HIGH TEMPERATURE THERMAL ENERGY EXCHANGE SYSTEM WITH HORIZONTAL HEAT EXCHANGE CHAMBER AND METHOD FOR EXCHANGING THERMAL ENERGY BY USING THE HIGH TEMPERATURE THERMAL ENERGY EXCHANGE SYSTEM

Abstract

High temperature thermal energy exchange system with horizontal heat exchange chamber and method for exchanging thermal energy by using the high temperature thermal energy exchange system

A high temperature thermal energy exchange (heat) exchange system is provided. The high temperature thermal energy exchange system comprises at least one horizontal heat exchange chamber with chamber boundaries which surround at least one heat exchange chamber interior of the heat exchange chamber, wherein the chamber boundaries comprise at least one inlet opening for guiding in an inflow of at least one heat transfer fluid into the heat exchange chamber interior and at least one outlet opening for guiding out an outflow of the heat transfer fluid out of the heat exchange chamber interior, at least one heat storage material is arranged in the heat exchange chamber interior such that a heat exchange flow of the heat transfer fluid through the heat exchange chamber interior causes a heat exchange between the heat storage material and the heat transfer fluid and the heat high temperature thermal energy exchange system is developed such that horizontal heat exchange flows of the heat transfer fluid through the heat exchange chamber interior differ from each other in vertical direction. The horizontal heat exchange flows are different in vertical direction of the heat exchange chamber. The heat transfer fluid is led into heat exchange channels via the inlet openings and is led out of the heat exchange channels via the outlet openings. Preferably, the heat transfer fluid is air with ambient pressure. An operating temperature of the high temperature thermal energy exchange system is more than 600° C.

Claims

1. A High temperature thermal energy exchange system with at least one horizontal heat exchange chamber with chamber boundaries which surround at least one heat exchange chamber interior of the heat exchange chamber, wherein the chamber boundaries comprise at least one inlet opening for guiding in an inflow of at least one heat transfer fluid into the heat exchange chamber interior and at least one outlet opening for guiding out an outflow of the heat transfer fluid out of the heat exchange chamber interior; at least one heat storage material is arranged in the heat exchange chamber interior such that a heat exchange flow of the heat transfer fluid through the heat exchange chamber interior causes a heat exchange between the heat storage material and the heat transfer fluid and the high temperature thermal energy exchange system is developed such that horizontal heat exchange flows of the heat transfer fluid through the heat exchange chamber interior differ from each other in vertical direction.

2. The high temperature thermal energy exchange system according to claim 1, wherein a mass ratio of the horizontal flows of the heat transfer fluid is higher than 50%.

3. The high temperature thermal energy exchange system according to claim 1, wherein the heat storage material comprises at least one chemically and/or physically stable material.

4. The high temperature thermal energy exchange system according to claim 1, wherein the heat storage material comprises sand and/or stones.

5. The high temperature thermal energy exchange system according to claim 1, wherein heat exchange channels are embedded in the heat storage material for guiding of the heat exchange flow through the heat exchange chamber interior.

6. the high temperature thermal energy exchange system according to claim 1, wherein the high temperature thermal energy exchange system is equipped with at least one flow adjusting element for adjusting the heat exchange flow of the heat transfer fluid through the heat exchange chamber interior, the inflow of the heat transfer fluid into the heat exchange chamber interior and/or the outflow of the heat transfer fluid out of the heat exchange chamber interior.

7. The high temperature thermal energy exchange system according to claim 6, wherein the flow adjusting element comprises at least one active fluid motion device which is selected from the group consisting of blower, fan and pump, and/or the flow adjusting element comprises at least on passive fluid control device which is selected from the group consisting of activatable bypass pipe, nozzle, flap and valve.

8. the high temperature thermal energy exchange system according to claim 1, wherein at least two inlet openings are arranged vertically to each other and/or at least two outlet openings are arranged vertically to each other.

9. The high temperature thermal energy exchange system according to claim 1, wherein the chamber boundary with one of the openings comprises a transition area with a tapering profile such that an opening diameter of the opening aligns to a first tapering profile diameter of the tapering profile and a chamber diameter of the heat exchange chamber aligns to a second tapering profile diameter of the tapering profile.

10. The high temperature thermal energy exchange system according to claim 1, wherein the heat transfer fluid comprises a gas at ambient gas pressure.

11. The high temperature thermal energy exchange system according to claim 10, wherein the gas at the ambient pressure is air.

12. The high temperature thermal energy exchange system according claim 1, which is equipped with at least one charging unit for heating the heat transfer fluid.

13. The high temperature thermal energy exchange system according to claim 12, wherein the charging unit comprises at least one electrical heating device which is selected from the group consisting of resistance heater, inductive heater, emitter of electromagnetic radiation and heat pump.

14. The high temperature thermal energy exchange system according claim 1, wherein the high temperature thermal energy exchange system is equipped with at least one discharging unit for discharging the heat transfer fluid of the outflow from heat for production of electricity.

15. The high temperature thermal energy exchange system according to claim 1, which is equipped with at least one measuring device for determining a charge status of the high temperature thermal energy exchange system.

16. The high temperature thermal energy exchange system according claim 1, wherein a closed loop is implemented and wherein the inflow comprises the outflow.

17. A method for exchanging thermal energy by using the high temperature thermal energy exchange system according to claim 1, wherein in an operating mode of the high temperature thermal energy exchange system a heat exchange flow of heat transfer fluid is guided through the heat exchange chamber interior, whereby a heat exchange between the heat storage material and the heat transfer fluid is caused.

18. The method according to claim 17, wherein the operating mode is selected from the group consisting of charging mode with a heat transfer from the heat transfer fluid to the heat storage material and a discharging mode with a heat transfer from the heat storage material to the heat transfer fluid.

19. The method according to claim 18, wherein in the charging mode a lower heat transfer flow is larger than the upper heat transfer flow.

20. The method according to claim 18, wherein in the discharging mode an upper heat transfer flow is larger than the lower heat transfer flow.

21. The method according to claim 17, wherein during the charging mode the heat exchange flow is directed in a charging mode direction; during the discharging mode the heat exchange flow is directed in a discharging mode direction; and the charging mode direction and the discharging mode direction are opposite direction to each other.

22. the method according to claim 17, wherein an operating temperature of the operating mode is selected from the range between 300° C. and 1000° C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Some of the embodiments will be described in detail, with reference to the following figure, wherein like designations denote like members, wherein:

[0080] FIG. 1 shows different high temperature thermal energy exchange systems;

[0081] FIG. 2 shows different high temperature thermal energy exchange systems;

[0082] FIG. 3 shows different high temperature thermal energy exchange systems;

[0083] FIG. 4A shows a high temperature thermal energy exchange systems with different thermal insulations of the heat exchange chamber;

[0084] FIG. 4B aa shows high temperature thermal energy exchange systems with different thermal insulations of the heat exchange chamber;

[0085] FIG. 4C shows high temperature thermal energy exchange systems with different thermal insulations of the heat exchange chamber;

[0086] FIG. 5 shows a complete high temperature thermal energy exchange system;

[0087] FIG. 6A shows the high temperature thermal energy exchange system in a charging mode;

[0088] FIG. 6B shows high temperature thermal energy exchange system in a discharging mode;

[0089] FIG. 7 shows the temperature front of a high temperature thermal energy exchange system concerning the invention in hands (solution c)) in comparison to a thermal energy exchange system concerning the state of the art (a) and b))and

[0090] FIG. 8 shows a valve design which is used for the high temperature thermal energy exchange system.

DETAILED DESCRIPTION

[0091] Core of this invention is a high temperature thermal energy exchange system 1 with a heat exchange chamber 11 on a high temperature level, which will be charged and discharged with thermal energy via a heat transfer fluid 13. Thermal energy is stored in the heat storage material 121.

[0092] The temperature level of the stored heat is significantly higher compared to methods applied so far to increase the efficiency. The temperature level lies between 300° C. and 800° C., preferably between 550° C. and 650° C. The thermal capacity of the high temperature thermal energy exchange system lies in the range between 0.3 GWh and 100 GWh, which causes a thermal power of 50 MW.

[0093] The high temperature thermal energy exchange system 1 comprises at least one heat exchange chamber 11 with chamber boundaries 111 which surround at least one heat exchange chamber interior 112 of the heat exchange chamber 11. The heat exchange chamber is a horizontal heat exchange chamber 114.

[0094] The chamber boundaries 111 comprise at least one inlet opening 1111 for guiding in an inflow 132 of at least one heat transfer fluid 131 into the heat exchange chamber interior 112 and at least one outlet opening 1112 for guiding an outflow 133 of the heat transfer fluid out of the heat exchange chamber interior 112. At least one heat storage material 121 is arranged in the heat exchange chamber interior 112 such that a heat exchange flow 13 of the heat transfer fluid 131 through the heat exchange chamber interior 112 causes a heat exchange between the heat storage material 121 and the heat transfer fluid 131.

[0095] The heat exchange chamber is at least partly integrated in the earth. An alternative embodiment of the high temperature thermal energy exchange system comprises a completely integrated heat exchange chamber.

[0096] The high temperature thermal energy exchange system 1 is equipped with a number of measuring devices 1500 for determining a charge status of the high temperature thermal energy exchange system 1. These measuring devices are distributed mainly in the heat exchange chamber 11.

[0097] The heat exchange chamber 11 is thermally insulated against the surrounding. There is a thermal insulation unit 300.

[0098] Different thermal insulation possibilities (thermal insulation stacks) are shown in FIGS. 4A, 4B and 4C. Concerning FIG. 6A the insulation unit 300 comprises a first insulation cover sheet (layer) 301. This first insulation cover sheet comprises gas concrete, for instance Ytong®. Alternatively this first insulation cover sheet comprises bricks, clay, ceramics, clinker, concrete, plaster, fiber reinforced plaster, and/or metal.

[0099] The next insulation layer 302 comprises mineral wool and/or rock wool. Alternatively this insulation layer 302 comprises foamed clay or glass concrete. Mixtures of these materials are possible, too.

[0100] A third insulation layer 303 completes the insulation unit: This third insulation layer 303 has the function of a supporting structure and comprises gas concrete (for instance Ytong® or clay), clinker, concrete, plaster, fiber reinforced plaster and/or metal.

[0101] Alternatively, the first insulation layer 301 is omitted FIG. 4B).

[0102] In a further alternative solution the thermal insulation unit 300 comprises an additional intermediate insulation cover layer 304 (FIG. 4C). This additional cover layer comprises Gas concrete, clay or ceramics and has the function of an additional supporting structure.

[0103] Exemplarily, the length 118 of the horizontal heat exchange chamber 11 is about 200 m, the height 119 of the heat exchange chamber 11 is about 10 m and the width of the heat exchange chamber 11 is about 50 m.

[0104] Alternatively, cylindrically shaped heat exchange chambers 113 are used.

[0105] The proposed high temperature thermal energy exchange system will store energy on a high temperature level, which can be used during discharging to produce steam in a water steam cycle for reconversion into electrical energy. Therefore, one or several heat exchange chambers filled with solid heat storage material are used. The solid heat storage material could be bulk storages material with sand, stones or gravels, rubbles, splits, clinkers, ceramics, slag and other bulk materials, for example basalt or iron silicate slag.

[0106] The solid materials can be used alone or can be mixed with other heat storage materials (e.g. due to limited availability of materials, in order to improve the flow behavior of the heat exchange flow of the heat transfer fluid through the heat exchange chamber interior or in order to improve the heat exchange between the heat storage material and the heat transfer fluid) for the use in the high temperature thermal energy exchange system. Different particle sizes or mixture of different particle sizes (improving flow behavior and energy density) can be used, too. As a result, the filling of the heat exchange chamber with heat storage material can be homogenous or inhomogeneous.

[0107] This solid bulk material is heated up and stores the energy over a long time period. The shape and the arrangement of one or several storages are according to the usage and the integration in a certain system. The shape of the base area depends on whether the storage will be built vertically with a vertical heat exchange chamber (no negative effect of natural convection) or horizontal (simple construction and incident flow, adaption to local conditions) as shown in FIGS. 1 and 2. The cross section of the heat exchange chamber will be a trapezoid.

[0108] There is a transition area 116 of the heat exchange chamber 11 with a tapering profile 1161. Thereby an opening diameter 1113 of the opening 1111 or 1112 aligns to a first tapering profile diameter 1162 of the tapering profile and a chamber diameter 117 of the heat exchange chamber 11 aligns to a second tapering profile diameter 1163 of the tapering profile (see FIG. 1, 2 or 3). The inflow 132 of the heat transfer fluid 13 is guided into the heat exchange chamber interior 112. The guided inflow is distributed to a wide area of heat storage material 121. By this measure a capacity of the complete heat exchange unit (heat storage material 121 which is located in the heat exchange chamber 11) can be utilized in an advantageous manner.

[0109] The transition area 116 is short. The transition area 116 comprises dimension 1162 which is less than 50% of a heat exchange chamber length 118 of the heat exchange chamber 11. The short transition area 116 projects into the heat exchange chamber 11. The result is a short transition channel for the guiding of the inflow 132 into the heat exchange chamber interior 112 of the heat exchange chamber 11.

[0110] In order to adapt the heat exchange flow 13 the high temperature thermal energy exchange system comprises a flow adjusting element 134. This flow adjusting element 134 is a blower.

[0111] Furthermore the heat exchange chamber 11 can comprise one or several inlet openings 1111 and outlet openings 1112 as shown in FIG. 3.

[0112] The high temperature thermal energy exchange system 1 is additionally equipped with at least one flow adjusting element 134. The flow adjusting element is an active fluid motion device (1341) like a blower or a pump. Such a device enables a transportation of the heat transfer fluid 131 through the heat exchange chamber interior 111 of the heat exchange chamber 11. The blower or the pump can be installed upstream or downstream of to the heat exchange chamber 11.

[0113] In addition, at least one passive fluid control 1342 device like a valve is located upstream or downstream of the heat exchange chamber 11.

[0114] The high temperature thermal energy exchange system 1 is developed such that horizontal heat exchange flows 140 and 141 of the heat transfer fluid through the heat exchange chamber interior 112 differ from each other in vertical direction. The mass flows are adjusted such that in case of a charging mode, the lower mass flow is larger than the upper (mass) flow (FIG. 7A). In case of a discharging mode the upper (mass) flow 141 is larger than a lower mass flow 140.

[0115] In order to manipulate the heat exchange flow 13 the high temperature thermal energy exchange system comprises a flow adjusting element 134. This flow adjusting element 134 is a passive fluid control device 1342 like a valve.

[0116] This storage is equipped with at least one flow adjusting device 134. The flow adjusting device is an active fluid motion device like a blower or a pump (134, 134). Such a device transports the heat transfer fluid 13 through the heat exchange chamber interior 11 of the heat exchange chamber 11. The blower or the pump can be installed upstream or downstream in comparison of the heat exchange chamber. For the charging mode the installation downstream is advantageous: Relatively cold heat transfer fluid passes the flow adjusting device after releasing of heat to the heat storage material. In contrast to that, in a discharging mode the upstream installation of the flow adjusting device is advantageous: Relatively cold heat transfer fluid passes the flow adjusting device before absorbing heat from the heat storage material

[0117] The horizontal heat exchange chamber can have inlet openings and outlet openings on top and bottom (decreasing natural convection) or preferably sideways (simple and inexpensive construction and simple incident flow).

[0118] The heat transfer fluid 13 enters the heat exchange chamber 11 through a (not shown) diffuser. The diffuser is arranged at the transition area 116 of the heat exchange chamber. Furthermore the heat transfer fluid can be liquid or gaseous, which also can be organic or inorganic. To guide the heat transfer fluid shutters and/or valves are used.

[0119] The temperature level of the stored heat is significantly higher compared to methods applied so far to increase the efficiency. The temperature level lies between 300° C. and 800° C., preferably between 550° C. and 650° C. The thermal capacity lies in the range between 1 GWh and 100 GWh, which causes a thermal power of 50 MW.

[0120] FIG. 2 show a horizontal heat exchange chamber 114. Thereby two inlet openings 1111 are arranged above as well as two outlet openings 1112. Theses openings comprise tapered transition areas 116. Again: Measuring devices 1500 for determining a charge status of the high temperature thermal energy exchange system are distributed in the heat exchange chamber.

[0121] Dependent on the usage and the demands, these capacity of the high temperature thermal energy exchange system can easily be adapted (heat storage material, dimensions of the heat exchange chamber, etc). For instance, for an increasing of the capacity of high temperature thermal energy exchange system the high temperature thermal energy exchange system is equipped with several storages chambers as shown in FIG. 3.

[0122] Therefore the heat exchange chambers can be arranged parallel, serial, in line, on top of each other or as single one. FIG. 3 show such an embodiment with a parallel arrangement: Three heat exchange chambers 11 form together a common storage unit.

[0123] Referring to FIG. 5, the complete charging and discharging system 1000 for a high temperature thermal energy exchange system 1 comprises one or several electrical heating devices 201, one or several machines to circulate the working fluid such as blowers 211 or pumps 1341 and one or several heat exchange chambers 11. The electrical heating devices 200 can be resistance heater 201, inductive heater or others. These devices are connected by a pipe or ducting system 1001. The high temperature thermal energy exchange system shown in FIG. 7 comprises a closed loop 1005.

[0124] For the charging mode, the heat transfer fluid 131 is heated up from ambient conditions by the electrical heater 201.

[0125] Alternatively, the heating (partial heating or complete heating) of the heat transfer fluid is carried out with the aid of waste heat e.g. from industrial or power plant processes or from geothermal sources with or without an electrical heating device.

[0126] This charged heat transfer fluid is guided into the heat exchange chamber interior 112 of the heat exchange chamber 11 for charging the heat storage material. Thereby the heat exchange between the heat transfer fluid and the heat storage material takes place. With reference 2000 the temperature front at a certain time of this charging process is shown.

[0127] This charged heat transfer fluid is guided into the heat exchange chamber interior 112 of the heat exchange chamber 11 for charging the heat storage material. Thereby the heat exchange between the heat transfer fluid and the heat storage material takes place. With reference 2000 the temperature front at a certain time of this charging process is shown.

[0128] The machine to circulate the heat transfer fluid 131 is preferably installed upstream or alternatively downstream of the electrical heating device or downstream of heat exchange chamber. Several heat exchange chambers 11 are combined for varying charge and discharge duration (not shown). Alternatively, just one heat exchange chamber 11 is used in order to cover the required storage capacity.

[0129] For the discharging mode the high temperature thermal energy exchange system comprises one or several heat exchange chambers 11 mentioned above, an active fluid motion control device 1341 to circulate the heat transfer fluid 131 and a thermal machine for re-electrification, which can be a water/steam cycle 1003. The working fluid of this cycle is water and steam. The water/steam cycle 1003 has the function of a discharging unit 400. With the aid of the heat exchange system (heat exchanger) 1002 thermal energy of the heat transfer fluid is transferred to the working fluid of the steam cycle 1002.

[0130] The different components of the high temperature thermal energy exchange system 1 are connected with a pipe or ducting system 1001. The flow adjusting element guides the heat transfer fluid through the heat exchange chamber of the high temperature thermal energy exchange system, thermal energy is transferred from the heat storage material 121 to the heat transfer fluid 131 and is transported to the thermal machines or further applications e.g. district heating, preheating of the discharge cycle, heating of different components of the high temperature thermal energy exchange system etc. If the thermal machine is a water steam cycle, a steam generator, a heat exchanger or an evaporator, which consist of one or several units, the thermal energy is transferred to water to generate steam which is fed to a thermal engine to produce electrical power as shown in FIG. 7. If the working fluid downstream of this thermal machine still contains thermal energy at a temperature level higher than ambient, this energy can be stored in the same heat exchange chamber or in another heat exchange chamber.

[0131] The complete system with all components in charge and discharge cycle for the thermal energy storage is shown in FIG. 5.

[0132] In an energy system with high penetration of renewable energy the profitability of fossil fueled thermal power plants suffers from low operation hours. This can lead to a complete shutdown of such plants for economic reasons.

[0133] In this case or in order to increase the flexibility the steam cycle of fossil fired power plants can be combined with the high temperature thermal energy storage system proposed here. Either the installed equipment is solely used to generate electrical energy with the stored thermal energy in a heat recovery process like in CCPP (combined cycle power plant) or the thermal storage is used to increase the flexibility of a thermal power plant. In the latter case the boiler is fired with fuel when fuel costs are lower than electricity costs and the storage is charged if electricity prices are low. Charging can take place during a period of excess production of energy.

[0134] The discharging mode can be realized when electricity prices and demand are high or when the production of renewable energies is low. Well suited are CCPP since their heat recovery steam generator (HRSG) is similar to the application proposed here. Nevertheless hard coal, oil, gas, waste incineration, wood or lignite fired power plants can be used since the heater device can be designed for high temperature to match the temperatures used in the steam generator. In a hybrid mode the fuel can be used to increase the temperature from the temperature level of the storage to the operating temperature of the original furnace or boiler design.

[0135] FIG. 7c show the advantage of the invention. The temperature 2000 divide the heat exchange chamber 11 in two parts: A cold part 14 and a hot part 15. The temperature distribution 2000 doesn't show large steps perpendicular to the flow direction like for conventional horizontal heat exchange chambers (FIG. 7b). This solution is similar to a vertical heat exchange chamber 17 (FIG. 7c).

[0136] FIGS. 8A and 8B show a valve design which is used for the flow adjusting element 134 (to be seen in different cross sections 1343). Main component is a rotatable flap 1344 that covers about 50% of the respective channel. The flap 1344 is made out of perforated material and withstands the temperature of the heat transfer fluid. The flap 1344 can be stopped by the stop unit 1345. The flap is rotatable by the bearing 1346 with the rotational axis 1347.

[0137] Looking at FIG. 8C a side view of the valve is depicted. The flap 1344 is rotatable around the rotational axis 1347 arranged and can be stopped by the stop unit 1345. The flow direction of flow 13 of the heat transfer fluid 13, of the lower horizontal flow 140 or of the upper horizontal flow 141 is depicted by the reference 1348.

[0138] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0139] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.