An energy system to produce water

Abstract

An energy system converts the latent heat energy of moist air into water and in some examples also to motive energy in dry exhaust air. It does this by flash evaporation (5) of primary air which has added water droplets (6), the supersonic speed of the primary flow from the flash evaporation nozzle creating suction to draw in ambient secondary air. A condenser tube (10) with a mixing throat (12) enhances the mixed primary / secondary air speed and causes condensation within the volume of the tube without need for heat exchanger surfaces, to provide output water and dry air at a pressure higher than atmospheric and thus providing thrust / power.

Description

[0001] “An Energy System to Produce Water”

[0002] Introduction

[0003] The present invention relates to the production of water as a liquid drawn from air.

[0004] US10,955,147 (Prince Mohammad Bin Fayd University) describes a supersonic conduit system and method for dehumidifying air.

[0005] W02009 / 116889 (Siemens) describes a system with a compressor and mixing of a cold gas with waste air in supersonic flow conditions.

[0006] US10,968,886 (Caren) describes an airfoil and turbine apparatus which has an induced supersonic flow through the apparatus.

[0007] US4, 141,701 (Ewan et al) describes removal of pollutant material from gas streams. It takes in ambient air and outlet air is fed through a compressor.

[0008] In many geographical regions, especially between the latitudes of + / - 30° the ambient air can hold in the range of 10 to 25 g / m3.

[0009] An objective is to achieve improved efficiency in water extraction from such air, and a secondary objective is to achieve improved motive energy output drawn from humidity in the air.

[0010] Summary of the Invention

[0011] We describe an energy system comprising an energy capturing device comprising: a controller linked to sensors and configured to perform control of the system using sensor inputs, an inlet for ambient air, a compressor configured to compress the inlet ambient air to a pressure of greater than 1.1 bar to provide a primary flow, a flash evaporation supersonic nozzle arranged to receive the primary flow to increase speed for the primary flow to be supersonic, a water supply arranged to provide water droplets into the primary flow, and a condenser arranged to mix a secondary flow of air with the primary flow and to condense the mixed primary and secondary flows.

[0012] Preferably, the condenser comprises a tube aligned with the nozzle.

[0013] Preferably, the condenser tube comprises: an inlet section to receive the supersonic primary flow from the nozzle and to allow inflow of ambient secondary air caused by suction around the supersonic primary flow so that the primary and secondary flows are mixed, a mixing throat configured to speed up the mixed air to provide a mixed flow and allow condensation of the mixed flow within the volume of the condenser tube, and an outlet diffuser section to provide outlet liquid water and exhaust air

[0014] In some preferred examples, the system further comprises a pressure stabilizing chamber between the compressor and the nozzle.

[0015] In some preferred examples, the compressor is configured to compress the inlet ambient air to a pressure in the range of 1.1 bar to 3.0 bar, preferably 1.2 bar to 3.0 bar, and more preferably 1.4 bar to 2.0 bar.

[0016] In some preferred examples, the water supply is configured to collect and feed back a portion of the outlet water.

[0017] In some preferred examples, the water supply comprises a heater to heat the water.

[0018] In some preferred examples, the heater is adapted to heat the water to a temperature in the range of 10°C to 95°C, thereby controlling the rate of flash evaporation.

[0019] In some preferred examples, the heater is adapted to heat the water to a temperature in the range of 60°C to 90°C.

[0020] In some preferred examples, the water injector provides droplets having a size in the range of 5 pm to 100 pm.

[0021] In some preferred examples, the water supply is configured to provide water injection flow by weight to compressed air weight in the range of 1 :500 to 1 : 10,000, preferably 1 : 1000 to 1 :10,000. In some preferred examples, the ratio by weight of water supply to the primary flow to compressed air supply to the nozzle is in the range of 1 : 1,000 to 1 : 10,000.

[0022] In some preferred examples, the flash evaporation supersonic nozzle comprises a flared outlet.

[0023] In some preferred examples, the flared outlet is located within the condenser tube inlet section.

[0024] In some preferred examples, the flash evaporation supersonic nozzle comprises an adjustable axial needle to vary outlet air nozzle outlet flowrate.

[0025] In some preferred examples, the compressor and the flash evaporation supersonic nozzle are configured to provide a primary flow speed into the condenser tube in excess of Mach 1.1, preferably in excess of Mach 1.5.

[0026] In some preferred examples, the condenser is configured to reduce the mixed air speed in the mixing throat to a speed which is still in excess of Mach 1.1, preferably in excess of Mach 1.2.

[0027] In some preferred examples, the flash evaporation supersonic nozzle and the compressor are configured to provide a temperature reduction in the range of 80°C to 150°C, for example from + 30°C to -90°C at the outlet of said nozzle.

[0028] In some preferred examples, the ratio of cross-sectional area of the flash evaporation supersonic nozzle (5) opening to the condenser inlet section is in the range of 1 :20 to 1 : 100, preferably 1 :20 to 1 :50.

[0029] In some preferred examples, the decrease in cross-sectional area between the condenser tube inlet and the mixing throat is in the range of 10% to 50%.

[0030] In some preferred examples, the increase in cross-sectional area between the condenser tube mixing throat (12) and the outlet section (13) is in the range of 200% to 8000%.

[0031] We also describe a method for producing water, the method performed by an energy system of any example, the method comprising steps performed under control signals from the controller using sense inputs from temperature and pressure sensors, the method comprising the steps of: by the compressor, compressing inlet ambient air to a pressure of greater than 1.1 bar to provide a primary flow, at the flash evaporation supersonic nozzle receiving the primary flow to increase speed of the primary flow to be supersonic, by the water supply providing droplets into the primary flow, in the condenser mixing the primary flow with a secondary flow of ambient air and condensing the mixed flow.

[0032] Preferably, the condenser performs said mixing and condensing in along an axis aligned with the nozzle.

[0033] Preferably, where the condenser comprises a condenser tube: the inlet section receives the supersonic primary flow from the nozzle and allows inflow of ambient secondary air caused by suction around the supersonic primary flow so that the primary and secondary flows are mixed, at the mixing throat the mixed air is speeded up to provide a mixed flow and the tube allows condensation of the mixed flow within the volume of the condenser tube, and at the outlet section the mixed flow is diffused flow to provide outlet liquid water and exhaust air with less moisture content than the mixed air.

[0034] In some preferred examples, the method further comprises stabilizing inlet ambient air pressure within the stabilizing chamber between the compressor and the nozzle.

[0035] In some preferred examples, the compressor compresses the inlet ambient air to a pressure in the range of 1.1 bar to 3.0 bar, preferably 1.2 bar to 3.0 bar, and more preferably 1.4 bar to 2.0 bar.

[0036] In some preferred examples, the water supply collects and feeds back a portion of the outlet water.

[0037] In some preferred examples, the water supply heats the water to a temperature in the range of 10°C to 95°C, thereby controlling the rate of flash evaporation.

[0038] In some preferred examples, the heater heats the water to a temperature in the range of 60°C to 90°C.

[0039] In some preferred examples, the water injector provides droplets having a size in the range of 5 pm to 100 pm.

[0040] In some preferred examples, the water supply provides water injection flow by weight to compressed air weight in the range of 1 :500 to 1 : 10,000, preferably 1 :1000 to 1 : 10,000.

[0041] In some preferred examples, the ratio by weight of water supply to the primary flow to compressed air supply to the nozzle is in the range of 1 : 1,000 to 1 : 10,000.

[0042] In some preferred examples, the compressor and the flash evaporation supersonic nozzle provide a primary flow speed into the condenser tube in excess of Mach 1.1, preferably in excess of Mach 1.5.

[0043] In some preferred examples, the condenser reduces the mixed air speed in the mixing throat to a speed which is still in excess of Mach 1.1, preferably in excess of Mach 1.2.

[0044] In some preferred examples, the flash evaporation supersonic nozzle and the compressor provide a temperature reduction in the range of 80°C to 150°C, for example from + 30°C to -90°C at the outlet of said nozzle.

[0045] We also describe an energy system comprising an energy capturing device comprising: an inlet for compressed air at a pressure elevated above atmospheric, a flash evaporation supersonic nozzle arranged to receive the compressed air, a water supply upstream of the flash evaporation nozzle and arranged to provide droplets into the compressed air as it enters the flash evaporation nozzle, wherein the flash evaporation nozzle is arranged to provide a supersonic primary flow, a condenser tube in registry with the flash evaporation nozzle and comprising: an inlet section to receive the primary flow and allow inflow of ambient secondary air caused by suction around the primary flow so that the primary and secondary flows are mixed, a mixing throat to speed up the mixed air and allow condensation of the mixed flow within the volume of the condenser tube, an outlet section to provide outlet liquid water and exhaust air with less moisture content than the mixed air.

[0046] In some preferred examples, the water supply is linked with a tank for receiving the system outlet water. In some preferred examples, the water supply is configured to feed back a portion of the outlet water. In some preferred examples, the system comprises a compressor to provide the compressed air at the inlet. In some preferred examples, the compressor is configured to provide compressed air at a pressure of greater than atmospheric, preferably at least 1.1 bar.

[0047] In some preferred examples, the flash evaporation supersonic nozzle comprises a flared outlet which is located within the condenser tube inlet section. In some preferred examples, the flash evaporation supersonic nozzle comprises an adjustable axial needle to vary outlet air nozzle outlet flowrate. In some preferred examples, the water supply comprises a heater to heat the water.

[0048] In some preferred examples, the heater is adapted to heat the water to a temperature in the range of 10°C to 95°C, preferably in the range of 60°C to 90°C. In some preferred examples, the water injector provides droplets having a size in the range of 5 pm to 100 pm.

[0049] In some preferred examples, the compressor and the flash evaporation supersonic nozzle are configured to provide a primary flow speed in excess of Mach 1.4, preferably in excess of Mach 1.5.

[0050] In some preferred examples, the condenser is configured to reduce the mixed air speed in the mixing throat to a speed in excess of Mach 1.1, preferably in excess of Mach 1.2.

[0051] In some preferred examples, the flash evaporation supersonic nozzle and the compressor are configured to provide a temperature reduction in the range of 80°C to 150°C, for example from + 30°C to -90°C at the outlet of said nozzle.

[0052] In some preferred examples, the water supply is configured to provide water injection flow by weight to compressed air weight in the range of 1 : 1000 to 1 : 10,000. In some preferred examples, the ratio of cross-sectional area of the flash evaporation supersonic nozzle opening to the condenser inlet section is in the range of 1 :20 to 1 :50. In some preferred examples, the increase in cross-sectional area between the condenser tube mixing throat and outlet section is in the range of 200% to 8000%. In some preferred examples, the inlet includes a compressor.

[0053] In some preferred examples, the device is mounted on a rotor arranged to rotate with the inlet leading, and the rotor is mounted to a hub which includes conduits for the outlet water and for injected water for the nozzle. We describe an energy system which very efficiently extracts water from ambient air and can also in some examples provide motive energy in the form of flowing dried air. The system comprises a nozzle which is augmented by supersonic flash evaporation and an ejector type tube specifically configured to promote and capture water vapour condensation. The purpose is to collect condensed water with the assistance of nozzle pre-evaporation. In one case this means water condensation for less power requirement. In a second case this extra power can be directly harnessed by allowing the nozzle / tube to rotate around an axle to drive an electric motor or direct drive.

[0054] Detailed Description of the Invention

[0055] The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:

[0056] Fig. 1(a) is a diagram of an energy system of the invention incorporating a flash evaporation supersonic nozzle and a matching condenser tube, and Fig. 1(b) shows the nozzle in more detail,

[0057] Fig. 2 is a temperature (T)-entropy(S) diagram for the system in operation, and

[0058] Fig. 3 is a diagram illustrating an alternative nozzle.

[0059] Referring to Figs. 1(a) and (b) an energy system 1 of the invention is configured to suck ambient moist air from the surrounding environment and to provide as its output liquid water and a dry air flow providing motive energy. The main function of the energy system 1 is to provide water, and so it finds application particularly in desert regions. It also provides motive energy at its output in the form of dry air under a pressure greater than atmospheric, and this may be used as desired for such things as electricity generation.

[0060] In overview, the systems of the invention convert the latent heat energy of moist air into water and also motive energy in dry exhaust air. It does this by a flash evaporation nozzle receiving a primary flow of compressed air at a pressure of at least 1.1 bar and performing flash evaporation of this air, referred to as supersonic primary air, together with added water droplets. The supersonic speed of the primary flow from the flash evaporation nozzle creates suction to draw in ambient secondary air. A condenser tube with a mixing throat enhances mixing of the primary and secondary air flows and causes condensation within the volume of the tube without need for heat exchanger surfaces, to provide output water and dry air at a pressure higher than atmospheric. This is achieved with only a small input of energy, primarily to the compressor at the inlet.

[0061] The system 1 has a controller 30 linked to components as indicated and described in more detail below. The controller 30 is in the form of digital data processors in a PLC suitably programmed to perform the control functions described below using sensor inputs. The methods of operation of the system 1 are controlled by the controller 30.

[0062] In the following description values are given for an example working system, however the invention is not limited to these values, and we provide a table of ranges for preferred values of parameters of systems of the invention. The system which has been built is of a small scale to produce about 20 litres / hour in Ireland, however for a greater output it may of course be scaled up in a manner known to those skilled in the art to a larger size or multiple such systems may be arranged in parallel. While the system may be scaled up, the parameter ranges for pressures and temperatures are still applicable. For example even in a larger system, the inlet air pressure should still be in the range of 1.1 bar to 3 bar, preferably 1.4 bar to 3 bar.

[0063] The system 1 comprises an ambient air inlet 2 through which air is drawn by a 3 kW compressor 3, which provides a pressure increase to about 1.6 bar and in various ambient conditions the air temperature is increased to a value in the range of 10°C to 35°C.

[0064] This compressed air is directed in a conduit 4 of length 700 mm and diameter 65 mm, which stabilizes the pressure. If required, a pressure chamber may be provided for enhanced pressure stabilization.

[0065] The conduit 4 leads to a flash evaporation nozzle 5 having a water inlet 6 and a choke throat 50. The water is provided at a very small flow rate immediately before, immediately after, or into the throat, the important point being that it is directed into the primary flow. These droplets act as fuel / accelerant for operation of the system.

[0066] There is in the nozzle 5 an axially mounted needle 51 with a tip 52 within a converging section, or choke throat, 56, and there is a flared opening 57 for supersonic primary flow. With linear movement of the needle 51 the annular space immediately upstream of the nozzle flared opening 57 can be varied. There is an actuator 53 for adjustment of the needle 51 longitudinal position to set the extent of reduction of cross-sectional area towards the nozzle opening and hence the fluid parameters.

[0067] The nozzle 5 has the following dimensions in this example.

[0068] Choke throat 56 converging taper angle, 10°.

[0069] Choke throat 56 maximum diameter 65 mm.

[0070] Choke throat 56 exit opening diameter at the flare 57 end, 11 mm.

[0071] Length of the choke throat 56 / 57 45 mm.

[0072] Immediately downstream of the flash evaporation nozzle 5 there is a condenser tube 10 comprising: an inlet section 11 of length 350 mm and internal diameter 65 mm; a mixing throat 12 of 300 mm length and 32 mm diameter; and an outlet section 13 of 300 mm length and 69 mm diameter.

[0073] The condenser tube outlet section 13 provides a flow 15 of condensed water to a tank 20, and there is also a flow of exhaust air.

[0074] A pump 26 draws water from the tank 20 to a feedback line 25 to provide water for the nozzle water inlet 6. This is heated to at least 60 °C to improve effectiveness of water extraction in the components 5 and 10. A major function is that evaporation downstream of the flash evaporation nozzle 5 is encouraged, and heating of the water droplets helps this. The heater 27 is connected to the controller 30, allowing the controller to control the rate of evaporation.

[0075] It should be noted that in conventional supersonic flow systems evaporation is regarded as something to be avoided. However, in the invention it is encouraged by compressing the primary flow, introducing the droplets into the nozzle, and allowing a secondary flow of surrounding air into the condenser tube.

[0076] The controller 30 is linked to components as indicated and described in more detail below, and the main sensors which feed the controller 30 are:

[0077] Pressure and temperature sensors P4 and T4 for the compressor outlet conduit 4.

[0078] Temperature sensors T27 for the water droplet supply 27.

[0079] Feedback water pressure sensors P26 at the pump 26.

[0080] Motion sensors for position of the needle 51. Pressure sensors P57, Pl 1, P12, and P13 for pressure at the nozzle outlet and within the condenser tube 10.

[0081] Also, broken lines show control links from the controller 30 to the compressor 3, the pump 26, and nozzle needle drive, and the spray heater 27.

[0082] The flash evaporation nozzle 5 in one example delivers primary air into the condenser section 11 at a flow rate of 40 litres / s, speed Mach 1.6, and a temperature of -90°C. The pressure at the exit of the nozzle 5 is less than 0.5 bar, this suction drawing in the secondary air, which rises quickly to a speed of about Mach 1. The combination of the injected water droplets by the supply 6 and the suction of the secondary air provides conditions for mixing of the droplets with the primary air and the secondary air along the length of the condenser tube 10. The condenser mixing throat 12 particularly contributes to mixing by helping to maintain a supersonic flow speed. The injected droplets contribute to nucleation sites in the flow through the condenser 10 and the extent of mixing causes comprehensive condensation in the volume of the condenser tube without need for extensive contact with a surface such as a heat exchanger. Nozzle shock is minimized because of the combination of the injected droplets at the start of the flash evaporation nozzle 5 and the condenser 10 configuration, which together prevent a dramatic drop in air speed from the supersonic value of about Mach 1.6.

[0083] In summary, as water flows into the flash evaporation nozzle 5 on the radial supply inlet 6 it forms droplets in addition to the compressed air. These droplets enter the compressed primary flow, which is regarded as a supersonic primary flow from the flash evaporation nozzle 5. This primary flow experiences a major increase in speed to be supersonic, Mach 1.6 in one example. The consequent reduction in pressure to less than 0.5 bar surrounding the primary flow causes the secondary flow of ambient air into the annular space around the primary flow from the choke throat 50 opening. The pressure around the primary flow in one example is less than 0.5 bar and the secondary flow is at room temperature, typically about 20°C.

[0084] Water vapour is ubiquitous, but the amount varies with geo-position and altitude. This means controls of primary flow pressure, droplet size and temperature are important.

[0085] The droplets injected at the inlet 6 are typically less than 100 pm in diameter and at a temperature in excess of 20°C. The droplet size is achieved by a nozzle tip on the end of the water inlet 6. However, it is not essential that there by a nozzle tip, as the compressed air flow can atomize it to the required droplet size. Some of these droplets evaporate in the nozzle 5 and reduce the pressure and increase the velocity. Those droplets that do not evaporate act as nuclei for condensation in the condenser tube 10. This recovers the pressure and generates thrust / work. Even where droplets are relatively large, possibly over 100 pm they can contribute to spreading the evaporation along the length of the condenser tube 10 in a daisy-chain reaction.

[0086] In tests, the system provided a water flow of about 60 L / hr. About two thirds of this is drawn by the pump 26 in the feedback line 25 to provide the water for the nozzle water inlet 6. This provides a net water gain of 20 L / hr in this example system. This water is drawn from humidity in the air.

[0087] The heater 27 brings the water up to a temperature in excess of 20 °C, and preferably in excess of about 60°C, and we have found that this contributes to the extent of flash evaporation.

[0088] The condenser tube 10 works to provide sufficient condensation that there is little supersonic shock. The conventional teaching in the field of ejector nozzles is that moisture should be minimised at the nozzle inlet and that the flow rate should not be increased to levels in the region of Mach 1.6 in order to reduce shock. However, the system deliberately introduces additional moisture and provides a choke throat for providing a very high primary flow rate and temperature drop to about -90°C, at which the air releases water very efficiently, and the system copes with the tendency towards shock conditions by providing the condenser tube 10 with a mixing throat 12. In the art the teaching has been that flash evaporation does provide condensation, but the evaporation followed by condensation effects are separate and enhance each other. Normally, condensation is a liability in supersonic flow, except when it is preceded by evaporation with suitable separation. In the invention the separation / delay of condensation of flow from the nozzle, happening downstream in the tube 10 after mixing of secondary air flow with the primary flow is beneficial because it provides lower energy demand (less power input into the compressor), and higher condensation. In the past the art teaches that a lot of pressure and hence input energy is required for a given amount of water production, for example a 10 bar steam flow from a boiler. In our case a compressor with only a 1.6 bar output is sufficient, because of the controlled evaporation in the nozzle and the tube 10.

[0089] Also, the dry air at the outlet, if it drives a turbine, can provide an amount of electrical power which matches or exceeds the input electrical power to the compressor and the heater. This is because the system extracts latent energy from the water vapour in both the primary and secondary air flows into the system (at the compressor and the secondary air at the nozzle). Essentially, the system uses the ambient air as a fuel source.

[0090] Referring to Fig. 2 the operation of the system 1 may be described in terms of a temperatureentropy relationship, as follows:

[0091] 2, ambient air;

[0092] 2-7-8, compression of the ambient air by the compressor 3 and addition of heat due to the compression;

[0093] 8-1, passage through the conduit 4 which provides pressure stabilization;

[0094] 1-3, isentropic expansion in the nozzle 5 with temperature decrease to about -90°C;

[0095] 3-4, flash evaporation at the choke throat 50 opening;

[0096] 4-5, mixing of the primary and secondary flows in the condenser tube 10, especially the mixing throat 12; and

[0097] 5-6, condensation towards the end of the condenser tube 10, especially the outlet sectionl3.

[0098] Advantageously, the nozzle 5 and its supply system adds in a controlled manner water droplets as the compressed air enters the choke throat 50, thereby enhancing flash evaporation. The droplets may be added to the primary flow in or immediately upstream or downstream of the throat. The condenser 10 downstream of the throat acts as a diffuser to induce condensation to provide a flow of water as an output of the device 1. The system manages both the primary and secondary inlet flows, the flows being to achieve a specific level of condensation to partially slow and repressurise the airflow.

[0099] The system 1 induces the secondary flow as a large multiple of the primary flow, powered by the low-pressure suction afforded by evaporation in the nozzle. This also allows a moisture vapour overload of the already moist air. The condenser 10 tubular configuration facilitates mixing and increased speed to cause enhanced condensation of the moisture, followed by exit from the mixing throat 12 to slow down the air. The outcome is an accelerated but reduced (due to latent heat addition) shock subsonic exit jet.

[0100] The controller 30 provides real time control to optimise operation of the system. One potential problem is that the compressed air in the compressor outlet 4 may have decreased pressure (for example down to below 1.4 bar) and consequent increased temperature (for example up to 70°C). If there is a trend in this direction the controller 30 can increase the flow of coolant air around the compressor. Also, monitoring of the locations immediately downstream of the nozzle 57 is performed. There is a high speed, the primary flow reaching a speed in some examples in the region of 1.6 to 1.8 Mach, and the pressure is consequently low, below 0.5 bar. The controller 30 performs control of the compressor and of the droplet temperature and flow rate to track an isentropic table so that a desired ratio between the inlet pressure of about 1.6 bar and the pressure in the tube 10 of about 0.5 bar is maintained.

[0101] In one example of operation of the system 1 the energy input was 2.2 kW in total for the compressor

[0102] 3 ,the pump 26, and the spray heater 27, while the output was 20 L / hr of clean water.

[0103] In preferred examples the process parameters are: The flash evaporation in the nozzle 5 outlet causes the supersonic exit flow to further accelerate beyond the initial pressure provided by the compressor, thereby allowing lower pressure and more suction. The nozzle 5 and condenser tube 10 allow flow propulsion and the un-flashed droplets are used downstream for condensation collection. The injected droplets are typically less than 100 pm (preferably between 5 pm and 100 pm) in diameter and have a temperature in excess of 20°C. The fact that there is a separate supply of pressurized air (in the conduit 4) and droplets (in the injector 6) allows accurate control of droplet size and temperature so that the desired extent of droplets evaporate in the nozzle 5 exit and reduce the pressure and increase the velocity to target levels. Those droplets that do not evaporate act as nuclei for condensation in the condenser tube 10. This recovers the pressure and generates thrust / work in some examples, and in other examples provides only water.

[0104] The nozzle 5 accelerates the airflow until it reaches the speed of sound, and after this the Mach number continues to increase and the evaporative fluid is discharged, causing the air to cool, which accelerates the ambient flow further and decreases the pressure. On exiting from the condenser tube 10 the lower pressure causes a thrust and suction. Unevaporated droplets cause the water content of the air to condense, releasing latent heat which results in a decrease in Mach number and an increase in pressure. The increased pressure in the outlet section 13 tube will produce a thrust which can be used to generate work. The system has no dependence on wind speed and its energy source is directly derived from the always available ambient moist air.

[0105] It will be appreciated that the condensing fluid is secured before condensation shock occurs in the airflow of the mixing throat 12.

[0106] Further Discussion about operation of the System

[0107] Primary motive flow is generated by the compressor. This flow is decompressed by a nozzle 5 and subsequently this is augmented by flash evaporation. This primes the system. There is then an extra passive air flow intake and the conditions are shared between the two flows in the mixing tube 10. The primary flow is moving in some examples at about Mach 1.8 and drops to Mach 1.3 on mixing. The secondary flow moves from virtually 0 to Mach 1.3 on mixing. The two combined flows now tend towards condensation as they are very cold and the primary flow has had extra water added to it as evaporation. This comes to a head at the end of the mixing throat 12 and the start of the defusing tube section 13. Here, the air tries to go even faster as it goes into a wider space. This would be problematical for dry air, and it would collapse with a large shock. However, with moist air after shedding the droplets in the cold flow it becomes warmer and the shock becomes negligible. This means that the system provides droplets in relatively dry air, the work done on the two (primary and secondary) flows is essentially energized by the condensation acting as a fuel. This means the system increases the total momentum of the primary and secondary air flows, the energy to achieve this being extracted from the moisture in the ingested ambient and secondary air and in the water droplets.

[0108] Fig. 3

[0109] A system of the invention may have a needle in the flash evaporation nozzle downstream from the throat. Referring to Fig. 3 there is in a nozzle 205 with an axially mounted needle 251 on the downstream side of the throat, with a tip 252 facing upstream and within a diverging section of the choke throat 256, and there is a flared opening 257 for supersonic primary flow. The needle has a downstream-facing tip 253 also. With linear movement of the needle 251 the annular space immediately downstream of the nozzle flared opening 257 can be varied. There is an actuator 253 for adjustment of the needle 51 longitudinal position to set the extent of reduction of cross- sectional area from the nozzle opening and hence the fluid parameters.

[0110] The invention benefits from evaporation in the supersonic nozzle, and not just adding droplets into the motive flow but evaporating them in a specific area and manner in the tube 10 to accelerate the flow and increase stagnation pressure. This achieves power and water production.

[0111] For power production, evaporation of the fluid in the supersonic nozzle and subsequent condensation are power producing. In some examples of the invention there is a turbine in the exit tube to absorb the excess kinetic energy of the airflow. Other examples include charged particles in the flow and magnetic fields. Prior systems with supersonic flows require power from outside their device, whereas in the present invention the compressing of inlet air, introduction of water droplets, drawing in of secondary air, and controlled condensation in the condenser tube achieve efficient extraction of the latent energy in the water droplets to provide water from the inlet air and also power in the dry air.

[0112] The cooling effect of the condenser tube centre (mixing section) give a refrigerant effect which may be used by surrounding it with a heat exchanging jacket. This allows direct low temperature gas / liquid heat exchange. This allows the components of a gas / liquid to be cooled cryogenically and separated (air giving liquid oxygen, nitrogen and hydrogen with some CO2 capture. The cooling effect of the condenser tube as a heat exchange source allows for spot cooling / air conditioning and refrigeration / freezer applications.

[0113] In other examples a device is configured to fit in the trailing edge of a wing / turbine blade augmenting the flow, thrust and power. The airflow is the Coanda effect over the wing propelled by the nozzle at the trailing edge.

[0114] Components of embodiments can be employed in other embodiments in a manner as would be understood by a person of ordinary skill in the art. The invention is not limited to the embodiments described but may be varied in construction and detail. For example the condenser described is in the form of a tube aligned with the nozzle, and the secondary air is drawn in around the primary flow. However it is envisaged that the condenser sections may not be on the longitudinal axis of the nozzle, and indeed the secondary air may be pumped into the primary flow. However the arrangement described is simpler and more effective.

Claims

Claims1. An energy system comprising an energy capturing device comprising: a controller (30) linked to sensors and configured to perform control of the system using sensor inputs, an inlet (2) for ambient air, a compressor (3) configured to compress the inlet ambient air to a pressure of greater than 1.1 bar to provide a primary flow, a flash evaporation supersonic nozzle (5) arranged to receive the primary flow to increase speed for the primary flow to be supersonic, a water supply (6) arranged to provide water droplets into the primary flow, and a condenser tube (10) comprising: an inlet section (11) to receive the supersonic primary flow from the nozzle and to allow inflow of ambient secondary air caused by suction around the supersonic primary flow so that the primary and secondary flows are mixed, a mixing throat (12) configured to speed up the mixed air to provide a mixed flow and allow condensation of the mixed flow within the volume of the condenser tube, and an outlet diffuser section (13) to provide outlet liquid water and exhaust air2. An energy system as claimed in claim 1, further comprising a pressure stabilizing chamber (4) between the compressor (3) and the nozzle (5).

3. An energy system as claimed in claim 1 or claim 2, wherein the compressor is configured to compress the inlet ambient air to a pressure in the range of 1.1 bar to 3.0 bar, preferably 1.2 bar to 3.0 bar, and more preferably 1.4 bar to 2.0 bar.

4. An energy system as claimed in any preceding claim, wherein the water supply (26, 6) is configured to collect and feed back a portion of the outlet water (15).

5. An energy system as claimed in any preceding claim, wherein the water supply (25, 26, 6) comprises a heater to heat (27) the water.

6. An energy system as claimed in claim 5, wherein the heater is adapted to heat the water to a temperature in the range of 10°C to 95°C, thereby controlling the rate of flash evaporation.

7. An energy system as claimed in claim 6, wherein the heater is adapted to heat the water to a temperature in the range of 60°C to 90°C.

8. An energy system as claimed in any preceding claim, wherein the water injector provides droplets having a size in the range of 5 pm to 100 pm.

9. An energy system as claimed in any preceding claim, wherein the water supply is configured to provide water injection flow by weight to compressed air weight in the range of 1 :500 to 1 : 10,000, preferably 1 : 1000 to 1 :10,000.

10. An energy system as claimed in any preceding claim, wherein the ratio by weight of water supply to the primary flow to compressed air supply to the nozzle is in the range of 1 : 1,000 to 1 :10,000.

11. An energy system as claimed in any preceding claim, wherein the flash evaporation supersonic nozzle comprises a flared outlet (57).

12. An energy system as claimed in claim 11, wherein the flared outlet (57)is located within the condenser tube inlet section (11).

13. An energy system as claimed in any preceding claim, wherein the flash evaporation supersonic nozzle comprises an adjustable axial needle (51, 52, 251) to vary outlet air nozzle outlet flowrate.

14. An energy system as claimed in any preceding claim, wherein the compressor and the flash evaporation supersonic nozzle are configured to provide a primary flow speed into the condenser tube in excess of Mach 1.1, preferably in excess of Mach 1.5.

15. An energy system as claimed in claim 12, wherein the condenser is configured to reduce the mixed air speed in the mixing throat to a speed which is still in excess of Mach 1.1, preferably in excess of Mach 1.2.

16. An energy system as claimed in any preceding claim, wherein the flash evaporation supersonic nozzle and the compressor are configured to provide a temperature reduction in the range of 80°C to 150°C, for example from + 30°C to -90°C at the outlet of said nozzle.

17. An energy system as claimed in any preceding claim, wherein the ratio of cross-sectional area of the flash evaporation supersonic nozzle (5) opening to the condenser inlet section is in the range of 1 :20 to 1 : 100, preferably 1 :20 to 1 :50.

18. An energy system as claimed in any preceding claim, wherein the decrease in cross- sectional area between the condenser tube inlet (11) and the mixing throat (12) is in the range of 10% to 50%.

19. An energy system as claimed in any preceding claim, wherein the increase in cross- sectional area between the condenser tube mixing throat (12) and the outlet section (13) is in the range of 200% to 8000%.

20. A method for producing water, the method performed by an energy system of any preceding claim, the method comprising steps performed under control signals from the controller (30) using sense inputs from temperature and pressure sensors (T4, T27, P4, Pl 1, P12, P13), the method comprising the steps of by the compressor (3), compressing inlet ambient air to a pressure of greater than 1.1 bar to provide a primary flow, at the flash evaporation supersonic nozzle (5) receiving the primary flow to increase speed of the primary flow to be supersonic, by the water supply (6) providing droplets into the primary flow, at the condenser tube (10): the inlet section (11) receiving the supersonic primary flow from the nozzle and allowing inflow of ambient secondary air caused by suction around the supersonic primary flow so that the primary and secondary flows are mixed, at the mixing throat (12) speeding up the mixed air to provide a mixed flow and allowing condensation of the mixed flow within the volume of the condenser tube, and at the outlet section (13) diffusing the flow to provide outlet liquid water and exhaust air with less moisture content than the mixed air.

21. A method as claimed in claim 20, further comprising stabilizing inlet ambient air pressure within the stabilizing chamber (4) between the compressor (3) and the nozzle (5).

22. A method as claimed in claim 20 or claim 21, wherein the compressor compresses the inlet ambient air to a pressure in the range of 1.1 bar to 3.0 bar, preferably 1.2 bar to 3.0 bar, and more preferably 1.4 bar to 2.0 bar.

23. A method as claimed in any of claims 20 to 22, wherein the water supply (26, 6) collects and feeds back a portion of the outlet water (15).

24. A method as claimed in any of claims 20 to 23, wherein the water supply heats the water to a temperature in the range of 10°C to 95°C, thereby controlling the rate of flash evaporation.

25. A method as claimed in claim 24, wherein the heater heats the water to a temperature in the range of 60°C to 90°C.

26. A method as claimed in any of claims 20 to 25, wherein the water injector provides droplets having a size in the range of 5 pm to 100 pm.

27. A method as claimed in any of claims 20 to 26, wherein the water supply provides water injection flow by weight to compressed air weight in the range of 1 :500 to 1 : 10,000, preferably 1 : 1000 to 1 : 10,000.

28. A method as claimed in any of claims 20 to 27, wherein the ratio by weight of water supply to the primary flow to compressed air supply to the nozzle is in the range of 1 :1,000 to 1 : 10,000.

29. A method as claimed in any of claims 20 to 28, wherein the compressor and the flash evaporation supersonic nozzle provide a primary flow speed into the condenser tube in excess of Mach 1.1, preferably in excess of Mach 1.5.

30. A method as claimed in claim 29, wherein the condenser reduces the mixed air speed in the mixing throat to a speed which is still in excess of Mach 1.1, preferably in excess of Mach 1.

2.

31. A method as claimed in any of claims 20 to 30, wherein the flash evaporation supersonic nozzle and the compressor provide a temperature reduction in the range of 80°C to 150°C, for example from + 30°C to -90°C at the outlet of said nozzle.

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