Heat supply device

Abstract

The invention relates to a heat supply device. A heat supply device according to the present invention comprises: a compressor that compresses a refrigerant; a first heat exchanger which is connected to the compressor by means of a refrigerant pipe and which exchanges heat between the refrigerant and water; a second heat exchanger which is connected to the compressor by means of a refrigerant pipe and which exchanges heat between the refrigerant and air; a first expansion device disposed in a refrigerant pipe connecting the first heat exchanger and the second heat exchanger; the second expansion device is connected with the first expansion device in parallel and is opened and closed according to an electric signal; the control part is used for controlling the opening degree of the second expansion device; when the heating operation is started and the temperature of the water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger, the control unit can open the second expansion device.

Description

Technical Field

[0001] The present invention relates to a heat supply device, and more particularly to a heat supply device for performing heat exchange between water and a refrigerant for heating an indoor space. Background Art

[0002] The heating system including the gas boiler supplies the heat source heated by the gas boiler to the load part such as the floor heating or the hot water tank through the pipe. The pipe connecting the gas boiler and the load part can be arranged in a state of being buried in the building.

[0003] However, in various countries such as Europe, in order to reduce carbon generation and minimize the use of refrigerant, there is a trend to replace gas boilers with heat supply devices that utilize heat exchange between water and refrigerant.

[0004] The "cooling and heating device" disclosed in Korean Patent Publication No. 10-2022-0027562 includes: a compressor; a four-way valve; a first heat exchanger for heat exchange between water and refrigerant; a second heat exchanger for heat exchange between outdoor air and refrigerant; and an expansion valve arranged between the first heat exchanger and the second heat exchanger.

[0005] In the above-mentioned conventional cooling and heating device, at the initial stage of heating operation, the temperature of water flowing into the first heat exchanger is formed to be higher than the temperature of the refrigerant discharged from the compressor and flowing into the first heat exchanger, so there is a problem that the refrigerant cannot be smoothly condensed while passing through the first heat exchanger. In particular, in an AWHP (Air to Water Heat Pump) that performs heat exchange between water and refrigerant and uses the heat exchanged water to cool and heat the indoor space, the temperature of water flowing into the first heat exchanger can rise to more than 60 degrees, so there is a problem that the time for the temperature of the refrigerant flowing into the first heat exchanger to become lower than the temperature of the water flowing into the first heat exchanger is further prolonged.

[0006] If the temperature of the water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger, the refrigerant cannot be condensed while passing through the first heat exchanger, and moves to the expansion valve in a gas phase refrigerant state. The gas phase refrigerant has difficulty passing through the expansion valve smoothly, so there is a problem that the pressure of the low pressure part further decreases in the entire cycle. This may cause a malfunction of the compressor.

[0007] Prior art literature

[0008] Patent Literature

[0009] Korean Patent Publication No. 10-2022-0027562 (published on March 8, 2022) Summary of the invention

[0010] An object of the present invention is to provide a heat supply device having improved durability.

[0011] Another object of the present invention is to provide a heat supply device with improved low pressure drop phenomenon of a compressor.

[0012] Another object of the present invention is to provide a heat supply device for adjusting the flow path area of ​​an expansion device.

[0013] The objects of the present invention are not limited to the above-mentioned objects, and those skilled in the art can clearly understand other objects not mentioned from the following description.

[0014] According to one aspect of the present invention for achieving the above-mentioned purpose, the heat supply device includes: a compressor, which compresses refrigerant; a first heat exchanger, which is connected to the compressor by a refrigerant piping, so that the refrigerant and water are heat exchanged; a second heat exchanger, which is connected to the compressor by a refrigerant piping, so that the refrigerant and air are heat exchanged; a first expansion device, which is arranged on the refrigerant piping connecting the first heat exchanger and the second heat exchanger; a second expansion device, which is connected in parallel with the first expansion device and is opened and closed according to an electrical signal; and a control unit, which controls the opening degree of the second expansion device; if the heating operation is started and the temperature of the water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger, the control unit opens the second expansion device, thereby increasing the flow area of ​​the expansion device.

[0015] The control unit may open the second expansion device if the temperature of water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger by a predetermined temperature or more.

[0016] When opening the second expansion device, the control unit gradually opens the second expansion device with a predetermined pulse at a predetermined cycle, thereby reducing a rapidly changing load applied to the system.

[0017] If the temperature of water flowing into the first heat exchanger is greater than the temperature of the refrigerant flowing into the first heat exchanger and the evaporation temperature of the refrigerant flowing into the compressor is below a specified temperature, the control unit opens the second expansion device, thereby allowing the second expansion device to be opened when a low pressure drop phenomenon actually occurs.

[0018] If the temperature of water flowing into the first heat exchanger is greater than the temperature of the refrigerant flowing into the first heat exchanger and the difference between the evaporation temperature of the refrigerant flowing into the compressor and the temperature of the outdoor air is above a specified temperature, the control unit opens the second expansion device, thereby allowing the second expansion device to be opened when a low pressure drop phenomenon actually occurs.

[0019] If the temperature of water flowing into the first heat exchanger after the second expansion device is opened is lower than the temperature of the refrigerant flowing into the first heat exchanger, the control unit closes the second expansion device so that the flow area of ​​the expansion device can be restored to an initial state when the condensation condition of the refrigerant is formed.

[0020] When closing the second expansion device, the control unit gradually closes the second expansion device with a predetermined pulse at a predetermined cycle, thereby reducing a rapidly changing load applied to the system.

[0021] When opening the second expansion device, the control unit gradually opens the second expansion device with specified pulses in a specified period; the closing speed of the second expansion device is greater than the opening speed of the second expansion device, thereby minimizing the amount of liquid-phase refrigerant flowing into the compressor.

[0022] When the cooling operation starts, the control unit may close the second expansion device.

[0023] The open flow path area of ​​the second expansion device is larger than the flow path area of ​​the first expansion device, so that the opening degree of the second expansion device can be easily adjusted.

[0024] According to one aspect of the present invention for achieving the above-mentioned purpose, in a control method of a heat supply device, the heat supply device includes a compressor, a water-refrigerant heat exchanger, an air-refrigerant heat exchanger, a first expansion device arranged between the water-refrigerant heat exchanger and the air-refrigerant heat exchanger, and a second expansion device connected in parallel with the first expansion device, wherein the control method includes: when the refrigerant discharged from the compressor flows into the water-refrigerant heat exchanger, a step of sensing the temperatures of the refrigerant and water flowing into the water-refrigerant heat exchanger; and if the temperature of the water flowing into the water-refrigerant heat exchanger is greater than the temperature of the refrigerant flowing into the water-refrigerant heat exchanger, a step of opening the second expansion device, thereby increasing the flow area of ​​the expansion device.

[0025] In the step of opening the second expansion device, the second expansion device is gradually opened with a prescribed pulse at a prescribed cycle, thereby being able to reduce a rapidly changing load applied to the system.

[0026] Between the step of sensing the temperature of the water-refrigerant heat exchanger and the step of opening the second expansion device, it also includes: a step of measuring the low pressure of the compressor and determining whether the low pressure of the compressor is below a specified pressure; the step of opening the second expansion device is performed when the low pressure of the compressor is below the specified pressure, so that the second expansion device can be opened when a low pressure drop actually occurs.

[0027] In the step of judging whether the low pressure of the compressor is below the specified pressure, when the evaporation temperature of the measured low-pressure refrigerant is below the specified temperature, it is judged that the low pressure of the compressor is below the specified pressure, thereby judging whether a low pressure drop phenomenon has actually occurred through the evaporation temperature of the refrigerant flowing into the compressor, and the second expansion device can be opened.

[0028] In the step of judging whether the low pressure of the compressor is below the specified pressure, when the difference between the measured evaporation temperature of the low-pressure refrigerant and the temperature of the outdoor air is above the specified temperature value, it is judged that the low pressure of the compressor is below the specified pressure, thereby judging whether the low pressure drop phenomenon has actually occurred through the difference between the evaporation temperature of the refrigerant flowing into the compressor and the temperature of the outdoor air, and the second expansion device can be opened.

[0029] The control method includes: when the refrigerant discharged from the compressor flows into the air-refrigerant heat exchanger or the refrigerant discharged from the compressor flows into the water-refrigerant heat exchanger, if the temperature of the water flowing into the water-refrigerant heat exchanger is lower than the temperature of the refrigerant flowing into the water-refrigerant heat exchanger, the step of closing the second expansion device, so that the second expansion device can be closed when the initial condensation condition is formed when the refrigerant is in a cooling operation state or a heating operation.

[0030] After the step of opening the second expansion device, the steps include: a step of sensing the temperatures of the refrigerant and water flowing into the water-refrigerant heat exchanger; and a step of closing the second expansion device if the temperature of the water flowing into the water-refrigerant heat exchanger is lower than the temperature of the refrigerant flowing into the water-refrigerant heat exchanger, so that if a condensation condition is formed after opening the second expansion device, the second expansion device can be closed.

[0031] In the step of closing the second expansion device, the second expansion device is gradually closed with a prescribed pulse at a prescribed period, thereby being able to reduce a rapidly changing load applied to the system.

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

[0033] According to at least one embodiment of the present invention, since the second expansion device is connected in parallel with the first expansion device and is opened when the temperature of water flowing into the first heat exchanger after the heating operation starts is higher than the temperature of the refrigerant flowing into the first heat exchanger, the outdoor unit can circulate smoothly even when the refrigerant discharged from the compressor is not condensed in the first heat exchanger.

[0034] According to at least one embodiment of the present invention, since the second expansion device is opened when the first heat exchanger does not reach the condensing condition, the low pressure drop phenomenon of the compressor at the beginning of heating operation can be improved and the risk of compressor failure can be reduced.

[0035] According to at least one embodiment of the present invention, due to the gradual opening or closing of the second expansion device, the rapid pressure change applied to the cycle can be reduced, thereby reducing the load applied to the system.

[0036] According to at least one embodiment of the present invention, since the second expansion device is opened when the evaporation temperature of the refrigerant flowing into the compressor is below a predetermined temperature, the second expansion device can be opened when a low pressure drop phenomenon of the compressor actually occurs. Thus, unnecessary power waste can be reduced and the efficiency of the heat supply device can be improved.

[0037] According to at least one embodiment of the present invention, since the second expansion device is opened when the difference between the evaporation temperature of the refrigerant flowing into the compressor and the temperature of the outdoor air is above a specified temperature, the second expansion device can be opened when a low pressure drop phenomenon of the compressor actually occurs. Thus, unnecessary power waste can be reduced and the efficiency of the heat supply device can be improved.

[0038] According to at least one embodiment of the present invention, since the closing speed of the second expansion device is greater than the opening speed, the second expansion device is quickly closed when the condensing condition is reached, thereby minimizing the amount of liquid refrigerant flowing into the compressor.

[0039] According to at least one embodiment of the present invention, the open flow path area of ​​the second expansion device is formed to be larger than the flow path area of ​​the first expansion device, so that the opening degree of the entire flow path of the expansion device can be accurately adjusted.

[0040] 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

[0041] Figure 1 It is a schematic diagram of a heat supply device according to an embodiment of the present invention.

[0042] Figure 2 It is a control block diagram of a heat supply device according to an embodiment of the present invention.

[0043] Figure 3 Detailed description of the invention The following is a flowchart showing a method for controlling a heat supply device according to an embodiment of the present invention.

[0044] Figure 4 It is a flow chart of a control method of a heat supply device according to an embodiment of the present invention.

[0045] Figure 5 is a flow chart of a control method for a heat supply device according to another embodiment of the present invention.

[0046] Figure 6 is a flow chart of a control method for a heat supply device according to another embodiment of the present invention.

[0047] Figure 7 is a flow chart of a control method for a heat supply device according to another embodiment of the present invention.

[0048] Figure 8 is a flow chart of a control method for a heat supply device according to another embodiment of the present invention.

[0049] Fig. 9 is a flow chart of a control method for a heat supply device according to another embodiment of the present invention.

[0050] Fig.10 is a flow chart of a control method for a heat supply device according to another embodiment of the present invention.

[0051] Fig.11 This is a graph showing experimental results of pulses of the second expansion device caused by the pressure and evaporation temperature of the heat supply device according to one embodiment of the present invention.

[0052] Description of Reference Numerals

[0053] 10: Compressor

[0054] 20: Four-way valve

[0055] 30: First heat exchanger

[0056] 42: First expansion device

[0057] 44: Second expansion device

[0058] 46: Bypass pipe

[0059] 60: Second heat exchanger

[0060] 70: Accumulator

[0061] 80: Refrigerant piping

[0062] 100: Control Department DETAILED DESCRIPTION

[0063] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. Regardless of the figure numbers, the same or similar components are marked with the same reference numerals, and repeated descriptions thereof will be omitted.

[0064] The suffixes "module" and "unit" of the constituent elements used in the following description are given or used interchangeably only in consideration of ease of writing of the description, and they themselves do not have meanings or functions that distinguish one from another.

[0065] Furthermore, when describing the embodiments disclosed in this specification, if it is determined that the specific description of the related known technology may confuse the main idea of ​​the embodiments disclosed in this specification, the detailed description will be omitted. Furthermore, the drawings are only used to make the embodiments disclosed in this specification easier to understand, and it should be understood that the technical ideas disclosed in this specification are not limited by the drawings, but cover all changes, equivalents and substitutes included in the ideas and technical scope of the present invention.

[0066] Terms including ordinal numbers such as first, second, etc. may be used to describe various constituent elements, but the constituent elements are not limited by the terms. The terms are only used to distinguish one constituent element from other constituent elements.

[0067] When it is mentioned that a certain component is “connected” or “linked” to another component, it should be understood that it can be directly connected or linked to the other component, or other components may exist between them. On the contrary, when it is mentioned that a certain component is “directly connected” or “directly linked” to another component, it should be understood that there are no other components between them.

[0068] Unless clearly indicated otherwise in the context, an expression in the singular includes an expression in the plural.

[0069] In the present application, it should be understood that terms such as "include" or "have" are intended to indicate the existence of the features, numbers, steps, actions, constituent elements, parts or combinations thereof described in the specification, and cannot preclude the possibility of the existence or increase of one or more other features or numbers, steps, actions, constituent elements, parts or combinations thereof.

[0070] The directions of up (U), down (D), left (Le), right (Ri), front (F), and back (R) shown in the accompanying drawings are only for the convenience of explanation, and the technical ideas disclosed in this specification are not limited thereto.

[0071] Reference Figure 1 The heat supply device 1 may include: a compressor 10 for compressing a refrigerant; a first heat exchanger 30 for exchanging heat between the refrigerant and water; a second heat exchanger 60 for exchanging heat between the refrigerant and air; and an expansion device 40 disposed between the first heat exchanger and the second heat exchanger.

[0072] <awhp>

[0073] The heat supply device 1 may be an AWHP (Air to Water Heat Pump) that exchanges heat between water and refrigerant. The AWHP can use the heat energy of outdoor air to heat water circulating in the indoor space and heat the indoor space or supply hot water. The AWHP is mainly used for heating and hot water supply in cold places. On the contrary, the AWHP can transfer the heat energy of the indoor space to the refrigerant circulating in the outdoor unit through the water circulating in the indoor space, and the refrigerant can discharge the heat energy transferred from the indoor space to the outdoors. Thus, the AWHP can also cool the indoor space or supply cold water.

[0074] The compressor 10, the first heat exchanger 30, the second heat exchanger 60, and the expansion device 40 may constitute an outdoor unit. A water pipe 90 for the flow of water circulating in the indoor space may be connected to the first heat exchanger 30. The water pipe 90 may include: an inlet pipe 92 for supplying water to flow into the first heat exchanger 30; and an outlet pipe 94 for discharging water from the first heat exchanger 30. The inlet pipe 92 and the outlet pipe 94 may be connected to the first heat exchanger 30, respectively. A pump 93 for flowing water into the first heat exchanger 30 may be arranged on the inlet pipe 92. The water circulating in the water pipe 90 may exchange heat with the refrigerant of the circulating refrigerant pipe 80 in the first heat exchanger 30. Thus, the heat supply device 1 may heat or cool the indoor space.

[0075] <Refrigerant piping>

[0076] The heat supply device 1 may include a refrigerant pipe 80 connecting the compressor 10, the first heat exchanger 30, and the second heat exchanger 60. The refrigerant pipe 80 may form a closed circuit. The refrigerant discharged from the compressor 10 may circulate through the refrigerant pipe 80.

[0077] The refrigerant pipe 80 may include a first pipe 81 connected to the first heat exchanger 30, a second pipe 82 connecting the first heat exchanger 30 and the expansion device 40, a third pipe 83 connecting the expansion device 40 and the second heat exchanger 60, and a fourth pipe 84 connected to the second heat exchanger 60. The first pipe 81 may be located between the compressor 10 and the first heat exchanger 30. The fourth pipe 84 may be located between the compressor 10 and the second heat exchanger 60.

[0078] The heat supply device 1 may include a four-way valve 20 located between the compressor 10 and the first heat exchanger 30. The four-way valve 20 may be located between the compressor 10 and the second heat exchanger 60. The four-way valve 20 may switch the refrigerant piping 80 according to the operation mode. That is, the four-way valve 20 may connect the compressor 10 and the first heat exchanger 30 during the heating operation, and connect the compressor 10 and the second heat exchanger 60 during the cooling operation. For example, during the heating operation, the refrigerant discharged from the compressor 10 may flow to the first heat exchanger 30 through the four-way valve 20, and during the cooling operation, the refrigerant discharged from the compressor 10 may flow to the second heat exchanger 60 through the four-way valve 20.

[0079] The first pipe 81 may connect the first heat exchanger 30 and the four-way valve 20 . The fourth pipe 84 may connect the second heat exchanger 60 and the four-way valve 20 .

[0080] The refrigerant pipe 80 may include an inlet pipe 85 through which the refrigerant flowing into the compressor 10 flows. The inlet pipe 85 may be connected to the inlet side of the compressor 10. The inlet pipe 85 may connect the compressor 10 and the four-way valve 20.

[0081] The compressor 10 may be connected to the four-way valve 20. The refrigerant pipe 80 may include an outlet pipe 86 through which the refrigerant discharged from the compressor 10 flows. The outlet pipe 86 may be connected to the outlet side of the compressor 10. The outlet pipe 86 may connect the compressor 10 and the four-way valve 20.

[0082] The heat supply device 1 may include an accumulator 70 located between the four-way valve 20 and the compressor 10. The accumulator 70 may be located at the inlet piping 85. The accumulator 70 may be located upstream of the compressor 10 in the refrigerant flow path.

[0083] During the heating operation, the outlet pipe 86 can be connected to the first pipe 81 through the four-way valve 20, and the inlet pipe 85 can be connected to the fourth pipe 84 through the four-way valve 20. Thus, the refrigerant discharged from the compressor 10 can flow to the first heat exchanger 30. During the cooling operation, the outlet pipe 86 can be connected to the fourth pipe 84 through the four-way valve 20, and the inlet pipe 85 can be connected to the first pipe 81 through the four-way valve 20. Thus, the refrigerant discharged from the compressor 10 can flow to the second heat exchanger 60.

[0084] <Water-refrigerant heat exchanger>

[0085] The first heat exchanger 30 may be a water-refrigerant heat exchanger 30 that exchanges heat between water and refrigerant. For example, the first heat exchanger 30 may be a plate-shaped heat exchanger through which water and refrigerant flow separately. The first heat exchanger 30 may allow water circulating in the indoor space to pass through. The first heat exchanger 30 may allow refrigerant circulating in the outdoor unit to pass through. While the refrigerant circulates in the outdoor unit, it may exchange heat with outdoor air in the second heat exchanger 60 and with water in the first heat exchanger 30. Thus, the water circulating in the room may be heated or cooled. During the heating operation, the first heat exchanger 30 may heat the water passing through, thereby heating the indoor space or supplying hot water. During the cooling operation, the first heat exchanger 30 may cool the water passing through, thereby cooling the indoor space or supplying cold water. The water and refrigerant passing through the first heat exchanger 30 may flow relative to each other. That is, the water and the refrigerant may form a countercurrent.

[0086] During heating operation, the refrigerant discharged from the compressor 10 may flow toward the first heat exchanger 30. At this time, the first heat exchanger 30 may function as a condenser. The refrigerant passing through the first heat exchanger 30 may flow through the expansion device 40 and the second heat exchanger 60 in sequence.

[0087] During cooling operation, the refrigerant discharged from the second heat exchanger 60 may flow toward the first heat exchanger 30. At this time, the first heat exchanger 30 may function as an evaporator.

[0088] <Air-refrigerant heat exchanger>

[0089] The second heat exchanger 60 may be an air-refrigerant heat exchanger 60 that exchanges heat between air and refrigerant. For example, the second heat exchanger 60 may be a fin-tube heat exchanger including tubes and fins through which the refrigerant flows. The first heat exchanger 30 and the second heat exchanger 60 constitute an outdoor unit, so the second heat exchanger 60 may exchange heat between outdoor air and refrigerant.

[0090] During the heating operation, the refrigerant discharged from the first heat exchanger 30 may flow toward the second heat exchanger 60. At this time, the second heat exchanger 60 may function as an evaporator.

[0091] During cooling operation, the refrigerant discharged from the compressor 10 may flow toward the second heat exchanger 60. At this time, the second heat exchanger 60 may function as a condenser.

[0092] <Expansion device>

[0093] The expansion device 40 may be located between the first heat exchanger 30 and the second heat exchanger 60. During the heating operation, the refrigerant may pass through the expansion device 40 in the direction from the first heat exchanger 30 to the second heat exchanger 60. During the cooling operation, the refrigerant may pass through the expansion device 40 in the direction from the second heat exchanger 60 to the first heat exchanger 30. The expansion device 40 may be located between the second pipe 82 connected to the first heat exchanger 30 and the third pipe 83 connected to the second heat exchanger 60. The second pipe 82 and the third pipe 83 may be connected to the expansion device 40, respectively. For example, during the heating operation, the refrigerant may pass through the second refrigerant pipe 82, the expansion device 40, and the third refrigerant pipe 83 in sequence, and during the cooling operation, the refrigerant may pass through the third refrigerant pipe 83, the expansion device 40, and the second refrigerant pipe 82 in sequence.

[0094] <First Expansion Device>

[0095] The expansion device 40 may include a first expansion device 42 connected to the second pipe 82 and the third pipe 83. The first expansion device 42 may be an expansion valve.

[0096] <Second Expansion Device>

[0097] The expansion device 40 may include a second expansion device 44 connected in parallel with the first expansion device 42. The second expansion device 44 may be an electronic expansion valve (EEV) controlled by an electrical signal. The opening of the second expansion device 44 may be adjusted according to the electrical signal. For example, the opening of the second expansion device 44 may be adjusted between fully closed and fully open. Thus, the second expansion device 44 may adjust the overall flow path area of ​​the refrigerant piping 80 connecting the first heat exchanger 30 and the second heat exchanger 60. For example, if the second expansion device 44 is fully closed, the refrigerant piping 80 connecting the first heat exchanger 30 and the second heat exchanger 60 may form a minimum flow path area, and if the second expansion device 44 is fully open, the refrigerant piping 80 connecting the first heat exchanger 30 and the second heat exchanger 60 may form a maximum flow path area. Thus, the second expansion device 44 may make the circulation of the refrigerant smooth by adjusting the open area of ​​the flow path in which the expansion device 40 is configured.

[0098] The size of the second expansion device 44 may be larger than that of the first expansion device 42. The open flow path area of ​​the second expansion device 44 may be larger than the flow path area of ​​the first expansion device 42. Thus, the opening degree of the second expansion device 44 may be controlled more accurately.

[0099] <Single expansion device>

[0100] The expansion device 40 may be a single expansion device. The single expansion device may be an electronic expansion valve (EEV) whose opening is adjusted according to an electrical signal. At this time, the opening of the single expansion device may be adjusted between a minimum opening forming a minimum flow path area and a full opening forming a maximum flow path area. That is, the opening of the single expansion device may be adjusted while maintaining an open state, without being completely closed.

[0101] <Bypass pipe>

[0102] The heat supply device 1 may include a bypass pipe 46 configured with the second expansion device 44. The bypass pipe 46 may be connected to the refrigerant pipe 80 connecting the first heat exchanger 30 and the second heat exchanger 60. For example, one end of the bypass pipe 46 may be connected to the second pipe 82, and the other end of the bypass pipe 46 may be connected to the third pipe 83.

[0103] Reference Figure 2 The heat supply device 1 may include: a control unit 100; a temperature sensor 800 for collecting temperature information; and a pressure sensor 900 for collecting pressure information.

[0104] <Control Unit>

[0105] The heat supply device 1 may include a control part 100 which collects information and controls an operation state.

[0106] The control unit 100 can control the second expansion device 44. The control unit 100 can open and close the second expansion device 44. The control unit 100 can adjust the opening degree of the second expansion device 44.

[0107] The control unit 100 may separately control the compressor 10 and the outdoor fan 62. For example, if an operation signal is input, the control unit 100 may separately drive the compressor 10 and the outdoor fan 62.

[0108] The control unit 100 can control the four-way valve 20. For example, if a heating operation signal is input, the control unit 100 can control the four-way valve 20 to connect the first pipe 81 and the outlet pipe 86, and if a cooling operation signal is input, the control unit 100 can control the four-way valve 20 to connect the fourth pipe 84 and the inlet pipe 85.

[0109] <Temperature sensor - water-refrigerant heat exchanger side>

[0110] The temperature sensor 800 may include a condensation temperature sensor 830 for measuring the temperature of the refrigerant flowing into the first heat exchanger 30. The condensation temperature may refer to the temperature of the refrigerant flowing into the first heat exchanger 30. The condensation temperature sensor 830 may be located at the first pipe 81 or the first heat exchanger 30. The condensation temperature sensor 830 may transmit the measured condensation temperature to the control unit 100.

[0111] The temperature sensor 800 may include an inlet water temperature sensor 810 for measuring the temperature of water flowing into the first heat exchanger 30. The inlet water temperature may refer to the temperature of water flowing into the first heat exchanger 30. The inlet water temperature sensor 810 may be located at the inlet water pipe 92 or the first heat exchanger 30. The inlet water temperature sensor 810 may transmit the measured inlet water temperature to the control unit 100.

[0112] The temperature sensor 800 may include an outlet water temperature sensor 820 for measuring the temperature of water flowing out of the first heat exchanger 30. The outlet water temperature may refer to the temperature of water flowing out of the first heat exchanger 30. The outlet water temperature sensor 820 may be located at the outlet water pipe 94 or the first heat exchanger 30. The outlet water temperature sensor 820 may transmit the measured outlet water temperature to the control unit 100.

[0113] <Temperature sensor - air-refrigerant heat exchanger side>

[0114] The temperature sensor 800 may include an evaporation temperature sensor 840 for measuring the temperature of the refrigerant flowing into the second heat exchanger 60. The evaporation temperature may refer to the temperature of the refrigerant flowing into the second heat exchanger 60. Alternatively, the evaporation temperature may refer to the evaporation temperature of the refrigerant under the low pressure of the compressor 10. The evaporation temperature sensor 840 may be arranged on the low pressure side in the refrigerant piping 80. For example, it may be arranged in one of the third piping 83, the fourth piping 84, and the inlet piping 85. The evaporation temperature sensor 840 may transmit the measured evaporation temperature to the control unit 100.

[0115] The temperature sensor 800 may include an external air temperature sensor 850 for measuring the temperature of outdoor air. The external air temperature sensor 850 may measure the temperature of the airflow formed by the outdoor fan 62. The external air temperature sensor 850 may be located at the second heat exchanger 60. The external air temperature sensor 850 may transmit the measured external air temperature information to the control part 100.

[0116] <Pressure Sensor>

[0117] The pressure sensor 900 may include a low pressure sensor 910 for measuring the low pressure of the compressor 10. The low pressure sensor 910 may measure the pressure of the refrigerant flowing into the compressor 10. The low pressure sensor 910 may be located on the low pressure side of the refrigerant piping 80. For example, the low pressure sensor 910 may be located on one of the inlet piping 85, the third piping 83, and the fourth piping 84 of the compressor 10. The low pressure sensor 910 may transmit the measured low pressure information to the control unit 100.

[0118] The pressure sensor 900 may include a high pressure sensor 920 for measuring the high pressure of the compressor 10. The high pressure sensor 920 may measure the pressure of the refrigerant discharged from the compressor 10. The high pressure sensor 920 may be located on the high pressure side of the refrigerant piping 80. For example, the high pressure sensor 920 may be located on one of the outlet piping 86, the first piping 81, and the second piping 82 of the compressor 10. The high pressure sensor 920 may transmit the measured high pressure information to the control unit 100.

[0119] Reference Figure 3 The control method of the heat supply device may include: a step of determining an operation mode (S100); a step of collecting temperature information of the water-refrigerant heat exchanger 30 during heating operation (S200); a step of determining whether a condensation condition of the refrigerant is formed by the collected temperature information (S300); a step of collecting low-pressure information of the compressor 10 (S400); a step of determining whether the low pressure of the compressor 10 decreases by the collected low-pressure information (S500); a step of opening the second expansion device 44 when the low pressure of the compressor 10 decreases (S600); a step of collecting temperature information of the water-refrigerant heat exchanger 30 after the second expansion device 44 is opened (S200); a step of determining whether a condensation condition of the refrigerant is formed according to the opening of the second expansion device 44 (S300); and a step of closing the second expansion device 44 when the condensation condition of the refrigerant is formed (S700).

[0120] <Operation mode determination>

[0121] In the step (S100) of determining the operation mode, the control unit 100 can determine whether the heat supply device 1 is in heating operation or cooling operation. The control unit 100 can determine that it is heating operation when the refrigerant discharged from the compressor 10 flows to the first heat exchanger 30. In addition, the control unit 100 can determine that it is heating operation when the first pipe 81 and the outlet pipe 86 are connected. The control unit 100 can determine that it is cooling operation when the refrigerant discharged from the compressor 10 flows to the second heat exchanger 60. In addition, the control unit 100 can determine that it is cooling operation when the fourth pipe 84 and the inlet pipe 85 are connected.

[0122] <Water-refrigerant heat exchanger temperature information collection>

[0123] In the step (S200) of collecting temperature information of the water-refrigerant heat exchanger 30, temperature information of water and / or refrigerant may be collected. At this time, the water inlet temperature sensor 810 may measure the temperature of water flowing into the water-refrigerant heat exchanger 30. The water outlet temperature sensor 820 may measure the temperature of water flowing out of the water-refrigerant heat exchanger 30. The condensing temperature sensor 830 may measure the temperature of the refrigerant flowing into the water-refrigerant heat exchanger 30. In the step of collecting temperature information of the water-refrigerant heat exchanger 30, the collected temperature information may be transmitted to the control unit 100.

[0124] <Condensation Condition Judgment>

[0125] In the step of determining the condensation condition (S300), the control unit 100 may determine whether the condensation condition of the refrigerant is formed. At this time, the control unit 100 may determine whether the condensation condition of the refrigerant is formed by comparing the condensation temperature and the water inlet temperature. In addition, the control unit 100 may determine whether the condensation condition of the refrigerant is formed by comparing the water inlet temperature and the water outlet temperature instead of comparing the condensation temperature and the water inlet temperature.

[0126] <Low Voltage Information Collection>

[0127] In the step of collecting low pressure information ( S400 ), the control part 100 may collect low pressure information of the compressor 10 through the low pressure sensor 910 .

[0128] <Judging whether the low pressure has dropped>

[0129] In the step of determining whether the low pressure drops (S500), the control unit 100 may determine whether the collected low pressure value of the compressor 10 deviates from the appropriate pressure range of the compressor 10. For example, the control unit 100 may determine that the low pressure drops when the collected low pressure value of the compressor 10 is lower than the appropriate low pressure of the compressor.

[0130] <Second expansion device opening>

[0131] When the control unit 100 determines that the low pressure has dropped, the control unit 100 may open the second expansion device 44. Thus, the gas-phase refrigerant that has not been condensed while passing through the first heat exchanger 30 may smoothly pass through the opened second expansion device 44.

[0132] <Water-refrigerant heat exchanger temperature information collection>

[0133] After opening the second expansion device 44, the control unit 100 may collect temperature information of water and / or refrigerant in the water-refrigerant heat exchanger 30 through the temperature sensor 800. For example, the control unit 100 may collect temperature information of the refrigerant flowing into the water-refrigerant heat exchanger 30 through the condensing temperature sensor 830. In addition, the control unit 100 may collect temperature information of the refrigerant flowing into the water-refrigerant heat exchanger 30 through the water inlet temperature sensor 810. In addition, the control unit 100 may collect temperature information of water flowing out of the water-refrigerant heat exchanger 30 through the water outlet temperature sensor 820.

[0134] <Condensation Condition Judgment>

[0135] The control unit 100 may determine whether the condensation condition of the refrigerant is formed after opening the second expansion device 44. The control unit 100 may determine whether the condensation condition of the refrigerant is formed by comparing the condensation temperature and the water inlet temperature. In addition, the control unit 100 may determine whether the condensation condition of the refrigerant is formed by comparing the water inlet temperature and the water outlet temperature instead of the condensation temperature and the water inlet temperature.

[0136] <Second expansion device closed>

[0137] The control unit 100 may close the second expansion device 44 when the condensation condition of the refrigerant is reached after the second expansion device 44 is opened.

[0138] Reference Figure 4 The control method of the heat supply device 1 may include: a step of determining whether it is a heating operation (S100); a step of comparing the water inlet temperature and the condensing temperature of the water-refrigerant heat exchanger 30 during the heating operation (S320); a step of opening the second expansion device 44 when the water inlet temperature is greater than the condensing temperature (S600); a step of comparing the water inlet temperature and the condensing temperature again (S320); and a step of closing the second expansion device 44 when the water inlet temperature is less than the condensing temperature (S700).

[0139] <Operation mode determination>

[0140] In the operation mode determination step ( S100 ), the control unit 100 may determine whether the heat supply device 1 is in a heating operation state.

[0141] <When cooling>

[0142] The control unit 100 may determine that the cooling operation is in progress when the refrigerant discharged from the compressor 10 flows toward the second heat exchanger 60. In addition, the control unit 100 may determine that the cooling operation is in progress when the fourth pipe 84 and the inlet pipe 85 are connected. The control unit 100 may close the second expansion device 44 when it is determined that the heat supply device 1 is in the cooling operation state. For example, the control unit 100 may completely close the second expansion device 44 in the cooling operation state. At this time, the refrigerant may only pass through the first expansion device 42.

[0143] <When heating>

[0144] The control unit 100 may determine that the heating operation is in progress when the refrigerant discharged from the compressor 10 flows into the first heat exchanger 30. In addition, the control unit 100 may determine that the heating operation is in progress when the first pipe 81 and the outlet pipe 86 are connected.

[0145] <Condensation Condition Judgment>

[0146] When the control unit 100 determines that the heat supply device 1 is in the heating operation state, it can determine whether the condensation condition of the refrigerant is met by comparing the water inlet temperature and the condensation temperature. For example, the control unit 100 can determine that the condensation condition of the refrigerant is not met when the water inlet temperature is above the condensation temperature. On the contrary, the control unit 100 can determine that the condensation condition of the refrigerant is met when the water inlet temperature is lower than the condensation temperature.

[0147] <Second expansion device opening>

[0148] When the control unit 100 determines that the condensation condition is not reached, the second expansion device 44 may be opened. At this time, the control unit 100 may gradually open the second expansion device 44. For example, the control unit 100 may control to gradually open the second expansion device 44 with a predetermined pulse P1 at a predetermined period T1. Thus, the second expansion device 44 may be opened within a predetermined time.

[0149] <Condensation Condition Judgment>

[0150] After opening the second expansion device 44, the control unit 100 may determine again whether the condensation condition is met. If it is determined that the condensation condition is not met, the control unit 100 may keep the second expansion device 44 open. If it is determined that the condensation condition is met, the control unit 100 may close the second expansion device 44.

[0151] <Second expansion device closed>

[0152] After the control unit 100 opens the second expansion device 44, when it is determined that the condensation condition is reached, the second expansion device 44 may be closed. At this time, the control unit 100 may gradually close the second expansion device 44. For example, the control unit 100 may control to gradually close the second expansion device 44 with a predetermined pulse P2 at a predetermined period T2. Thus, the second expansion device 44 may be closed within a predetermined time.

[0153] <Closing Speed>Opening Speed>

[0154] The speed at which the control unit 100 closes the second expansion device 44 may be greater than the speed at which the second expansion device 44 is opened. That is, the time required from the state of opening the second expansion device 44 to closing the second expansion device 44 may be shorter than the time required from the state of closing the second expansion device 44 to opening the second expansion device 44. For example, when closing the second expansion device 44, the control unit 100 gradually closes the second expansion device 44 with the second pulse P2 in each second cycle T2, and when opening the second expansion device 44, the control unit gradually opens the second expansion device 44 with the first pulse P1 in each first cycle T1. At this time, the closing speed (V2=P2 / T2) of the second expansion device may be greater than the opening speed (V1=P1 / T1) of the second expansion device.

[0155] Reference Figure 5 The control method of the heat supply device may include, after the step (S320) of determining whether the condensation condition of the refrigerant is reached, the step (S500) of determining whether a low pressure drop of the compressor occurs.

[0156] <Determining whether the low pressure drops - First embodiment>

[0157] The control unit 100 may determine whether a low pressure drop of the compressor 10 has occurred when the condensation condition of the refrigerant is not reached. The control unit 100 may determine that a low pressure drop of the compressor 10 has occurred when the evaporation temperature of the refrigerant is below a predetermined temperature value. The evaporation temperature of the refrigerant may be determined according to the pressure of the refrigerant. The evaporation temperature of the refrigerant may be the evaporation temperature of the refrigerant under the low pressure of the compressor 10. The compressor 10 may have an appropriate pressure range for normal driving and an appropriate refrigerant temperature range corresponding thereto.

[0158] When the evaporation temperature of the refrigerant due to the low pressure of the compressor 10 is not within the appropriate refrigerant temperature range of the compressor 10 , the control unit 100 may determine that the low pressure drop of the compressor 10 has occurred.

[0159] When the evaporation temperature of the refrigerant caused by the low pressure of the compressor 10 is within the appropriate refrigerant temperature range of the compressor 10, the control unit 100 may determine that the low pressure drop of the compressor 10 has not occurred. At this time, the control unit 100 may close the second expansion device 44. For example, when the control unit 100 determines that the low pressure drop of the compressor 10 has not occurred, the second expansion device 44 may be gradually closed.

[0160] <Second expansion device opening>

[0161] When the control unit 100 determines that a low pressure drop of the compressor 10 occurs, the second expansion device 44 may be opened. At this time, the control unit 100 may gradually open the second expansion device 44. For example, the control unit 100 may control to gradually open the second expansion device 44 with a predetermined pulse P1 at a predetermined cycle T1. Thus, the second expansion device 44 may be opened within a predetermined time.

[0162] <Condensation Condition Judgment>

[0163] The control unit 100 may determine again whether the condensation condition is reached after opening the second expansion device 44. At this time, the control unit 100 may collect the water inlet temperature and the condensation temperature information again.

[0164] <Low pressure drop judgment>

[0165] When it is determined that the condensing condition is not reached, the control unit 100 may again determine whether a low pressure drop of the compressor 10 has occurred. When the low pressure drop of the compressor 10 remains unchanged, the control unit 100 may maintain the open state of the second expansion device 44. When it is determined that the low pressure drop phenomenon of the compressor 10 has been resolved, the control unit 100 may close the second expansion device 44.

[0166] <Second expansion device closed>

[0167] After opening the second expansion device 44, the control unit 100 may close the second expansion device 44 when it is determined that the condensing condition is reached or the low pressure drop of the compressor 10 is resolved. At this time, the control unit 100 may gradually close the second expansion device 44. For example, the control unit 100 may control to gradually close the second expansion device 44 with a predetermined pulse P2 at a predetermined period T2. Thus, the second expansion device 44 may be closed within a predetermined time.

[0168] Reference Figure 6 The control method of the heat supply device may include, after the step of determining whether the condensation condition of the refrigerant is reached, a step of determining whether the low pressure of the compressor 10 decreases by comparing the outside air temperature with the evaporation temperature (S540).

[0169] <Determining whether the low pressure drops - Second embodiment>

[0170] When the control unit 100 determines that the condensation condition of the refrigerant is not reached, it can determine whether the low pressure of the compressor 10 has dropped by comparing the outside air temperature and the evaporation temperature. The control unit 100 can determine that the low pressure of the compressor 10 has dropped when the difference between the outside air temperature and the evaporation temperature is greater than a predetermined temperature value. For example, the control unit 100 can determine that the low pressure of the compressor 10 has dropped when the value obtained by subtracting the evaporation temperature from the outside air temperature is greater than a predetermined temperature value T3.

[0171] <Second expansion device opening>

[0172] The control unit 100 may open the second expansion device 44 when it is determined that a low pressure drop of the compressor 10 occurs. At this time, the control unit 100 may gradually open the second expansion device 44. For example, the control unit 100 may control to gradually open the second expansion device 44 with a predetermined pulse P1 at a predetermined cycle T1. Thus, the second expansion device 44 may be opened within a predetermined time.

[0173] <Condensation Condition Judgment>

[0174] The control unit 100 may determine again whether the condensation condition is reached after opening the second expansion device 44. At this time, the control unit 100 may collect the water inlet temperature and the condensation temperature information again.

[0175] When it is determined that the condensing condition is not reached, the control unit 100 may again determine whether a low pressure drop of the compressor 10 has occurred. When the low pressure drop of the compressor 10 remains unchanged, the control unit 100 may maintain the open state of the second expansion device 44. When it is determined that the low pressure drop phenomenon of the compressor 10 has been resolved, the control unit 100 may close the second expansion device 44.

[0176] <Second expansion device closed>

[0177] After opening the second expansion device 44, the control unit 100 may close the second expansion device 44 when it is determined that the condensing condition is reached or the low pressure drop of the compressor 10 is resolved. At this time, the control unit 100 may gradually close the second expansion device 44. For example, the control unit 100 may control to gradually close the second expansion device 44 with a predetermined pulse P2 at a predetermined period T2. Thus, the second expansion device 44 may be closed within a predetermined time.

[0178] Reference Figures 7 to 9 In another embodiment, during the heating operation, a step of comparing the water inlet temperature and the condensation temperature of the water-refrigerant heat exchanger 30 may be included.

[0179] <Condensation Condition Judgment - Second Embodiment>

[0180] In the step (S300) of determining whether the condensation condition of the refrigerant is met, the control unit 100 may determine that the condensation condition of the refrigerant is not met when the water inlet temperature is greater than the condensation temperature by a predetermined temperature or more. For example, when the water inlet temperature is greater than the condensation temperature by a predetermined temperature t1 or more, the control unit 100 may determine that the condensation condition of the refrigerant is not met.

[0181] When the water inlet temperature does not reach the value obtained by adding the specified temperature value to the condensing temperature, the control unit 100 may determine that the condensing condition of the refrigerant is met. At this time, the control unit 100 may close the second expansion device 44. For example, when the water inlet temperature does not reach the value obtained by adding the specified temperature value t1 to the condensing temperature, the control unit 100 may determine that the condensing condition of the refrigerant is met, and may control the second expansion device to be gradually closed with the specified pulse P2 according to the specified period T2.

[0182] For steps other than the step of determining whether the condensation condition of the refrigerant is reached (S300), Figures 4 to 6 The description can be applied to Figures 7 to 9 .

[0183] Reference Fig.10 In the step of determining the condensation condition, the control unit may determine whether the condensation condition of the refrigerant is met by comparing the water inlet temperature and the water outlet temperature.

[0184] The control unit 100 may determine that the refrigerant condensation condition is not met when the inlet water temperature is higher than the outlet water temperature by a predetermined temperature or more. For example, the control unit 100 may determine that the refrigerant condensation condition is not met when the inlet water temperature is higher than the outlet water temperature by a predetermined temperature t4 or more.

[0185] When the inlet water temperature does not reach the value obtained by adding the specified temperature value to the outlet water temperature, the control unit 100 may determine that the condensation condition of the refrigerant is met. At this time, the control unit 100 may close the second expansion device 44. For example, when the inlet water temperature does not reach the value obtained by adding the specified temperature value t1 to the outlet water temperature, the control unit 100 may determine that the condensation condition of the refrigerant is not met, and may control the second expansion device to be gradually closed with the specified pulse P2 according to the specified period T2.

[0186] For steps other than the step of determining whether the condensation condition of the refrigerant is reached (S300), the following may be applied: Figures 4 to 6 Description.

[0187] Reference Fig.11 , illustrating the pulse variation of the second expansion device 44 caused by the low pressure variation of the compressor 10.

[0188] <Pressure-Evaporation Temperature Relationship>

[0189] The upper graph is a graph showing the time-varying high and low pressures of the compressor 10. When the compressor 10 starts to be driven, the high pressure of the compressor 10 may increase from about 100 kPa to about 800 kPa, and the low pressure of the compressor 10 may decrease from about 100 kPa to 50 kPa.

[0190] The middle graph is a graph showing the evaporation temperature of the refrigerant changing with time. The evaporation temperature of the refrigerant can be calculated by the low pressure of the compressor 10. That is, the change of the low pressure of the compressor 10 can be derived from the evaporation temperature. For example, if the low pressure of the compressor 10 increases, the evaporation temperature of the refrigerant can increase, and if the low pressure of the compressor 10 decreases, the evaporation temperature of the refrigerant can decrease. The evaporation temperature of the refrigerant from the start of the drive of the compressor 10 at the first time m1 to the second time m2 can drop from about -24 degrees to about -29 degrees. Then, the control unit 100 can change the evaporation temperature by adjusting the opening of the second expansion device 44.

[0191] <Evaporation temperature-pulse relationship>

[0192] The lower graph is a graph showing the pulse of the second expansion device 44 changing with time. The pulse may correspond to the opening of the second expansion device 44. As the pulse increases, the opening of the second expansion device 44 may increase, and as the pulse decreases, the opening of the second expansion device 44 may decrease.

[0193] After the drive of the compressor 10 starts, the low pressure and evaporation temperature of the compressor 10 become lower, and correspondingly, the control unit 100 may open the second expansion device 44. For example, the compressor 10 starts to drive at the first time m1, and as time passes, the high pressure of the compressor 10 increases, and the low pressure of the compressor 10 and the evaporation temperature of the refrigerant decrease. The control unit 100 senses that the low pressure of the compressor 10 drops, and thus may open the second expansion device 44 at the second time m2. When the control unit 100 opens the second expansion device 44 at the second time m2, the pulse of the second expansion device 44 may increase from 0 to about 150.

[0194] As the second expansion device 44 is opened, the evaporation temperature of the refrigerant may increase from about -29 degrees to about -26 degrees. After opening the second expansion device 44, the control unit 100 may gradually adjust the opening degree. For example, the control unit 100 may reduce the opening degree immediately after opening the second expansion device 44. Thus, the pulse of the second expansion device 44 may be reduced from about 150 to about 110. As the opening degree of the second expansion device 44 is reduced, the evaporation temperature of the refrigerant may decrease from about -26 degrees to about -33 degrees. That is, a low pressure drop of the compressor 10 may occur.

[0195] The control unit 100 can sense that the evaporation temperature of the refrigerant decreases, and can increase the opening of the second expansion device 44 at the third time m3. The control unit 100 can sense the change in the evaporation temperature of the refrigerant while gradually increasing or decreasing the opening of the second expansion device 44 in the interval from the third time m4 to the fourth time m4. The control unit 100 increases the pulse of the second expansion device 44 from about 110 to about 210 from the third time m3 to the fourth time m4, thereby increasing the evaporation temperature of the refrigerant from about -35 degrees to about -29 degrees. That is, the low pressure of the compressor 10 gradually rises, and the low pressure drop phenomenon can be solved.

[0196] The evaporation temperature of the refrigerant can be maintained within an appropriate range after the fourth time m4. The control unit 100 determines that the evaporation temperature of the refrigerant is within an appropriate range after the fourth time m4, and can gradually close the second expansion device 44. The second expansion device 44 can be completely closed at the fifth time m5.

[0197] Reference Figures 1 to 11 According to one aspect of the present invention, a heat supply device includes: a compressor for compressing a refrigerant; a first heat exchanger connected to the compressor by a refrigerant pipe so as to exchange heat between the refrigerant and water; a second heat exchanger connected to the compressor by a refrigerant pipe so as to exchange heat between the refrigerant and air; a first expansion device arranged on the refrigerant pipe connecting the first heat exchanger and the second heat exchanger; a second expansion device connected in parallel with the first expansion device and opened and closed according to an electrical signal; and a control unit for controlling the opening degree of the second expansion device; if the heating operation is started and the temperature of the water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger, the control unit can open the second expansion device.

[0198] According to another aspect of the present invention, the control unit may open the second expansion device if the temperature of water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger by a predetermined temperature or more.

[0199] According to another aspect of the present invention, when opening the second expansion device, the control unit may gradually open the second expansion device with a prescribed pulse at a prescribed cycle.

[0200] According to another aspect of the present invention, the control unit may open the second expansion device if the temperature of water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger and the evaporation temperature of the refrigerant flowing into the compressor is below a predetermined temperature.

[0201] According to another aspect of the present invention, if the temperature of water flowing into the first heat exchanger is greater than the temperature of the refrigerant flowing into the first heat exchanger and the difference between the evaporation temperature of the refrigerant flowing into the compressor and the temperature of the outdoor air is above a specified temperature, the control unit may open the second expansion device.

[0202] According to another aspect of the present invention, if the temperature of water flowing into the first heat exchanger after the second expansion device is opened is lower than the temperature of the refrigerant flowing into the first heat exchanger, the control unit may close the second expansion device.

[0203] According to another aspect of the present invention, when closing the second expansion device, the control unit may gradually close the second expansion device with a prescribed pulse at a prescribed period.

[0204] According to another aspect of the present invention, when opening the second expansion device, the control unit gradually opens the second expansion device with specified pulses at a specified period; the closing speed of the second expansion device may be greater than the opening speed of the second expansion device.

[0205] According to another aspect of the present invention, when the cooling operation is started, the control unit may close the second expansion device.

[0206] According to another aspect of the present invention, an open flow path area of ​​the second expansion device may be larger than a flow path area of ​​the first expansion device.

[0207] Reference Figures 1 to 11 In a control method for a heat supply device according to one aspect of the present invention, the heat supply device includes a compressor, a water-refrigerant heat exchanger, an air-refrigerant heat exchanger, a first expansion device arranged between the water-refrigerant heat exchanger and the air-refrigerant heat exchanger, and a second expansion device connected in parallel with the first expansion device, wherein the control method may include: a step of sensing the temperatures of the refrigerant and water flowing into the water-refrigerant heat exchanger when the refrigerant discharged from the compressor flows into the water-refrigerant heat exchanger; and a step of opening the second expansion device if the temperature of the water flowing into the water-refrigerant heat exchanger is greater than the temperature of the refrigerant flowing into the water-refrigerant heat exchanger.

[0208] According to another aspect of the present invention, in the step of opening the second expansion device, the second expansion device may be gradually opened with a prescribed pulse at a prescribed period.

[0209] According to another aspect of the present invention, between the step of sensing the temperature of the water-refrigerant heat exchanger and the step of opening the second expansion device, it also includes: a step of measuring the low pressure of the compressor and determining whether the low pressure of the compressor is below a specified pressure; the step of opening the second expansion device can be performed when the low pressure of the compressor is below the specified pressure.

[0210] According to another aspect of the present invention, in the step of determining whether the low pressure of the compressor is below a specified pressure, it can be determined that the low pressure of the compressor is below a specified pressure when the evaporation temperature of the measured low-pressure refrigerant is below a specified temperature.

[0211] According to another aspect of the present invention, in the step of determining whether the low pressure of the compressor is below a specified pressure, it can be determined that the low pressure of the compressor is below a specified pressure when the difference between the measured evaporation temperature of the low-pressure refrigerant and the temperature of the outdoor air is above a specified temperature value.

[0212] According to another aspect of the present invention, the control method may include: when the refrigerant discharged from the compressor flows into the air-refrigerant heat exchanger or the refrigerant discharged from the compressor flows into the water-refrigerant heat exchanger, if the temperature of water flowing into the water-refrigerant heat exchanger is lower than the temperature of the refrigerant flowing into the water-refrigerant heat exchanger, the step of closing the second expansion device.

[0213] According to another aspect of the present invention, after the step of opening the second expansion device, the control method may include: the step of sensing the temperatures of the refrigerant and water flowing into the water-refrigerant heat exchanger; and the step of closing the second expansion device if the temperature of the water flowing into the water-refrigerant heat exchanger is lower than the temperature of the refrigerant flowing into the water-refrigerant heat exchanger.

[0214] According to another aspect of the present invention, in the step of closing the second expansion device, the second expansion device may be gradually closed with a prescribed pulse at a prescribed period.

[0215] The aforementioned certain embodiments or other embodiments of the present invention do not exclude or distinguish each other. The various components or functions of the aforementioned certain embodiments or other embodiments of the present invention may be mixed or combined.

[0216] For example, this means that the A configuration described in a specific embodiment and / or drawing can be combined with the B configuration described in another embodiment and / or drawing. In other words, it means that even if the combination between the configurations is not directly described, they can be combined except for the case where it is described that they cannot be combined.

[0217] The above detailed description should not be interpreted as limiting in all aspects, but should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.< / awhp>

Claims

1. A heat supply device, wherein: include: compressor, which compresses the refrigerant; A first heat exchanger is connected to the compressor via a refrigerant pipe to exchange heat between the refrigerant and water; A second heat exchanger is connected to the compressor via a refrigerant pipe to exchange heat between the refrigerant and the air; a first expansion device disposed on a refrigerant pipe connecting the first heat exchanger and the second heat exchanger; a second expansion device, connected in parallel with the first expansion device, and opened and closed according to an electrical signal; and a control unit, controlling the opening degree of the second expansion device; The control unit opens the second expansion device when the heating operation is started and the temperature of the water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger.

2. The heat supply device according to claim 1, wherein: The control unit opens the second expansion device when the temperature of water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger by a predetermined temperature or more.

3. The heat supply device according to claim 1, wherein: When opening the second expansion device, the control unit gradually opens the second expansion device with a predetermined pulse at a predetermined cycle.

4. The heat supply device according to claim 1, wherein: The control unit opens the second expansion device when the temperature of water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger and the evaporation temperature of the refrigerant flowing into the compressor is equal to or lower than a predetermined temperature.

5. The heat supply device according to claim 1, wherein: The control unit opens the second expansion device when the temperature of water flowing into the first heat exchanger is higher than the temperature of the refrigerant flowing into the first heat exchanger and the difference between the evaporation temperature of the refrigerant flowing into the compressor and the temperature of the outdoor air is equal to or higher than a predetermined temperature.

6. The heat supply device according to claim 1, wherein: The control unit closes the second expansion device if the temperature of water flowing into the first heat exchanger after the second expansion device is opened is lower than the temperature of the refrigerant flowing into the first heat exchanger.

7. The heat supply device according to claim 6, wherein: When closing the second expansion device, the control unit gradually closes the second expansion device with a specified pulse at a specified period.

8. The heat supply device according to claim 7, wherein: When opening the second expansion device, the control unit gradually opens the second expansion device with a specified pulse according to a specified period; The closing speed of the second expansion device is greater than the opening speed of the second expansion device.

9. A control method for a heat supply device, the heat supply device comprising a compressor, a water-refrigerant heat exchanger, an air-refrigerant heat exchanger, a first expansion device disposed between the water-refrigerant heat exchanger and the air-refrigerant heat exchanger, and a second expansion device connected in parallel with the first expansion device, wherein: The control method comprises: When the refrigerant discharged from the compressor flows into the water-refrigerant heat exchanger, sensing the temperatures of the refrigerant and water flowing into the water-refrigerant heat exchanger; and The step of opening the second expansion device if the temperature of water flowing into the water-refrigerant heat exchanger is greater than the temperature of the refrigerant flowing into the water-refrigerant heat exchanger.

10. A heat supply device, wherein: include: compressor, which compresses the refrigerant; A first heat exchanger is connected to the compressor via a refrigerant pipe to exchange heat between the refrigerant and water; A second heat exchanger is connected to the compressor via a refrigerant pipe to exchange heat between the refrigerant and the air; a first expansion device disposed on a refrigerant pipe connecting the first heat exchanger and the second heat exchanger; a second expansion device, connected in parallel with the first expansion device, and opened and closed according to an electrical signal; as well as a control unit, controlling the opening degree of the second expansion device; The control unit opens the second expansion device when the heating operation is started and the temperature of water flowing into the first heat exchanger is higher than the temperature of water flowing out of the first heat exchanger by a predetermined temperature or more.

Images