EP0197098A1

EP0197098A1 - Thermo-electric micro-unit

Info

Publication number: EP0197098A1
Application number: EP85904984A
Authority: EP
Inventors: Robert Charles; Jules Antoine Chapelle
Original assignee: Sarl GLASOLTHERM
Current assignee: S.A.R.L. GLASOLTHERM
Priority date: 1984-10-18
Filing date: 1985-10-11
Publication date: 1986-10-15
Also published as: FR2572169B1; WO1986002432A1; FR2572169A1

Abstract

Moteur thermique (1) équipé en énergie totale et pompe à chaleur utilisant des compresseurs électriques (2) et puisant sa chaleur à l'atmosphère (chaleur de l'air et rayonnement solaire) par des échangeurs (8). L'ensemble a la particularité de ne nécessiter aucune ressource particulière en eau (tous les circuits étant des circuits fermés). La micro-centrale produit de l'électricité pouvant être vendue et/ou utilisée pour faire fonctionner les compresseurs et de la chaleur pour le chauffage de bâtiments par l'intermédiaire des émetteurs (10) et/ou de l'eau chaude sanitaire stockée dans le ballon (11).Heat engine (1) equipped with total energy and heat pump using electric compressors (2) and drawing its heat from the atmosphere (air heat and solar radiation) by exchangers (8). The whole has the particularity of not requiring any particular water resource (all the circuits being closed circuits). The micro-power plant produces electricity which can be sold and / or used to operate the compressors and heat for heating buildings via emitters (10) and / or domestic hot water stored in the balloon (11).

Description

THERMOELECTRIC MICRO-CENTRAL I - STATE OF THE ART

There are many manufacturers of diesel heat engines or gas engines on the market. These motors can be coupled to a synchrome or asynchrome generator and mounted in total energy; that is to say that heat is recovered by cooling the engine and the exhaust gases. This produces a combined heat and power plant which is therefore an existing product. This product exists in a very wide power range; the motors being. for small powers of truck engines, for large powers of slow engines (marine type). These engines exist for practically all fuels: fuel oil, gas, biomass gas.

In addition, a technology has been developed and patented under the name of GLASOLTHERM with a number of variants:

- Patent nº 7708054, filed on 17/03/77, published under nº 2 384 214.

- Certificate of addition nº 78 30638, deposited on 10/27/78, published under nº 2 439 954.

- Patent nº 8013831, deposited on 06/20/80, published under nº 2 485 169. - Certificate of addition nº 8112149 deposited on

06/19/81, published under nº 2 508 144.

- Extension of patent nº 80 13831 to Europe: European patent nº 81 400 986.6 dated 19/06/81.

- Extension of patent nº 80 13831 in the USA: nº 43 64 239 of 12/21/82.

- Patent nº 81 08846, filed on 05/05/81, published under nº 2 505 474.

- Extension of patent nº 81 08846 to Europe: European patent nº 82 400 625.4 dated 05/05/82. - Extension of patent nº 81 08846 in the USA: nº 374 686 on 05/04/82. It is a system for producing heat from electrical energy. The. system includes a heat pump using electric compressors. Heat is drawn from the atmosphere (sensible and latent heat) and also comes from direct radiation through solar exchangers.

Thermal production takes place at three temperature levels corresponding to three cascade exchangers on the thermodynamic circuit, called: desuperheater, condenser, sub-cooler. This new system was scientifically monitored during two heating seasons.

This system, as of now, can be manufactured by various industrialists specializing in refrigeration equipment. It is also possible to adapt the same thermal production at three temperature levels to outdoor air / water heat pumps. DESCRIPTION OF THE INVENTION

The invention lies in the combination of the two techniques described above and the effects of one on the other. The assembly constitutes a thermoelectric micro-plant which has the particularity of not requiring any particular resource of water coming for example from a water table or from a river. The evaporator and engine cooling water circuits are closed circuits.

The energy necessary for the operation of the thermoelectric micro-plant is:

- thermal energy supplied by a liquid or gaseous fossil fuel up to X%,

- solar energy from the capture of solar radiation or drawn from the ambient atmosphere up to Y%,

- electrical energy supplied by the EDF centralized network up to Z%. Thus the choice of site for installing the installation is freed from a certain number of constraints. Adaptation to the climatic site of a project and the choice of sizing of the different elements of the micro-power plant defining the terms X, Y and Z. The advantage of combining the two elements is twofold. . By reference to the heat engine alone, mounted in total energy, the association with GLASOLTHERM makes it possible to save primary energy.

This can be illustrated by the application to a particular case: heating of 200 homes.

In this case, the fuel consumption due to heating is 395.6 m ³ of fuel per year, or 334 toe. The micro-central solution makes it possible to satisfy these needs by consuming 3,237,500 kWh of gas, or 279 toe and 319,500 kWh of electricity, or 79 toe; in addition, the system produces 838,200 kWh of electricity, the production of which would have required the consumption of 210 toe by other means. The complete balance sheet is detailed on the following diagram attached.

In summary :

- the reference solution leads to a consumption of 334 + 210 = 544 toe.

- the microcentral solution: _ 279 + 70 = 349 toe.

Primary energy savings: 544 - 349 = 195 toe. Coefficient of performance in primary energy: 544

COP = = 1.56 349

This coefficient of performance is high thanks to the use of solar energy in the system. With reference to the GLASOLTHERM system alone, the association with a heat engine mounted in total energy makes it possible to significantly reduce the power of the GLASOLTHERM machine.

By way of example, using the case cited above, we arrive at a design of 450 kW thermal for the nominal thermal needs of 1,514 kW. The complement is provided by heat recovery from heat engines. In each case, the respective parts of the engine and of GLASOLTHERM in determining the total power must be determined in order to obtain the economic optimum. Indeed, the interest of reducing the power of GLASOLTHERM is economical.

The profitability of GLASOLTHERM depends directly on its number of hours of use at maximum power (the investment being almost proportional to the power). GLASOLTHERM alone for heating residential premises operates at around 2,200 hours / year at maximum power. GLASOLTHERM undue in a thermoelectric microcentral works at 3,500 h / year in the case mentioned above. Generally speaking, this annual number of hours of operation at maximum power is between 3,000 and 5,000 h / year.

This micro-power plant produces:

- electricity that can be sold or used to operate electric refrigeration compressors,

- heat by recoveries on engines and exhaust gases and at the various heat exchangers located on the refrigeration circuit. An example of an association thus producing a thermoelectric micro-plant is described in diagram 1. The proposed installation comprises eight hydraulic circuits: a) The circuit (1) for heat recovery from the exhaust gases: transfers the heat taken from the smoke / water exchanger (E4) at the two water / water exchangers connected in series (E1) for heating the heating floor circuit (7) and (E5) for heating the DHW production circuit (domestic hot water) (5). b) The circuit (2) constitutes the cold loop: it ensures the transfer of the calories taken from the aerosol exchangers (ES) to the evaporator (EV), with the possibility of additional heating for very low temperatures thanks to the 'exchanger (E2) on the cooling of engines G1, G2, G3, G4. This loop is regulated by the modulating three-way valve (W1) which guarantees a minimum temperature at the inlet of the evaporator (EV) (around - 7º C).

The heat transfer fluid is for example a solution of mono-ethylene glycol. c) The circuit (3) is the cooling circuit of the

4 motors G1, G2, G3, G4: mounted in parallel; it allows the flow of heat thanks to the two exchangers (E3) on the heating circuit of the heated floors (7), and (E2) if necessary on the circuit of the aerosol exchangers (ES). d) The circuit (4) constitutes the sanitary water loop.

The water in the three tanks (B1), (B2), (B3) mounted in parallel on this circuit is heated by direct passage through the exchanger (E6). The solenoid valves at the inlet of each tank allow you to heat only the tanks that need it. e) The DHW heating circuit (5) transfers in (E6) the calories taken off either in (E5) or on the condenser of the heat pumps (CO). f) The circuit (6) provides terminal heating of the tank (B4) from the heat flow of the desuperheater (DE) of the heat pumps. g) The heating floor heating circuit (7) allows the return of the floors to warm up by passing successively through the condensers (CO) (if applicable), then the exchangers (E1) and (E3). h) The domestic water distribution circuit (8) includes the 4 tanks (B1), (B2), (B3), (B4) connected in series and the DHW loop supplied with mains water by EDV. Of particular note:

1º) The possible use of the recovery heat on the engines and the exhaust gases to raise the temperature level of entry to the evaporator of the heat pump thanks to an exchanger named E2. 2º) The use of the same exchanger E2 to evacuate the heat of recovery in safety (the heat pump being stopped). It is therefore possible to use, by this means, the external solar exchangers as an air cooler. This therefore avoids the additional investment of a large power air cooler. 3º) The parallel mounting of the different motor-alternators. 4º) The production of heat at two temperature levels for domestic hot water during the operation of the heat pump (tanks B1, B2, Ε3 heated by the condenser CO and B4 heated by the desuperheater DE). This arrangement for producing domestic hot water can be further improved as shown in diagram 2 where three temperature levels are used, thanks to three exchangers: DE desuperheater, CO condenser, and SR sub-cooler.

The operation of these three exchangers is explained from diagram 3 which gives, by way of example, the enthalpy diagram of the Freon 22 and on which is depicted the operating cycle of the thermodynamic loop.

- FE corresponds to the evaporation in the evaporator,

- ED for gas compression by compressors, - DC for gas superheating,

- CB to gas condensation,

- BA at the sub-cooling of liquid Freon after condensation,

- AF for the expansion of liquid Freon from 20 bars to 3.1 bars, before introduction into the evaporator.

The three exchangers mentioned above correspond to DC, CB and BA. As physically it is difficult to separate the desuperheating phase from the condensation phase, the desuperheater (CD part) can operate partially in condenser during the transient operating conditions of the whole system, or even fully in condenser if the circulator of the loop discharging the thermal energy of condensation in the condenser (part CB) is stopped voluntarily according to the needs to satisfied. In this case, the condenser turns into a liquid reserve bottle. To achieve correct operation, it is necessary that the condenser-desuperheater is arranged above the condeirs-eizr to allow the evacuation by gravity of the condensates.

It should be noted that the heat of condensation is not transmitted directly from CO to B2 but that it is necessary to provide an intermediate exchanger EC correctly dimensioned.

The sub-cooler (part BA) cools the liquid Freon at the outlet of the condenser from 50ºC to 4ºC in the example given by diagram 3 before expansion. During the transient operating conditions of the system which are the rule due to the climatic variations to which the solar exchangers are subjected, it is imperative, so that the sub-cooler does not transform into a condenser, to separate at the outlet of the condenser the phases gaseous and liquid Freon by placing a reserve bottle of liquid of sufficient volume to take account of rapid variations in Freon flow during transient phenomena. To check the correct functioning of the liquid reserve bottle, a liquid sight glass is placed at the outlet of this one.

This exploitation of the thermodynamic cycle in diagram 2 allows successively the preheating, heating and terminal heating of hot water with the following advantages:

- the suitably sized de-superheater can be used as a condenser if necessary, giving the system great flexibility of use to meet demand during drawing (priority to such and such a balloon). - this solution makes much better use of the thermodynamic cycle by not degrading the temperature level (no mixing in a single heat exchanger of condensation and desuperheating heat). The sub-cooling of the hot liquid at the outlet of the condenser and before expansion, results in a significant improvement in the coefficient of performance (COP) and therefore in a greater use of renewable energy: atmospheric and / or solar. - This solution leads to lower compression rates than if one sought to obtain water at the same temperature level with a single condenser. This naturally affects the life of the compressors. We will note in the assembly described on diagram nº 2 the importance of xamener the returns of loop of the DHW on the tank (B2) heated by the condenser (CO). The desuperheating and subcooling powers are indeed insufficient to combat loop losses.

It should be noted that the use of the three exchangers of the thermodynamic circuit can find other outlets. Let us cite as an example the production of hot air thanks to the sub-cooler, of heating water thanks to the condenser, of domestic hot water thanks to the superheater.

The hot water tanks can also be produced in accordance with the diagram attached nº 4 in which it will be noted that the heat exchanger (EC) of diagram nº 2 is replaced by internal cylinders in the hot water tanks B1, B2 and B3 . These three tanks ensure the role of exchangers by their surface and that of the anti-short-cycle buffer by their volume. These points will be developed in 6º). 5º) The fact that the use of solar heat exchangers (ES) in the heat pump's heat source makes it possible to get rid of a local water resource (groundwater, river, lake ...). The whole system works with closed circuits. 6º) The use of a tank of the type described on diagram nº 4 for the production of domestic hot water. This balloon is made up of different capacities included in each other. The external capacity marked (A) contains domestic hot water. It is heated thanks to the internal tanks B1, B2, B3. These three tanks act as exchangers due to their surface; they therefore replace the exchanger provided in diagram 1, which eliminates the need for a circulator. On the other hand, the exchange being done in stat iqùe (the velocities of the fluids, even during a drawing are very low), it is necessary to dimension the surfaces consequently. In addition to their exchange function, the three capacities

B1, B2, B3, play the role of anti shortcyle buffer. When the system delivers a power higher than that which can be evacuated instantaneously towards domestic hot water, the mass of the tanks B1, B2, B3 heats up avoiding trips of the high pressure safety devices of the compressors. The third capacity included in the others, marked C, exists only in systems with separate ice storage (see variant 2) and serves as a reserve for de-icing the evaporator. It is filled with an antifreeze mixture and heated by its surface. Variants

In addition to the above, it is possible to envisage a number of variants in the overall scheme: Variant 1 Use of an outdoor air / water heat pump instead of the water / water pump shown in diagram 1.

In this case, in fact, we always value electricity by a performance coefficient. In addition, with this equipment, it is still not necessary to have a water resource. If such a variant is used, it should be noted that the same mode of use of the thermodynamic cycle can be kept with three exchangers. Furthermore, the engine-heat pump coupling makes it possible to use the two thermal resources according to the possibilities: when the air / water heat pump is unusable because of too low outside temperatures, recovery can be used on the engines.

It is also possible to provide for the joint operation of motor-generators and heat pumps at low outdoor temperature by using heat recovery units on diesel groups as preheating of the outdoor air according to diagram 5.

It is obvious that in this case it is no longer possible to do without an emergency dry cooler. Option 2 Use of GLASOLTHERM ice storage

The GLASOLTHERM system is capable of operating in very low outside temperatures while maintaining a performance coefficient greater than 2.5. This is achieved through ice storage. The latent heat of transformation of ice water into cold source of the heat pump is used. In diagram 1 presented by way of example, this storage does not exist, it is replaced by an additional heat exchanger in cold source E2 taking its heat from the circuit for recovering heat engines. That said, it is possible to foresee this storage in the diagram and that in two different ways:. Dissociated ice storage

The use of this storage in the GLASOLTHERM system is shown in diagram No. 6. The ice is formed on the evaporator (1) and removed by de-icing. This de-icing uses either hot water produced by the machine itself and stored, for example in reserve C of a tank of the type described in diagram 4 marked (9), or solar energy when it is in excess of needs.

. Integrated ice storage

The use of this storage in GLASOLTHERM is shown in diagram 7.

The ice forms directly inside the storage volume (7) on submerged plates (9) mounted in a Tickelman loop in which the unfrozen fluid of the aerosol exchanger loop circulates.

The design of the plates arranged vertically and connected by fins welded to the ends is such (see diagram nº 8) that it is possible to carry out icebreaking using excess solar energy. The ice is then peeled off the surface of the submerged plates and rises to the surface of the stock.

In both storage modes, back-up from city water is possible to melt the ice in the same year.

The introduction of ice storage into the general scheme of the invention which is the subject of this patent makes it possible to envisage certain new possibilities. Variant 2.1. In the case of integrated ice storage, the water reserve can be used to store surpluses of heat produced by the heat engine. This storage will allow the heat pump to operate with better performance. The storage mode for the excess calories can be done by reusing the exchanger E2 of diagram nº 1 according to the "variant" assembly of diagram nº 9. The valve VI being open in α and the heat pump stopped, the circuit heat recovery (3) from groups G1, G2, G3, G4 transfers calories via E2 using the submerged exchanger E7. The 3-way valve

V1 is closed at α and open at β.

An example of a micro power plant with integrated ice storage is given in Figure 10. Variant 2.2. In the case of dissociated ice storage, the transfer of calories from the recovery circuit (3) to storage takes place thanks to the evaporator exchanger EV operating in series with the exchanger E2 in diagram 1 thus constituting a figured "variant" diagram. in diagram No. 11. With the heat pump stopped and the valve V1 open, the anti-freeze fluid circulates from the exchanger E2 to the evaporator exchanger (EV). An example of a microcentre with dissociated ice storage is given in diagram 12.

Variant 3

Introduction of hot stock

In the basic diagram which we are discussing, there is no provision for hot stock insofar as the heat is intended for the heating of buildings equipped with heated floors. In this particular case, the storage of excess calories can be carried out in the slab directly by taking advantage of the high inertia of the concrete. In the case where it is a question of radiators, it could be necessary to envisage a hot stock which would be added on diagram nº 1 according to the variant figured on diagram nº 13. This stock can be with sensible heat or with latent heat. LEGEND

DIAGRAM OF THE THERMOELECTRIC MICROCENTRAL n ° 1 0

1. Generator set

2. 2 hermetic compressors

3. Desuperheater condenser

4. Condenser

5. Exchanger-evaporator

7. Storage bin

8. Solar exchangers

9. Circulation pump for solar exchangers

10. Heat emitters

11. DHW heat exchangers

12. Check valve

13. Plate heat exchanger

14. Heat emitting circulation pump

15. DHW circulation pump

16. 3-way mixing valve

17. 3-way thermal charging valve

18. Liquid reserve bottle

19. Subcooler

20. Renewal air duct of the room to be heated

21. Terminal heating coil

22. Fresh air blower

23. Generator refrigeration circuit pump LEGEND

THERMOELECTRIC MICROCENTRAL DIAGRAM n ° 12

1. Generator set

2. 2 hermetic compressors

3. Desuperheater condenser

4. Condenser

5. Exchanger-evaporator

6. Thermal charging pump

7. Storage bin

8. Solar exchangers

9. Circulation pump for solar exchangers 10. Heat emitters

11 .. DHW heat exchangers

12. Check valve

13. Plate heat exchanger

14. Heat emitting circulation pump

15. DHW circulation pump

16. 3-way mixing valve

18. Liquid reserve bottle 19. Subcooler

20. Renewal air duct of the room to be heated

21. Terminal heating bacteria

22. Renewal air blower

23. Generator group refrigeration circuit pump LEGEND

DIAGRAM OF THE THERMOELECTRIC MICROCENTRAL OF THE DESCRIPTIVE ABBREVIATION

1. Generator set

2. 2 hermetic compressors

3. Desuperheater condenser

4. Condenser

5. Exchanger-evaporator

7. Storage bin

8. Solar exchangers

9. Circulation pump for solar exchangers 10. Heat emitters

11. DHW heat exchangers

12. Check valve

13. Plate heat exchanger

14. Heat emitting circulation pump

15. DHW circulation pump

16. 3-way mixing valve

17. 3-way thermal discharge valve

18. Liquid reserve bottle

19. Subcooler

20. Renewal air duct of the room to be heated

21. Terminal heating coil

22. Fresh air blower

23. Generator refrigeration circuit pump

Claims

II - CLAIMS

1. Heat / force production system characterized in that the force production is ensured by heat engines equipped with total energy consuming liquid or gaseous, fossil or biomass fuels, in that the additional heat production has recovery from heat engines is carried out by a heat pump system using solar and / or atmospheric energy, and in that it does not require any water resource from, for example, a water table or a river , all the circuits (including those for cooling the heat engine and the evaporator) being closed circuits and leading to primary energy savings

(coefficient of performance at least equal to 1.3). The economic optimum is obtained by fixing the respective powers of the heat engines and the heat pump as well as possible.

2. System according to claim 1, characterized in that the recovery heat on the internal combustion engines can be used to heat the fluid entering the evaporator, whether it be air or an intermediate fluid.

3. System according to claim 2, characterized in that the system for capturing atmospheric and / or solar energy can serve as a system for safely removing calories from the heat recovery system on heat engines.

4. System according to claim 1, characterized in that part of the heat can be used for the production of domestic hot water using for this three temperature levels corresponding to three distinct parts of the refrigeration cycle.

5. System according to claim 1, characterized in that the excess heat produced by the heat engine recovery circuit can be stored in a water store located on the cold source circuit of the heat pump.

6. System according to claim 1, characterized in that the excess heat from the recovery circuit on the internal combustion engines can be stored in a hot store (sensible or latent heat) located on the heat distribution circuit.

7. Domestic hot water tank according to claim 4, characterized in that the production loop of E.C.S. comprises in the storage tank a storage exchanger having a sufficient volume to avoid short-cycles of the heat pump, and produced for example by stacking hemispherical bottoms assembled two by two by welding.

8. Hot de-icing fluid reserve according to claim 4 disposed inside the production loop of E.C.S.

9. Plate exchanger according to claims 1 and 5, placed in a cold water store and such that it can successively form ice on its plates, then peel it off by circulation of a de-icing fluid in exchanger, the ice then rising to the surface of the cold water stock.