanger, and the first expansion valve may be opened to perform a defrosting operation.

[0018] When the temperature of the first heat exchanger is lower than a first set temperature, the operation of the heat exchanger fan for forming an air flow toward the first heat exchanger may be stopped to perform a defrosting operation.

[0019] It may also include a temperature sensor for detecting the temperature of water flowing into the second heat exchanger; when the temperature of water flowing into the second heat exchanger is below a second set temperature, the switching valve can be adjusted so that the refrigerant discharged from the compressor flows to the second heat exchanger, and the first expansion valve and the second expansion valve can be fully opened to prevent the water in the second heat exchanger from being cooled while the first heat exchanger is defrosted.

[0020] When the temperature of the water flowing into the second heat exchanger is lower than the second set temperature, the water in the second heat exchanger may be prevented from being cooled by stopping the operation of the pump that supplies water to the second heat exchanger.

[0021] When the temperature of the water flowing into the second heat exchanger is lower than the second set temperature, the first heat exchanger may be defrosted by stopping the operation of the heat exchanger fan that generates air flow to the first heat exchanger.

[0022] The flow rate of the refrigerant flowing through the second expansion valve may be formed to be 1.2 to 2 times the flow rate of the refrigerant flowing through the first expansion valve, thereby coping with a change in the flowing refrigerant.

[0023] The control method of the heat supply device of the present invention may include: a step of detecting the temperature of a first heat exchanger that performs heat exchange between air and refrigerant; a step of detecting the temperature of water flowing into a second heat exchanger that performs heat exchange between water and refrigerant; and a step of performing a first defrosting operation mode that delivers the refrigerant discharged from the compressor to the first heat exchanger or a second defrosting operation mode that delivers the refrigerant discharged from the compressor to the second heat exchanger based on the temperature detected in the first heat exchanger and the temperature detected in the second heat exchanger. Therefore, the defrosting mode can be changed based on the temperature of the first heat exchanger and the temperature of the water flowing into the second heat exchanger.

[0024] When the temperature detected in the first heat exchanger is below the first set temperature and the temperature of the water flowing into the second heat exchanger is below the second set temperature, the second defrosting operation mode can be performed by adjusting the switching valve so that the refrigerant discharged from the compressor flows to the second heat exchanger. Therefore, when the water temperature is below a specified level, the first heat exchanger can be defrosted while preventing the water in the second heat exchanger from being cooled.

[0025] The method may include adjusting the first expansion valve and the second expansion valve respectively disposed in the first liquid pipe and the second liquid pipe connecting the first heat exchanger and the second heat exchanger in parallel to open the first liquid pipe and the second liquid pipe when the second defrosting operation mode is performed, so as to increase the flow rate of the refrigerant flowing from the second heat exchanger to the first heat exchanger.

[0026] The method may include stopping the operation of a pump supplying water to the second heat exchanger and stopping the operation of a heat exchanger fan for forming an air flow to the first heat exchanger when the second defrosting operation mode is performed. Therefore, the second defrosting operation mode can be terminated under a specified condition.

[0027] The step of terminating the second defrost operation mode by determining whether a release condition of the second defrost operation mode is satisfied may be included; determining whether the release condition is satisfied based on an outlet side temperature of the first heat exchanger along a direction of refrigerant flowing in the first heat exchanger.

[0028] The method may include the steps of adjusting the switching valve so that the refrigerant discharged from the compressor flows to the first heat exchanger when the temperature detected in the first heat exchanger is below the first set temperature and the temperature of the water flowing into the second heat exchanger exceeds the second set temperature, and performing the first defrosting operation mode, and stopping the operation of the heat exchanger fan that forms air flow to the first heat exchanger when the first defrosting operation mode is performed. Therefore, when the water flowing into the second heat exchanger is not at a low temperature of a predetermined degree, only the first heat exchanger is defrosted.

[0029] The method may include adjusting the first expansion valve and the second expansion valve, which are respectively arranged on the first liquid pipe and the second liquid pipe connecting the first heat exchanger and the second heat exchanger in parallel, to open only one of the first liquid pipe and the second liquid pipe when the first defrosting operation mode is performed. Since the defrosting operation is often performed during the heating operation, the first expansion valve and the second expansion valve may be adjusted in conjunction with the heating operation.

[0030] The heat supply device of the present invention may include: a compressor that compresses refrigerant; a first heat exchanger that exchanges heat between air and refrigerant; a second heat exchanger that exchanges heat between water and refrigerant; a pump that supplies water to the second heat exchanger; a heat exchanger fan that forms air flow to the first heat exchanger; a switching valve that delivers the refrigerant discharged from the compressor to the first heat exchanger or the second heat exchanger; a first liquid pipe that connects the first heat exchanger and the second heat exchanger; a second liquid pipe that is connected in parallel with the first liquid pipe and connects the first heat exchanger and the second heat exchanger; a first expansion valve that is arranged in the first liquid pipe and expands the flowing refrigerant; and a second expansion valve that is arranged in the second liquid pipe and expands the flowing refrigerant; when the temperature of water flowing into the second heat exchanger is below a set temperature, the first expansion valve and the second expansion valve are adjusted so that the refrigerant discharged from the compressor flows from the second heat exchanger to the first heat exchanger, and the refrigerant flowing from the second heat exchanger to the first heat exchanger flows in the first liquid pipe and the second liquid pipe, respectively. Therefore, both the second heat exchanger and the first heat exchanger can be defrosted according to the temperature conditions.

[0031] When the temperature of water flowing into the second heat exchanger is lower than a set temperature, the operation of a pump supplying water to the second heat exchanger may be stopped.

[0032] Details of other embodiments are included in the detailed description and accompanying drawings.

[0033] According to the heat supply device of the present invention, one or more of the following effects can be achieved.

[0034] First, by arranging two expansion valves having different diameters in parallel and selectively opening and closing them according to the operation mode, there is an advantage that the refrigerant flow rate can be adjusted even when two heat exchangers having different capacities are used.

[0035] Secondly, there is also an advantage that the heat supply device can be operated in a plurality of operation modes by using the expansion valves respectively arranged in the liquid pipes connected in parallel.

[0036] Thirdly, there is also an advantage that the water flowing into the second heat exchanger can be prevented from being cooled in an extremely low temperature environment and the first heat exchanger can be defrosted.

[0037] The effects of the present invention are not limited to the above-mentioned effects, and those skilled in the art can clearly understand other effects not mentioned through the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 4 is a system diagram of a heat supply device according to an embodiment of the present invention.

[0039] Figure 2 This is a diagram for explaining the flow of refrigerant in a heating operation mode of a heat supply device according to an embodiment of the present invention.

[0040] Figure 3 This is a diagram for explaining the flow of refrigerant in the cooling operation mode of the heat supply device according to one embodiment of the present invention.

[0041] Figure 4 This is a diagram for explaining the flow of refrigerant in the first defrosting operation mode of the heat supply device according to one embodiment of the present invention.

[0042] Figure 5 This is a diagram for explaining the flow of refrigerant in the second defrosting operation mode of the heat supply device according to one embodiment of the present invention.

[0043] Figure 6 It is a system diagram of a heat supply device according to a first comparative example of the present invention.

[0044] Figure 7 It is a system diagram of a heat supply device according to a second comparative example of the present invention.

[0045] Figure 8 This is a diagram showing data measured during the second defrosting operation mode performed by the heat supply device of the present invention.

[0046] Fig. 9 This is a diagram showing data measured when the heat supply device according to the first comparative example of the present invention performs the second defrosting operation mode.

[0047] Fig.10 This is a diagram showing data measured when the heat supply device according to the second comparative example of the present invention performs the second defrosting operation mode.

[0048] Fig.11 1 is a flowchart showing a control method of a heat supply device according to the present invention.

[0049] Description of Reference Numerals

[0050] 10: Compressor

[0051] 12: Switching valve

[0052] 20: First heat exchanger

[0053] 22: Heat exchanger fan

[0054] 24: Second heat exchanger

[0055] 32: First liquid pipe

[0056] 34: Second liquid pipe

[0057] 40: First expansion valve

[0058] 42: Second expansion valve DETAILED DESCRIPTION

[0059] If with the attached Figure 1 The advantages and features of the present invention and the methods for achieving them will become clear by referring to the following embodiments described in detail. However, the present invention is not limited to the embodiments disclosed below and can be implemented in various forms that are different from each other. This embodiment is only provided to fully disclose the present invention and to fully disclose the scope of the invention to ordinary technicians in the field of technology, and the present invention is defined by the scope of the claims. Throughout the specification, the same reference numerals represent the same components.

[0060] Hereinafter, the present invention will be described with reference to the accompanying drawings for explaining a heat supply device according to an embodiment of the present invention.

[0061] The heat supply device described in the present invention can supply heat or cold energy to the indoor space. The heat supply device can supply heat or cold energy to the second heat exchanger 24 (see Figure 1 ) supplies high-pressure refrigerant or low-pressure refrigerant to supply heat energy or cold energy to the water flowing into the indoor space.

[0062] Below, refer to Figure 1 , the structure of the outdoor unit configured in the heat supply device is explained.

[0063] The heat supply device includes: a compressor 10 for compressing refrigerant; a first heat exchanger 20 for exchanging heat between the refrigerant discharged from the compressor 10 and air; a second heat exchanger 24 for exchanging heat between the refrigerant discharged from the compressor 10 and water; and a switching valve 12 for transferring the refrigerant discharged from the compressor 10 to the first heat exchanger 20 or the second heat exchanger 24. The heat supply device also includes a heat exchanger fan 22 for forming an air flow toward the first heat exchanger 20.

[0064] The first heat exchanger 20 performs heat exchange between air and refrigerant. Figure 1The first heat exchanger 20 may include: a plurality of branch refrigerant tubes 21a; a heat exchanger head 21b connecting one side of the plurality of branch refrigerant tubes 21a and a liquid pipe 30 described below; and a manifold 21c connecting the other side of the plurality of branch refrigerant tubes 21a and a gas pipe 18b.

[0065] The heat exchanger fan 22 may form an air flow toward the first heat exchanger 20. Therefore, when the heat exchanger fan 22 is operated, the air flow rate may increase, thereby changing the phase of the refrigerant flowing inside.

[0066] The second heat exchanger 24 exchanges heat between water and refrigerant. A plate-shaped heat exchanger may be used for the second heat exchanger 24. A flow path for water to flow and a flow path for refrigerant to flow are formed inside the second heat exchanger 24. The second heat exchanger 24 may change the phase of the refrigerant by exchanging heat between the refrigerant and water flowing inside.

[0067] The water flowing into the second heat exchanger 24 can flow by a pump (not shown) arranged on one side.

[0068] The switching valve 12 can transfer the refrigerant discharged from the compressor 10 to the first heat exchanger 20 or the second heat exchanger 24. The switching valve 12 can change the flow direction of the refrigerant discharged from the compressor 10 when the operation mode of the heat supply device is changed.

[0069] The heat supply device includes an accumulator 14 that separates the refrigerant flowing toward the compressor 10 and delivers the gas-phase refrigerant to the compressor 10. The heat supply device includes a muffler 16 for reducing the noise of the refrigerant discharged from the compressor 10.

[0070] The heat supply device includes a liquid pipe 30 connecting the first heat exchanger 20 and the second heat exchanger 24 .

[0071] The heat supply device includes a first expansion valve 40 that expands the refrigerant flowing from the second heat exchanger 24 to the first heat exchanger 20. The heat supply device includes a second expansion valve 42 that expands the refrigerant flowing from the first heat exchanger 20 to the second heat exchanger 24.

[0072] The liquid pipe 30 includes a first liquid pipe 32 in which the first expansion valve 40 is arranged and a second liquid pipe 34 in which the second expansion valve 42 is arranged.

[0073] The first liquid pipe 32 connects the first heat exchanger 20 and the second heat exchanger 24. The first liquid pipe 32 is provided with a first expansion valve 40.

[0074] Both ends of the second liquid pipe 34 are connected to the first liquid pipe 32 .

[0075] The caliber of the second expansion valve 42 is formed to be larger than the caliber of the first expansion valve 40. Here, the caliber of the expansion valve may refer to the size of the internal orifice formed when the expansion valve is opened to the maximum. The flow rate of the flow may be different depending on the caliber of the expansion valve. Therefore, when the second expansion valve 42 having a relatively large caliber is opened, the flow rate of the refrigerant flowing in the first liquid pipe 32 or the second liquid pipe 34 may be increased compared to when the first expansion valve 40 is opened.

[0076] The diameter of the second liquid pipe 34 may be formed to be larger than the diameter of the first liquid pipe 32 .

[0077] The heat supply device may include: a high-pressure pipe 18 a through which the refrigerant discharged from the compressor 10 flows; a first air pipe 18 b connecting the switching valve 12 and the first heat exchanger 20 ; and a second air pipe 18 c connecting the switching valve 12 and the second heat exchanger 24 .

[0078] <Operation>

[0079] Below, refer to Figure 2 and Figure 5 Flows of the refrigerant and states of each configuration in the heating operation mode HM, the cooling operation mode CM, the first defrosting operation mode DM1, and the second defrosting operation mode DM2 of the heat supply device will be described.

[0080] The heat supply device of the present invention can be operated in the heating operation mode HM or the cooling operation mode CM. The heat supply device of the present invention can also be operated in the first defrosting operation mode DM1 or the second defrosting operation mode DM2.

[0081] The heating operation mode HM is an operation method for heating water flowing in the second heat exchanger 24 by sending high-pressure refrigerant to the second heat exchanger 24. The cooling operation mode CM is an operation method for cooling water flowing in the second heat exchanger 24 by sending high-pressure refrigerant to the first heat exchanger 20.

[0082] The first defrost operation mode DM1 is an operation method for heating the first heat exchanger 20 by sending a high-pressure refrigerant to the first heat exchanger 20. Frost or the like generated on the first heat exchanger 20 can be removed by the first defrost operation mode DM1.

[0083] The second defrost operation mode DM2 is an operation method for heating the second heat exchanger 24 by sending a high-pressure refrigerant to the heat exchanger 24. The water in the second heat exchanger 24 can be heated in the second defrost operation mode DM2.

[0084] Reference Figure 2In the heating operation mode HM, the switching valve 12 delivers the refrigerant discharged from the compressor 10 to the second heat exchanger 24. In the heating operation mode HM, the first expansion valve 40 is adjusted to expand the refrigerant flowing in the first liquid pipe 32. In the heating operation mode HM, the second expansion valve 42 is adjusted so that the refrigerant does not flow to the second liquid pipe 34.

[0085] In the heating operation mode HM, the first heat exchanger 20 functions as an evaporator. In the heating operation mode HM, the second heat exchanger 24 functions as a condenser.

[0086] Reference Figure 2 , the refrigerant discharged from the compressor 10 can flow to the second heat exchanger 24 and heat the water. The refrigerant flowing from the second heat exchanger 24 flows along the first liquid pipe 32. The refrigerant flowing along the first liquid pipe 32 can be expanded by the first expansion valve 40. The refrigerant passing through the first expansion valve 40 can flow to the first heat exchanger 20 and perform heat exchange with the air.

[0087] The refrigerant flowing from the first heat exchanger 20 may pass through the switching valve 12 and the accumulator 14 and flow toward the compressor 10 .

[0088] In the heating operation mode HM, the refrigerant may heat the water flowing in the second heat exchanger 24. In addition, in the heating operation mode HM, the refrigerant flowing from the second heat exchanger 24 may flow toward the first heat exchanger 20 after being expanded by the first expansion valve 40. Since the second expansion valve 42 closes the second liquid pipe 34, the refrigerant does not flow toward the second liquid pipe 34.

[0089] Reference Figure 3 In the cooling operation mode CM, the switching valve 12 delivers the refrigerant discharged from the compressor 10 to the first heat exchanger 20. In the cooling operation mode CM, the second expansion valve 42 is adjusted to expand the refrigerant flowing in the second liquid pipe 34. In the cooling operation mode CM, the first expansion valve 40 is adjusted so that the refrigerant does not flow to the first liquid pipe 32.

[0090] In the cooling operation mode CM, the first heat exchanger 20 functions as a condenser. In the cooling operation mode CM, the second heat exchanger 24 functions as an evaporator.

[0091] Reference Figure 3 The refrigerant discharged from the compressor 10 may flow to the first heat exchanger 20 to heat the air, and cool the water flowing in the second heat exchanger 24 .

[0092] The refrigerant flowing in the second liquid pipe 34 may be expanded by the second expansion valve 42. The refrigerant passing through the second expansion valve 42 may flow to the second heat exchanger 24 and perform heat exchange with water.

[0093] The refrigerant flowing from the second heat exchanger 24 may pass through the switching valve 12 and the accumulator 14 and flow toward the compressor 10 .

[0094] In the cooling operation mode CM, the refrigerant may cool the water flowing in the second heat exchanger 24. In the cooling operation mode CM, the refrigerant flowing from the first heat exchanger 20 may expand through the second expansion valve 42 and flow toward the second heat exchanger 24. Since the first expansion valve 40 closes the first liquid pipe 32, the refrigerant does not flow toward the first liquid pipe 32.

[0095] Reference Figure 2 and Figure 3 In the cooling operation mode CM, the refrigerant discharged from the compressor 10 flows to the first heat exchanger 20 for heat exchange between air and the refrigerant. In the heating operation mode HM, the refrigerant discharged from the compressor 10 flows to the second heat exchanger 24 for heat exchange between water and the refrigerant.

[0096] Since the first heat exchanger 20 exchanges heat between air and refrigerant, the refrigerant flows through the plurality of branch refrigerant pipes 21a. That is, the first heat exchanger 20 has a larger flow area for the refrigerant flow than the second heat exchanger 24. Therefore, when the refrigerant discharged from the compressor 10 flows to the first heat exchanger 20, a relatively large amount of refrigerant is required.

[0097] In the present invention, the amount of refrigerant flowing in the cooling operation mode CM is increased by forming the diameter of the second expansion valve 42 to be larger than the diameter of the first expansion valve 40 .

[0098] That is, Figure 2 As shown, in the heating operation mode HM, the refrigerant discharged from the second heat exchanger 24 can flow to the first heat exchanger 20 through the first expansion valve 40, thereby reducing the amount of refrigerant; in the cooling operation mode CM, the refrigerant discharged from the first heat exchanger 20 can flow to the second heat exchanger 24 through the second expansion valve 42, thereby increasing the amount of refrigerant.

[0099] Below, refer to Figure 4 and Figure 5 , the defrost operation mode is explained.

[0100] The heat supply device of the present invention may include a first defrost operation mode DM1 in which the refrigerant discharged from the compressor 10 is delivered to the first heat exchanger 20 , and a second defrost operation mode DM2 in which the refrigerant discharged from the compressor 10 is delivered to the first heat exchanger 20 via the second heat exchanger 24 .

[0101] First, refer to Figure 4 , the first defrosting operation mode DM1 will be described.

[0102] Reference Figure 4 In the first defrost operation mode DM1, the switching valve 12 delivers the refrigerant discharged from the compressor 10 to the first heat exchanger 20. In the first defrost operation mode DM1, since the high-temperature and high-pressure refrigerant discharged from the compressor 10 can be directly supplied to the first heat exchanger 20, frost and the like formed on the first heat exchanger 20 can be removed.

[0103] In the first defrost operation mode DM1, the first expansion valve 40 is adjusted so that the refrigerant flowing in the first liquid pipe 32 expands. In the first defrost operation mode DM1, the second expansion valve 42 is adjusted so that the refrigerant does not flow into the second liquid pipe 34. Since the first defrost operation mode DM1 is often performed during the heating operation mode HM, the first expansion valve 40 opened in the heating operation mode HM can be kept open.

[0104] In the first defrost operation mode DM1 , the heat exchanger fan 22 is not operated. In the first defrost operation mode DM1 , a pump (not shown) may be operated to allow water to flow to the second heat exchanger 24 .

[0105] Below, refer to Figure 5 , the second defrosting operation mode DM2 will be described.

[0106] In the second defrost operation mode DM2 , frost or the like formed on the first heat exchanger 20 can be removed while preventing a decrease in the temperature of water flowing to the second heat exchanger 24 by utilizing the refrigerant discharged from the compressor 10 .

[0107] Reference Figure 5 In the second defrosting operation mode DM2 , the switching valve 12 transfers the refrigerant discharged from the compressor 10 to the second heat exchanger 24 . In the second defrosting operation mode DM2 , the operation of the pump is stopped. Therefore, the refrigerant discharged from the compressor 10 can flow to the first heat exchanger 20 through the second heat exchanger 24 .

[0108] The refrigerant discharged from the compressor 10 and flowing to the first heat exchanger 20 through the second heat exchanger 24 may have a temperature of the refrigerant supplied to the first heat exchanger 20 that is lower than a predetermined level as it generates a pressure loss through the liquid pipe 30. When the temperature of the refrigerant supplied to the first heat exchanger 20 is lower than a predetermined level, frost or the like formed on the first heat exchanger 20 cannot be removed. Therefore, the refrigerant flowing from the second heat exchanger 24 to the first heat exchanger 20 flows through the first liquid pipe 32 and the second liquid pipe 34 to reduce the pressure loss generated in the refrigerant flowing in the liquid pipe 30. That is, the refrigerant flowing from the second heat exchanger 24 to the first heat exchanger 20 flows through the wide areas of the first liquid pipe 32 and the second liquid pipe 34 and flows to the first expansion valve 40 and the second expansion valve 42, respectively, so that the pressure loss can be improved. Therefore, the temperature of the refrigerant supplied to the first heat exchanger 20 can be higher than a predetermined level.

[0109] Thereafter, the first heat exchanger 20 may be defrosted by the refrigerant flowing in the first heat exchanger 20 .

[0110] The heat supply device of the present invention is more effective in the second defrosting operation than heat supply devices having other structures.

[0111] That is, compared with Figure 6 A heat supply device of a first comparative example having a structure of Figure 7 The heat supply device of the second comparative example with the structure can improve the performance of the second defrost operation mode DM2.

[0112] First, briefly explain Figure 6 Heat supply device and Figure 7 The heat supply device is composed of Figures 8 to 10 The data are used to confirm the effect of the heat supply device of the present invention.

[0113] Reference Figure 6 The heat supply device of the first comparative example has Figure 1 However, there is only one liquid pipe 30 and one expansion valve 40 disposed on the liquid pipe 30 between the first heat exchanger 20 and the second heat exchanger 24 .

[0114] The heat supply device of the first comparative example can be operated in the heating operation mode HM or the cooling operation mode CM by opening only the same expansion valve 40. In this case, there is no difference in the amount of refrigerant in the heating operation mode HM or the cooling operation mode CM.

[0115] In addition, when the second defrosting operation mode DM2 of the present invention is executed, the refrigerant passing through the second heat exchanger 24 passes through only one liquid pipe 30 and one expansion valve 40, so a large pressure loss occurs. This causes the temperature of the refrigerant supplied to the first heat exchanger 20 to become below zero, and the defrosting of the first heat exchanger 20 cannot be performed.

[0116] Reference Figure 7 The heat supply device of the second comparative example is different from the heat supply device of the first comparative example in that a hot gas pipe 50 and a hot gas valve 52 are additionally arranged. The hot gas pipe 50 connects the high pressure pipe 18a and the liquid pipe 30. The hot gas valve 52 can be arranged on the hot gas pipe 50 to open and close the hot gas pipe 50.

[0117] The heat supply device of the second comparative example can transport the refrigerant discharged from the compressor 10 to the first heat exchanger 20 in the first defrost operation mode DM1 like the heat supply device of the present invention, and the refrigerant discharged from the first heat exchanger 20 can flow to the compressor 10 via the second heat exchanger 24 through the liquid pipe 30 and the expansion valve 40.

[0118] Furthermore, the heat supply device of the second comparative example may send the refrigerant discharged from the compressor 10 to the second heat exchanger 24 and send part of the refrigerant discharged from the compressor 10 to the hot gas pipe 50 in the second defrost operation mode DM2 .

[0119] Therefore, as the refrigerant flowing from the first heat exchanger 20 to the second heat exchanger 24 flows through the liquid pipe 30 and the expansion valve 40, pressure loss may occur, but it can merge with the high-temperature and high-pressure refrigerant flowing to the hot gas pipe 50 and flow to the first heat exchanger 20. This can prevent the refrigerant flowing to the first heat exchanger 20 from becoming less than a predetermined level.

[0120] Reference Figures 8 to 10 It is possible to confirm the temperature and pressure of each structure of the heat supply device of the present invention and the heat supply devices of the first comparative example and the second comparative example when the second defrosting operation mode DM2 is executed.

[0121] Reference Figure 8 When the heat supply device of the present invention drives the compressor 10, it can be confirmed that the discharge pressure and discharge temperature of the compressor 10 increase. In addition, when the compressor 10 is driven, it can be confirmed that the temperature of the refrigerant flowing into the first heat exchanger 20 is formed to be above zero degrees Celsius and gradually increases. In addition, it can be confirmed that the temperature of the refrigerant discharged from the first heat exchanger 20 is formed to be above minus ten degrees Celsius and gradually increases.

[0122] Therefore, the inlet temperature of the refrigerant flowing through the first heat exchanger 20 gradually increases from zero degrees Celsius or more, thereby defrosting the first heat exchanger 20. In addition, the discharge temperature and discharge pressure of the compressor 10 can be increased to shorten the time of the second defrosting operation mode DM2.

[0123] On the contrary, refer to Fig. 9 In the heat supply device of the first comparative example, the temperature of the refrigerant flowing into the first heat exchanger 20 is formed to be lower than zero degrees Celsius, and the problem of being unable to defrost the first heat exchanger 20 occurs. That is, since the pressure loss generated in the liquid pipe 30 and the expansion valve 40 is too large, it can be confirmed that the temperature of the refrigerant detected at the inlet side of the first heat exchanger 20 is formed to be less than minus ten degrees Celsius.

[0124] In addition, refer to Fig.10 In the heat supply device of the second comparative example, it can be confirmed that the temperature of the refrigerant flowing into the first heat exchanger 20 is formed to be above zero degrees Celsius and gradually increases to be above ten degrees Celsius. In addition, although the temperature of the refrigerant discharged from the first heat exchanger 20 is also formed to be below zero degrees Celsius in the initial stage, it can be confirmed that the temperature gradually increases and rises to above zero degrees Celsius as the compressor 10 operates.

[0125] However, it can be confirmed that in the heat supply device of the second comparative example, the temperature and pressure of the refrigerant discharged from the compressor are lower than those of the heat supply device of the present invention. Figure 8 In the heat supply device of the present invention, it can be confirmed that the average pressure of the refrigerant discharged from the compressor 10 is above 1800 kPa, but in the heat supply device of the second comparative example, it can be confirmed that the average pressure of the refrigerant discharged from the compressor 10 is formed to be 900 kPa.

[0126] Therefore, it can be confirmed that the operation time of the second defrost operation mode DM2 in the heat supply device of the present invention is shorter than the operation time of the second defrost operation mode DM2 in the heat supply device of the second comparative example.

[0127] <Control>

[0128] Below, refer to Fig.11 , describing the control method of the heat supply device of the present invention.

[0129] First, step S100 of detecting the temperature of the first heat exchanger 20 and step S110 of detecting the temperature of the second heat exchanger 24 are performed. Step S100 of detecting the temperature of the first heat exchanger 20 and step S110 of detecting the temperature of the second heat exchanger 24 may be performed during the heating operation mode HM. In addition, step S100 of detecting the temperature of the first heat exchanger 20 and step S110 of detecting the temperature of the second heat exchanger 24 may be performed at the beginning of the heating operation mode HM.

[0130] The step S100 of detecting the temperature of the first heat exchanger 20 may be detected based on the discharge pressure of the compressor 10 and the suction pressure of the compressor 10. The step S100 of detecting the temperature of the first heat exchanger 20 may also be detected by an additional temperature sensor (not shown).

[0131] The step S110 of detecting the temperature of the second heat exchanger 24 may detect the temperature of water flowing into the second heat exchanger 24. The step S110 of detecting the temperature of the second heat exchanger 24 may also be detected by an additional temperature sensor (not shown).

[0132] Thereafter, step S120 of determining whether the defrosting operation mode entry condition is satisfied is performed. Step S120 of determining whether the defrosting operation mode entry condition is satisfied may be determined based on the temperature of the first heat exchanger 20 .

[0133] The step S120 of judging whether the defrost operation mode entry condition is satisfied can be judged based on whether the temperature of the first heat exchanger 20 is below the first set temperature. That is, when the temperature of the first heat exchanger 20 is below the first set temperature, it can be judged that the defrost operation mode entry condition is satisfied. However, when the temperature of the first heat exchanger 20 exceeds the first set temperature, since the defrost operation mode entry condition is not satisfied, the step S100 of detecting the temperature of the first heat exchanger 20 and the step S110 of detecting the temperature of the second heat exchanger 24 can be continuously performed.

[0134] When it is determined that the defrosting operation mode entry condition is satisfied, the first defrosting operation mode DM1 or the second defrosting operation mode DM2 can be performed. Therefore, it is additionally determined whether the second defrosting operation mode DM2 entry condition is satisfied (S130).

[0135] The step S130 of determining whether the second defrost operation mode DM2 entry condition is satisfied may be determined based on the temperature of water flowing into the second heat exchanger 24. When the temperature of water flowing into the second heat exchanger 24 is lower than the second set temperature, it may be determined that the second defrost operation mode DM2 entry condition is satisfied.

[0136] When the temperature flowing into the second heat exchanger 24 is lower than the second set temperature, in the case of the first defrost operation mode DM1, the temperature of the water discharged from the second heat exchanger 24 is too low, so the pipe for supplying water may freeze and crack. Therefore, when the temperature flowing into the second heat exchanger 24 is lower than the second set temperature, it is determined that the entry condition of the second defrost operation mode DM2 is met, so that the second defrost operation mode DM2 can be performed.

[0137] Based on the temperature detected at the first heat exchanger 20 and the temperature detected at the second heat exchanger 24 , a first defrost operation mode DM1 in which the refrigerant discharged from the compressor 10 is sent to the first heat exchanger 20 or a second defrost operation mode DM2 in which the refrigerant is sent to the second heat exchanger 24 may be performed.

[0138] If the second defrosting operation mode DM2 is performed, step S200 of adjusting the switching valve 12 is performed. If the second defrosting operation mode DM2 is performed, the switching valve 12 is adjusted so that the refrigerant discharged from the compressor 10 flows to the second heat exchanger 24. However, when the heating operation mode HM is operated, the switching valve 12 may be adjusted to keep the refrigerant discharged from the compressor 10 flowing to the second heat exchanger 24.

[0139] If the second defrosting operation mode DM2 is performed, a step S210 of stopping the operation of a pump (not shown) is performed. Therefore, heat exchange between the refrigerant and water flowing in the second heat exchanger 24 can be minimized.

[0140] In addition, step S220 of stopping the operation of the heat exchanger fan 22 disposed on the first heat exchanger 20 side is performed.

[0141] If the second defrosting operation mode DM2 is performed, step S230 is performed to open the first expansion valve 40 and the second expansion valve 42. By opening the first expansion valve 40 and the second expansion valve 42, the refrigerant flows to the first liquid pipe 32 and the second liquid pipe 34. Therefore, the pressure loss generated when the refrigerant flows from the second heat exchanger 24 to the first heat exchanger 20 can be reduced.

[0142] As the second defrosting operation mode DM2 is performed, frost and the like generated on the first heat exchanger 20 can be removed.

[0143] Thereafter, step S240 is performed to determine whether the release condition of the second defrosting operation mode DM2 is satisfied.

[0144] The step S240 of determining whether the release condition of the second defrosting operation mode DM2 is satisfied may be determined based on the outlet side temperature of the first heat exchanger 20 along the direction of the refrigerant flowing in the first heat exchanger 20. During the second defrosting operation mode DM2, the outlet side of the first heat exchanger 20 may be an air pipe disposed between the first heat exchanger 20 and the compressor 10. Figure 5 During the second defrosting operation mode DM2, the outlet side of the first heat exchanger 20 may be a region where the first air pipe 18b is disposed.

[0145] The step S240 of determining whether the second defrosting operation mode DM2 release condition is satisfied may be determined based on the time elapsed after the second defrosting operation mode DM2 is performed.

[0146] The step S240 of judging whether the second defrost operation mode DM2 release condition is satisfied may be judged based on the outlet side temperature of the first heat exchanger 20 in the direction of the refrigerant flowing in the first heat exchanger 20 or the time elapsed after the second defrost operation mode DM2 is performed.

[0147] That is, when the temperature of the gas pipe connected to the first heat exchanger 20 is higher than the third set temperature or the time after the second defrosting operation mode DM2 is performed exceeds the first set time, it can be determined that the second defrosting operation mode DM2 release condition is satisfied.

[0148] When the second defrosting operation mode DM2 release condition is satisfied, the heating operation mode HM may be performed ( S400 ). However, when the second defrosting operation mode DM2 release condition is not satisfied, the second defrosting operation mode DM2 may be continuously performed.

[0149] When the second defrost operation mode DM2 entry condition is not satisfied, the first defrost operation mode DM1 may be performed.

[0150] When the first defrosting operation mode DM1 is performed, the step S300 of adjusting the switching valve 12 is performed. When the first defrosting operation mode DM1 is performed, the switching valve 12 is adjusted so that the refrigerant discharged from the compressor 10 flows to the first heat exchanger 20 .

[0151] When the heating operation mode HM is previously operated, the switching valve 12 is adjusted so that the refrigerant discharged from the compressor 10 and flowing to the second heat exchanger 24 flows to the first heat exchanger 20 .

[0152] If the first defrosting operation mode DM1 is performed, the operation of the pump can be maintained.

[0153] When the first defrosting operation mode DM1 is performed, step S310 is performed to stop the operation of the heat exchanger fan 22 disposed on the first heat exchanger 20 side.

[0154] If the first defrosting operation mode DM1 is performed, step S320 is performed to open the first expansion valve 40 and close the second expansion valve 42. Since the first defrosting operation mode DM1 can be performed during the heating operation mode HM, the first expansion valve 40 can be opened and the second expansion valve 42 can be closed in the heating operation mode HM.

[0155] As the first defrosting operation mode DM1 is performed, frost and the like generated on the first heat exchanger 20 can be removed.

[0156] Thereafter, step S330 is performed to determine whether the release condition of the first defrosting operation mode DM1 is satisfied.

[0157] The step S330 of determining whether the first defrosting operation mode DM1 release condition is satisfied may be determined based on the outlet side temperature of the first heat exchanger 20 in the direction of the refrigerant flowing in the first heat exchanger 20 .

[0158] During the first defrosting operation mode DM1, the outlet side of the first heat exchanger 20 may be a liquid pipe 30 disposed between the first heat exchanger 20 and the compressor 10. Figure 4 During the first defrosting operation mode DM1 , the outlet side of the first heat exchanger 20 may be a region where the liquid pipe 30 is disposed.

[0159] The step S330 of determining whether the first defrost operation mode DM1 release condition is satisfied may be determined based on the time elapsed after the first defrost operation mode DM1 is performed.

[0160] The step S330 of judging whether the first defrost operation mode DM1 release condition is satisfied may be judged based on an outlet side temperature of the first heat exchanger 20 in a direction of the refrigerant flowing in the first heat exchanger 20 or a time elapsed after the first defrost operation mode DM1 is performed.

[0161] That is, when the temperature of the liquid pipe connected to the first heat exchanger 20 is equal to or higher than the fourth set temperature or the time elapsed after the first defrosting operation mode DM1 is performed exceeds the second set time, it can be determined that the first defrosting operation mode DM1 release condition is satisfied.

[0162] When the first defrosting operation mode DM1 release condition is satisfied, the heating operation mode HM may be performed ( S400 ). However, when the first defrosting operation mode DM1 release condition is not satisfied, the first defrosting operation mode DM1 may be continuously performed.

[0163] Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-mentioned specific embodiments, and a person skilled in the art may make various modifications within the scope of the present invention as claimed in the claims, and these modifications should not be understood separately from the technical idea or prospect of the present invention.

Claims

1. A heat supply device, wherein: include: compressor, which compresses the refrigerant; A first heat exchanger for exchanging heat between air and refrigerant; A second heat exchanger for exchanging heat between water and refrigerant; a switching valve for delivering the refrigerant discharged from the compressor to the first heat exchanger or the second heat exchanger; a first liquid pipe, connecting the first heat exchanger and the second heat exchanger; a second liquid pipe connected in parallel with the first liquid pipe, connecting the first heat exchanger and the second heat exchanger; a first expansion valve disposed on the first liquid pipe and expanding the flowing refrigerant; as well as a second expansion valve disposed on the second liquid pipe and expanding the flowing refrigerant; The second expansion valve has a larger diameter than the first expansion valve.

2. The heat supply device according to claim 1, wherein: The heat supply device operates in a cooling mode in which the refrigerant discharged from the compressor is delivered to the first heat exchanger or in a heating mode in which the refrigerant discharged from the compressor is delivered to the second heat exchanger; In the cooling mode and the heating mode, the first liquid pipe and the second liquid pipe are selectively opened.

3. The heat supply device according to claim 2, wherein: In the cooling mode, the second expansion valve opens the second liquid pipe, and the first expansion valve closes the first liquid pipe.

4. The heat supply device according to claim 2, wherein: In the heating mode, the first expansion valve opens the first liquid pipe, and the second expansion valve closes the second liquid pipe.

5. The heat supply device according to claim 1, wherein: Also included is a pump that creates a flow of water into the second heat exchanger; When both the first liquid pipe and the second liquid pipe are opened, the operation of the pump is interrupted.

6. The heat supply device according to claim 1, wherein: When the temperature of the first heat exchanger is equal to or lower than a first set temperature, the switching valve is adjusted so that the refrigerant discharged from the compressor flows to the first heat exchanger and the first expansion valve is opened.

7. The heat supply device according to claim 6, wherein: When the temperature of the first heat exchanger is lower than a first set temperature, the operation of a heat exchanger fan for forming an air flow toward the first heat exchanger is stopped.

8. The heat supply device according to claim 1, wherein: Also comprising a temperature sensor for detecting the temperature of water flowing into the second heat exchanger; When the temperature of water flowing into the second heat exchanger is lower than a second set temperature, the switching valve is adjusted so that the refrigerant discharged from the compressor flows to the second heat exchanger and the first expansion valve and the second expansion valve are both opened.

9. The heat supply device according to claim 8, wherein: When the temperature of water flowing into the second heat exchanger is lower than or equal to a second set temperature, the operation of a pump that supplies water to the second heat exchanger is stopped.

10. The heat supply device according to claim 9, wherein: When the temperature of the water flowing into the second heat exchanger is lower than the second set temperature, the operation of the heat exchanger fan for forming the air flow toward the first heat exchanger is stopped.

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