TOMKÓ, István (Völgykapu 1, Abaújkér, H-3882, HU)
TAKÁCS, János (Dózsa Gyõrgy u. 1, Mályi, H-3434, HU)
TOMKÓ, István (Völgykapu 1, Abaújkér, H-3882, HU)
TAKÁCS, János (Dózsa Gyõrgy u. 1, Mályi, H-3434, HU)
CLAIMS:
1. Closed energetic system for utilization of hot water heated by technologic waste heat or solar or geothermic way, consisting of solar collector units, absorption refrigerating system and electric power generating equipment, characterized by that,
the system consists of a heat production unit (1) consisting of solar collector groups (Ia, Ib, Ic); heat accumulating tanks (2; 4; 10) filled with phase changing materials operating at different temperature ranges; buffer water tanks (3; 5; 7; 9; 11; 13) operating at different temperature ranges, absorption refrigerating equipment (6) and cooling tower (8) providing its cooling.
2. System according to the claim 1 characterized by that, the system contains a current converter (15) and electric power generating equipment (14) with generator driven by a low temperature turbine.
3. System according to the claims 1 or 2, characterized by that, besides the solar collector groups (Ia, Ib, Ic), the heat production unit (1) contains heat extracting units for extracting the heat of thermal water or technologic waste heat or the combination thereof.
4. System according to the claims 1 to 3 characterized by that, temperature of the hot water coming from the heat extracting units of the heat production unit (1) is 70 - 95 0 C.
5. System according to the claims 1 to 4 characterized by that, if the temperature of the hot water coming from the heat extracting units of the heat production unit (1) does not reach 70 - 95 0 C, the heat production unit (1) is completed with an external heating apparatus (boiler) operating on solid, gas or liquid fuel or electric power.
6. System according to the claims 1 to 5 characterized by that, the absorption refrigerating equipment (6) and the heat production unit (1) are dimensioned such a way, that the cooling water of the temperature of 6 - 9 0 C obtained from the absorption refrigerating equipment (6) is suitable for air-conditioning of buildings and for the required technological purposes too.
7. System according to the claims 1-6 characterized by that, the absorption refrigerating equipment (6) and the heat production unit (1) and the heat extracting units are dimensioned such a way, that the hot water from the buffer tanks (3, 5, 7) of the temperature of 50 - 95 0 C is available for heating of buildings and for the required technological purposes too. |
Closed energetic system for utilization of hot water heated by technologic waste heat or solar or geothermic way
The subject of the invention is a closed energetic system for complex utilization of hot water heated by technologic waste heat or solar or geothermic way, which solution makes possible the continuous and complete utilization of hot water and lost heat heated by solar or geothermic way or by technological waste heat, by an installed and closed energetic system, through the whole year, in eveiy part of the day, thus reducing the consumption of energy taken from the expensive electric- and gas-distributing systems.
By these days the utilization of hot water and lost heat provided for by the nature or occurring as a byproduct of different technologies became a very important issue. With the help of modern vacuum tube solar collectors it is possible to develop hot water of a temperature of as high as 95 0 C even in moderate climatic zones. The hot water developed this way is used primarily for household hot water, household heating supplement or swimming pool heating. The two fundamental constraints of utilization of hot water produced with the help of a solar collector system are that it is depending on the time of the day - at night it is only available if stored - and on the season - can be produced in the largest quantity in summer -, but at that time it can be used only for household hot water, technological hot water and/or for heating of swimming pools at the outmost, but not for heating of buildings, thus in these periods natural absorption of surplus heat shall be provided for. Until now only hot water tanks were used for storage of thermal energy extracted with solar collectors, which required huge and expensive storage capacity for the continuous utilization (at night as well).
According to the state of the art, the patent description HU 207 152 titled "Solar energy utilizing equipment and collector unit and connection method for solar energy utilizing equipment" describes such a solar power utilizing equipment particularly for meeting the power demand of households, which contains at least one sunshine capturing collector unit adjustable via a moving unit, and an absorbing unit fixed on to the collector unit, and one or more heat recovering units. Further, it contains an absorber unit, a pipeline system consisting of an outgoing line connecting the absorber unit with the heat recovering unit and a returning line and the heat carrying agent circulating in the pipeline system. The pipeline system is equipped with one or more valves affecting the flow of the heat carrying agent and preferably a circulating apparatus. At least one of the heat recovering units is a stove, the stove has one or more cooking plates with a cavity inside them, inserted between the outgoing and returning lines, and a baffle and flow regulating fitting piece are placed inside the cavity of the cooking plates. The cooking plate itself is equipped with a valve, suitable for regulating the quantity of the heat carrying agent flowing through its cavity.
The patent description HU 215 196 describes a regulated heating and/or cooling and/or household hot water supplying system having collector element(s) operating on liquid and/or gas and/or steam heat carrying agent, utilizing thermal energy, preferably the solar energy, whose control input(s) is/are connected to one of the output of a controller, the inputs of which controller are connected to (a) detecting element(s) measuring climatic parameters of an outdoor and/or indoor space, and outputs are connected to (an)
actuating unit(s) matching to the given regulators. Its actuating unit, at least partially made from the collector element(s), is a thermal diaphragm connected to a color coupler unit made of a light- and/or thermal radiation transmitting material, containing at least one heat carrying agent with controllable heat transferring and/or light transferring properties.
Disadvantages of the above-described solutions are that they do not allow for the full and continuous utilization of the lost heat originating from the nature or generated as byproduct of technological processes and of the excess heat.
When working out the solution according to the invention we aimed to produce such a system which facilitates the whole, loss less and continuous utilization, through the whole year and all day long, of excess heat of hot water, heated by solar energy, geothermic energy or technologic waste heat, depending on the time of the day and on the seasons.
When creating the solution according to the invention we realized, that if we create such a closed energetic system, in which we install various equipment, such as heat accumulating tank for storing hot water, absorption refrigerating system for cooling powered by hot water, low temperature turbine generator suitable for generating electric power; for continuous loss less utilization of energy of hot water heated by technologic waste heat of various technologies or solar or geothermic way; then the set aim can be achieved.
The invention is a closed energetic system for utilization of hot water heated by technologic waste heat or solar or geothermic way, consisting of solar collector units, absorption refrigerating system and electric power generating equipment, and the system consists of a heat production unit consisting of solar collector groups; heat accumulating tanks filled with phase changing materials operating at different temperature ranges; buffer water tanks operating at different temperature ranges, absorption refrigerating equipment and cooling tower providing its cooling.
In one preferred embodiment of the solution according to the invention the system contains a current converter and electric power generating equipment with generator driven by a low temperature turbine.
In another preferred embodiment of the solution according to the invention besides the solar collector groups, the heat production unit contains heat-extracting units for extracting the heat of thermal water or technologic waste heat or the combination thereof.
In a further preferred embodiment of the solution according to the invention temperature of the hot water coming from the heat extracting units of the heat production unit is 70 - 95 0 C.
In a further preferred embodiment of the solution according to the invention if the temperature of the hot water coming from the heat extracting units of the heat production unit does not reach 70 - 95 0 C, the heat production unit is completed with an
external heating apparatus (boiler) operating on solid, gas or liquid fuel or electric power.
In a further preferred embodiment of the solution according to the invention the absorption refrigerating equipment and the heat production unit are dimensioned such a way, that the cooling water of the temperature of 6 - 9 0 C obtained from the absorption refrigerating equipment is suitable for air-conditioning of buildings and for the required technological purposes too.
In a further preferred embodiment of the solution according to the invention the absorption refrigerating equipment and the heat production unit and the heat extracting units are dimensioned such a way, that the hot water from the buffer tanks of the temperature of 50 - 95 0 C is available for heating of buildings and for the required technological purposes too.
The solution according to the invention is furthermore set forth by the enclosed drawing:
The process flow diagram of a possible realization of the closed, complex energy utilization system according to the invention is shown on Figure 1. Figure 1 shows the heat production unit 1 containing in this case three vacuum tube solar collector groups Ia, Ib, and Ic. From the solar collector groups Ia, Ib, Ic the hot water heated here flows to the heat accumulating tank 2 where the heat transfer takes place and from here the water flows to a buffer tank 3. If the water temperature is not adequate, the water flows back from the buffer tank 3 to the solar collector group Ic; if the water temperature is adequate, the water flows to the electric power generating equipment 14. The electric power generated this way in the electric power generating equipment 14 is lead to the network through the current converter 15. From the electric power generating equipment 14 the hot water flows to the absorption refrigerating equipment 6 through the heat accumulating tank 4 and the buffer tank 5. If the temperature of hot water leaving the buffer tank 5 is not adequate, the water is lead to the solar collector group Ib.
The absorption refrigerating equipment 6 produces the cold water required for cooling of the electric power generating equipment 14. The cold water produced by the absorption refrigerating equipment 6 is lead to the electric power generating equipment 14 through the heat accumulating tank 10 and buffer tank 11. The cold water leaving the electric power generating equipment 14 is lead back to the absorption refrigerating equipment 6. The cold water produced by the absorption refrigerating equipment 6 can be used for air-conditioning of buildings or serves other technologies requiring cold water. In this case the cold water flows from the buffer tank 11 through a different branch to heating/cooling water recovering unit 12 and from here it is lead back to the absorption refrigerating equipment 6. The water leaving the absorption refrigerating equipment 6 is lead back to the solar collector group Ia through the buffer tank 7. Cooling water of the absorption refrigerating equipment 6 is provided by the circuit consisting of the cooling tower 8 and buffer tank 9. Make-up of water losses occurring in the closed circuits of different temperatures is provided by buffer tank 13.
In one preferred concrete embodiment of the solution according to the invention the heat is produced in the heat production unit 1, where the hot water is produced in three vacuum tube solar collector groups Ia, Ib, and Ic. Inlet temperature of water at vacuum tube solar collector group Ia is 45 - 55 0 C, in case of continuous operation. However, at the time of starting the system, this value is equals to the temperature of water used from the network for filling the system, usually 12 - 15 0 C. The water of temperature of 65 - 70 0 C leaving the vacuum tube solar collector group Ia enters the vacuum tube solar collector group Ib, where is heated further to the temperature of 75 - 85 °C. The water is heated to the temperature of 95 0 C required for the operation of the whole system in the vacuum tube solar collector group Ic.
The heat production unit 1 could be any other heat source as well, for example thermal water, technological "waste" hot water produced in exhaust gas/water heater exchanger or the combination thereof.
From the heat production unit 1 the hot water flows through the inner heat exchanger of the heat accumulating tank 2 filled with Phase Change Material (PCM) and delivers the heat while the phase change occurs (heat accumulation). The hot water flows into the buffer tank 3. Role of buffer tanks 3, 5, 7, 9, 11, 13 of the system is to maintain the flow rate required for the system's operation. If temperature of water leaving the buffer tank 3 is lower than 80 0 C (for example when starting the system), the water from the tank is lead back to the solar collector group Ic. The hot water from buffer tank 3 flows to the low temperature turbine + generator (LTT) electric power generating equipment 14, where it heats up the special, low boiling temperature liquid driving the turbine and the steam generated from this special liquid drives the turbine, which turns the generator and thus the electric power generation starts. The electric power generated in the electric power generating equipment 14 i.e. in the low temperature turbine + generator unit is lead to the network and/or to the consumer appliances through the current converter 15.
The hot water leaves the electric power generating equipment 14 at a temperature of 75 - 85 °C and flows through the heat accumulating tank 4 to the buffer tank 5 providing for the heat demand of the absorption refrigerating equipment 6. If temperature of the hot water leaving the buffer tank 5 is lower than 70 0 C (for example when starting the system), the water is lead back to the solar collector group Ib, if it is higher than 70 0 C, the hot water is lead to the absorption refrigerating equipment 6.
The absorption refrigerating equipment 6 produces the cold water of the temperature of 6 - 9 0 C needed for cooling of the electric power generating equipment (LTT) 14. The cold water produced by the absorption refrigerating equipment 6 flows to the electric power generating equipment 14 through the heat accumulating tank (PCM) 10 and cold water buffer tank 11. The water leaving from here at a temperature of 15 - 20 °C is lead back to the absorption refrigerating equipment 6.
If cold water is needed not only for cooling of the electric power generating equipment 14 but for air-conditioning of buildings or for any technological purposes, then the absorption refrigerating equipment 6 shall be projected to cooling capacity extended with this value. In this case the cold water flows from the buffer tank 11 through a
separate branch to the building or technological cooling units of the heating/cooling water recovering unit 12 and from here the water flows back to the absorption refrigerating equipment 6. The water leaving the hot water branch - of a temperature of 45 - 55 0 C - flows back to the front end of the solar collector groups, to the solar collector group Ia through the buffer tank 7. If other kind of utilization (building and/or any technological heating) of the hot water of temperature of 45 - 55 0 C is required, then the water is lead to the building or technological heating units of the heating/cooling water recovering unit 12 through the buffer tank 7. The water cooled down (approximately 35 - 40 0 C) is lead from the heating/cooling water recovering units 12 to the solar collector group Ia.
Cooling water of the absorption refrigerating equipment 6 is provided by the circuit consisting of the cooling tower 8 and the cooling water buffer tank 9. Temperature of the cooling water entering into the absorption refrigerating equipment 6 is 20 - 25 0 C, temperature of the water leaving is 30 - 35 0 C. Make-up of water losses occurring in the closed circuits of different temperatures of the system is provided by buffer tank 13.
Besides the solar collector systems, the invention provides two solutions for the utilization of the surplus amount of the technologic waste heat (heat present in hot water and in exhaust gas) occurring in summer.
One of them is the cooling with hot water, which can be achieved by installing the hot water driven absorption refrigerating equipment 6 manufactured under license from SANYO. These pieces of absorption refrigerating equipment 6 are driven by hot water of temperature of 70 - 80 0 C and produce cold water of temperature of 5 - 7 0 C. Their capacity varies widely depending on the manufacturer (between 10 RT - 3000 RT). '
Another possibility for utilization of the surplus hot water in summer is the electric power generating equipment 14 driven by the so called Low Temperature Turbine (LTT) generators. The characteristic property of the LTTs is that the turbine is a hermetically closed, high pressure circuit where such a liquid of low boiling temperature is used, with which suitably high pressure can be produced by heating with hot water of temperature of 70 - 90 0 C for driving the micro-turbines. Such technology is for example the Add Power Turbine manufactured under a Swedish patent, with a capacity of 1.5 MW e , or the American so called PureCycle System (an LTT converted from absorption cooling equipment with turbo-compressor + generator) with a capacity of 200 kW e . Efficiency of the LTT systems is 20 - 30%. Widespread application of LTT systems is prevented on one hand by the required temperature difference of 65 0 C between the hot water and the LTT cooling water, meaning cooling water of temperature of 5 - 15 0 C and on the other hand by the requirement of a large quantity of cooling water of a very low temperature due to the efficiency of 20 - 30% of the LTT systems (for example 1500 1/minute of cooling water of temperature of 5 - 15 0 C. In case of flow-through type cooling it requires water intake and water treatment installations.
In the closed system according to the invention, cooling water of the LTT is also produced by the hot water driven absorption refrigerating equipment 6, temperature of
which is suitably low (5 - 7 0 C), shifting at the same time efficiency of the electric power generation towards the 30% value. Temperature of the cooling water is 25 - 30 0 C at the absorption refrigerating equipment 6 producing the cooling water for the LTT, which can also be produced even with air-cooled devices. For example, an absorption refrigerating equipment 6 of 600 - 900 RT is suitable for producing the cooling water of the PureCycle of capacity of 200 kW.
Until now only hot water storage tanks were used for storage of the thermic heat gained by solar collectors which required large and expensive storage capacities to ensure the continuous utilization (even in the night). In the solution according to the invention the heat is stored not only in water tanks but also in tanks filled with so called Phase Change Materials (PCM). The PCM materials store/release the heat as "latent heat" absorbed or released at their phase changes (for example melting/freezing, mellowing/setting) providing higher storage capacity by an order of magnitude than the water with a specific heat capacity of (4,2 kJ/kg*K). The most commonly known PCM storage materials in the temperature range of hot water systems are the various paraffin (wax) derivatives, as seen in the following table:
1 Maximum melting temperature for the DSC melting curve (Differential Scanning
Calorimeter) 2 Temperature border element <=15 0 C
The transfer of heat between the water/phase change materials (PCM) in the system in our example is provided by the heat exchangers within the units (heat accumulating tanks).
List of references:
1 - heat production unit Ia - solar collector group Ib - solar collector group Ic - solar collector group
2 - heat accumulating tank
3 - buffer tank
4 - heat accumulating tank
5 - buffer tank
6 - absorption refrigerating equipment 7 - buffer tank
8 - cooling tower 9 - buffer tank
10 - heat accumulating tank
11 - buffer tank
12 - heating/cooling water recovering unit 13 - buffer tank
14 - electric power generating equipment
15 - current converter