JP2015021680A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of failure such as gas leakage.SOLUTION: A refrigeration circuit is configured so that a branch pipe A is placed between a four-way valve 10 and a water-refrigerant heat exchanger 15, a branch pipe B is placed between the water-refrigerant heat exchanger 15 and an outdoor heat exchanger 11, a two-way valve C31 is provided between this branch pipe B and the indoor heat exchanger 11, an expansion valve B30 is provided between the indoor heat exchanger 11 and the branch pipe B, an expansion valve A29 is provided between the water-refrigerant heat exchanger 15 and the branch pipe B, and a water heat exchange sensor 40 is provided between the water-refrigerant heat exchanger 15 and the expansion valve A. The refrigeration circuit includes control units 14 and 20 that exert a control for an indoor unit to perform a heating operation in a case of the heating operation using solely the indoor unit by switching the four-way valve 10 to a heating side, slightly opening the expansion valve A, setting the expansion valve B to have an opening degree according to a heating capacity, and opening the two-way valve C. Furthermore, during the heating operation solely by the indoor unit, the control units 14 and 20 control a circulation pump 18 to be actuated if the water heat exchange sensor 40 detects that a detected temperature T is equal to or higher than a first predetermined temperature, and controls the circulation pump 18 to be stopped if the water heat exchange sensor 40 detects that the detected temperature T is lower than a second predetermined temperature lower than the first predetermined temperature.

Description

  The present invention relates to an air conditioner that simultaneously performs a cooling operation by refrigerant circulation in summer and a heating operation by refrigerant circulation and hot water heating operation by hot water circulation such as floor heating in winter.

  In a conventional air conditioner, a refrigeration circuit is configured by connecting a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, etc. with a refrigerant pipe, and a water-refrigerant in parallel with the indoor heat exchanger. A heat exchanger is connected, and the water-refrigerant heat exchanger and a hot water tank, a circulation pump and a heating heat exchanger such as a floor heater are connected by a hot water pipe to form a hot water circuit. Indoor heating is performed by a heating device that performs warm water heating such as floor heating using the hot water circuit, while simultaneously heating indoor air with warm air and simultaneously performing radiant heating for floor heating. It was something that improved. Moreover, the hot water circuit was stopped and only the refrigeration circuit and the indoor heat exchanger were operated to perform the cooling operation. (For example, see Patent Document 1)

JP 2001-336769 A

  In the conventional air conditioner, when only the heating operation in the indoor unit is performed, the four-way valve is directed to the heating side while the expansion valve on the hot water heating side (floor heating side) is maintained at a small opening. Switch to, and drive the compressor. Then, the refrigerant flows in order from the compressor to the indoor heat exchanger, the expansion valve, and the outdoor heat exchanger, and the outdoor heat exchanger functions as an evaporator and the indoor heat exchanger functions as a condenser. Although the heating operation of the machine can be performed, the expansion valve on the hot water heating side has a small opening, so that the refrigerant accumulates in the water-refrigerant heat exchanger and the indoor heat exchanger side is prevented from being short of the refrigerant. Although it is a small amount, the refrigerant flows through the water-refrigerant heat exchanger, so that the water-refrigerant heat exchanger is gradually heated, and the refrigeration circuit on the hot water heating side including the water-refrigerant heat exchanger becomes high pressure. There was concern about the occurrence of malfunctions such as gas leaks.

  The present invention pays attention to this point and solves the above-mentioned drawbacks. In particular, the configuration is such that a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, etc. are connected by a refrigerant pipe to constitute a refrigeration circuit. Then, a water-refrigerant heat exchanger is connected in parallel with the indoor heat exchanger by two branch pipes, and the water-refrigerant heat exchanger, the hot water tank, the circulation pump, and the heating heat exchanger such as floor heating are heated. In an air conditioner for connecting a pipe to form a hot water circuit, performing cooling operation or heating operation in an indoor unit by switching the refrigeration circuit, and performing hot water heating such as floor heating by the hot water circuit, the refrigeration In the circuit, a branch pipe A is located between the four-way valve and the water-refrigerant heat exchanger, and a branch pipe B is located between the water-refrigerant heat exchanger and the outdoor heat exchanger. A two-way valve C between the indoor heat exchanger and the branch pipe B, and an expansion valve B between the water- An expansion valve A is provided between the medium heat exchanger and the branch pipe B, and a hydrothermal sensor is provided between the water-refrigerant heat exchanger and the expansion valve A. In the cooling operation, the four-way valve is on the cooling side, and the expansion valve A is fully closed, the expansion valve B is opened according to the cooling capacity, and the two-way valve C is opened to perform cooling operation in the indoor unit. In the heating operation of the indoor unit alone, the four-way valve is set to the heating side. In addition, the expansion valve A is opened slightly, the expansion valve B is opened according to the heating capacity, and the two-way valve C is opened, so that the heating operation is performed in the indoor unit. The floor heating operation is performed by closing the valve on the heating side, the expansion valve A is fully open, the expansion valve B is fully closed, and the two-way valve C is closed. In the combined heating operation of the indoor unit and floor heating, the four-way valve is On the heating side, the expansion valve A is opened according to the heating capacity, the expansion valve B is opened according to the heating capacity, and the two-way valve C is opened. When the detected temperature T detected by the hydrothermal sensor detects a temperature equal to or higher than the first predetermined temperature during the heating operation of the indoor unit alone, the circulation pump is operated, and the detected temperature T is lower than the first predetermined temperature. (2) A controller for stopping the circulation pump when a temperature lower than a predetermined temperature is detected is provided.

  According to the present invention, when the temperature T detected by the hydrothermal sensor detects a temperature equal to or higher than the first predetermined temperature during the heating operation of the indoor unit alone, the circulation pump is operated, and the detected temperature T is lower than the first predetermined temperature. 2 Since a control unit is provided to stop the circulation pump when a temperature lower than a predetermined temperature is detected, it is possible to prevent the refrigerant from accumulating in the water-refrigerant heat exchanger and the indoor heat exchanger side from running out of refrigerant, and at the same time The condensing pressure in the exchanger is lowered, and the refrigeration circuit on the hot water heating side including the water-refrigerant heat exchanger becomes a high pressure to prevent the occurrence of failure such as gas leakage, thereby improving the product life and reliability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Operation | movement explanatory drawing of the valve apparatus.

Next, an air conditioner according to the present invention will be described with reference to an embodiment shown in the drawings.
Reference numeral 1 denotes an outdoor unit of an air conditioner, which is divided into two upper and lower chambers by a horizontal partition plate 2, which includes a refrigeration circuit chamber 3 at a lower portion and a hot water circuit chamber 4 at an upper portion, and an indoor unit 6 by a refrigerant communication pipe 5. Are connected to the floor heating panel 8 by a hot water communication pipe 7.
Inside the refrigeration circuit chamber 3, a compressor 9, a four-way valve 10, an outdoor heat exchanger 11, various valve devices 12, a blower fan 13, a refrigeration circuit control unit 14, and the like are provided.
Inside the hot water circuit chamber 4, a water-refrigerant heat exchanger 15, an auxiliary heater 16, a hot water tank 17, a circulation pump 18, a hot water header 19, a hot water circuit control unit 20, and the like are provided.
The indoor unit 6 includes a fin tube type indoor heat exchanger 21, an indoor fan 22, and an indoor controller 23.

Reference numeral 24 denotes a refrigeration circuit in which the compressor 9, the four-way valve 10, the water-refrigerant heat exchanger 15, the various valve devices 12, and the outdoor heat exchanger 11 are communicated with each other through a refrigerant pipe 25. A branch pipe A26 that branches the refrigerant to the water-refrigerant heat exchanger 15 side and the indoor heat exchanger 21 side is also branched between the water-refrigerant heat exchanger 15 and the outdoor heat exchanger 11 between the water-refrigerant heat exchanger 15 and the outdoor heat exchanger 11. A tube B27 is provided.
The branch pipe A26 and the branch pipe B27 are connected to the indoor heat exchanger 21 via the refrigerant connection valve 28 and the refrigerant communication pipe 5.

The various valve devices 12 are composed of two expansion valves, an expansion valve A29, an expansion valve B30, and a two-way valve C31, and one two-way valve, and are provided at respective positions to be described later.
An expansion valve A29 is provided between the water-refrigerant heat exchanger 15 and the branch pipe B27, an expansion valve B30 is provided between the branch pipe B27 and the refrigerant connection valve 28, and between the branch pipe A26 and the refrigerant connection valve 28. Is provided with a two-way valve C31.

  In the cooling operation, the four-way valve 10 is switched to the cooling side, the expansion valve A29 is fully closed, the expansion valve B30 is opened according to the cooling capacity, and the two-way valve C is opened. Then, the high-temperature refrigerant dissipates heat by passing through the four-way valve 10 and the outdoor heat exchanger 11, depressurizes it by the expansion valve B30, becomes low temperature by the indoor heat exchanger 21, and sends cold air indoors by the indoor blower fan 22. In this way, cooling is performed.

  In the heating operation of the indoor unit alone, the four-way valve 10 is switched to the heating side, the expansion valve A29 is opened slightly by about 10%, the expansion valve B30 is opened according to the heating capacity, and the two-way valve C31 is opened. Thus, the high-temperature refrigerant pressurized by the compressor 1 is heated by heating the room with the four-way valve 10, the two-way valve C31, and the indoor heat exchanger 21, and is squeezed and depressurized with the expansion valve B30. The refrigerant that has become low in temperature makes the outdoor heat exchanger 11 low in temperature, absorbs heat from the air, and is sent to the compressor 9. Here, during the individual unit heating operation of the indoor unit, the expansion valve A29 is opened a little so that the refrigerant accumulates in the water-refrigerant heat exchanger 15, and the amount of refrigerant circulating in the refrigeration circuit is reduced, thereby reducing the balance in the refrigeration circuit. It is possible to prevent the occurrence of problems such as lack of capacity due to collapse.

  In the heating operation of the floor heating alone, the four-way valve 10 is set to the heating side, the expansion valve A29 is opened according to the heating capacity, the expansion valve B30 is fully closed, and the two-way valve C31 is closed. The high-pressure refrigerant thus heated is heated by the floor heating panel 8 by heating the hot water circuit 32 with the four-way valve 10 and the water-refrigerant heat exchanger 15.

  In the combined heating operation of the indoor unit and floor heating, the four-way valve 10 is set to the heating side, the expansion valve A29 is set to an opening corresponding to the heating capacity, the expansion valve B30 is set to the opening corresponding to the heating capacity, and the two-way valve C is set to By opening, the opening degree of the expansion valve A29 and the expansion valve B30 is adjusted according to the importance of heating and floor heating in the indoor unit and the user's preference, and the amount of heat distribution on the indoor unit side and floor heating side is adjusted. After the adjustment, an appropriate refrigerant is evaporated in the outdoor heat exchanger 11.

  In the defrosting operation during the indoor unit single heating operation, the four-way valve 10 is set to the cooling side, the expansion valve A29 is fully closed, the expansion valve B30 is fully open, and the two-way valve C is opened, so that the high temperature from the compressor 9 is reached. The refrigerant is supplied to the outdoor heat exchanger 11 and the defrosting operation is performed while the refrigeration circuit on the indoor unit side is open. Therefore, the temperature of the indoor heat exchanger 21 decreases during the defrosting operation.

  In the defrosting operation during the floor heating single operation, the four-way valve 10 is turned to the cooling side, the expansion valve A29 is fully opened, the expansion valve B30 is fully closed, and the two-way valve C is closed. Since the refrigerant flows through the outdoor heat exchanger 11 and the defrosting operation is performed with the water-refrigerant heat exchanger 15 side refrigeration circuit open, the temperature on the hot water circuit 32 side decreases during the defrosting operation.

  In the defrosting in the indoor unit floor heating combined operation, the four-way valve 10 is set to the cooling side, the expansion valve A29 is fully closed, the expansion valve B30 is fully opened, and the two-way valve C is opened as in the indoor unit single heating operation. Thus, since a high-temperature refrigerant is allowed to flow from the compressor 9 to the outdoor heat exchanger 11 and the defrosting operation is performed with the refrigeration circuit on the indoor unit side open, the temperature of the indoor heat exchanger 21 decreases during the defrosting operation. The temperature drop on the warm water circuit 32 side of the floor heating is reduced.

  In the hot water circuit 32, the water-refrigerant heat exchanger 15, the auxiliary heater 16, the hot water tank 17, and the circulation pump 18 are communicated with the floor heating panel 8 through the hot water header 19 and the hot water connection pipe 7 through the hot water pipe 33. In the warm water circuit, the circulation rate of the warm water is adjusted by connecting the circulation pump 18 and the warm water header 19 and between the warm water header 19 and the water-refrigerant heat exchanger 15 by the warm water bypass circuit 34. A warm water connection valve 35 connects the warm water communication pipe 7 and the floor heating panel 8.

  The indoor heat exchanger 21 and the water-refrigerant heat exchanger 15 are connected in parallel to the refrigeration circuit 24. By switching between the two expansion valves A and B, the two-way valve C, and the four-way valve 10, the cooling operation is performed. Sometimes the refrigerant is circulated only to the indoor heat exchanger 21 side to cool the room, and during the heating operation, the refrigerant is circulated to both the indoor heat exchanger 21 and the water-refrigerant heat exchanger 15, and the indoor unit 6 is heated by hot air. The floor heating panel 8 can perform the heating operation simultaneously with the floor heating operation by the hot water circulation, but the heating operation can also be performed with only one of them.

The compressor 9 changes the rotational speed in multiple stages according to the amount of heat required by an inverter drive circuit (not shown) provided in the refrigeration circuit control unit 14.
The expansion valves A29 and B30 are electronic expansion valves whose opening degree is controlled by the refrigeration circuit control unit 14 according to the rotational speed of the compressor 9, the temperature of each part of the refrigeration circuit, and the like, and the two-way valve C31 is in the operation mode. In response, the refrigeration circuit controller 14 opens and closes the same.
The blower fan 13 is a resin propeller fan, which is rotated by a blower motor (not shown) having a variable number of rotations, and blows air to the outdoor heat exchanger 11 to perform heat exchange.

The indoor unit 6 is driven by an indoor blower fan 22 and sucks indoor air from a suction port (not shown) provided on the front surface and the upper surface, and exchanges heat with the indoor heat exchanger 21, and then is provided at the lower front surface. The air whose temperature is adjusted is blown into the room from the air outlet (not shown).
A refrigerant connection valve 36 connects the indoor unit 6 and the refrigerant communication pipe 5.

  The water-refrigerant heat exchanger 15 is composed of a double pipe having an inner pipe inserted into the outer pipe. The outer surface of the inner pipe is configured so that a large number of fins are erected to increase the heat exchange efficiency inside and outside the inner pipe. By making a hot water path (not shown) through which water passes inside the inner pipe of the double pipe and a refrigerant path (not shown) through which refrigerant passes between the inner pipe and the outer pipe, It is possible to heat the water passing through the heat exchange.

  Reference numeral 37 denotes a discharge temperature sensor attached to the refrigerant pipe on the discharge side of the compressor 9, which measures the discharge temperature of the compressor 9 and sends a signal to the refrigeration circuit control unit 14. Reference numeral 38 denotes an outside air temperature sensor provided on the upstream side of an outdoor air flow path (not shown) in the refrigeration circuit chamber 3, and measures the outside air temperature. Reference numeral 39 denotes an air heat exchange sensor that is attached to the outdoor heat exchanger 11 and measures the temperature of the outdoor heat exchanger 11 to control the defrosting operation. A hydrothermal sensor 40 is attached to a refrigerant pipe between the water-refrigerant heat exchanger 15 and the expansion valve A29 and measures the temperature of the refrigerant.

  Reference numeral 41 denotes an outgoing hot water sensor which is attached to a hot water pipe between the water-refrigerant heat exchanger 15 and the auxiliary heater 16 and measures the pipe temperature. A heater pipe sensor 42 is attached to a hot water pipe between the auxiliary heater 16 and the hot water tank 17 and measures the pipe temperature. Reference numeral 43 denotes a return hot water sensor which is attached to a hot water pipe between the floor heating panel 8 and the water-refrigerant heat exchanger 15 and measures the pipe temperature. Reference numeral 44 denotes a safety thermo that detects overheating of the auxiliary heater 16, and two are attached to the upper surface of the auxiliary heater 16. Reference numeral 45 denotes a room temperature sensor provided on the indoor air suction side.

  The operation during the heating operation of the indoor unit alone will be described. In the heating operation of the indoor unit alone, the four-way valve 10 is switched to the heating side by the refrigeration circuit control unit 14 and the hot water circuit control unit 20, and the expansion valve A29 is fully opened. When the expansion valve B30 is opened slightly according to the heating capacity and the two-way valve C31 is opened, the high-temperature refrigerant pressurized by the compressor 1 is the four-way valve 10, the two-way valve. C31, the indoor heat exchanger 21 heats the room for heating, and the refrigerant, which has been cooled down by being throttled and decompressed by the expansion valve B30, cools the outdoor heat exchanger 11 to absorb the heat from the air, and the compressor 9 Sent to. Here, during the individual unit heating operation of the indoor unit, the expansion valve A29 is opened a little so that the refrigerant accumulates in the water-refrigerant heat exchanger 15, and the amount of refrigerant circulating in the refrigeration circuit is reduced, thereby reducing the balance in the refrigeration circuit. However, the temperature of the water-refrigerant heat exchanger 15 gradually increases because a small amount of refrigerant continues to flow through the water-refrigerant heat exchanger 15 at all times. If the pressure rises and the pressure of the water-refrigerant heat exchanger 15 and the surrounding refrigeration circuit rises extremely, a failure such as gas leakage will occur. Therefore, when the detected temperature T detected by the hydrothermal sensor 40 is equal to or higher than the first predetermined temperature of about 60 ° C., the circulation pump 18 is operated to circulate the hot water in the hot water circuit 32, thereby water-refrigerant heat exchange. The temperature of the vessel 15 is lowered, and when the temperature T detected by the hydrothermal sensor 40 is less than the second predetermined temperature of about 40 ° C., the circulation pump 18 is stopped. After the circulation pump 18 is stopped, the temperature of the hydrothermal sensor 40 starts to rise again. However, the temperature of the hydrothermal sensor 40 is between the first predetermined temperature (60 ° C.) and the second predetermined temperature (40 ° C.). By turning ON / OFF 18, the pressure of the refrigeration circuit on the hot water heating side including the water-refrigerant heat exchanger 15 can be maintained at an appropriate pressure, preventing the occurrence of failures such as gas leakage, and the life of the product And improve reliability.

  In this embodiment, the first predetermined temperature is set to 60 ° C., but the condensing endurance pressure of the R410a refrigerant is 4.2 megapascal, which corresponds to 65 ° C. at the condenser temperature, The first predetermined temperature is set to 60 ° C. in consideration of a margin of 5 degrees. However, if the refrigerant to be used is different, the condensation durability pressure also changes, and the first predetermined temperature is also reduced accordingly. Further, the second predetermined temperature is set to 40 ° C., which is set by the temperature difference from the first predetermined temperature. If this temperature difference is small, the circulation pump 18 is frequently turned on and off, and the temperature difference Is too large and the temperature of the circulating water in the hot water circuit 24 is too low.

  Thus, when the temperature T detected by the hydrothermal sensor 15 detects the first predetermined temperature or higher during the heating operation of the indoor unit alone, the circulation pump 18 is operated, and the detected temperature T is lower than the first predetermined temperature. 2 Since the control units 14 and 20 are provided to stop the circulation pump 18 when a temperature lower than a predetermined temperature is detected, it is possible to prevent the refrigerant from being accumulated in the water-refrigerant heat exchanger 15 and the indoor heat exchanger 21 side from becoming insufficient. At the same time, the condensing pressure in the water-refrigerant heat exchanger 15 is lowered, the hot water heating side refrigeration circuit including the water-refrigerant heat exchanger 15 becomes high pressure to prevent the occurrence of malfunctions such as gas leakage, etc. It improves the performance.

DESCRIPTION OF SYMBOLS 1 Outdoor unit 6 Indoor unit 8 Floor heating panel 9 Compressor 11 Outdoor heat exchanger 14 Refrigeration circuit control part 15 Water-refrigerant heat exchanger 18 Circulation pump 20 Hot water circuit control part 21 Indoor heat exchanger 29 Expansion valve A
30 Expansion valve B
31 Two-way valve C
40 Hydrothermal sensor

Claims (1)

Compressor, four-way valve, indoor heat exchanger, expansion valve, outdoor heat exchanger, etc. are connected by refrigerant piping to form a refrigeration circuit, and water-refrigerant heat exchange in parallel with the indoor heat exchanger by two branch pipes And connect the water-refrigerant heat exchanger and the hot water tank, the circulation heat pump and the heating heat exchanger such as floor heating with a hot water pipe to form a hot water circuit. In an air conditioner that performs cooling operation and heating operation, and performs hot water heating such as floor heating by the hot water circuit,
In the refrigeration circuit, a branch pipe A is located between the four-way valve and the water-refrigerant heat exchanger, and a branch pipe B is located between the water-refrigerant heat exchanger and the outdoor heat exchanger. Two-way valve C between the exchangers
An expansion valve B is provided between the indoor heat exchanger and the branch pipe B.
An expansion valve A is provided between the water-refrigerant heat exchanger and the branch pipe B.
A hydrothermal sensor is provided between the water-refrigerant heat exchanger and the expansion valve A;
In the cooling operation, the four-way valve is set to the cooling side, the expansion valve A is fully closed, the expansion valve B is opened according to the cooling capacity, and the two-way valve C is opened.
In the heating operation of the indoor unit alone, the four-way valve is heated to the heating side, the expansion valve A is opened slightly, the expansion valve B is opened according to the heating capacity, and the two-way valve C is opened. Drive,
In the floor heating only heating operation, the floor heating operation is performed by closing the four-way valve to the heating side, the expansion valve A is fully open, the expansion valve B is fully closed, and the two-way valve C is closed.
In the combined heating operation of the indoor unit and floor heating, the four-way valve is opened to the heating side, the expansion valve A is opened according to the heating capacity, the expansion valve B is opened according to the heating capacity, and the two-way valve C is opened. Therefore, the combined heating operation of the indoor unit and floor heating is performed,
During the heating operation of the indoor unit alone, when the detected temperature T detected by the hydrothermal sensor detects a temperature equal to or higher than the first predetermined temperature, the circulation pump is operated, and the detected temperature T is lower than the first predetermined temperature and lower than the second predetermined temperature. An air conditioner characterized in that a control unit is provided to stop the circulation pump when it is detected.

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