DE19927027C1 - Heat production arrangement from environmental energies, having solar collector, heat swapper, heat pump, and fluid storages which are connected selectively to assure energetically most favorable arrangement - Google Patents

Abstract

The arrangement includes a heat pump (2) connected at its evaporator side with a fluid storage (3) with low temperature level, and on the condenser side with a fluid storage (4) with regulated, high temperature level, at which heat consumers are connected. The fluid storages are mutually connected to thermal overheat convertors. A solar collector (1) can be connected alternatively with respectively one of the fluid storages. A heat convertor (5) can be connected in series with the solar collector, whereby a temperature of the collector is lifted to environmental temperature level. Pumps (9,10) and valves (7, 8, 25) are controlled in such way through a selection control, that the respective energetically most favorable arrangement of the components is activated.

Description

The invention relates to an arrangement of devices for generating heat from environmental earth gien according to the preamble of claim 1 at a temperature level which is technical can be sensibly achieved with a heat pump. The level is, for example, approx. 60 ° C. The application is particularly on building heating and domestic water heating thought, but the heat can also be used for industrial processes.

The devices used for the arrangement are solar collector, heat pump, hot / cold water storage, heat exchanger and temperature difference controller. The individual components are all known and available in bulk on the market. The type of arrangement is new. In addition, microprocessor technology and new methods of building insulation open up Applications of the invention that were previously unrealistic. The aim is one sensible compromise between equipment expenditure and good energy yield.

The usual use of solar collectors is the arrangement with the optimal position for radiation direction of the sun, the flow through a heat transfer medium when measuring a useful radiation and storage of heat in a water tank. With known furnishings This type has been found to be disadvantageous in that the radiation energy of the sun is day is subject to temporal, seasonal and climatic fluctuations, and that the Collector output not only from the radiation, but also from the difference between Collector temperature and ambient temperature depends. This also has excellent isolation Collectors as a result that in Central European climate with low radiation and ge moderate temperature mostly results in a very poor collector efficiency. Such an Orders are therefore usually only used to support a sun-independent warmth water preparation, more rarely also space heating.

The usual use of heat pumps is the supply of heat on the evaporator side by Beaufschla with ambient air, water from lakes, rivers or groundwater, or with geothermal energy. The Use of water and in particular geothermal energy with relatively uniform temperatures  of over 0 ° C offer favorable conditions for the use of heat pumps because the Lei heat pump from the temperature difference from evaporator to condenser is pending. But only the ambient air, whose temperature is subject to large fluctuations is usable everywhere and without great expenditure on equipment. Lakes and rivers are usually not in in the immediate vicinity and even if not used without permission; Groundwater can only be reached via a fountain - also only with permission; is the warmth of the earth can only be used after extensive earthwork using buried heat exchanger surfaces.

The invention has for its object the uses of heat pumps and To significantly improve solar collector by coupling the same to each other in that one device enables the other device and vice versa, in operating areas with to work better efficiency or better coefficient of performance.

The solution is achieved by integrating the known components in a control and regulation concept according to claim 1. Advantageous developments of the arrangement are specified in the subclaims. The arrangement according to the invention has the following advantages:

• - By lowering the temperature level in the collector via the heat pump, the Use of only little solar radiation is possible because heat losses are reduced the. This makes the ratio of "more necessary for the manufacture of the collector Energy "to" gain solar energy in the collector "compared to conventional one set of collectors greatly improved. The collector can therefore be used all year round not only when the outside temperature is high enough.
• - When the heat transfer fluid is cooled appropriately by the heat pump, Raising the fluid temperature to ambient temperature using a collector upstream heat exchanger and through further solar heating in the collector reached the highest possible temperature level at the evaporator of the heat pump. In order to the operating conditions for the heat pump in more energetically favorable areas placed.  
• - The upstream heat exchanger is used for cooling if the solar radiation is too strong used so that the harmful high downtime temperatures of the collectors avoided become. When the heat exchanger is installed with a medium with a high thermal conductivity Heat storage capacity, e.g. B. the earth, can with excessive radiation stored heat in operating states with higher heat demand via the Heat pump can be recovered.
• - The invention enables the conservation of energy resources and the minimization of CO ₂ and pollutant emissions during heat generation.
• - The control described heat generation is fully automated, so that proven heat generators (furnaces or electricity) can be substituted.
• - Commercial components from inexpensive mass production can be used become.
• - The container provided in heat pump operation as a storage for cold fluid can can also be used as a heat store without additional equipment, if over there is excess heat energy, which increases the total storage capacity.
• - The possibility of direct use of radiation energy with sufficient solar Irradiation without interposing the heat pump is fully retained.

The arrangement described captures the availability of environmental energies, taking into account changes in climatic, seasonal and time of day. For this, the solar collector optionally with a storage tank with a high temperature level, namely with the level of the target or process temperature (this memory also represents the condenser side of the heat pump, and here the heat consumers are connected) or with a storage tank with a lower one Temperature level (this storage also represents the evaporator side of the heat pump) connected. The storage tanks are also thermally connected to each other via heat exchangers, so that the temperature levels can be adjusted. The memory comes the Task to, by sufficient dimensioning fluctuations in the time of day To be able to bridge radiation intensity. This is also the approach taken by the patent application  EP 00 54 729 A1. In the device described there, however, is disadvantageous in that Activation of the "second heat transfer fluid channel", which ultimately only functions as a heat exchanger has radiation energy that is collected by the "first heat transfer fluid channel" Ambient temperature level is pulled down and thus remains unused. The Heat yield is therefore far from optimal. It is also heat carrier fluid channel around a special construction and is therefore expensive to manufacture. Therefore the facility described in the aforementioned application has not become established.

The disadvantage mentioned is not optimal use of solar radiation and the use of special constructions is avoided in this patent application in that in the event that the Temperature in the storage tank with a low temperature level is below the ambient temperature and the outlet temperature of the solar collector is below the desired process temperature, The solar collector is optionally preceded by a heat exchanger, which is used to cool the cold ren storage fluid circulated can be raised to ambient temperature. Thereby heat losses in the collector are reduced to a minimum and solar radiation is optimal used. All components are available as merchandise. This basically also applies to the required temperature difference controller, which, however, makes sense in a special Control unit should be summarized to the number of required, expensive tempera to minimize door sensors. In order to be able to make optimal use of solar radiation, there is a switch scheme and a control concept necessary, which are described below. To the temperature of ambient air, cold storage and hot storage continuously measured and compared and by means of temperature difference controllers Valves and pumps controlled. A selection control system selects the cheapest arrangement activated.

Further advantages of the invention result from the following description and the drawing.

• 1. The / the solar collector (s ) 1 is supplied via pump 9 and channel 16, a heat transfer fluid, which is heated in the solar collector. Via channel 18 , the fluid arrives at a switching valve 8 , from where the fluid either flows via channel 20 to the fluid reservoir 4 , which is kept at least at process temperature, or via channel 19 to the fluid reservoir 3 . The pump 9 is switched on by means of the temperature difference controller 21 when a higher temperature is measured at the collector outlet by means of the sensor 12 than at the fluid reservoir 3 by means of the sensor 14 . It is then always possible to use solar or environmental energy.
• 2. If the solar radiation is not sufficient to keep the fluid reservoir 4 directly at the process temperature, the heat pump 2 is switched on. In this case, thermal energy from fluid reservoir 3 (evaporator side of the heat pump) is raised to the temperature level of fluid reservoir 4 (condenser side of the heat pump). As a result, fluid storage 3 is extracted from thermal energy. When the heat pump is in operation, the heat transfer fluid coming from the collector 1 is always conducted at the changeover valve 8 via the fluid channel 19 through the fluid reservoir 3 . In this operating mode, the temperature in the fluid reservoir 3 may drop until an equilibrium between heat supplied as solar radiation or environmental energy and heat dissipated to the heat pump is reached. As the difference between fluid temperature and outside temperature is reduced, the efficiency of the collector increases continuously.
• 3. The fluid is then passed to the temperature difference controller 22 controlled switching valve 8 via channel 19 through the fluid reservoir 3 when it is heated in the collector 1 only to a temperature below the temperature measured in the fluid reservoir 4 by means of the sensor 15 or in the fluid reservoir 4 by means of Sensor 15 a temperature is measured above the permissible maximum temperature, see also 6. In the fluid reservoir 3 , the fluid emits heat and flows back to the pump 9 and from there via the fluid channel 16, depending on the position of the valves 7 and 25, either directly into the collector or via heat exchanger 5 in the collector or only through the heat exchanger.
• 4. The fluid is then passed to the collector by the temperature difference controller 23 controlled switching valve 7 via the fluid channel 17 through the heat exchanger 5 when the fluid in the fluid reservoir 3 has cooled to a temperature below the ambient temperature measured by the sensor 13 and the switching valve 8 is switched to the fluid channel 19 or if the permissible maximum temperature is exceeded in fluid memory 3 . In this case, heat is not achieved with heat exchanger 5 , but rather cooling. This avoids the very high temperatures which are detrimental to the service life of the collector and occur when the collector is at a standstill. The fluid is then passed directly to the collector bypassing the heat exchanger 5 when the temperature in the fluid reservoir 3 is above the ambient temperature and the permissible maximum temperature in the fluid reservoir 3 is not exceeded. The collector 1 is bypassed by means of valve 25 if heat loss due to radiation into the environment would occur at the collector.
• 5. The fluid is then passed to the changeover valve 8 via channel 20 through the fluid reservoir 4 when it is heated in the collector 1 to a temperature above the temperature measured by means of the sensor 15 in the fluid reservoir 4 , but below an adjustable maximum temperature, and the heat pump is not is switched on. The fluid emits heat in the fluid reservoir 4 and flows back to the pump 9 and from there via the fluid channel 16 directly back into the collector. This corresponds to the usual use of solar collectors.
• 6. The fluid is then directed to the temperature difference controller 22 controlled switching valve 8 via channel 19 through the fluid reservoir 3 when a temperature above the permissible maximum temperature is measured in the fluid reservoir 4 by means of a sensor 15 . Fluid storage 4 is then fully charged and fluid storage 3 can be used as an additional storage for directly solar generated heat that can be used without a heat pump as long as the process temperature is not fallen below.
• 7. The fluid is then circulated by means of pump 10 between the fluid reservoir 3 and fluid storage 4 for temperature equalization when in fluid storage 4, a lower temperature is as measured by temperature sensor 14 in fluid reservoir 3 by means of differential temperature controller 24 by means of Tempera turfühler 15th This is the case when fluid storage 4 takes more thermal energy than is supplied via collector 1 . The fluid then absorbs heat in the fluid reservoir 3 and releases it again in the fluid reservoir 4 . Of fluid reservoir 3, therefore, the memory capacity in the range of the difference of the maximum temperature can be (z. B. 70 ° C) and process temperature (eg., 40 ° C) for direct use, and fluid reservoir 4 can be the storage capacity in the range of the difference of maximum temperature (e.g. 100 ° C) and process temperature directly and indirectly in the range of process temperature and minimum temperature at the heat pump condenser (e.g. -15 ° C) via the heat pump. This means that the storage capacity is more than doubled compared to the usual use of solar collectors, thus relativizing the disadvantage of a second storage device.

An advantageous embodiment of the invention is specified in claim 3 and relates to the selection of the cheapest switching point of the fluid flow from the collector to storage 3 or storage 4th The temperature at the collector outlet measured by sensor 12 depends, among other things, on the collector inlet temperature and the radiation power. With constant irradiation power, it is therefore a difference whether the collector is charged with heat transfer fluid from the colder storage 3 or from the warmer storage 4 . It can occur operating conditions with moderate irradiation, in which the temperature of fluid storage 3 is raised until shortly before reaching the process temperature, although it could be switched to storage 4 beforehand if the collector with the higher temperature level from storage 4 would be hit . However, priority loading by the solar collector of fluid reservoir 4 is always desired, since this temperature level can be used directly. This can be achieved by continuously comparing the temperature measuring points 12 , 14 and 15 and continuously calculating when the switch from valve 8 to fluid channel 20 for loading fluid reservoir 4 is possible at the earliest. The dependency of the collector efficiency on the collector temperature and ambient temperature can be stored in a computer and taken into account when calculating the switchover point.

A further advantageous embodiment of the invention is specified in patent claim 4 and relates to the choice of the heat exchanger 5 . The lowest installation effort results when using a heat exchanger arranged in the ambient air. If the heat exchanger is arranged in such a way that the heat transfer fluid stores in heat-conducting contact with large rainwater, with the groundwater indirectly with the ground or directly with the ground (so-called ground collectors), the heat capacity can be decentralized in the case described under 4. large storage tanks or the ground are used and the stored heat can be recovered at a later time via the heat pump.

A further advantageous embodiment of the invention is specified in claim 5 and relates to the defrosting of the heat exchanger 5 which is required regularly if the heat exchanger 5 uses the ambient air and the temperature of the heat transfer fluid falls below the freezing point of the air humidity. Defrosting is achieved by switching valve 7 for a short time to the heat exchanger flow and valve 8 to channel 20 , even if the above-mentioned conditions for optimal energy generation are not present. For this period of time, the heat exchanger is flowed through with heat transfer fluid heated in fluid reservoir 4 . No additional equipment is required.

A further advantageous embodiment of the invention is specified in claim 6 and concerns the execution of the temperature difference controller. Some of the same tempera Tower measuring points required for different temperature difference controllers. When using individual A separate set of temperature sensors is then required for each device. Tem temperature sensors can be saved if, instead of 4 individual devices, a central control device is used, which takes over the function of 4 individual devices.

Claims (6)

1. Arrangement for the generation of heat from solar radiation and environmental energy consisting of at least one solar collector, a heat pump, two fluid stores, temperature differential controllers and several connecting channels, valves and pumps, wherein

• a) to the solar collector (s) ( 1 ) by means of a first pump ( 9 ) via a first channel ( 16 ) a heat transfer fluid which is heated in the solar collector, from there via a second channel ( 18 ) to a first switch valve ( 8 ) and flows from here either via a third channel ( 20 ) to the first fluid reservoir ( 4 ) or via a fourth channel ( 19 ) to the second fluid reservoir ( 3 ) when a first temperature differential controller ( 21 ) at the collector outlet has a higher temperature than in detects second fluid reservoir ( 3 ),
• b) the heat pump ( 2 ), the evaporator side of which is thermally connected to the second fluid reservoir ( 3 ) and the condenser side of which is thermally connected to the first fluid reservoir ( 4 ), switched on and via the first changeover valve ( 8 ) the second channel ( 18 ) to the fourth channel ( 19 ) is connected if the temperature in the first fluid reservoir ( 4 ) falls below a pre-selectable temperature,

characterized in that a heat exchanger ( 5 ) can be connected upstream of the solar collector in the flow direction and the pumps and valves are activated by a selection control such that:

• a) the first switch valve ( 8 ) connects the second channel ( 18 ) to the fourth channel ( 19 ) when a second temperature difference controller ( 22 ) at the collector outlet detects a lower temperature than in the first fluid reservoir ( 4 ), or when in the first fluid reservoir ( 4 ) a temperature above a preselectable temperature is measured,
• b) a second switching valve ( 7 ) connects the first channel ( 16 ) to a fifth channel ( 17 ) so that the heat transfer fluid is passed through the heat exchanger ( 5 ) when a third temperature difference controller ( 23 ) in the second fluid reservoir ( 3 ) Lower temperature than detected in the environment, or if a temperature above a preselectable temperature is measured in the second fluid reservoir ( 3 ), whereas the second switch valve ( 7 ) connects the first channel ( 16 ) directly to the collector input if the conditions mentioned do not apply ,
• c) a third changeover valve ( 25 ) connects the heat exchanger ( 5 ) directly to the second channel ( 18 ) and thus bypasses the collector ( 1 ) if heat loss due to radiation from the collector would occur in the environment,
• d) the first changeover valve ( 8 ) connects the second channel ( 18 ) to the third channel ( 20 ) when the second temperature difference controller ( 22 ) detects a higher temperature at the collector outlet than in the first fluid reservoir ( 4 ) and in the first fluid reservoir ( 4 ) a temperature below a preselectable maximum temperature is measured and the heat pump ( 2 ) is not switched on,
• e) the first changeover valve ( 8 ) connects the second channel ( 18 ) to the fourth channel ( 19 ) when a temperature above a preselectable maximum temperature is measured in the first fluid reservoir ( 4 ),
• f) a second pump ( 10 ) circulates heat transfer fluid between the fluid reservoirs ( 3 and 4 ) for the purpose of temperature equalization when a fourth temperature difference controller ( 24 ) in the second fluid reservoir ( 3 ) detects a higher temperature than in the first fluid reservoir ( 4 ).

2. Arrangement according to claim 1, characterized in that the temperatures are detected by sensors ( 12 , 13 , 14 , 15 ). 3. Arrangement according to claim 2, characterized in that the measured temperatures and information about the position of the first switching valve ( 8 ) are fed to a computer which continuously calculates the solar heating power of the heat transfer fluid during operation of the first pump ( 9 ) and taking into account the collector efficiency as a function of irradiation power and outside temperature is calculated in real time, which temperature of the heat transfer fluid would be reached at the collector outlet if the second channel ( 18 ) were connected to the third channel ( 20 ), so that the first fluid reservoir ( 4 ) would be charged and whether a preselectable withdrawal rate can be reloaded with it. 4. Arrangement according to one of the preceding claims, characterized in that it is in the heat exchanger ( 5 )

• 1. a.) Air / water heat exchanger charged with outside air,
• 2. b.) Around a water / water heat exchanger charged in an underground water tank or with groundwater
• 3. c.) Or around a heat exchanger buried in the ground (earth collector)

can act. 5. Arrangement according to claim 4, characterized in that when using an air / water heat exchanger, any defrosting that may be required is achieved in that the second switching valve ( 7 ) for a preselectable period or a time determined by a closed control loop on the heat exchanger flow and the first switching valve ( 8 ) is switched to the third channel ( 20 ). 6. Arrangement according to one of the preceding claims, characterized in that the temperature difference controller ( 21 , 22 , 23 , 24 ) are combined in a control device in order to require only one sensor for each said measuring point.