JPS6078250A - Boiler utilizing solar heat - Google Patents

Abstract

PURPOSE:To contrive to improve the operation starting efficiency by a method wherein lines to supply steam from outside to down comers are provided in order to forcibly produce circulating water flows while warming up boiler water by supplying the steam at the initial raising of boiler water temperature. CONSTITUTION:When the raising of boiler water temperature is intended, the heat stored in an accumulator 10 in the form of compressed water due to the operation on the previous day is taken out by flashing operation in the form of steam (d) and led to a pipe line 9. At the same time, the solar rays are irradiated over boiler parts 4 by putting the facilities of solar concentrating system into work. The steams (d) pass a down comer header 3 and ascend the boiler parts 4 so as to heat boiler water by the latent heat of condensation while condensing at the boiler parts 4 during ascending. At the same time, because strong circulating water flow is developed by the buoyancy of steam bubbles and consequently the uniform rising of boiler water temperature is resulted, the occurrence of water hammering and generation of hot spots at the initial raising of boiler water temperature can be dodged. The full utilization of the facilities of the solar concentrating system can be possible without increasing the power consumed in a plant. At the same time, the time for raising boiler water temperature can be shortened.

Description

[Detailed description of the invention] The present invention relates to a solar heat boiler such as a tower concentrator type.

In conventional solar boilers of this kind.

As shown in the system diagram in Figure 1, when the boiler section 4 is heated by sunlight a, circulating water flows due to the temperature difference between each can of water, and the temperature of the entire can of water gradually rises. When the pressure in the water drum 1 reaches a set value, the valve 7 opens and steam C is removed.

Here, 2 is the downcomer pipe and 3 is the downcomer header.

5 is a boiler header for a riser pipe, 6 is a riser pipe, and 7 is a drum pressure control and steam extraction valve. Note that the downcomer pipe 2 refers to the pipe from the air/water drum 1 to the downcomer header 3.

However, in such a solar heat boiler, the sunlight a is partially too strong p.

Or, if the light-receiving surface of the boiler section 4 has an inclination with respect to the direction of gravity, water circulation is inhibited.

Since water hammer and heat spots may occur, the current practice is to set a certain limit on the temperature increase speed at the time of start-up, that is, when the equipment starts operating, and to reduce the amount of light collected to match the limit. Therefore, the light collection system equipment cannot be fully utilized, and the light collection efficiency decreases.

What is generally considered to be a countermeasure against this problem is
As shown in FIG. 2, this is a method of forcing water circulation by providing a forced circulation bonder 81 in the downcomer pipe 2. However, with this method, the pump driving power (
(electricity), which is profitable for solar thermal equipment.

This is extremely disadvantageous.

The present invention has been proposed in view of the above circumstances, and aims to provide a highly efficient solar boiler that includes a steam drum, a downcomer pipe, and a boiler section. By installing a line to supply steam from the outside, steam can be supplied at the initial start-up.

The system is characterized by making the start-up process more efficient by forcibly creating a circulating water flow while warming the canned water.

An embodiment of the present invention will be described below with reference to FIG.

In Figure 3, the same symbols as in Figure 1 indicate the same members and equipment, 9 is a piping line that supplies steam to the downpipe, and 1o is a pipe line that supplies steam C taken out from the boiler to pressure water. It is an accumulator that stores heat in the form of .

When starting up such a device, first of all.

The heat stored in the form of pressurized water in the accumulator lO due to the previous day's operation is taken out as steam d by a decompression operation and guided to the piping line 9. Alternatively, steam may be separately prepared and guided. At the same time, the condensing system equipment is operated to irradiate the boiler section 4 with sunlight. The steam d led to the piping line 9 passes through the downcomer header 3 and rises in the boiler section 4, where it condenses and warms the canned water with its latent heat, while at the same time generating a strong circulating water flow due to the buoyancy of the steam bubbles. Since the water temperature can be raised almost uniformly, it is possible to avoid water hammer and hot spots during initial startup. As described above in the above embodiments, according to the present invention, it is possible to fully utilize the light condensing system equipment without increasing the internal power of the plant, and at the same time shorten the start-up time due to the canned water preheating effect. becomes possible.

[Brief explanation of drawings]

1 and 2 are system diagrams showing a conventional solar boiler, and FIG. 3 is a system diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Air/water drum, 2...Down pipe, 3...Boiler header for down pipe, 4...Boiler section, 5...Boiler header for riser pipe, 6...Rising pipe, 7...・Drum pressure control and steam extraction valve, 8... Forced circulation pump, 9...
・Steam supply piping line, 10... Pressure watercolor heat storage (accumulator), a... Sunlight, b... Circulating water flow,
C... Boiler generated steam, d... Boiler supplied steam. Fth Senman 2nd Kingdom

Claims (1)

[Claims] In a solar boiler equipped with an air/water drum, a downcomer pipe, and a boiler section, by installing a line that supplies steam from the outside to the downcomer pipe, steam is supplied at the time of initial start-up to heat a can of water while circulating water flow. A solar heat boiler characterized by forcibly producing.