Heater This invention relates to a heater as defined in the preamble of claim 1, comprising a closed vessel which contains alternately an evaporating medium and a condensing medium, and which acts cyclically as an evaporator and a condenser.

Prior art heaters provide heat as long as they are supplie with energy or as long as there still remains energy stored in them and/or in the medium. The conventional heat pumps are not cost efficient.

The heating of a fluid is a heat-absorbing, i. e. endothermic rection. At the same time, the pressure increases. The vapour condensates as it touches a wall having a temperature lower than the saturation temperature of vapour, and condensates on the surface, forming a liquid, i. e. a condensate. As the vapour condensates, the heat energy absorbe in the vapour is released, even if it were supplie with additional heat energy. The rection is exothermic. This is a convection process, i. e. transfer of heat along with a circulating fluid.

In a closed system, energy alone can be exchanged with the environment. By contrast, an open system tends to resume its thermodynamic equilibrium, the heat being transferred from a higher energy state to a lower, i. e. from hot to cool. In a closed system, a change in heat energy under constant pressure equals a change in the enthalpy, i. e. the heat content.

These rections comply with the basic rules of thermodynamics.

The purpose of the invention is to stop supplying the fluid with heat energy at the stage when it releases the heat energy it has acquired, which it does in any case as it condensates when heated to the saturation point.

This purpose can be achieved as follows: depending on the enthalpy properties of each fluid, it is heated only when heating can be performed with a minimum of energy bound by evaporation compare to the energy released by condensation.

The heater in accordance with the invention is characterized by the features defined in the characterizing clause of claim 1.

The heater has been tested for instance by heating the fluid in a tank circulating water, and by determining the temperature and the4 eat releases efficiencies as usually, as illustrated in figure 1. Heat release efficiency as a function of the temperature of the surfaces. Determined by circulating water. Mass flow/h x t = kcal/h. Ambient temperature constant + 20 °C.

Curve 1 shows that, the temperature of the heat surface of the fluid being 57°C, the heater releases 300 W.

After this, the heater fluid was heated with a 300 W electric resistance, the temperature of the heat release surface being 75°C and the heat release efficiency nearly 500 W. This is illustrated by curve 2.

When the temperature of a fluid is raised from e. g. 60 °C to 80 °C, approx. 3 kJ energy is required as the pressure rises from 17 kg to 26 kg. When the energy supply stops, the fluid releases approx. 35 kJ of energy as it is cooled from 80°C to 60 °C, i. e. approximately ten times more. However, in practice, this theoretical result is not achieved, the reason for this being that walls of a closed vessel conduct heat to the environment and that the amount of energy absorbe by evaporation is about six times more compare to condensation.

The electrical power supply to the electric resistance of the same heater is regularly cycled so that it is switched off at a temperature of 75°C and switched on when the temperature has dropped to 65°C. Consequently, the average temperature is 70 °C. Figure 2 has been drawn to illustrate the temperatures.

Figure 2. Cyclic energy supply. Surface temperature 70 °C. Environment +20°C. Input 28 min. per hour 300 W = 140 Wh. Average temperature 70°C = 450 W heat release per hour. Ratio 450/140=3.2.

In the course of one hour, heat has been transferred with a 300 W resistance to fluid 28 seconds for one minute, i. e. 140 Wh has been transferred during one hour. Figure 1 shows that the heat release per hour is 450 W, the ratio 450 (released energy) to 140 (absorbe energy) being 3.2.

The temperatures indicated here are those of the heat release surtace, the temperature ot the environment being kept constant. By means of this invention, it is easy to achieve the ratio of 3/5 used in heat pumping techniques.

Figure 3. Summary of test results. MG 211 is 1100 mm, MG 209 is 900 mm, MG 207 is 700 mm and MG 205 is 500 mm long convector.

This invention is also characterized by the fact that heating can be done with a direct electric resistance and/or a hot fluid, which may be heated by means of any form of energy. Besides the great benefits described, this invention provides appreciable savings,-the power requirement dropping to about one fourth-production costs not notably higher than those of conventional radiators, and small space requirement, with as simple installation as possible. It can be installe in a central/district system without cutting the pipe, and even without tools.

Figure 4. A study of the enthalpy curves of substances provides concrete data.

Figure 5. Function of an absorption heat pump according to the Canot circle.

The enclose graphs illustrate the enthalpy curve of a refrigerant, showing also the result confirme by tests, in which, when the fluid was heated with 400 W, the temperature rise from 65 °C to 75 °C took two minutes, and the heat release from 75 °C to 65 °C took four minutes.

The mathematic argument of the heater is as follows: THE FIRST LAW OF THERMODYNAMICS Energy does not disappear. The output can not be more than input. Energy transforms to lower level as follows: Electricity Pressure _ High temperature s t Low temperature Calculatory this can be shown as follows: -electricity resistance of 300 W, iron, volume 47 cm3, temperature 370°C -300 W = heat 430 m3 air 2°C (20-22)

-300 W = heat 129 liter water 2°C This means that opposed direction is against nature. Heat transforms always from warm side to cool side. Cooling needs further energy.

When natural transform happens, the amount of energy (Q) is always same.

THE SECOND LAW OF THERMODYNAMICS The output is same or less than input because of loses, entropy. This law is related to the heat transform according to Canot.. It isA Q= T I-T2/T I xT2. Q is amount of energy, T I = starting temperature and Tel-= final temperature The outcomes of this are (using Kelvin 1 K is energy).

1) Theoretically it is possible to reach heat factor 10. <BR> <BR> <BR> <P>2) The smaller is difference between TI and T2 the bigger is heat factor. t Q is a relative notion, not absolut amount of energy.

3) Q has nothing to do with the balance-sheet of energy.

4) According to Canot the ideal motor or heat pump can reach the heat factor 10. The reason why this is not in practice possible is entropy. The loses cause of frictions, outside (mechanical) and inside (liquid). The conventional heat pump creates the pressure by compressor and can reach maximum heat factor 3.

The amount of energy and the balance-sheet of energy can not be determined without the enthalpy of substance. Every substance has own enthalpy shown often by a curve. The variables of these curves are energy (Joule, J), temperature and pressure (Bar).

The definitions are: 1 kJ = 240 kcal = 0,26 kWh, energy is combine to mass (g) or volume (1) or time (h). Energy is always connecte to the time, so we use Wh or kWh, not W or kW.

To heat 1 liter water 1 °C = 1 kcal To make pressure 1 Bar of 1 dm3 air requires 100 J latent energy The example: We use the refrigerant R134a and it s enthalpy curve.

In several test is used 900 mm long convector, the volume of R134a is 0,43 dm'. The weight of saturated vapor is 142 g/dm3. We need 0,43 x 142 = 61 g vapor.

I Heating from °C to 30 °C: Input energy according to the specific gravity 16 J/g = 16 x 61= 976 J The boom of pressure according to enthalpy 4,6 Bar = 4,6 x 43 J= 198 J INPUT ENERGY + LATENT ENERGY= 1.174 J OUTPUT IS ALSO 1.174 J, BUT COMPARE TO THE INPUT 1175/976 THE BEAT FACTOR IS 1,2.

2 Heating from 50 °C to 80°C : Input energy according to the specific gravity 4 J/g 4 x 61= 244 J The boom of pressure according to enthalpy 13 Bar = 13 x 43 J= 198 J INPUT ENERGY + LATENT ENERGY= 803 J OUTPUT IS ALSO 803 J, BUT COMPARE TO THE INPUT 803/244 THE HEAT FACTOR IS 3,29.

3 Heating from 80°C:to Input energy according to the specific gravity 1 J/g = 1 x 61= 61 J The boom of pressure according to enthalpy 5 Bar 5 x 43 J= 215 J INPUT ENERGY + LATENT ENERGY= 276 J OUTPUT IS ALSO 276 J, BUT COMPARE TO THE INPUT 276/61 THE HEAT FACTOR IS 4,52.

It is possible to make several conclusions. According to the second law of thermodynamics the entropy is smaller when difference of temperatures is as minimum as possible and the temperatures are higher than of a conventional heat pump.

Those skilled in the art know that a timer or a thermostat can control cyclic heat energy supply.

Theoretically this kind of an absorption heat pump also is known in the literature, for example Nationalencyklopedin, 1996 Bokförlaget Bra Bocker AB, Höganäs, page 132.