Additions to patent application 10 2013 020 686.3 Low-temperature steam process (low-temperature organic Rankine cycle, abbreviated: TT-ORC) for optimizing conventional steam processes and for generating energy (electricity) from ambient heat

Abstract

Title: Amendments to patent application file number 10 2013 020 686.3 (Low-temperature steam process [Low-temperature Organic Rankine Cycle, abbreviated: TT-ORC] for optimizing conventional steam processes and for generating energy (electricity) from ambient heat). The inventions described below in this patent application are all to be understood as amendments to patent application 10 2013 020 686.3. Some are clarifications of the original application, while others extend or modify its basic processes, both clockwise and counterclockwise. The numbering of the patent amendments corresponds to the numbering of the patent claims.

Description

[0001] Title: Amendments to patent application file number 10 2013 020 686.3 (Low-temperature steam process [Low-temperature Organic Rankine Cycle, abbreviated: TT-ORC] for optimizing conventional steam processes and for generating energy (electricity) from ambient heat).

[0002] The inventions described below in this patent application are all to be understood as amendments to patent application 10 2013 020 686.3. Some are clarifications of the original application, while others extend or modify its basic processes, both clockwise and counterclockwise. The numbering of the patent amendments below also corresponds to the numbering of the patent claims. Supplement No. 1 (clarification), temperature equalizer:

[0003] In the 2013 patent application, the temperature equalizer circuit, which could also be described as a "refrigerant diluter," was not yet defined in detail in the patent claims. After heating by the heat pump (operational chiller), the TT-ORC working fluid is still very cold; in a nitrogen process, the temperature could be around -150°C. If the ambient heat were brought into direct contact with the TT-ORC working fluid, without the buffer circuit of the temperature equalizer, the heat exchanger would freeze instantly if water were the heat source, and it would also ice up very quickly if air were the heat source. Therefore, a second heat exchanger, referred to as the TT-ORC main heat exchanger B, is connected upstream of this heat exchanger, the ambient heat exchanger A. Both heat exchangers are connected to each other via a circulation pump e and an expansion tank between their inlets and outlets (c and d), see [reference]. Fig. 1. A frost-resistant working fluid, such as liquid propane with a melting point of -190°C, circulates in this buffer circuit. The TT-ORC main heat exchanger B can either dissipate the ambient heat absorbed from the buffer circuit directly by being directly exposed to the working fluid vapor, or it can release it indirectly by heating another circuit filled with liquid propane. This second circuit, in turn, supplies ambient heat to the main superheaters of the live steam and reheat units, and possibly also to the steam generator. This second liquid propane circuit is driven by another circulation pump f and incorporates several three-way valves that regulate the heat quantities required for the individual main circuits (live steam and reheat units).

[0004] The same amount of heat flows through both heat exchangers A and B during the same period. The TT-ORC main heat exchanger B is filled with either nitrogen or liquid butane at a relatively low flow rate and a large temperature difference, e.g., -151°C to -101°C. The ambient heat exchanger A is filled with water or air at a high flow rate and a small temperature difference, e.g., +10°C to +2°C. Short-term fluctuations in the heat flow rates can be dampened by the large masses of liquid propane in the buffer circuit's expansion tanks. The flow rate of the liquid propane in the buffer circuit ensures that the temperature in expansion tank c never drops below 0°C, thus effectively preventing heat exchanger A from freezing. Supplement No. 2 (clarification), steam switch:

[0005] To ensure the most optimal integration of the operating refrigeration unit into the TT-ORC, its main lines are split into several sub-lines. For this purpose, several steam diverters are installed in the steam channels. These were not yet defined in detail in the 2013 patent application.

[0006] For steam switches, the steam channels are designed in a Y-shape. The steam flows into the switch at the base of the Y and exits at the ends of the two arms. The steam flow in the two arms is adjusted via a regulator blade, which is rotatably mounted at the intersection of the two arms (see figure). Fig. 2. Supplement No. 3 (Extension), first optimization measure for the heat pump, (operational chiller):

[0007] The TT-ORC's operating refrigeration unit is designed as a multi-stage cold steam process with flooded evaporators, see left side in Fig. 1 of patent application 10 2013 020 686.3. This basic circuit can be further optimized by transferring some of the superheat to the evaporators above the next higher evaporator. This optimization measure is applied in the lower temperature range of the operating refrigeration unit, where heat transfer to the TT-ORC is not yet possible.

[0008] In vapor-compression processes, the compressor draws saturated vapor from the evaporator and compresses it. During compression, the saturated vapor undergoes superheating; this superheating is greater the higher the isentropic exponent of the refrigerant. Since the operating temperature range of the refrigeration unit is very low, there are no specially developed refrigerants with particularly low isentropic exponents; gases with higher exponents must be used, sometimes even noble gases with particularly high values. This means that the final superheating temperature is not only higher than the condensation temperature of the next higher evaporator, but also higher than those of the subsequent ones (see figure). Fig. 3b, T4 is still above T3. For noble gases, the temperature difference T4 - T1 is a multiple of the temperature difference T1 - T0. This makes it possible to transfer some of the superheat from the lower process to the evaporators above the next higher evaporator. For this purpose, heat exchangers are installed in these higher evaporators, below their liquid levels, and connected in series, see [reference]. Fig. 3a. The superheated steam first enters the heat exchanger of the uppermost evaporator, releases the uppermost part of the superheat there, and then flows on to the heat exchanger of the next evaporator and releases the next part of the superheat there, etc., until it reaches the evaporator located next to the lowest evaporator, releases the last part of the superheat there and condenses.

[0009] The basic principle of a refrigeration machine is to raise a quantity of heat to a higher temperature. This principle is implemented almost ideally with the help of the optimization measure. In a refrigeration machine in its basic configuration, without the optimization measure, the condensation heat of the lower evaporator, plus all the compressor work converted into heat from the first process, must always be dissipated from the next higher evaporator, again requiring compressor work. With the optimization measure, some of the compressor work converted into heat is released at higher temperatures / evaporators and therefore no longer needs to be removed from the next higher evaporator by expending compressor work. Supplement No. 4 (Extension), Optimization measures 2a and 2b for the heat pump (operational chiller):

[0010] Both optimization measures are based on the same principle: an additional counterflow heat exchanger is integrated into the refrigerant circuit. The principle underlying heat transfer in heat exchangers—cooling the warm medium to the temperature of the cold medium, and conversely, heating the cold medium to its maximum temperature—is most ideally implemented in counterflow heat exchangers. These two measures aim to improve both the heat transfer of the heat pump process (2a) and the heat dissipation (2b). The optimization measures are applied in the upper temperature range of the operating chiller, where heat dissipation to the TT-ORC is already possible. Optimization measure 2a:

[0011] For this measure, a counterflow heat exchanger is connected between the condenser and the throttle valve, see Fig. 4a. This circuit was already described in patent application 10 2013 020 686.3, but only "one" heat exchanger was mentioned there, without specifying the effective flow principle. Therefore, it is explicitly defined here that a counterflow heat exchanger is to be used. This heat exchanger makes it possible to utilize the enthalpy difference of the condensate cooling for the heat pump process. After the refrigerant has been liquefied in the condenser and has released its heat of condensation, the enthalpy difference h3 - h4, see Fig. 4b, the refrigerant is cooled by the counterflow heat exchanger E down to the evaporator temperature, thereby transferring the enthalpy difference h4 - h5 to a partial flow of the TT-ORC working fluid, which is thereby heated from T0 to the condensation temperature. This circuit makes it possible to utilize the entire cooling capacity h1 - h6 available at T0 without any change in the compressor work h2 - h1, whereas the conventional process can only utilize the enthalpy difference h1 - h7. Likewise, without increasing the compressor work, the amount of heat delivered by the heat pump at the condensation temperature is increased by the enthalpy difference h4 - h5. Optimization measure 2b:

[0012] For this measure, a counterflow heat exchanger is connected between the compressor and the condenser, see Fig. 4a. By separately discharging the heat of heat removal h2 - h3, it is possible to heat a partial flow of the TT-ORC working fluid not only to the condensation temperature, but also to the superheating end temperature, see Fig. 4b. As already mentioned in optimization measure 1, the basic principle of a heat pump or chiller is to raise a quantity of heat to a higher temperature. By ensuring that part of the heat transfer occurs at a temperature higher than the condensation temperature, the efficiency of the heat pump is improved.

[0013] To ensure that the three heat quantities of the heat of heat loss, the heat of condensation and the heat of condensate cooling are considered, see Fig. 4b, which can be supplied separately to the TT-ORC working medium, their main lines, the live steam line and the reheat lines, must be split into several sub-lines. This splitting is carried out with the help of several successive steam diverters, see Fig. 4c, in more than two sub-strands, as provided for in patent 10 2013 020 686.3. In the sub-strands, the TT-ORC heat exchangers are connected in series on the working fluid side. Since the temperature ranges of the superheats overlap, see Fig. 3b and Fig. 4c , more than one sub-string must be provided for the counterflow heat exchangers for deheating. Supplement No. 5 (Extension), several TT-ORC units connected to each other:

[0014] Supplement No. 5 provides for arranging two or more TT-ORCs one below the other on the temperature scale, see Fig. 5. The lower TT-ORCs are heated by the waste heat from the TT-ORCs above them. It is possible to insert another TT-ORC between the temperature range of the nitrogen TT-ORC and the ambient temperature. A third TT-ORC could also be arranged below the nitrogen TT-ORC, which could potentially be operated with neon or a gas mixture with neon as the main component. To prevent the main capacitors from freezing, the individual TT-ORCs are interconnected by temperature equalization circuits, as already described in Supplement No. 1. Since the waste heat is transferred to the TT-ORCs below, only the lowest TT-ORC needs to be equipped with an operating refrigeration unit, as already explained in Patent 10 2013 020 686.3.This interconnection results in significantly less waste heat and significantly more work being generated in the multi-stage process than in the single-stage TT-ORC, thereby significantly increasing the efficiency once again. Supplement No. 6 (Amendment), temperature range of the TT-ORC partially above the ambient temperature:

[0015] Amendment No. 6 proposes raising the temperature range of the TT-ORC so that its maximum temperature is slightly above ambient temperature. This also increases the minimum temperature, the temperature in the main condenser of the TT-ORC. This allows the selection of working fluids for both the TT-ORC and the steam processes of the heat pump (operational chiller) whose vapor pressure curves are located higher on the temperature scale than those of the previous TT-ORC. This also results in lower standby pressures—the pressures that occur when the entire system is idle for an extended period and heats up to ambient temperature. Both the heat exchangers and the entire piping system and machinery then only need to be designed for these lower pressures.

[0016] Since the ambient heat cannot raise the TT-ORC above the ambient temperature, this area must also be heated by the heat pump. The TT-ORC is then subdivided into four temperature zones, see [reference]. Fig. 6a , the area of ​​regenerative preheating (A), the area of ​​the heat pump below the ambient temperature (B), the area heated by the ambient heat (C), and finally the area heated by the heat pump above the ambient temperature (D) . Supplement No. 7 (amendment), dual steam generation, live steam preheating and reheating for Supplement No. 6:

[0017] In the circuit variant of Supplement No. 6, the area heated by ambient heat can either be heated exclusively by ambient heat, or the live steam line and possibly also the first intermediate superheater can be split into two sub-lines by means of a steam diverter valve each. Optimization measure 2a (Supplement No. 4) for the heat pump can then be implemented in the smaller sub-lines. For this purpose, several TT-ORC condensate cooling counterflow heat exchangers are connected in series on the working fluid side of these sub-lines, while the main lines are heated by ambient heat (see diagram). Fig. 6b. Supplement No. 8 (Extension), regenerative steam drying of intermediate superheats:

[0018] For supplement No. 8, the superheating temperatures of both the live steam and the intermediate superheating are reduced compared to the values ​​of patent 10 2013 020 686.3 to such an extent that the temperatures of the vapors after the partial expansions are directly above the condensation temperatures, thereby creating a specific vapor wetness in each case.

[0019] The proportion of waste heat fed back into the system through regeneration can be further increased by also regeneratively heating the lowest part of the intermediate superheating stages, the steam drying stages. For this purpose, additional heat exchangers are installed between the heat pump-heated preheaters and the steam cylinders (see [reference]). Fig. 7, which are heated by the condensation heat of extraction vapors diverted shortly before the ends of the partial expansions. The condensates of these extraction vapors, just like the condensates of the extraction vapors from the regenerative food preparation preheating, are pumped back into the system during regeneration.

[0020] This measure results in even less exhaust steam reaching the main condenser, and the heat pump (operating chiller) has to expend even less compressor work to feed the waste heat back into the TT-ORC system; only slightly more work is required from the condensate pumps. Supplement No. 9 (Extension), complete regenerative heating of intermediate superheats:

[0021] For intermediate superheats where the maximum temperature is below the critical temperature of the working fluid, heating can also be carried out entirely regeneratively. Following the principle of regenerative boiler feedwater preheating, several heat exchangers are connected in series and heated by extraction vapors that were diverted at different pressures during the previous stage of the steam cylinder set. Due to these pressure differences, the extraction vapors condense at different temperatures, thus heating the intermediate superheats stepwise to their maximum temperature. The condensates from these extraction vapors, as well as those from the extraction vapors of the feedwater preheating, are then pumped back into the TT-ORC system in the regeneration section. This further reduces the amount of steam arriving at the main condenser, and consequently, the amount of heat that needs to be dissipated by the compressor. Supplement No. 10 (Amendment), TT-ORC as a saturated steam process:

[0022] Supplement 10 stipulates that the TT-ORC can also be implemented as a saturated steam process. The live steam superheater is omitted, and the previous intermediate superheating steps are performed as steam drying. Supplement No. 11, Vapor Discharge and Collection System:

[0023] To ensure that the TT-ORC loses absolutely no working fluid to the outside, a measure consisting of two subsystems is provided for the extraction and collection of vapors.

[0024] The first measure consists of a multi-chamber system. Both the piston rod and the rod (or shaft) of the valve actuation are sealed with several seals connected in series. Small gaps are arranged between the seals, creating several annular chambers, see [reference]. Fig. 8a. Thin steam lines are connected to these, leading to the next lower pressure levels. The steam escaping from the first high-pressure cylinder through the first seal enters the first chamber and is routed to the line for the first intermediate superheater. The steam that still penetrates the seal to the second chamber is routed to the line for the second intermediate superheater, and so on. The seals of the other steam cylinders are constructed in the same manner, with a smaller number of annular chambers in each case.

[0025] The second measure consists of an evacuated pressure vessel in which the steam cylinders, along with the power transmission linkages, the valve control linkages and the flywheel, including the generator, are housed, see Fig.8b. The last remaining vapor that penetrates the final seals is collected in the pressure vessel and, by means of a condenser located at the bottom of the pressure vessel, is condensed back into liquid and pumped back into the TT-ORC system. The condenser is connected to the lowest stage of the heat pump (operating chiller) and is maintained by it at the triple point temperature of the TT-ORC working fluid.

[0026] Completely avoiding vapors is strongly recommended for three reasons: firstly, to avoid the need to refill refrigerants; secondly, when using a toxic refrigerant, such as nitrogen monoxide, to prevent any toxins from entering the environment; and thirdly, the pressure vessel prevents ambient air from entering the negative pressure area of ​​the TT-ORC. Reference numeral list, Fig. 1

[0027] Temperature adjuster “cold diluter” A ambient heat exchanger B TT-ORC main heat exchanger c Expansion tank 1 d expansion tank 2 Circulation pump buffer circuit Circulation pump, ambient heat circuit, steam generator and main superheater, live steam and superheaters Reference numeral list, Fig. 4a

[0028] Optimized heat pump process A evaporator B compressor C Deheating counterflow heat exchanger D capacitor E Condensate cooling counterflow heat exchanger F Throttle valve Reference symbol list, Fig. 4c

[0029] Splitting of the TT-ORC main strands a condensate cooling counterflow heat exchanger b capacitors c. Deheating counterflow heat exchanger d steam switches List of reference symbols, Fig. 6a

[0030] Maximum temperature of the TT-ORC above the ambient temperature A Heating through regenerative preheating B “ “ Heat pump (operating chiller) below ambient temperature C Heating by ambient heat D “ “ Heat pump (operating chiller) above ambient temperature 1 Temperature after fresh steam superheating 2 “ “ 1. Partial expansion 3 “ “ 1. Intermediate overheating 4 “ “ 2nd partial expansion 5 “ “ 2. Intermediate overheating 6 “ “ 3. Partial expansion 7 “ “ 3. Intermediate overheating 8 “ “ 4. Partial expansion Reference symbol list, Fig. 6b

[0031] Dual steam generation and live steam preheating 1 Food / Utility Preheater 2 steam diverter 3a,b Heat pump condensate cooling heat exchanger (steam generation) 3c “ “ “ (Fresh steam preheating) 4a,b “ “ " (Fresh steam main superheating.) DE Steam generator 5 fresh steam preheaters, ambient heat heated 6a, b " -Main superheater, heat pump-heated Reference numeral list, Fig. 7

[0032] regenerative steam drying 1.ZÜ first intermediate overheating 2.ZÜ second " 3.ZÜ third " G Generator K TT-ORC main capacitor SP TT-ORC main feed pump H1 first high-pressure cylinder H2 second " M Medium pressure cylinder N Low-pressure cylinders DE Steam generator, ambient heat heated 1 ambient heat-heated heat exchanger, main superheater and steam generator 2 heat exchangers, heat pump-heated, food / working material preheater and pre-superheater, intermediate superheats 3 regeneratively heated heat exchangers, steam drying of the intermediate superheats QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 10 2013 020 686.3

[0002]

Claims

[1] (Temperature adjuster): The temperature equalizer circuit is a buffer circuit that prevents the heat exchanger through which the TT-ORC absorbs ambient heat from freezing. A second heat exchanger, the TT-ORC main heat exchanger, is connected upstream of this ambient heat exchanger. Both heat exchangers are connected via a circulation pump and an expansion tank between their inlets and outlets. A frost-resistant working fluid (e.g., liquid butane, melting point -190°C) flows through this buffer circuit. The TT-ORC main heat exchanger transfers the ambient heat to the TT-ORC either directly, through which the TT-ORC's working fluid vapor flows, or indirectly, by feeding another circuit with frost-resistant working fluid. Three-way valves are connected to the circuit to regulate the heat quantities for the TT-ORC main lines, the fresh steam, and the intermediate superheats. The same amount of heat flows through both heat exchangers over the same period of time: in the ambient heat exchanger, at a high mass flow rate and a small temperature difference (close to the ambient temperature), and in the TT-ORC main heat exchanger, at a low mass flow rate and a large temperature difference (at a low temperature). The flow rate of the frost-resistant working fluid in the buffer circuit ensures that the temperature in the expansion tank feeding the ambient heat exchanger is never lower than 0°C. This effectively prevents the ambient heat exchanger from freezing. [2] Steam switches for the TT-ORC main lines, characterized byThe steam ducts are designed in a Y-shaped pattern. The steam flows into the switch at the base of the Y and exits again at the ends of the two arms. The steam flow in the two arms is adjusted via a control dial mounted on a pivot at the intersection point of the two arms. [3] Optimization measure 1 for the heat pump, (operational refrigeration machine), characterized by In a multi-stage refrigeration machine with flooded evaporators, heat exchangers are installed in the evaporators above the next higher evaporator (the condenser of the lower process), and these are connected in series. A steam line leads from the compressor to the uppermost heat exchanger, from there to the next lower heat exchanger, and so on, to the condenser (the next higher evaporator of the lower process). The superheated steam first releases the uppermost portion of its superheat in the uppermost heat exchanger. It then flows into the heat exchanger below, releases the next part of the superheat, and so on up to the condenser. This reduces the amount of heat that has to be removed from the condenser (the next higher evaporator) using compressor work. [4] Optimization measures 2a and 2b for the heat pump (operational refrigeration machine), characterized bythat two additional heat exchangers designed according to the counterflow principle are connected to the heat pump's refrigerant circuit. The first counterflow heat exchanger, the condensate cooling counterflow heat exchanger, is connected between the condenser and the throttle valve (optimization measure 2a), and the second counterflow heat exchanger, the desuperheating counterflow heat exchanger, is connected between the compressor and the condenser (optimization measure 2b). All three heat exchangers, the two counterflow heat exchangers and the condenser, transfer their heat to the TT-ORC working fluid. To release the various heat quantities separately, the main lines of the TT-ORC, consisting of the fresh steam line and the intermediate superheaters, are split into several sub-lines by several steam switches connected in series. The heat exchangers of the individual heat pump stages are connected in series on the TT-ORC working fluid side in the sub-lines.The heat dissipation takes place in several sub-strands due to the overlapping temperature ranges of the refrigerant superheats. [5] Optimization measure for low-temperature Organic Rankine Cycle, characterized by The temperature ranges of several TT-ORCs are arranged one below the other on the temperature scale. The TT-ORCs above heat the TT-ORCs below with their waste heat. The individual TT-ORCs are connected to each other via temperature equalization circuits, as set out in claim 1. The TT-ORCs above are designed without a heat pump (operating chiller); only the lowest TT-ORC is equipped with one, as described in patent 10 2013 020 686.

3. This connection increases the work generated and reduces the waste heat generated, which increases efficiency. [6] Modification of the basic circuit of the TT-ORC (patent claim 1 of 10 2013 020 686.3), characterized by The temperature range of the TT-ORC is increased so that its maximum temperature is slightly above the ambient temperature. The temperature range between the ambient temperature and the maximum temperature is heated by the heat pump (operating refrigeration machine). [7] dual steam generation and live steam pre-superheating, or also intermediate superheating, for claim 6, characterized byThe first main branch, consisting of the steam generator and the main steam pre-superheater, or additional main branches consisting of the intermediate superheaters, are split into two sub-branch sections via steam switches. One sub-branch is heated by the heat pump (operating chiller), and the other sub-branch is heated by ambient heat. In the sub-branch heated by the heat pump, several condensate cooling counterflow heat exchangers (TT-ORC) are connected in series on the working fluid side. [8] regenerative steam drying of the intermediate superheats, characterized byThe basic circuit of patent 10 2013 020 686.3 is expanded by placing an additional heat exchanger between the steam cylinders and the heat-pump-heated preheaters of the intermediate superheaters. These heat exchangers are heated by extraction vapors diverted shortly before the end of the partial expansions. The released condensation heat dries the intermediate superheat vapors. The condensates from the extraction vapors, as well as the condensates from the feed fluid preheating, are pumped back into the TT-ORC system in the regeneration area by condensate pumps. [9] complete regenerative heating of intermediate superheats, characterized byThe circuit of claim 8 is expanded by connecting several heat exchangers in series according to the principle of regenerative boiler feedwater preheating, heating the intermediate superheats to maximum values. The heat exchangers receive their heat from extraction vapors, which are branched off at different pressures in the previous steam cylinder set and condense at different temperatures. The condensates from these extraction vapors, as well as the condensates from the feedwater preheating, are pumped back into the TT-ORC system by condensate pumps in the regeneration area. [10] the TT-ORC is designed as a saturated steam process, characterized by that the basic circuit of patent 10 2013 020 686.3 is modified by omitting the main steam superheater and the “intermediate superheaters” working as steam dryers. [11] Steam extraction and collection system: To ensure that the TT-ORC does not lose any working fluid to the outside, a measure consisting of two subsystems is provided for the discharge and collection of exhaust vapors. The first measure consists of a multi-chamber system. Both the piston rod and the rod (or shaft) of the valve actuator are sealed with several seals arranged in series. Small gaps are arranged between the seals, creating several annular chambers, see Fig. 8a . Thin steam lines are connected to these, leading to the next lower pressure levels. The exhaust steam escaping from the first high-pressure cylinder through the first seal enters the first chamber and is passed on to the line for the first intermediate superheater. The steam that still penetrates the seal to the second chamber is passed on to the line for the second intermediate superheater, and so on. The seals of the other steam cylinders are designed in the same way, with a smaller number of annular chambers. The second measure consists of an evacuated pressure vessel, which houses the steam cylinders, including the power transmission rods, the valve control rods, and the flywheel, including the generator. The last remaining vapor that still penetrates the final seals is collected in the pressure vessel and, using a condenser located at the bottom of the pressure vessel, liquefied and pumped back into the TT-ORC system. The condenser is connected to the lowest stage of the heat pump (operating chiller), which maintains the triple-point temperature of the TT-ORC's working fluid.

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