Shell-And-Plate Heat Exchanger and Refrigeration Apparatus

This is a continuation of International Application No. PCT/JP2024/008359 filed on Mar. 5, 2024, which claims priority under 35 U.S.C. § 119(a) to Patent Application No. 2023-053919, filed in Japan on Mar. 29, 2023, all of which are hereby expressly incorporated by reference into the present application.

The present disclosure relates to a shell-and-plate heat exchanger and a refrigeration apparatus.

Japanese Unexamined Patent Publication No. 2018-204886 discloses a refrigerant heat exchanger including a hollow container and a plate polymer housed in the internal space of the hollow container. In the refrigerant heat exchanger of Japanese Unexamined Patent Publication No. 2018-204886, a refrigerant liquid introduced through a refrigerant pipe into the internal space of the hollow container exchanges heat with a refrigerant liquid flowing through a penetration channel of the plate polymer.

A first aspect of the present disclosure is directed to a shell-and-plate heat exchanger, including: a shell having an internal space; and a plate stack housed in the internal space and including a plurality of heat transfer plates stacked and joined together, the shell-and-plate heat exchanger causing heat exchange between a refrigerant that has flowed into the internal space of the shell and a heating medium that has flowed into a heating medium channel of the plate stack, the shell including: a cylindrical body having openings on both axial ends; a first closing member configured to close the opening on one end of the cylindrical body; and a second closing member configured to close the opening on the other end of the cylindrical body, at least one of the first closing member or the second closing member being formed into a curved shape protruding outward in an axial direction of the cylindrical body, part of the plate stack being arranged in the at least one of the first closing member or the second closing member formed into the curved shape.

As illustrated in, a shell-and-plate heat exchanger () (will be hereinafter “referred to as a heat exchanger”) is provided in a refrigeration apparatus (). The refrigeration apparatus () includes a refrigerant circuit () filled with a refrigerant. The refrigerant circuit () includes a compressor (), a radiator (), a decompression mechanism (), and the heat exchanger () serving as an evaporator. The decompression mechanism () is, for example, an expansion valve. The refrigerant circuit () performs a vapor compression refrigeration cycle.

The refrigeration apparatus () is an air conditioner. The air conditioner may be any of a cooling-only apparatus, a heating-only apparatus, or an air conditioner switchable between cooling and heating. In this case, the air conditioner has a switching mechanism (e.g., a four-way switching valve) configured to switch the direction of circulation of the refrigerant. The refrigeration apparatus () may be a water heater, a chiller unit, or a cooling apparatus configured to cool air in an internal space. The cooling apparatus cools the air in an internal space of a refrigerator, a freezer, a container, or the like.

As illustrated in, the heat exchanger () includes a shell () and a plate stack (). The plate stack () is housed in an internal space () of the shell ().

A liquid refrigerant flows into the internal space () of the shell (). The liquid refrigerant exchanges heat with a heating medium flowing in the plate stack (). As can be seen, the heat exchanger () allows the refrigerant that has flowed into the internal space () of the shell () to evaporate, and thus, functions as an evaporator. Examples of the heating medium used include water and brine.

The shell () includes a cylindrical body (), a first closing member (), and a second closing member (). The cylindrical body () is a circular cylindrical member extending in a horizontal direction and having openings on both axial ends.

The first closing member () closes an opening on one end (the left end in) of the cylindrical body (). The first closing member () is attached to the cylindrical body () by welding. The first closing member () is formed into a curved shape protruding outward in the axial direction of the cylindrical body ().

The second closing member () closes an opening on the other end (the right end in) of the cylindrical body (). The second closing member () is attached to the cylindrical body () by welding. The second closing member () is formed into a curved shape protruding outward in the axial direction of the cylindrical body ().

The shell () has the internal space () defined by the cylindrical body (), the first closing member (), and the second closing member (). The internal space () stores therein the liquid refrigerant. The plate stack () is housed in the internal space (). The cylindrical body () has an axial length that is shorter than the length of the plate stack () in a stacking direction.

Thus, a left end portion of the plate stack () beyond the left end portion of the cylindrical body () is arranged in the first closing member (). A right end portion of the plate stack () beyond the right end portion of the cylindrical body () is arranged in the second closing member ().

As can be seen, the first closing member () and the second closing member () formed into a curved shape can reduce the deformation caused by the pressure of the refrigerant that has flowed into the internal space () of the shell () and reduce the weight of the shell () as a whole. Arranging part of the plate stack () in the first closing member () and the second closing member () formed into the curved shape can reduce the size of the shell () as a whole.

The cylindrical body () is provided with a refrigerant inlet () and a refrigerant outlet (). The refrigerant inlet () is formed at the bottom of the cylindrical body (). The refrigerant is introduced into the internal space () through the refrigerant inlet ().

The refrigerant outlet () is formed at the top of the cylindrical body (). The refrigerant evaporated in the internal space () is emitted out of the shell () through the refrigerant outlet (). The refrigerant inlet () and the refrigerant outlet () are connected to the refrigerant circuit ().

The first closing member () is provided with a heating medium inlet () and a heating medium outlet (). The heating medium inlet () and the heating medium outlet () are tubular members.

The heating medium inlet () penetrates the first closing member (). The heating medium inlet () is connected to a heating medium introduction path () of the plate stack (). The heating medium inlet () supplies the heating medium to the plate stack (). The refrigerant that has flowed into the internal space () of the shell () exchanges heat with the heating medium that has flowed into heating medium channels (), which will be described later, of the plate stack ().

The heating medium outlet () penetrates the first closing member () above the heating medium inlet (). The heating medium outlet () is connected to a heating medium emission path () of the plate stack (). The heating medium outlet () emits the heating medium out of the plate stack ().

The plate stack () includes a plurality of heat transfer plates () stacked and joined together. The plate stack () is housed in the internal space () of the shell () in a posture in which the stacking direction of the heat transfer plates () is the lateral direction.

As illustrated in, the heat transfer plates () include first plates () and second plates (). The first plates () and the second plates () are alternately stacked to form the plate stack (). In the following description, for each of the first plates () and the second plates (), a surface on the left side inwill be referred to as a “front surface,” and a surface on the right side inwill be referred to as a “back surface.”

Each of the first plates () has an inlet protrusion () and an outlet protrusion (). The inlet protrusion () and the outlet protrusion () are portions of the first plate () bulged toward the front surface.

The inlet protrusion () is formed in a lower portion of the first plate (). A first inlet hole () is formed in a center portion of the inlet protrusion (). The first inlet hole () is a circular hole penetrating the first plate () in a thickness direction.

The outlet protrusion () is formed in an upper portion of the first plate (). A first outlet hole () is formed in a center portion of the outlet protrusion (). The first outlet hole () is a circular hole penetrating the first plate () in the thickness direction.

Each of the second plates () has an inlet recess () and an outlet recess (). The inlet recess () and the outlet recess () are portions of the second plate () bulged toward the back surface.

The inlet recess () is formed in a lower portion of the second plate (). A second inlet hole () is formed in a center portion of the inlet recess (). The second inlet hole () is a circular hole penetrating the second plate () in the thickness direction. The inlet recess () is positioned to face the inlet protrusion () of the first plate (). The second inlet hole () is positioned to face the first inlet hole () of the first plate ().

The outlet recess () is formed in an upper portion of the second plate (). A second outlet hole () is formed in a center portion of the outlet recess (). The second outlet hole () is a circular hole penetrating the second plate () in the thickness direction. The outlet recess () is positioned to face the outlet protrusion () of the first plate (). The second outlet hole () is positioned to face the first outlet hole () of the first plate ().

In the plate stack (), each first plate () and an adjacent one of the second plates () on the back side of the first plate () are welded together at their peripheral portions along the entire perimeter. These plates may be brazed together.

In the plate stack (), the first inlet hole () of each first plate () overlaps the second inlet hole () of an adjacent one of the second plates () on the front side of the first plate (). The rims of the overlapping first inlet hole () and second inlet hole () are welded together along the entire perimeter. These rims may be brazed together. The first inlet hole () and the second inlet hole () communicate with the heating medium channels (), which will be described later, to introduce the heating medium into the heating medium channels ().

In the plate stack (), the first outlet hole () of each first plate () overlaps the second outlet hole () of an adjacent one of the second plates () on the front side of the first plate (). The rims of the overlapping first outlet hole () and second outlet hole () are welded together along the entire perimeter. These rims may be brazed together. The first outlet hole () and the second outlet hole () communicate with the heating medium channels (), which will be described later, to emit the heating medium out of the heating medium channels ().

In the plate stack (), the inlet protrusions () and first inlet holes () of the first plates () and the inlet recesses () and second inlet holes () of the second plates () form the heating medium introduction path ().

In the plate stack (), the outlet protrusions () and first outlet holes () of the first plates () and the outlet recesses () and second outlet holes () of the second plates () form the heating medium emission path ().

The heating medium introduction path () is a passage extending in the stacking direction of the heat transfer plates () in the plate stack (). The heating medium introduction path () is a passage blocked from the internal space () of the shell (), and allows all the heating medium channels () to communicate with the heating medium inlet ().

The heating medium emission path () is a passage extending in the stacking direction of the heat transfer plates () in the plate stack (). The heating medium emission path () is a passage blocked from the internal space () of the shell (), and allows all the heating medium channels () to communicate with the heating medium outlet ().

The plate stack () includes a refrigerant channel () and a heating medium channel (). The refrigerant channel () and the heating medium channel () are formed with a heat transfer plate () interposed therebetween, and include a plurality of refrigerant channels () and a plurality of heating medium channels (). The heat transfer plate () separates the refrigerant channel () and the heating medium channel () from each other. Each of the first plate () and the second plate () includes repetition of long and narrow ridges and grooves.

Each first plate () includes first front-side protrusions () and first back-side protrusions () alternately arranged. The first front-side protrusions () bulge toward the front side of the first plate (). The first back-side protrusions () bulge toward the back side of the first plate ().

Each second plate () includes second front-side protrusions () and second back-side protrusions () alternately arranged. The second front-side protrusions () bulge toward the front side of the second plate (). The second back-side protrusions () bulge toward the back side of the second plate ().

Each of the refrigerant channels () is a channel sandwiched between the front surface of the first plate () and the back surface of the second plate (). The refrigerant channel () is a channel that communicates with the internal space () of the shell () and allows the refrigerant to flow therethrough.

Specifically, each refrigerant channel () includes channels formed between the front surfaces of the first back-side protrusions () and the back surfaces of the second front-side protrusions (), and spaces formed between the first front-side protrusions () and the second back-side protrusions ().

Each of the heating medium channels () is a channel sandwiched between the back surface of the first plate () and the front surface of the second plate (). The heating medium channel () is a channel blocked from the internal space () of the shell () and allows the heating medium to flow therethrough.

Specifically, each heating medium channel () includes channels formed between the back surfaces of the first front-side protrusions () and the front surfaces of the second back-side protrusions (), and spaces formed between the first back-side protrusions () and the second front-side protrusions ().

Flows of the heating medium and the refrigerant in the heat exchanger () will be described. The flow of the heating medium is shown by the arrows in.

As illustrated in, the heating medium flows from the heating medium inlet () into the heating medium introduction path (). The heating medium flowing through the heating medium introduction path () flows from the first inlet holes () and the second inlet holes () toward the first outlet holes () and the second outlet holes () through the heating medium channels ().

Specifically, the heating medium flowing through the heating medium introduction path () enters the heating medium channel (). The heating medium flows along the heating medium channel (), passes through the space formed between the first back-side protrusion () and the second front-side protrusion (), and enters an adjacent heating medium channel () above the heating medium channel (). In this manner, the heating medium flows upward while flowing from one end to the other of the heat transfer plate ().

Next, the flow of the refrigerant will be described below. The refrigerant that has passed through the decompression mechanism () in the refrigerant circuit () flows toward the heat exchanger (). The liquid refrigerant flows into the internal space () of the shell () through the refrigerant inlet (). The liquid refrigerant stored in the internal space () reaches close to the upper end of the plate stack (). The plate stack () is immersed in the liquid refrigerant. The refrigerant stored in the internal space () has a relatively low pressure. The low-pressure refrigerant exchanges heat with the heating medium flowing through the heating medium channels ().

Specifically, the refrigerant channel () and the heating medium channel () are adjacent to each other with the heat transfer plate () interposed therebetween. Thus, the liquid refrigerant absorbs heat from the heating medium flowing through the heating medium channel () and evaporates. The evaporated refrigerant moves from the refrigerant channel () further upward from the plate stack (). The evaporated refrigerant flows out through the refrigerant outlet () into the refrigerant circuit.

According to a feature of this embodiment, at least one of the first closing member () or the second closing member () is formed into a curved shape, which makes it possible to reduce deformation caused by the pressure of the refrigerant that has flowed into the internal space () of the shell () and reduce the weight of the shell () as a whole. Arranging part of the plate stack () in the at least one of the first closing member () or the second closing member () formed into the curved shape can reduce the size of the shell () as a whole.

According to a feature of this embodiment, the cylindrical body () has an axial length shorter than the length of the plate stack () in the stacking direction, which makes it possible to reduce the size of the shell () as a whole.

According to a feature of this embodiment, both of the first closing member () and the second closing member () are formed into a curved shape, which makes it possible to reduce deformation caused by the pressure of the refrigerant that has flowed into the internal space () of the shell () and reduce the weight of the shell () as a whole.

According to a feature of this embodiment, the first closing member () and the second closing member () are attached to the cylindrical body () by welding, which makes it possible to increase the strength of the shell ().