DE2620395A1 - Heat economiser for oil fired central heating - includes heat pump at flue with water coil housed under roof tiles - Google Patents

Abstract

The central heating system has e.g. an oil fired boiler which includes a heat recovery arrangement with a blower in the flue gas outlet line discharging the gases through an exhaust hose bent into a U shape, with a heat exchanger coil around it. Another branch also includes a blower for discharge or collection from outside. The coil forms part of a heat pump with an evaporator and a compressor and a water circulation system which can consist of a set of pipes in the form of a zig-zag coil housed under the roof tiles. This enables the heat of the sun on the tiles to be used to obtain extra efficiency for the system.

Description

Heat recovery system

The invention relates to a heat recovery system with which the Heat loss in the exhaust gases, as well as the radiation losses from central heating boilers with fossil fuels and the energy content of the outside air as well as the energy, that is supplied to the roof cladding of buildings by solar radiation, in terms of heat for heating and hot water preparation purposes with operating temperatures up to 900, should be made usable.

In addition, this invention is intended to reduce the impact on the environment during operation from central heating boilers with fossil fuels.

A heat recovery system that has the required properties can, among other things, with great advantage in the flue gas line, as well as in the heating circuit of Central heating boilers. The heating circuit is preferably with a Heat exchangers for hot water preparation coupled, also thought with special cleaning including an air flow from the outside air, as well as that from the boiler room and a water cycle, the is routed under the roof cladding of buildings, with the heat recovery system geuppe't ground.

When running central heating boilers, there is an interest in that Utilize energy supply to a large extent and according to the limited availability the conventional energy carriers of fossil origin, through locally available energy carriers such as electrical energy, solar energy and the outside air, as much as possible to replace it on an economic basis. One gains the advantage that such Central heating boilers with heating water preparation devices the so far on an annual average with a Coefficient of performance, based on the upper calorific value Ho of approx.

1: o, 75 can be operated through the use of the heat recovery system, according to of the invention operated with a total annual performance figure of approximately 1: 1.2 could become. The increase in the COP from 1: 0.75 to approx. 1: 1.2 of Central heating boilers with hot water facilities in connection with the Heat recovery system, according to the invention, is achieved by the conventional Heat loss from the exhaust gases, as well as that of the radiation from central heating boilers, is heat-efficient be used. Utilization of the heat loss is still in operation with the previous ones existing central heating boilers not possible and with the new ones to be developed only with an effort that is not economically justifiable.

through the use of the heat recovery system, according to the invention would be an exploitation of the energy, the exhaust gases and the jet losses both from in located in the gearbox as well as from new central heating boilers to be built with heating water preparation devices possible with economic means.

The total coefficient of performance is approximately 1 z 1.2 of central heating boilers with Hot water facilities would be achieved by reducing the heat dissipation of the exhaust gases as well as the central heating boilers can be used with approx. 25% and in addition, 30 of the annual heat demand of residential buildings by utilizing the energy content the outside air or that of the roof cladding of buildings, which is affected by the sun is supplied, is covered.

The use of the energy content of the outside air, as well as the solar energy content the roof skin mainly relates to the period from April to September.

The heat recovery system according to the invention would be on average to operate with an annual performance figure of 1: 5, this would have a 20% result in electrical energy requirements. According to this, 1/5 would be electrical energy for the heat recovery of 55% of the annual heat demand one 0 1/5 of 55% 11 0 55% from 11% = 33% = 44 o energy gain / a The heat recovery system according to the invention works on the principle of a Heat pump and is designed according to the invention so that in one or more Heat exchangers are installed in the tanks, which are removed from the exhaust gases of the central heating boiler, from an inside and outside air flow, as well as from a water circuit which is preferably is guided below the roof skin, can be flowed through. The energy flows are here brought into connection with the evaporator of the heat pump circuit in such a way that the energy content of up to +20 can be extracted from the energy carriers flowing through can.

The energy withdrawals are made possible by inside an evaporator, which has contact with the energy carrier circuits, a refrigerant for evaporation is brought and thus enabled energy up to a temperature range of approx. + 20. The evaporated refrigerant is energized an iompressers in a condensation vessel, which is in contact with the central heating boiler return and the hot water heater has liquefied again - with condensation heat up to 9oD accrues and here to the return of the central heating boiler and to the service hot water supply is delivered.

By cooling the exhaust gases from approx. + 2000, the dew point becomes the Exhaust gas fell short of and the moisture content of the exhaust gas, as well as large parts of the Environmentally harmful substances (such as sulfur etc.) precipitate in the heat exchanger and could be fed from here to a collecting tank by means of an ondensate line, stored and fed to a processing plant for clarification.

This would be an economical alternative to conventional desulphurisation achievable from heating oils. The condensate that occurs when operating gas boilers could be diverted directly into the public sewer system, as in this condensate its harmful substances such as sulfur etc are contained.

An embodiment of the invention is shown below at the edge of the Drawings Big. 1 and 2 described, change in schematic, not to scale Representations show a heat recovery system according to the invention.

The heat recovery system, which is labeled 1 in FIG Central heating boiler shows whose exhaust gases with the exhaust fan 23, which is designated with 2 Heat exchanger, which is preferably made of stainless steel, fed will. The exhaust gas flow is air from the boiler room via the draft control flap 24 supplied. The exhaust fan 23 is preferably with the central heating boiler burner 30 electrically coupled.

The heat exchanger 2 can also be connected to the fan 22 via the air pipe system 20 and 25, an air stream of the outside air and the inside air are supplied. The blower 22 is preferably connected to the electric thermostat 26, which controls the indoor air temperature samples and the thermostat 27, which samples the outside air simultaneously with the electrically controllable air duct flaps 21 and 28 with adjustable temperature range controlled.

In the heat exchanger 2 of the heat pump circuit, the energy sources, such as the exhaust gas, the indoor and outdoor air flow, through contact with the evaporator 6, the energy taken up to approx. +20. With this energy extraction cool down the energy carriers down to + 2 °. Here the dew point is undershot and condensate precipitates in the heat exchanger 2.

The condensate is drawn through the condensate line 38 into the condensate collector 5 headed. Yon here can the condensate from oil heating a clarification, and that from gas heating systems with drain 3, are fed to the public sewage system. By collecting the condensate in the condensate collector 5 and clarifying it would be particularly useful when running central heating boilers on fossil fuels achieved a considerable environmental relief with heating oil. With the condensate would namely among other things, the sulfur content of the heating oil is largely kept away from the environment. Some of the substances contained in the condensate could be reused as raw materials The heat pump circuit is powered by the electrically driven compressor 13, in which this the energetic refrigerant via line 33 from the evaporator 6 is sucked in and compressed in the condensation vessel 10 so that a heat of condensation up to + 90 ° is actuated.

The condensation heat is transferred from the condensation vessel 10 to the water reserve 34 of the central heating boiler return and to the useful hot water reserve 11 with cold water supply line 9, as well as with the hot water outlet 12. The energy supply of the condensation vessel 10 to the water reserve 34 of the Zentralheizungsiesselrückclaufes is scanned with the thermal sensor 35 and in the electrical control part 36 with the outside temperature, which is sampled with the thermal sensor 37, compared and in the priority switching, compared to the burner switch-on 30 taken into account. The power supply to the iJmpressor 13 is with the thermostat 15 that the temperature the water reserve 34 of the central heating boiler return covered, controlled. The evaporator 6 is preferably the first after the controllable reducing valve 7 contact with the heat exchanger 4 of the water circuit 31, which is preferably below the roof skin of a building and is operated with the circulation pump 32.

The circulation pump 32 is preferably connected to the thermostat 27 that the outside temperature is scanned, switched. Second is the evaporator 6 preferably with the heat exchanger 2, through which the exhaust gases from the central heating boiler. as well as an air flow of the outside and inside air is guided contact.

The exhaust gas, the outside air and the inside air flow 19 from the heat exchanger 2 exits, is preferably heated with the heat exchanger 18 so that it falls below the dew point outside the heat exchanger 2 can be excluded. The energy to The central heating boiler circuit is used to heat the exhaust gas, the outside and inside air flow 14 removed and controlled with the adjustable thermostatic valve 17.

The heating circuit 41 is controlled with the mixer 40.

To clean the heat exchanger 2, preferably during each the downtime of the central heating boiler burner 30 should occur, becomes a Condensate circuit, to which a solvent is preferably added, proposed. The condensate circuit is preferably made up of the condensate collector 5, the heat exchanger 2 and formed from the line 16.

The actuation of the condensate circuit during the standstill period of the central heating boiler burner 30 is preferably carried out with the circulation pump 39.

The water circuit 31 according to FIG. 1 is preferably composed of a multi-tube Formed line, which is designed in its shape according to Figure 2 so that a multi-tube line 1 with the half-shell 2 according to Figure 2 in the cavity between the Dachletten 6 the rafters 7 and the roof covering 8 takes place. The multi-tube Line 1 is preferably supported in the half-shell 2 by supports 3. The half-shell 2 has the task of ensuring that the multi-tube line 1 is flushed with air. With the air circulation should form condensation, exclusively on the multi-tube line 1, are limited. The half-shell 2 is so in their Manufacture shaping that they the Sondensat, which is located on the multi-tube Line 1 knocks down, pick up and ride over the pool cover 8, can dissipate.

The multi-tube line 1 with half-shell 2 according to Figure 2 is preferred made of temperature-resistant plastic as running meter goods. With help the end pieces i, the multi-tube line 1 with half-shell 2 and the hose connection 5, the closed water pipe system 31 according to FIG. 1 could be produced by gluing Through the end piece recess 4, within the water pipe system 31 the waterways 11 are given so that an optimal route and sojiit one A sufficient residence time for the water to absorb energy in the roof area is achieved will. An anti-frustration agent is preferably added to the water. The water cycle is preferably actuated by the circulation pump 32 according to FIG.

Patent claims:

Claims (1)

Claims: 1. On the basis of a heat pump working heat recovery system in particular a heat recovery system with which, among other things, the energy content of the exhaust gases as well as the radiation losses from central heating boilers with fossil fuels, the energy content of the outside and inside air and the energy content of the roof cladding, which this is mainly supplied by solar radiation, heat-economically for Operating temperatures + 90 ° can be made usable0 2. Heat recovery system according to claim 1, characterized in that the heat exchanger 2, according to Fig.1 with the exhaust gas fan 23 the exhaust gas of the central heating boiler 1 and a proportion of indoor air, controlled thereby the flap 24, is fed and through the connection with the Evaporator c, the energy content of the exhaust gas and the internal air in the boiler room and for heating and hot water heating purposes with operating temperatures up to + 900 can be made usable. 3. Heat recovery system according to claim 1, characterized in that that preferably the heat exchanger 2 according to FIG. 1, with the fan 22, an air stream the outside air, as well as the inside air, and its energy content through the connection with the evaporator 6 removed and for heating and hot water purposes can be made usable with operating temperatures up to + 600. 4. Heat recovery system according to claim 1, characterized in that the heat exchanger 2 with a manually controllable or automatically controllable Cleaning system is equipped. 5. Heat recovery system according to claim 1, characterized in that that the heat pump circuit, according to Figure 1 for heat exchange between the 5. Heat exchangers 2, 4 and the water reserve 34 Ges central heating circuit 14 which is coupled with the domestic hot water heater, with the eleXtronic-mechanical Control 7, 8 according to Figure 1 can be controlled so that the ibgas the outside and inside air flow 19, which flows through the heat exchanger 2, can always be used. 6. Heat recovery system according to claim 1, characterized in that that the central heating boiler burner 30 according to Figure 1 with the electronic priority circuit 36 for the heat recovery system is monitored depending on the outside temperature by the outside temperature with the thermocouple 37 and the temperature of the central heating return 34 scanned with the thermal sensor 35 and so in the electronic control part 36 be compared that the specified temperature setpoint of the heating return must be fallen below before the central heating boiler burner is switched on 30 can be done. 7. Heat recovery system according to claim 1, characterized in that inter alia a second heat exchanger 4 through which a water circuit, which is preferably is guided below the roof membrane, is connected to the evaporator U so, that the water circuit with the same evaporator 6 the thermal energy up to + 2 can be taken. 8, heat recovery system according to claim 1, characterized in that when utilizing the energy content dep exhaust gases from central heating boilers with fossil fuels Fuels in particular with heating oil, an environmental benefit is achieved that one Desulphurization of the heating oil is equivalent. @. Heat recovery system according to claim 1, characterized in that that the water cycle is preferably carried out under the roof cladding of buildings will, after wig. 2 from a multi-tube line surrounded by a half-shell 2 is, is made. 10. heat recovery system according to claim 1, characterized in that daX the multi-tube line 1 with half-shell 2 according to FIG. 2 in its profiling as follows it is chosen that it is between the roof battens 6 of the roof skin 8 and the rafters 7 can be installed in buildings without any structural changes. 11. arm recovery system according to claim 1, characterized in that that the half-shell 2 according to FIG. 2, the multi-tube line, due to the spacer supports 3, encloses in such a way that condensation only occurs on the multi-tube line 1 is limited, and that the condensate is collected in the half-shell 2 and with the Line 10 can be discharged onto the roof skin 8. 12. Heat recovery system according to claim 1, characterized in that that the multi-tube line 1 with half-shell 2 according to Figure 2 as running meter goods made forth and through the end pieces 9 with Ausaparrungen 4 by means of gluing a pipe system that ensures sufficient contact and retention time for the medium, that is intended for energy transmission is ensured. 13. Heat recovery system according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12, that with the combined heat recovery system according to Fig.1 and 2 an economic basis for a partial exchange of energy carriers against a 13. Material and wage-intensive economic goods formed can be. 14. Heat recovery system according to claim 1, 2, 3, 4, 5, 6, 7, 8, i, 10, 11, and 12, which is shown schematically in Figs. 1 and 2, thereby marked, that with economically justifiable means in the operating and the newly created central heating systems can be installed. 15. Heat recovery system according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14 according to FIGS. 1 and 2, characterized in that the annual Coefficient of performance of new central heating boilers to be built and those in operation, based on the upper calorific value with fossil fuels from 1: o.75 to over Can be increased 1: 1.