DE19740398C2 - Combined heat and power facility for energy supply - Google Patents

Abstract

The invention relates to a combined heat and power device for heating, cooling and for supplying electrical energy to buildings and facilities. DOLLAR A Known solutions have the overall disadvantage that they do not offer complex solutions for the aforementioned purposes and use the available regenerative energies only insufficiently with a substantial reduction in primary energy use. DOLLAR A The invention remedies this deficiency by means of an electronically controlled, complex device which ensures reliable, efficient heating, cooling and electrical energy supply in summer and winter operation with the lowest use of primary energy. DOLLAR A core of the device are an internal combustion engine 1, a generator 2 and a heat store 4, to which an additional store 6 is assigned. Both stores are connected to each other by a heat pump 3, the additional store 6 serving as a heat source for the heat pump 3. Plant modules that generate thermal energy with a relatively high thermal level are connected to the heat accumulator 4 and those modules that supply thermal energy with a relatively low thermal level are connected to the additional memory 6.

Description

The invention relates to a combined heat and power Establishment of small to medium power to the Ener energy supply for private and / or public Buildings and facilities using primary energy from liquid or gaseous fuels, preferably natural gas, according to the preamble of Claim 1.

There are already numerous from the state of the art Plants and facilities for the energy supply of Buildings with heat and electrical energy and for cleaning known for hot domestic water. The for the Heating, including hot water preparation, Kli automation and power generation of buildings Most plants are separated from one another installed and operated. That inevitably has Consequence that both the investment and the Operating costs, especially for those to be used Primary energies are high.  

DE 42 03 491 A1 describes an electronically controlled one Power supply unit known for generating of heat and electrical energy. The energy supply unit includes a generator for the Electricity generation from an internal combustion engine is driven. The thermal energy is generated from the Exhausting the engine and the cooling water from the burner engine obtained by means of heat exchanger and in provided a boiler. With the help of a heat pump pe, which is driven by the internal combustion engine, residual heat is recovered from the engine exhaust and used for heating the boiler. The Boiler may also be generated by the electrical energy can be heated. The energy ver care unit according to DE 42 03 491 A1 has none Equipment for air conditioning of buildings and Heat recovery from the exhaust air. Regenerative Energies are not used.

A similar heating and power plant for Conversion of primary energy and ambient heat into electrical energy and useful heat beats the DE 40 06 742 A1. The centerpiece of the system is a with a burner operated boiler and one with the same burner heated Stirling engine, one Generator and a heat pump drives. The generator is preferably a linear generator, which has a appropriate control with the drive motor one Heat pump, with the public power grid or with other consumers can be electrically connected can. With the help of the heat pump, heat is also increased recovered from the ambient heat and for Heating purposes provided. A subsystem for Air conditioning of buildings and facilities and Recovery of thermal energy from the air conditioning systems does not provide for this solution proposal.  

A combined system for the production of electrical devices gie using the waste heat from the Hausstromer Generation for space heating is from DE 44 34 831 A1 known. The electrical energy is with a gas mo Tor generator arrangement generated, with a Waste heat recovery pipeline as a heat source working heat exchanger to the gas engine genera gate arrangement is connected. In the source side a heat transfer medium is heated and the steam thus formed transfers the heat exchangers to the room heating supplied. The liquefied steam flows in closing after releasing its thermal energy into the source-side heat exchanger of the gas engine genera gate arrangement back. According to a preferred embodiment This system is also an absorption cooler direction provided in a circulation pipe is involved. The circulation pipeline is with a Gas-liquid phase changes in heat medium filled. There is heat at this circulation pipe exchanger connected to cool buildings serve undocking. The disadvantage of this facility again is that the facility has no funds for the use of renewable energies.

From DE 41 02 636 A1 it is also known that in a Combined heat and power plant with the help of a genera tors generated electrical energy in a battery to buffer. In addition to greater independence from public energy supply networks are supposed to this measure reduces the operating times of the system adorns and the in-house supply of electrical Energy better adapted to the respective needs can be. The proposed facility, the same in time for the supply of hot domestic water and with Heating is used, works exclusively with electrical energy as primary energy use and has none further equipment for the use of renewable energy  gien and for heat storage. Particularly disadvantageous it can be seen that larger amounts of heat in Spit stress times occur, not exploited and must be released to protect the system.

A proposal to integrate solar collectors in a heating system that uses fossil primary energy is operated is known from DE 26 19 744 C2. The proposed heating system is also with a Liquid heat storage and equipped with heat pumps steadily in order to achieve the highest possible efficient use the heat generated by solar and primary energy to reach. The generated by the solar collectors Thermal energy is used as much as possible in this plant used only for heating purposes. A further groove of solar energy, for example in the season in which the sunlight is not as strong and the use of further renewable energies does not provide this facility.

The invention has for its object an elek tronically controllable device of the beginning genus for heating, cooling and energy supply including buildings and facilities to develop renewable energies with relatively low cost and investment costs rea and the necessary share of primary energy for the heat and energy supply further redu graces.

According to the invention, the task is characterized by the claim 1 specified features solved. Beneficial Further developments of the invention result from the Claims 2 to 11.  

Known per se with the coupling according to the invention Basic modules and their specially coordinated combination a completely new quality in Utilization of the primary energy used has been achieved, the system according to the invention at the same time Heating, for producing hot domestic water and for Air conditioning (cooling) of buildings used can be. The invention therefore does not constitute a supplement expansion or expansion of known combined heat and power systems, but a new type, perfect standalone and environmentally friendly solution that is extremely economical. In its entirety, it unites the complex functions Heating, electricity generation, hot water generation supply and cooling with efficient use of regenerati ver environmental energies.

The system according to the invention for the winter Generation of heat and electrical energy from fossil Energy sources, such as gas or oil, is used for climatization in summer of buildings and facilities and for maintenance warm hot water at the same time Power generation. So there are no additional ones Air conditioning costs necessary in summer dig, which only corresponds to the project planning appropriate dimensions of the heating surfaces visible during the summer operation as Serve cooling surfaces.

The system according to the invention can effizi anywhere there ent used and thus the primary energy consumption be reduced where currently conventional Gas, oil or solid fuel heaters are installed.  

The centerpiece of the combined heat and power plant The device is connected to a heat accumulator with an additional storage to hold heat gie with a relatively low thermal level with an internal combustion engine that has a power generator drives with a heat pump, which is optionally available as Compression or absorption heat pump trained is, with solar devices for exploitation regenerati ver energies and with facilities to exploit the waste heat generated when using primary energy, which are also connected to the additional storage, connected is.

By using the two memories, ent speaking dimensioning of the overall system the Be number of hours of the engine designed so be that with proper maintenance a top possible service life without problems with standard machines is achieved. The use of special and therefore expensive internal combustion engines that are for permanent use drive must be designed, are therefore not required. By integrating the heat pumps location it is even possible for this application an inexpensive air-cooled fuel machine use because the cylinder and housing waste heat usable into the storage system can. The system according to the invention temperature and dew point control is secured by the application of a efficient, electronic control exploitation of renewable energies. The run time of combined heat and power facilities and the consumption of primary energies can result from the Energy storage is reduced to a minimum the.  

The one in the internal combustion engine that is coupled with a generator for generating electrical energy is used and serves to drive the heat pump, generated heat, is burned via the cooling system engine at different thermal levels fed to both memories. With the help of heat transfer the exhaust gases, the cooling water and the Engine oil of the internal combustion engine on thermally relative high level, some of the residual heat is removed and used further charging of the heat accumulator coupled.

With the help of a condensing condenser, the be already cooled exhaust gases further residual heat finally the heat of condensation due to the Calorific value effect removed and the additional storage fed relatively low thermal level.

According to an essential feature of the invention Internal combustion engine generator unit in a soundproof and thermally insulated housing thermally encapsulated. The waste heat generated in the housing is removed by an air-water heat exchanger at thermally low also copied into the additional memory according to level pelt and can therefore be used. This Energies serve as a source for the heat pump.

The invention is almost complete Use of the waste heat from the system ensures what the Combined heat and power plant (CHP) principle, including the Use of the condensing effect corresponds.

Via the additional storage tank to which a recooler is connected Heat recovery from a ventilation system Building, a heat exchanger for the exploitation of the Waste water residual heat and during winter operation the solar collectors are also connected on the primary side are with the heat pump that heat the  thermally connects to the additional storage, Thermal energy from the environment, which is a relatively low own level, exploited and with a higher level thermal level in the heat accumulator for preparation hot water for heating and for warm Process water fed. Due to the system the use of the heat pump the effectiveness of the inventions cogeneration device according to the invention increased to the extent that more usable heat and electrical power is provided as the one set primary energy includes.

This effect results from the coupling of the Interaction of environmental energy from the solar systems with the heat pump.

The invention is intended to be an embodiment example will be explained in more detail. The Associated Drawing shows a schematic representation of the Cogeneration heating, cooling and Power supply facility.

As can be seen from the drawing, the primary energy used for heating, for air conditioning (cooling), for generating electrical energy and for hot domestic water, in the present exemplary embodiment preferably natural gas, in a manner known per se of an internal combustion engine 1 , for example a gas engine or Turbine fed, which drives a generator 2 for generating electrical energy. Internal combustion engine 1 and generator 2 are housed in a sound and heat insulated housing 36 , which with a supply for supply and exhaust air 37 ; 38 is equipped for cooling purposes.

To the generator 2 , which drives the heat pump 3 , the house network 34 for the electrical power supply and the public e-network are connected via the e-network connection 32 . The connection to the public E-network is made with the interposition of meter units 15 for the purchase and for the recovery / supply of electrical energy.

The generator 2 is preferably designed as Asynchronmaschi ne, which is rigidly connected to the internal combustion engine 1 . This variant offers the advantage that the generator is used as a drive to start the internal combustion engine 1 and at the same time there is no need for complex network synchronizations. A so-called soft start circuit may be necessary for generators with high power. The use of synchronous or direct current generators is of course possible and makes sense, among other things, if an island operating mode of the electrical energy supply system is desired.

After the starting process, the internal combustion engine 1 runs up at the nominal speed of the motor in accordance with the mains frequency present. When the internal combustion engine is loaded by increasing the primary energy supply, the generator 2 is over-synchronized, and current is fed into the connected network. The load on the internal combustion engine can be controlled by measuring the power so that the generator works with its specified nominal power. This condition forms the nominal operating point for the generation of electrical energy and waste heat.

If 34 electrical energy is consumed in the house network connected in parallel during generator operation, the energy is supplied directly by generator 2 and does not have to be taken from the public electrical network for a fee. By using the heat accumulator 4 , the running time of the device for generating electrical energy can be controlled so that it always works when the electrical energy consumption in the building or in the public network is given.

In principle, instead of the engine genes rator unit also the use of a fuel cell possible without the downstream systems parts and active principles thereby change significantly other.

Due to the intermittent operation of the system according to the invention, it is useful and economical to temporarily store the electrical energy generated. According to the present embodiment, the alternating current generated by the generator 2 is rectified in a battery charger and supplied to a battery system integrated into the photovoltaic system 16 , in which electrical energy is stored. The electrical energy stored in this way for self-consumption is fed by the inverter as an AC voltage via the E-mains connection 33 and the switching device 40 into the house network 34 . In addition, the photovoltaic system 16 is connected to the battery system and via this battery system to the public electrical network.

The solar panels included in the photovoltaic system 16 supplement the use with regenerative energy in a known manner.

In addition to the known use of a Wärmespei chers 4 , an additional additional storage 6 is part of the combined heat and power device according to the invention. This additional storage 6 serves on the one hand as a heat supplier for the evaporator of the heat pump 3 in the heating mode during winter operation and as a cooling water supplier in the cooling mode when operating the air conditioning of the buildings in summer.

During the winter operation, the solar collectors 13 , the condensing condenser 42 and the cooling system 10 of the internal combustion engine 1 and the generator 2 are connected to the additional storage 6 , which is connected to the heat storage 4 via the heat pump 3, on the primary side by means of the lines 5 .

In addition, a heat exchanger for utilizing the waste heat from the exhaust air recooling 27 of the building is also ruled out to the additional storage 6 . All of the aforementioned modules supply thermal energy with a relatively lower thermal level to the additional store 6 , which forms the thermal energy source for the heat pump 3 .

In addition, there is a heat exchanger in the additional storage 6 with a waste water waste heat recovery 20 , which naturally has a waste water connection 19 and an overflow 31 for the sewer system, and via the valve 11 for the selectable changeover to summer and winter operation with the underfloor heating 28 and the heating / Heatsinks 29 connected to the building. The additional store 6 is also advantageously equipped with a connection 7 for a further cooling circuit.

At the heat accumulator 4 , which is preferably designed as a layer tens storage, the exhaust system of the internal combustion engine 1 and in summer operation the solar collectors 13 are connected to its charging with thermal energy through the connecting lines 8 pri. Through the connecting lines 45 , the oil cooler of the internal combustion engine 1 is connected to connection lines 8 and thus directly coupled to the heat accumulator 4 . The condenser of the heat pump 3 serves as a further heat source for the heat accumulator 4 .

An alternative heat generating device in the form of a conventional gas burner 39 (redundancy) complements the system according to the invention.

On the secondary side of the heat accumulator 4 via a mixer 18, the lead 21 of the Heizungsin installations, which during cooling operation at the same time resp. Serve air conditioning, and the lines for the hot water connection 25 is closed.

The flow 21 of the heating installations is connected to the auxiliary storage 6 on the secondary side during the summer operation for the air conditioning of the rooms, to which the recooling 27 for heat recovery from the exhaust air of the building is connected in winter operation. The changeover to summer and winter operation is carried out with the help of the changeover valves 11 ; 12 and the valves 41 ; 42 and 43 realized, which are all controlled with the help of the electronic control unit 9 .

For the eventual accident at the Brennkraftmaschi ne 1 has as an alternative heat generating means in the exhaust passage of the internal combustion engine 1, the operational one exhaust stream switch 35 to summer and winter, a gas burner 39 is provided, which directly contact with exhaust gas heat exchanger 24 for charging the heat accumulator 4 via the connecting lines 8 are connected to it.

On the secondary side to the heat accumulator 4 connected mixer 18 is carried out in a special way, the outside temperature controlled regulation of the Heizungsvor run 21st Contrary to the general method, the mixer 18 is operated not only with three, but with several connection points. These are the input side of the hot water connection from the upper area of the heat accumulator 4 , the hot water connection from the central area of the heat accumulator 4 and the return 14 of the heating system, and the outlet 21 of the heating system flow. With the help of the electronic control unit 9 , the automatic switchover between the input lines for regulating the flow temperature takes place. So at Vorlauftem temperatures up to the average temperature of the heat accumulator 4 of the heating / cooling flow 21 in the middle memory area in conjunction with the cooler return 14 is operated. If the setpoint of the outside temperature-controlled control is above the temperature in the storage medium region, the admixture from the return 14 is interrupted. The admixture then takes place from the upper area of the heat accumulator 4 with hot water. This special arrangement of the input currents for the mixer 18 minimizes the consumption of hot water and thus greatly reduces the system start-ups for recharging the heat accumulator 4 . This effect directly benefits the life of the internal combustion engine 1 .

The return 14 of the heating installation is fed to the heat accumulator 4 at the lowest point and in this way supports the thermal stratification in the accumulator 4 . In order to achieve the lowest possible return temperatures, according to the invention in the heating / cooling return 14 of the building, for example, a floor or panel heating 28 and a preheater 26 for heating the inflowing fresh air of the ventilation system are arranged.

Within the heat accumulator 4 , heat exchangers are provided, by which the hot service water in the lower part of the heat accumulator 4 , which, as described above, is preferably designed as a stratified accumulator, is preheated. On the one hand, the desired cooling of the heat accumulator 4 is supported in this storage area and at the same time the heat removal in the upper hotter storage area is minimized. A downstream simple thermal mixer 30 is used to set the desired end temperature of the treated hot water.

A major advantage of the combined heat and power device according to the invention is that the proposed system can be used effectively for heating purposes and during the summer operation for air conditioning / cooling of the buildings and facilities without additional equipment or plant-side changes in the cold seasons. In summer operation, the medium (water) located in the additional storage 6 is cooled down to approximately 0 ° C. using the heat pump 3 . This cold water is via switch valves 11 ; 12 fed to the mixer 18 for the cooling operation in summer and for the heating operation in winter and mixed to a temperature a little above the dew point of the air in the rooms to be cooled and via the cooling / heating surfaces 29 and possibly the floor heating 28 to the corresponding rooms led to cooling. It is done by the existing Heizan location, the cooling of the rooms without additional plant-side expenses are required. Existing ventilation and air conditioning systems are integrated into this cycle accordingly.

Another advantage is that when an absorption machine is used as the heat pump 3, the heat energy transported in the summer by the solar collectors 13 into the heat accumulator 4 can be used for cooling. The energy source of the absorption refrigerator is then the charged heat accumulator 4 .

The solar collectors 13 integrated in the device according to the invention fulfill two tasks. Due to the direct connection of the solar collectors 13 with the heat accumulator 4 , the solar energy in summer is used directly for the preparation of hot domestic water and, if necessary, for the preparation of warm water for heating purposes. This arrangement corresponds to the well-known classic application of solar systems in a temperature range above 50 ° C.

Especially in the colder season, however, the solar energy is generally no longer sufficient to heat the heat transfer medium of the solar collectors 13 to the desired temperature level of over 50 ° C. In conventional systems, the collectors are only partially used in the winter period.

In the device according to the invention, with the help of the heat pump 3 in conjunction with the additional storage 6 collector flow temperatures of the solar collectors 13 of substantially less than 50 ° C. can be used efficiently all year round by the relatively low temperature level of the solar collectors 13 in the colder years, the colder years Heat transfer medium in Zusatzspei 6 is supplied via a heat exchanger. As a result, heat is transported at a relatively low temperature level from the environment into the additional memory 6 . With the help of the heat pump 3 , this heat energy is raised to a usable thermal level of approximately 50 ° C. and supplied to the heat accumulator 4 , as already described. This makes it largely possible to dispense with other environmental heat suppliers for the operation of the heat pump 3 , as is the case with, for example, classic heat pump systems for utilizing thermal energy from geothermal, water or air heat with a correspondingly high level of apparatus and thus financial outlay. The device according to the invention differs fundamentally from known plants and systems and at the same time minimizes the plant-side effort by consistently using the solar collectors 13 in both summer and winter. The changeover to summer and winter operation is in turn carried out with the aid of the changeover valves 22 ; 23 made.

Reference list

1

Internal combustion engine

2nd

generator

3rd

Heat pump

4th

Heat storage

5

management

6

Additional storage

7

Connection for further cooling circuit

8th

Connecting cable

9

electronic control unit

10th

cooler

11

Diverter valve

12th

Diverter valve

13

Solar collector

14

Rewind

15

Counter unit

16

Photovoltaic system

17th

-

18th

mixer

19th

Sewer pipe

20th

Wastewater buffer

21

Heating / cooling flow

22

Diverter valve

23

Diverter valve

24th

Exhaust gas heat exchanger

25th

Process water connection

26

Supply air preheating

27

Exhaust air recooling

28

Underfloor heating

29

Heating / cooling surfaces

30th

Domestic hot water thermostat

31

Wastewater overflow

32

E-mains connection

33

E-mains connection

34

House connection

35

Exhaust gas flow switch

36

Enclosure

37

Supply air

38

Exhaust air

39

Gas burner

40

Switching device

41

Valve

42

Condensing condenser

43

Valve

44

Valve

45

Connecting cable

Claims (11)

1. Combined heat and power facility for heating, cooling and energy supply of buildings and facilities using fossil primary energy and using solar energy consisting of an internal combustion engine and a generator driven by it, which serves to operate a heat pump and with the house network building the public Ver and supply network for supplying electrical power is connected and one arranged in the exhaust passage of the internal combustion engine, heat exchanger, which is connected together with a solar collector primärsei tig to a heat storage, which are connected to thermal energy and hot water to be supplied building equipment on the secondary side with, characterized That the heat accumulator ( 4 ) an additional storage ( 6 ) is assigned and both storage ( 4 ; 6 ) via a heat pump ( 3 ) are thermally coupled with each other, system modules, the heat energy with a relatively high thermal N generate level, are connected to the heat accumulator ( 4 ) and system modules that provide thermal energy with a lower rigorous thermal level to the additional storage ( 6 ), which serves as a heat source for the heat pump ( 3 ). 2. Device according to claim 1, characterized in that the exhaust system of the internal combustion engine ( 1 ), the cooling system ( 10 ) of the internal combustion engine ( 1 ) and generator ( 2 ) and in summer the solar collectors ( 13 ), primarily on the side Heat storage ( 4 ) and system modules ( 20 ; 27 ; 42 ) for the recovery and recovery of thermal energy from the building exhaust air, the water and during winter operation from the solar collectors ( 13 ) and the cooling system ( 10 ) of the internal combustion engine ( 1 ) and the generator ( 2 ) are connected on the primary side to the additional storage ( 6 ). 3. Device according to claim 1 and 2, characterized in that the heat accumulator ( 4 ) and the additional storage ( 6 ) are stratified storage. 4. Device according to claim 1 and 2, characterized in that in the exhaust line of the internal combustion engine ( 1 ) as an alternative heat generation device, a gas burner ( 39 ) which is directly coupled to the primary side of the heat accumulator ( 4 ), and an exhaust gas flow switch ( 35 ) are intended for summer and winter operation. 5. Device according to claim 1 and 2, characterized in that the waste water line (19) connected to the building at a sewage temporary storage (20) and the memory (20) is connected to a heat exchanger in the additional memory (6). 6. Device according to claim 1 and 2, characterized in that a supply air preheater ( 26 ) for conditioning the supply air of the ventilation system ge of the building in the return ( 14 ) of the heating / cooling installations ( 29 ; 28 ) is coupled. 7. Device according to claim 1 and 2, characterized in that an exhaust air recooling ( 27 ) is integrated in the ventilation system of the building and is thermally coupled to the additional memory ( 6 ). 8. Device according to claim 1, 2 and 7, characterized in that in the heating / cooling flow ( 21 ) a mixer ( 18 ) turned on and the mixer ( 18 ) on the input side of the heat accumulator ( 4 ), each with a connection in Upper and middle area of the heat accumulator ( 4 ), the return ( 14 ) of the heating / cooling installations ( 28 ; 29 ) and the exhaust air recooling ( 27 ) of the building are connected. 9. Device according to one of claims 1 to 8, characterized in that the changeover to summer or winter operation by Umschaltventi le ( 11 ; 12 ; 22 ; 23 ), the connections in the line connections of the respective system modules for hot or additional storage ( 4th ; 6 ) are provided and the exhaust gas flow switchover ( 35 ) takes place and the valves ( 11 ; 12 ; 22 ; 23 ) and the switchover ( 35 ) can be controlled via the electronic control unit ( 9 ). 10. Device according to one of claims 1 to 8, characterized in that the changeover to the heating or cooling mode is carried out by the switching valves ( 11 ; 12 ;) and valves ( 41 ; 43 ; 44 ) which are operated via the mixer ( 18 ) are switched on in the heating and cooling flow ( 21 ), the valves ( 41 ; 43 ) and the changeover valve ( 12 ) with the heat accumulator ( 4 ), the valve ( 44 ) with the return flow ( 14 ) and the exhaust air recooling ( 27 ) and the switching valve ( 11 ) with the additional storage ( 6 ) and the exhaust air recooling ( 27 ) are connected. 11. Device according to one of claims 1 to 10, characterized in that the internal combustion engine ( 1 ) and the generator ( 2 ) are replaced by a fuel cell with an electronic inverter.