BACKGROUND OF THIS INVENTION

Until now, how to incorporate a heat accumulator effectively and permanently, in the existing heat exchange systems or in heating boiler construction.

Besides, as the cost of energy has increased, energy saving attempts were made to turn cheap night electric energy for daytime use in practical application. A method to transform cheap night electric energy into heat and store it for daytime use was disclosed as PCT patent No. 0183327 to present a contact heat accumulator arrangement and another PCT patent No. 0183328 also discloses a heat accumulator arranged in heat exchange relation with a cooling/heating machine.

An EPO patent application No. 83903597.9 discloses a more effective heat accumulator in combination with a heat exchanger. Such a known method employs for instance a water tank as storage vessel, which requires a bulky space and cost demanding constructions to provide an energy storage capacity at a reasonable level. Other known constructions also demand some complex and expensive arrangements which offset the advantage of using cheap night energy. In the prior art the heat accumulator is connected in series to a heating system, and large volume heat transfer pipes of chamber type are arranged in a heat accumulator block of high capacity.

The pipes are so dimensioned that vapour is formed in the chamber, when

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there is no heat transfer from the block. On restarting the heat transfer the vapour is continuously let out from each chamber. Such operation involves control problems.

SUMMARY OF THIS INVENTION

In order to reduce the danger of uncontrolled vapour distribution there is suggested a condensor for each outlet the vapour released from individual chambers on the outlet of the accumulator. Another system employs an auxiliary heat accumulator including an expansion vessel, a pump and a pump control means sensing the temperature in the system heated by the heat accumulator.

This invention relates to the pipes for letting out water, as a heat transfer marterial, in vaporized state in the heat accumulator.

This invention provides a steam condensing method and its apparatus to rapidly condense steam a heat transfer material, into hot water in such the heat control apparatus. Other materials besides water may be used as heat transfer material. For the convenience of explanation of this invention, water is used as a heat transfer material in the following. The heat accumulator includes a body of such a material as cast iron, or ceramics having a high heat capavcity and a high melting point, and the body is arranged to be heated by electric energy to a teverature considerably higher than the maximum temperature of the heat exchanger in the night time from 10 p.m. to 6 a.m. The heat accumulator body heated by electric energy is covered with insulator to keepheat in it. In the daytime from 9 a.m. to 6 p.m., when electric energy is

generally used for factories and businesses, the heat stored in the heat accumulator is drawn out to make hot water for home use. The heat accumulator may be heated by the same cheap electric energy as that of night during lunch break from 12 a.m. to 1 p.m.

A piping for transporting water of a relatively low boiling point, is arranged as a heat transferring passage for the heat exchanger and the heat accumulator body.

A circulation pump is arranged in the piping for water transport between the accumulator body and the heat exchanger and on its suction side has a piping in communication with an expansion vessel so as to stand the maximum pressure, and a temperature sensing means is so arranged that the pump stops when the heat exchanger reaches a predetermined temperature, thereby keeping in the piping in the accumulator body dry vapour in a state of moderate pressure generated in the expansion vessel.

Consequently, when the pump receives a start signal from said temperature sensing means for renewed heat transfer between the heat accumulator body and the heat exchanger, vapour is instantly let out to fill the piping.

To prevent unnesessary heat loss, the vapour must be transformed, instantly into hot water of predetermined temperature. The heat exchanger may have an expansion vessel of either open type or closed loop type to stand the expansion pressure. The control device of the pump preferably employs a thermostat or a thyristor device for sensing the temperature of the water in the heat exchanger system or at the inlet or outlet from the heat exchanger. The heat accumulator body is for instance manufactured from a ceramics

material having approximately the following composition, comprising by weight90X HgO, 4X Si02, 4% CaO and 2% different kinds of oxides.

The heat accumulator consists of ceramics material, and heating wires are placed in holes in the ceramics material and connected in series to an electric supply source. The heat pipes are arrnged in the heat accumulator body is covered with thick insulator and can be coated with heat reflective layor or reflector film for better heat consevation.

Pipe are inserted into the heat accumulator to pass water therein and exchange heat between the heat accumulator body and pipe system. The circulation speed of circulation pumps can be controlled by thermostat or thyristor in the system in association with the temperature of inlet pipe or the temperature difference between input and output.

This invention relates to the method and its apparatus to rapidly make hot water of low temperature and from vapour of high temperature and in the course of passing vapour, in the pipes of heat accumulator in the heat accumulating system consisting of a heat accumulator and a heat exchange system, to an exchanger for a floor heating system. This invention is not limited only the heat accumulator, but also relates to the method or apparatus for making hot water condensed from steam of high temperature in all kinds of heat transfer system. The steam condensing method and its apparatus only is explained hereinafter.

This invention relates to a method for rapidly obtaining hot water by spraying cold water into the heated steam in closed room in heat exchange system. In the prior art, several methods were used to make hot water from

vapour, but it took long time.

BRIEF DESCRIPTION OF THE DRAWING

This invention will become more fully understood from the detailed discription given hereinbelow and the accompanying drawings which are given by way of illustration only, and wherein;

Fig. 1 is a block diagram of a heat accumulator according to this invention

Fig. 2 (A) (B) are schematic diagrams of a steam condensing apparatus in accordance with this invention.

Fig. 3 & Fig. 4 are other embodiments of the heat accumulator according to this invention.

* The numerals in the drawings indicate the following elements

Numeral 1 indicates a heat accumulator, numeral 2 indicates an electric heating wire, numerals 3 and 8 indicate pipes, numeral 4 indicates an adiabatic material, numerals 5 and 6 are circulation pumps, numeral 18 indicates a steam condensing apparatus, numeral 7 represents an assistant heat accumulating tank, numeral 30 represents a hot water tank, numeral 16 represents a radiaator, numerals 20 represents a control unit, numeral 24 represents a thermostat, numeral 14 represents a heat accumulating system, numeral 25 represents an expansion chamber, numeral 17 represents a connector and numeral 19 represents a cold water valve.

DETAILED DESCRIPTION OF THIS INVENTION

Fig. 1 illustrates a schematic block diagram including a heat accumulator and a heat exchanger in accordance with this invention.The heat accumulating material in heat accumulator is heated by electric heating wire (2) connected to the control unit (20) controlling the power supply. The heat accumulator (1) can be heated to 600° C sometimes to 850" C and the heat is stored in a heat accumulating material such as cast iron, or ceramics. For use of the stored heat, the water in pipe (3) in the heat accumulator (1) circulates by the operation of circulation pumps (5) (6) and the heat accumulated in heat accumulator (1) is delivered through steam condensing apparatus (18) to hot water tank (30). Cold water filled in the hot water tank (30) through inlet (34) is heated by the hot water in pipe (3) with the help of fan (9) and supplied from outlet (35) to the kitchen or bathroom and other uses.

The pipe (3) may also be connected to radiator (16) so as to heat a bedroom or livingroom. As explained in the above, expansion chamber (25) may be installed in a closed type in pipe (3) or saperately in an open type on the outside. The circulation pumps (5) (6) supply low-temperatured water to the heat accumulator (1).

The control unit (20) which also controls night electric supply constitutes a heat accumulating system (14) with heat accumulator (1). In case of being heated beyond the capacity of heat accumulator (1) or upward of 600° sometimes upto 850 ^* C, the excess heat is stored in an auxiliary heat accumlating tank (7) which may be provided in plurality to increase the

capacity of heat accumulation. Heat accumulators (1) can be connected serially or para1leily in accordance with the size of house or heating space to control the capacity of heat storing.

Explaining the apparatus according to this invention in detail, the water of high temperature in heat accumulator (1) is let out in vapour state by the opertation of pumps (5)(6), and delivered from heat accumulator to steam condensing apparatus (18), and the steam of high-temperature is sent into steam condensing apparatus (18) to be cooled rapidly. Usually it takes long to cool to result in many problems in heat exchange systems.

So this invention provides a steam condensing apparatus (18) to solve the problems, as illustrated in Fig. 2(A)(B). The steam condensing apparatus (18) is composed of an inlet entering the steam of high-temperature in higher position than the center of steam condensing apparataus (18) connected with the pipe of heat accumulator (1), and an outlet (11) near the ground on the opposite side of the inlet (10), and air exhaust valve (12) to exhaust air during the first operation. The spray pipe (13) with many holes branched from the circulation pump(5) is installed in front of inlet (10), and another spray pipe (13') may be added to the upward part of steam condensing apparatus (18) and sprays the cold water of low-temperature into the inlet (10).

Therefore the steam of high-temperature is mixed with the cold water of low-temperature to rapidly make the hot water of high-temperature. The hot water is delivered into radiator (16) and hot water tank (30) through outlet (30).

The operation of the steam condensing apparatus (18) connected to the

whole system will be explained with Fig. 2 (A) (B) as follows.

In Fig.2(A), when circulation pump (5) supplys the cold water of low-temperature to heat accumulator (1), owing to the inner high-temperature of heat accumulator (1), there is some steam which will be flown out of the pipes (3). The control unit (20) control the circulation pump (5) to open the cold water valve (19) and spray the cold water of low-temperature into the steam condensing apparatus(18).

Consequently, the opening of the cold water valve (19) of circulation pump (5) concurs with the entering of the hot steam of high-temperture into the steam condensing apparatus (18), when the temperature of the supplied water into hot water tank (30) through outlet (11) of steam condensing apparatus (18) becomes over 90° C, thermostat (33) actuates to stop the operation of circulation pump (5) and start the operation of low speed circulation pump (6) in stead of the circulation pump (5). The high speed circulation pump (5) is used only 30 seconds at the first part than the low speed circulation pump (6) operates at normal speed to supply the low-temperatured water. To remove regards caused by the air in the pipe during the operation of circulation just after the installation of heat accumulator (1), the air exhaust valve (12) must be pressed to get rid of air bubbles in the heat accumulator (1). The expansion chamber (25) is installed in a closed type as shown in the figure or in open type at outside to endure the expansion caused by the steam.

In Fig. 2 (B) the combined figure of this invention with Fig. 2(A) and and Fig. (4) is described which operates the same as Fig. 2 (A), so

description is omitted.

In an embodiment according to this invention, the structure of the device to spray low-temperatured cold water is effectively formed to spray cold water directly into the steam coming from the inlet (10) and spray the cold water into the steam held on the upper part of the steam condensing apparatus (18) at the same time. As another embodiment of this invention, the steam condensing apparatus (18) is formed in a rectangle and has many upper cold water spray pipes (13') of steam condensing apparatus (18) with many spray nozzles (23') on the top and many lower cold water spray pipes (13) of steam condensing apparatus (18) with many spray nozzles (23) at the bottom in Fig. 3.

As the other embodiment of this invention, the steam condensing apparatus (18) is formed in a obtongshape and has long cold water spray pipe (13) with many spray nozzles in Fig. 4. As explained in the above, the method and apparatus according to this invention have the advantage of optimizing the effectiveness of heat accumulator (1) to reduce the operation time of the apparatus and increase the efficiency of heat exchange to make the hot water of appropriate temperature rapidly with spraying cold water into the high-temperatured steam in the steam condensing apparatus (18) or spraying cold water returned from heating system for example floor heating system.