Thermodynamic heating device
The thermodynamic heating device optimizes refrigerant management and heat exchange through a novel passage design, reducing costs and environmental footprint by minimizing refrigerant quantity and pressure loss, thus enhancing efficiency and robustness.
Patent Information
- Application Number
- FR2023005525
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-06-02
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2043-06-02
AI Technical Summary
Existing thermodynamic heating devices face challenges in reducing manufacturing and operating costs while enhancing robustness and environmental friendliness, with a need for improved refrigerant management and heat exchange efficiency.
The thermodynamic heating device features a refrigerant passage with a cross-section area less than 35 mm², a support length greater than 5 mm, and a ratio of area to support length less than 2 mm, utilizing a tube with a constant thickness and specific geometric configurations to optimize refrigerant quantity and heat exchange without significant pressure loss.
This design achieves reduced refrigerant mass, lower pressure drop, and enhanced heat exchange efficiency, while minimizing manufacturing and operating costs and environmental impact.
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Abstract
Description
Title of the invention: Thermodynamic heating device Disclosure domain
[0001] This disclosure relates to a thermodynamic heating device comprising a tank and a heat pump configured to heat a fluid in the tank. This disclosure relates more specifically to a thermodynamic water heater. State of the art
[0002] A thermodynamic heating device comprising is known from document FR 3 077 622 Al:
[0003] a tank, said tank having an internal volume, an inlet orifice, an outlet orifice and an external tank surface, the internal volume is configured to contain a fluid to be heated intended to enter the internal volume through the inlet orifice and exit the internal volume through the outlet orifice, the external tank surface extends in a longitudinal direction, and
[0004] a heat pump (configured to heat the fluid to be heated in the internal volume), the heat pump has a refrigeration circuit in which a refrigerant is intended to circulate, the heat pump includes a condenser, the condenser has a tube, the tube is wound around the outer surface of the tank, said tube has an inner tube surface and an outer tube surface, the inner tube surface and the outer tube surface delimit between them a tube wall (of substantially constant thickness), the inner tube surface delimits a single passage containing the refrigerant, the outer tube surface has a flat outer portion in contact with the outer surface of the tank (the tube is configured to be in heat exchange with the cylindrical outer surface of the tank).
[0005] Such a thermodynamic heating device provides satisfactory results. However, the present disclosure aims to reduce as much as possible the manufacturing cost, the operating cost and / or to further increase the robustness and environmental friendliness compared to existing thermodynamic heating devices. Statement of Disclosure
[0006] To achieve at least some of the aforementioned objectives, in accordance with the disclosure, the passage has a (substantially constant) cross-section having the following characteristics:
[0007] an area less than 35 square millimeters,
[0008] the outer flat portion extending along the longitudinal direction over a support length greater than 5 millimeters, and
[0009] a ratio between the area and the support length of less than 2 millimeters.
[0010] Thus, the thermodynamic heating device allows a reduced mass of refrigerant and good energy efficiency, namely in particular a reduced pressure drop and good heat exchange between the refrigerant and the fluid to be heated via the tube.
[0011] According to a supplementary feature in accordance with this disclosure, Faire is preferably less than 25 square millimeters, more preferably less than 20 square millimeters.
[0012] Thus, either the quantity of refrigerant can be reduced, or the contact length of the outer tube surface against the outer tank surface can be increased, without significantly increasing the pressure losses due to friction against the inner tube surface. In other words, the quantity of refrigerant can be reduced or the heat exchange between the refrigerant and the fluid to be heated can be further increased.
[0013] According to another feature according to the invention, the support length is preferably greater than 6 millimeters, more preferably greater than 7 millimeters.
[0014] Thus, the heat exchange between the refrigerant and the fluid to be heated can be further increased, without significantly increasing the pressure losses due to friction against the inner surface of the tube, or the quantity of refrigerant.
[0015] According to another feature in accordance with this disclosure, preferably the outer surface of the tube has in cross-section an outer circular portion, the outer circular portion is opposite the outer flat portion and connects to the outer flat portion.
[0016] Thus, the wall thickness can be relatively small while avoiding substantial deformation of the tube under the pressure of the refrigerant fluid.
[0017] According to a complementary feature, the outer portion of the circle preferably represents less than 1 / 4 of a circle.
[0018] Thus, the ratio between the area and the support length can be reduced and therefore the pressure losses of the refrigerant against the inner surface can be reduced.
[0019] According to another feature in accordance with the disclosure, in which the inner surface of the tube has an inner flat portion separated from the outer flat portion by the tube wall, the inner circular portion is opposite the inner flat portion and connects directly to the inner flat portion.
[0020] According to an alternative feature in accordance with this disclosure, preferably the outer flat portion forms a first outer flat portion, the outer surface of the tube has a second outer flat portion, the second The outer flat portion is opposite the first outer flat portion, parallel to the first outer flat portion and connects to the first outer flat portion.
[0021] Thus, the passage has a substantially constant width between the first outer flat portion and the second outer flat portion, which makes it possible to increase the heat exchange with the outer surface of the tank with constant support length and area.
[0022] In various embodiments of the device according to the disclosure, one and / or the other of the following provisions may also be used:
[0023] - the refrigeration circuit contains less than 160 grams of refrigerant;
[0024] the refrigerant has a global warming potential (GWP) of less than 50;
[0025] the refrigerant is propane;
[0026] the tube wall has a thickness between 0.8 millimeters and 2 millimeters, preferably between 1.1 millimeters and 1.6 millimeters;
[0027] the ratio between the area and the product of the support length and the thickness is preferably less than or equal to 1.5, more preferably less than 1.4;
[0028] the tube is made of aluminium or aluminium alloy;
[0029] the tube is extruded;
[0030] the outer surface of the tank is cylindrical with a circular cross-section;
[0031] the internal volume of the tank is between 80 litres and 300 litres;
[0032] the device is a storage water heater. Brief description of the figures
[0033] Other features and advantages of this disclosure will become apparent in the following detailed description, with reference to the accompanying drawings in which:
[0034] [Fig. 1] schematically represents a thermodynamic heating device,
[0035] [Fig. 2] represents in enlarged cross-section the area marked II at the [Fig. 1], according to a first embodiment,
[0036] [Fig.3] represents in cross-section at enlarged scale the area marked II at the [Fig.1], according to a second embodiment. Detailed description of the disclosure
[0037] The figures illustrate a thermodynamic heating device 1. In the illustrated embodiments, the thermodynamic heating device is a storage water heater. Alternatively, the thermodynamic heating device could, in particular, be a central heating system for heating a dwelling.
[0038] The thermodynamic heating device 1 essentially comprises a tank 2 and a heat pump 10.
[0039] The tank 2 has an internal volume 4, an inlet orifice 6 and an outlet orifice 8. A fluid to be heated, in the illustrated embodiment of water, enters the internal volume 4 through the inlet orifice 6 and exits through the outlet orifice 8. The tank 2 has an external surface 3 which is cylindrical, of circular cross-section, and extends along a longitudinal direction X. The tank 2 also comprises a first dome 5 and a second dome 7 opposite each other along the longitudinal direction X, and between which the external surface 3 extends. The inlet orifice 6 and the outlet orifice 8 are located substantially at opposite ends of the tank along the longitudinal direction X. The inlet orifice 6 is located in the external surface 3 near the first dome 5, and the outlet orifice 8 is located in the external surface 3 near the second dome 7.The longitudinal direction X is generally vertical, with the first dome 5 located at the bottom and the second dome 7 at the top. The longitudinal direction X can also be horizontal, rarely oblique. The external surface of the tank 3 has, transversely to the longitudinal direction X, a diameter preferably between 40 centimeters and 60 centimeters, in particular 45 centimeters or 50 centimeters. The internal volume of the tank 2 is preferably between 80 liters and 300 liters.
[0040] The heat pump 10 is configured to heat the fluid contained in the internal volume 4 of the tank 2. The heat pump 10 comprises a condenser 11, an expansion valve 12, an evaporator 13, a compressor 14, and a refrigeration circuit 15. The refrigeration circuit 15 contains a refrigerant. The condenser 11, the expansion valve 12, the evaporator 13, and the compressor 14 are arranged successively in the refrigeration circuit 15 and are thus traversed by the refrigerant.
[0041] The refrigerant is compressed, preferably in a gaseous state, in the compressor 14. As a result, the temperature of the refrigerant is increased by the compressor 14. In the condenser 11, the refrigerant transfers its heat to the fluid to be heated contained in the internal volume 4 of the tank 2. The refrigerant condenses in the condenser 11, in order to transfer, in particular, heat of phase change to the fluid to be heated contained in the internal volume 4 of the tank 2. The pressure of the refrigerant, preferably in a liquid state at the inlet of the expansion valve 12, decreases in the expansion valve 12. As a result, the temperature of the refrigerant decreases in the expansion valve 12. In the evaporator 13, the refrigerant exchanges heat with the environment to absorb heat energy from the environment, which may be the air or the ground. or a water source.
[0042] Thus, the heat energy from the environment is transferred to the fluid to be heated contained in the internal volume 4 of the tank 2, via the refrigerant, by supplying, generally with electrical energy, the compressor 14.
[0043] As illustrated in [Fig. 1], the condenser 11 comprises a tube 20 extending between a first end 20a and a second end 20b. The tube 20 is wound around the outer surface of the tank 3. The tube 20 comprises a succession of turns extending around the outer surface of the tank 3. In the illustrated embodiment, the tube 20 comprises ten turns between the first end 20a through which the refrigerant enters the condenser 11 and the second end 20b through which the refrigerant exits the condenser 11. The pitch of each turn is preferably between 30 millimeters and 100 millimeters, advantageously the pitch of the turns is 48 millimeters ±10%.
[0044] As illustrated in Figures 2 and 3, the tube 20 has an inner surface of tube 22 and an outer surface of tube 24, between which a wall of tube 21 is defined. The inner surface of tube 22 defines a passage 25, which forms part of the refrigeration circuit and contains the refrigerant. The passage 25 is unique. The outer surface of tube 24 has a flat outer portion 24a. The flat outer portion 24a is flat and continuously supported against the outer surface of tank 3 between the first end 20a and the second end 20b.
[0045] The outer flat portion 24a extends along the longitudinal direction X over a bearing length d. The bearing length is preferably equal to 8.3 millimeters ±10%.
[0046] The inner surface of tube 22 has an inner flat portion 22a parallel to the outer flat portion 24a and separated from the outer flat portion 24a by the tube wall 21.
[0047] The passage 25 extends along the longitudinal direction X over a distance D advantageously greater than 5.4 millimeters, preferably greater than 6.4 millimeters, more preferably greater than 7.4 millimeters. Ideally, the distance D is equal to 8.7 millimeters ±10%.
[0048] As illustrated in figures 2 and 3, passage 25 has a cross-sectional area A. The area A is preferably equal to 16 mm2±10% (square millimeters to the nearest ten percent).
[0049] The ratio between the area A and the support length d is less than 2, preferably equal to 1.81 mm ± 10%.
[0050] Thus, a compromise is reached aimed at:
[0051] limit the pressure drop of the refrigerant against the inner surface of tube 22, which tends in particular to increase the area A,
[0052] ensure good thermal conduction between the tube 20 and the fluid to be heated contained in the internal volume 4 of the tank 2, which tends to increase the support length d,
[0053] limit the refrigerant charge, which tends to reduce area A.
[0054] The tube wall 21 has a substantially constant thickness e. The thickness e The thickness is advantageously between 0.8 mm and 2 mm, preferably between 1.1 mm and 1.6 mm. The thickness e is defined to be greater than or equal to a minimum thickness below which the tube risks undergoing plastic deformation at the nominal operating pressure (generally, at the maximum water temperature in the tank). A margin between the thickness e and said minimum thickness improves the robustness of the device by reducing the risk of an increase in the heat exchanger volume due to the pressure cycles that the tube 22 undergoes during its service life.
[0055] The ratio A / (de) is preferably less than or equal to 1.5, more preferably less than 1.4.
[0056] The tube 20 is preferably extruded and then wound into spirals. The tube 20 is preferably made of aluminum or aluminum alloy.
[0057] The refrigerant has a global warming potential (GWP), in other words a ratio between the tonne of CO2 equivalent of the refrigerant and the tonne of refrigerant, of less than 50. Preferably, the refrigerant is propane (R290) whose global warming potential (GWP) is approximately equal to 3.
[0058] In the embodiment illustrated in [Fig.2], the outer surface of tube 24 has in cross-section, in addition to the outer flat portion 24a, an outer circular portion 24b which is opposite (opposite to) the outer flat portion 24a.
[0059] The inner surface of the tube 22 has, in cross-section, in addition to the inner flat portion 22a, an inner circular portion 22b which connects directly to the inner flat portion 22a. The inner circular portion 22b is parallel to the outer circular portion 24b and separated from the outer circular portion 24b by the wall 21.
[0060] The inner circle portion 22b and the outer circle portion 22b each represent a portion of angle a between 60 degrees and 90 degrees.
[0061] Rounded fillets 22d with a radius less than 1 millimeter, preferably about 0.4 millimeters in radius, connect the inner flat portion 22a and the inner circular portion 22b.
[0062] At the apex (in the middle) of the inner circular portion 22b, the inner circular portion 22b is separated from the inner flat portion 22a by a distance at the apex 1 preferably equal to 2.3 mm ± 10%.
[0063] In the embodiment illustrated in [Fig.3], the outer flat portion 24a forms a first outer flat portion and the outer surface of tube 24 also has, in cross-section, a second outer flat portion 24c which is opposite the first outer flat portion 24a, in other words opposite the first outer flat portion 24a.
[0064] The inner flat portion 22a forms a first inner flat portion separated from The first external flat portion 24a is formed by the wall 21. The inner surface of the tube 22 also has, in cross-section, a second internal flat portion 22c which is opposite the first internal flat portion 22a and parallel to the first internal flat portion 22a. The second internal flat portion 22c is preferably 1.8 mm ± 10% from the first internal flat portion 22a. The second external flat portion 22c is joined to the first internal flat portion 22a by two semicircular fillets, preferably with a radius of 0.9 mm ± 10%. As in the embodiment illustrated in [Fig. 2], the bearing length is preferably 8.3 mm ± 10% and the area A is preferably 16 mm² ± 10% (square millimeters to the nearest ten percent).
Claims
Demands
1. A thermodynamic heating device (1) comprising: a tank (2), said tank (2) having an internal volume (4), an inlet port (6), an outlet port (8), and an external tank surface (3), the internal volume (4) being configured to contain a fluid to be heated intended to enter the internal volume (4) through the inlet port (6) and exit the internal volume (4) through the outlet port (8), the external tank surface (3) extending along a longitudinal direction (X), and a heat pump (10), the heat pump (10) having a refrigeration circuit (15) in which a refrigerant fluid is intended to circulate, the heat pump (10) including a condenser (11), the condenser (11) having a tube (20), the tube (20) being extruded and wound around the external tank surface (3), said tube (20) having an internal tube surface (22) and a outer surface of tube (24),The inner surface of tube (22) and the outer surface of tube (24) define a tube wall (21). The inner surface of tube (22) defines a single passage (25) containing the refrigerant. The outer surface of tube (24) has a flat external portion (24a) bearing against the outer surface of the tank (3). The device is characterized in that the passage (25) has a cross-section with the following characteristics: an area (A) of less than 35 square millimeters, the flat external portion (24a) extending along the longitudinal direction (X) over a bearing length (d) of more than 5 millimeters, a ratio between area (A) and the bearing length (d) of less than 2 millimeters, the tube wall has a thickness (e) between 0.8 millimeters and 2 millimeters, and the ratio (A / (de)) is between the area (A) and the product of the length support (d) and thickness (e) is less than or equal to 1.5,preferably less than 1.
4.
2. Device according to claim 1 in which the area (A) is less than 25 square millimeters, preferably less than 20 square millimeters.
3. Device according to any one of the preceding claims wherein the bearing length (d) is greater than 6 millimeters, preferably greater than 7 millimeters.
4. Device according to any one of the preceding claims wherein the outer surface of tube (24) has in cross-section an outer circular portion (24b), the outer circular portion (24b) is opposite the outer flat portion (24a) and connects to the outer flat portion (24a).
5. Device according to the preceding claim in which the outer circular portion (24a) represents less than 1 / 4 of a circle.
6. Device according to any one of claims 1 to 3 wherein the outer flat portion (24a) forms a first outer flat portion, the outer surface of tube (24) has a second outer flat portion (24c), the second outer flat portion (24c) is opposite the first outer flat portion (24a), parallel to the first outer flat portion (24a) and connects to the first outer flat portion (24a).
7. Device according to any one of the preceding claims in which the refrigeration circuit (15) contains less than 160 grams of refrigerant.
8. Device according to any one of the preceding claims wherein the refrigerant is propane.
9. Device according to any one of the preceding claims wherein the tube wall has a thickness (e) between 1.1 millimeters and 1.6 millimeters.
10. Device according to any one of the preceding claims wherein the internal volume (4) of the tank (2) is between 80 liters and 300 liters.
11. Device according to any one of the preceding claims wherein the device is a storage water heater (1).