PL219117B1 - Method for heating of residential buildings and heating system for a residential building - Google Patents

Abstract

Electrical energy, preferably photovoltaic energy stored in a buffer, is converted to heat in heat pump compressor (2), while the heating medium from the heat pump compressor is divided into two streams, of which one is directed to high heat capacity heaters, preferably to floor heaters, and the other is directed to small heat capacity and quick convection heaters, preferably with forced circulation of heated air. The individual blocks of the heating system work together by means of heat transfer ring (3), to which heat pump (2) and at least two heat outflows, preferably in the form of buffers, are connected. Heat buffer (20) is a low temperature supplier of the floor heating installation (21) while heat buffer (30) is the supplier of fan coil units (31). A ground or water heat exchanger (5) is connected to heat pump (2); heat pump (2) is powered with electrical energy, preferably from photovoltaic cell (1) by means of electrical energy buffer (7).

Description

Description of the invention

The subject of the invention is a method of heating residential buildings and a system heating system for a residential building.

A commonly known and frequently used method of space heating is used, in which the heat obtained in a boiler fired with gas, heating oil or solid fuel is transferred to finned or plate heaters located on the walls of the heated rooms, most often on the walls under the windows.

A method of space heating is also commonly known and often used, in which the heat obtained in a boiler fired with gas, fuel oil or solid fuel is transferred to underfloor heaters.

A commonly known and frequently used method of space heating is applied, in which electricity is supplied to the space to be heated and converted there into thermal energy in electric heating devices or resistance elements located in the floor.

There is also a known and frequently used method of heating rooms with the use of a heat pump, where the heat pumped from an external geothermal source is supplied to the coil flooded in the floor screed.

There is also a known and frequently used method of heating rooms using a heat pump, where the heat pumped from an external geothermal source is transferred to an air duct through which air flows from the heated rooms. In this duct, this air is heated by the central heat pump convector, after which this heated air is redistributed in the heated rooms.

There is also a known method of heating rooms, where the heat is generated in a heated renewable fuel - biomass, e.g. with straw briquettes or wood logs - boiler in the form of a fireplace with a water jacket, in which the generated heat is directed to the domestic hot water tank and to the circulation of central heating radiators.

The above-mentioned methods of heating rooms have specific advantages, but also specific disadvantages.

The problem of conflict arises when using fin, plate or similar radiators for space heating. The efficiency of fuel conversion in heating boilers into heat, especially in gas boilers, is the greater, the lower the boiler operating temperature. On the other hand, the heat efficiency of radiators is higher, the higher the temperature of the heating medium and the lower their heat capacity.

Currently, the most common option is a compromise between lowering the operating temperature of boilers and increasing the convection surface of heaters.

Distribution of heat to the rooms using the above-mentioned heaters allows for the reduction of energy consumption by temporarily lowering the temperature in defined periods, e.g. when the household members are at work. The thermal reaction of the heating system to lowering the temperature setting is felt in heated rooms, usually after several minutes. Nevertheless, the heating parameter maintained in the installation is definitely higher than for underfloor heating.

A frequently used method of increasing the efficiency of fuel consumption is to lower the temperature of the obtained heating medium and to use underfloor heating of the medium with a low temperature. However, the underfloor heater is characterized by a very high thermal inertia - the effect of changing the heating factor parameter is noticeable only after a few hours. Thus, the greater heating efficiency of the system is paid for by the inability to quickly regulate the temperature.

The main disadvantage of electric resistance heating, regardless of the further method of heat distribution in rooms, is its low gross efficiency, and often, especially in Poland, non-ecological nature - the consumption of electricity generated from conventional energy sources contributes to the greenhouse effect. Also, the very supply of electricity to the building is associated with large energy losses during its transmission. Burning the same amount of fuel in a modern local boiler used to produce this gross electricity would produce more heat than the heat obtained from that electricity directly converted to heat in resistance heaters. Although electric heaters with a low heat capacity are very well suited for

Due to the very high energy costs, they are rarely used.

The use of a central heat pump with an air outlet for heating apartment rooms, although it has the same advantage as radiator heating - a quick response - and is well suited for the application of targeted temperature reductions, has a major disadvantage: the air is mixed between rooms together with the air present in these rooms microflora, germs and bacteria. The solution proposed below, devoid of the above-mentioned disadvantage, consisting in the use of separate heat pumps for each heated room is very expensive to invest.

The use of a central heat pump to supply underfloor heating has all the disadvantages of underfloor heating described above.

The use of a heating boiler in the form of a fireplace with a water jacket has a basic disadvantage, which is the inability to adjust the instantaneous thermal power of the device. The fireplace requires careful manual dosing of fuel and is characterized by high combustion irregularity, and thus process instability, which results in momentary power surges, often resulting in the production of steam and heat discharge to the atmosphere, and the temperature regulation of the heaters is almost impossible - when the fireplace is on fire, the heating system becomes hot, often overheated.

The aim of the invention is to indicate a method that allows the maximum use of the efficiency of heat sources, ensuring their stable operation, while ensuring the full possibility of reducing energy losses by ensuring effective, fast, dynamic and selective temperature control of individual rooms.

The aim of the invention is also to indicate a technological system that allows the implementation of the indicated method.

The essence of the method of heating residential buildings, according to which photovoltaic energy is converted into heat in the heat pump compressor, to which geothermal heat is fed via a ground heat exchanger, is that geothermal heat, before being fed to the heat pump, is directed to overheated rooms , from which the recovered heat is directed to the heat pump, and then the heating medium discharged from the heat pump compressor is divided into two streams, one of which is directed to heaters with high heat capacity, preferably to underfloor heaters, and the other to low capacity heaters thermal and fast convection, preferably with forced circulation of the heated air, and the separation of the heating medium, carried out through flow dividers, preferably three-way valves, is carried out in proportion to the current demand, has the thermal power of individual heaters, and flowing at least one m from the streams, the heating medium is initially collected in the heat buffer, and then, through this buffer, it is directed to the heater, the excess heat, in order to fully use the heat pump compressor power, is stored in an additional heat buffer, while in the case of a smaller heat buffer, instantaneous heat demand, the efficiency of the heat pump compressor is reduced by changing the electrical parameters of this conversion energy, preferably the voltage and / or frequency, by means of an energy-electronic converter of the energy form.

It is advantageous if, by reducing the heat efficiency of the heat pump compressor, the efficiency of the pumps transporting the heating medium of photovoltaic origin and / or heating medium of geothermal origin to the receivers is reduced.

It is also advantageous if the streams directed to the underfloor heaters and / or convectors are mixed with the return streams from these devices, thus obtaining a stable temperature of the feed streams.

Moreover, it is preferable that the cold, prior to being discharged from the heat pump into the geothermal reservoir, is directed initially to the overheated compartment to cool it down.

The essence of the heating system according to the invention consists in the fact that a heat pump and at least two heat outlets are connected to the heat transfer ring, preferably in the form of buffers, the heat buffer of which is a low-temperature power supply for the underfloor heating system, and the heat buffer is a fan coil power supply and a heat buffer , which is a utility water tank, while a ground heat exchanger is connected to the heat pump, the heat pump is powered by electricity, preferably from a photovoltaic cell, via an electricity buffer, and a geothermal coolant is connected between the ground heat exchanger and the heat pump to which the fan coil block is connected.

PL 219 117 B1

It is advantageous if an ecological source of heat energy, preferably a fireplace with a water jacket, is connected to the heat buffer.

It is also advantageous if the heat buffers and the heat pumps are equipped with flow dividers which are arranged in the circulation of the ring or connected to it by an ejector.

It is also advantageous if a fireplace is connected to the ring via a flow divider or ejector.

Moreover, it is advantageous if a ground heat exchanger is additionally connected to the ring, either directly or via a heat exchanger.

The main effect of the application of the invention is a significant reduction or even complete resignation from conventional energy sources, by basing space heating on renewable ecological energy sources, and ensuring effective conditions for the conversion of energy carriers into heat and further transfer of this heat to the heated rooms while minimizing heat losses, with full automation of this process.

An important effect of the application of heat transfer technology between devices, known as the "heat ring", is high flexibility in heat transfer between heat sources, heat buffers and the heat receiving installation. A significant effect is the use of a cold geothermal source as a buffer to stabilize heat production in such an unstable device as a fireplace with a water jacket. The heat thrown there from the fireplace is re-transferred to the heating system during the active use of the heat pump.

An additional effect of the proposed method is the possibility of air-conditioning for heated rooms in the summer, without incurring additional costs. both investment and operational.

When solving the problem of the economic use of energy for heating a residential building, it was necessary to reconcile the following three basic, seemingly contradictory relationships, namely:

- the thermal efficiency of the heat source is higher, the lower the temperature of the heating medium - hence the most advantageous application of low-temperature heaters with a large surface,

- heat losses are lower, the lower the difference between the room temperature and the outside temperature - hence it is beneficial to keep the room temperature as low as possible and raise it only for the period of the presence of users and

- the heating efficiency of radiators is higher, the higher the temperature of the heating medium and the lower the heat capacity of the radiator.

Cost reduction was achieved thanks to the cascade of heating devices; a heat pump and a boiler fired with renewable fuels. Since the demand for the peak power of the heating system occurs in our climate only a dozen or so to twenty days a year - the use of a cascade heat pump-fireplace with a water jacket - allows you to purchase a heat pump with a lower power and, accordingly, purchase a solar battery system with a lower power. It also allows to reduce the buffer accumulating energy obtained from a photovoltaic battery by turning on a fireplace with a water jacket, operated by household members, to generate heat in winter afternoons and evenings. An additional effect is a specific warm atmosphere in the house with a flaming fireplace.

The flexibility of controlling the heat transfer between heat sources and receivers and intermediate heat buffers was achieved thanks to the introduction of heat transfer between these devices with the use of a circulation "circular circulation of a thermodynamic medium, hereinafter referred to as a" heat ring ".

The invention will be explained on the basis of exemplary embodiments shown in the drawing, in which the individual figures Fig. 1, Fig. 2, Fig. 3 and Fig. 4 show four different heating installations in block form.

P r z k ł a d 1

The heat pump 2 is supplied with geothermal heat from a cold source of geothermal energy via a ground exchanger 5, and electricity from a photovoltaic cell 1 via an electricity buffer 7, in which the parameters of this energy are collected and converted according to the demand of the compressor of the heat pump 2 .

The heat generated in the heat pump compressor 2 is distributed between the three heat buffers 10, 20 and 30 via a heat ring 3 equipped with flow dividers 4, for example by three-way valves that can redirect the flow of a thermodynamic medium (heat carrier) flowing in the ring. ) to each of the buffers.

The heat buffer 20 further supplies heat to the low-temperature floor heating system 21 of the building's rooms. Successively to the heat consumption by the underfloor heating system, the thermodynamic medium in the heat buffer 21 of this installation is heated within the limits from T1 _mj n (then the heat flux is switched from the ring to the buffer 20) - to T1 _max - (then the heat flux is disconnected from the ring to buffer 20). Due to the high thermal inertia of the underfloor heating system 21, the average temperature of the buffer 20 is weather-adjusted and kept constant at such a level as to obtain the room temperature in the heated rooms, determined during the absence of users, e.g. at 17 ° C.

The heat buffer 30 supplies heat to the installation of fan coil units 31 for rapid heating of individual rooms in the building. Successively to heat consumption by the installation of fan coil units 31, the thermodynamic medium in the heat buffer 30 is heated in the range from T2 _mn (switching the heat flux from the ring to the buffer 31), to T2 _max (switching off the heat supply to this outflow / buffer from the ring by shifting the distributor stream 4 of this buffer 30 for the circulation of the ring). Due to the low heat capacity of the fan coil installation 31, in the absence of users, the average temperature in this installation is kept at a low level, e.g. the same as in the heat buffer 20 of the underfloor heating installation 21. However, when the users return home, this temperature is increased. , e.g. by 15 ° C, to ensure a quick response to a change in the temperature setpoint for a specific room from the standby temperature to the thermal comfort temperature, determined by the user setting. As soon as the user / s moves to another room, the fan coil in the abandoned room is turned off and the fan coil in the room just used is turned on.

Thanks to the separation of two separate heating systems: the underfloor heating system (heat buffer 20 and underfloor heating system 21), supplying the rooms with most of the heat at a very low operating temperature, and the fan coil system characterized by low thermal inertia (heat buffer 30 and fan coil installation 31), for which supplies a small part of the heat demanded by the rooms with a thermodynamic medium with a slightly higher temperature - the effect of heating the rooms with ensuring thermal comfort, mainly by supplying low-temperature heat, because the amount of heat supplied by the fan coil installation 31, fed with medium-temperature heat, is proportionately small. The rooms selected in space and time are heated only by a few degrees K, e.g. from T = 17 ° C maintained by underfloor heating to T = 22 ° C, i.e. only by Delta T = 5 ° K, while, for example, an outside temperature of -10 ° C, the underfloor heating system 21 provides low-temperature space heating with a temperature difference of Delta T = 27 ° K.

The heat buffer 10 is a domestic hot water tank. Due to the daily cyclical availability of the sun's radiant energy, it is intensively heated during the day. It also performs another important function in the autumn / spring period, when the heat dissipation for space heating is smaller than in the winter peak. Since the heat pump 2 has the disadvantage of frequently switching it on and off, in this period of low heat demand for space heating, the heat buffer 20 of the underfloor heating system 21 or the heat buffer 30 of the fan coil system 31 is heated up in short intervals. In order not to have to switch the heat pump 2 on and off in such conditions, after heating the buffer, the valves of the flow dividers 4 of the heat ring 3 cut off this buffer from the heat ring 3 and turn on the buffer 10 of the domestic hot water tank, which is further heated by the heat pump 2 without turning it off. The heat pump 2 is turned off only after heating the hot water tank 10 of the domestic hot water tank, which is characterized by high heat capacity, practically only after a several-minute cycle of operation. Then, when there is a need to reheat the buffer 20 of the underfloor heating system 21, the heat is first transferred to the buffer 20 from the buffer 10 of the domestic hot water tank, by simultaneously opening the flow divider valve 3 of the buffer 10 of the domestic hot water tank and the valve of the flow divider 4 to the heat ring 3. buffer. Heat pump 2 is not running during this time. The pump is turned on only when, due to the dissipation of heat for heating, both the temperature of the buffer 20 or 30 and the buffer 10 of the domestic hot water tank drops. When switched on, the heat pump 2 first charges the buffers 20 and / or 30 of the heating system with heat and only then, without interrupting its operation, recharges the heat into the buffer 10 of the domestic hot water tank. Thanks to this way of using the ability of the ring 3 to flip6

After heat transfer between the buffers connected to it (10, 20 and 30), the number of on / off heat pump 2 is minimized.

In summer, the fan coil units 32 cooling the room are switched over with the switch 11 three-way valves to the supply of coolness obtained from a cold geothermal source via a heat exchanger 5. In the exemplary solution, this is done by sucking the medium (cold water) from the stream of the thermodynamic medium supplied from the heat exchanger 5, circulating in the primary circuit of the heat pump 2. The heat, captured by the fan coil units 32 from the rooms to be cooled, heats this thermodynamic medium, which, when heated, is then reintroduced into the primary circuit before the heat pump 2. Thus, the heat from the rooms to be cooled is recovered by the fan coil units 32 it is transferred to the heat pump 2 and is then conveyed by this pump via the heat ring 3, e.g. to the buffer 10 of the domestic hot water tank or directly to the buffer 30 supplying heat to the installation of fan coil units 31 heating the rooms, e.g. on the north side of the building.

During the period when the heat pump 2 does not heat the buffer 10 of the domestic hot water tank, the heat captured from the air-conditioned rooms is transported through the ground exchanger to the cold geothermal source 5 to gradually increase the temperature of the heat exchanger 5 throughout the summer, accumulating for use in the winter period. . Paradoxically, the more cooling we provide to cool air-conditioned rooms in summer, the longer the heat pump works in winter with better parameters - the lower source is warmer.

P r z k ł a d 2

The arrangement is analogous to example 1, except that the buffer 10 of the domestic hot water tank is additionally heated with heat obtained from a source of ecological thermal energy, preferably in a fireplace with a water jacket, further in the examples referred to as fireplace 8, and the heat ring 3 is via a switch 9 connected via drain 6 to geothermal heat exchanger 5 via primary return of heat pump 2.

The installation works similarly, except that when the fireplace 8 starts working, the heat pump 2 is turned off and - to protect against high temperature of the heat transferred in the ring 3 - disconnected from the ring by shifting the three-way valve of the flow divider 4 servicing heat pump 2, and all heat obtained from the fireplace is transferred by means of ring 3 into buffers 20 and / or 30 and collected first in these buffers and then collected in buffer 10 of the domestic hot water tank.

After the operation of the fireplace 8 is finished, in the first period when the DHW tank buffer 10 has accumulated excess heat, the heating of the heat buffer 20 of the underfloor heating system 21 and / or the buffer 30 of air conditioning units 31 is carried out by transferring the heat from the DHW tank buffer 10 to these buffers, described in detail in example No. 1.

Due to the possibility of temporary occurrence of a temperature in the buffer 10 of the domestic hot water tank much higher than the standard temperature for domestic hot water, it is advantageous to use a valve at the outlet of the domestic water tank that mixes hot water from the domestic hot water tank with cold water in order to provide utility water with the desired parameters, in particular maintaining this temperature. temperature thanks to the thermostatic control of this mixing valve.

In the case of excess heat temporarily obtained from the fireplace 8, this heat is transferred to the ground heat exchanger 5 by directing this heat through the outlet 6 to the return circuit of this exchanger and thus to a cold source of geothermal energy, due to the displacement of the switch 9. Thus, the excess heat obtained in a fireplace 8 fired with renewable fuel (wood chips) is buffered in the ground so as not to be thrown out with the generated steam into the atmosphere through the fireplace's safety valve, as is usually the case in this type of fireplace installations with a water jacket.

In summer, the cold from the ground heat exchanger circuit of a cold geothermal source can be directed through the outlet 6, switch 9 and ring 3 to the buffer 30 of the fan coil installation 31. Thanks to this solution, it is not necessary to use fan coil units 31 or cooling fan coil units 32 in the installation circuit. separate switches or heat exchangers, as was the case in example No. 1. However, in this solution it should be remembered that while charging the heat generated by the heat pump 2 and transferred further to the buffer 10 of the domestic hot water tank through the ring 3, the transfer is temporarily prevented cooling to the buffer 30 of fan coil installations 31. This collision was solved in an exemplary application by coordinating both actions, both with the daily cycle of solar electricity availability, the cycle of additional external temperature variability (usually there is no need to cool the rooms in the morning when the outside temperature is outdoor is the lowest, and the available photovoltaic energy can be used to heat domestic hot water) and the daily schedule of the installation users.

P r z k ł a d 3

The installation according to example 3 works as in the previous examples, except that the fireplace 8 is directly connected to the ring. It is possible to use either a flow switch (three-way adjustable valve) or the injection of a thermodynamic medium from the fireplace circuit 8 to the ring circuit. The hot thermodynamic medium obtained in the fireplace 8 is then injected by the pump serving the fireplace into the heat ring 3 and there it is carried away by the flow circulating around the ring (circulation of the heating medium in the ring is forced by the circulating pump in the ring). For the duration of the fireplace 8 operation, the heat pump 2 is switched off from work for ring 3, due to its protection against overheating by the high operating temperature parameter of the ring in this operating option. In the first stage of the fireplace operation 8, buffers 20 and 30 for space heating are heated, then the buffer 10 of the domestic hot water tank is heated to the maximum temperature. If, after achieving this goal, the fireplace 8 continues to operate and supplies heat to the ring 3, this heat is dissipated to the ground heat exchanger 5 via the drain 6, through the controlled opening of the flow switch 9 (e.g. in the form of a three-way valve connecting the geothermal source circuit with the ring). heat 2), while both due to the safety of the fireplace 8 and to maximize the efficiency of heat extraction by the fireplace 8, the temperature in the ring 3 and in the fireplace circuit is kept as low as possible, but sufficient for the ongoing operation of buffers 20 and 30 space heating, according to the actual heat consumption by an underfloor heating system 21 and a fan coil system 21.

The properties of the installation described in example 3 are analogous to the properties of the installation in example 2. The advantage of this solution is the greater efficiency of accumulating the heat obtained from renewable fuel in the fireplace 8 in the geothermal energy source, as well as better use of the internal heat exchanger surface of the buffer 10 of the domestic hot water tank, which is particularly important in the operating mode of ring 3 with heat pump 2. This solution also offers favorable options for selecting the buffer 10 type due to the availability of domestic hot water tanks on the market.

By using in any known manner an additional heat exchanger between the sections of the internal heat exchanger of the heat buffer 10, e.g. a four-way valve, it is possible to combine the arrangement shown in Fig. 2 with the arrangement shown in Fig. 3. Such a combined solution allows a much more efficient use of the surface area. internal heat exchanger coils of the buffer 10 of the domestic hot water tank in operation with the heat pump 2, structurally provided in the solution according to Fig. 3, while maintaining the advantages of the arrangement according to Fig. 2.

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The latter example shows another embodiment of the application of the invention, in which the installation works analogously to example 3, but the fireplace 8 is connected to ring 3 via a switch 4. A stable temperature in the ring is maintained by mixing with cold drawn from a cold geothermal source, using a heat exchanger 61 installed in the drain 6. The excess heat generated in the fireplace 8 is discharged to the geothermal source through the drain 6 and the exchanger 61. In summer, the cold to the rooms is taken directly from the ground heat exchanger 5 and further directed to the room cooling system (e.g. air conditioning). convectors 32) through the flow switch 11 installed in the circuit supplying the heat pump 2 with geothermal cooling.

Claims (9)

Patent claims A method of heating residential buildings, according to which the electric energy stored in the buffer, preferably photovoltaic energy, is converted into heat in a heat pump compressor, to which geothermal heat is fed via a ground heat exchanger, characterized in that geothermal heat, before being fed to the the heat pump is directed to overheated rooms, from which the recovered heat is directed to the heat pump, and then the heating medium discharged from the heat pump compressor is divided into two streams, one of which is directed to heaters with high heat capacity, preferably to floor heaters while the other is for heaters with low heat capacity and fast convection, preferably forced Due to the current heat demand of the individual heaters, the heating medium is separated by flow dividers, preferably three-way valves, in proportion to the current demand, and the heating medium flowing in at least one of the streams accumulates initially in the heat buffer, and then, through this buffer, it is directed to the heater, the excess heat, in order to fully use the power of the heat pump compressor, is stored in an additional heat buffer, while in the case of lower instantaneous heat demand, it is reduced, by means of an energy-electronic converter of the energy form, the efficiency of the heat pump compressor by changing the electrical parameters of this conversion energy, preferably voltage and / or frequency. 2. The method according to p. A method according to claim 1, characterized in that by reducing the thermal efficiency of the heat pump compressor, the efficiency of the pumps transporting the heating medium of photovoltaic origin and / or heating medium of geothermal origin to the receivers is reduced. 3. The method according to p. A process as claimed in claim 1, characterized in that the streams directed to the floor heaters and / or convectors are mixed with the return streams from these devices, thus obtaining a stable temperature of the feed streams. 4. The method according to p. A method as claimed in claim 1, characterized in that the cold, before being discharged from the heat pump into the geothermal reservoir, is initially directed to the overheated compartment in order to cool it. 5. System heating system of a residential building in which the heating process is carried out by means of a heat pump, characterized in that a heat pump (2), at least two heat outlets, preferably in the form of buffers (20), are connected to the heat transfer ring (3). and 30), of which the heat buffer (20) is a low-temperature power supply for the underfloor heating system (21), and the heat buffer (30) is a power supply for fan coil units (31) and the heat buffer (10), which is a utility water tank, while for the heat pump ( 2) a ground heat exchanger (5) is connected, the heat pump (2) being supplied with electricity via the electricity buffer (7), preferably from a photovoltaic cell (1), and between the ground heat exchanger (5) and the heat pump (2) is connected to the geothermal chill switch (11) to which the fan coil block (32) is connected. System arrangement according to claim 1. 5. A method as claimed in claim 5, characterized in that an ecological source of heat energy, preferably a fireplace (8) with a water jacket, is connected to the heat buffer (10). System arrangement according to claim 1. 5 or 6, characterized in that the heat buffers (10), (20) and (30) and the heat pumps (2) are equipped with flow dividers (4), which are located in the circulation ring (3) or are connected by ejectors . System arrangement according to claim 1. 5, 6 or 7, characterized in that a fireplace (8) is connected to the ring (3) via a flow divider (4) or by an ejector. System arrangement according to one of Claims 5 to 8, characterized in that a ground heat exchanger (5) is additionally connected to the ring (3), either directly or via a heat exchanger (61).