Heat pump module, plant comprising such heat pump module and method for heating a substance

Abstract

Heat pump module (1), comprising: a first circuit (2) for a first refrigerant fluid and a second circuit (3) for a second refrigerant fluid; a first heat exchanger (4) arranged on the first circuit (2) for heat exchange between the first refrigerant fluid and a first heat transfer fluid; a first compressor (5) arranged on the first circuit (2) downstream of the first heat exchanger (4); a second heat exchanger (6) interposed between the first circuit (2) and the second circuit (3) for heat exchange between the first refrigerant fluid and the second refrigerant fluid, said second heat exchanger (6) being located on the first circuit (2) downstream of the first compressor (5); a first expansion valve (7) arranged on the first circuit (2) downstream of the second heat exchanger (6); a second compressor (8) arranged on the second circuit (3) downstream of the second heat exchanger (6); a third heat exchanger (9) arranged on the second circuit (3) downstream of the second compressor (8) for heat exchange between the second refrigerant fluid and a second heat transfer fluid.

Description

[0001] DESCRIPTION

[0002] Title: “Heat pump module, plant comprising such heat pump module and method for heating a substance”

[0003] The present invention relates to a heat pump module, a plant comprising such heat pump module and a method for heating a substance.

[0004] As is known, a heat pump is a device that extracts heat from one or more low-temperature sources to supply it to one or more high-temperature sources, with the aid of an external source of energy.

[0005] Heat pumps are designed to move heat energy in the direction opposite to that of the spontaneous flow of heat, by absorbing heat from a cold space and releasing it into a warmer one.

[0006] Underlying the operation of a heat pump is the use of a volatile fluid that evaporates and condenses, known as a refrigerant fluid.

[0007] The compressor of a heat pump draws the refrigerant fluid in the form of a gas, compressing it in the high-pressure zone of the circuit. The compressed gas is pushed into a first heat exchanger (condenser), where it transfers heat to the environment and cools until condensing into liquid form. The liquid is pushed through an expansion valve that separates the high-pressure part from the low-pressure part of the circuit. When the liquid, now at a low pressure, reaches a second heat exchanger (evaporator), it absorbs heat from the environment and passes into gaseous form so as to be again drawn in by the compressor, starting the cycle over again.

[0008] Typically, a heat pump uses a refrigerating cycle to remove heat from a low- temperature source and return it to a higher thermal level in order to enable an effective use of its heat content at temperatures suitable for a thermal utility.

[0009] However, the delivery temperatures that are reached by a standard heat pump are between 70°C and 80°C. This makes it unsuitable for use in a variety of applications, including for example the chemical industry, where it is necessary to reach higher temperatures (e.g. 130°C - 180°C). For this reason, to date, electric or gas heating systems are used, with high energy expenditure.

[0010] In this context, the technical task underpinning the present invention is to propose a heat pump module, a plant comprising such heat pump module and a method for heating a substance, which obviate the drawbacks of the prior art cited above.

[0011] In particular, an aim of the present invention is to propose a heat pump module, a plant comprising such heat pump module and a method for heating a substance which are suitable for producing temperatures comprised between 130°C and 185°C.

[0012] Another aim of the present invention is to make available a heat pump module, a plant comprising such heat pump module and a method for heating a substance, capable of producing both a hot heat transfer fluid and a cold heat transfer fluid with the same energy expenditure as the known solutions that produce only a hot heat transfer fluid.

[0013] The stated technical task and specified aims are substantially achieved by a heat pump module comprising the technical features set forth in one or more of the appended claims.

[0014] The stated technical task and specified aims are substantially achieved by a plant comprising the technical features set forth in one or more of the appended claims.

[0015] The stated technical task and specified aims are substantially achieved by a method for heating a substance comprising the technical features set forth in one or more of the appended claims.

[0016] Further features and advantages of the present invention will become more apparent from the indicative and thus non-limiting description of a preferred, but not exclusive, embodiment of a heat pump module, a plant comprising such heat pump module and a method for heating a substance, as illustrated in the appended figure 1 , which illustrates a plant, according to the present invention, comprising a heat pump module, in schematic view. With reference to the figure, number 1 indicates a heat pump module. The present invention finds its main, but not exclusive, use in the chemical industry. In general, the heat pump module 1 is used in various applications, ranging from the chemical, pharmaceutical, petrochemical, surface treatment, food industry, and to the production of polymers and plastics (non-exhaustive list) in order to bring a heat source up to a temperature of 185°C and a source of water added with glycol or other cooled fluid to a temperature comprised between 5°C and 10°C.

[0017] The heat pump module 1 comprises a first circuit 2 for a first refrigerant fluid and a second circuit 3 for a second refrigerant fluid.

[0018] The heat pump module 1 comprises a first heat exchanger 4 arranged along the first circuit 2. Preferably, the first heat exchanger 4 comprises an inlet 4a and an outlet 4b for the first refrigerant fluid. Preferably, the first heat exchanger 4 comprises an inlet 4c and an outlet 4d for a first heat transfer fluid.

[0019] The first heat exchanger 4 is an evaporator. The heat exchange between the first refrigerant fluid and the first heat transfer fluid is such that the first refrigerant fluid passes into the gaseous state.

[0020] The first heat transfer fluid is often identified as a “cold source” as a refrigerant fluid with a low boiling point is used, therefore a low-temperature fluid can be used. The cold source is usually water, to which glycol may be added, or another fluid. Typically, the inlet temperature is between 10°C and 25°C and the outlet temperature between 5°C and 10°C.

[0021] In one embodiment, the first heat transfer fluid, for example water, enters the first heat exchanger 4 at about 12°C and exits at about 7°C.

[0022] For these reasons, it is possible to refer to the first heat transfer fluid as “cold heat transfer fluid”.

[0023] The heat pump module 1 comprises at least a first compressor 5 arranged downstream of the first heat exchanger 4. In one embodiment, the heat pump module 1 comprises at least two first compressors 5 in series. The heat pump module 1 comprises a second heat exchanger 6. The second heat exchanger 6 is interposed between the two circuits 2, 3. In particular, the second heat exchanger 6 is shared between the first and the second circuit 2, 3. In other words, the second heat exchanger 6 acts on the first circuit 2 and on the second circuit 3.

[0024] The second heat exchanger 6 is arranged on the first circuit 2 downstream of the first compressor 5. The heat exchange between the first refrigerant fluid and the second refrigerant fluid takes place in the second heat exchanger 6, as will be better described below.

[0025] Preferably, the second heat exchangers comprises an inlet 6a and an outlet 6b for the first refrigerant fluid. Preferably, the second heat exchanger 6 comprises an inlet 6c and an outlet 6d for the second refrigerant fluid.

[0026] The heat pump module 1 comprises a first expansion valve 7 arranged on the first circuit 2 between the outlet 6b of the second heat exchanger 6 and the inlet 4a of the first heat exchanger 4.

[0027] The heat pump module 1 comprises at least one second compressor 8 arranged on the second circuit 3 downstream of the second heat exchanger 6. In one embodiment, the heat pump module 1 comprises at least two second compressors 8 in series.

[0028] The heat pump module 1 comprises a third heat exchanger 9 arranged on the second circuit 3 downstream of the second compressor 8. Preferably, the third heat exchanger 9 comprises an inlet 9a and an outlet 9b for the second refrigerant fluid. Preferably, the third heat exchanger 9 comprises an inlet 9c and an outlet 9d for a second heat transfer fluid.

[0029] The second heat transfer fluid is a fluid intended to receive heat from the heat pump module 1 in order to carry it to a destination in which it transfers heat, directly or indirectly, to a substance.

[0030] In contrast with the first heat transfer fluid, the second heat transfer fluid is identified as a “hot heat transfer fluid”.

[0031] Preferably, the third heat exchanger 9 is of the flooded type. In this way, it also performs the function of a liquid receiving device. The heat pump module 1 comprises a second expansion valve 14 arranged on the second circuit 3 between the outlet 9b of the third heat exchanger 9 and the inlet 6c of the second heat exchanger 6.

[0032] Preferably, the heat pump module 1 comprises the first refrigerant fluid flowing in the first circuit 2 and the second refrigerant fluid flowing in the second circuit 3.

[0033] Preferably, the heat pump module 1 is configured such that the second heat transfer fluid is brought into the third heat exchanger 9 at temperatures comprised between 80°C and 125°C.

[0034] By way of non-limiting example, the second heat transfer fluid may be open- or closed-vessel diathermic oil, inhibited calcium carbonate, demineralized water with the addition of glycols. Preferably, the second heat transfer fluid is a diathermic oil.

[0035] The first refrigerant fluid in the first circuit 2 is therefore used for the thermal conditioning of the second refrigerant fluid in the second circuit 3. The second heat transfer fluid directly receives heat only from the second refrigerant fluid.

[0036] In particular, the heat pump module 1 is configured such that the first refrigerant fluid draws heat from the second refrigerant fluid in the second heat exchanger 6 causing the first refrigerant fluid to condense.

[0037] Preferably, the second heat exchanger 6 is configured as a condenser for the first refrigerant fluid.

[0038] Suitably, the first refrigerant fluid and the second refrigerant fluid are different from each other. “Different” here means that the first refrigerant fluid is a substance differing from the second refrigerant fluid. In other words, their chemical nature is different.

[0039] Preferably, the first refrigerant fluid is R513A, R134 or R552A. It is likewise possible to use any refrigerant fluid of the HFC and HFO type with a GWP below 1000. Alternatively, the first refrigerant fluid is subcritical CO2. Preferably, the first refrigerant fluid is R513A, whose chemical composition is a mix of 1 ,1 ,1 ,2-Tetrafluoroethane and 2,3,3,3-Tetrafluoroprop-1 -ene. This fluid offers the advantage of a condensation temperature around 70°C. Preferably, the second refrigerant fluid is R1233zd, R1234yf or R1234ze. It is likewise possible to use any refrigerant fluid of the HFO type with a GWP below 10. Alternatively, the second refrigerant fluid is butane, propane, or pentane.

[0040] Preferably, the second refrigerant fluid is R1233zd, whose chemical composition is trans-1 -Chloro-3,3,3-trifluoropropene.

[0041] Preferably, the first refrigerant fluid is R513A and the second refrigerant fluid is R1233zd. This combination is particularly advantageous in terms of heat pump efficiency and experimental tests have shown it to be the best possible combination in relation to the desired temperatures.

[0042] Below is a description of the cycle of the first refrigerant fluid. In the first heat exchanger 4 a heat exchange takes place such that the temperature of the first refrigerant fluid increases, whilst the temperature of the first heat transfer fluid decreases. In particular, the first refrigerant fluid evaporates, transforming into a gas. It then passes through the first compressor 5 in which the pressure of the first refrigerant fluid and consequently its temperature increase, exploiting the volume reduction. The first refrigerant fluid is sent into the second heat exchanger 6 in which a heat exchange takes place between the first refrigerant fluid and the second refrigerant fluid. The first refrigerant fluid transfers heat to the second refrigerant fluid, whereby the first refrigerant fluid cools and is condensed. The first refrigerant fluid then passes through the first expansion valve 7 to start its cycle over again.

[0043] Below is a description of the cycle of the second refrigerant fluid.

[0044] The second refrigerant fluid enters the second compressor 8, in which the pressure of the refrigerant fluid and consequently its temperature increase, exploiting the reduction in volume. It then passes through the third heat exchanger 9, in which a heat exchange takes place with the second heat transfer fluid. In particular, the second refrigerant fluid transfers heat to the second heat transfer fluid. Thereafter, the second refrigerant fluid passes through the second expansion valve 14, and then enters the second heat exchanger 6 in which it receives heat from the first refrigerant fluid, causing the first refrigerant fluid to condense.

[0045] It is preferred that the temperature of the first refrigerant fluid entering the second heat exchanger 6 be higher than the temperature of the second refrigerant fluid entering the second heat exchanger 6. It is also preferred that the heat exchange be sufficient to cause the first refrigerant fluid to condense. It is not possible to identify precise temperatures of the refrigerant fluids entering the second heat exchanger 6, as this will vary based on many parameters which can differ from case to case.

[0046] By way of example, the second refrigerant fluid enters the second compressor 8 at 60°C and 10 bar and exits at 125°C and 40 bar. It then passes through the third heat exchanger 9, in which it transfers heat to the second heat transfer fluid. On leaving the third heat exchanger 9, the second refrigerant fluid is at 70 °C. Finally, it enters the second heat exchanger 6, where it is heated by the first refrigerant fluid at 80 °C and 10 bar. This causes the first refrigerant fluid to cool and condense.

[0047] By way of example, the first refrigerant fluid enters the second heat exchanger 6 at 70°C, whereas it is throttled at 5 °C.

[0048] In accordance with one embodiment, the heat pump module 1 comprises an economizer 10 arranged to perform the task of lowering the temperature of the first refrigerant fluid exiting the second heat exchanger 6 before the first expansion valve 7.

[0049] Preferably, the economizer 10 comprises a first inlet 10a, located downstream of the first outlet 6b of the second heat exchanger 6, the first inlet 10a being connected to a first outlet 10b, arranged upstream of the first expansion valve 7.

[0050] Preferably, the heat pump module 1 comprises a branch 11 of the first circuit 2 that may be configured to draw at least a part of the first refrigerant fluid between the first outlet 10b of the economizer 10 and the first expansion valve 7. The branch 11 extends in such a way as to bring the first refrigerant fluid thus drawn towards the first compressor 5 passing through the economizer 10, more specifically through a second inlet 10c and a second outlet 10d of the economizer. A third expansion valve 12 is provided along the branch 11 upstream of the second inlet 10c of the economizer 10.

[0051] The first refrigerant fluid drawn in the branch 11 is used in the economizer 10 to cool the first refrigerant fluid, before it is sent to the first expansion valve 7. In other words, the economizer 10 operates through internal resources of the first circuit 2, as a mean for optimizing the performance of the first circuit 2.

[0052] Conveniently, the heat pump module 1 may comprise a liquid receiver device 13 arranged on the first circuit 2 between the second heat exchanger 6 and the first expansion valve 7. Preferably, the liquid receiver device 13 is located between the first outlet 10b of the economizer 10 and the start of branch 11 .

[0053] The heat exchangers mentioned in the present invention can be of the tube bundle or plate type or another type.

[0054] In the preferred embodiment, the first heat exchanger 4 and the third heat exchanger 9 are of the tube bundle type, while the second heat exchanger 6 is of the plate type.

[0055] As represented on figure 1 , the heat pump module 1 may comprise one, two or three capillary tube 15 associated with the expansion valves 7, 12, 14. The role of the capillary tube 15 is to send some refrigerant fluid directly to the compressor 5, 8, if the opening of the expansion valve 7, 12, 14 does not allow all the refrigerant fluid to pass through it.

[0056] The heat pump module 1 described above is capable of delivering up to 1 MW of thermal power. It is possible to connect a number of heat pump modules 1 together to increase the obtainable thermal power.

[0057] The heat pump subject-matter of the present invention can therefore be modulated. A plant 100 is the subject-matter of the present invention and will be described below.

[0058] The plant 100 comprises at least one heat pump module 1 as described above.

[0059] The plant 100 comprises a first refrigerant fluid flowing in the first circuit 2 of the heat pump 1 .

[0060] The plant 100 comprises a second refrigerant fluid flowing in the second circuit 3 of the heat pump 1 .

[0061] The plant 100 comprises a heat exchange apparatus 101 operatively associated with at least the second heat transfer fluid. This means that the second heat transfer fluid contributes directly or indirectly (i.e. by means of an interposed fluid) to the heat exchange in the apparatus 101 .

[0062] Preferably, the plant 100 comprises a first line L1 for bringing the second heat transfer fluid from the heat pump module 1 to the apparatus 101.

[0063] Preferably, the plant 100 comprises a second line L2 for drawing the first heat transfer fluid exiting the first heat exchanger 4. Preferably, the second line L2 extends in such a way as to bring the first heat transfer fluid into the apparatus 101 in order to thermoregulate the heat exchange.

[0064] For example, in the apparatus 101 a high temperature is reached to trigger a reaction, after which the temperature is regulated (in particular, a cooling takes place) for reasons of stability and manageability of the substance at the end of the process.

[0065] In accordance with one embodiment, the apparatus 101 is configured to generate steam at a low pressure (in a range comprised between 2 and 6 bar). In other words, the apparatus 101 is a steam generator. In this case, the plant 100 preferably comprises a compressor 102 such as for example a Venturi ejector downstream of the apparatus 101 for recompressing the steam, bringing it to an average pressure comprised between 6 and 10 bar. The passage into the compressor 102 entails a consequent rise in temperature up to 180°C. Figure 1 only represents the first heat transfer fluid being sent to the apparatus 101 through the line L2, but other uses of first heat transfer fluid are possible. In particular, all of the first heat transfer fluid, or a part of it, upon exiting the first heat exchanger 4, may be sent to one or several units consuming cold energy, for example a refrigeration or cooling apparatus, not operatively associated with the apparatus 101 .

[0066] Preferably, the plant 100 comprises a first buffer tank 103 for the storage of the second heat transfer fluid. The first tank 103 is preferably connected to a gas boiler or to a group of electric heating elements, should it be necessary to further increase the temperature of the hot heat transfer fluid. Preferably, the plant comprises a second buffer tank (not illustrated) for the storage of the first heat transfer fluid.

[0067] A method for heating a substance is the subject-matter of the present invention and is described below. The method is advantageously implemented by the heat pump module and by the plant as described above.

[0068] The method comprises a step of circulating a first refrigerant fluid along a first circuit 2.

[0069] During circulation in the first circuit 2, the method comprises a step of heat exchange between the first refrigerant fluid and a first heat transfer fluid. In this step, the first heat transfer fluid transfers heat to the first refrigerant fluid, which evaporates. Preferably, this step takes place in the first heat exchanger 4.

[0070] The first heat transfer fluid is often identified as a “cold source” as a refrigerant fluid with a low boiling point is used, therefore a low-temperature fluid can be used. Usually, this cold source is water, possibly added with glycol, or other fluid. Typically, the inlet temperature is between 10°C and 25°C and the outlet temperature between 5°C and 10°C.

[0071] In one embodiment, the water enters at about 12°C and exits at about 7°C. For these reasons, it is possible to refer to the first heat transfer fluid as “cold heat transfer fluid”. The method comprises a step of circulating a second refrigerant fluid along a second circuit 3.

[0072] During circulation in the second circuit 3, the method comprises a step of heat exchange between the second heat transfer fluid and a second refrigerant fluid. In this step, the second heat transfer fluid receives heat from the second refrigerant fluid. Preferably, this step takes place in the third heat exchanger 9.

[0073] The second heat transfer fluid is a fluid intended to receive heat from the second refrigerant fluid in order to carry it to a destination in which it transfers heat, directly or indirectly, to a substance.

[0074] In contrast to the first heat transfer fluid, the second heat transfer fluid is identified as a “hot heat transfer fluid”.

[0075] The method comprises a step of heat exchange between the first refrigerant fluid and the second refrigerant fluid. In this step, the second refrigerant fluid is heated by the first refrigerant fluid. This takes place after the second refrigerant fluid has transferred heat to the second heat transfer fluid. Preferably, this step takes place in the second heat exchanger 6.

[0076] The method comprises a step of heat exchange between the second heat transfer fluid and a substance. The second heat transfer fluid transfers heat to the substance. In particular, the second heat transfer fluid has already been heated by the second refrigerant fluid.

[0077] Preferably, the method comprises a step of compressing the first refrigerant fluid. This step takes place before the heat exchange between the first refrigerant fluid and the second refrigerant fluid. Preferably, this step takes place by means of the first compressor 5.

[0078] Preferably, the method comprises a step of expanding the first refrigerant fluid. This step takes place after the heat exchange between the first refrigerant fluid and the second refrigerant fluid. Preferably, this step takes place by means of the first expansion valve 7.

[0079] Preferably, the method comprises a step of compressing the second refrigerant fluid. This step takes place before the heat exchange between the second heat transfer fluid and the second refrigerant fluid.

[0080] By way of example, the second refrigerant fluid is compressed from 60°C and 10 bar up to 125°C and 40 bar. It then transfers heat to the second heat transfer fluid, going down to 70 °C. Finally, it is heated by the first refrigerant fluid at 80 °C and 10 bar. The cooling is such as to cause the first refrigerant fluid to condense.

[0081] By way of example, the first refrigerant fluid is at 70°C before the heat exchange with the second refrigerant fluid, whereas it is throttled at 5°C. Preferably, the method comprises a step of heat exchange between the first heat transfer fluid and the substance. The substance is cooled by the first heat transfer fluid.

[0082] Preferably, the first heat transfer fluid is used to thermoregulate a reaction triggered in the substance by the heat exchange with the second heat transfer fluid.

[0083] Suitably, the first refrigerant fluid and the second refrigerant fluid are different from each other. By “different” herein is meant that the first refrigerant fluid is a different substance from the second refrigerant fluid. In other words, their chemical nature is different.

[0084] Preferably, the first refrigerant fluid is R513A, R134 or R552A. It is also possible to use any refrigerant fluid of the HFC and HFO type with GWP less than 10. Alternatively, the first refrigerant fluid is subcritical CO2.

[0085] Preferably, the first refrigerant fluid is R513A.

[0086] Preferably, the second refrigerant fluid is R1233zd, R1234yf or R1234ze. It is also possible to use any refrigerant fluid of the HFO type with GWP less than 2500. Alternatively, the second refrigerant fluid is butane, propane, or pentane.

[0087] Preferably, the first refrigerant fluid is R513A and the second refrigerant fluid is R1233zd. This combination is particularly advantageous in terms of heat pump efficiency and experimental tests have shown it to be the best possible combination in relation to the desired temperatures.

[0088] Preferably, the method comprises a step of generating steam by means of a heat exchange with the second heat transfer fluid. Preferably, the generated steam is recompressed by a compressor 102 such as a Venturi ejector.

[0089] The present invention achieves important advantages.

[0090] First of all, the proposed heat pump module is capable of producing a cold heat transfer fluid and a hot heat transfer fluid. Energy consumption being equal, a heat pump with a single refrigerant fluid circuit would not be able to produce cooling.

[0091] In addition, the proposed heat pump module is able to provide a hot heat transfer fluid up to 135°C, which in the case of steam generation results in a steam that can reach up to 180°C thanks to the Venturi ejector.

[0092] In addition, the proposed heat pump module is able to function without external cold or hot sources. The cold source of the heat pump module 1 is the first heat transfer fluid. The calories drawn from the first heat transfer fluid may come from a unit consuming cold energy, for example a refrigerating or cooling means, or from the apparatus 101 , where the first heat transfer fluid may be used to thermoregulate the transfer of heat from the second heat transfer fluid to a substance. The hot source of the heat pump module 1 is the second heat transfer fluid. The calories carried by the second heat transfer fluid may be injected in a unit consuming heat, for example a heating means.

[0093] From experimental tests, it was found that the proposed heat pump module has an efficiency comprised between 4,5 and 8 (COP value, “Coefficient of Performance”).

[0094] This means that the heat pump module and the plant can be used in all contexts that require such high temperatures, such as for example the chemical industry for the activation of a reaction.

[0095] This has numerous advantages, as there are no CO2 emissions and the existing gas heating systems can be replaced.

Claims

CLAIMS1 . A heat pump module (1 ), comprising: a first circuit (2) for a first refrigerant fluid and a second circuit (3) for a second refrigerant fluid; a first heat exchanger (4) arranged on the first circuit (2) for heat exchange between the first refrigerant fluid and a first heat transfer fluid; a first compressor (5) arranged on the first circuit (2) downstream of the first heat exchanger (4); a second heat exchanger (6) interposed between the first circuit (2) and the second circuit (3) for transferring heat from the first refrigerant fluid to the second refrigerant fluid, causing said second refrigerant fluid to condense, said second heat exchanger (6) being located on the first circuit (2) downstream of the first compressor (5); a first expansion valve (7) arranged on the first circuit (2) between the second heat exchanger (6) and the first heat exchanger (4); a second compressor (8) arranged on the second circuit (3) downstream of the second heat exchanger (6); a third heat exchanger (9) arranged on the second circuit (3) downstream of the second compressor (8) for heat exchange between the second refrigerant fluid and a second heat transfer fluid; and a second expansion valve (14) arranged on the second circuit (3) between the third heat exchanger (9) and the second heat exchanger (6).

2. The heat pump module (1 ) according to claim 1 , wherein the first refrigerant fluid is R513A and the second refrigerant fluid is R1233zd.

3. The heat pump module (1 ) according to claim 1 or 2, wherein the second refrigerant fluid is brought into the third heat exchanger (9) at temperatures comprised between 80°C and 125°C.

4. The heat pump module (1 ) according to any one of the preceding claims, comprising an economizer (10) arranged on the first circuit (2), said economizer (10) being arranged so that the first refrigerant fluid, between the second heat exchanger (6) and the first heat exchanger (4), passesthrough a first inlet (10a) and a first outlet (10b) of the economizer (10), and the first circuit (2) comprises a branch (11 ) starting between the first outlet (10b) of the economizer (10) and the first heat exchanger (4), and configured to send the first refrigerant fluid to a second inlet (10c) and a second outlet (1 Od) of the economizer (10), then to the first compressor (5).

5. The heat pump module (1 ) according to claim 4, comprising a liquid receiver device (13) arranged on the first circuit (2) between the first outlet (10b) of the economizer (10) and the start of the branch (11 ).

6. A plant (100), comprising: at least one heat pump module (1 ) according to any one of the preceding claims; a heat exchange apparatus (101 ), said apparatus (101 ) being operatively associated with at least the second heat transfer fluid.

7. The plant (100) according to claim 6, wherein the apparatus (101 ) is a steam generator, said plant (100) comprising a compressor (102) downstream of the apparatus (101 ).

8. The plant (100) according to claim 6 or 7, wherein said apparatus (101 ) is also operatively associated with the first heat transfer fluid.

9. The plant (100) according to claim 8, wherein said plant is configured for the first heat transfer fluid to thermoregulate a reaction triggered by the heat exchange between a substance and the second heat transfer fluid.

10. The plant (100) according to one of the claims 6 to 9, comprising at least one unit consuming cold energy, and the plant comprises means for transferring cold energy from the first heat transfer fluid to said at least one unit.11 . A method for heating a substance, comprising the steps of: circulating a first refrigerant fluid in a first circuit (2); during the step of circulating a first refrigerant fluid, exchanging heat between the first refrigerant fluid and a first heat transfer fluid such that the first heat transfer fluid transfers heat to the first refrigerant fluid, which evaporates;circulating a second refrigerant fluid in a second circuit (3); during the step of circulating a second refrigerant fluid, exchanging heat between the second refrigerant fluid and a second heat transfer fluid such that the second heat transfer fluid receives heat from the second refrigerant fluid; exchanging heat between the first refrigerant fluid and the second refrigerant fluid such that the first refrigerant fluid transfers heat to the second refrigerant fluid and condensates, said step occurring for the second refrigerant fluid subsequent to the step of exchanging heat between the second refrigerant fluid and a second heat transfer fluid; exchanging heat between the second heat transfer fluid and a substance, said step occurring after the second heat transfer fluid has received heat from the second refrigerant fluid.

12. The method according to claim 10, wherein the step of exchanging heat between the second refrigerant fluid and a second heat transfer fluid occurs with the second refrigerant fluid at temperatures comprised between 80°C and 125°C.

13. A method for using a plant according to one of the claims 6 to 10, wherein the second heat transfer fluid is used to heat a substance through said heat exchange apparatus (101 ), and the first heat transfer fluid is used to thermoregulate said heating.

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