JP6469489B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus, and more particularly to a refrigeration cycle apparatus that supplies cold / hot heat to a user side by heating / cooling a user side heat medium such as water / brine.

  Some refrigeration cycle apparatuses that supply cold / hot heat include plate-type heat exchangers on the use side heat exchanger and the heat source side heat exchanger. In the use-side heat exchanger, cold water or hot water used in the use-side equipment exchanges heat with the refrigerant in the refrigeration cycle. In heat-source-side heat exchange, heat source water such as groundwater or factory wastewater exchanges heat with the refrigerant in the refrigeration cycle. To do.

JP 2014-178110 A

  The above-described refrigeration cycle apparatus is provided with a four-way valve so that cold water and hot water can be used in the use side device, and switches between heating operation and cooling operation. However, in the case of the refrigeration cycle apparatus that switches between the cooling operation and the heating operation, the amount of refrigerant required differs between the cooling operation and the heating operation, so that excess refrigerant is generated during the heating operation. In general, surplus refrigerant is stored in an accumulator, a receiver tank, or the like provided in the refrigeration cycle. However, the refrigeration cycle apparatus becomes large and costs increase in order to secure a space for providing the accumulator or receiver tank.

  The problem to be solved by the present invention is to provide a refrigeration cycle apparatus capable of suppressing an increase in cost without increasing the size of the refrigeration cycle apparatus.

In the refrigeration cycle apparatus of the embodiment, the compressor, the first plate heat exchanger that exchanges heat between the refrigerant and the heat source side heat medium, the four-way valve, the expansion device, the refrigerant and the use side heat medium exchange heat. A refrigeration cycle apparatus configured by connecting a second plate type heat exchanger to the first plate with a refrigerant pipe connected to the first plate by the volume of the refrigerant pipe between the second plate type heat exchanger and the expansion device The refrigerant pipe between the second plate heat exchanger and the expansion device is larger than the volume of the refrigerant pipe between the first heat exchanger and the expansion device. And a second large diameter portion having an inner diameter larger than the first large diameter portion, and the first large diameter portion is the second plate type. Used in the bent portion of the refrigerant pipe between the heat exchanger and the expansion device, the second large diameter portion is the second Ru used straight tube portion of the refrigerant pipe between the rate type heat exchanger and the expansion device.

The perspective view which shows the internal structure of the refrigerating-cycle apparatus of embodiment. The refrigeration cycle block diagram of the refrigeration cycle apparatus of embodiment.

Hereinafter, the refrigeration cycle apparatus of the embodiment will be described with reference to the drawings.
FIG. 1 is a perspective view showing the internal structure of the refrigeration cycle apparatus of the present embodiment. FIG. 2 shows a refrigeration cycle configuration according to this embodiment, FIG. 2 (a) is a refrigeration cycle configuration diagram showing the flow of refrigerant and heat medium during cooling operation, and FIG. 2 (b) is a heating operation. It is a refrigeration cycle block diagram which shows the flow of the refrigerant | coolant and heat medium at the time.

  As shown in FIGS. 1 and 2, the refrigeration cycle apparatus 100 includes three compressors 1 connected in parallel. The discharge port of each compressor 1 is connected to a discharge collecting pipe 11, and the other end of the discharge collecting pipe 11 is connected to one end of a refrigerant flow path 3 </ b> A of the first plate heat exchanger 3 via a four-way valve 2. The The other end of the refrigerant flow path 3A is connected to one end of the refrigerant flow path 5A of the second plate heat exchanger 5 via two expansion valves (expansion devices) 4 provided in parallel. The other end of the refrigerant flow path 5 </ b> A is connected to one end of the suction collecting pipe 12 via the four-way valve 2. The other end of the suction collecting pipe 12 is branched and connected to the suction port of each compressor 1 by piping. These pipe connections constitute a heat pump refrigeration cycle. This heat pump refrigeration cycle is filled with a refrigerant such as R410A or R32.

As shown in FIG. 2, the first plate heat exchanger 3 is formed with a heat medium flow path 3 </ b> B through which a heat source side heat medium that exchanges heat with the refrigerant flowing through the refrigerant flow path 3 </ b> A flows. Heat source water such as factory effluent and groundwater flows through the heat medium flow path 3B as a heat source side heat medium.
The second plate heat exchanger 5 is formed with a heat medium flow path 5B through which a use side heat medium that exchanges heat with the refrigerant flowing through the refrigerant flow path 5A flows. In the heat medium flow path 5B, water or brine flows as a use side heat medium.
In the present embodiment, the first plate heat exchanger 3 and the second plate heat exchanger are composed of the same plate heat exchanger.

In the present embodiment, the three compressors 1 are each composed of a constant speed scroll compressor. In addition, the compressor 1 may be comprised with the rotary compressor carrying DC brushless motor which controls rotation speed by an inverter (not shown). The number of compressors 1 may be one or two.
Each of the expansion valves 4 is a so-called pulse motor valve whose opening degree changes continuously according to the number of pulses of the input drive pulse signal, and is provided in parallel. The number of expansion valves 4 may be one.

As shown in FIG. 1, the refrigerant pipe 7 provided between the expansion valve 4 and the second plate heat exchanger 5 is a refrigerant pipe provided between the expansion valve 4 and the first plate heat exchanger 3. A volume larger than 6 is provided.
More specifically, the refrigerant pipe 6 is composed of one copper pipe having an inner diameter of about 19 mm, a pipe length of about 700 mm, and a volume of about 0.2 L. On the other hand, the refrigerant pipe 7 is connected to two copper pipes having an inner diameter of about 30 mm, a pipe length of about 300 mm, and a volume of about 0.2 L, and a copper pipe having an inner diameter of about 47 mm, a pipe length of about 400 mm, and a volume of about 0.7 L. Composed. Hereinafter, a copper tube having an inner diameter of about 30 mm is referred to as a first large diameter portion 7a, and a copper tube having an inner diameter of about 47 mm is referred to as a second large diameter portion 7b. That is, the volume is increased by making the inner diameter of the refrigerant pipe 7 larger than that of the refrigerant pipe 6 as a whole.

Further, the first large diameter portion 7a having an inner diameter of about 30 mm, which is relatively easy to bend, is used as a bent portion of the refrigerant pipe 7, and the second large diameter portion 7b having an inner diameter of about 47 mm, which is difficult to be bent, is directly connected to the refrigerant pipe 7. The use of the pipe portion facilitates the manufacture of the refrigerant pipe 7. The copper pipe used for the 1st large diameter part 7a and the 2nd large diameter part 7b of the refrigerant | coolant pipe | tube 7 can be manufactured at low cost by using the standard goods near the above-mentioned internal diameter.
By configuring the refrigerant pipe 7 as described above, the volume of the refrigerant pipe 7 becomes approximately 1 L larger than the volume of the refrigerant pipe 6, and surplus refrigerant can be stored in the refrigerant pipe 7.

Next, the operation | movement operation | movement in this refrigeration cycle apparatus 100 is demonstrated using FIG.
First, the cooling operation (cooling operation) for cooling the utilization side heat medium flowing into the second plate heat exchanger 5 that is the utilization side heat exchanger will be described with reference to FIG.
The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the first plate heat exchanger 3 that functions as a condenser via the four-way valve 2 and dissipates heat to the heat source water that is the heat source side heat medium. Condensed and liquefied. The high-pressure liquid refrigerant that has flowed out of the first plate heat exchanger 3 is reduced in pressure by the expansion valve 4 to become a low-pressure two-phase refrigerant, and flows into the second plate heat exchanger 5 that functions as an evaporator via the refrigerant pipe 6. . In the 2nd plate type heat exchanger 5, it absorbs heat from the cold water which is a utilization side heat medium, is evaporated and gasified, water is cooled, and cold water is produced | generated. The low-pressure gas refrigerant that has flowed out of the second plate heat exchanger 5 is sucked into the compressor 1.

Here, in the first plate heat exchanger 3 that is the heat source side heat exchanger, for example, heat source water at 25 ° C. flows into the heat medium flow path 3B and is heated by the refrigerant flowing through the refrigerant flow path 3A to increase the temperature. For example, it flows out at 30 ° C.
On the other hand, in the second plate type heat exchanger 5 that is a use side heat exchanger, for example, 12 ° C. cold water flows into the heat medium flow path 5B, and is cooled by the refrigerant flowing through the refrigerant flow path 5A to decrease the temperature. For example, it flows out at 7 ° C. The cold water that has flowed out of the refrigeration cycle apparatus 1 flows into a fan coil (not shown), which is a use side device, and the temperature of the cold water itself rises, for example, to 12 ° C. by cooling the air in the air-conditioned room. After that, it flows into the refrigeration cycle apparatus 1 again.
At this time, in both the first plate heat exchanger 3 and the second plate heat exchanger 5, the refrigerant flowing through the refrigerant flow paths 3A and 5A and the heat medium flowing through the heat medium flow paths 3B and 5B are opposed to each other. Become. As a result, heat exchange performance is improved, and efficient operation is possible.

Next, a heating operation (heating operation) for heating the utilization side heat medium flowing into the second plate heat exchanger 5 that is the utilization side heat exchanger will be described with reference to FIG.
The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the second plate heat exchanger 5 functioning as a condenser via the four-way valve 2 and dissipates heat by heating the hot water that is the use-side heat medium. Then condensed and liquefied. The high-pressure liquid refrigerant that has flowed out of the second plate heat exchanger 5 is decompressed by the expansion valve 4 to become a low-pressure two-phase refrigerant, and flows into the first plate heat exchanger 3 that functions as an evaporator. The first plate heat exchanger 3 evaporates and gasifies by absorbing heat from the heat source water that is the heat source side heat medium, and cools the heat source water. The low-pressure gas refrigerant that has flowed out of the first plate heat exchanger 3 is sucked into the compressor 1.

Here, in the 2nd plate type heat exchanger 5 which is a utilization side heat exchanger, 40 degreeC warm water flows in into the heat-medium flow path 5B, for example, is heated with the refrigerant | coolant which flows through the refrigerant flow path 5A, and temperature rises. For example, it flows out at 45 ° C.
The warm water that has flowed out of the refrigeration cycle apparatus 1 flows into a fan coil that is a use side device, for example, the temperature of the warm water itself is lowered by heating the air in the air-conditioned room, for example, after being lowered to 40 ° C., It flows into the refrigeration cycle apparatus 1 again.
On the other hand, in the first plate heat exchanger 3 that is the heat source side heat exchanger, for example, heat source water at 12 ° C. flows into the heat medium flow path 3B, and is cooled by the refrigerant flowing through the refrigerant flow path 3A to lower the temperature. For example, it flows out at 7 ° C.
At this time, in both the first plate heat exchanger 3 and the second plate heat exchanger 5, the refrigerant flowing through the refrigerant flow paths 3A and 5A and the heat medium flowing through the heat medium flow paths 3B and 5B are in parallel flow. Become. In the parallel flow during the heating operation as compared with the counter flow during the cooling operation, the heat exchange performance of the plate heat exchanger is reduced, so that the refrigerant circulation amount of the refrigeration cycle apparatus 1 is reduced and the amount of surplus refrigerant is increased. . The surplus refrigerant accumulates in the refrigerant flow path 5A of the second plate heat exchanger 5 which is a condenser as a liquid refrigerant, so that the heat exchange performance is further deteriorated.

Therefore, in this embodiment, the volume of the refrigerant pipe 7 between the four-way valve 2 and the second plate heat exchanger 5 is set to the volume of the refrigerant pipe 6 between the four-way valve 2 and the first plate heat exchanger 3. The liquid refrigerant is accumulated in the refrigerant pipe 7 so as to be larger than the above.
Thereby, since it can prevent that a liquid refrigerant accumulates in the 2nd plate type heat exchanger 5 which functions as a condenser, heating operation can be performed, without further worsening the heat exchange performance deterioration by parallel flow.

  Further, since the surplus refrigerant can be stored in the refrigerant pipe 7, a space for providing an accumulator and a receiver tank becomes unnecessary, and the refrigeration cycle apparatus that can suppress an increase in cost without increasing the size of the refrigeration cycle apparatus. Can be provided.

  In the above-described embodiment, the volume of the refrigerant pipe 7 is larger than that of the refrigerant pipe 6. However, depending on the temperature zone of the cold / hot water used in the usage-side equipment and the temperature zone of the heat source water, the refrigerant pipe is more than the refrigerant pipe 7. The capacity of the refrigerant pipe 6 and the refrigerant pipe 7 may be set to the same volume when the volume of 6 may be increased, or when excess refrigerant is not generated.

  As mentioned above, although embodiment of this invention was described, the above-mentioned embodiment is shown as an example and is not intending limiting the range of embodiment. The novel embodiment can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Four-way valve, 3 ... 1st plate type heat exchanger (heat source side heat exchanger), 4 ... Expansion valve (expansion apparatus), 5 ... 2nd plate type heat exchanger (use side heat exchange) ), 6, 7 ... refrigerant pipe, 7a ... first large diameter portion, 7b ... second large diameter portion, 100 ... refrigeration cycle apparatus

Claims (2)

The compressor, the first plate heat exchanger that exchanges heat between the refrigerant and the heat source side heat medium, the four-way valve, the expansion device, and the second plate type heat exchanger that exchanges heat between the refrigerant and the use side heat medium. And a refrigeration cycle apparatus configured by connecting pipes with refrigerant pipes,
The volume of the refrigerant pipe between the second plate heat exchanger and the expansion device is larger than the volume of the refrigerant pipe between the first plate heat exchanger and the expansion device;
The refrigerant pipe between the second plate heat exchanger and the expansion device has a first large diameter portion having an inner diameter larger than that of the refrigerant pipe between the first plate heat exchanger and the expansion device, The second large diameter portion having a larger inner diameter than the first large diameter portion ,
The first large diameter portion is used for a bent portion of a refrigerant pipe between the second plate heat exchanger and the expansion device, and the second large diameter portion is used for the second plate heat exchanger and the expansion device. A refrigeration cycle apparatus characterized by being used in a straight pipe portion of a refrigerant pipe between the two .   In the refrigeration cycle apparatus, during the cooling operation in which both the first plate heat exchanger and the second plate heat exchanger cool the usage-side heat medium, the refrigerant and the heat medium are counterflowed, The refrigeration cycle apparatus according to claim 1, wherein the refrigerant and the heat medium are in parallel flow during a heating operation for heating the use-side heat medium.

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