JP2006145098A - Thermal storage air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the temperature of an indoor unit from being lowered by defrosting operation.
SOLUTION: During defrosting operation of a heat storage type air conditioner, brine is circulated in the brine side heat exchanger 12 and the heat storage tank 5 of the heat source device 1, and water is circulated in the heat exchanger 3 and the indoor unit 7. By doing so, since heat exchange between brine and water is not performed, it is possible to prevent the water flowing through the indoor unit 7 from being cooled by the brine cooled by the heat source unit 1. Therefore, a decrease in the temperature of the indoor unit 7 due to the defrosting operation can be prevented, and problems such as cold air blowing from the indoor unit 7 can be avoided.
[Selection] Figure 2

Description

  The present invention relates to a regenerative air conditioner, and more particularly to a regenerative air conditioner that performs a defrosting operation during heating operation.

  The heat storage type air conditioner uses heat at night to store heat in a heat storage tank, and uses it during heating operation in the daytime to reduce daytime power consumption. Such a heat storage type air conditioner is, for example, as disclosed in Patent Document 1, a heat source unit that heats a brine by a refrigerant in a refrigeration cycle, and a flow that circulates the brine to a heat exchanger or a heat storage tank connected in parallel. It comprises a channel and a channel for circulating water to the indoor unit through these heat exchangers and a heat storage tank. And at the time of heat storage operation, the brine in the heat storage tank is circulated to the heat storage tank by using the electric power at night, and the water in the tank is heated and stored. On the other hand, during heating operation, water is heated with brine through a heat exchanger, and the heated water is circulated through the heat storage tank to the indoor unit.

  In such a heat storage type air conditioner, when frost adheres to the surface of the evaporator of the refrigeration cycle that constitutes the heat source unit during heating operation, the performance of the heat source unit deteriorates. The air conditioner performs a defrosting operation in which the circulation direction of the refrigerant in the heat source unit is reversed and the high-temperature refrigerant flows through the evaporator periodically or when frost formation is detected.

Japanese Patent Laid-Open No. 8-28932 (see FIG. 5 and page 2)

  By the way, the heat storage type air conditioner of patent document 1 switches the heat | fever of a defrost from a heat storage tank by switching and circulating a brine from the heat exchanger which supplies warm water to an indoor unit at the time of a defrost operation. I am trying to supply.

  However, no consideration is given to a decrease in the temperature of the indoor unit due to a decrease in the temperature of the heat storage tank.

  The subject of this invention is preventing the temperature of an indoor unit falling by defrost operation.

  In order to solve the above problems, a heat storage air conditioner of the present invention includes a heat source device having a first heat exchanger that heats a first heat medium with a refrigerant of a refrigeration cycle, and a first heat medium in parallel. A first heat medium circulation passage provided with a first circulation pump that circulates to the first heat exchanger via a connected second heat exchanger and a heat storage tank, a second heat exchanger, and heat storage A second heat medium circulation passage provided with a second circulation pump that circulates the second heat medium in the tank via the indoor unit, a first heat on the inlet side of the second heat exchanger and the heat storage tank. A second heat exchanger inlet valve and a heat storage tank inlet valve respectively provided in the medium circulation flow path, a heat storage tank outlet valve provided in the second heat medium circulation flow path on the outlet side of the heat storage tank, Heating operation of the heat source device, comprising a bypass pipe connecting the inlet side of the heat storage tank of the heat medium circulation flow path and the downstream side of the outlet valve of the heat storage tank via a bypass valve In addition, the heat storage tank inlet valve and the bypass valve are closed, the second heat exchanger inlet valve and the heat storage tank outlet valve are opened, and the second heat exchanger inlet valve and the heat storage tank outlet valve are closed during the defrosting operation of the heat source unit. Control means for opening the heat storage tank inlet valve and the bypass valve is provided.

  That is, according to the present invention, during the defrosting operation of the heat source unit, the first heat medium (brine) is circulated through the first heat exchanger and the heat storage tank, and the second heat medium (water) is second heat exchanged. It was made to circulate between the unit and the indoor unit.

  Thereby, since heat exchange with the 1st heat carrier and the 2nd heat carrier is not performed at the time of defrosting operation, the 2nd circulating to the indoor unit by the 1st heat carrier cooled by defrosting operation It is possible to prevent the heat medium from being cooled. Accordingly, it is possible to avoid problems such as cold air blowing from the indoor unit.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that the temperature of an indoor unit falls by defrost operation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system configuration diagram during heating operation of a regenerative air conditioner to which the present invention is applied, and FIG. 2 is a system configuration diagram during defrosting operation. As shown in FIG. 1, the heat storage type air conditioner of this embodiment includes a heat source device 1, a heat exchanger 3, a heat storage tank 5, and an indoor unit 7.

  The heat source unit 1 is formed with a refrigeration cycle in which a compressor 11, a brine side heat exchanger 12 as a first heat exchanger, an expansion valve 13 and an air side heat exchanger 14 are sequentially connected. That is, the refrigerant discharged from the compressor 11 is led to the brine side heat exchanger 12 to be condensed, and this condensed liquid refrigerant is decompressed by the expansion valve 13 and then evaporated by the air side heat exchanger 14. It is returned to the compressor 11. In addition, the compressor 11 can perform a heating operation or a defrosting operation by switching a refrigerant discharge direction by a four-way valve 15.

  In the brine-side heat exchanger 12, the brine as the first heat medium flows and heat exchange with the refrigerant is performed. The brine discharged from the brine side heat exchanger 12 is circulated through the circulation flow path 22 by the circulation pump 21. The circulation channel 22 circulates the brine to the brine side heat exchanger 12 via the heat exchanger 3 and the heat storage tank 5 connected in parallel. That is, the brine outlet of the brine side heat exchanger 12 is connected to one end of the heat transfer channel 31 in the heat exchanger 3, and the other end of the heat transfer channel 31 is connected to the brine side heat exchanger 12 via the circulation pump 21. Connected to the brine inlet. Further, the heat medium circulation passages of the brine side heat exchanger 12 and the heat exchanger 3 are branched and connected to one end of a heat transfer tube 51 provided in the heat storage tank 5. The other end of the heat transfer tube 51 is commonly connected to the brine inlet of the brine side heat exchanger 12 via the circulation pump 21.

  On the other hand, the heat exchanger 3 and the heat storage tank 5 are provided with a circulation flow path 24 including a circulation pump 23 that circulates water as a second heat medium via the indoor unit 7. That is, the water outlet of the indoor unit 7 is connected to one end of a heat transfer channel 32 that is thermally connected to the heat transfer channel 31 provided in the heat exchanger 3. The other end of the heat transfer channel 32 is connected to the water inlet of the heat storage tank 5, and the water outlet of the heat storage tank 5 is connected to the water inlet of the indoor unit 7 via the circulation pump 23.

  An electric two-way valve 25 that is a second heat exchanger inlet valve is provided in the circulation flow path 22 on the inlet side of the heat exchanger 3, and an electric motor that is a heat storage tank inlet valve is provided on the circulation flow path 22 on the inlet side of the heat storage tank 5. Two-way valves 26 are respectively provided. A valve 27, which is a heat storage tank outlet valve, is provided in the circulation channel 24 on the outlet side of the heat storage tank 5. The inlet side of the heat storage tank 5 in the circulation channel 24 and the downstream side of the valve 27 are connected by a bypass channel 28. The bypass passage 28 is provided with a valve 29 which is a bypass valve. In the present embodiment, the valve 27 and the valve 29 are integrally formed as an electric three-way valve 30. The electric two-way valves 25 and 26 and the electric three-way valve 30 are controlled to be opened and closed by a controller (not shown).

  Next, the operation of the heat storage type air conditioner configured as described above will be described. First, during nighttime heat storage operation, the electric two-way valve 25 is fully closed and the electric two-way valve 26 is fully opened. And while operating the heat-source equipment 1, the circulation pump 21 is operated. Moreover, the circulation pump 23 stops. Thereby, the brine is heated by the heat source device 1, and the heated brine is circulated to the heat transfer tube 51 in the heat storage tank 5. As a result, the water in the heat storage tank 5 is heated by the brine and hot water is stored.

  During the daytime heating and air conditioning operation, as shown in FIG. 1, the electric two-way valve 25 is fully opened, the electric two-way valve 26 is fully closed, and the circulation pump 21 is operated. Further, the valve 27 of the electric three-way valve 30 is fully opened, the valve 29 is fully closed, and the circulation pump 23 is operated. In the figure, the white valves are open and the black valves are closed. Thereby, the brine is heated by the heat source device 1, and the heated brine is circulated to the heat exchanger 3. On the other hand, the hot water stored in the heat storage tank 5 is extracted by the circulation pump 23 and supplied to the indoor unit 7. The water discharged from the indoor unit 7 is reheated by the heat exchanger 3 and guided to the heat storage tank 5. In this way, a desired amount of heat is supplied to the indoor unit 7 to perform heating.

  Next, the operation | movement at the time of the defrost operation which is the characteristics of this embodiment is demonstrated with reference to FIG. The heat source unit 1 performs a defrosting operation by switching the four-way valve 15 periodically or when frosting is detected in order to eliminate a decrease in capacity due to frosting. In other words, the refrigerant discharged from the compressor 11 is condensed in the air-side heat exchanger 14, depressurized by the expansion valve 13, evaporated in the brine-side heat exchanger 12, and operated in a reverse cycle returning to the compressor 11. At this time, the controller fully closes the electric two-way valve 25 and fully opens the electric two-way valve 26 and operates the circulation pump 21. Further, the valve 27 of the electric three-way valve 30 is fully closed, the valve 29 is fully opened, and the circulation pump 23 is operated.

  Thereby, the refrigerant absorbs heat from the brine and moves the heat to the air-side heat exchanger 14 to perform defrosting. On the other hand, the brine cooled by the refrigerant circulates in the heat storage tank 5 to cool the water in the heat storage tank 5. At this time, water circulates in the heat exchanger 3 and the indoor unit. That is, water circulates without flowing through the heat storage tank 5.

  As described above, according to the present embodiment, the water circulated through the indoor unit 7 does not flow into the heat storage tank 5 but flows into the heat exchanger 3 so that heat exchange between brine and water is performed during the defrosting operation. Therefore, it is possible to prevent the water flowing through the indoor unit 7 from being cooled by the brine cooled by the heat source unit 1. Accordingly, it is possible to suppress a decrease in the temperature of the indoor unit due to the defrosting operation, and it is possible to suppress discomfort because no cold air is blown out from the indoor unit.

  In the present embodiment, the electric two-way valves 25 and 26 are provided. Alternatively, an electric three-way valve having the functions of the electric two-way valves 25 and 26 may be used. Conversely, the electric three-way valve 30 can be replaced with electric two-way valves 27 and 29.

It is a system configuration | structure figure at the time of the heating operation of the thermal storage type air conditioner of one Embodiment to which this invention is applied. It is a system configuration | structure figure at the time of the defrost driving | operation of the thermal storage type air conditioner of one Embodiment to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat source machine 3 Heat exchanger 5 Heat storage tank 7 Indoor unit 12 Brine side heat exchanger 14 Air side heat exchanger 21, 23 Circulation pump 25, 26 Electric two-way valve 27, 29 Valve 30 Electric three-way valve

Claims (1)

A heat source device having a first heat exchanger that heats the first heat medium with the refrigerant of the refrigeration cycle, a second heat exchanger in which the first heat medium is connected in parallel, and the heat storage tank through the heat storage tank. A first heat medium circulation passage having a first circulation pump that circulates to one heat exchanger, and a second heat medium circulated through the indoor unit to the second heat exchanger and the heat storage tank. A second heat medium circulation passage provided with a second circulation pump, and a second heat medium circulation passage provided on the inlet side of the second heat exchanger and the heat storage tank, respectively. Heat exchanger inlet valve and heat storage tank inlet valve, heat storage tank outlet valve provided in the second heat medium circulation channel on the outlet side of the heat storage tank, and heat storage in the second heat medium circulation channel A bypass pipe formed by connecting a tank inlet side and a downstream side of the heat storage tank outlet valve via a bypass valve, during heating operation of the heat source unit The heat storage tank inlet valve and the bypass valve are closed and the second heat exchanger inlet valve and the heat storage tank outlet valve are opened. During the defrosting operation of the heat source unit, the second heat exchanger inlet valve and the heat storage tank A regenerative air conditioner comprising control means for closing an outlet valve and opening the heat storage tank inlet valve and the bypass valve.

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