DE3019475A1 - Combined solar heating system and heat pump - circulates hot air through evaporator coils circulating two heat exchange fluids - Google Patents

Abstract

The central heating system combining a heat pump with solar heating, uses a multiple path evaporator (15) with two sets of tubes (20,21) for two different heat exchanger fluids. Hot air (14) from the solar heating system (11) is blown through the evaporator. The heat pump has a circuit with an evaporator (16) through which liquid is circulated, connected by an absorber (18) or compressor to a condenser. The two fluids are highly and low vapourised respectively. The two sections of the first evaporator (15) are controlled by two way valves so that the second evaporator (16) can be used in series or parallel, and the circuit can be used in a wide variety of operating conditions, which can be controlled by a programmer (62). The highly vapourised fluid can also be used as the heat storage medium and can be passed through second evaporator.

Description

System for heat recovery from solar or ambient energy

The invention relates to a system for heat recovery from solar or. Ambient energy using a heat pump coupled to at least one air collector, in which the Heat energy exchange takes place via a multiple evaporator register, and with a heat energy store, which has a Highly evaporating heat exchange rather medium both with the multiple evaporation register as well as is coupled to the heat pump.

In addition to obtaining heat from direct solar radiation, it is also known to use a heat pump to extract indirectly stored solar energy from the ambient heat in the air by raising the ambient heat to a usable temperature level via the heat pump. In this context, it is also common to connect the heat pump to a multiple evaporator register in order to recover the desired thermal energy not only from the ambient heat, but also from waste heat. In such systems it is known to have both Fs / ai exposed

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exposed heat exchanger surfaces, which are known under the term energy roof or energy facade, od "^ transparent to use covered absorber surfaces in the form of air collectors to heat the environment and in particular the ambient air revoke. Especially when using transparent covers

■ Air collectors have shown that even in winter the energy supply from the ambient air and the light radiation can be very high, so that the air supplied to the evaporator of the heat pump above or near the heating flow temperature.

Such a favorable energy supply can also be used to heat a solar storage tank or a domestic hot water storage tank. at An optimization of such a solar system is desirable in such a way that, with increasing heat supply, that for utilization The additional energy required for the thermal energy is as small as possible. The heat should be used in such a way that that the operation of the heat pump is in the most favorable range of the coefficient of performance.

The invention is therefore based on the object of a system for generating heat from solar or ambient energy using a To create a heat pump, in which the energy supply from the ambient atmosphere and solar radiation for so long is used directly, as it directly covers the heat requirement or the storage requirement at the required target temperature level is able and for which only the immediately necessary additional energy requirement, if the temperature level is higher than the directly achievable level that is covered by the heat pump.

This task

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This object is achieved according to the invention for the system mentioned at the beginning solved in that the multiple evaporator register consists of a lamellar evaporator surrounded by air and an optionally parallel to it or in series-connected liquid-flushed evaporator is built that the lamellar evaporator two through the common Fins parallel to each other running pipe system for different heat exchange media has that the two pipe system The Lam eilenverdampf he s each with an inserted Two-way faucet into a total flow range and a partial flow range can be subdivided, the sections through which the heat exchanger medium flows in partial flow operation spatially one behind the other and / or are arranged in parallel or partially parallel in the air flow that one pipe system of the lamellar evaporator is a highly evaporating one and the other pipe system of the Lame Ilen vaporizer a low-evaporating heat exchanger medium leads, and that in the liquid-flushed evaporator for partial flow operation the high-evaporating heat exchanger medium can be switched on parallel to the low-evaporating heat exchanger medium on the heat pump is.

By the measure according to the invention it is possible in an advantageous manner, the system for heat recovery in principle to use three different operating modes, the first operating mode when there is an abundant supply of energy from the ambient atmosphere with relatively high temperatures only the highly evaporating heat exchange medium for heat transport is used directly in the solar storage tank or the domestic hot water storage tank or heating, whereas with a medium one Energy supply initially with the highly evaporating heat exchanger medium only a partial heat extraction without a heat pump and then a further heat extraction via the heat

pump

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pump takes place to eventually at a relatively low level Heat supply the heat generation via the heat pump with the low-evaporating heat exchanger medium to operate. The efficiency can be ensured by drawing energy from the solar storage tank in parallel or to keep the coefficient of performance of the heat pump in a favorable range. For this purpose, according to a further embodiment provided that the highly evaporating heat exchanger medium is also the storage medium and that the Storage medium can be switched directly to the liquid-flushed evaporator.

To even with a low heat supply from the surrounding atmosphere to be able to use this either alone or in addition to the supply from the solar storage tank is also provided, that the pipe system for the low-evaporating heat exchanger medium Can be switched to the heat pump directly or in series with the liquid-flushed evaporator via a two-way tap is.

The advantages and features of the invention also emerge from the following description of an exemplary embodiment in FIG Connection with the claims and the one-figure drawing showing the functional diagram of the system represents according to the invention.

In the drawing, one is laid on a rafter 10 Air collector 11 indicated, in which a transparent cover over a dark-colored heat exchanger surface 13 is attached. Through the space between the

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Heat exchanger surface 12 and the transparent cover 13 and optionally also behind the heat exchanger surface 12 an air stream 14 is guided, which is collected at the upper end of the air collector and fed to a lamellar evaporator 15 will. Due to the common use of air collectors large heat exchanger surface 12 and the greenhouse effect behind the transparent cover 13 can be with a such an air collector achieve relatively high air temperatures, especially when exposed to direct sunlight.

The temperature of the air stream 14 can even in winter at relatively low outside temperatures and a direct Solar radiation can reach values that are in the order of magnitude of the flow temperature of a heating system.

The lamellar evaporator 15 through which air flows, together with an evaporator 16 through which liquid flows, forms the multiple evaporator register the heat pump 17. The heat pump further comprises a compressor or absorber 18 as well a liquid-flushed condenser 19.

The lamellar evaporator 15 consists of a pipe system for the low-evaporating heat exchange medium and • a pipe system 21 for the high-evaporating heat exchange medium. The two pipe systems run parallel to each other through common lamellas and are from the air stream 14 washes around. The two pipe systems 20 and 21 are each in a central area on a two-way cock 22 or 23 connected, with the help of which it is possible in each case to convert the associated pipe system into a total flow path and to subdivide a partial flow path. at

the

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the position of the two-way cock 22 or 23 shown in the drawing, the total flow path »is switched on.

The pipe system 20 for the low-evaporating heat exchanger medium is connected to the heat pump 17 via connecting lines 25 and 26, with a branch line from the two-way valve 22 leads to connecting line 25. The connection line 25 is connected via a further two-way valve 28, which is connected to the compressor 18 a connection either via a heat exchanger coil 29 in the liquid-flushed evaporator 16 or via a stub 30 can produce. At the outset, the compressor 18 is rather snake 32 in the liquid-flushed area via a heat exchanger Capacitor 19 is connected to the connecting line 26, which is also connected to the two-way cock 28 via a branch line 33 connected.

Depending on the position of the two-way cock 22, either the total flow path of the pipe system 20 between the connecting lines 25 and 26 or a partial flow path between the connecting line 26 and the branch line 27 is switched on.

Correspondingly, the pipe system 21 is also connected to connecting lines 40 and 41 and via the two-way valve 23 to a branch line 42 connected.

The system also includes a solar accumulator 45, which is connected on the one hand to a collecting line 46 leading to the equalizing tank 47 and on the other hand is connected to a first three-way valve 48. This three-way valve 48 protrudes with a connection the connection line 40 with the pipe system 21 of the lamellar evaporator

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Evaporator 15 in connection, the other connecting line 41 as well as the branch line 42 via a first circulating pump 49 is led to the manifold 46.

The third connection of the first three-way valve 48 is connected to a second three-way valve 50, the second connection thereof leads to the liquid-flushed evaporator 16, which is connected to the collecting line 46 via a second circulating pump 51 is.

The third connection of the second three-way valve 50 is connected to a third three-way valve 53. The second connection this third three-way valve is connected to the collecting line 46 via the condenser 19 and a third circulating pump 54. From the third connection of the third three-way valve 53 there is a connection to the fourth three-way valve 55, via its second Optionally, an additional heater 56 can be connected to the manifold 46. The third connection of this fourth three-way valve 55 is located on the one hand via a heat exchanger coil in the domestic water storage tank 57 and a fourth circulation pump 58 on the manifold 46. On the other hand, the third connection of the fourth three-way valve 55 is connected to a four-way valve 60, the second connection of which is located on the manifold 46 and an underfloor heating system between its third and fourth connection or radiator heating 61 is switched.

The entire system is controlled by a controller 62 which, with a large number of thermal sensors 63, controls the respective Temperature conditions taps in order from it according to a predetermined Program controlling the circulation pumps, des

Ver

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Compressor as well as the three-way valves and the four-way valve and also the two-way cocks and the various drive motors derive. The system is controlled according to the heat demand and the amount of energy produced, whereby basically the following operating states can be switched on:

1. Direct solar heating

Due to a high level of solar radiation, the air flow 14 assumes a temperature which is sufficiently above the flow temperature the heater so that the heater can be operated immediately. For this purpose, the Total flow path of the pipe system 21 via the connecting lines 40 and 41 as well as the first, second, third and fourth three-way valve connected to the four-way valve 60, so that the highly evaporating heat exchange medium from the pipe system 21 directly via the heater 61 to the collecting line 46 can flow, from where it is circulated with the first circulation pump 49 via the pipe system 21. As the rest If the circulation pumps are not switched on, the desired circulation is obtained.

2. Direct solar hot water preparation In the event that the temperature of the air flow 14 for the Domestic water heating is sufficiently high, the pipe system 21 is with the entire flow path over the connecting lines 40 and 41 fed directly to the water heater. For this purpose, the three-way valves 48, 50, 53 and 55 switched to continuity and the circulation pumps 49 and 58 put into operation. This turns it into a fin evaporator heated highly evaporating heat exchange medium directly

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passed through the heat exchanger coil 59 of the domestic hot water tank 57 and heated the domestic water.

3. Store heat in the solar storage tank.

The operating status of the heat storage in the solar storage tank can be divided into three different operating modes: a) Heat storage in the solar storage tank via the highly evaporating heat exchanger medium.
In this operating mode, the pipe system 21 is connected to the solar storage unit via the connection lines 40 and 41 as well as the first three-way valve 48 and the first circulation pump 49, and the thermal energy obtained from the heated air stream 14 is stored. This mode of direct heat transfer with the help of the highly evaporating Wärmet au shear medium can be used as long as the temperature in the memory is about 6 to 10 below the temperature of the heated heat exchanger medium. Essentially, only the energy required to drive the fans and the circulating pump is required to operate the system.

b) Heat storage in the solar storage unit via the high-evaporating and low-evaporating heat exchange medium. This operating mode is recommended when the temperature of the air stream 14 is relatively high and so is the heat storage device is already heated to a relatively high temperature, for example 30. Since in this case that via the pipe system If the heat exchanger medium flowing back has the same temperature as the solar storage tank, the air flow cannot fall below it Temperature are cooled and would be lost with a relatively high proportion of heat energy. For this reason is activated in this operating mode with the help of the two-way valve 23

only

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only the upper partial flow path of the pipe system 21 for the circulation of the highly evaporating heat exchanger medium switched on in order to take part of the thermal energy from the air flow 14 directly, whereas the residual heat in the air flow 14 via the second pipe system 20 with the low-evaporating heat exchange medium via the heat pump is withdrawn. The pipe system 20 can either have the entire flow path or also a partial flow path be connected to the heat pump by the two-way valve 22, the lower partial flow path over the Branch line 27 connects to the heat pump, the heat exchanger medium via the two-way valve 28 and the Branch line 30 is led directly to the compressor 18. The heat exchanger medium flows from the outlet of the compressor 18 Via the condenser 19 and the connecting line 26 back to the pipe system 20. The thermal energy obtained by the heat pump is from the condenser 19 via the third three-way valve 53, the second three-way valve 50 and the first three-way valve 51 as well as the collecting line 46 and the third circulation pump 54 transported into the solar storage 45 in order to use the thermal energy share obtained by the heat pump keep heating up.

c) Heat storage in the solar storage tank via the low-evaporating Heat exchange medium.

In this operating mode, the heat pump is connected to the solar storage tank and in the manner described under operating mode b) the lamellar evaporator 15 connected, the low evaporating heat exchanger medium is circulated over the entire flow path of the pipe system 20. The circulation of the highly evaporating heat exchange medium via the

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Pipe system 21 is interrupted by switching off the first circulation pump 49.

4. Heating with the heat pump

There are essentially four modes of operation in this operating state of interest:

a) Heating from the solar storage tank with the heat pump.

In this operating mode, the heat pump is stored in the solar thermal system

45 from via the first three-way valve 48 and the second three-way valve 50 supplied with the highly evaporating heat exchanger medium, which in the liquid-flushed evaporator 16 flows around the heat exchanger coil 29 and the one flowing in the heat pump low-evaporating heat exchanger medium is heated. From evaporator 16, the high-evaporating heat exchanger medium

• j ^ g medium via the second circulation pump 51 and the collecting line

46 returned to the solar storage tank 45. By appropriately setting the two-way cock 28, the branch line 33 with To connect the heat exchanger coil 29, the low-evaporating heat exchanger medium in a small circle over the Evaporator 16 and the condenser 19 circulates. The highly evaporating heat exchanger medium heated in the condenser 19 is thereby used circulated through the heater 61 to give off heat. This circulation path runs through the third three-way valve 53, the fourth three-way valve 55, the four-way valve 60, the heater 61 as well as the collecting line 46 and the third circulation pump 54.

b) Solar heating via a heat pump at low air temperatures.

In this operating state, the air collector 11 still delivers sufficient thermal energy via the air stream 14 to be able to use the low

evaporating

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evaporating heat exchanger medium and the heat pump to obtain the necessary flow temperature for the heater 61. The heat pump is thereby connected to the total flow path of the pipe system 20 in the lamellar evaporator 15 the two-way cock 28 and the branch line 30 connected.

On the output side of the heat pump, the highly evaporating Heat exchanger medium circulates in the heating circuit as in operating mode 4a). This mode of operation is preferably used at relatively lower temperatures of the air stream 14 use, the heat pump operated up to the limit of economic use can be.

c) Solar heating using a heat pump at high air temperatures. This operating mode is intended to be used when there is a sufficiently high level of solar radiation and thus a relatively high temperature First of all, part of the thermal energy is withdrawn directly from the air flow via the highly evaporating heat exchange medium Heater 61 are supplied. This is followed by a flow of air from the cooled but still relatively warm air stream further heat extraction via the heat pump. For this purpose, the highly evaporating heat exchange medium is the upper Partial flow path of the pipe system 21 over the with the Branch line 42 connected two-way valve 23 and the connecting line 40 circulates via the heater 61. To this The purpose is the connection line 40 via the first three-way valve 48, the second three-way valve 50, the third three-way valve 53, the fourth three-way valve 55, the four-way valve 60 connected to the heater 61, from which the return flow of the heat exchange medium Via the four-way valve 60, the collecting line 46 and

3Q the first circulating pump 49 to the branch line 42 takes place. The im

Air-

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The partial flow path of the pipe system 21 spatially upstream of the air flow is the partial flow path of the pipe system 20 downstream between the two-way valve 22 and the connecting line 26, so that the air flow, which is part of his Heat energy transferred to the highly evaporating heat exchange medium, the remaining part to the low can continue to give off evaporating heat exchanger medium. This partial flow path of the pipe system 20 is about Branch line 27, the two-way valve 28 and the branch line 30 are connected to the compressor 18 of the heat pump and is Recirculated via the heat exchanger coil 32 and the connection line 26 to the lamellar evaporator. At the same time will by operating the third circulating pump 54, the highly evaporating heat exchange medium also passes through the condenser 19 circulates to the heater 61 in order to supply the residual heat obtained by the heat pump to the heater. This circulation takes place from the condenser 19 via the third three-way valve 53, the fourth three-way valve 55, d.as four-way valve 60, the Heater 61 and the collecting line 46 as well as the third circulating pump 54 back to the condenser 19. In this operating mode the circuit of the low-evaporating heat exchanger medium has the task of removing the residual heat up to the limit of the To withdraw economical use of the lamellar evaporator 15.

d) Solar heating via heat pump from air flow and storage.

At relatively low air temperatures it is desirable to operate the heat pump with a favorable coefficient of performance anyway. To this end, the aerial electricity, the economically removable heat is extracted and the heat pump is supplied with additional heat from the storage tank, so that

she

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it can be operated economically. In this operating mode, the capacitor 19 is via the third three-way valve 53, the fourth three-way valve 55, the four-way valve 60 connected to the heater 61, the return via the collecting line 46 and the third circulation pump 54 takes place. On the evaporator side, the heat pump is on the one hand over the entire flow path of the pipe system 20 with the low-evaporating heat exchange medium to the lamellar evaporator 15 and on the other hand connected via the heat exchanger coil 29 to the solar memory 55. To this end, the Two-way cock 28, the connection line 25 with the heat exchanger coil 29. The heat exchanger coil 29 is in the liquid-flushed evaporator 16 from the highly evaporating heat exchanger medium from the solar storage tank 45 flows around, which via the first three-way valve 48, the second three-way valve 50 and the second circulation pump 51 via the solar storage 45 is circulated. This operating mode of the system allows even at relatively low Temperature of the air stream 14 a good efficiency the heat pump as long as heat can still be extracted from the solar storage tank.

By adapting the operating status of the system in accordance with the invention, an optimization with the possibility of a minimum additional energy consumption is possible, namely by using the energy available from the ambient air and solar radiation as long as possible directly as long as heat extraction is possible without significant additional energy. By providing the regulator 62 the individual operating modes according to the

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by the temperature sensor scanned temperature values are automatically switched on, so that the adjustment of the optimal operating mode to the prevailing temperature conditions is possible at any time. The control of the system via the controller 62 takes place on the basis of known control sequences, with setpoint values being specified in a memory, which the controller compares with actual values and controls the system accordingly. (Process computer)

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Claims (3)

Patent claims l.J System for heat recovery from solar or ambient energy using at least one air collector coupled heat pump, in which the heat energy exchange takes place via a multiple evaporator register, and with a heat accumulator, which has a highly evaporating heat exchange medium with both the multiple evaporator register and is coupled to the heat pump, characterized in that -that the multiple evaporator register consists of an air-circulated lamellar evaporator (15) and an optional one liquid-flushed evaporator (16) connected in parallel or in series is constructed, - That the lamellar evaporator (15) has two pipe systems (20, 21) running parallel to one another through common lamellas for different heat exchanger media, - That the two pipe systems (20, 21) of the lamellar evaporator (15) each with an inserted two-way cock (22, 23) in a total flow path and a partial flow path can be subdivided, with the heat exchanger medium flowing through them Sections in partial flow operation spatially behind - 130048 / 04U - 2 - MS4P-2121 each other and / or parallel or partially parallel in the air flow (14) are arranged, - That one pipe system (20) of the lamellar evaporator (15) a low-evaporating heat exchanger medium leads, and the other pipe system (21) of the fin evaporator (15) carries a highly evaporating heat transfer medium, - And that in the liquid-flushed evaporator (16) for the partial flow operation, the highly evaporating heat exchanges rather medium parallel to the low-evaporation heat, it is more medium can be switched to the heat pump (17). 2. System according to claim 1, characterized in that - That the highly evaporating heat exchange medium is also the storage medium, and - That the storage medium is flushed directly on the liquid Evaporator (16) is switchable. 3. System according to claim 1 or 2, characterized in that - That the pipe system (20) for the low-evaporating heat exchange medium Via a two-way tap (28) directly or in series with the liquid-flushed evaporator (16) on the heat pump is switchable. 130048 / 04U