FR2856470A1 - Heat pump installation for thermodynamic machine, has exchanger ensuring heat uptake to and exhaust of reagents using lower and upper exchangers respectively, where heat exchanges are produced by boiling/condensation of liquid/gas - Google Patents

Abstract

The installation has a unique reagent exchanger alternatively ensuring heat uptake to a reagent (S1) with the help of a lower exchanger (11) and heat exhaust of reagent (S2) by an upper exchanger (13). The heat exchanges are produced by boiling/condensation of a liquid/gas. A reactor (2) has the two reagents separated by a porous and insulating partition (12), where the reagents have exchangers.

Description

I

  The present invention relates to a solid / gas sorption heat pump comprising a single exchanger per reagent ensuring alternately the supply of heat thanks to a lower exchanger and the rejection of the reaction heat thanks to an upper exchanger, the heat exchanges being produced by boiling / condensation of a liquid / gas.

  Solid gas chemical heat pump installations are known comprising two exchangers per reactor, in particular those originating from the French patents of Jacques Bernier N 9109498, 9109499, 9208618, 9209026 and their international extensions.

  Such installations use a phase change device for heat transfers but is not entirely satisfactory because they lead to a complication of the reactor and to a reduction in the yield of the chemical reaction.

  Chemical reactors are also known comprising a single exchanger for ensuring the thermal transfers of the reactant, but the installations use a thermal transfer with a fluid without change of state which poses on the one hand the serious problem of the mass of the exchanger and its fluid leading to a loss of heating energy, but also to the non-possibility of self-regulation of the device by the principle of the thermal diode which technically greatly complicates the system.

  It is a first object of the invention to provide a solid / gas heat pump system which does not have the drawbacks of known installations.

  It is another object of the invention to provide a heat exchange device with a thermal diode comprising three transfer exchangers situated at different heights, the exchanger situated at mid-height being placed at the heart of the reagent, the exchanger of heat input at the bottom and the heat rejection exchanger at the top.

  It is always an object of the invention to provide a heat exchange device with three exchangers, the heat transfer fluid of which is a liquid / gas phase change fluid which may also contain several components which may or may not be miscible.

  The invention will be better understood from the description of the drawings given by way of example and in which: FIG. 1 is an installation according to the invention represented in cycle, production of cold and also providing heating and production of hot water.

  - Figure 2 is an installation identical to that of Figure 1 shown in regeneration cycle.

  - Figure 3 is a variant of Figure 1 ensuring the production of cold and domestic hot water, shown in the cold production cycle.

  - Figure 4 is identical to Figure 3 shown in regeneration cycle.

  - Figure 5 is a variant of Figure 1 ensuring only the production of cold, shown in the cold production cycle.

  - Figure 6 is identical to Figure 5 shown in regeneration cycle.

  An installation according to the invention in FIG. 1 comprises a chemical reactor (2) comprising a reagent (S1) consisting of a salt such as manganese chloride for example, linked with a thermal conductive swelling agent. The various heat transfers taking place within this reagent are provided by an exchanger (11). The reactor (2) comprises a porous barrier (12) allowing the diffusion of a gas such as ammonia. The second part of the reactor (2) contains a reagent (S2) which can either be liquid NH3 or a salt such as barium chloride, for example linked with a thermal conductive swelling agent. The reagent (S2) contains an exchanger (13) which provides the various heat transfers.

  FIG. 1 is represented in the cold production phase which is provided by an evaporator (3) in which a secondary air or water fluid circulates, for example, pulsed by a pump (8) towards a circuit for using the cold (F) .

  Note that (8) can be a fan in the event of cold air diffusion.

  Refrigerant, such as HFC R-134a descends by gravity from the exchanger (13) through the piping (24) to the exchanger (19) producing cold. The liquid will vaporize in the exchanger (19) at a temperature of the order of 0 C thus ensuring the production of cold, the vapor of R-134a formed rises through the piping (23) towards the exchanger (13) o it will condense to form a new cycle. In parallel, the reagent (S2) will degas from its NH3. The NH3 gas formed in the reactor will be directed to the reagent (SI) with which it reacts chemically by sorption. This last exothermic reaction will evaporate the liquid contained in the exchanger (11). The steam formed will flow through the piping (25) to the exchanger (18) of the heating condenser (4) and to the exchanger (15) of the condenser placed in the domestic hot water tank (5). The distribution valve (9) connects the piping (26) and the bottom of the exchanger (11). In this phase the refrigerant gas contained in the exchanger circuit (11,15,18) condenses in the last two, the liquid formed returning by gravity in the evaporator (11) to form a new cycle.

  Note that the transfer fluid can be for example an immiscible mixture of water and R-134a, the water being blocked in the exchanger (21) in the form of vapor and also at the inlet of the exchanger (11) in the lower part, but there in liquid form.

  In the cold production cycle of Figure 1, the gas burner (20) is placed in the boiler (1) and provides only the additional heating that may be necessary for the heating circuit (C) or the heating circuit. hot water production using the tank (5).

  To do this, two independent circulators (6) and (7) installed with a check valve 10 respectively (27) and (28) ensure, as required, the circulation of water between the exchanger (22) of the boiler (1) and respectively the heating circuit (C) and the exchanger (14) of the hot water tank (5).

  Closing the circuit of the valve (9) on the exchanger side (21) leads to the inactivation of this exchanger (21).

  During the passage of NH3 gas from the reagent (S2) to the reagent (SI), the gas passes through a porous wall (12) made of a material also thermal insulator such as glass wool or rock wool; the insulating nature of the wall (12) makes it possible to avoid direct heat transfers between the reactants (SI) and (S2).

  Figure 2 is an installation according to the invention identical to Figure 1 but shown in the reagent regeneration cycle (SI). Only the position of the valve (9) has changed, it then puts only the exchangers (21) and (11) into contact. The exchanger (21) is a boiler included in the boiler (1), under the effect of the heat released by combustion on the burner (20) the water contained in the exchanger (21) vaporizes at a temperature of 180 approximately, the vapor formed rises by the piping (34) 25 towards the exchanger (11) where it condenses while bringing heat to the reagent (SI).

  The liquid formed in (11) returns by gravity to the exchanger (21) to form a new cycle passing through the valve (9) and the piping (33).

  In parallel, the position of the valve (9) leads to a blockage of the exchanger (18) in R-134a and liquid water, thus stopping the heat exchanges of the exchanger (18).

  The addition of heat to the reagent (SI) will make it possible to release the NH3 which had bonded chemically to the reagent during the cold production phase. The NH3 gas passes through the insulating wall (12) to go towards the reagent (S2) and the exchanger (13).

  The gas will bond chemically with the salt of the reagent (S2) or simply condense on the exchanger (13) in the case of a reactor (2) with a single salt.

  In both cases the reaction is exothermic and the exchanger (13) will have to evacuate heat at a temperature of the order of 40 C. Inside the exchanger (13) will therefore vaporize the fluid R -134a, the vapor formed will go through the piping (31) to the exchangers (16) and (17) or the latter will condense by giving up its heat to the heating circuit (C) or to the water contained in the tank (5).

  The liquid formed returns through the piping (32) to the bottom of the exchanger (13) to reform a new vaporization / condensation cycle by thermosiphon with phase change.

  In the regeneration phase, there is no production of cold at the circuit (F). The exchanger (19) is clogged with liquid R-134a because it is in the lower part and at a temperature lower than that of the exchanger (13).

  It is important to note that the regeneration and cold production phases will constitute a cycle with an overall duration of the order of 10 minutes. The exchanger (19) may be associated with cold storage in the form of ice or in sensible heat, in order to have at (F) continuous production of cold. At the exchanger (4) or the tank (5), the production of heat is continuous and independent of the operating phase of the reactor.

  The recovery of thermal energy may include a condensing system at the level of the boiler (1).

  In the heat pump application, the production of cold will be evacuated to the outside to a closed circuit of a buried sensor, for example, or of an air exchanger on which outside air or extracted air will circulate.

  In heat pump application, the coefficient of performance of the device will be between 1.5 and 2, which will cut energy consumption by two compared to a boiler.

  FIG. 3 represents the invention applied without the heating function therefore intended to ensure the production of cold and domestic hot water. In Figure 3 the cycle shown is the cold production cycle. An external exchanger (42) fitted with a fan will reject the reaction heat from the appliance to the outside, which will not have found use for ensuring the production of domestic hot water thanks to the exchanger (15).

  The exchanger (42) is in heat exchange relation with the condenser (4) thanks to a circulation of water pulsed by the pump (41). In another version the ventilated exchanger (42) will be directly the condenser (4) and therefore will not require an intermediate water circuit.

  The heat of reaction of (SI) vaporizes the refrigerant contained in the exchanger (11), the steam rises to condense in the exchanger (15) ensuring the production of domestic hot water, then to the exchanger (18) which will end the condensation. The liquid will flow through the piping (45), towards the valve (40), which is in the open position in this phase. The liquid returns to the exchanger (11) of the reagent (SI) to form a new cycle.

  In this cold production phase, the reagent (SI) reacts with the ammonia coming from (S2) which is released thanks to the supply of heat at a temperature of 0 brought by the production of cold. The operation of the exchanger (19) and the exchanger (13) is similar to what has been described for FIG. 1.

  In the cold production phase, the boiler (1) does not need to operate, the exchanger circuit (21) becomes waterlogged due to the shutdown of the burner (20).

  Figure 4 is completely identical to Figure 3 except that the valve (40) is in the closed position and the burner (20) is in service to allow the regeneration of the reagent (SI). The burner boils the water contained in the exchanger (21) and directs the steam to the exchanger (11) where it condenses and then returns to the boiler through the piping (53).

  In this regeneration phase of Figure 4, the NH3 gas is fixed on (S2) which causes the temperature rise of (S2) from 0 to 40 C and boils the R-134a contained in the exchanger ( 13). The exchanger (19) is engorged in liquid R-134a stopping any heat exchange in the exchanger (19). On the other hand, the heat released by (S2) causes the vapor of R-134a to rise towards the exchanger (16) of the hot water tank (5) where it condenses and then returns via the piping (50) to the auxiliary condenser ( 4) o the gas ends its condensation in the exchanger (17) the liquid formed gravitatively returns to the bottom of the exchanger (13) via the piping (51).

  FIG. 5 represents an apparatus according to the invention ensuring only the production of cold represented in the phase of production of cold.

  The exchanger (11) being in exothermic phase rejects heat leading to a heat transfer by thermosyphon with phase change between the exchangers (11) and (74).

  The exchanger (74) is placed in the condenser (70) shown in ventilated air but which may also be in water and coupled either to buried sensors or to an air cooler as described previously in FIGS. 3 and 4.

  The operation of the system in the cold production phase is similar to that described above, the valve (40) is in the open position and the evaporator (3) produces the cold (F).

  FIG. 6 represents the same apparatus for producing cold but in the regeneration phase of the reactor (S1). The valve (40) is in the closed position and the burner (20) is in service ensuring the transfer of heat to the exchanger (11) of the reagent (Sl).

  The NH3 gas passes from (Sl) to (S2) creating a production of heat which will have to be evacuated towards the condenser (70) via the exchanger (73).

  The main application of the invention is of course heat pumps and gas air conditioners but it is not limited to this both with regard to the cold source which may be a refrigerator, a cold room or other, that with regard to the boiler providing energy which may also be solar or wood or other.

  The process according to the invention can be made continuous by the use of two reactors identical to the reactor (2) with all the accessories, one being in the regeneration phase while the other is in the cold production phase and vice versa. The system is also applicable to four-salt systems.

  The fluid reacting with the reagents (S1) and (S2) may be ammonia, water, ethanol or any other fluid capable of reacting chemically with the reagents used.

  The reagents used may be different salts such as chlorides or activated carbon or zeolite or the like.

  In general, the invention applies to any type of thermodynamic sorption machine.

Claims (9)

  1.Sorption solid / gas heat pump comprising a single exchanger per reagent 5 alternately ensuring the supply of heat to the reagent thanks to a lower exchanger and the rejection of the heat of reaction thanks to an upper exchanger, the heat exchanges being produced by boiling condensation of a liquid / gas.   2.1 installation according to claim 1 characterized in that the reactor (2) comprises two reagents (SI) and (S2) separated by a porous and insulating wall (12), each reagent comprising its single exchanger (11) and (13) .   3.1 installation according to claim 1 characterized in that the thermal circuit of the reactant (SI) comprises at least one heating exchanger (18, 15) placed (s) above the exchanger (11) and a heat input exchanger (21) placed below, the passage from one cycle to another being ensured by a three-way valve (9) 15 or two ways (40).   4.1nstallation according to claim 3 characterized in that the biphasic transfer fluid is a mixture of two immiscible liquids.   5.1 installation according to claim 1 characterized in that the thermal circuit of the reagent (S2) comprises at least one heating exchanger (17, 16) placed (s) above the exchanger (13) and an evaporator (19) placed below.   6. Installation according to claim 1 characterized in that the excess heat is discharged to the outside by an air or water condenser (4.70).   7.1nstallation according to claim 1 characterized in that the heat rejection exchangers (16,17) or (18,15) are placed in parallel or in series.   8. Installation according to claim 1 characterized in that the cooling circuit (F) is connected to a buried sensor.   9.1nstallation according to claim 1 characterized in that the active fluid of the reactants (SI) and (S2) is ammonia, ethanol or water.