WO1991016588A1

WO1991016588A1 - Heat/cooler transfer device

Info

Publication number: WO1991016588A1
Application number: PCT/EP1990/000620
Authority: WO
Inventors: Jan Borg
Original assignee: Jan Borg
Priority date: 1990-04-17
Filing date: 1990-04-17
Publication date: 1991-10-31

Abstract

A procedure for improving the efficiency of a heating system, the heating system comprising one or several heater elements (7) inside which, in an enclosed space (2, 5, 6), is circulated a heat transfer fluid of which the pressure increases exponentially with increasing temperature. The object of the invention is to improve the efficiency of the heating system. This is carried out in the invention in that the temperature and pressure of the heat transfer fluid contained in the heater element (7) are varied by switching the heating of the heat transfer fluid alternatingly on and off.

Description

HEAT/COOLER TRANSFER DEVICE

Th e present invention relates to a method and an apparatus tor imoroying the etficiency of a heating system which may comprise one or several heater apparatuses i ns i de which iscirculated a heat transfer fluid.

The prior art comprises radiators inside which iscirculated for instance water or vapor, in order to transfer heat to the radiator and further to the ambient air. whereby the water or vapor is circulated through some kind of heater in order to be heated after having given off heat to the radiator or several radiators. Thus, the water or vapor acts to transport the heat between the heater and one or several radiators, and the heat given off by the water or vapor corresponds to the heat supplied by the heater.

The object of the present invention is to achieve a method and an apparatus which make it possible to improve the efficiency, in that the energy consumption is less than the heat given off by the apparatus.

The present invention makes use of a fluid which condenses and

evaporates in a closed circuit inside a heater apparatus, the evaporation being caused by supply of heat.

An advantageous embodiment ot the method comprises that the heat is supplied by means of a fluid which itself is heated about 10 % of the time which the apparatus is used.

The apparatus may for instance be a radiator containing a closed circuit for circulation of a fluid, for instance Arcton 22. being at a pressure of for instance 50 to 60 N/cm2. The circuit may comprise one or several loops which are surrounded by ribs or baffles in order to increase the heat transfer area. The loops are coupled to an internal heat exchanger, in which heat is supplied to the fluid. The internal heat exchanger may for instance be a horisontal tube which isclosed at both ends and contains a conduit extending longitudinally through the tube. A heating fluid, for instance water having a temperature slightly above the evaporation temperature of Arcton 22 at the existing pressure, for instance 95 oC. flows through the conduit, and heat is transferred to the Arcton. The loop or loops of the closed c i rcu i t is/are coupled to each and of the horizontal tube, at different heigths. and evaporated Arcton will enter the hiohest end of the loop or loops and rise inside the closed circuit. The vapor will give off heat and at least partly condense, and the liquid will flow down to the horisontal tube. This process will continue as long as a certain amount of the heat is transferred from the conduit. The heat given off by the vapor is transferred through the walls of the tube constituting the closed circuit, and the heat may for instance be transferred to the ambient air by convection.

The fluid, for instance Arcton 22, inside the closed circuit circulates without the use of pump.

Alternatively to the use of a conduit through the horisontal pipe for supply of heat by means of a flowing fluid can be used another kind of heating means, for instance an electric heater.

In order to increase the heat transfer area in contact with the ambient air the tube of the closed circuit may, in a perse know manner, be equipped with ribs or baffles externally.

The apparatus according to the invention can be utilized in a system for instance for house heating, in which several apparatuses may be coupled in series, whereby the conduit for the flow of of the heat supply fluid runs through all the apparatuses. and means such as a valve may be provided for switching the circulation on and off. Means may also be provided for varyino the temperature and pressure of the heat supply fluid. The efficiency of a heating system provided with the characteristic features presented in the foregoing has been found to be considerably superior to that before.

In the following, the invention is described more in detail with the aid of an example. referring to the drawing.

Fig, 1 presents the vertical section of a radiator appropriate for use in the present invention.

Fig.2 presents schematically a house heating system in which the procedure of the invention is applied.

Thus, in Fig. 1 is presented the radiator or heater element in which the method of the present invention can be applied. The radiator comprises a hori zontal heat exchanger in consisting of a tubular container 2 containing a fluid, such as Arcton or equivalent, both in gaseous and liquid form, which evaporates with the aid of a heating conduit 3 passing through the heat exchanger. To the container 2 is connected a heat exchanger element 4, in which the fluid in gaseous form gives off heat to the ambient air and condenses at the same time. The element 4 is composed of a plurality of vertical pipes 5 connected on the top margin of the container 2.

In Fig.1, the pipes 5 have been connected. to the bottom pipes.

Ir, Fig.2, the heater elements of the kind described above are indicated by reference numeral 7. The house heating system depicted in Fig.2 comprises additionally a heating boiler 8, a water pipeline 9 and a shut-off valve 10.

The normal situation was previously that the water circulates in the system all the time, whereby the surface temperature of the heater elements 7 has settled on a certain level. In the method of the present invetion. the water circulation is automatically interrupted with the shut-off valve for a certain period, ofinstance for a few minutes, whereby the water momentarily heated to a temperature consi derabl y higher than that which itwould have if itwere circulating all the time. When the water has reached an appropriate temperature. the valve 10 opens and the water is again allowed to circulate in the heater elements 7. The hot water causes the Arcton in the heater element to be heated and to evaporate instant aneously, Hereby the surface temperature of the element rises rapid'y above the temperature which would have been achieved with continous water circulation, and it goes down very slowly back to this said

temperature. The advantage is gained owing to the pressure of Arcton increasing exponentially in relation to the temperature. In precise measurements which have been carried out, the improvement of efficiency has been indisputable. In one experiment, the surface temperature of the radiator had stabilized at 54 in continuous operation. The radiator was then tipped over on its side, whereby the gaseous arcton could not ascend in the pipe 5 and remained instead in the heat exchanger 1 to be heated further. The radiator was kept lying on its side for three minutes, during which time the surface temperature of the radiator at a given point decreased to 48 ,whereafter the radiator was pieced upright once more and the arcton could ascend. The sureface temperature of the radiator rose to 60 in one minute and begin thereafter to go down very slowly, reaching the limit of 54 only after half an hour. In this way, the surface temperature of the radiator could be held most of the time over 54 which ismean temperature in a continuously operating radiator.

Naturally, tipping radiators cannot be considered in actual practice, but it was easy to demonstrate by this experiment that a remarkable

improvement in efficiency is achieved with the aid of the invention, seeing that the fundamental principle of the procedure of the invention is the same as in the experiment. The invention is based on increasing the temperature of the arcton momentarily considerable above the average temperature.

Measurements have been carried out during use of radiator in accordance with the invention. Heat was supplied in an amount of 0,5 kW. Based on measurement; of the velocity of the ambient air upwardly through the radiator, the cross sectional area of the radiator through which the air flowed, and the temperature of the ambient air when coming up above the radiator the output was calculated to 1,17 kW.

Claims

Cl aims

1. A method for improving the efficiency of a heating system, which may comrises comprising one or several heating apparatuses inside which is circulated a heat transfer fluid, the or each apparatus being a heat exchanger for transferring of heat from the heat transfer fluid to a surrounding medium, characterized in that the heat transfer fluid is kept at a temperaure approximately corresponding ti itsevapotaion temeraure, by supplying heat to the apparatus, in order to cause that the heat transfer fluid evaporates and condenses when flowing in a closed circuit.

2. A method as claimed in claim 1, characterized in that Arcton, ammonia or another medium is used the heat transfer fluid.

3. A method as claimed in claims 1 or 2, characterized in that the fluid is Freon 12. which has a pressure of 50 to 60 N/cm2 and is kept at a temperature of 90 to 150 oC while circulating in the circuit.

4. A method as claimed in claim 1, 2 or 3, characterized in that heat is supplied by means of a primary fluid supplied to a lower region of circuit.

5. An apparatus for performing the method of one or more of the claims 1 to 4, characterized in that it comprises a closed circuit for circulation of a heat transfer fluid, the apparatus being a heat exchanger for transferring of heat from the transfer fluid to a surrounding medium, said apparatus comprising means for supply of heat to the apparatus in order to keep the heat transfer fluid approximately at its evaporation temperature.

6. An apparatus as claimed in claim 5. characterized in that the means for supply of heat is situated at the lower region of the closed circuit, whereby evaporated heat transfer fluid can rise in a first portion of the circuit and condence in a second portion of the circuit.

7. An apparatus as claimed in claim 6, characterized in that the closed circuit comprises a lower heat exchanger for evaporation of the heat transfer fluid, the remainder of the circuit being one or several tubes, each of which being connected to the heat exchanger.

8. An apparatus as claimed in claim 7, characterized in that the lower heat exchanger comprises a jacket which surrounds or contains a heater element, wherein the space between the jacket and the heater element is a part of the closed circuit.

9. A heat system, characterized in that it comprises several apparatuses as claimed in one of the laims 5 to 8, coupled together by means of a conduit for supply of a primary heating fluid to all the apparatuses.