Refrigeration cycle device

Abstract

This refrigeration cycle device uses a refrigerant to cool an object of cooling, and comprises a refrigerant circuit having a compressor, a condenser, a cooling port, an indoor expansion valve, and an evaporator, the refrigerant circulating through the compressor, the condenser, the cooling port, the indoor expansion valve, and the evaporator in this order. The cooling port has a cooling inlet port through which the refrigerant flows in, and a cooling outlet port through which the refrigerant flows out. The refrigeration cycle device is configured such that it is possible to select between a first formation, in which connection piping is connected to the cooling inlet port and the cooling outlet port, and a second formation, in which a first passage of a cooling heat exchanger is connected to the cooling inlet port and the cooling outlet port, said cooling heat exchanger comprising the first passage, through which the refrigerant passes, and a second passage, through which an external medium passes.

Description

Refrigeration cycle equipment

[0001] The present disclosure relates to a refrigeration cycle device.

[0002] For example, Patent Document 1 discloses a refrigeration cycle device that includes a compressor, a condenser, a receiver, an expansion valve, an accumulator, and a circulation flow path through which a refrigerant circulates through an evaporator, and an injection flow path that branches off from the circulation flow path.

[0003] In refrigeration cycle devices used for refrigeration or freezing, which have a relatively low evaporation temperature, condensation is performed by an air-cooled heat exchanger, but it is known that when the outside air temperature is high, the temperature difference with the outside air temperature cannot be secured, and the condensation capacity and refrigeration capacity tend to decrease. Recently, natural refrigerants are sometimes used to reduce the global warming potential (GWP), and among them, CO ２ This tendency is particularly pronounced when refrigerants are used, reducing the heat rejection capacity of the gas cooler, which can lead to significant capacity loss and high pressure buildup, limiting the performance of the cycle.

[0004] To address these issues, it has been proposed to spray water on the air-cooled heat exchanger or air heat exchanger, thereby utilizing the latent heat of vaporization to lower the intake temperature of the air-cooled heat exchanger and improve performance.

[0005] JP 2019-82294 A

[0006] The above-mentioned water spraying is carried out by supplying water to a spray nozzle installed on the air heat exchanger, but spraying water directly onto an air heat exchanger made of aluminum or other materials can induce metal corrosion due to the water quality or airborne substances. Also, while water spraying can be very effective by utilizing the latent heat of evaporation of water, in hot and humid seasons or environments, the humidity is high and the difference between the wet-bulb temperature and the dry-bulb temperature is small, so the effect of the latent heat of evaporation cannot be obtained and only the effect of sensible heat due to changes in water temperature can be obtained.

[0007] As a way to compensate for the condensation capacity, a Q-UP system can be adopted, in which a separate small-capacity heat source unit is used to cool the liquid piping at the heat source unit outlet, but this is very expensive compared to sprinkler equipment, and it becomes a wasteful piece of equipment when it is not needed during winter, etc. It also tends to be excessive for small-capacity refrigeration and freezing equipment, making it a difficult system to handle.

[0008] In addition, in Patent Document 1, the refrigerant is cooled by a separate refrigeration cycle device in the piping where it is transported from the outdoor unit to the load device. However, at this cooling location, the refrigerant temperature has already been lowered to a supercooled state within the outdoor unit. As a result, the refrigerant temperature may fall below room temperature or even below 0°C. Since methods such as circulating water cannot be used, a separate refrigeration cycle device is necessary. This tends to significantly increase costs and installation space compared to water sprinklers.

[0009] An object of the present disclosure is to provide a refrigeration cycle device that can efficiently compensate for a decrease in condensation capacity at high outdoor temperatures.

[0010] The refrigeration cycle device according to the present disclosure is a refrigeration cycle device that cools an object to be cooled using a refrigerant, and includes a compressor, a condenser, a cooling port, an indoor expansion valve, and an evaporator. The refrigerant is provided with a refrigerant circuit in which the refrigerant circulates through the compressor, the condenser, the cooling port, the indoor expansion valve, and the evaporator in this order. The cooling port has a cooling inlet port through which the refrigerant flows and a cooling outlet port through which the refrigerant flows. The refrigeration cycle device is configured to be selectable between a first form in which connecting pipes are connected to the cooling inlet port and the cooling outlet port, and a second form in which the first passage of a cooling heat exchanger, which has a first passage through which the refrigerant flows and a second passage through which an external medium flows, is connected to the cooling inlet port and the cooling outlet port.

[0011] According to the refrigeration cycle device of the present disclosure, the cooling port can be connected to either the first or second configuration, and in the second configuration, the refrigerant that has passed through the condenser can be cooled by an external medium, thereby efficiently compensating for the decrease in condensation capacity at high outside temperatures.

[0012] FIG. 1 is a refrigerant circuit diagram of a refrigeration cycle device according to a first embodiment of the present disclosure. FIG. 2 is a refrigerant circuit diagram illustrating a cooling unit connected to the refrigeration cycle device according to the first embodiment of the present disclosure. FIG. 3 is a flowchart illustrating control of the refrigeration cycle device according to the first embodiment of the present disclosure. FIG. 4 is a side view of a cooling port of the refrigeration cycle device according to the first embodiment of the present disclosure. FIG. 5 is an exploded view of the cooling port of the refrigeration cycle device according to the first embodiment of the present disclosure. FIG. 6 is an exploded view of the cooling port of the refrigeration cycle device according to the first embodiment of the present disclosure. FIG. 7 is a side view illustrating a process of changing the connection destination of the cooling port of the refrigeration cycle device according to the first embodiment of the present disclosure. FIG. 8 is a side view illustrating a process of changing the connection destination of the cooling port of a refrigeration cycle device according to the first embodiment of the present disclosure. FIG. 9 is a perspective view illustrating a piping path of the cooling port of the refrigeration cycle device according to the first embodiment of the present disclosure. FIG. 10 is a refrigerant circuit diagram illustrating a cooling unit of a refrigeration cycle device according to a first modification of the first embodiment of the present disclosure. FIG. 11 is a refrigerant circuit diagram illustrating a cooling unit of a refrigeration cycle device according to a second modification of the first embodiment of the present disclosure. FIG. 12 is a refrigerant circuit diagram of a refrigeration cycle device according to the second embodiment of the present disclosure. FIG. 13 is a refrigerant circuit diagram of a refrigeration cycle device according to a third embodiment of the present disclosure. FIG. 14 is a refrigerant circuit diagram of a refrigeration cycle device according to a modification of the third embodiment of the present disclosure.

[0013] Embodiments of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to the following embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure. Furthermore, the present disclosure includes all possible combinations of the configurations shown in the following embodiments. In particular, the combinations of components are not limited to those in each embodiment; components described in one embodiment can be applied to another embodiment. The configurations shown in the drawings are merely examples of the configurations of the present disclosure, and the present disclosure is not limited to the configurations shown in the drawings. In the following description, directional terms (e.g., "up," "down," "right," "left," "front," "rear," etc.) are used as appropriate to facilitate understanding, but these are for explanatory purposes and do not limit the present disclosure. In each drawing, components designated with the same reference numerals are identical or equivalent, and this applies throughout the entire specification. The relative dimensional relationships or shapes of the components in each drawing may differ from those in actuality.

[0014] Embodiment 1. <Configuration of Refrigeration Cycle Apparatus 1> Fig. 1 is a refrigerant circuit diagram of a refrigeration cycle apparatus 1 according to embodiment 1 of the present disclosure. Fig. 2 is a refrigerant circuit diagram illustrating a cooling unit 4 connected to the refrigeration cycle apparatus 1 according to embodiment 1 of the present disclosure. As shown in Figs. 1 and 2 , the refrigeration cycle apparatus 1 includes an outdoor unit 2, a load device 3, a cooling unit 4, a first extension pipe 5, and a second extension pipe 6, and constitutes a refrigerant circuit C1 and an injection circuit C2. The refrigeration cycle apparatus 1 is configured to cool an object to be cooled using a refrigerant.

[0015] The refrigerant circuit C1 is composed of components including a compressor 21, a condenser 22, a cooling port 20, an outdoor expansion valve 24, a pressure relief device 25, a liquid reservoir 26, a subcooling heat exchanger 27, a first extension pipe 5, an indoor expansion valve 31, an evaporator 32, and a second extension pipe 6. The refrigerant circuit C1 can be connected to the cooling unit 4 at the cooling port 20. The components of the refrigerant circuit C1 are connected in a ring shape by a refrigerant pipe 1A.

[0016] The injection circuit C2 branches off from the refrigerant circuit C1 between the subcooling heat exchanger 27 and the first extension pipe 5, and is connected to the intermediate port of the compressor 21 or the high-stage suction portion of the two-stage compressor.

[0017] The outdoor unit 2 is the outdoor unit 2 of the refrigeration cycle apparatus 1 configured to be connected to the load device 3. The outdoor unit 2 includes a compressor 21, a condenser 22, a cooling port 20, an outdoor expansion valve 24, a pressure relief device 25, a liquid reservoir 26, a subcooling heat exchanger 27, and an injection adjustment valve 28. The outdoor unit 2 also includes an outdoor fan 23 that generates an airflow that passes through the condenser 22.

[0018] The compressor 21 draws in low-temperature and low-pressure refrigerant, compresses it, and discharges it as high-temperature and high-pressure refrigerant. The compressor 21 may be one whose capacity, i.e., the amount of refrigerant delivered per unit time, can be changed by, for example, arbitrarily changing the drive frequency using an inverter circuit (not shown) or the like.

[0019] The condenser 22 is configured so that the high-temperature, high-pressure gas refrigerant discharged from the compressor 21 exchanges heat with outside air, i.e., dissipates heat to the outside air. The condenser 22 performs air cooling and is, for example, an air heat exchanger. In the condenser 22, the gas refrigerant exchanges heat with the outside air, thereby reducing the enthalpy of the refrigerant.

[0020] The outdoor expansion valve 24, which is an electronic expansion valve capable of reducing the pressure of the refrigerant after it leaves the condenser 22 and flows into the load device 3, is configured to reduce the pressure of the refrigerant by one stage. The pressure relief device 25 releases the refrigerant when a certain pressure is reached at the connection point. The liquid reservoir 26 is a container for storing excess refrigerant from the refrigeration cycle device 1. The subcooling heat exchanger 27 has a first subcooling passage B1 and a second subcooling passage B2 and is configured to exchange heat between the refrigerant flowing through the first subcooling passage B1 and the refrigerant flowing through the second subcooling passage B2. The subcooling heat exchanger 27 subcools the liquid refrigerant from the liquid reservoir 26.

[0021] The injection adjustment valve 28 adjusts the flow rate of refrigerant branched from the refrigerant circuit C1 to the injection circuit C2. The refrigerant that has passed through the injection adjustment valve 28 passes through a second subcooling passage B2 of the subcooling heat exchanger 27 and is injected into an intermediate port of the compressor 21. The amount of refrigerant that passes through the injection adjustment valve 28 is adjusted by feedback control of the temperature of the refrigerant discharged from the compressor 21. If the compressor 21 is a two-stage compressor, the refrigerant that has passed through the injection adjustment valve 28 may be injected into a high-stage suction section.

[0022] The cooling port 20 has an inlet port 201 and an outlet port 202. The inlet port 201 and the outlet port 202 are examples of a cooling inlet port and a cooling outlet port, respectively. The cooling port 20 is configured so that its connection can be switched between the cooling unit 4 and the connection pipe 15. A first configuration is when the cooling port 20 is connected to the connection pipe 15, and a second configuration is when the cooling port 20 is connected to the cooling unit 4. By switching the connection of the cooling port 20, it is possible to select whether or not the refrigerant output from the condenser 22 flows through the first cooling passage H1 of the cooling heat exchanger 41 of the cooling unit 4.

[0023] The cooling unit 4 includes a cooling heat exchanger 41 having a first cooling passage H1 and a second cooling passage H2. The cooling heat exchanger 41 exchanges heat between the refrigerant flowing into the first cooling passage H1 from the refrigerant circuit C1 and an external medium flowing through the second cooling passage H2. The first cooling passage H1 is connected to the inlet port 201 and the outlet port 202 of the cooling port 20 of the refrigerant circuit C1 via a first inlet pipe 44 and a first outlet pipe 45, respectively. The second cooling passage H2 is connected to a circuit through which the external medium flows via a second inlet pipe 42 and a second outlet pipe 43. The external medium is, for example, tap water, and the second cooling passage H2 is connected to, for example, a water pipe 47, which circulates water. The water from the water pipe 47 flows into the second cooling passage H2 from the second inlet pipe 42 and is discharged via the second outlet pipe 43. A flow control valve 46 is disposed in the second inlet pipe 42. The flow control valve 46 adjusts the flow rate of the external medium flowing through the second cooling passage H2. By controlling the opening degree of the flow control valve 46, for example, during high outside temperatures, the required amount of external medium can be supplied to cool the refrigerant. The opening degree of the flow control valve 46 is controlled by a signal from the external control device 200 so that the minimum amount of tap water required is drained. By connecting the cooling unit 4 to the cooling port 20, multiple means can be selected to suppress a decrease in condensing capacity during high outside temperatures.

[0024] The load device 3 includes an indoor expansion valve 31 and an evaporator 32. The load device 3 is provided with an indoor fan 33 for sending air to the evaporator 32. The evaporator 32 performs heat exchange between the air in the space to be cooled and the refrigerant. The evaporator 32 evaporates the refrigerant by absorbing heat from the air in the space to be cooled. The indoor expansion valve 31 is an electronic expansion valve that can reduce the pressure of the refrigerant. Note that the indoor expansion valve 31 may be, for example, a thermostatic expansion valve that is controlled independently for the outdoor unit 2 and the load device 3.

[0025] Here, the refrigerant used in the refrigerant circuit C1 of the refrigeration cycle device 1 is, for example, CO ２ However, if it is difficult to ensure the degree of supercooling, other refrigerants may be used.

[0026] For ease of explanation, the following will be described using CO in a supercritical state. ２ When cooling a refrigerant such as a refrigerant, the condenser will also be referred to as the condenser 22. For ease of explanation, the amount of temperature drop from the reference temperature of a refrigerant in a supercritical state will also be referred to as the degree of subcooling.

[0027] The refrigeration cycle apparatus 1 is equipped with various sensors, a control device 100, and an external control device 200. The control device 100 and the external control device 200 are examples of a control unit. The various sensors include, for example, an outside air temperature sensor T1, a condenser outlet temperature sensor T2, a return temperature sensor T3, a second inlet temperature sensor T4, and a second outlet temperature sensor T5.

[0028] The outdoor air temperature sensor T1 is disposed, for example, at the air inlet of the outdoor unit 2 and measures the temperature of the air with which the condenser 22 exchanges heat, i.e., the outdoor air. The condenser outlet temperature sensor T2 is attached, for example, to the refrigerant pipe 1A downstream of the condenser 22 and measures the temperature of the refrigerant flowing downstream of the condenser 22, i.e., the refrigerant exiting the condenser 22. The return temperature sensor T3 is attached, for example, to the first outlet pipe 45 of the cooling unit 4 and measures the temperature of the refrigerant returning from the cooling unit 4 to the refrigerant circuit C1. The second inlet temperature sensor T4 is attached, for example, to the second inlet pipe 42 of the cooling unit 4 and measures the temperature of the refrigerant flowing into the second cooling passage H2 of the cooling heat exchanger 41. The second outlet temperature sensor T5 is attached, for example, to the second outlet pipe 43 of the cooling unit 4 and measures the temperature of the refrigerant flowing out of the second cooling passage H2 of the cooling heat exchanger 41.

[0029] The control device 100 receives data measured by various sensors and controls each actuator of the outdoor unit 2 based on the data. The control device 100 also outputs a first cooling signal or a second cooling signal based on the data measured by the various sensors. The external control device 200 receives the first cooling signal or the second cooling signal output from the control device 100. The external control device 200 controls the flow rate of the external medium flowing through the second cooling passage H2 of the cooling heat exchanger 41 of the cooling unit 4 in accordance with the first cooling signal or the second cooling signal. The external control device 200 adjusts the flow rate of the external medium flowing through the second cooling passage H2, for example, by controlling the opening of the flow rate adjustment valve 46.

[0030] The control device 100 and the external control device 200 are configured by, for example, a CPU (Central Processing Unit, also called a central processing unit, processing device, arithmetic unit, microprocessor, microcomputer, processor, or DSP (Digital Signal Processor)). The control device 100 and the external control device 200 have memory configured with, for example, non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disk), etc. The control device 100 and the external control device 200 realize processing by programs stored in the memory. The control device 100 and the external control device 200 are provided, for example, in the outdoor unit 2 and the cooling unit 4, respectively. The control device 100 and the external control device 200 may be configured as an integrated unit or may be configured separately. The functions of the control device 100 and the external control device 200 may be realized, for example, on a cloud configured to be able to communicate with various sensors or actuators.

[0031] 3 is a flowchart illustrating the control of the refrigeration cycle apparatus 1 according to the first embodiment of the present disclosure. The process shown in FIG. 3 is executed by the control device 100 at a predetermined time interval, for example, every second. First, in step S1, the control device 100 determines whether or not an operation signal for the compressor 21 has been received. The operation signal for the compressor 21 is a signal indicating whether the compressor 21 is operating, and is exchanged between the inverter board of the compressor 21 and the control device 100.

[0032] In step S1, if the control device 100 has not received an operation signal for the compressor 21 (NO in step S1), the control device 100 transitions to normal control. When there is no operation signal for the compressor 21, the compressor 21 is in a standby state where it is not operating. Normal control refers to control that performs processing other than the processing shown in FIG. 3. Therefore, when there is no operation signal for the compressor 21, the control device 100 commands the opening degrees of the various adjustment valves in the standby state or the rotation speed of the outdoor fan 23. Note that the rotation speed of the outdoor fan 23 may be 0 rotations.

[0033] On the other hand, when the control device 100 receives an operation signal for the compressor 21 in step S1 (YES in step S1), the control device 100 proceeds to step S2.

[0034] In step S2, the control device 100 determines whether the operation signal of the compressor 21 has been continuously received for t1 minutes or more, and if not (NO in step S2), the control device 100 transitions to normal control. If the operation signal of the compressor 21 has been continuously received for t1 minutes or more (YES in step S2), the control device 100 transitions to step S3.

[0035] In step S3, the control device 100 determines whether the measurement value of the outside air temperature sensor T1 has been higher than the threshold outside air temperature TA for a period of t2 minutes or more. The state in which the measurement value of the outside air temperature sensor T1 is higher than the threshold outside air temperature TA means that the outside air temperature has exceeded a certain value. If the control device 100 determines in step S3 that the measurement value has been higher than the threshold outside air temperature TA for a period of t2 minutes or more (YES in step S3), the control device 100 proceeds to step S4. If the control device 100 determines that the measurement value has not been higher than the threshold outside air temperature TA, the control device 100 proceeds to step S5.

[0036] In step S5, if the temperature difference between the condenser outlet temperature sensor T2 and the return temperature sensor T3 is smaller than the target temperature difference Tm1, the control device 100 outputs a first cooling signal (cooling signal 1 in FIG. 3) to the outside so that the temperature difference becomes larger than the target temperature difference Tm1 (step S9). The determination of the target temperature difference Tm1 is intended to measure the temperatures at the inlet and outlet and to confirm whether the amount of heat exchanged by the cooling heat exchanger 41 is sufficient.

[0037] In step S4, the control device 100 determines whether the temperature difference between the condenser outlet temperature sensor T2 and the outside air temperature sensor T1 is less than the target temperature difference Tsc. If the temperature difference is less than the target temperature difference Tsc, the control device 100 proceeds to step S6 (YES in step S4). The target temperature difference Tsc is, for example, a value smaller than the target temperature difference Tm1. A state in which the temperature difference is less than the target temperature difference Tsc means that no further heat exchange with the air can be performed in the condenser 22, and the refrigerant temperature detected by the condenser outlet temperature sensor T2 has dropped to approximately the air temperature detected by the outside air temperature sensor T1.

[0038] In step S6, the control device 100 determines whether the return temperature sensor T3 is higher than the target temperature Tm2, ​​and if it is higher than the target temperature Tm2 (YES in step S6), it outputs a second cooling signal (cooling signal 2 in FIG. 3) to the outside so that the value of the return temperature sensor T3 becomes the target temperature Tm2 (step S7). The target temperature Tm2 is used to determine whether cooling to the minimum temperature has been achieved, and if it is the target temperature Tm2, ​​it can be detected that the enthalpy value has sufficiently decreased and the necessary refrigeration capacity has been secured.

[0039] If the result of step S4, step S5, or step S6 is NO, the control device 100 transitions to normal control (steps 8 and 10).

[0040] The first cooling signal or the second cooling signal output from the control device 100 is received by the external control device 200, which controls the flow rate of the external medium passing through the second cooling passage H2 of the cooling heat exchanger 41 of the cooling unit 4 in accordance with the first cooling signal or the second cooling signal. Therefore, the opening of the flow rate adjustment valve 46 of the cooling unit 4 is controlled, and the flow rate of the external medium flowing through the second cooling passage H2 is adjusted.

[0041] Both the first cooling signal and the second cooling signal adjust the flow rate or temperature of the medium passing through the second cooling passage H2 of the cooling heat exchanger 41 to increase the heat exchange amount. The second cooling signal indicates that the required heat exchange amount is greater than the first cooling signal. The first cooling signal and the second cooling signal are ON or OFF signals, and allow the minimum required cooling to be performed in three stages: "no signal," "first cooling signal ON," or "first cooling signal ON." This allows for a simpler response than when the values ​​of various sensors are output directly.

[0042] As described above, the refrigeration cycle apparatus 1 includes a cooling port 20 to which the cooling unit 4 can be connected, and is configured to be able to cool the outlet portion of the condenser 22. For example, if a method is adopted in which the refrigeration capacity is improved by increasing the enthalpy difference by lowering the temperature of the refrigerant flowing into the first extension pipe 5, attempting to cool the portion before the first extension pipe 5 with water may result in the refrigerant temperature falling below 0°C, resulting in the adverse effect of freezing. Being able to cool the outlet portion of the condenser 22, as in the refrigeration cycle apparatus 1, can assist in cases where the performance of the air heat exchanger is reduced due to high outdoor temperatures. Because the temperature of the refrigerant at the outlet portion of the condenser 22 is relatively high due to high pressure, heat exchange can be sufficiently performed even with the water temperature of the water pipe 47, for example.

[0043] Fig. 4 is a side view of the cooling port 20 of the refrigeration cycle apparatus 1 according to the first embodiment of the present disclosure. In Fig. 4, solid arrows indicate the flow of refrigerant. As shown in Fig. 4, the cooling port 20 has an inlet port 201, an outlet port 202, and a connecting pipe 15. The inlet port 201 and the outlet port 202 are arranged so that their axial directions extend parallel to each other. The inlet port 201 and the outlet port 202 face the same direction. The inlet port 201 and the outlet port 202 of the cooling port 20 are pipes with expanded ends.

[0044] The connection pipe 15 is U-shaped and can be connected to an inlet port 201 and an outlet port 202 whose ends extend parallel to each other. The connection pipe 15 is detachably connected to the expanded portions of the inlet port 201 and the outlet port 202.

[0045] Both ends of the connection pipe 15 are fitted into the inlet port 201 and the outlet port 202, respectively, and the connection pipe 15 is connected by being brazed while fitted into the inlet port 201 and the outlet port 202. Note that Fig. 4 does not specify up, down, left, or right.

[0046] In regions where the outside air temperature is low or in environments where the refrigeration capacity becomes excessive, the cooling unit 4 may become an unnecessary function. By providing the cooling port 20, it is possible to select the implementation of cooling by the cooling unit 4. When the cooling unit 4 is not required, a first configuration can be adopted in which the inlet port 201 and the outlet port 202 of the cooling port 20 are connected by the connecting pipe 15. By adopting the first configuration, the refrigeration cycle apparatus 1 can be operated without implementing cooling by the cooling unit 4.

[0047] Fig. 5 is an exploded view of the cooling port 20 of the refrigeration cycle apparatus 1 according to the first embodiment of the present disclosure. Fig. 6 is an exploded view of the cooling port 20 of the refrigeration cycle apparatus 1 according to the first embodiment of the present disclosure, viewed from a different perspective than Fig. 5. Fig. 7 is a side view illustrating a process of changing the connection destination of the cooling port 20 of the refrigeration cycle apparatus 1 according to the first embodiment of the present disclosure.

[0048] 5 to 7 , the cooling port 20 can be disassembled by removing the brazed portions between the inlet port 201 and the outlet port 202 and the connection pipe 15, and the connection pipe 15 can be removed. In the initial state of the cooling port 20, both ends of the connection pipe 15 are connected to the inlet port 201 and the outlet port 202. To change the connection destination of the cooling port 20, first, the brazing is removed at the connection portions between the connection pipe 15 and the inlet port 201 and the outlet port 202, that is, the portions circled with dotted lines in FIG. 7 . As a result, the connection pipe 15 is removed from the inlet port 201 and the outlet port 202.

[0049] Next, the first inlet pipe 44 and the first outlet pipe 45 of the cooling unit 4 are attached by brazing to the inlet port 201 and the outlet port 202 of the cooling port 20 as on-site pipes. At this time, because the inlet port 201 and the outlet port 202 of the cooling port 20 have been expanded, it is sufficient to prepare, for example, a blank pipe as the first inlet pipe 44 and the first outlet pipe 45 of the cooling unit 4. The first inlet pipe 44 and the first outlet pipe 45 of the cooling unit 4 are inserted into the expanded portions of the inlet port 201 and the outlet port 202, completing the connection of the cooling unit 4.

[0050] When changing the connection destination of the cooling port 20, the brazing of the connection pipe 15 can be removed without using a pipe cutter or the like. Since the inlet port 201 and the outlet port 202 from which the connection pipe 15 has been removed have expanded pipe portions, the piping can be routed simply by preparing a blank pipe that can be attached to the inlet port 201 and the outlet port 202.

[0051] 8 is a side view illustrating a process of changing the connection destination of the cooling port 20 of the refrigeration cycle apparatus 1 according to the comparative example. As shown in FIG. 8, in the refrigeration cycle apparatus 1 according to the comparative example, the connection pipe 15 of the cooling port 20 is a straight pipe.

[0052] In this case, the cooling port 20 is initially cut off from the connecting pipe 15 at the inlet port 201 and the outlet port 202 using, for example, a pipe cutter. When the connecting pipe 15 is cut off using, for example, a pipe cutter, the inlet port 201 and the outlet port 202, which serve as connection ports, are cut off. For this reason, it is necessary to expand the first inlet pipe 44 and the first outlet pipe 45 on the cooling unit 4 side, which is the side to which the pipes are attached, which increases the number of construction steps and tools required.

[0053] The cut portion where the connection pipe 15 is cut off is expanded, and the first inlet pipe 44 and the first outlet pipe 45 of the cooling unit 4, which are the on-site pipes, are attached, with the inlet port 201 and the outlet port 202 being arranged opposite each other. For this reason, the cooling unit 4 needs to prepare bent pipes or elbows as the first inlet pipe 44 and the first outlet pipe 45, and connect them to the inlet port 201 and the outlet port 202. In this way, if the connection pipe 15 is a straight pipe, elbows or bent pipes must be prepared to enable connection to the pipes of the cooling unit 4, which is the attached side, and this requires the procurement of parts or tools, which places a burden on the construction process.

[0054] As in embodiment 1, the cooling port 20 is provided with a U-shaped connecting pipe 15, and the connecting pipe 15 is brazed to the inlet port 201 and the outlet port 202, thereby suppressing an increase in the number of construction steps and tools and reducing the burden of the construction step.

[0055] 9 is a perspective view illustrating the piping path of the cooling port 20 of the refrigeration cycle apparatus 1 according to the first embodiment of the present disclosure. As shown in FIG. 9 , the inlet port 201 and the outlet port 202 of the cooling port 20 can be configured in any of modes (a) to (d), for example. That is, the inlet port 201 and the outlet port 202 of the cooling port 20 only need to have their axial directions parallel to each other so that the U-shaped connecting pipe 15 can be connected. The inlet port 201 and the outlet port 202 extend with their axial directions parallel to each other, allowing for flexible routing of the pipes in the outdoor unit 2.

[0056] 10 is a refrigerant circuit diagram illustrating a cooling unit 4 of a refrigeration cycle apparatus 1 according to a first modification of the first embodiment of the present disclosure. As shown in FIG. 10 , the cooling unit 4 has a tank 48 and a pump 49 connected to a second outlet pipe 43.

[0057] The tank 48 stores the external medium. The pump 49 adjusts the flow rate of the external medium flowing through the second cooling passage H2. By adjusting the flow rate of the external medium transported by the pump 49, for example, it is possible to supply a necessary amount of water to cool the refrigerant during high outside temperatures. The external medium is, for example, chilled water produced in another refrigeration system. The second cooling passage H2, together with the second inlet pipe 42 and the second outlet pipe 43, constitutes a chilled water circuit C3 of the other refrigeration system.

[0058] <Modification 2> FIG. 11 is a refrigerant circuit diagram illustrating the cooling unit 4 of the refrigeration cycle apparatus 1 according to Modification 2 of the first embodiment of the present disclosure. As shown in FIG. 11 , the second cooling passage H2 of the cooling unit 4 may be connected to a cooling refrigerant circuit C4 through which a second refrigerant flows as an external medium. The cooling refrigerant circuit C4 is connected to a cooling compressor 210, a second cooling heat exchanger 220, a cooling expansion valve 240, and a cooling outdoor fan 230. In other words, the cooling unit 4 may have a dual-circuit configuration using a cooling refrigeration cycle. For example, when water cooling is not suitable due to water conditions such as poor local water quality, or when little cooling is required, a cooling refrigeration cycle can be connected as the cooling unit 4 to cool the refrigerant in the refrigerant circuit C1. Note that the cooling refrigerant circuit C4 may use, for example, a refrigerant with a different boiling point than the refrigerant flowing through the refrigerant circuit C1. Furthermore, a small-capacity heat source can be used as the cooling refrigeration cycle.

[0059] The refrigeration cycle apparatus 1 according to the first embodiment described above can select between a first configuration in which the connection pipes 15 are connected to the inlet port 201 and the outlet port 202 of the refrigerant circuit C1, and a second configuration in which the connection pipes 15 are connected to the cooling heat exchanger 41 of the cooling unit 4. Selecting the first configuration allows the circuit to operate as is without compensating for a decrease in condensing capacity using the cooling unit 4. Selecting the second configuration allows the refrigerant to exchange heat with an external medium in the cooling heat exchanger 41, thereby cooling the refrigerant flowing out of the condenser 22. This effectively compensates for a decrease in condensing capacity during high outdoor temperatures. Furthermore, water spraying or the like is no longer necessary, reducing concerns about corrosion of the condenser 22. Furthermore, whether or not cooling by the cooling heat exchanger 41 is realized can be selected by attaching or detaching the cooling unit 4 to the cooling port 20.

[0060] Furthermore, the cooling unit 4 is connected to the inlet port 201 and the outlet port 202 by removing the U-shaped connecting pipe 15. If the inlet port 201 and the outlet port 202 were connected by a straight pipe, when cooling is selected, it would be necessary to prepare an elbow or bent pipe to connect the cooling unit 4. On the other hand, since the inlet port 201 and the outlet port 202 are connected by the U-shaped connecting pipe 15, when cooling is selected, it is not necessary to procure parts or tools for connecting the cooling port 20, thereby reducing the burden of the construction process.

[0061] Furthermore, the inlet port 201 and the outlet port 202 have expanded shapes so that they fit onto both ends of the connecting pipe 15. When connecting the cooling unit 4, the brazing on the connecting pipe 15 is removed, and the connection can be handled simply by attaching a blank pipe to the expanded portions of the inlet port 201 and the outlet port 202, without using a pipe cutter or the like. Pipe expansion is not required on the pipe side where the inlet port 201 and the outlet port 202 are attached, either, which reduces the need for additional construction steps or tools.

[0062] The control device 100 is also configured to output a cooling signal based on the condenser outlet temperature sensor T2 and the outside air temperature sensor T1 so that the temperature of the return temperature sensor T3 reaches a target value. That is, the control device 100 controls the temperature difference between the condenser outlet temperature sensor T2 and the return temperature sensor T3 using a first cooling signal so that it is greater than the target temperature difference Tm1. Alternatively, the control device 100 controls the value of the return temperature sensor T3 using a second cooling signal so that it reaches the target temperature Tm2. This further cools the refrigerant flowing out of the condenser 22 in the cooling unit 4, thereby compensating for a decrease in the condensing capacity of the condenser 22 during high outside air temperatures.

[0063] Between the outlet port 202 and the indoor expansion valve 31, the outdoor expansion valve 24, the pressure relief device 25, the liquid storage container 26, and the subcooling heat exchanger 27 may be connected in this order by the refrigerant piping 1A.

[0064] In addition to the refrigerant circuit C1, an injection circuit C2, which circulates a portion of the refrigerant that has passed through the subcooling heat exchanger 27, injects the refrigerant into the compressor 21. This reduces the discharge pressure of the compressor 21, increases the heat exchange efficiency in the condenser 22 when the outside air temperature is high, and improves the condensing capacity of the condenser 22.

[0065] Embodiment 2. Fig. 12 is a refrigerant circuit diagram of a refrigeration cycle apparatus 1 according to embodiment 2 of the present disclosure. The refrigeration cycle apparatus 1 according to embodiment 2 differs from embodiment 1 in that a cooling unit 4 is provided in the outdoor unit 2. In embodiment 2, parts common to embodiment 1 are assigned the same reference numerals and description thereof will be omitted, and the description will focus on differences from embodiment 1.

[0066] 12 , the external medium flowing through the second cooling passage H2 of the cooling unit 4 flows in from the first connecting pipe port 7 of the outdoor unit 2 and flows out from the second connecting pipe port 8. The measurement values ​​of the second inlet temperature sensor T4 and the second outlet temperature sensor T5 of the second cooling passage H2 are recognized by the control device 100.

[0067] For example, water powered by the water pressure of a water pipe 47 (see FIG. 2 ) flows through the first connection pipe port 7 and the second connection pipe port 8. For example, a water circuit circulated by a pump 49 (see FIG. 10 ) is connected to the first connection pipe port 7 and the second connection pipe port 8. For example, a refrigerant from another refrigeration device may flow through the first connection pipe port 7 and the second connection pipe port 8. In this case, the cooling heat exchanger 41 functions as an evaporator to cool the refrigerant.

[0068] According to the refrigeration cycle apparatus 1 of the second embodiment described above, the cooling unit 4 is built into the outdoor unit 2, eliminating the need to replace the connecting pipe 15 and allowing the unit to be handled as a single unit, thereby reducing the workload. Furthermore, by recognizing the measured values ​​of the second inlet temperature sensor T4 and the second outlet temperature sensor T5 of the second cooling passage H2 in the control device 100, a control signal that reflects feedback on a more transient state can be output to the external control device 200. This reduces the amount of water used or the operating rate of the pump 49, thereby saving energy.

[0069] Embodiment 3. Figure 13 is a refrigerant circuit diagram of a refrigeration cycle apparatus 1 according to embodiment 3 of the present disclosure. The refrigeration cycle apparatus 1 according to embodiment 3 differs from embodiments 1 and 2 in that the refrigerant circuit C1 does not perform two-stage expansion. In embodiment 3, parts common to embodiments 1 and 2 are assigned the same reference numerals and description thereof will be omitted, and the description will focus on differences from embodiments 1 and 2.

[0070] As shown in FIG. 13 , the outdoor unit 2 includes a compressor 21, a condenser 22, an air-cooled subcooling heat exchanger 29, a liquid reservoir 26, a pressure relief device 25 installed in the liquid reservoir 26, a subcooling heat exchanger 27, and an injection adjustment valve 28. The outdoor unit 2 is configured to be connected to a load device 3 via a first extension pipe 5 and a second extension pipe 6. The refrigerant circuit C1 does not have a two-stage expansion circuit. A fluorocarbon refrigerant, propane, or the like can be used as the refrigerant. The subcooling heat exchanger 27 has a first subcooling passage B1 and a second subcooling passage B2, and is configured to exchange heat between the refrigerant flowing through the first subcooling passage B1 and the refrigerant flowing through the second subcooling passage B2.

[0071] The inlet port 201 and the outlet port 202 are disposed between the air-cooled subcooling heat exchanger 29 and the subcooling heat exchanger 27. The cooling unit 4 is connected to the inlet port 201 and the outlet port 202 and is built into the outdoor unit 2.

[0072] The air-cooled subcooling heat exchanger 29 can cool the refrigerant from the liquid reservoir 26 to a temperature equivalent to the outside air temperature. When the outside air temperature is high, a decrease in condensation capacity is expected, but the cooling heat exchanger 41 of the cooling unit 4 is installed downstream of the air-cooled subcooling heat exchanger 29, and the refrigerant that flows out of the condenser 22 is cooled by the refrigerant exchanging heat with an external medium in the cooling unit 4. Therefore, the same effect as in the first embodiment can be achieved, that is, when the outside air temperature is high, the condensation capacity can be compensated for and the risk of corrosion of the condenser 22 can be reduced.

[0073] <Modification> Figure 14 is a refrigerant circuit diagram of a refrigeration cycle apparatus 1 according to a modification of the third embodiment of the present disclosure. As shown in Figure 14, in a circuit configuration in which two-stage expansion is not performed in the refrigerant circuit C1, the connection pipe 15 connecting the inlet port 201 and the outlet port 202 may be configured to be interchangeable with the cooling unit 4. In this case, too, the refrigerant exchanges heat with an external medium in the cooling unit 4, thereby cooling the refrigerant flowing out of the condenser 22, thereby achieving the effect of compensating for condensation capacity and reducing concerns about corrosion of the condenser 22 at high outside air temperatures.

[0074] According to the refrigeration cycle device 1 of embodiment 2 described above, since the cooling heat exchanger 41 is connected to the outlet portion of the air-cooled subcooling heat exchanger 29, the number of expansion valves can be reduced when, for example, a fluorocarbon refrigerant or propane is used as the refrigerant.

[0075] In addition, since a cooling unit 4 can be connected to the outlet portion of the air-cooled subcooling heat exchanger 29, if there is no concern about high outside temperatures, the cooling unit 4 can be omitted, or the cooling unit 4 can be installed as needed.

[0076] It should be noted that Embodiments 1 to 3 can be combined as appropriate. Furthermore, Embodiments 1 to 3 should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0077] 1 Refrigeration cycle device, 1A refrigerant piping, 2 outdoor unit, 3 load device, 4 cooling unit, 5 first extension piping, 6 second extension piping, 7 first connection piping port, 8 second connection piping port, 15 connection piping, 20 cooling port, 21 compressor, 22 condenser, 23 outdoor fan, 24 outdoor expansion valve, 25 pressure relief device, 26 liquid reservoir, 27 subcooling heat exchanger, 28 injection adjustment valve, 29 air-cooled subcooling heat exchanger, 31 indoor expansion valve, 32 evaporator, 33 indoor fan, 41 cooling heat exchanger, 42 second inlet piping, 43 second outlet piping, 44 first inlet piping, 45 first outlet piping, 46 flow rate adjustment valve, 47 water pipe, 48 tank, 49 pump, 100 control device, 200 external control device, 201 inlet port, 202 Outlet port, 210 cooling compressor, 220 cooling second heat exchanger, 230 cooling outdoor fan, 240 cooling expansion valve, B1 subcooling first passage, B2 subcooling second passage, C1 refrigerant circuit, C2 injection circuit, C3 chilled water circuit, C4 cooling refrigerant circuit, H1 cooling first passage, H2 cooling second passage, T1 outside air temperature sensor, T2 condenser outlet temperature sensor, T3 return temperature sensor, T4 second inlet temperature sensor, T5 second outlet temperature sensor, TA threshold outside air temperature.

Claims

1. A refrigeration cycle device that uses a refrigerant to cool an object, the refrigerant circuit having a compressor, a condenser, a cooling port, an indoor expansion valve, and an evaporator, the refrigerant circulating through the compressor, the condenser, the cooling port, the indoor expansion valve, and the evaporator in that order, the cooling port having a cooling inlet port through which the refrigerant flows and a cooling outlet port through which the refrigerant flows, the refrigeration cycle device being configured to be selectable between a first form in which connecting piping is connected to the cooling inlet port and the cooling outlet port, and a second form in which the first passage of a cooling heat exchanger is connected to the cooling inlet port and the cooling outlet port, the first passage having a first passage through which the refrigerant flows and a second passage through which an external medium flows.

2. The refrigeration cycle device according to claim 1, further comprising a cooling unit accommodating the cooling heat exchanger, wherein in the second configuration, the cooling unit is connected to the cooling inlet port and the cooling outlet port.

3. The refrigeration cycle device according to claim 1 or 2, wherein the cooling inlet port and the cooling inlet port are expanded so as to fit onto both ends of the connecting pipe.

4. A refrigeration cycle device according to any one of claims 1 to 3, comprising: a condenser outlet temperature sensor that measures the temperature of the refrigerant flowing through the outlet portion of the condenser; an outside air temperature sensor that measures the outside air temperature; a return temperature sensor that measures the temperature of the refrigerant returning from the cooling heat exchanger to the refrigerant circuit; and a control unit that outputs a cooling signal based on the condenser outlet temperature sensor and the outside air temperature sensor so that the temperature of the return temperature sensor reaches a target value.

5. The refrigeration cycle device according to claim 4, further comprising a flow rate adjustment valve for controlling the flow rate of the external medium, wherein the control unit controls the opening degree of the flow rate adjustment valve based on the condenser outlet temperature sensor and the outside air temperature sensor.

6. The refrigeration cycle device according to claim 4, further comprising a pump that controls the flow rate of the external medium, wherein the control unit controls the flow rate of the external medium transported by the pump based on the condenser outlet temperature sensor and the outside air temperature sensor.

7. A refrigeration cycle device according to any one of claims 1 to 6, further comprising an outdoor expansion valve, a pressure relief device, a liquid storage container, and a subcooling heat exchanger connected to the refrigerant circuit, wherein the outdoor expansion valve, the pressure relief device, the liquid storage container, and the subcooling heat exchanger are connected in this order between the cooling outlet port and the indoor expansion valve.

8. The refrigeration cycle device according to claim 7, further comprising an injection circuit for returning a portion of the refrigerant that has passed through the subcooling heat exchanger to the compressor.

9. A refrigeration cycle device according to any one of claims 1 to 8, comprising an outdoor unit accommodating the compressor, the condenser, and the cooling port, wherein the cooling heat exchanger is built into the outdoor unit in a state where it is connected to the cooling inlet port and the cooling outlet port.

10. A refrigeration cycle device as claimed in any one of claims 1 to 6, further comprising a liquid storage container, a pressure relief device, and an air-cooled subcooling heat exchanger connected to the refrigerant circuit, wherein the liquid storage container, the pressure relief device, and the air-cooled subcooling heat exchanger are connected in this order, and the cooling heat exchanger is connected to the outlet portion of the air-cooled subcooling heat exchanger.

11. A refrigeration cycle device according to any one of claims 1 to 6, further comprising a liquid storage container connected to the refrigerant circuit, a pressure relief device, and an air-cooled subcooling heat exchanger, wherein the liquid storage container, the pressure relief device, and the air-cooled subcooling heat exchanger are connected in this order between the condenser and the cooling inlet port, and the cooling heat exchanger can be connected to the outlet portion of the air-cooled subcooling heat exchanger.

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