Multifunctional thermal plant, comprising a heat pump with a reduced amount of refrigerant

Abstract

The present invention relates to a thermal installation (10) comprising: a refrigerant circuit (20); a compressor (22), a condenser (24), a first (26) and a second (28) heat exchangers, and a first expansion valve (30), arranged on said circuit; and a first connection device (34), arranged on said circuit. In a first and a second configuration of the first connection device, the refrigerant transfers energy to the condenser and the second heat exchanger, respectively. The installation further comprises a second expansion valve (32) and a second connection device (36), arranged on the circuit. In a first and a second configuration of the second connection device, the refrigerant absorbs energy from the first and second heat exchangers, respectively.

Description

[0001] The present invention relates to a thermal installation, of the type comprising a heat pump, said heat pump comprising: a refrigerant circuit; a compressor, a condenser, a first and a second heat exchanger, and a first expansion valve, arranged on said circuit; and a first connection device, arranged on said circuit; the installation being configured so that, in a first configuration of the first connection device, the compressor is connected to the condenser to allow the refrigerant to transfer energy to said condenser; and in a second configuration of the first connection device, the compressor is connected to the second heat exchanger to allow the refrigerant to transfer energy to said second heat exchanger.

[0002] The invention applies particularly to thermal installations for residential type buildings.

[0003] In individual homes, it is known to implement thermal systems equipped with a heat pump, in particular to ensure the thermal regulation of the building and the heating of domestic hot water. Heat pumps reduce energy consumption by a factor of 3 to 4 compared to fossil fuel heating such as a gas or oil boiler. In addition, the use of heat pumps helps reduce the carbon footprint of the building.

[0004] Traditionally, thermal installations with heat pumps use a fluorinated refrigerant, such as HFC-134a. Such compounds allow for charges greater than 1 kg of refrigerant, which is suitable for a high-volume circuit. However, fluorinated compounds have a significant environmental impact, measured by the global warming potential (GWP).

[0005] Other refrigerants, such as hydrocarbons like isobutane or propane, have a much lower GWP. However, these compounds are typically toxic or flammable. These constraints lead to limiting the maximum charge to a small amount, particularly around 150 g, in installations without minimum surface area or ventilation requirements. Such operating conditions make non-fluorinated compounds incompatible with high volumes of refrigerant circuits.

[0006] It is therefore advantageous to design heat pumps in thermal installations so that they only require a reduced quantity of refrigerant. Such a thermal installation is described in particular in document FR3124586 in the name of the Applicant.

[0007] Furthermore, in order to optimize the thermal regulation of the building, it is advantageous to have a reversible heat pump, allowing the indoor air to be heated or cooled as needed.

[0008] The aim of the present invention is to propose a thermal installation capable of providing several functions, such as domestic heating, air conditioning and heating of domestic water, while requiring a reduced quantity of refrigerant.

[0009] To this end, the invention relates to a thermal installation of the aforementioned type, in which the heat pump further comprises: a second expansion valve arranged on the refrigerant circuit; and a second connection device, arranged on said circuit; and in that the installation is configured so that, in a first configuration of the second connection device, the first expansion valve is arranged upstream of the first heat exchanger, to allow the refrigerant to draw energy from said first heat exchanger; and in a second configuration of the second connection device, the second expansion valve is arranged upstream of the second heat exchanger, to allow the refrigerant to draw energy from said second heat exchanger.

[0010] According to other advantageous aspects of the invention, the thermal installation comprises one or more of the following characteristics, taken individually or in all technically possible combinations: in a third configuration of the first connection device, the compressor is connected to the first heat exchanger to allow the refrigerant to transfer energy to said first heat exchanger; the first connection device comprises a first four-way valve; and in the first and second configurations of said first connection device, said first four-way valve is respectively in a first and a second position; in the third configuration of the first connection device, the first four-way valve is in the second position; the first connection device further comprises at least a first single valve; and in the second configuration of said first connection device, said first single valve is closed; the first connection device further comprises at least a second single valve;and in the third configuration of said first connection device, said second single valve is closed; the second connection device comprises a second four-way valve; and in the first and second configurations of said second connection device, said first four-way valve is respectively in a first and in a second position; the second connection device further comprises a first and a second non-return valve, arranged on the refrigerant circuit, respectively between the first expansion valve and the first heat exchanger and between the second expansion valve and the second heat exchanger. ;

[0011] The invention further relates to a method of operating a thermal installation as described above, comprising: a first mode in which each of the first and second connection devices is in the first configuration and the refrigerant takes energy from the first heat exchanger and transfers energy to the condenser; a second mode in which the first connection device is in the second configuration, the second connection device is in the first configuration, and the refrigerant takes energy from the first heat exchanger and transfers energy to the second heat exchanger; and a third mode in which the second connection device is in the second configuration and the refrigerant takes energy from the second heat exchanger.

[0012] According to other advantageous aspects of the invention, the thermal installation comprises one or more of the following characteristics, taken individually or in all technically possible combinations: in the third mode, the first connection device is in the third configuration and the refrigerant transfers energy to the first heat exchanger; the operating method further comprises a fourth mode in which: the second connection device is in the second configuration; and the first connection device is configured such that the refrigerant transfers energy to the condenser.

[0013] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which: there figure 1 is a schematic representation of a thermal installation according to an embodiment of the invention, in an operating mode; and the figure 2 is a schematic representation of the thermal installation of the figure 1 , in another mode of operation.

[0014] THE figures 1 And 2 show a thermal installation 10 according to one embodiment of the invention.

[0015] The thermal installation 10 is integrated into a building 12, for example a dwelling.

[0016] The thermal installation 10 comprises a heat pump 14 intended to ensure both thermal regulation and heating of the domestic hot water of the building 12. For this purpose, the thermal installation 10 further comprises: a domestic hot water circuit 16, comprising in particular a tank 17; and a thermal regulation fluid circuit 18.

[0017] The heat pump 14 comprises: a refrigerant circuit 20; a compressor 22; a condenser 24; a first 26 and a second 28 reversible heat exchanger; a first 30 and a second 32 expansion valve; a first 34 and a second 36 connection device; and an electronic control module 38.

[0018] Preferably, the heat pump 14 further comprises one or more elements chosen from: a first and a second bulb 40, each bulb being connected by a capillary tube to one of the first 30 and second 32 expansion valves; a dehydrator filter 42; and one or more pressure and / or temperature probes 44, 45, 46.

[0019] The refrigerant circuit 20 comprises a plurality of branches connected to each other by a plurality of junctions. In the embodiment shown, the refrigerant circuit 20 comprises a first 47 and a second 48 junction called “X” and six junctions 51, 52, 53, 54, 55, 56 called “T”. By X and T junction is meant a junction joining respectively four branches and three branches of the circuit 20.

[0020] The compressor 22, the condenser 24, the first 26 and second 28 exchangers and the first 30 and second 32 expanders are arranged on the circuit 20.

[0021] The compressor 22 is capable of compressing the refrigerant of the circuit 20. More precisely, when said compressor is in operation, low-pressure gaseous refrigerant enters said compressor and leaves at high pressure. The compressor 22 thus determines a direction of circulation of the refrigerant in the circuit 20.

[0022] The compressor 22 is in communication with the electronic module 38, said module being capable of controlling the operation of said compressor.

[0023] In the embodiment shown, a pressure sensor 44 is arranged on the circuit 20 downstream of the compressor 22, i.e. on the high pressure side. Said pressure sensor 44 is also in communication with the electronic module 38.

[0024] The upstream of the compressor 22, i.e. the low pressure side of said compressor, is connected to a first T-junction 51 of said circuit.

[0025] The condenser 24 is arranged in thermal contact with the domestic hot water tank 17, so as to transfer heat to said domestic hot water. The condenser 24 is preferably designed with a reduced internal volume to require only a small quantity of refrigerant. This is for example a condenser as described in document FR2963416 in the name of the Applicant.

[0026] On the refrigerant circuit 20, a first end of the condenser 24 is connected to the first X-shaped junction 47.

[0027] In the embodiment shown, the first exchanger 26 is an air / refrigerant heat exchanger. Said first exchanger 26 is connected or arranged outside the building 12. Preferably, the first exchanger 26 is equipped with a first fan 58 capable of generating an outside air flow through said first exchanger.

[0028] On the refrigerant circuit 20, the ends of the first exchanger 26 are connected respectively to a second 52 and to a third 53 T-junction.

[0029] The second exchanger 28 is capable of exchanging heat with the thermal regulation fluid circuit 18. In the embodiment shown, the second exchanger 28 is an air / refrigerant heat exchanger; and the fluid circuit 18 is an air circuit circulating inside the building 12. Preferably, the second exchanger 28 is equipped with a second fan 60, capable of generating an interior air flow in the circuit 18. Optionally, the circuit 18 is equipped with a solid particle filter 62, located upstream of the second exchanger 28.

[0030] On the refrigerant circuit 20, the ends of the second exchanger 28 are connected respectively to a fourth 54 and to a fifth 55 T-junction.

[0031] As detailed below, each of the first 26 and second 28 exchangers is a reversible heat exchanger, capable of operating in condenser mode or in evaporator mode.

[0032] Preferably, the first 26 and second 28 exchangers are designed with a reduced internal volume to require only a small quantity of refrigerant.

[0033] Preferably, the first 58 and second 60 fans are in communication with the electronic module 38.

[0034] The first regulator 30 is located near the first exchanger 26. More precisely, a first end of said first regulator 30 is connected to the second T-junction 52.

[0035] The second regulator 32 is located near the second exchanger 28. More precisely, a first end of said second regulator 32 is connected to the fourth T-junction 54.

[0036] The first connection device 34 comprises a first four-way valve 64 and several two-way valves 66, 68, 70, 72, or single valves. Preferably, the first four-way valve 64 and the single valves 66, 68, 70, 72 are solenoid valves, in communication with the electronic control module 38.

[0037] The first four-way valve 64 is connected downstream of the compressor 22, to the second end of the condenser 24, to the first T-junction 51 and to a sixth T-junction 56.

[0038] In the embodiment shown, the first connection device 34 comprises four single valves 66, 68, 70, 72. A first single valve 66 is connected to the third 53 and sixth 56 T-junctions. A second single valve 68 is connected to the fifth 55 and sixth 56 T-junctions. A third 70 and a fourth 72 single valves are both connected to the second X-junction 48. Furthermore, said third 70 and fourth 72 valves are connected respectively to the third 53 and fifth 55 T-junctions.

[0039] The second connection device 36 comprises a second four-way valve 74 and several non-return valves 75, 76, 77, 78, 79. Preferably, the second four-way valve 74 is a solenoid valve, in communication with the electronic control module 38.

[0040] The second four-way valve 74 is connected to the second end of each of the first 30 and second 32 pressure reducers, as well as to the first 47 and second 48 X-junctions. In the embodiment shown, a filter drier 42 is interposed between the second four-way valve 74 and the first X-junction 47.

[0041] In the embodiment shown, the second connection device 36 comprises five non-return valves 75, 76, 77, 78, 79.

[0042] A first 75 and a second 76 valve are arranged respectively between the first regulator 30 and the second T-junction 52, and between the second regulator 32 and the fourth T-junction 54. Each of said valves 75, 76 prevents the circulation of fluid from said junction 52, 24 to said regulator 30, 32.

[0043] A third valve 77 is disposed between the first X-shaped junction 47 and the second T-shaped junction 52. A fourth valve 78 is disposed between the first X-shaped junction 47 and the fourth T-shaped junction 54. A fifth valve 79 is disposed between the first X-shaped junction 47 and the first end of the condenser 24.

[0044] Each of the third 77, fourth 78 and fifth 79 valves prevents the circulation of fluid from the first junction 47 in X.

[0045] Finally, the second X junction 48 is connected to the first T junction 51.

[0046] On the figure 1 , the first four-way valve 64 is in a first position. In said first position of the first valve 64, the downstream of the compressor 22 is connected to the second end of the condenser 24; and the first 51 and sixth 56 T-junctions are connected to each other.

[0047] On the figure 2 , the first four-way valve 64 is in a second position. In said second position of the first valve 64, the downstream of the compressor 22 is connected to the sixth T-junction 56; and the first T-junction 51 is connected to the second end of the condenser 24.

[0048] On the figure 1 , the second four-way valve 74 is in a first position. In said first position of the second valve 74, the first X-shaped junction 47 is connected to the first regulator 30; and the second X-shaped junction 48 is connected to the second regulator 32.

[0049] On the figure 2 , the second four-way valve 74 is in a second position. In said second position of the second valve 74, the first X-junction 47 is connected to the second regulator 32; and the second X-junction 48 is connected to the first regulator 30.

[0050] A method of operating the installation 10 will now be described. Said method is implemented by a program stored in the electronic module 38. The program allows said electronic module 38 to control the compressor 22, the solenoid valves 64, 66, 68, 70, 72, 74 and possibly the fans 58, 60, as described below.

[0051] According to said method, several operating modes of the installation 10, described below, are applied depending on the thermal needs of the building 12.

[0052] A first operating mode allows the production of domestic hot water by taking heat from the air outside building 12.

[0053] For this purpose, the first connection device 34 is in a first configuration. In said first configuration, the first four-way valve 64 is in the first position of the figure 1 ; and at least the second 68 and third 70 single valves are open. Preferably, in said first configuration, the first 66 and fourth 72 single valves are also open, in order to limit the electrical consumption of said valves.

[0054] Furthermore, in the first mode of operation, the second four-way valve 74 is in the first position of the figure 1 .

[0055] The compressor 22 in operation therefore sends gaseous refrigerant, under high pressure, to the first four-way valve 64. Said first valve directs said refrigerant to the condenser 24. Said fluid then gives off heat to the water in the tank 17 by condensing into the liquid state.

[0056] The refrigerant then reaches the first expansion valve 30 via the second four-way valve 74 and then drops in pressure. Said fluid then passes through the first exchanger 26. Said first exchanger then operates in evaporator mode, the refrigerant taking heat from the outside air while passing into the gaseous state.

[0057] The fluid in the gaseous state at low pressure then joins the upstream of the compressor by passing through the first single valve 66.

[0058] Furthermore, in the first operating mode, the second exchanger 28 is subjected to the low pressure of the compressor 22 via the second single valve 68. The residual refrigerant in the second exchanger 28 is therefore in the gaseous state, which minimizes its quantity.

[0059] A second operating mode allows the indoor air of building 12 to be heated by taking heat from the outdoor air.

[0060] For this purpose, the first connection device 34 is in a second configuration. In said second configuration, the first four-way valve 64 is in the second position of the figure 2 ; the second 68 and third 70 single valves are open; and the first 66 and fourth 72 single valves are closed.

[0061] Furthermore, in the second mode of operation, the second four-way valve 74 is in the first position of the figure 1 .

[0062] In the second operating mode, the high-pressure gaseous refrigerant is directed to the second exchanger 28 by the first four-way valve 64 and the second single valve 68. Said second exchanger 28 then operates in condenser mode, the refrigerant giving off heat to the interior air circuit 18 while condensing.

[0063] The refrigerant is then sent through the second four-way valve 74 to the first expansion valve 30, in which it drops in pressure. It then passes through the first exchanger 26 in evaporator mode. Said fluid takes heat from the outside air by evaporating. The low-pressure gaseous fluid then reaches the upstream side of the compressor by passing through the third single valve 70.

[0064] Furthermore, in the second mode of operation, the condenser 24 is subjected to the low pressure of the compressor 22 via the first four-way valve 64. The residual refrigerant in the condenser 24 is therefore in the gaseous state, which minimizes its quantity.

[0065] A third mode of operation allows the air inside the building to be cooled by transferring heat to the outside air.

[0066] For this purpose, the first connection device 34 is in a third configuration. In said third configuration, the first four-way valve 64 is in the second position of the figure 2 ; the second 68 and third 70 single valves are closed; and the first 66 and fourth 72 single valves are open.

[0067] Furthermore, in the third mode of operation, the second four-way valve 74 is in the second position of the figure 2 .

[0068] In the third operating mode, the high-pressure gaseous refrigerant is directed to the first exchanger 26, by the first four-way valve 64 and the first single valve 66. Said first exchanger 26 then operates in condenser mode, the refrigerant gives off heat to the outside air by condensing.

[0069] The refrigerant is then sent by the second four-way valve 74 to the second expansion valve 32, in which it drops in pressure, then it passes through the second exchanger 28. Said second exchanger then operates in evaporator mode, the refrigerant taking heat from the interior air circuit 18 while evaporating. The fluid in the low-pressure gaseous state then joins the upstream of the compressor by passing through the fourth single valve 72.

[0070] Furthermore, in the third mode of operation, the condenser 24 is subjected to the low pressure of the compressor 22 via the first four-way valve 64. The residual refrigerant in the condenser 24 is therefore in the gaseous state, which minimizes its quantity.

[0071] A fourth operating mode allows the production of domestic hot water by taking heat from the air inside building 12, so as to cool said indoor air.

[0072] For this purpose, the first connection device 34 is in a fourth configuration. In said fourth configuration, the first four-way valve 64 is in the first position of the figure 1 ; and at least the first 66 and second 68 single valves are open.

[0073] Preferably, in said fourth configuration, the third 70 and fourth 72 single valves are also open, in order to limit the electrical consumption of said valves. The fourth configuration of the first connection device 34 is thus identical to the first configuration described above.

[0074] Furthermore, in the fourth mode of operation, the second four-way valve 74 is in the second position of the figure 2 .

[0075] In the fourth mode of operation, the high-pressure gaseous refrigerant is directed to the condenser 24, through the first four-way valve 64. The refrigerant gives off heat to the water in the tank 17 by condensing.

[0076] The refrigerant is then sent by the second four-way valve 74 to the second expansion valve 32, in which it drops in pressure, then passes through the second exchanger 28 in evaporator mode. The refrigerant takes heat from the indoor air circuit 18 while evaporating. The low-pressure gaseous fluid then joins the upstream of the compressor by passing through the second single valve 68.

[0077] Furthermore, in the fourth operating mode, the first heat exchanger 26 is subjected to the low pressure of the compressor 22 via the first four-way valve 64 and the first single valve 66. The residual refrigerant in the first exchanger 26 is therefore in the gaseous state, which minimizes its quantity.

[0078] The installation 10 is therefore configured to operate in four distinct modes. Each mode makes it possible to isolate and empty the unused part of the refrigerant circuit via the non-return valves 75, 76, 77, 78, 79 and via the appropriate positions of the solenoid valves 64, 66, 68, 70, 72, 74.

[0079] Such a configuration of the installation 10 makes it possible to minimize the quantity of refrigerant fluid necessary for the operation of the installation. In particular, it is possible to size the installation 10 to operate with a propane charge (R290) less than or equal to 150 g. It is thus possible to equip a building 12 with the installation 10 without constraints on the surface area and ventilation of said building.

[0080] Furthermore, installation 10 makes it possible to combine an air conditioning function with the heating and domestic hot water functions, for better thermal comfort in building 12.

Claims

1. Thermal installation (10) comprising a heat pump (14), said heat pump comprising: - a refrigerant circuit (20); - a compressor (22), a condenser (24), a first (26) and a second (28) heat exchanger, and a first expansion valve (30), arranged on said circuit; and - a first connection device (34), arranged on said circuit; the installation being configured so that, in a first configuration of the first connection device, the compressor (22) is connected to the condenser (24) to allow the refrigerant to transfer energy to said condenser; and in a second configuration of the first connection device, the compressor is connected to the second heat exchanger (28) to allow the refrigerant to transfer energy to said second heat exchanger; the thermal installation being characterized in thatthe heat pump further comprises: - a second expansion valve (32) arranged on the refrigerant circuit; and - a second connection device (36), arranged on said circuit; and in that the installation is configured so that, in a first configuration of the second connection device, the first expansion valve (30) is arranged upstream of the first heat exchanger (26), to allow the refrigerant to draw energy from said first heat exchanger; and in a second configuration of the second connection device, the second expansion valve (32) is arranged upstream of the second heat exchanger (28), to allow the refrigerant to draw energy from said second heat exchanger.

2. Thermal installation according to claim 1, in which, in a third configuration of the first connection device (34), the compressor (22) is connected to the first heat exchanger (26) to allow the refrigerant to release energy to said first heat exchanger.

3. Thermal installation according to claim 1 or 2, wherein: the first connection device comprises a first four-way valve (64); and in the first and second configurations of said first connection device (34), said first four-way valve is respectively in a first and in a second position.

4. Thermal installation according to claim 3 taken in combination with claim 2, wherein, in the third configuration of the first connection device (34), the first four-way valve (64) is in the second position.

5. Thermal installation according to one of claims 3 or 4, in which: the first connection device (34) further comprises at least one first single valve (66, 72); and in the second configuration of said first connection device, said first single valve is closed.

6. Thermal installation according to one of claims 3 to 5 taken in combination with claim 2, in which: the first connection device further comprises at least one second single valve (68, 70); and in the third configuration of said first connection device, said second single valve is closed.

7. Thermal installation according to one of the preceding claims, in which: the second connection device (36) comprises a second four-way valve (74); and in the first and second configurations of said second connection device, said first four-way valve is respectively in a first and in a second position.

8. Thermal installation according to claim 7, in which the second connection device (36) further comprises a first (75) and a second (76) non-return valve, arranged on the refrigerant circuit, respectively between the first expansion valve (30) and the first heat exchanger (26) and between the second expansion valve (32) and the second heat exchanger (28).

9. A method of operating a thermal installation (10) according to one of the preceding claims, comprising: - a first mode in which: each of the first (34) and second (36) connection devices is in the first configuration; and the refrigerant takes energy from the first heat exchanger (26) and transfers energy to the condenser (24); - a second mode in which: the first connection device (34) is in the second configuration; the second connection device (36) is in the first configuration; and the refrigerant takes energy from the first heat exchanger (26) and transfers energy to the second heat exchanger (28); and - a third mode in which: the second connection device (36) is in the second configuration; and the refrigerant takes energy from the second heat exchanger (28).

10. Operating method according to claim 9, of a thermal installation according to claim 2, such that, in the third mode, the first connection device (34) is in the third configuration and the refrigerant transfers energy to the first heat exchanger (26).

11. The method of operation of claim 10, further comprising a fourth mode wherein: the second connection device (36) is in the second configuration; and the first connection device (34) is configured such that the refrigerant transfers energy to the condenser (24).

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