Flow Path Unit and Refrigerant Circulation Device

The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2024-072917, filed on Apr. 26, 2024, the entire contents of which are hereby incorporated herein by reference.

The present disclosure relates to flow path assemblies and refrigerant circulation devices.

A known refrigerant circulation device cools a cooling target by transmitting, to a circulating refrigerant, heat received from the cooling target.

An example embodiment of the present disclosure is directed to a flow path assembly including a main body, a first tubular body, and a sensor. The main body includes a flow path continuous with each of a first opening and a second opening. The first tubular body extends in a first direction intersecting the first opening in the flow path. A plurality of holes are provided in the first tubular body. The sensor detects a pressure in the first tubular body. A first end of the first tubular body in the first direction is connected to the first opening. The sensor is closer to a second end of the first tubular body than the first end of the first tubular body.

Another example embodiment of the present disclosure is directed to a refrigerant circulation device including the flow path assembly at a refrigerant inflow port.

The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.

Hereinafter, example embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numeral and description thereof will not be repeated.

In, a cooling systemincludes, as constituent elements, a refrigerant circulation device (hereinafter, also referred to as “CDU”), a distribution manifold, a collection manifold, at least one cold plate, a cooling device, and flow pathsand. The constituent elements cool at least one heat sourceinstalled in a space A.

When the cooling systemincludes one cold plate, the cooling systemmay not include the distribution manifoldand the collection manifold.

Among the constituent elements, the CDU, the distribution manifold, the collection manifold, and the cold plateare installed in the space A. The space Ais, for example, a server room.

The space Ais provided with a rack. For example, a plurality of the heat sourcesare accommodated in the rack. Each heat sourceis typically an electronic component or electronic equipment. The electronic component is a component constituting electronic equipment, and includes, for example, a central processing unit (so-called CPU), an electrolytic capacitor, a power semiconductor module, or a printed circuit board. The electronic component operates by power supply and generates heat. The electronic equipment is a rack mounted server or a blade server. The electronic equipment may also be a projector, a personal computer, or a display.

The CDUis commercially available as a constituent element of the cooling system. In the case of circulation as the cooling system, the cooling deviceand the flow pathsandmay be excluded from the cooling system. The CDUmay be circulated on the market alone. In the present example embodiment, the CDUis accommodated, for example, in the rackwhen in use. However, the present disclosure is not limited to this, and the CDUmay be installed outside the rackwhen in use.

The CDUincludes a housing. The housingincludes an exterior body and a frame, and partitions the internal space of the CDUfrom the external space of the CDUby the exterior body. The housinghas a primary inflow port, a primary outflow port, a secondary inflow port, and a secondary outflow portin the exterior body.

A low-temperature primary refrigerant Cflows into the primary inflow portthrough the flow path. A high-temperature secondary refrigerant Cflows into the secondary inflow portfrom the collection manifold. The CDUperforms heat exchange by the heat exchanger(see) between the primary refrigerant C(low temperature) flowing into the CDUfrom the primary inflow portand the secondary refrigerant C(high temperature) flowing into the CDUfrom the secondary inflow port. As a result, in the CDU, the thermal energy of the secondary refrigerant Cmoves to the primary refrigerant C. Specifically, the temperature of the secondary refrigerant Cdecreases when flowing out of the CDUas compared with when flowing into the CDU. The CDUpumps the secondary refrigerant Chaving a low temperature from the secondary outflow porttoward the distribution manifoldby the pumpsand(see). The CDUsends the primary refrigerant Chaving a high temperature from the primary outflow portto the flow path.

The primary refrigerant Cis, for example, a fluid such as a coolant. Examples of the coolant include antifreeze liquid and pure water. A typical example of antifreeze liquid is an ethylene glycol aqueous solution or a propylene glycol aqueous solution. The secondary refrigerant Cis a fluid of the same type as or a different type from the primary refrigerant C. At least one of the primary refrigerant Cand the secondary refrigerant Cmay be a gas refrigerant.

In, the distribution manifoldhas a common flow pathand a plurality of individual flow paths. In, only two individual flow pathsare illustrated for convenience of description. Fluids can flow through the common flow pathand the individual flow paths. One end Tof the common flow pathis connected to the secondary outflow port, and is used as an inflow port for a fluid in the distribution manifold. One end Tof each individual flow pathis connected to the common flow path. The other ends Tof the individual flow pathsare used as outflow ports for the secondary refrigerant Cin the distribution manifold, and are individually connected to an inflow portof the cold plate. Therefore, the secondary refrigerant C(low temperature) flowing into the inflow port (that is, the one end T) of the distribution manifoldfirst flows in the common flow path, is divided into the individual flow paths, and then flows out from the respective outflow ports (that is, the other ends T) of the distribution manifold.

In each example embodiment, the term “connection” means “connection through which a fluid can flow” unless there is an adjective verb additionally describing “connection”.

In, each cold plateis in thermal contact with at least one heat source. The secondary refrigerant C(low temperature) flows inside each cold plate. In detail, each cold plateis arranged in direct thermal contact with the heat source. Each cold platemay be arranged in thermal contact with the heat sourcevia a thermally conductive sheet (not shown), for example. That is, the term “thermal contact” includes the meaning of “direct thermal contact” and the meaning of “indirect thermal contact”.

Each cold platehas the inflow port, an outflow port, and an internal flow pathfor the secondary refrigerant C. The internal flow pathconnects the inflow portand the outflow port. The secondary refrigerant C(low temperature) flows into the inflow portfrom the individual flow pathconnected to the inflow port. The secondary refrigerant Cflows through the internal flow pathto the outflow port. Therefore, the heat energy generated at the heat sourcemoves to the secondary refrigerant Cflowing through the internal flow pathof the cold platein thermal contact with the heat source. As a result, the heat sourceis cooled, and the temperature of the secondary refrigerant Crises. The secondary refrigerant C(high temperature) flows out of the outflow portto the individual flow pathof the collection manifold.

In, the collection manifoldincludes a plurality of the individual flow pathsand the common flow path. In, two individual flow pathsare illustrated for convenience of description. A fluid can flow through each of the individual flow pathsand the common flow path. One end Tof each individual flow pathis individually connected to the outflow portas an inflow port for the fluid in the collection manifold. The other end Tof each of the individual flow pathsis connected to the common flow path. One end Tof the common flow pathis used as an outflow port of the fluid in the collection manifold, and is connected to the secondary inflow port. Therefore, the secondary refrigerant Cflowing from the cold plateinto each inflow port (that is, the one end T) in the collection manifoldmerges at the common flow path, and flows out from one end (that is, the one end T) of the collection manifold to the secondary inflow portof the CDU. Therefore, the secondary refrigerant Ccirculates through the CDU, the distribution manifold, the cold plate, and the collection manifoldin this order.

In, the cooling deviceis installed outside the space A, for example. The cooling devicemay be installed either indoors or outdoors. The cooling deviceis, for example, a chiller or a cooling tower. The cooling deviceincludes an inflow port, an outflow port, and an internal flow pathfor the primary refrigerant C, a cooling unit, and a pump. The internal flow pathconnects the inflow portand the outflow port. Each of the cooling unitand the pumpis inserted on the internal flow path.

The primary refrigerant Cflowing into the inflow portflows into the cooling unitthrough the flow path. The cooling unitcools the primary refrigerant Cflowing into the cooling unit. The cooling system in the cooling unitmay be either an air cooling system or a water cooling system. The primary refrigerant Cflowing out of the cooling unitflows into the pumpthrough the internal flow path. The pumppumps, toward the outflow port, the primary refrigerant Cflowing into the pump. In, the pumpis positioned between the cooling unitand the outflow portin the internal flow path. However, the present disclosure is not limited to this, and the pumpmay be positioned between the outflow portand the cooling unitin the internal flow path.

Next, each part of the CDUwill be described with reference to.

Inand subsequent drawings, a Z direction, an X direction, direction intersecting each other are illustrated.

The Z direction, the X direction, and the Y direction are defined based on a state in which the CDUis installed so as to be usable (hereinafter, also referred to as a “use state”). In particular, the Z direction, the X direction, and the Y direction are an up-down direction, a front-back direction, and a left-right direction of the CDUin the use state.

One side and the other side in the Z direction are also referred to as one side Zin the Z direction and the other side Zin the Z direction. In the present example embodiment, the one side Zin the Z direction and the other side Zin the Z direction are an upward direction and a downward direction of the cooling systemin a use state.

One side and the other side in the X direction are also referred to as one side Xin the X direction and the other side Xin the X direction. In the present example embodiment, the one side Xin the X direction is a direction in which the openingsandface in the CDUin the use state. The other side Xin the X direction is a direction opposite to the one side Xin the X direction.

One side and the other side in the Y direction are also referred to as one side Yin the Y direction and the other side Yin the Y direction. In the present example embodiment, the one side Yin the Y direction is a left direction toward the openingsandin the CDUin the use state. The other side Yin the Y direction is a direction opposite to the one side Yin the Y direction.

In, the CDUfurther includes a primary flow path, a motor actuator, a secondary flow path, a heat exchanger, a sensor unit, an operation unit, and a control unitas constituent elements.

The primary flow pathincludes a flow path assembly, a three-way valve, a pipe portion, a merging pipe, and a flow path(described later) of the heat exchanger. The primary flow pathis installed in the housing. The primary flow pathis a pipe through which the primary refrigerant Cflows in the CDU.

The flow path assemblyhas a flow path that connects the primary inflow portand an inflow port Pof the three-way valve

The three-way valveincludes a valve box, a valve body, a valve rod, and the like. The valve box has the inflow port P, a first outflow port P, and a second outflow port Pas three ports to which pipes can be connected. The valve box further has a cavity. The cavity connects the three ports to each other to allow fluid to flow therethrough. The valve body is accommodated in the cavity. The valve body rotates in the cavity by the force transmitted from the outside through the valve rod. With the rotation of the valve body, an opening degree Dof the first outflow port Pand an opening degree Dof the second outflow port Pare adjusted in a state where the opening degree of the inflow port Pis maintained at a predetermined value V[%]. Specifically, the total of the opening degree Dand the opening degree Dis adjusted to be a predetermined value V.

In the present example embodiment, the opening degrees Dand Deach are ratios between the opening area of the port at an arbitrary movement amount of the valve body and the opening area when the port is fully opened. For ease of understanding, the opening degrees Dand Dare expressed in percentage. In this case, each of the predetermined values Vand Vis approximately 80 [%] or more and 120 [%] or less. The predetermined values Vand Vmay be fixed values or variable values.

For example, assuming that the predetermined values Vand Vare 100 [%], if the opening degree Dis 90 [%], the opening degree Dis 10 [%]. When the opening degree Dis 80 [%], 60 [8], 40 [%], or 20 [%], the opening degree Dis 20 [%], 40 [%], 60 [%], or 80 [%]. By adjusting the opening degrees Dand Din this manner, a part of the primary refrigerant Cflows from the three-way valvetoward the primary outflow portvia the heat exchangerin the primary flow path. On the other hand, the rest of the primary refrigerant Cflows in the primary flow pathfrom the three-way valvetoward the primary outflow portwithout passing through the heat exchanger.

The pipe portionconnects the first outflow port Pof the three-way valveand the primary inflow portof the heat exchanger.

The merging pipehas three ports and a flow path that makes the three ports continuous with each other. The three ports are a first port P, a second port P, and a third port P. The first port Pis connected to the second outflow port Pof the three-way valve. The second port Pis connected to the primary outflow portof the heat exchanger. The third port Pis connected to the primary outflow port

The motor actuatorincludes a motor and a link mechanically connected to the output shaft of the motor. The link rotates the valve rod of the three-way valveby the power from the motor. When the power supplied to the CDUis lost, the motor actuatorrotates the valve rod of the three-way valveso as to set the opening degree Dof the first outflow port Pof the three-way valveto 0 [%].

The secondary flow pathincludes a flow path assembly, a branch pipe, couplingsto, the pumpsand, a merging pipe, a pipe portion, and a flow path(described later) of the heat exchanger. The secondary flow pathis installed in the housing. The secondary flow pathis a pipe for the secondary refrigerant Cin the CDU.

The flow path assemblyconnects the secondary inflow portand the secondary inflow portof the heat exchanger.

The branch pipehas three ports and a flow path that makes the three ports continuous with each other. The three ports are a first port P, a second port P, and a third port P. The first port Pis connected to a secondary outflow portof the heat exchanger. The second port Pis connected to the coupling. The third port Pis connected to the coupling

The merging pipehas three ports and a flow path that makes the three ports continuous with each other. The three ports are a first port P, a second port P, and a third port P. The first port Pis connected to the coupling. The second port Pis connected to the coupling. The third port Pis connected to the secondary outflow port

Each of the pumpsandincludes a housing, a pump motor, a pump rotor, an inflow port, an outflow port, and the like. In each of the pumpsand, the inflow port can be connected to any of the couplingsand. In each of the pumpsand, the outflow port can be connected to any of the couplingsand. As a result, the pumpsandare connected to the secondary flow path.

In a state where at least one of the pumpsandis connected to the secondary flow path, the pump rotor rotates by the power from the pump motor in the housing. As a result, each of the pumpsandsucks the refrigerant from its own inflow port, and pressure-feeds the sucked refrigerant from the outflow port.

The heat exchangeris, for example, a plate-type heat exchanger. The heat exchangerincludes a plurality of heat transfer plates stacked in the same direction (that is, a laminate of heat transfer plates), the primary inflow port, the primary outflow port, the secondary inflow port, and the secondary outflow port

Each of the primary inflow port, the primary outflow port, the secondary inflow port, and the secondary outflow portis defined in, for example, a heat transfer plate located at one end of the laminate. In addition, the flow paththrough which the primary refrigerant Cflows between the primary inflow portand the primary outflow portis defined in the laminate. Moreover, the flow paththrough which the secondary refrigerant Cflows between the secondary inflow portand the secondary outflow portis defined in the laminate.

In the heat exchanger, the primary refrigerant Cflows into the flow pathin the laminate from the primary inflow port, and flows through the laminate toward the primary outflow port. The secondary refrigerant Cflows into the flow pathin the laminate from the secondary inflow port, and flows through the laminate toward the secondary outflow port

In the laminate of the heat transfer plates, the secondary refrigerant Cand the primary refrigerant Cflow in a physically separated state. Each heat transfer plate is made of a material having a relatively small heat transfer resistance. Therefore, in the laminate, heat exchange is performed between the primary refrigerant Cand the secondary refrigerant C. That is, the heat exchangerperforms heat exchange between the primary refrigerant Cand the secondary refrigerant C. As a result of the heat exchange, the thermal energy of the secondary refrigerant Cis transferred to the primary refrigerant C. That is, the secondary refrigerant Chas a lower temperature when flowing out of the secondary outflow portthan when flowing into the secondary inflow port

The sensor unitincludes a pressure sensor, temperature sensorsto, and flow rate sensorsand

The pressure sensor, the temperature sensorsto, and the flow rate sensorsandoutput signals correlated with the pressure, temperature, and flow rate, which are detection targets of the sensors, to the control unit.

The detection target of the pressure sensoris the pressure in the flow path assembly