DE102013003469B4 - Method for heating rooms or buildings using renewable, volatile electrical energy - Google Patents

Abstract

Method for heating rooms or buildings with at least partial use of renewable, volatile electrical energy from a generating system of such energy locally assigned to a room or building, this electrical energy being fed via a control system primarily into several electro-thermal storage units for heating the room or building and is fed subordinately into an external power grid, the electro-thermal storage if the thermal energy requirements of the electro-thermal storage or the room or building heated thereby are not sufficiently covered by the local generation system by electrical power fed externally into the room or building from an external Electricity network is supplied or co-supplied, an expected energy supply and an expected energy surplus of the local generation plant is determined, by programming parameters during the installation, by taking into account a weather forecast, by taking into account past data, and by taking into account a rhythm of the energy requirements of consumers, and an expected energy requirement of the at least one room or building is determined by updating the needs of the past, with learning cycles and/or, if the consumer is used for room heating, by analyzing the room temperature and its progression, analyzing the outside temperature and its progression, taking into account the usage times programmed in by the user and /or taking into account a weather forecast, the electro-thermal storage is at least one central storage, or a hot water or latent heat storage, and several decentralized storage, and in the event of an automatic outflow of heating energy from the electro-thermal storage into the room or building heated by it, at least the minimum and/or the maximum permissible storage temperature and/or the minimum and/or the maximum energy content of the storage, from the heat flow from the storage towards the room or building, the current heat requirement of the room or building and/or the permissible minimum and/or the maximum room or building temperature is calculated.

Description

FIELD OF THE INVENTION

The invention relates to a method with the features of claim 1. Accordingly, it is intended to use at least partially regenerative, volatile electrical energy for room or building heating, which comes from a renewable, volatile source from an electrical power generation system locally assigned to the room or building energy comes from.

TECHNOLOGICAL BACKGROUND

Various systems or concepts for generating or handling electrical and/or thermal energy in a building are described, for example, in DE 295 18 427 U1 , the EP 2 469 238 A2 , the DE 10 2010 017 277 A1 , the DE 10 2012 003 227 A1 and in the company publication “SMA SMART HOME” (SMART_HOME-KDE123611W.pdf from September 2012). Electrical energy from renewable, volatile energy sources such as solar energy or wind energy is only available intermittently. On a large scale, this deficiency is partially overcome by storing energy, for example in high-altitude water reservoirs, or by storing heat in thermally insulated mineral fills. If there is sufficient availability of renewable, volatile energy at times when the demand for electrical power is comparatively low or sufficient is provided by power plants, this excess electrical energy is used to store energy. Efficiency losses are comparatively high and efficiency optimization is difficult.

On a small scale, an incentive to set up appropriate generation systems such as photovoltaic systems is created through public funding for the decentralized supply of buildings with renewable, volatile electrical energy. If renewable, volatile energy is available and its consumption is lower in the building or building complex equipped with such a system, this excess electrical energy is fed into the general power grid.

With almost all photovoltaic (PV) systems on private houses, the feed into the public grid occurs automatically after the self-consumption is also automatically deducted. PV inverters, two-way meters and all household consumers are connected to the same house power grid. What the inverter generates and is not consumed by local consumers immediately goes into the public grid. If the inverter generates too little, the rest is automatically drawn from the public grid. The order of supply so far is as follows: first normal household consumers, then feeding into the public power grid.

Depending on the funding model, however, the remuneration for electricity fed in is lower than for electricity consumed at the same time as generation (e.g. Germany) or the remuneration for electricity fed in is significantly lower than the costs for electricity purchased externally (e.g. Austria). Furthermore, the promotion of this so-called self-consumption is intended to relieve the burden on the electricity transport network. A disadvantageous effect is that the solar energy, which is preferably used to supply buildings with electrical power and/or heat, is often available when the energy consumption in the building is comparatively low, such as during times of day when, for example, residential buildings are used by fewer people than in the morning, evening and night hours. The solar energy, which is relatively more available in the middle hours of the day, must therefore be fed into the general power grid in the form of locally generated electrical energy, with the same electrical energy being drawn from the power grid at other times to cover heating requirements.

PRESENTATION OF THE INVENTION

Based on this, the invention is based on the task of optimizing and making the room heating of the building, building complex or individual rooms accessible. To solve this problem, a method with the features of claim 1 is proposed. Accordingly, in a generic method it is provided that the energy generated regeneratively in the generating system - locally assigned to the room or building - or the surplus after supplying any other consumers within the building - is primarily divided into several electrical ones via a control system -to feed thermal storage. This electrical energy is then fed into the external power grid. The electro-thermal storage units were only supplied or co-supplied with electrical power from the external power grid fed into the room or building if the thermal energy requirements of the electro-thermal storage units were not adequately covered by the local generation system. The invention achieves, among other things, an efficient use of locally generated, renewable, volatile electrical energy for room or building heating. The feed into the general power grid and the purchase of energy from this grid is minimized, which also means the Energy storage to be kept available on the supply network can be relieved. By using the decentrally generated, renewable, volatile electrical energy in the building to which the generation system is locally assigned, in the form of thermal storage, this energy input is optimized. Thermal storage ensures a shift in energy requirements from times with little or no renewable energy yield to times when there is sufficient renewable energy yield. The preferred order of supply is: 1. normal household consumers, 2. thermal storage, 3. feeding into the grid. The types of consumers in the house are differentiated into “movable” consumers (those with storage) and “non-movable” ones (all others), even though they are connected to the same house power network.

For the purposes of the invention, “volatile” regenerative electrical energy is understood to mean regenerative energy that cannot be controlled over time, i.e. solar and wind energy, but also the power of flowing water, and from which electrical current has been generated.

• Die elektro-thermischen Speicher umfassen mindestens einen zentralen Speicher wie z.B. einen Warmwasser- oder Latentwärmespeicher, und mehrere dezentrale Speicher, wie z.B. Speicheröfen, und/oder mindestens einen Flächenheizungsspeicher, wie einen Speicherestrich und/oder ein Speicherputz umfassen. Mehrere solcher Speicher oder Speichersysteme können mit gleichen oder unterschiedlichen Leistungen, wie z.B. bei Elektrospeicheröfen, Wand- oder Bodenwärmespeichern, vorgesehen sein.

The invention can now be carried out in different ways:

• The electro-thermal storage includes at least one central storage, such as a hot water or latent heat storage, and several decentralized storage, such as storage ovens, and/or at least one surface heating storage, such as a storage screed and/or a storage plaster. Several such storage or storage systems can be provided with the same or different performances, such as in electric storage heaters, wall or floor heat storage.

The electro-thermal storage can be supplied with electrical energy by one or more electric heating elements, e.g. those for hot water. Several comparatively not too powerful heating elements, which are switched on depending on the energy supply, have proven to be advantageous.

The local generation system for electrical energy from a renewable, volatile energy source can include a photovoltaic system, a wind power or hydroelectric power system, a combined heat and power system and/or a biogas system.

Other consumers of electrical energy in the room or building can be primarily supplied with electrical energy from the locally assigned generation system by the electro-thermal storage.

The expected energy supply and/or the expected energy surplus of the local generation plant is determined. This can be done during installation by programming parameters such as nominal power, orientation and/or location factor of a photovoltaic system, and/or by taking into account a weather forecast and/or by taking into account past data, such as the daily rhythm of a photovoltaic system and/or by taking into account the rhythm of energy requirements the other consumers.

The expected energy requirements of at least one room or building are determined. This is done by updating past requirements, if necessary by learning cycles and/or, if the thermal consumer is a room heater, by analyzing the room temperature and its progression, analyzing the outside temperature and its progression, taking into account the usage times programmed in by the user and/or Taking a weather forecast into account.

In the event of an automatic outflow of heating energy from electro-thermal storage into the room or part of the building heated by them, for example in the case of a surface heating storage, the minimum and/or the maximum permissible storage temperature and/or the minimum and/or the. Maximum energy content of the storage, calculated from the heat flow from the storage towards the room, the current heat requirement of the room and/or the permissible minimum and/or the maximum room temperature. The operation of a storage heater that was actually planned for the on/off process (release only at night and 2 hours in the afternoon) gives way to a kind of buffer operation.

When using at least one heating element powered by electrical energy to heat up the electro-thermal storage, its connected load(s) can be programmed as a parameter during commissioning. The connected loads can be determined automatically through measurements during commissioning and/or during ongoing operation.

The power output of the local generation system and the power consumption of any other consumers can be determined using suitable meters or measuring devices.

The power drawn by the property from an external power grid and the power fed into the external power grid by it can be measured, in particular using a two-directional meter, such as a smart meter. One or more of the used Meters can be designed as two-tariff meters, such as the HT-NT meters currently available for secondary storage heaters.

It doesn't matter how much the generating plant produces and the other household consumers consume. What is crucial is that almost no surplus is fed into the grid because it is used for heating. A two-way meter with the corresponding counting outputs is already available in practically every house with a PV system. The task of the control is to set the grouping of the heating elements so that the energy flow via this counter is as close to 0 as possible. “Property” is understood here to mean the local generation plant and all consumers (thermal storage and other consumers) together.

The current energy content of the electro-thermal storage can be determined, in particular through measurement, constant balancing and/or similar methods.

The expected demand of the thermal consumers in a future can be calculated in advance, especially in a period that corresponds to the temporal storage capacity of the thermal storage.

The heating of the electro-thermal storage can be controlled in terms of performance and/or time, taking into account the expected time requirement and the currently available energy, so that the proportion of the energy coming from the local energy generation system in the total energy flowing into the thermal storage in a period of time is as high as possible.

When using heating elements operated with electrical energy to heat up several electro-thermal storage units, if there is a heat requirement, the heating elements can be switched on, in particular at any time, in such a grouping that their combined power consumption corresponds to the power generated by the generating system locally assigned to the room or building or, if other consumers are present, comes as close as possible to the excess power. So instead of a single connection to a very powerful heater, it is split into small connected loads that are switched on according to heat requirements and energy availability. When forming the group, the thermal energy present in the respective storage and/or the energy likely to be required in the future by the room or building (part) supplied by the respective storage can be taken into account. Predictive storage is therefore carried out according to supply and demand.

Parameterization can be used to determine whether and/or to what extent the set heating output may exceed the line supply or the excess power.

The aforementioned and the claimed components to be used according to the invention described in the exemplary embodiments are not subject to any special exceptional conditions in terms of their size, shape, material selection and technical conception, so that the selection criteria known in the field of application can be used without restriction.

Further details, features and advantages of the subject matter of the invention result from the subclaims, as well as from the following description and the associated drawing, in which - by way of example - an exemplary embodiment of an electro-thermal storage system is shown. Individual features of the claims or the embodiments can also be combined with other features of other claims and embodiments.

BRIEF DESCRIPTION OF THE FIGURES

• 1 ein allgemeines Blockschaltbild eines elektro-thermischen Speichersystems zur Nutzung regenerativer, volatiler elektrischer Energie;
• 2 ein Blockschaltbild eines elektro-thermischen Speichersystems zur Nutzung regenerativer, volatiler elektrischer Energie am Beispiel eines Einfamilienhauses mit Elektro-Speicherheizung.

Show in the drawing

• 1 a general block diagram of an electro-thermal storage system for using renewable, volatile electrical energy;
• 2 a block diagram of an electro-thermal storage system for the use of renewable, volatile electrical energy using the example of a single-family home with electric storage heating.

DETAILED DESCRIPTION OF EMBODIMENTS

The exemplary embodiments according to 1 and 2 provide a control for an electrically heated, thermal storage system in which the electrical energy is supplied to the storage in a controlled manner. Depending on requirements, heat is supplied to the thermal consumers in a controlled or uncontrolled manner. The property is equipped with one or more generators of renewable, volatile electrical energy, with a connection to an external electrical energy supply network that allows both energy purchase and energy feed-in, as well as optionally additional consumers of electrical energy that are not connected through the control according to the invention can be controlled.

The energy consumed by the property or fed into the supply network can be measured. The current energy content of the storage can be determined through measurement, constant balancing or similar methods. The expected demand of the thermal consumers in a future that corresponds to the temporal storage capacity of the thermal storage can be calculated in advance if desired. The heating of the storage can be controlled in terms of performance and time, taking into account the expected time requirement and the currently available (if other consumers are present: excess) energy, so that the share of the energy coming from the energy generator in the total in a period of time in the thermal storage incoming energy is as high as possible.

According to the exemplary embodiment 2 is a single-family house with normal household consumers, electric storage heaters, some with fans, for living space heating, equipped with a photovoltaic system and a smart meter as a two-way meter to the utility company as well as a control system. The control includes: measuring the energy drawn and fed in via two S0 pulse outputs of the smart meter, measuring the storage core temperatures in the individual storage ovens as a measure of their energy content, measuring the outside temperature as a measure of the total energy requirement, programming the usage times of each one rooms. Optionally, an external weather forecast can be included for improved prediction of energy requirements as well as measurement of the room temperature(s) to estimate the uncontrolled release of thermal energy to the room.

When installing the parameterized connected load of the individual heating stoves, a calculation can be made that includes, for example, the expected energy requirements in the next 12 to 24 hours for the house or each room based on the outside temperature, if necessary the weather forecast and the times of use. Furthermore, the minimum or maximum permissible storage load per storage heater can be calculated from the energy requirement, the upper and lower comfort limits for the room temperature and the uncontrolled amounts of energy released into the room.

Furthermore, the energy consumption of individual storage heaters can be switched on or off if the individual minimum storage load is undershot, if the maximum storage load is exceeded, and/or if the current storage load lies between the two limits, to the extent that Excess energy is available from the local producer but is not needed by other consumers. For this purpose, the storage heaters can be switched on by the control system to the extent that the feed into the utility network is as close to zero as possible, but no energy is yet consumed. An example of a normal single-family house (built around the 1970s) has a connected load for the heating of around 10 to 20 kW and can accommodate a PV system of around 4-6 kW peak on the roof. The heating output is divided into small parts, e.g. in existing electric storage heaters, be it as individual heating stoves with a connected power of around 1 to 6 kW or in the case of underfloor storage heating through the individual heating circuits in the rooms. The control must know the performance of the individual heating elements in order to be able to calculate an optimal grouping.

Claims (10)

Method for heating rooms or buildings with at least partial use of renewable, volatile electrical energy from a generating system of such energy locally assigned to a room or building, this electrical energy being fed via a control system primarily into several electro-thermal storage units for heating the room or building and is fed subordinately into an external power grid, the electro-thermal storage if the thermal energy requirements of the electro-thermal storage or the room or building heated thereby are not sufficiently covered by the local generation system by electrical power fed externally into the room or building external power grid is supplied or co-supplied, an expected energy supply and an expected energy surplus of the local generation plant is determined, by programming parameters during installation, by taking into account a weather forecast, by taking into account past data, and by taking into account a rhythm of the energy requirements of consumers, and a The expected energy requirement of at least one room or building is determined by updating past requirements, learning cycles and/or, if the consumer is used for room heating, by analyzing the room temperature and its progression, analyzing the outside temperature and its progression, taking into account the User programmed usage times and/or taking into account a weather forecast, the electro-thermal storage at least a central storage, or a warm water or latent heat storage, and several decentralized storage, and in the event of an automatic outflow of heating energy from the electro-thermal storage into the room or building heated by it, at least the minimum and / or the maximum permissible storage temperature and / or the minimum and / or the maximum energy content of the storage, from the heat flow from the storage towards the room or building, the current heat requirement of the room or building and/or the permissible minimum and/or the maximum room or building temperature is calculated. Procedure according to Claim 1 , whereby the electro-thermal storage units are supplied with electrical energy by one or more electrical heating elements. Procedure according to Claim 1 or 2 , whereby other consumers of electrical energy in the room or building are preferably supplied with electrical energy from the locally assigned generation system before the electro-thermal storage. Procedure according to one of the Claims 1 until 3 , whereby at least one heating element operated with electrical energy is used to heat up the electro-thermal storage, the connected load of which is programmed as a parameter during commissioning. Procedure according to Claim 4 , whereby the connected load is automatically determined by measurements during commissioning and/or during operation. Procedure according to one of the Claims 1 until 5 , whereby the power drawn by the room or building from an external power grid and the power fed into the external power grid is measured. Procedure according to one of the Claims 1 until 6 , whereby the heating of the electro-thermal storage is controlled in terms of performance and/or time, taking into account the expected time requirement and the currently available energy, so that the proportion of the energy coming from the local generation plant in the total in a period of time in the electro-thermal Energy flowing into the storage is as high as possible. Procedure according to one of the Claims 1 until 7 , whereby heating elements operated with electrical energy are used to heat up the electro-thermal storage and, if there is a heat requirement, the heating elements are switched on at any time in such a grouping that their combined power consumption is as close as possible to the power generated by the generating system locally assigned to the room or building comes. Procedure according to Claim 8 , whereby when forming the grouping, the thermal energy present in the respective electro-thermal storage and/or the energy likely to be required in the future by the room or building supplied by the respective electro-thermal storage is/are taken into account. Procedure according to Claim 8 or 9 , whereby parameterization determines whether and/or to what extent the set heating output affects the line supply and. may exceed a power surplus.

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