RU2190810C2 - Solar power plant - Google Patents

Abstract

FIELD: utilization of solar energy; solar power plants, solar radiation concentrators for parallel operation with heat sources for domestic and technological purposes; joint operation with salt water distilling plants. SUBSTANCE: solar power plant includes semi- cylindrical solar energy concentrators, tubular boilers which are heat- insulated at the top and on sides, supports, monorails; according to invention, concentrators and monorails are located in mutually perpendicular directions, mainly in "North-South" direction-concentrators, "West-East" - monorails; monorails are mounted at the top of supports whose height is approximately equal to radius of semi-cylinders; tubular boilers are located at the top of monorails by means of rolling units; their length slightly exceeds length of concentrators; they are shifted towards North in northern hemisphere and towards South in southern hemisphere; they are located at distances equal to width of concentrators and are joined by hot and cold water pipes; is connected with programmed drive by means of ropes. EFFECT: maximum utilization of solar heat. 3 dwg

Description

 The invention relates to the field of solar power plants with solar concentrators and can be used in industries where low-temperature thermal energy is required. The installation can work in parallel with heat sources for domestic and technological purposes, providing a reduction in energy consumption. Such sources are boiler houses, boiler rooms, baths, laundries, sources of chemical and canning plants, installations for heating air, gas, etc. In the daytime during the warm season, in sunny weather, the proposed installation takes on part of the heat load or the entire load, the rest of the time the main heat producer.

 But the installation becomes particularly attractive when working together with installations for desalination of sea water. This is due to the fact that the accumulation of generated heat and other types of energy is a difficult problem, while the accumulation of fresh water, necessary due to the frequency of operation of the proposed installation, requires only additional tanks for the duration of the downtime of the proposed installation. In the case of a lack of tanks or the need for a more complete desalination plant, a traditional heat source can also be used.

 Famous solar power plants with concentrating systems (see. "Bulletin of inventions" N 26 from 07.15.84. Application N 4379331 / 24-06. RR Aparisi, DI Teplyakov, VG Khantsis, "Solar power plant "F 24 J 3/02: Bulletin of inventions" N 26 from 09.20.95, application N 9302611 3/06. Tveryanovich E.V. "Solar installation". F 24 J 2/18).

 Of the known installations, the closest in technological essence is a solar power station according to the application N 3479331 / 24-06, adopted as a prototype. The power plant has a spherical-shaped solar concentrator with a central hole and a movable solar radiation receiver oriented by the longitudinal axis to the center of curvature of the latter, fixed by a moving mechanism to a support passing through the central hole. The solar concentrator is made integral in the form of long-focus annular strips, the movement mechanism is in the form of a bridge mounted on the support radially to it with a trolley moving along the last one, and the solar radiation receiver is equipped with a solar sensor electrically connected to the moving mechanism and pivotally mounted on the trolley.

 The disadvantage of this device is the complexity of the technical solution, which leads to cost overruns during construction and operation. Here, individual control of each device is required, and in a serious system there can be several hundreds or even thousands of them. In addition, the node of the mobile connection of each device with the energy consumer is complex.

 Known solar installation according to the application N 9302611 3/06 contains a sun-oriented concentrating solar radiation system having primary concentrators focusing the radiation into point foci and secondary reflectors having common foci with primary concentrators made in the form of bodies of revolution around their symmetry axes and directing radiation to a common receiver. Primary concentrators are capable of synchronous rotation around their foci, and secondary reflectors are fixed, made in the form of paraboloids or hyperboloids, the axis of symmetry of which are directed to the receiver.

The disadvantage of this application is the need to rotate the hubs. These are bulky devices, and since they are rotatable, increased demands are placed on their strength, which leads to cost overruns. Their main drawback is high windage. It also places particular demands on structural strength. The increased costs for one solar installation can be justified if it is capable of producing steam with technical parameters for the electric power industry (500-550 ^o С) or heat for high-temperature heat power systems (above 1000 ^o С), while for low-temperature heat power systems the costs should be minimal.

 The device adopted for the prototype has an unusual hub - concentrically located sections of the spheres. But unusualness does not mean simplicity. For low-temperature power systems, if boilers are used in this device instead of solar panels, the concentrators and the device as a whole are unnecessarily complicated. An analogue having bulky mobile concentrators with high windage is economically simply uncompetitive with the proposed installation.

 A solar power installation is proposed that comprises semi-cylindrical solar radiation concentrators, tubular boilers, supports, monorails, a program drive, thermally insulated from above and from the sides, characterized in that the concentrators and monorails are located in mutually perpendicular directions, mainly in the north-south direction - concentrators, "west-east" - monorails, monorails are installed on top of supports, the height of supports is chosen approximately equal to the radius of half cylinders, tubular boilers using rolling devices once placed at the top of the monorails, made with a length slightly greater than the length of the concentrators on the sides of both ends, shifted towards the north in the northern hemisphere, to the south in the southern hemisphere, are located at a distance equal to the width of the concentrators, combined by pipes of hot and cold water , and the entire rigid system of tubular boilers and connecting pipes with the help of movement cables in the forward and reverse directions is connected to the program drive.

 The proposed installation allows you to spend on low-temperature heat, the production of which (hot water and steam with low parameters) is required on a large scale, the minimum possible amount of funds and materials. The concentrator is selected with a one-dimensional concentration (circular half cylinder), with a concentration coefficient of 100-120, and this is quite enough for the production of steam with low parameters. The circular semicylinder, most importantly, allows concentration to be carried out, remaining motionless when the sun moves, which significantly reduces its cost and makes it possible to place it horizontally on the ground, which creates minimal windage. The energy receiver is a tubular boiler, and for any boilers, pipes connecting them are required, so that the cost of the "boiler-pipe" system is even greater than the cost of tubular boilers. Combining pipes of hot and cold water are required in the proposed installation in a minimum quantity, and the entire system of pipes and tubular boilers, raised to the height of the supports, has a slight windage. Finally, the selected types of concentrators and boilers, rigidly connected by pipes, allow using only one-dimensional movement of power receivers and one program drive for the entire system of installations, rather than an individual drive for each concentrator and boiler.

To explain the proposed solar power plant, the drawings are:
Figure 1 - experimental setup for characterizing "the reflected signal in the horizontal plane passing through the center of curvature of the circular cylinder". The following notation was used at the installation: H - height of the characteristic in this plane; L / 2 - half the length of the characteristic, for example, from 12.00 to 16.30; B is the distance of a possible approach of the characteristic south beyond the reflection point (Fig. 2a) when working in the early morning and late evening hours; R is the radius of the circular semicylinder; NS is the north-south direction.

Figa - characteristics of the reflected signal for points a and b located on the line "north-south":
21 is a characteristic taken in the area of June 21;
22 is a characteristic taken in the area of September 21.

 All figure 2 is a bottom view.

 Fig.2b - characteristic of the reflected signal for points a and b located on the line "west-east", taken in the area of June 21.

 Figv is a characteristic for three parallel lines av, cd, ef, taken in the region of June 21.

 FIG. 3 is a drawing of a solar power plant in a perspective view.

The numbers in figure 3 denote:
1 - semi-cylindrical hubs;
2 - tubular boilers, thermally insulated from above and from the sides;
3 - a pipe insulated from all sides, uniting tubular boilers from the cold side;
4 - pipe insulated from all sides, combining tubular boilers from the hot side;
5 - nuts regulating the position of tubular boilers;
6 - supports;
7 - monorails;
8 - intercentric roads;
9 - a flexible pipeline;
10 - heat receiver (desalination plant of salt water);
11 - cables for moving tubular boilers;
12 - gear;
13 - electric motor;
14 is a software device.

If the heat receiver is a desalination plant operating by the distillation method, its inputs and outputs are indicated:
15 - input of the heat exchanger of the desalination plant, through which the steam-water mixture from the "hot" pipe of the solar power plant is supplied;
16 - heat exchanger outlet connected by a pump to the cold pipe of a solar power plant;
17 - salt water inlet;
18 - output of desalinated water;
19 - brine output.

 Before describing the drawing of figure 3 of the proposed installation, we describe the fundamental, although simple experiment of figure 1 and figure 2.

 Figure 1 shows the horizontal plane raised above the ground on the supports, and the height of the experimental supports R is chosen equal to the radius of the semicylindrical concentrators. The experimental setup was built on a real scale, therefore it consists of two rectangles in contact with the corners, since the course of the expected characteristics was supposedly known. Paper is pinned on the bottom rectangles and every 15 minutes a dot is placed on the paper in the place where the "bunny" of solar reflection, obtained from a small mirror located on the ground, is located. The mirror should always lie horizontally, so it is on a piece of foam floating in a vessel of water.

 Actual values of R are from 125 cm to 200 cm. Based on what they are selected.

 At a distance R from the ground there will be tubular boilers rolling on monorails, which are placed on top of the supports. This entire system must be installed and somehow maintained during operation. R = 200 cm - this is already above average human height, people should work with their hands up or on coasters. At a height of 200 cm, you can still work higher, but the system is no longer worth raising, followed by cost overruns.

 Let us estimate the size of the half-cylinder at R = 200 cm, the so-called “aperture”. Strictly speaking, the aperture is the area of the reflector, but the second component of the area - the length of the half-cylinder - is easily taken into account. In fact, real half-cylinders with an “aperture” of 2R = 400 cm (this is as much as 4 m) should not be used for a number of reasons. Correctly used geometric surfaces are called somehow “tricylinders” or even more difficult with a height not a multiple of the diameter of the cylinder, but the name “half cylinder” has taken root. Let us evaluate the “aperture” of a “half-cylinder” with a height of 30 cm rather than 200 cm, but with a cylinder radius of R = 200 cm. For simple geometric reasons, the width of the “half-cylinder” (aperture) is approximately 210 cm. This is a convincing reflector width, especially so that you can choose a height and a little more than 30 cm. So R = 200 cm is really the maximum size, you can choose it even smaller.

 Why the experiment was carried out with a small horizontal mirror, and not with the "half cylinder" as such. Because this mirror is an element of the ensemble of such mirrors located on the circumference of the "half-cylinder". All the "bunnies" from the entire ensemble will gather on a horizontal plane passing through the center of curvature of the cylinder, where the "bunny" is from the horizontal mirror. There will not be only a concentration coefficient for one element, but it is not required during the experiment.

 The experiment was carried out with the supposedly "tubular boiler" located on the N-S line ("north-south"), which is absolutely not necessary, but convenient. The height of the characteristic H was obtained at a 9-12-hour working day (depending on the month), half the width of L / 2, and the characteristic’s run beyond the west-east line with a long day (around June 21) L / 2 - this is why that the characteristic is symmetrical and there is no need to spend 12 hours on it, 6 is enough from noon to evening.

 It should be noted that since the sun does not appear at its zenith at mid-latitudes, the reflected signal on the horizontal plane is always somewhat shifted north of the reflection point, June 21 is less, September 21 is more. This entails the displacement of the tubular boiler to the north along the axis of the semi-cylindrical concentrator. In this case, the line of energy concentration by the reflector will be located to the maximum extent on the line of the tubular boiler, the minimum will be empty, not illuminated by the energy line sections of the tubular boiler. This refers to the northern hemisphere; in the southern hemisphere, such an offset should be exactly to the south; at the equator, the offset is zero.

Figure 2a shows the curves from two mirrors a and b located on the NS line: 21 — curves obtained in the region of June 21 (strictly on June 21 or another day, the experiment may fail due to cloudy weather): 22 — curves, obtained in the region of September 21, R = 150 cm. Curves 21 are located closer to the reflecting points a and b than curves 22, which is natural due to the higher position of the sun. It can be seen that all lines a and b move parallel to themselves. Curve 22 shows the height H = 140 cm and the width L = 500 cm. Such a value of L indicates that the tubular boiler should move 5 m during the working day, and if it is located on the NS line, the movement should be unidirectional. Curve 21 shows the possible entry of point a to point a ₇ beyond the west-east line in the region of June 21 (0.5 m). Dimensions H and B indicate that the tubular boiler should be longer than the half-cylindrical concentrator from the north end by H, from the south by B. The boiler should be shifted north from the position of the concentrator.

 In FIG. Figure 2b shows the curves drawn by points a and b located on the west-east line, June 21. Analysis of the curves suggests that the movement of the tubular boiler in this case should be bi-directional: from south to north until noon and from north to south in the afternoon. Curves on other days do not add anything new. Unidirectional movement is preferable, no commutation of the motor during working hours. The tubular boiler is returned to its original position before or after work.

 If possible, tubular boilers should be placed along the N-S line. However, this may not work out due to the relief conditions of the working area where the solar installation is located, or because of the configuration of this area. There will be no big trouble, the location of the boilers on the west-east lines or in any intermediate position is permissible. This should only be taken into account in the software device that controls the movement of the boilers. In an intermediate position, the movement should be more complicated, but this will not even affect the amount of memory of the programmer.

 The filling of the storage device is best done experimentally at the location of the installation, since the curves of figa and 2b were taken. Then there will be no doubt about the truth of the result. However, this involves daily characterization during the season, which is rather laborious.

 The characteristics taken in neighboring days are approximately 2-3 cm apart from one another, which is commensurate with the width of the tubular boiler. To control the movement of tubular boilers, information is needed for a given day of the month. Although it is possible to some extent, the adjustment of the characteristics using a computer during the transition to the characteristics of the next day. This relates to the issue of improving the management program of a solar power plant.

 A purely analytical calculation of the characteristics on the computer and filling in the storage device from the computer is also possible, while the geographical latitude of the site and also longitude should be taken into account, because noon, for example, occurs at different longitudes at different times.

 Figure 2c shows the curves drawn by three parallel lines AB, CD, EF, located on the lines N-S. An interesting result was obtained, which is not always immediately clear when speculating the process: the reflection lines are at the same distance from each other at noon, morning and evening. This makes it possible to control the movement of all tubular boilers from a single engine, as well as the ability to rigidly link them together and move the entire boiler system as a whole. Behind this is cost savings.

 The proposed solar power installation (figure 3) is as follows.

 Semicylindrical solar energy concentrators 1 are located on a horizontal surface. The number of them in one block is chosen arbitrarily, in the future this number will be specified in accordance with practical circumstances. The hubs with their axes are located in figure 3 along the line N-S ("north-south"), but another direction is possible.

 The width of one hub is in the range of 200-250 cm and will also be specified. Concentrators are cut from cylinders with a radius of 150-200 cm, the height of the concentrators is 30-40 cm.

 The length of the concentrators ranges from 10 to 30 m and is determined mainly by tubular boilers. If concentrators and boilers of even greater length (50 m, 100 m) can be used, this will be beneficial.

 Hubs can be deepened into the ground or not deepened at all, can be located on supports and have some possibility of rotation for adjustment. All options are selected based on practical amenities.

 If the solar power plant is located on a large area, for example 1 hectare, it is difficult to imagine that this area can be leveled and made perfectly horizontal. Yes, and it is expensive, and most importantly, this is not particularly necessary. Half cylinders fit part with a recess, another part without a recess, the third part on supports. The half-cylinder field is located horizontally as a result.

 In figure 3, the hubs are combined in pairs and paths 8 for service personnel are left between the pairs.

 At the edges of even concentrators in FIG. 3, supports 6 are installed. In fact, the number of supports will also be selected based on practical considerations, the fewer the supports, the lower the cost.

 Monorails 7 are located on supports above the west-east line. The ends of the monorails are bent up. The length of the monorails is equal to the total width of the concentrator block plus several meters (2.5-3.0 m), on which the monorails extend beyond the width of the concentrator block, i.e. the total length of the monorail of Fig. 3 is 20-25 m. The monorails are thermally insulated from below, since they are in contact with the energy line.

 Tubular boilers 2 mounted on rolling devices, which are not visible in FIG. 3, move along the monorails from above. The length of the tubular boilers is equal to the length of the concentrators plus the size H from the north end (about 1.5 m) and the size B from the south end (0.5 m), shown in figa. Tubular boilers pass over the axes of the concentrators at noon, are in the west at a distance of L / 2 from the corresponding axis in the morning and at the same distance in the east in the evening (in Fig. 2a this is 2.5 m). The distances between the tubular boilers are the same and equal to the distances between the axes of the concentrators. The ends of the tubular boilers are rigidly combined on the north side using a cold water pipe 3, on the south side using a hot water pipe 4. There will be no mistake if these pipes are interchanged. Both pipes consist of separate sections, which are connected to the tubular boilers using adjusting nuts 5. For each tubular boiler there are 4 adjusting nuts, 2 from each end. The simultaneous rotation of four adjusting nuts (2 people) moves the boiler parallel to the axis of the concentrator, changing its distance to neighboring boilers, the slow rotation of two nuts somewhat regulates the direction along the N-S axis. In this way, the position of the boilers with respect to the axes of the concentrators is adjusted in order to combine the boiler line with the concentrated radiation line. The total height by which the tubular boilers are raised (the height of the supports plus the height of the monorails plus the height of the rolling devices) is equal to the radius of the half cylinders R of the concentrators 1. The plane in which the tubular boilers move is horizontal and passes through the centers of curvature of all half cylinders 1.

 The hubs 1 are made of plastic and assembled from separate segments, between which there are gaps for the rainwater drain. Aluminum foil is glued on top of the plastic.

 It is important to note once again that bulky hubs, after placement and adjustment, are stationary. In this regard, the requirements for their strength and, accordingly, the consumption of plastic are minimal. Plastic or any other material is the main expense in the construction of solar power plants.

Tubular boilers 2 are pipes with a diameter of 2-3 cm, top and sides covered by a casing, externally coated with an insulating layer. The receipt of thermal energy in them is carried out from below at noon and at an angle of about 45-50 ^o in the morning and evening. Thermal insulation from above and partially from the sides prevents heat dissipation.

Tubular boilers are shifted north with respect to the concentrators. In principle, this shift can be regulated from time to time, on June 21 it is minimal, in the autumn maximum. To do this, tubular boilers are mounted on rolling devices not by welding, but with the help of detachable joints and from time to time manually move along the NS line. However, such a movement during the season can be no more than the distance from point a ₂ to point a _{5 of} FIG. 2a (1.5 m). If the length of the boiler is 30 m, and even more so 50 m, 100 m, it can be neglected. The idle part of the boiler that is not illuminated by the energy line in this case does not significantly affect anything. Boilers should simply be 1.5 m longer.

 Pipes of cold 3 and hot 4 water are completely insulated, only the possibility of access to the adjusting nuts 5 is left.

 The selection of thermal energy from the solar installation is carried out from the outlet of the hot water pipe 4. Due to the fact that this pipe moves together with a system of tubular boilers, its connection with a stationary heat consumer 10 is carried out in FIG. 3 using a flexible pipe 9. Other options are possible. communication.

 It should be noted that the waste water that has been cooled and cooled at the consumer is pumped again through the pump to the inlet of the cold pipe of the installation, and the water does not have to be completely cold, it can maintain a temperature above ambient temperature. It is desirable that the same water circulate in the system and it is desirable that it be distilled.

 Moving the system of tubular boilers 2 and pipes 3 and 4 along the monorails 7 is carried out using a software device 14. At the present level, such a device can have the size and cost of a pocket receiver or player. An executive motor 13 is operated from a software device.

 Due to the fact that the speed of movement of tubular boilers is very small (5 m in 8 hours), a gearbox 12 is provided that winds and coils the beginning and end of the cable 1la and 11b. The cable moves the boiler system in the forward and reverse directions.

 In FIG. Figure 3 shows the fastening of only the cable 11a and is shown conditionally, with the help of a ring for the end pipe. The design of the mount may be different, it is not fundamental. The cables have threaded length adjusters for adjusting the system.

 The proposed solar power plant operates as follows.

 The operator sets the true time on the program device 14, and the program drive moves the rigid system of tubular boilers 2 and pipes 3 and 4 to the desired point corresponding to this time, within 5 m. The operator must make sure that all lines of concentrated solar energy are supplied to the inputs of the corresponding tubular boilers, after which he presses the "Start" button. The clock went from west to east, so the reflected signal moves, tubular boilers began to move, work began.

 Figure 3 presents a picture in which tubular boilers are almost in the extreme position in the east, i.e. at the end of a long working day in the area of June 21.

 If the weather at this moment is cloudy, the Start button is still pressed. The coincidence of the lines of energy and the axes of the boilers in this case is clarified when the sun appears.

 In case of line mismatch, the necessary adjustment of the positions of the respective tubular boilers or concentrators is carried out.

 The operator’s task is also the need to coordinate the amount of water circulating in the system with the amount of energy supplied to the boiler inlets, focusing on the water temperature at the outlet of the pipe 4. This task can be taken up by the automation, in figure 3 this is not displayed.

 As an example of a specific design of a solar power plant, we can consider the hectare of area occupied by such a plant in Russia (Moscow Region) from an economic point of view.

 For such an installation requires: plastic for hubs (10 tons) - $ 5000, aluminum foil (1 t) - $ 1500, supports (100 pcs.) - $ 1000, monorails (2 tons) - $ 1000, pipes (5 km) - $ 3000, steel for the casing of heat insulators (2 tons) - $ 1000, a heat insulator - $ 1000, rolling devices - $ 500, software, executive motors, gearboxes, cable - $ 3000, pump - $ 1000.

 Only $ 18,000.

 We assume that unaccounted expenses (installation, operation, etc.) are also $ 18,000. Total $ 36,000.

 According to some estimates, a hectare of the Moscow Region is capable of producing heat at $ 30,000 a year.

Cheap installation of figure 3 and in cold Russia (110 W / m ² ) will pay off very quickly.

In a hot climate between 35 ^{o C.} w. and 35 ^{o s} . n. when 600 W / m ^{2 of} thermal power reaches the earth's surface, the installation can even be an effective means of attacking deserts during desalination.

 A particularly promising installation when working with desalination plant 10 of FIG. 3 to supply water to large cities. It is advisable that these cities are located near the sea and desert. Examples include Los Angeles, Long Beach, San Diego et al., USA: Tel Aviv, Israel: Perth, Australia. And even the oil producers of Kuwait, Kuwait, Dammam and others, Saudi Arabia, etc. There live solvent consumers of scarce fresh water, and hence the thermal energy of the proposed installation.

Claims (1)

 A solar power plant containing semi-cylindrical concentrators of solar radiation, tubular boilers, supports, monorails insulated from above and from the sides, a program drive, characterized in that the concentrators and monorails are located in mutually perpendicular directions, mainly in the north-south direction - concentrators, " west-east "- monorails, monorails are installed on the top of the supports, the height of the supports is chosen approximately equal to the radius of the half-cylinders, tubular boilers with rolling devices are placed on rkhu of monorails, made with a length slightly exceeding the length of the concentrators on the sides of both ends, shifted towards the north in the northern hemisphere, south in the southern hemisphere, are located at a distance equal to the width of the concentrators, combined by pipes of hot and cold water, and the whole the rigid system of tubular boilers and connecting pipes is connected to the program drive by means of forward and reverse motion cables.

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