Expansion valve and refrigeration system

Abstract

In an expansion valve through which a two-phase refrigerant flows, if there is a groove in the valve chamber, liquid refrigerant can easily enter, and the splashing liquid refrigerant disrupts the flow of the gaseous refrigerant, causing abnormal noise. [Solution] The indoor expansion valve 51 is an expansion valve that reduces the pressure of the refrigerant. The indoor expansion valve 51 comprises a valve body 41, a first pipe 100, and a second pipe 200. The valve body 41 has a valve chamber 43 in which a valve element 42 is housed. The first pipe 100 is connected to the valve chamber 43 along a first direction which is the axial direction of the valve element 42. The second pipe 200 is connected to the valve chamber 43 along a second direction which intersects the first direction. The thickness T of the second pipe 200 at a reference position L0, which is the end 200a on the valve chamber 43 side, is smaller than the thickness T of the second pipe 200 at a first position L1 which is a first distance away from the reference position L0 on the opposite side of the valve chamber 43 in the second direction.

Description

Technical Field

[0001] It relates to an expansion valve.

Background Art

[0002] There has conventionally been an electric valve in which a rotor and a valve shaft rotate, and a valve body seats on a valve seat member to close a valve port (Patent Document 1 (Japanese Patent Application Laid-Open No. 2024-93962)).

Summary of the Invention

Problems to be Solved by the Invention

[0003] In an expansion valve through which a two-phase refrigerant flows, if there is a groove in the valve chamber, liquid refrigerant is likely to enter, and the splashing liquid refrigerant may disrupt the flow of the high-velocity gas refrigerant, resulting in the generation of abnormal noise.

Means for Solving the Problems

[0004] The expansion valve of the first aspect is an expansion valve that reduces the pressure of a refrigerant, and includes a valve body, a first pipe, and a second pipe. The valve body has a valve chamber in which a valve element is accommodated. The first pipe is connected to the valve chamber along a first direction that is the axial direction of the valve element. The second pipe is connected to the valve chamber along a second direction that intersects the first direction. The thickness of the second pipe at a reference position that is the end on the valve chamber side is smaller than the thickness at a first position that is at a first distance from the reference position on the side opposite to the valve chamber in the second direction.

[0005]

[0006]

[0007]

[0008] In this expansion valve, by reducing the thickness of the end on the valve chamber side of the second pipe, it is possible to suppress the refrigerant from colliding with the end of the second pipe and becoming droplets, thereby suppressing the generation of noise. ​

[0008] The expansion valve in the third view is the expansion valve in the second view, in which the second pipe has the greatest wall thickness between a second position, which is a second distance greater than the first distance from the reference position on the opposite side of the valve chamber, and a third position, which is a third distance greater than the second distance from the reference position on the opposite side of the valve chamber. The distance between the inner surface of the reference position and the inner surface of the second position is smaller than the distance between the reference position and the second position in the second direction.

[0009] In this expansion valve, noise generation can be suppressed by making the distance between the inner surface of the reference position and the inner surface of the second position smaller than the distance between the reference position and the second position in the second direction.

[0010] The expansion valve in the fourth view is the expansion valve in the third view, wherein the second pipe has a wall thickness at a fourth position, which is less than the second distance away from the reference position on the opposite side of the valve chamber, that is greater than the wall thickness at the reference position and less than the wall thickness at the second position.

[0011] In this expansion valve, the wall thickness at the fourth position, which is between the reference position and the second position, is greater than the wall thickness at the reference position and smaller than the wall thickness at the second position, thereby creating a slope on the inside of the second pipe.

[0012] The The 5-point expansion valve is a 4-point expansion valve, and the 2nd pipe is located at a 2nd distance from the reference position to the side opposite the valve chamber. twist The wall thickness at the fifth position, which is a smaller fifth distance away, is the same as the wall thickness at the reference position.

[0013] In this expansion valve, a horizontal section with a thinner wall thickness and a slope can be formed inside the second pipe.

[0014] The expansion valve in the sixth viewpoint is the expansion valve in the first viewpoint, wherein the second pipe has an outer diameter at the reference position that is smaller than the outer diameter at the first position.

[0015] In this expansion valve, the outer diameter at the reference position is smaller than the outer diameter at the first position, which allows the refrigerant to flow more easily toward the inner wall of the second pipe.

[0016] The seventh aspect expansion valve is an expansion valve from either the first or sixth aspect, and its wall thickness at the reference position is 0.7 mm or more.

[0017] This expansion valve ensures strength at the end of the second pipe.

[0018] The expansion valve of the eighth perspective is an expansion valve of either the first or seventh perspective, and the valve body has a valve seat. The valve seat allows the flow area of ​​the refrigerant to be varied by the movement of the valve body. The valve body has an inclined portion. When the expansion valve is fully closed, the inclined portion is located on the first pipe side of the valve seat. When the expansion valve is in the first state, the inner wall of the second pipe is located on the extension of the inclined portion.

[0019] In this expansion valve, the inclined portion of the valve body guides the refrigerant toward the inner wall of the second pipe, thereby suppressing the refrigerant from colliding with the end of the second pipe and bouncing back.

[0020] The expansion valve in the ninth perspective is the expansion valve in the eighth perspective, and the first state is when the opening of the expansion valve is 5-40% of the opening when the fully open state is 100%.

[0021] In this expansion valve, when the valve opening is small, the refrigerant tends to become a two-phase gas-liquid system.

[0022] The expansion valve in the tenth perspective is the expansion valve in the eighth perspective, and the first state is a state in which there are no obstacles between the inclined portion and the inner wall of the second pipe on the extension of the inclined portion.

[0023] In this expansion valve, in the first state, the valve body moves away from the first pipe side, making it easier for the refrigerant to flow toward the inner wall of the second pipe.

[0024] The expansion valve according to the 11th aspect is any one of the expansion valves from the 1st aspect to the 10th aspect, and the refrigerant is a single refrigerant composed of carbon dioxide or a mixed refrigerant containing carbon dioxide.

[0025] In this expansion valve, even when a high-pressure refrigerant flows, noise can be suppressed.

[0026] The refrigeration device according to the 12th aspect includes a utilization unit and a heat source unit. The utilization unit has the expansion valve described in any one of the 1st aspect to the 11th aspect. The heat source unit is connected to the utilization unit.

[0027] In this refrigeration device, by reducing the wall thickness of the end portion on the valve chamber side of the second pipe of the expansion valve, it is possible to suppress the refrigerant flowing from the first pipe of the expansion valve into the valve chamber from colliding with the end portion of the second pipe and becoming droplets, and to suppress the generation of noise.

Brief Description of the Drawings

[0028] [Figure 1] It is a diagram showing the refrigeration cycle of an air conditioner. [Figure 2] It is a schematic diagram showing the pressure-enthalpy state of a CO2 refrigerant. [Figure 3] It is a detailed diagram showing the pressure-enthalpy state of a CO2 refrigerant (a drawing using Fundamentals: 2005 Ashrae Handbook: Si Edition). [Figure 4] It is a longitudinal sectional view of the expansion valve according to the present embodiment. [Figure 5A] It is a schematic sectional view of the expansion valve according to the present embodiment. <0000I07> [Figure 5B] It is a diagram showing an example of the cross section of the second pipe. [Figure 5C] It is a diagram showing an example of the cross section of the second pipe. [Figure 6A] It is a schematic sectional view of the expansion valve according to Modification 1A. [Figure 6B] It is a diagram showing another example of the cross section of the second pipe. [Figure 6C] It is a diagram showing another example of the cross section of the second pipe. [Figure 7] This is a schematic cross-sectional view of the expansion valve according to Modification 1B. [Figure 8] This is a schematic cross-sectional view of the expansion valve according to Modification 1C. [Figure 9] This is a schematic cross-sectional view of the expansion valve according to modified example 1D. [Figure 10] This is a schematic cross-sectional view of the expansion valve according to modified example 1E. [Figure 11] This is a schematic cross-sectional view of the expansion valve relating to Modification 1F. [Figure 12] This is a longitudinal cross-sectional view of the expansion valve according to modified example 1G. [Figure 13] This is a diagram illustrating the state of the refrigerant. [Modes for carrying out the invention]

[0029] (1) Overall configuration of the air conditioning system Figure 1 shows the refrigeration cycle of an air conditioning system 10 having a refrigeration system utilization unit employing the expansion valve of this disclosure. The air conditioning system 10 comprises an indoor unit (refrigeration system utilization unit) 50 and an outdoor unit (refrigeration system heat source unit) 20. The indoor unit 50 has an indoor expansion valve (expansion valve) 51. The outdoor unit 20 is connected to the indoor unit 50. The air conditioning system 10 uses carbon dioxide (hereinafter referred to as CO2 refrigerant) as a refrigerant.

[0030] The air conditioning system 10 is a device installed in buildings such as office buildings to cool or heat multiple spaces, and is a multi-type air conditioning system in which multiple indoor units 50 are connected to one outdoor unit 20. This air conditioning system 10 consists of an outdoor unit 20, multiple indoor units 50, and refrigerant connecting pipes 6 and 7 that connect the two units 20 and 50.

[0031] The outdoor unit 20 includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an outdoor expansion valve 24, shut-off valves 25, 26, and the like.

[0032] Each indoor unit 50 has an indoor expansion valve 51 and an indoor heat exchanger 52.

[0033] The indoor expansion valve 51 is an expansion valve that reduces the pressure of the refrigerant. The indoor expansion valve 51 is connected to the first connecting pipe 111, which is connected to the indoor heat exchanger 52. The indoor expansion valve 51 is also connected to the second connecting pipe 112, which is connected to the connection point with the refrigerant communication pipe 6.

[0034] The indoor units 50 are installed on the ceilings of each space (such as rooms) within the building and are connected to the outdoor units 20 by refrigerant connecting pipes 6 and 7.

[0035] As shown in Figure 1, the refrigeration cycle of this air conditioning system 10 is a closed circuit in which the compressor 21, four-way switching valve 22, outdoor heat exchanger 23, outdoor expansion valve 24, indoor expansion valve 51, and indoor heat exchanger 52 are connected by refrigerant piping including refrigerant connecting pipes 6 and 7.

[0036] (2) Basic operation of air conditioning system The air conditioning system 10 can perform air conditioning operation to cool or heat the space inside the building by exchanging heat between the CO2 refrigerant flowing through the indoor heat exchanger 52 of the indoor unit 50 and the indoor air.

[0037] The air conditioning unit 10 can switch between heating and cooling operation by switching the direction of refrigerant flow with the four-way switching valve 22.

[0038] During cooling operation, the outdoor heat exchanger 23 acts as a gas cooler, and the indoor heat exchanger 52 acts as an evaporator. Conversely, during heating operation, the outdoor heat exchanger 23 acts as an evaporator, and the indoor heat exchanger 52 acts as a gas cooler.

[0039] In Figure 1, point A is the suction side of the compressor 21 during heating operation, and point B is the discharge side of the compressor 21 during heating operation. Point C is the refrigerant outlet side of the indoor heat exchanger 52 during heating operation, and point D is the refrigerant inlet side of the outdoor heat exchanger 23 during heating operation.

[0040] Figure 2 is a simplified diagram showing the pressure-enthalpy state of the CO2 refrigerant, with the vertical axis representing pressure and the horizontal axis representing enthalpy. Figure 3 is a detailed diagram showing the pressure-enthalpy state of the CO2 refrigerant (a diagram using Fundamentals: 2005 Ashrae Handbook: Si Edition).

[0041] Tcp is an isotherm that passes through the critical point CP. In the region to the right of this isotherm Tcp and above the critical pressure (the pressure at the critical point CP), the CO2 refrigerant becomes supercritical, becoming a fluid that possesses both the diffusivity of a gas and the solubility of a liquid. The air conditioning system 10 operates in a refrigeration cycle that includes the supercritical state, as shown by the thick line in Figure 2. In the refrigeration cycle for heating operation, the CO2 refrigerant is compressed in the compressor 21 to a pressure exceeding the critical pressure, cooled in the indoor heat exchanger 52 to become a liquid, depressurized in the indoor expansion valve 51 and the outdoor expansion valve 24, evaporated in the outdoor heat exchanger 23, and then drawn back into the compressor 21 as a gas.

[0042] (3) Structure of the indoor expansion valve Next, the structure of the indoor expansion valve 51 will be described. Figure 4 is a longitudinal cross-sectional view of the indoor expansion valve 51. Figure 5A is a schematic cross-sectional view of the indoor expansion valve 51. Figures 5B and 5C show examples of cross-sections of the second pipe 200. The arrow F in Figure 5A indicates the direction of refrigerant flow. In this embodiment, the indoor expansion valve 51 is a motor-driven expansion valve. The indoor expansion valve 51 mainly consists of a valve body 41 and the first pipe 100 And, the second section 200 It also includes a drive mechanism (not shown).

[0043] (3-1) Valve body The valve body 41 has a valve chamber 43 in which the valve element 42 is housed. A guide member 46 is attached to the valve body 41 so as to be inserted into the valve chamber 43 from above. The valve body 42 has a valve head 42a at one end and moves up and down (first direction) by a drive mechanism (not shown). In this embodiment, the valve body 42 has a needle shape and is positioned so that its axis is oriented in the up and down direction.

[0044] The valve body 41 consists of a valve chamber 43 which is a hollow space into which the valve element 42 is inserted, and the valve chamber 43 is divided into first connection A first pipe that opens to face the valve head 42a in order to connect to the piping 111. 100 And the valve chamber 43 is the second connection A second pipe opens into the valve chamber 43 in a direction intersecting the valve body shaft in order to connect to the piping 112. 200 The valve body 41 has a valve seat 44 whose flow area for the refrigerant between it and the valve head 42a is varied by the movement of the valve body 42. In this embodiment, the valve body 41 is located below a drive mechanism (not shown).

[0045] Furthermore, the valve body 41 has a valve seat 44. The valve seat 44 is a component having an orifice hole 45 to which the valve head 42a can abut. The flow area of ​​the refrigerant is varied by the movement of the valve body 42.

[0046] The valve body 42 is inclined portion (Valve body inclined section) It has a 42b. When the opening of the indoor expansion valve 51 is in the fully closed position, the inclined portion 42b is located on the first pipe 100 side of the valve seat 44.

[0047] When the opening degree of the indoor expansion valve 51 is in the first state, the inner wall of the second pipe 200 is located on the extension of the inclined portion 42b. In other words, when the opening degree of the indoor expansion valve 51 is in the first state, there is no obstruction between the inclined portion 42b and the inner wall of the second pipe 200 on the extension of the inclined portion 42b. For example, as shown in Figure 5A, when the opening degree of the indoor expansion valve 51 is in the first state, the lower guide surface 46a of the guide member 46 is not located between the inclined portion 42b and the inner wall of the second pipe 200 on the extension of the inclined portion 42b.

[0048] When the opening degree of the indoor expansion valve 51 is in the first state, the opening degree of the indoor expansion valve 51 is 5 to 40% of the opening degree when the fully open state is considered to be 100%. In this embodiment, when the opening degree of the indoor expansion valve 51 is in the first state, it is 20% of the opening degree when the fully open state is considered to be 100%.

[0049] (3-2) Pipe 1 In this embodiment, the first pipe 100 has one end that is the first connection It is connected to piping 111, and the other end is a pipe section connected to the lower side of valve chamber 43. 100 It is connected to the valve chamber 43a along the first direction (vertical direction), which is the axial direction of the valve body 42.

[0050] (3-3) 2nd pipe In this embodiment, the second pipe 200 has one end that is the second connection The second pipe 200 is connected to the piping 112, and its other end is provided to open from the side of the valve chamber 43 toward the valve body 42. The second pipe 200 is connected to the valve chamber 43 along a second direction (left-right direction) that intersects with the first direction.

[0051] In this embodiment, the second pipe 200 is fixed by a stopper 47.

[0052] As shown in Figures 5A to 5C, in this embodiment, the second pipe 200 has an inclined portion 200b in the radial direction, from a position between the outer and inner surfaces of the end 200a of the second pipe 200 toward the direction of refrigerant outflow, such that the inner diameter of the first position L1 becomes smaller than that of the reference position L0. In other words, the second pipe 200 has an inclined portion 200b starting from the middle of the pipe's wall thickness direction.

[0053] As shown in Figure 5B, the wall thickness T (wall thickness T0) of the second pipe 200 at reference position L0, which is the end 200a on the valve chamber 43 side, is smaller than the wall thickness T (wall thickness T1) at first position L1, which is a first distance away from the reference position L0 on the opposite side of the valve chamber 43 in the second direction. The wall thickness of the second pipe 200 at reference position L0 is 0.7 mm or more.

[0054] As shown in Figure 5C, the second pipe 200 is located at a second position L2, which is a second distance greater than the first distance from the reference position L0 to the valve chamber 43 side, and from the reference position L0 to the valve chamber 43 side. and the opposite sideThe wall thickness T is greatest between the reference position L0 and the third position L3, which is a third distance greater than the second distance. In this embodiment, the wall thickness T of the second pipe 200 between the second position L2 and the third position L3 is 1.2 mm. Furthermore, the wall thickness T (wall thickness T4) of the second pipe 200 at the fourth position L4, which is a fourth distance less than the second distance L2 from the reference position L0 on the opposite side of the valve chamber 43, is greater than the wall thickness T (wall thickness T0) at the reference position L0 and smaller than the wall thickness T (wall thickness T2) at the second position L2.

[0055] In this embodiment, the outer diameter of the second pipe 200 remains constant, and the inner circumference of the second pipe 200 has an inclined portion. Therefore, the outer diameter of the second pipe 200 at the reference position L0 is the same as the outer diameter at the first position L1.

[0056] The end portion 200a of the second pipe 200, which is the reference position L0, faces the valve chamber 43 and is the part of the second pipe 200 with the largest inner diameter.

[0057] The inner diameter of the second pipe 200 decreases in the direction of refrigerant outflow, starting from the end 200a, which is the reference position L0 of the second pipe 200.

[0058] The inner diameter of the second pipe 200 is smallest at the second position L2 and the third position.

[0059] (4) Operation of the indoor expansion valve Next, the operation of the indoor expansion valve 51 will be explained.

[0060] Start the compressor 21 and other components, and the air conditioning system 10 refrigerant cycle within the road When the refrigerant begins to circulate, the liquid refrigerant that comes out of the indoor heat exchanger 52 is first connection The liquid refrigerant flows from the first pipe 100 into the valve chamber 43 through the piping 111. The liquid refrigerant expands as it passes through the flow path formed by the valve head 42a and the orifice hole 45 of the valve seat 44, and is blown out into the valve chamber 43, while also flowing in so as to collide with the inclined portion 200b on the inner circumference of the second pipe 200. The liquid refrigerant that has flowed into the valve chamber 43 then becomes a gas-liquid two-phase system, flows along the second direction, and flows out from the second pipe 200.

[0061] (5) Characteristics (5-1) The indoor expansion valve 51 according to this embodiment is an expansion valve that reduces the pressure of the refrigerant. The indoor expansion valve 51 comprises a valve body 41, a first pipe 100, and a second pipe 200. The valve body 41 has a valve chamber 43 in which a valve element 42 is housed. The first pipe 100 is connected to the valve chamber 43 along a first direction which is the axial direction of the valve element 42. The second pipe 200 is connected to the valve chamber 43 along a second direction which intersects the first direction. The thickness T of the second pipe 200 at a reference position L0, which is the end 200a on the valve chamber 43 side, is smaller than the thickness T of the second pipe 200 at a first position L1 which is a first distance away from the reference position L0 on the opposite side of the valve chamber 43 in the second direction.

[0062] Figure 13 is a diagram illustrating the state of the refrigerant. When the opening of the indoor expansion valve 510 is, for example, 20% of the fully closed state (where the fully closed state is 100%), there is a gap between the valve seat 44 and the valve body 42. Because there is a gap around the valve body 42, there is naturally also a gap in the plane of the paper in Figure 13. In Figure 13, solid arrows indicate liquid refrigerant, and dashed arrows indicate gas-saturated refrigerant. In other words, the dashed arrows indicate gas-saturated refrigerant passing through the gap between the valve body 42 and the valve seat 44.

[0063] During heating operation, liquid CO2 refrigerant flows in through the first pipe 100 of the indoor expansion valve 510. As shown in Figure 13, if the wall thickness is not reduced and is at its maximum at the end 270a of the second pipe 270 of the indoor expansion valve 510, a corner of the second pipe 270 remains, creating a stepped groove 49.

[0064] Therefore, if the wall thickness of the end 270a of the second pipe 270 is large, the liquid refrigerant will become a ripple when it passes through the indoor expansion valve 510 due to the step in the stepped groove 49. Then, the refrigerant passing through the second pipe 270 will become a gas-liquid two-phase system due to pressure recovery.

[0065] In this embodiment, the indoor expansion valve 51 is connected such that, during heating operation of the air conditioning system 10, the liquid refrigerant flowing from the indoor heat exchanger 52 enters the lower side of the indoor expansion valve 51. In the indoor expansion valve 51, the liquid refrigerant flowing into the valve chamber 43 flows toward the inclined portion 200b on the inner circumference side of the second pipe 200. As a result, the noise generated when the refrigerant flowing from the first pipe 100 into the valve chamber 43 flows from the valve chamber 43 into the second pipe 200 is reduced.

[0066] In this embodiment, since the second pipe 200 has one inclined portion (inclined surface) 200b on its inner circumference, the cost of providing the inclined portion can be reduced.

[0067] In this indoor expansion valve 51, by reducing the wall thickness of the end 200a of the second pipe 200 on the valve chamber 43 side, it is possible to suppress the refrigerant from colliding with the end 200a of the second pipe 200 and becoming droplets, thereby suppressing the generation of noise.

[0068] (5-2) In the indoor expansion valve 51 according to this embodiment, the outer diameter of the second pipe 200 is the same at the reference position L0 and at the first position L1.

[0069] This indoor expansion valve 51 can suppress noise generation without changing the outer diameter of the reference position L0 and the outer diameter of the first position L1.

[0070] (5-3) In the indoor expansion valve 51 according to this embodiment, the wall thickness T of the second pipe 200 at the fourth position L4, which is a fourth distance less than the second distance away from the reference position L0 on the opposite side from the valve chamber 43, is greater than the wall thickness T at the reference position L0 and smaller than the wall thickness T at the second position L2.

[0071] In this indoor expansion valve 51, the wall thickness T at the fourth position L4, between the reference position L0 and the second position L2, is greater than the wall thickness T at the reference position L0 and smaller than the wall thickness T at the second position L2, thereby creating a slope on the inside of the second pipe 200.

[0072] (5-4) In the indoor expansion valve 51 according to this embodiment, the wall thickness at the reference position L0 is 0.7 mm or more.

[0073] This indoor expansion valve 51 ensures the strength at the end 200a of the second pipe 200.

[0074] (5-5) In the indoor expansion valve 51 according to this embodiment, the valve body 41 has a valve seat 44. The flow area of ​​the refrigerant is varied by the movement of the valve element 42 of the valve seat 44. The valve element 42 has an inclined portion 42b. When the indoor expansion valve 51 is fully closed, the inclined portion 42b is located on the first pipe 100 side of the valve seat 44. When the indoor expansion valve 51 is in the first state, the inner wall of the second pipe 200 is located on the extension of the inclined portion 42a.

[0075] In this indoor expansion valve 51, the inclined portion 42b of the valve body 42 guides the refrigerant toward the inner wall of the second pipe 200, thereby suppressing the refrigerant from colliding with and bouncing off the end 200a of the second pipe 200.

[0076] (5-6) In the indoor expansion valve 51 according to this embodiment, the first state is when the opening degree of the indoor expansion valve 51 is 20% of the opening degree, with the fully open state being 100%.

[0077] In this indoor expansion valve 51, when the opening degree of the indoor expansion valve 51 is small, the refrigerant tends to become a gas-liquid two-phase system.

[0078] (5-7) In the indoor expansion valve 51 according to this embodiment, the first state is a state in which there are no obstacles between the inclined portion 42b and the inner wall of the second pipe 200 on the extension of the inclined portion 42b.

[0079] In this indoor expansion valve 51, in the first state, the valve body 42 moves away from the first pipe 100 side, making it easier for the refrigerant to flow toward the inner wall of the second pipe 200.

[0080] (5-8) In the indoor expansion valve 51 according to this embodiment, the refrigerant is a single refrigerant consisting of carbon dioxide. This indoor expansion valve 51 can suppress noise even when high-pressure refrigerant such as CO2 refrigerant is flowing through it.

[0081] (5-9) The air conditioning system 10 according to this embodiment comprises an indoor unit 50 and an outdoor unit 20. The indoor unit 50 has an indoor expansion valve 51. The outdoor unit 20 is connected to the indoor unit 50.

[0082] In this air conditioning system 10, by reducing the wall thickness of the end 200a of the second pipe 200 of the indoor expansion valve 51 on the valve chamber 43 side, it is possible to suppress the refrigerant flowing from the first pipe 100 of the indoor expansion valve 51 into the valve chamber 43 from colliding with the end 200a of the second pipe 200 and becoming droplets, thereby suppressing the generation of noise.

[0083] (6) Variant (6-1) Variation 1A In this embodiment, the second pipe 200 is described as having an inclined portion 200b starting from the middle of the pipe's wall thickness direction, but it is not limited to this. The second pipe may also have an inclined portion starting from the middle of the pipe's axial direction. In modified example 1A, the second pipe 210 has a portion on its inner circumference with a smaller wall thickness T along the second direction (left-right direction) and an inclined portion 210b.

[0084] Figure 6A is a schematic cross-sectional view of the indoor expansion valve 51a of Modified Example 1A. Figures 6B and 6C show examples of cross-sections of the second pipe 210 of the indoor expansion valve 51a of Modified Example 1A. The arrow F in Figure 6A indicates the direction of refrigerant flow.

[0085] As shown in Figure 6B, in the modified example 1A of the indoor expansion valve 51a, the second pipe 210 has the greatest wall thickness T (wall thickness T2, T3) between the second position L2, which is a second distance greater than the first distance from the reference position L0 on the opposite side of the valve chamber 43, and the third position L3, which is a third distance greater than the second distance from the reference position L0 on the opposite side of the valve chamber 43. Also, the distance A between the inner surface of the reference position L0 and the inner surface of the second position L2 is smaller than the distance B between the reference position L0 and the second position L2 in the second direction. Furthermore, for example, let's assume that the distance B between the reference position L0 and the second position L2 in the second direction is constant. Also, let's assume that the distance between the reference position L0 and the position with wall thickness T0 that is furthest from the valve chamber 43 in the second direction is constant. In this case, if the distance A between the inner surface of the reference position L0 and the inner surface of the second position L2 is further reduced, the inclination angle will decrease.

[0086] Furthermore, as shown in Figure 6C, in the modified example 1A of the indoor expansion valve 51a, the wall thickness T (wall thickness T5) of the second pipe 210 at the fifth position L5, which is a fifth distance away from the reference position L0 and on the opposite side of the valve chamber 43 by a second smaller distance, is the same as the wall thickness T (wall thickness T0) at the reference position L0. The second pipe 210 has the same inner diameter at the reference position L0 and the fifth position. Also, the inner diameters at the second position L2 and the third position L3 are the same. Furthermore, it has an inclined section such that the inner diameters at the second position L2 and the third position L3 are smaller than the inner diameters at the reference position L0 and the fifth position L5.

[0087] In the indoor expansion valve 51a of Modified Example 1A, noise generation can be suppressed by making the distance A between the inner surface of the reference position L0 and the inner surface of the second position L2 smaller than the distance B between the reference position L0 and the second position L2 in the second direction. In addition, in Modified Example 1A, horizontal sections with a small wall thickness T and inclines can be formed on the inside of the second pipe 210.

[0088] (6-2) Variation 1B The second pipe of the indoor expansion valve may have a perpendicular plane on its inner circumference that intersects the pipe axis direction at a position away from the valve chamber side of the second pipe, on the opposite side from the valve chamber.

[0089] Figure 7 is a schematic cross-sectional view of the indoor expansion valve 51b of Modification 1B. The arrow F in Figure 7 indicates the direction of refrigerant flow. As shown in Figure 7, in Modification 1B, the second pipe 220 has a horizontal portion with a small wall thickness along the second direction (left-right direction) and a vertical portion along the first direction (up-down direction) on the inner circumference side of the second pipe 220.

[0090] (6-3) Modification 1C The second pipe of the indoor expansion valve may have two or more inclined sections on its inner circumference and a horizontal section located between the inclined sections.

[0091] Figure 8 is a schematic cross-sectional view of the indoor expansion valve 51c of modified example 1C. The arrow F in Figure 8 indicates the direction of refrigerant flow. As shown in Figure 8, in modified example 1C, the second pipe 230 has two inclined sections 230b and 230c on the inner circumference side of the second pipe 230, and a horizontal section with a small wall thickness along the second direction (left-right direction) between the two inclined sections 230b and 230c. The inner diameter of the inclined section 230b on the end 230a side is larger than the inner diameter of the horizontal section with a small wall thickness T, and the inner diameter of the horizontal section with a small wall thickness T is larger than the inner diameter of the inclined section 230c located on the opposite side from the valve chamber 43.

[0092] (6-4) Modification 1D The second pipe of the indoor expansion valve may have an inclined section only in the upper two-thirds of the radial cross-section of the second pipe.

[0093] Figure 9 is a schematic cross-sectional view of the indoor expansion valve 51d of modified example 1D. The arrow F in Figure 9 indicates the direction of refrigerant flow. As shown in Figure 9, in modified example 1D, the second pipe 240 has an inclined portion 240b on the inner circumference side of the side (upper side) fixed by the stopper 47, such that the inner diameter decreases from the end 240a toward the direction of refrigerant outflow.

[0094] (6-5) Modification 1E If there is a step between the stopper 47 and the second pipe of the indoor expansion valve, the shape of the valve chamber side of the second pipe may be made L-shaped to fill the step.

[0095] Figure 10 is a schematic cross-sectional view of the indoor expansion valve 51e of Modification 1E. The arrow F in Figure 10 indicates the direction of refrigerant flow. As shown in Figure 10, in Modification 1E, the second pipe 250 has an L-shaped end 250a on the outer circumference side of the side (upper side) that is fixed by the stopper 47. This prevents a step from occurring between the stopper 47 and the second pipe 250.

[0096] (6-6) Modification 1F If a step is created between the stopper 47 and the second pipe, the outer diameter side of the second pipe of the indoor expansion valve on the valve chamber side may be made inclined around its entire circumference to fill the step.

[0097] Figure 11 is a schematic cross-sectional view of the indoor expansion valve 51f of Modified Example 1F. The arrow F in Figure 11 indicates the direction of refrigerant flow. As shown in Figure 11, in Modified Example 1F, the second pipe 260 has an inclined portion 260b on its outer surface such that the outer diameter increases in the direction of refrigerant outflow from the end 260a. In Modified Example 1F, the outer diameter of the second pipe 260 at reference position L0 of the end 260a is smaller than the outer diameter at a first position L1 which is a first distance away from the reference position L0 on the opposite side of the valve chamber 43.

[0098] In the modified example 1F, the indoor expansion valve 51f has a smaller outer diameter at the reference position L0 than at the first position L1, which allows the refrigerant to flow more easily toward the inner wall of the second pipe 200.

[0099] (6-7) Modification 1G In this embodiment, the indoor expansion valve 51 has a stopper 47, but the indoor expansion valve does not need to have a stopper.

[0100] Figure 12 is a longitudinal cross-sectional view of the chamber expansion valve 51g of modified example 1G. As shown in Figure 12, the chamber expansion valve 51g according to modified example 1G comprises a valve body 41, a first pipe 100, a second pipe 200, and a drive mechanism (not shown). The valve body 41 also has a valve element 42, a valve chamber 43, a valve seat 44, an orifice hole 45, and a guide member 46. The first pipe 100 is joined to the valve chamber 43 of the valve body 41 along a first direction (vertical direction). The second pipe 200 is joined to the right side of the valve chamber 43 of the valve body 41 in Figure 12 along a second direction (horizontal direction).

[0101] In the modified example 1G, the indoor expansion valve 51g can suppress noise generation even without a stopper.

[0102] (6-8) Modification 1H In this embodiment, the case where the refrigerant is a single refrigerant consisting of carbon dioxide has been described, but a mixed refrigerant containing carbon dioxide may also be used. Furthermore, the refrigerant is not limited to a single refrigerant consisting of carbon dioxide or a mixed refrigerant containing carbon dioxide.

[0103] (6-9) Modification 1I The expansion valve of this disclosure is applicable to an outdoor expansion valve of a heat source unit of a refrigeration system.

[0104] (6-10) While embodiments of this disclosure have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of this disclosure as described in the claims. [Explanation of Symbols]

[0105] 6, 7 Refrigerant connecting piping 10. Air conditioning system (refrigeration system) 20 Outdoor unit (heat source unit) 41 Valve body 42 Valve body 42a Valve head 42b Slope (Valve body inclined section) 43 valve chambers 44 valve seats 45 Orifice holes 46 Guide member 46a Guide bottom surface 47 Stopper 49 Step groove 50 Indoor Units (Units for Use) 51, 51a, 51b, 51c, 51d, 51e, 51f, 510 Indoor expansion valve (expansion valve) 100 1st tube 111 First connecting pipe 112 Second connecting pipe 200, 210, 220, 230, 240, 250, 260, 270 2nd pipe 200a, 210a, 220a, 230a, 240a, 250a, 260a, 270a End 200b, 210b, 230b, 230c, 240b, 260b Slope A, B distance L0 reference position L1 1st position L2 2nd position L3 3rd position L4 4th position L5 5th position T Thickness [Prior art documents] [Patent Documents]

[0106] [Patent Document 1] Japanese Patent Publication No. 2024-93962

Claims

1. An expansion valve for reducing the pressure of a refrigerant, A valve body (41) having a valve chamber (43) in which a valve element (42) is housed, A first pipe (100) connected to the valve chamber along the first direction which is the axial direction of the valve body, A second pipe (200, 210, 220, 230, 240, 250, 260) connected to the valve chamber along a second direction intersecting the first direction, Equipped with, The aforementioned second tube is, The wall thickness (T) at the reference position (L0), which is the end (200a) on the valve chamber side, is smaller than the wall thickness at the first position (L1), which is a first distance away from the reference position on the opposite side from the valve chamber in the second direction. Expansion valves (51, 51a, 51b, 51c, 51d, 51e, 51f).

2. The aforementioned second tube is, The outer diameter at the reference position and the outer diameter at the first position are the same. The expansion valve according to claim 1.

3. The aforementioned second tube is, The wall thickness is greatest between a second position (L2), which is located at a second distance greater than the first distance from the reference position on the opposite side of the valve chamber, and a third position (L3), which is located at a third distance greater than the second distance from the reference position on the opposite side of the valve chamber. The distance (A) between the inner surface of the reference position and the inner surface of the second position is smaller than the distance (B) between the reference position and the second position in the second direction. The expansion valve according to claim 2.

4. The aforementioned second tube is, The wall thickness at the fourth position (L4), which is located at a fourth distance less than the second distance from the reference position on the opposite side of the valve chamber, is greater than the wall thickness at the reference position and less than the wall thickness at the second position. The expansion valve according to claim 3.

5. The aforementioned second tube is, The thickness at the fifth position (L5), which is located at a fifth distance (L5) that is also smaller than the second distance from the reference position and on the opposite side of the valve chamber, is the same as the thickness at the reference position. The expansion valve according to claim 4.

6. The aforementioned second tube is, The outer diameter at the reference position is smaller than the outer diameter at the first position. The expansion valve according to claim 1.

7. The wall thickness at the aforementioned reference position is 0.7 mm or more. An expansion valve according to any one of claims 1 to 6.

8. The valve body has a valve seat (44) in which the flow area of ​​the refrigerant is varied by the movement of the valve body, The valve body is, When the expansion valve is fully closed, it has an inclined portion (42b) located on the first pipe side of the valve seat, When the opening degree of the expansion valve is in the first state, the inner wall of the second pipe is located on the extension of the inclined portion. An expansion valve according to any one of claims 1 to 6.

9. The first state is when the opening of the expansion valve is 5 to 40% of the opening when the fully open state is defined as 100%. The expansion valve according to claim 8.

10. The first state is a state in which, along the extension of the inclined portion, there is no obstacle between the inclined portion and the inner wall of the second pipe. The expansion valve according to claim 8.

11. The refrigerant is a single refrigerant consisting of carbon dioxide or a mixed refrigerant containing carbon dioxide. An expansion valve according to any one of claims 1 to 6.

12. A user unit (50) having an expansion valve (51, 51a, 51b, 51c, 51d, 51e, 51f) according to any one of claims 1 to 6, A heat source unit (20) connected to the aforementioned utilization unit, A refrigeration device (10) equipped with the following features.

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