Equipment and methods for extracting water from humid ambient air

Abstract

An apparatus for extracting water from humid ambient air, the apparatus (1) comprising a conduit (2) having in sequence: a compressor (3) for compressing humid ambient air into compressed ambient air, a first condenser (5) for drying the compressed ambient air into dry compressed air, an expansion valve or expander (7) for expanding the dry compressed air into dry expanded air, and a second condenser (8), characterized in that the first condenser (5) is further configured to guide humid ambient air as a coolant through it to extract water from the compressed ambient air in a first stage through an outlet (12), and the second condenser (8) is configured to guide dry expanded air as a coolant through it to extract water from the humid ambient air in a second stage through an outlet (15).

Description

Technical Field

[0001] This invention relates to an apparatus for extracting water from humid ambient air.

[0002] More specifically, the present invention aims to generate drinking water using ambient air. Background Technology

[0003] Equipment for producing drinking water is known, such as water purification equipment or seawater desalination equipment.

[0004] The drawback of this known device is that it requires impure liquid water for this purpose.

[0005] Atmospheric water generators are also well-known; they require energy and humid ambient air to produce brine and / or drinking water.

[0006] The advantage of this is that this generator can be used in places with very little or no impure liquid water.

[0007] Known passive systems do not require external electrical or mechanical energy.

[0008] The downside is that they require a large space and surface area, making them unsuitable for large-scale water production.

[0009] Active systems are also known to utilize electrical or mechanical energy to generate cooling capacity to cool ambient air below the dew point.

[0010] Such systems use cooling circuits that contain coolants or refrigerants (such as fluorocarbons).

[0011] The efficiency of this cooling circuit decreases sharply when the difference between ambient temperature and cooling temperature increases.

[0012] Therefore, in environments with high ambient temperature, low humidity, and consequently low dew point, such systems are relatively inefficient.

[0013] In addition, the liquid coolants used are often harmful to the environment. Summary of the Invention

[0014] The present invention aims to provide a solution to at least one of the above-mentioned disadvantages and other disadvantages.

[0015] The object of the present invention is an apparatus for extracting water from humid ambient air according to claim 1 and a method for extracting water from humid ambient air according to claim 9.

[0016] In other words, the equipment includes piping, which sequentially includes: a compressor with an inlet for humid ambient air, a primary section of a first condenser, an expander, and a secondary section of a second condenser. The secondary section of the first condenser is configured to guide humid ambient air as a coolant through it, and the primary section of the second condenser is configured to guide humid ambient air to be dried through it.

[0017] In this device, water is generated in two locations: the first stage and the second stage. The air drawn in and compressed by the compressor is cooled by ambient air in the first condenser, thus separating the water. This is feasible because the ambient air temperature also increases with the compression, along with the pressure. Therefore, the compressed ambient air is warmer than the uncompressed ambient air. This uncompressed ambient air can then be used as a coolant to cool the compressed ambient air. Cooling continues until the dew point is reached to extract water from the compressed ambient air in the first stage. The compressed ambient air is then dried into dry compressed air.

[0018] Therefore, it should also be understood that no phase change preferably occurs during the compression of air in a humid environment.

[0019] In the next step, the dry compressed air is expanded into dry expanded air. Due to the expansion, the temperature will decrease again, meaning the temperature of the expanded air will be lower than that of the dry compressed air.

[0020] After expansion, the dry expanded air is then used as cooling air or coolant in the second condenser, thereby separating water from the still humid ambient air flowing through the second condenser.

[0021] The advantage is that it does not require harmful liquid coolants, but instead uses ambient air for cooling. Therefore, the device is safer for people and the environment.

[0022] Another advantage is that even at high ambient temperatures, the performance or efficiency of this device is comparable to known devices, but the proposed solution is cheaper and therefore more economically attractive.

[0023] Another advantage is that this equipment is very simple and inexpensive to produce. Furthermore, the cost per unit of water produced is also low.

[0024] This is partly because it does not involve harmful liquid coolants with strict safety requirements, and partly because the equipment does not contain a closed-loop circulation system.

[0025] According to one embodiment, the inlet pipe is connected to the inlet of the primary section of the second condenser, and the inlet pipe includes the primary section of the first heat exchanger; the outlet of the primary section of the second condenser is connected to the inlet of the secondary section of the first heat exchanger through the first pipe, and the outlet of the secondary section of the second condenser is connected to the inlet of the secondary section of the first heat exchanger through the second pipe.

[0026] According to one embodiment, the secondary portion of the second heat exchanger is included in the second pipeline, and the primary portion of the second heat exchanger is included in the inlet pipeline and located between the primary portion of the first heat exchanger and the primary portion of the second condenser.

[0027] According to one embodiment, the expander is equipped with a generator for generating energy, which is connected to the drive unit of the compressor to supply energy to it. Attached Figure Description

[0028] To better illustrate the features of the invention, some preferred embodiments of the apparatus and method for extracting water from humid ambient air according to the invention are described below by way of non-limiting example with reference to the accompanying drawings, wherein:

[0029] Figure 1 The device according to the invention is shown schematically;

[0030] Figure 2 It shows Figure 1 Variations;

[0031] Figure 3 Meteorological data for humid ambient air are shown;

[0032] Figure 4 The total water production and system pressure in the method are shown;

[0033] Figure 5 The water production rates of the first and second condensers in the method are shown.

[0034] Figure 6 A simplified pT diagram of the method is shown. Detailed Implementation

[0035] Figure 1 The apparatus for generating water according to the present invention, schematically shown in the diagram, includes a pipe 2, in which the following elements are sequentially included:

[0036] Compressor 3, having an inlet 4 for humid ambient air;

[0037] The primary section 6 of the first condenser 5;

[0038] Expander 7;

[0039] Secondary part 9 of the second condenser 8.

[0040] In this example, compressor 3 is an oil-free compressor, but it is not mandatory. The advantage of doing so is that there is ultimately no oil in the air, and the condensate is also separated from the air.

[0041] The secondary part 10 of the first condenser 5 is configured to guide humid ambient air, which is the coolant, through it.

[0042] Therefore, in this example, but not essential to the invention, a fan, such as a first fan 11, is provided.

[0043] In addition, the first condenser 5 is equipped with a discharge device 12 for discharging the condensate formed in the primary section in the first stage to extract water from the humid ambient air.

[0044] The primary section 13 of the second condenser 8 is configured to guide the passage of humid ambient air to be dried.

[0045] This means that the dry, expanded air will be used as the cooling air in the second condenser 8.

[0046] To guide the humid ambient air to be dried through the primary section 13 of the second condenser 8, a second fan, in this example fan 14, is provided. The second fan 14 is not essential to this invention.

[0047] Therefore, both the first fan 11 and the second fan 14 can be replaced, for example, with a blower or any other type of machine configured to generate flow. The first fan 13 and the second fan 14 can also include the same mechanical device and achieve flow in the first condenser 5 and the second condenser 8 through a set of guides.

[0048] Like the first condenser 5, the second condenser 8 has a discharge device 15 for discharging the condensate formed in the primary section 13 in the second stage to extract water from the humid ambient air.

[0049] In this example, but not necessarily, the inlet pipe 17 is connected to the inlet 16 of the primary section 13 of the second condenser 8, which contains the primary section 19 of the first heat exchanger 18.

[0050] The outlet 20 of the primary section 13 of the second condenser 8 is connected to the inlet 21 of the secondary section 22 of the heat exchanger 18 via the first pipe 23.

[0051] The outlet 24 of the secondary section 9 of the second condenser 8 is also connected to the inlet 21 of the secondary section 11 of the heat exchanger 18 via the second pipe 25.

[0052] The operation of device 1 is as follows.

[0053] Compressor 3 draws in and compresses humid ambient air, causing it to heat up.

[0054] Then, the warm, humid compressed air passes through the primary section 6 of the first condenser 5, where it is cooled to the dew point by the ambient air using the first fan 11.

[0055] Here, condensate, i.e., water, will form and be removed from device 1 through outlet 12. This is the first node or first stage for producing or generating water.

[0056] The dry air is then expanded by an expander or expansion valve 7 and further cooled by the expansion.

[0057] The temperature of the expanded air is lower than that of the ambient air, and the expanded air is guided through the secondary part 9 of the second condenser 8 to cool the humid ambient air below the dew point.

[0058] The humid ambient air is guided through the primary section 13 of the second condenser 8, where it first passes through the primary section 19 of the heat exchanger 18. For this purpose, a second fan 14 will be used here.

[0059] When humid ambient air is cooled in the second condenser 8, condensate will form at the second node or second stage and will be discharged from the device 1 through outlet 15. This is the second node that produces or generates water.

[0060] The temperatures of the expanded air flowing out of the secondary section 9 of the second condenser 8 and the dry air flowing out of the primary section 13 of the second condenser 8 are both approximately at the ambient air dew point.

[0061] These two gases are guided to the secondary section 22 of the heat exchanger 18 through the first pipe 23 and the second pipe 25.

[0062] Here, the humid ambient air has already undergone its first cooling process before being cooled to the dew point in the second condenser 8.

[0063] The air used for cooling in the first condenser 6 and heat exchanger 18 is then simply discharged into the atmosphere.

[0064] Figure 2 An alternative arrangement is shown in the figure.

[0065] Here, the expander 7 is equipped with a generator 26 for generating energy.

[0066] The generator 26 will be driven by the expander 7 during the expansion process in order to recover energy from the expansion process.

[0067] The generator 26 is connected to the drive unit 27 of the compressor 3 to supply it with energy, whether partially or not. The generator's remaining energy needs can then be met by solar panels. Furthermore, the generator can also provide energy to the first ventilator 11 and / or the second ventilator 14.

[0068] In this way, the energy generated during the expansion process is optimally recovered.

[0069] Of course, it is also possible that generator 26 supplies the generated energy to the power grid.

[0070] also, Figure 2 A second heat exchanger 28 is also provided.

[0071] The secondary section 29 of the second heat exchanger 28 is included in the second pipeline 25, wherein the primary section 30 of the second heat exchanger 28 is included in the inlet pipeline 17 and is located between the primary section 19 of the first heat exchanger 18 and the primary section 13 of the second condenser 8.

[0072] In this way, the humid ambient air guided to the second condenser 8 through the inlet pipe 17 will be cooled for the first time in the first heat exchanger 18 and then further cooled in the second heat exchanger 28.

[0073] The expanding gas entering the second pipe 25 from the secondary section 9 of the second condenser 8 will first be cooled in the second heat exchanger 28, and then in the first heat exchanger 18.

[0074] Of course, two or more of these heat exchangers 18 and 28 can also be provided.

[0075] The operation of device 1 is still similar Figure 1 Device 1 is shown.

[0076] The following uses, for example Figures 3 to 6 The process parameters of the method shown further illustrate the features of the present invention.

[0077] Figure 3 The graph shows the temperature (34) and relative humidity (35) of the air in a humid environment over three consecutive 24-hour periods (31, 32, 33). The horizontal axis (3) shows the hours (36) for each consecutive 24-hour period starting at midnight (37). Figure 4 and Figure 5 In the diagram, the same horizontal axis is plotted corresponding to the relationships between other operational parameters that illustrate the method.

[0078] Temperature 34 begins to drop from time 37 to a minimum of 38, where it remains for a period of time. Afterward, the temperature rises to a maximum of 40 at time 39, and then decreases again at time 41.

[0079] like Figure 3 As shown, temperature follows a certain cyclical pattern of increase and decrease, and it should be understood that each 24-hour period is unique. Furthermore, this pattern depends on geographical location and climatic period.

[0080] also, Figure 3 The relative humidity of the ambient air at 35 is shown in a similar manner to that at temperature 34. A repeating pattern can also be observed here, which also depends on geographical location and climatic period.

[0081] Figure 4 The total water production 42 and maximum system pressure 43 during the method for extracting water from humid ambient air according to an embodiment of the present invention are further illustrated. It should also be noted that... Figure 4 The water production rate 42 and the maximum system pressure 43 shown are related to Figure 3 The meteorological data shown is relevant. It should be noted that, as mentioned earlier, Figure 3 The 24 hours shown on the horizontal axis correspond to Figure 4 Twenty-four hours on the central horizontal axis.

[0082] from Figure 4 The diagram shows that there is an approximately linear relationship between water production 42 and maximum system pressure 43 at roughly the same time points.

[0083] exist Figure 5 The water production is further divided based on the first condenser 5 (curve 44) and the second condenser 8 (curve 45).

[0084] exist Figure 6 The diagram shows a pT graph, which represents, for example,... Figures 3 to 5 The graph illustrates a method for extracting water from humid ambient air. It shows the different states at each time point within the first 24 hours (31 hours). Dashed lines correspond to six hours, thick lines to twelve hours, and normal lines to eighteen hours. Figure 6 The indicated number in corresponds to, for example, Figure 1 The parts in the device according to the invention have the same reference numerals. That is, Figure 6 The number 8 in the middle represents Figure 1 The situation of the second condenser 8.

[0085] Finally, the method will be explained using equations that express the working parameters.

[0086] Environmental conditions, especially absolute humidity, can be expressed as relative humidity (RH). amb Environmental pressure p amb and ambient temperature T amb Functions:

[0087] Total absolute humidity = f(RH) amb ,p amb ,T amb )

[0088] (Equation 1)

[0089] The output temperature T2 of compressor 3 is therefore also the input temperature of the first condenser 5:

[0090] T2 = T amb ×(p2 / p amb )^((k-1) / k)

[0091] (Equation 2)

[0092] Where p2 is the output pressure of compressor 3, and k is the compression modulus.

[0093] Nude T-shirt dew_2 The temperature at which condensation occurs is:

[0094] T dew_2 =T3=f(RH2,p2)

[0095] (Equation 3)

[0096] RH2 refers to the relative humidity after compressor 3.

[0097] The temperature T of the air in condenser 5 2_空气 for:

[0098] T 2_空气 =T amb +ΔT 贡献_冷凝器

[0099] (Equation 4)

[0100] Among them, T 2_空气 ≤T dew_2 .

[0101] The relative humidity RH2 and free water content (free water 2) in compressed air are as follows:

[0102] RH2 = f(total absolute humidity, p2, T) 2_空气 )

[0103] (Equation 5)

[0104] Free water 2 = f(RH2,p2,T) 2_空气 )

[0105] (Equation 6)

[0106] The amount of water m extracted from the compressed air in condenser 5 水_冷凝器 Then it is:

[0107] m 水_冷凝器 =m 空气 ×(Free water 2 / (1+Total absolute humidity))

[0108] (Equation 7)

[0109] The total amount of air is m 空气 .

[0110] The power P required for the first condenser 5 is:

[0111] P = m 空气 ×cp空气 ×(T2–T3)+m 水_冷凝器 ×r 冷凝

[0112] (Equation 8)

[0113] The pressure p3 at expander 7, which is the output of the first condenser 5, is:

[0114] p3≈p2

[0115] (Equation 9)

[0116] The pressure p4 and temperature T4 at the output of expander 7 are:

[0117] p4≈p 环境

[0118] (Equation 10)

[0119] T4 = T3 × (p4 / p3)^((k-1) / k)

[0120] (Equation 11)

[0121] The temperature T in the second condenser 8 dew_4 The dew point is the same as that of ambient air, which is:

[0122] T dew_4 =T 4_空气 =f(RH4, p4)

[0123] (Equation 12)

[0124] Among them, T 4_空气 ≥T4+ΔT 贡献_冷凝器4 .

[0125] The relative humidity RH4 and free water content RH4 of the ambient air directed to the second condenser 8 are as follows:

[0126] RH4 = f(total absolute humidity, p4, T) 4_空气 ),

[0127] (Equation 13)

[0128] Free water 4 = f(RH4, p4, T) 4_空气 )

[0129] (Equation 14)

[0130] The amount of water extracted from the ambient air in the second condenser 8 (m) 水_冷凝器 Then it is:

[0131] m 水_冷凝器 =m 空气_4 ×(Free water 4 / (1+Total absolute humidity))

[0132] (Equation 15)

[0133] The power P required for the second condenser 8 is:

[0134] P = m 空气 ×cp 空气 ×(T amb –T4)=m 水_冷凝器 ×r 冷凝 +m 空气_4 ×cp 空气 ×(T amb –T4)

[0135] (Equation 16)

[0136] For mild maritime climates, such as Belgium, the following figures are given as examples:

[0137] p amb =1 bar;

[0138] T amb ≈2–12℃;

[0139] RH amb ≈70–100%;

[0140] p2≈2–3.5 bar;

[0141] T2≈60–130℃;

[0142] p3≈2–3.5 bar (before expander 7);

[0143] T3≈10–26℃ (before expander 7);

[0144] RH4≈40% (after expander 7);

[0145] p4≈1 bar (after expander 7);

[0146] T4 ≈ -60 to -35℃;

[0147] T5≈-5℃ (dry air after condenser 9).

[0148] The total water production capacity of the first condenser 5 is 0-5 liters / hour, and the total water production capacity of the second condenser 8 is 40-50 liters / hour.

[0149] The present invention is not limited to the embodiments described by way of example and shown in the figures. The apparatus and method for extracting water from humid ambient air according to the present invention can be implemented in various variations without departing from the scope of the present invention.

Claims

1. An apparatus for extracting water from humid ambient air, the apparatus (1) comprising a conduit (2) having, in sequence: a compressor (3) for compressing a first stream of humid ambient air into compressed ambient air; a first condenser (5) for drying the compressed ambient air from the compressor into dry compressed air; an expansion valve or expander (7) for expanding the dry compressed air from the first condenser into dry expanded air; and a second condenser (8). Its features are, The first condenser (5) is also configured to guide a second stream of humid ambient air as a coolant through it to extract water from the compressed ambient air in a first stage including the first condenser through the outlet (12) of the first condenser, and the second condenser (8) is configured to guide dry expanded air from an expansion valve or expander as a coolant through it to extract water from a third stream of humid ambient air introduced into the second condenser in a second stage including the second condenser through the outlet (15) of the second condenser, wherein the piping comprising the compressor, the first condenser, the expansion valve or expander, and the second condenser in sequence does not contain a closed loop.

2. The device according to claim 1 further includes a fan configured to generate a second stream of humid ambient air through the first condenser (5) and / or a third stream of humid ambient air through the second condenser (8).

3. The device according to claim 2, further comprising a first heat exchanger (18) configured to exchange heat between: On the one hand, there is the dry, expanded air after the second condenser (8) and / or the third stream of humid ambient air after water extraction in the second stage; On the other hand, there is a third stream of humid ambient air before water is extracted in the second stage.

4. The device according to claim 3 further includes a second heat exchanger (28) configured to exchange heat between: On the one hand, there is dry, expanded air after the second condenser (8) and before the first heat exchanger (18); On the other hand, there is a third stream of humid ambient air before the second condenser (8) and after the first heat exchanger (18).

5. The device according to claim 4, wherein, The fan is also configured to generate a third stream of humid ambient air through the first heat exchanger (18) and / or the second heat exchanger (28).

6. The device according to any one of the preceding claims further includes a generator (26) connected to an expansion valve or expander (7) and configured to generate energy during the expansion of dry compressed air.

7. The device according to claim 6, wherein, The generator (26) is connected to the drive unit (27) of the compressor (3).

8. The device according to claim 1, characterized in that, The compressor (3) is an oil-free compressor.

9. A method for extracting water from humid ambient air using the apparatus according to any one of claims 1-8, the method comprising the steps of: The first stream of humid ambient air is compressed into compressed ambient air; and Drying compressed ambient air into dry compressed air; and Dry compressed air is expanded into dry expanded air; The method is characterized by further comprising the following steps: The compressed ambient air is cooled by a second stream of humid ambient air to extract water from the compressed ambient air in the first stage; and The third stream of humid ambient air is cooled by drying and expanding air in order to extract water from the third stream of humid ambient air in the second stage.

10. The method of claim 9, further comprising the step of: Heat exchange occurs between the following two: On the one hand, it is the combination of dry, expanded air and the third stream of humid ambient air after water extraction in the second stage; On the other hand, there is the third stream of humid ambient air before water is extracted in the second stage.

11. The method according to claim 10, wherein, Heat exchange also includes: Heat exchange between the following two: On one hand, there is dry, expanding air; On the other hand, there is a third type of humid ambient air.

12. The method according to any one of claims 9 to 11, wherein, The pressure of compressed ambient air depends on the relative humidity of the first gust of moist ambient air.

13. The method according to any one of claims 9 to 11, wherein, The pressure of dry, expanding air is greater than the pressure of the third stream of humid ambient air.

14. The method according to any one of claims 9 to 11, further comprising the following step: A fan is controlled to cool compressed ambient air, a second stream of humid ambient air, and / or a third stream of humid ambient air, wherein the fan speed depends on the temperature of the second and / or third streams of humid ambient air and the dew point of the second and / or third streams of humid ambient air.

Images