WO2006021162A2

WO2006021162A2 - Heating system

Info

Publication number: WO2006021162A2
Application number: PCT/CZ2005/000063
Authority: WO
Inventors: Jirí STREIT
Original assignee: Streit Jiri
Priority date: 2004-08-23
Filing date: 2005-08-17
Publication date: 2006-03-02
Also published as: SK50162007A3; SK287475B6; CZ296026B6; WO2006021162B1; WO2006021162A3; CZ2004899A3

Abstract

A heating system consisting of at least one heating circuit comprising a compressor (1) with its delivery connected to the operating medium line (2) with the internal diameter of the metal tube of 3 to 70 mm; to the operating medium line (2) at least one heating unit (4) is connected and its delivery is connected to the operating medium return line (5). The operating medium return line (5) includes at least one throttle device (6), first cooling coil (7) with identical or smaller internal tube diameter than the operating medium line (2) followed by second cooling coil (8), which is connected to the operating medium pressure equalizer (12) and its delivery is connected to the input (13) of the compressor (1). The operating medium is selected from a group formed by fluorine, helium, ammonia, freon or their mixtures.

Description

Heating system

Field of the invention

The invention deals with a heating system for heating up namely residential areas exploiting a compressor.

Background of the invention

AU existing methods of heat extraction are based on a principle of converting a heating medium into thermal energy by combustion. Combustion is used to extract heat from wood, turf, coal, biomass, fuel oils, oil (diesel) and gas.

Disadvantages include high labour intensity during the resources extraction, transport of large volumes of materials to the heat extraction facilities, high labour intensity during the heating itself, damages to the environment by mining as well as by combustion products and consumption of non-renewable resources.

Other disadvantages further include high and rather varying price, where the price ratio of individual heating media changes very often while the conversion of heating boilers to process different heating fuels is expensive. Heat can be extracted from the ambient environment where the closed system performs gas liquefaction and expansion using a compressor - one side of the system is cooling down and the other is warming up. Such heat pumps' purchase costs are high, their close environment gets cooled, they require terrain adjustments and construction modifications during installation. In most cases they are less efficient during winter period when the needs for heating are the highest and therefore additional heating source is required.

Solar collectors may serve as another heat source — at present, they are used only as a subsidiary source.

Principle of the Invention

Disadvantages described hereinabove are removed by a heating system based on the heat pump principle according to this invention; its substance is that it comprises at least one heating circuit, which consists of a compressor with its delivery connected to the operating medium line with the internal diameter of the metal tube of 3 to 70 mm; to the operating medium line at least one heating unit is connected and its delivery is connected to the operating medium return line; the operating medium return line includes at least one throttle device, first cooling coil with identical or smaller internal tube diameter than the operating medium line followed by second cooling coil, which is connected to the operating medium pressure equalizer and its delivery is connected to the input of the compressor; and the operating medium is a gas selected from a group formed by fluorine, helium, ammonia, freon or their mixtures. The operating medium return line's tube diameter is advantageously identical or smaller than the internal diameter of the operating medium line. The throttle device is formed by a nozzle or a throttle valve.

The operating medium line, the operating medium return line and both the first and second cooling coils are made of copper tubes. The operating medium line may include a circulation pump situated downstream from the compressor.

The heating circuit advantageously includes a gas filter and at least one check valve and a pressure gauge. The heating system may include multiple interconnected heating circuits. The operating medium pressure in the heating circuit varies from 0.5xl0⁵ Pa to 30.4xl0⁵ Pa. When electric power is switched on the compressor puts the operating medium into circulation. In order to accelerate the operating medium circulation, a circulation pump may be advantageously used. The operating medium, and from it subsequently also the compressor, tubing and heating units, warm up to the temperature up to 150 °C. A compressor, which would allow reaching higher temperatures of the operating medium, may be used. For a short time, temperatures as high as 700 °C may be reached. Heating units - radiant heaters - transfer the heat to the ambient environment. A water heat exchanger may also be used as a heating unit where the heat of the operating medium is transferred into the water and distributed to conventional water radiators. As yet, such a heat transmission results in high heat-loss rates. Measured heat pump factor during heat transfer into the water was only 2.6, while the measured heat pump factor using the radiant heaters was 17.78. The operating medium cools down in the heating units and is liquefied at temperature approx. +40 ⁰C and with temperature gradient of 50 to 100 °C. The operating medium travels back to the compressor through the operating medium return line. Before reaching the compressor, the operating medium passes through the throttle device, which has smaller section than is the section of the operating medium return line. As a throttle device may be used a nozzle or a regulation valve, which allows continuous adjustment of the aperture, through which the gas passes, and thus it allows adjusting the ratio of the gas pressure at the compressor input and the gas pressure at the compressor delivery. Temperature and the amount of heat released depend on the ratio of these pressures. The pressure ratio is adjusted depending on the heating system size. The operating medium temperature after it has passed the throttle device may decrease down to -40 °C, normally however it decreases to +20 to 40 ⁰C. Downstream from the throttle device the operating medium passes through the first cooling coil and the second cooling coil, which is wound around the compressor body, which firstly cools the compressor to prevent overheating and, secondly, it serves to pre-heat the gas by the compressor before it is taken to the compressor's input. Before entering the compressor, the gas passes through the pressure equalizer, which has bigger diameter than the return line, here the gas pressure is decreased so that the compressor would be capable of sucking in the gas. A gas filter may be advantageously inserted into the heating circuit to intercept possible impurities in the circuit. The circuit includes also a valve for charging the system with the operating medium and a pressure gauge.

The heat dissipated to the ambient environment by the heating units of this heating system is up to twenty-times higher compared to the amount of supplied electrical power used for driving the compressor. As an advantage, an air-conditioning unit may be connected to the return line.

The main advantage is the cost for heating, which compared to electrical heating saves up to 90% of costs.

The purchase price for the heating system is also favourable.

The heating system according to the invention is very easy to install and to operate. The compressor is small and also the used heating convectors for heat dissipation may be very small in size.

The complete heating system may be minimized by shortening the lines and incorporated into a single compact block thus making the heating system portable. No chimneys to exhaust combustion products are necessary because during the heat transfer no by-products are created.

The system is environmentally friendly by its low power demand factor as well as by the fact that it creates no exhaust products. Using an exchanger, the heating system may be connected to an existing heat distribution system.

Overview of Figures

Figure 1 shows schematic connection of the heating system for heat production. Figure 2 shows temperature measuring points in the heating system.

Examples of the Invention Application

Example 1 Example of the invention application is obvious from fig. 1.

The compressor 1 is equipped with electrical power supply. To the compressor 1 is attached the operating medium line 2, the operating medium is fluorine. The circulation pump 3_. is located between the compressor I and the three heating units 4 to provide faster circulation of the operating medium and subsequently also quicker warming up of the heating units 4, which are formed by radiant heaters. The heating unit 4 may be hinged on a wall, embedded to the floor channel or in-built in the wall. Liquefied operating medium returns from the heating units 4 through the return line 5 via the throttle device 6, the first cooling coil 7 and the second cooling coil 8, via the gas filter 9 for separation of possible impurities, via the check valve .10, the pressure gauge H and the pressure equalizer 12 through the input 13 to the compressor 1.

The system functionality was verified using the compressor 1 with power consumption 2.8 kW. The connection was made using three-phase current 380 V, 50 Hz. Three heating units 4 were installed to dissipate the heat, their total capacity was 30 kW at the temperature gradient 20 ⁰C. Within 23 minutes from starting the operation all convectors reached temperature 94⁰C. During another 3 hours, the electric supply meter indicated the power consumption of 9.9 kWh. Temperature of the heating units during the period of 3 hours varied from 89 to 107 °C. Described experiment was used for calculation of the heat pump factor. , _A _ _A heat received by the convectors 3 hrs x 30kW heat pump factor = = = 9.09 consumed el. power from the mains 9.9 kWh

During the experiment the achieved heat pump factor was almost 10. This means that the heat transfer using the heat convectors is good.

Example 2

Heat transfer was provided by heating unit 4, which transfers the heat into the water used for heating the water radiators anywhere in the house. The heating circuit advantageously includes a check valve K) and a pressure gauge ϋ.

The measurement was performed for the period of 5 hours, during this period the following values were obtained:

Amount of water which passed through the exchanger during the measured period m -

347 kg Supplied electric power E = 7.9 kWh

Temperature difference at input and output from the heating unit 4 during the measured period was 51.253 °K

Specific capacity of water c = 4180 J.kg^"1 .K^"1

Consumed energy Q = m x c x delta temperature

_ Q heat consumed by water during the measured period heat pump factor = — =

E consumed electric power

4180x 51.253 x 347 „ „ = = 2.61

7900 x 3600

During the experiment with heat transfer via the heat exchanger the reached results were not as good as during the experiment with heat transfer via gas convectors.

Example 3

During the measurement 8 heating units 4 - convector radiators - were used. The connection corresponded to the fig. 2. Temperatures were measured by digital contact thermometer in five minutes intervals within one hour. AU piping is made of copper tubes. The internal diameter of the operating medium line 2 is 8 mm. The internal diameter of the operating medium return line 5 is 8 mm, downstream the throttle device 6 the internal diameter of the return line 5 and of the first cooling coil 7 is 6 mm. The internal diameter of the second cooling coil 8_. is 12 mm and the internal section of the input 13 to the compressor I is 22 mm.

At point 23 the operating medium line 2 is divided into two branches with measuring points 24, 25, 26 and 27 at inputs to the heating units 4 and at outputs 41, 42 from the heating units 4. At point 51 the branches of the operating medium return line 5_ are joined again together. Other measuring points are the point 52 upstream of the throttle device 6 and the point 53 downstream the throttle device 6.

Other measuring points are the point 54 downstream of the first cooling coil 7 and the point 55 at the input 13. to the compressor L

Initial temperature was 24 °C.

During the first five minutes the temperature at point 21 at the compressor I delivery rose up to 71 °C and then it was ranging around 90 °C. Also at point 23 the temperature at the inputs to the heating units 4 was ranging from 75 to 85 °C. The temperature at the outputs from the heating units was ranging from 38 to 40 °C. At points 51, 52 and 53 the temperature was ranging from 38 to 41 ⁰C. At point 54 the temperature was 37 °C and at point 55 it was ranging from 39 to 43 °C. Electrical power consumption was 1.8 kWh, the amount of delivered heat was 32 kWh. The heat pump factor in this case is 17.78.

Industrial Applicability

Heating using the heating system according to the invention may be applied in any space where electrical power supply is available to feed the compressor.

The system is suitable in particular for heating apartments, family houses, industrial and agricultural objects. In a portable form it is also suitable for local heating of kiosk cabins and as an additional heating source for any kind of spaces. This system may also be used for cooling of all the above-mentioned objects as well. Overview of Reference Marks.

1) Compressor

2) Operating medium line (downstream the operating medium delivery from the compressor)

3) Circulation pump

4) Heating unit

5) Operating medium return line

6) Throttle device 7) First cooling coil

8) Second cooling coil (wound around the compressor body to provide cooling of the compressor)

9) Gas filter

10) Check valve 11) Pressure gauge

12) Pressure equalizer

13) Input (of the operating medium) to the compressor

Claims

7 Patent Claims

1. A heating system characterized by the fact that at least one heating circuit of the system consists of a compressor (1) with its delivery connected to the operating medium line (2) with the internal diameter of the metal tube of 3 to 70 mm; to the operating medium line (2) at least one heating unit (4) is connected and its delivery is connected to the operating medium return line (5); the operating medium return line (5) includes at least one throttle device (6), first cooling coil (7) with identical or smaller internal tube diameter than the operating medium line (2) followed by second cooling coil (8), which is connected to the operating medium pressure equalizer (12) and its delivery is connected to the input (13) of the compressor (1); and the operating medium is a gas selected from a group formed by fluorine, helium, ammonia, freon or their mixtures.

2. A heating system according to the claim 1 characterized by the fact that the operating medium return line's (5) tube diameter is advantageously identical or smaller than the internal diameter of the operating medium line (2).

3. A heating system according to the claims 1 and 2 characterized by the fact that the throttle device (6) is formed by a nozzle or a throttle valve.

4. A heating system according to the claims 1 to 3 characterized by the fact that the operating medium line (2), the operating medium return line (5) and both the first cooling coil (7) and the second cooling coil (8) are made of copper tubes.

5. A heating system according to the claims 1 to 4 characterized by the fact that the operating medium line (2) includes a circulation pump (3) situated downstream from the compressor (1).

6. A heating system according to the claims 1 to 5 characterized by the fact that the heating circuit includes a gas filter (9).

7. A heating system according to the claims 1 to 6 characterized by the fact that the heating circuit includes at least one check valve (10) and a pressure gauge (11).

8. A heating system according to the claims 1 to 7 characterized by the fact that it includes multiple interconnected heating circuits.