LV15618B - A system for indoor microclimate control and a method for control thereof - Google Patents

Abstract

The invention relates to the field of heating technology, more specifically to the indoor microclimate maintenance systems of buildings. The system of the invention utilizes wastewater energy for indoor heating, hot water and free cooling and includes control techniques for such systems.

Description

DESCRIPTION OF THE INVENTION

Technical sector

[001] The invention relates to indoor microclimate maintenance systems, for providing heating, hot water supply and subcooling using wastewater potential, and to control techniques for such indoor microclimate maintenance systems.

Analysis of the prior art

[002] Various heating and cooling systems for buildings are known, where in most cases the heating and cooling functions are provided by unrelated systems. Thus, their operation and management is complex and not always coordinated. There are also attempts to create systems that combine heating and cooling functions, but they are also complicated and do not always ensure the installed energy efficiency. Accordingly, the aim of the invention is to create an efficient and easy-to-use heating and cooling system.

[003] The purpose of the invention is achieved by creating an indoor microclimate maintenance system that contains a waste water accumulation tank in synergy with heating and cooling systems. The system contains a wastewater solids separation tank for the separation of the thick fractions of wastewater, connected to the wastewater accumulation tank. In addition, the system contains a waste water inlet connected to the waste water solids separation tank in such a way that the inflowing waste water can pass through the waste water solids separation tank into the waste water accumulation tank. On the other hand, the circuit of the heating heat exchanger and the circuit of the subcooling heat exchanger are placed in the waste water accumulation tank. The cooling heat exchanger circuit is located below the heating heat exchanger circuit.

Outline of the invention

[004] To provide control of the system, the system includes an influent control valve connected to the effluent inlet and configured to control the influent effluent. The heating heat exchanger circuits have a first heating heat exchanger circuit flow valve configured to change the heating surface area of the heating heat exchanger circuit. The heating heat exchanger circuits may additionally have a second heating heat exchanger circuit flow valve configured to additionally change the heating surface area of the heating heat exchanger circuit. The system further comprises a subcooling heat exchanger circuit flow valve connected to the subcooling heat exchanger circuit and configured to vary the cooling surface area of the subcooling heat exchanger circuit. Also, the system contains several sensors. An influent thermometer located in the effluent inlet or in the effluent solids separation tank and configured to measure the temperature of the influent effluent. A heating heat exchanger circuit thermometer located near the heating heat exchanger circuit and configured to determine the temperature in the heating heat exchanger circuit area. A subcooling heat exchanger circuit thermometer located near the subcooling heat exchanger circuit and configured to measure the temperature in the subcooling heat exchanger circuit area. An inflow meter connected to the wastewater inlet and configured to measure the amount of inflowing wastewater. A heating heat exchanger circuit heat meter connected to the heating heat exchanger circuit and configured for accounting of instantaneous heat demand. A subcooling heat exchanger circuit heat meter connected to the subcooling heat exchanger circuit and configured to count the instantaneous demand for cooling.

[005] In addition, the system contains a control unit connected to the above-mentioned thermometers for receiving temperature reading data from the relevant nodes of the system and with the inflowing wastewater meter for receiving the inflowing wastewater volume reading data, and with the above-mentioned meters for receiving data on the instantaneous heat demand. Also, the control unit is connected to the valves for their control based on the data received from the mentioned thermometers and counters.

[006] The indoor microclimate maintenance system additionally comprises a sewage pump well placed between the sewage supply and the sewage inlet for supplying sewage to the sewage inlet.

[007] In addition, the indoor microclimate maintenance system additionally comprises a thick fraction pressure line, which at the end, located in the waste water solids separation tank, contains a pump configured to convey the separated thick fraction to the waste water collection system.

[008] The system additionally contains a pressure cooling tank connected to a waste water accumulation tank and a waste water solids separation tank for receiving the thick fraction separated therein, thus ensuring a decrease in the pressure of the waste water.

[009] In addition, a new management technique for the indoor microclimate maintenance system was developed. The management technique includes the following steps:

a) receiving the instantaneous cooling demand value (QFREE) in Joules (J) in the control unit from the heat meter of the cooling heat exchanger circuit and/or receiving the instantaneous heat demand value (QHEAT) in Joules (J) in the control unit from the heating heat exchanger circuit;

b) opening the inflow control valve if the instantaneous cooling demand value (QFREE) is less than the instantaneous heat demand value (QHEAT) and closing the inflow control valve if the instantaneous cooling demand value (QFREE) is equal to or greater than the instantaneous heat demand value (QHEAT);

c) setting the highest temperature threshold (TH16) and the lowest temperature threshold (TL16) for the temperature values coming from the circuit thermometer of the free-cooling heat exchanger,

d) setting the heating mode; or

e) setting the cooling mode.

[010] In the control unit, the lowest and highest wastewater temperature must be set before returning to the city wastewater networks (hereinafter referred to as the discharge temperature), this temperature will be displayed by the circuit thermometer of the free-cooling heat exchanger. These temperatures serve as a criterion for determining the state of the system and determine the operating temperature corridor of the equipment, it is the lowest discharge temperature in winter, below which the system must not cool the wastewater, and the highest discharge temperature in summer, above which the system must not raise the temperature of the wastewater before discharge. In moderate climatic conditions, to ensure heating needs in the winter period and indoor cooling needs in the summer period, the optimal temperature distribution corridor is 7°C - 18°C. When operating in heating mode, this temperature will limit the heat recovery potential, the lower the set temperature, the higher the heat recovery potential and vice versa.

[011] Furthermore, the highest temperature threshold (TH16) is the highest temperature in summer above which the system must not increase the temperature of the wastewater in the sewage storage tank, and furthermore the lowest temperature threshold (TL16) is the lowest temperature in winter below which the system must not reduce the temperature of the wastewater in the sewage storage tank. In order to ensure favorable, comfortable conditions for the residents of the building, the highest temperature threshold (TH16) should be set at 18°C (29IK) and the lowest temperature threshold (TL16) should be set at 7°C (280K).

[012] The control unit, upon receiving the data, calculates the total heat balance, knowing the instantaneous heat demand from the heating heat exchanger circuit heat meter and the free cooling heat exchanger circuit heat meter. Before reporting to the control unit about the opening of the waste water inlet valve, the current state of the system must be determined by determining what is the heat potential generated by the free-cooling mode, which is detected by the heat meter of the free-cooling heat exchanger circuit. If the value of the heat counter of the free-cooling heat exchanger circuit - the value of the heat counter of the heating heat exchanger circuit < 0, then the control unit performs the calculation according to equation (40) and instructs the command to open the sewage inlet valve, supplying the sewage flow from the city to the value of the heat counter of the free-cooling heat exchanger circuit - heating heat exchanger circuit heat meter value + inflowing wastewater meter value >= 0 and the system balance state is reached to compensate for the lack of heat in the system. The data from the measuring devices to the control unit is preferably updated 1 time per minute, every time data is received from the devices. However, if necessary, the data recovery time can be shortened or extended. The control unit fixes the state of the system, thereby determining the direction of the heat flow, for example, a possible situation where the wastewater in the tank approaches the discharge temperature, however, after fixing the system state, it turns out that the increase in heat flow from the free-cooling mode is greater than what is required for heating purposes, then the control unit do not command the sewage inlet valve to open yet, because the heat increase in the tank is expected and the heat potential of the city sewage is not needed.

[013] Setting the heating mode involves determining the instantaneous heat demand value (QHEAT) in the control unit according to the following equation:

QHEAT = QFREE + ((T14 - T16) * c * M) [J], (40) where

QFREE is the instantaneous cooling demand value (QFREE) [J],

M - volume of wastewater inflow [kg/s], counted by the inflowing wastewater meter, c - heat capacity [J/kg*K],

T16 - temperature value [K] recorded by the circuit thermometer of the free-cooling heat exchanger, and

T14 - temperature value [K] recorded by the inflowing wastewater thermometer.

In addition, in the heating mode, if the temperature value (T16) approaches the lowest temperature threshold (TL16), then the control unit determines the QHEAT value according to equation (40), and if the determined QHEAT value is not equal to QFREE, the control unit sends a signal to the inflow control valve for its opening, and the influent control valve is closed after QHEAT equals QFREE after recalculation.

[014] Accordingly, if during the heating period the value on the free-cooling heat exchanger circuit thermometer approaches the lower set temperature, the control unit calculates according to equation (40) and if the QHEAT value is not equal to QFREE, then a command is sent to the control unit to open the waste water inlet valve and supply for the system urban wastewater from the network with a higher heat potential until the conditions of equation (40) are fulfilled. At the moment when the wastewater potential in the tank increases and the heat demand in the building decreases, the control unit reads it from the values of the flow and temperature graphs of the heating heat exchanger circuit heat meter, sequentially, sending a command to the wastewater inlet valve to close it, because the system is in balance.

[015] ] On the other hand, setting the cooling mode involves determining the instantaneous cooling demand value (QFREE) in the control unit according to the following equation:

QFREE = QHEAT + ((T16 - T14) * c * M) [J], (50) where

QHEAT is the instantaneous heat demand value (QHEAT) [J],

M - volume of wastewater inflow [kg/s], counted by the inflowing wastewater meter, c - heat capacity [J/kg*K],

T16 - temperature value [K] recorded by the circuit thermometer of the free-cooling heat exchanger, and

T14 - temperature value [K] recorded by the inflowing wastewater thermometer.

[016] In addition, in the cooling mode, if the temperature value (T16) approaches the highest temperature threshold (TH16) and the instantaneous cooling demand value (QFREE) is greater than the instantaneous heat demand value (QHEAT), then the control unit determines the QFREE value according to equation (50) , to open the inflow control valve and close it after the condition of Equation (50) is satisfied.

[017] The upper wastewater temperature is set in the system control unit before the wastewater is discharged from the tank, respectively, if the free cooling mode heats the wastewater to the upper temperature. As the wastewater approaches the upper temperature in the tank, the control unit analyzes the data from the circuit thermometers. Accordingly, under the condition when a temperature increase is observed in the tank at the free cooling circuit at the upper distribution temperature limits, the system state is fixed and under the condition when the heat counter value of the free cooling heat exchanger circuit - heat counter value of the heating heat exchanger circuit > 0, then the control unit executes the equation (50 ) calculation and gives the task to open the waste water valve, supplying the city waste water in the calculated volume, until the waste water temperature in the tank is properly reduced and the condition is fulfilled: the value of the heat meter of the circuit of the free cooling heat exchanger - the value of the heat meter of the circuit of the heating heat exchanger - the value of the meter of the inflowing sewage =< 0, reaching the balance of the system pregnant.

[018] During the summer period, the upper limit of the setting works, providing a suitable free-cooling mode for indoor cooling, the control unit reads the value on the free-cooling heat exchanger circuit thermometer, if it approaches the upper temperature limit, then a command is sent to the control unit to open the sewage waste water valve and supply the system with city waste water from the network with a lower heat potential until the conditions in equation (50) are satisfied. At the moment when the wastewater potential in the tank decreases and the indoor cooling demand in the building decreases, the control unit reads it from the values of the flow and temperature graphs of the heat meter of the free-cooling heat exchanger circuit, sequentially, sending a command to close the sewage wastewater valve, since the system is in balance.

[019] The object of the invention can be used in the energy supply of the building, it is possible to provide heating, hot water and indoor cooling of the building in the so-called free cooling mode. The device is particularly effective for installation in the city's centralized sewage networks, because here the volume and temperature of the sewage is constant throughout the year. The volume of wastewater is higher in the winter months, but the temperature decreases (8-10°C), the volume of wastewater decreases slightly in the summer months, but its temperature increases (14-16°C). The device is designed to use city wastewater only in the amount necessary to ensure the installed heating and cooling parameters. This means that in cases where the building's heat demand coincides with the indoor cooling demand, wastewater from the city network is not used at all.

[020] During the summer months, with a higher indoor cooling demand, the waste water in the tank heats up, if there is a constant heat demand in the building, for example hot water, then the heat pump will turn on, which will cool the waste water in the tank, through the heat pump circuit for heating purposes, depending on the heat demand in the building, thus free cooling mode will not require city waste water to maintain the set indoor cooling mode. At the moment when the temperature of the tank increases, because the tank will not cool down enough for heating purposes through the heat pump circuit, the sewage pump will turn on and deliver sewage from the city sewage network, with a lower temperature, ensuring the indoor cooling demand. In this case, the wastewater will be returned to the city network at a higher temperature, which does not interfere with its treatment at the wastewater treatment plant. On the other hand, in the cooling mode, an option is possible when peak loads are cooled by compressor equipment.

[021] In the winter months, in buildings with 0 energy consumption, there is a regular demand for indoor cooling (the same is true in production rooms, server rooms, etc.), southern facades heat up, northern ones cool down. This means that when heat is removed from the room, it is led to the waste water tank through the free cooling circuit, where the said heat is used by the heat pump circuit for heating purposes. That is why the device does not completely depend on the city's sewage networks when producing heat, they cover the difference that is not provided by the free cooling mode, minimizing the potential of heat removed from the city's sewage, even increasing it in some cases. This, in turn, does not increase the load on wastewater treatment plants and creates cheap, energy-efficient and green energy.

[022] The control unit regulates the flow control valves based on the instantaneous heat demand and the heat potential in the waste water storage tank. The heat potential in the tank is measured depending on the wastewater inflow and temperature. The circuits of the sewage heat exchanger are separated by flow valves to reduce hydraulic resistances. The first circuit of the heating heat exchanger is located in the upper part of the tank and is always open, the following circuits are opened as needed to increase the capacity of the waste water heat exchanger depending on the demand of the heat pump. It is identical with the free cooling circuit. The contours are placed according to the direction of the heat gradient in the tank, the lowest temperature in the lower part, the higher temperature in the upper part. Tanks are calculated with a margin to ensure smoother heat exchange, as well as to reduce the impact of possible network emergency risks on system operation. The system control unit takes into account the wastewater outlet temperature, not allowing it to decrease below the set temperature. The system is set to the potential for changes in the wastewater temperature, the difference of which is measured at the entrance to the sewage solids separation tank and at the exit to the city networks. This difference can be changed depending on the temperature of the wastewater and the required heat potential of the wastewater during the seasons. The lower the difference, the more often the volume of wastewater in the tank should be changed. This allows the system to balance and reduce the impact of winter and summer peak loads.

[023] In the free-cooling mode, the control unit controls the flow valve of the free-cooling heat exchanger circuit identically. If the set temperature difference is not provided, then the flow valve of the circuit of the free-cooling heat exchanger is opened, thus increasing the flow and the heat transfer area in the waste water tank. In the control unit, the opening/closing of the circuit flow valve of the free-cooling heat exchanger is set to changes in the flow rates, these values can be changed in the system.

[024] The essence of the invention is explained in more detail by the examples of its realization in the following drawings.

[025] Fig. 1 is the basic scheme of the indoor microclimate maintenance system.

[026] Fig. 2 is the basic diagram of the indoor microclimate maintenance system, supplemented with an illustration of the control unit (20) and related elements.

[027] Fig. 3 is a graph showing the potential of wastewater networks in kWh at the amount of wastewater available at the given stage depending on the set wastewater cooling limit (t° - IK).

[028] Figures 1 and 2 one embodiment of the invention is illustrated. An indoor microclimate maintenance system comprising a waste water accumulation tank (1), a waste water solids separation tank (2) for separating the thick fractions of waste water, connected to said waste water accumulation tank (1). The waste water solids separation tank (2) is connected to the waste water inlet (3) in such a way that the inflowing waste water through the waste water solids separation tank (2) can enter the waste water accumulation tank (1). In addition, the waste water inlet (3) contains an inflow waste water inlet valve (10) configured to control the inflow waste water. Additionally, an influent thermometer (14) is located at the effluent inlet (3) configured to measure the temperature of the influent effluent (see Fig. 1). On the other hand, Fig. 2 shows a variant of the implementation of the invention, when the wastewater thermometer (14) can be placed in the wastewater solid particles separation tank (2). A sewage pump well (30) is located before the sewage inlet (3), which in turn is connected to the sewage supply (31). On the other hand, the circuit of the heating heat exchanger (7) with the heating inlet (4) and the circuit of the free-cooling heat exchanger (9) with the free-cooling inlet (5) are placed in the waste water accumulation tank (1). In addition, the circuit of the free-cooling heat exchanger (9) is located below the circuit of the heating heat exchanger (7), closer to the base of the tank (1). The heating heat exchanger circuit (7) is connected to the first heating heat exchanger circuit flow valve (11) configured to change the heating surface area of the heating heat exchanger circuit (7). In addition, the heating heat exchanger circuit (7) is connected to the second heating heat exchanger circuit flow valve (12), which is configured to additionally change the heating surface area of the heating heat exchanger circuit (7). In turn, the free-cooling heat exchanger circuit (9) is a free-cooling heat exchanger circuit flow valve (13), which is configured to change the cooling surface area of the free-cooling heat exchanger circuit (9).

[029] In addition, the system contains sensor elements for obtaining data necessary for system control. The system contains a heating heat exchanger circuit thermometer (15) located near the heating heat exchanger circuit (7) and configured to determine the temperature in the heating heat exchanger circuit (7) area, and a free cooling heat exchanger circuit thermometer (16) located in the free cooling heat exchanger circuit (9) nearby and configured to determine the temperature in the zone (9) of the free-cooling heat exchanger. The system further comprises an inflow meter (17) connected to the wastewater inlet (3) and configured to count the amount of inflowing wastewater. Also, the system contains the heat meter of the heating heat exchanger circuit (18), which is connected to the heating heat exchanger circuit (7) and is configured for accounting of the instantaneous heat demand, and the heat meter of the free cooling heat exchanger circuit (19), which is connected to the free cooling heat exchanger circuit (9) and configured for cooling for instant demand accounting. To provide system control, the system includes a control unit (20) configured to control the system. The control unit (20) is connected to thermometers (13, 14, 15) for receiving temperature reading data and to the incoming wastewater meter (17) for receiving incoming wastewater volume reading data, and to meters (18; 19) for receiving data on instantaneous heat demand, and with valves (5; 10; 11; 12; 13) for their control based on data received from thermometers (13, 14, 15) and counters (17; 18; 19). See fig. 1 and 2.

[030] The indoor microclimate maintenance system additionally contains a thick fraction pressure line (32), which at the end, located in the waste water solids separation tank (2), contains a pump (35) configured for conveying the separated thick fraction to the waste water collection system (33). The system additionally comprises a pressure cooling tank (34) connected to a waste water accumulation tank (1) and a waste water solids separation tank (2) for receiving the thick fraction separated therein, thereby providing a reduction in waste water pressure. See 1. and

Fig. 2

Fig. 3 the potential of the wastewater network in kWh is shown, where a 1.5°C (274.5K) difference between the temperature of the incoming and outgoing wastewater is set in the system. As can be seen in the example, the heating demand is partially covered by the heat generated by Frecooling in the tank. 530 m ³ /day is available in the specific section of the sewage supply network, in this scenario only 44 m ³ of sewage is needed per day to ensure the operation of the system.

[0 31] While the invention may be susceptible to various modifications and alternative forms, specific solutions of which are exemplified in the drawings and described in detail herein, it is to be understood that the invention is not intended to be limited to the forms specifically disclosed herein. Rather, the invention includes all modifications, equivalents, and alternatives that fall within the scope of the invention as defined in the following claims.

1032] List of references

- waste water accumulation tank;

- waste water solid particles separation tank;

- wastewater inflow;

- heating introduction;

- introduction of free cooling;

- heating heat exchanger circuit;

- circuit of the free cooling heat exchanger;

- inlet valve for inflowing wastewater;

- the first circuit flow valve of the heating heat exchanger;

- the second circuit flow valve of the heating heat exchanger;

- free cooling heat exchanger circuit flow valve;

- inflowing wastewater thermometer;

- heating heat exchanger circuit thermometer;

- free-cooling heat exchanger circuit thermometer;

- incoming wastewater meter;

- heat meter of the circuit of the heating heat exchanger;

- heat meter of the circuit of the free-cooling heat exchanger;

- control unit;

- sewage pump well;

- sewage supply;

- thick fraction pressure pipe;

- pressurized cooling tank;

- pump;

- equation for determining the instantaneous heat demand value;

- equation for determining the instantaneous cooling demand value;

QFREE - instantaneous cooling demand value [J];

QHEAT - instantaneous heat demand value [J],

M - volume of wastewater inflow [kg/s];

c - heat capacity [J/kg*K];

T16 - temperature value [K] recorded by the circuit thermometer of the free-cooling heat exchanger;

T14 - temperature value [K] recorded by the inflowing wastewater thermometer;

TL16 - the lowest temperature threshold; and

TH16 - the highest temperature threshold.

Claims (7)

1. Indoor microclimate maintenance system, which contains: waste water accumulation tank (1), waste water solids separation tank (2) for the separation of waste water thick fractions connected to the waste water accumulation tank (1), waste water inlet (3) connected to the waste water solids separation tank (2) in such a way, that the inflowing wastewater through the wastewater solids separation tank (2) can enter the wastewater accumulation tank (1), the heating heat exchanger circuit (7) placed in the wastewater accumulation tank (1), the free cooling heat exchanger circuit (9) placed in the wastewater accumulation tank ( 1), in addition, the circuit of the free-cooling heat exchanger (9) is located below the circuit of the heating heat exchanger (7), the inflowing wastewater inlet valve (10), which is connected to the wastewater inlet (3) and configured to control the inflowing wastewater, the first flow valve (11) of the heating heat exchanger circuit , connected to the heating heat exchanger circuit (7) and configured to change the heating surface area of the heating heat exchanger circuit (7); the second heating heat exchanger circuit flow valve (12), connected to the heating heat exchanger circuit (7) and configured to additionally change the heating surface area of the heating heat exchanger circuit (7); a free-cooling heat exchanger circuit flow valve (13) connected to the free-cooling heat exchanger circuit (9) and configured to change the cooling surface area of the free-cooling heat exchanger circuit (9); an inflowing wastewater thermometer (14) located in the wastewater inlet (3) or in the wastewater solids separation tank (2) and configured to determine the temperature of the inflowing wastewater; a heating heat exchanger circuit thermometer (15) located near the heating heat exchanger circuit (7) and configured to determine the temperature in the area of the heating heat exchanger circuit (7); a free-cooling heat exchanger circuit thermometer (16) located near the free-cooling heat exchanger circuit (9) and configured to determine the temperature in the free-cooling heat exchanger circuit (9) area; the inflowing wastewater meter (17), which is connected to the wastewater inlet (3) and configured for accounting of the inflowing wastewater volume, the heating heat exchanger circuit heat meter (18), which is connected to the heating heat exchanger circuit (7) and configured for accounting of the instantaneous heat demand; the heat counter of the free-cooling heat exchanger circuit (19), which is connected to the free-cooling heat exchanger circuit (9) and configured to record the instantaneous cooling demand; and a control unit (20) connected to thermometers (13, 14, 15) for receiving temperature reading data and with an inflowing wastewater meter (17) for receiving incoming wastewater volume reading data, and with meters (18; 19) for instantaneous heat demand data for receiving, and with valves (5; 10; 11; 12; 13) for their control based on the data received from thermometers (13, 14, 15) and counters (17; 18; 19). 2. Indoor microclimate maintenance system according to claim 1, characterized in that the system additionally contains a sewage pump well (30) inserted between the sewage supply (31) and the sewage inlet (3) for supplying sewage to the sewage inlet (3) . 3. The indoor microclimate maintenance system according to claim 1 or 2, characterized in that the system additionally contains a thick fraction pressure pipe (32), the end of which is located in the wastewater solids separation tank (2) and contains a pump (35) , configured to discharge the separated thick fraction to the wastewater collection system (33). 4. Indoor microclimate maintenance system according to any one of claims 1 to 3, characterized in that the system additionally contains a pressurized cooling tank (34) connected to a waste water accumulation tank (1) and a waste water solids separation tank (2 ) for receiving the thick fraction separated in it, thus ensuring a decrease in wastewater pressure. 5. A control method for an indoor microclimate maintenance system according to any one of claims 1 to 4, wherein the control method includes the following steps: a) receiving the instantaneous cooling demand value (QFREE) in Joules (J) in the control unit (20) from the heat meter (19) of the free cooling heat exchanger circuit and/or receiving the instantaneous heat demand value (QHEAT) in Joules (J) in the control unit (20) from the heating heat exchanger circuit (7); b) opening the inflowing wastewater control valve (10) if the instantaneous cooling demand value (QFREE) is less than the instantaneous heat demand value (QHEAT) and closing the inflowing wastewater control valve (10) if the instantaneous cooling demand value (QFREE) is equal to or greater than the instantaneous heat demand value (QHEAT); c) setting the highest temperature threshold (TH16) and the lowest temperature threshold (TL16) for the temperature values coming from the free-cooling heat exchanger circuit thermometer (16), in addition, the highest temperature threshold (TH16) is the highest temperature in summer, above which the system must not raise the wastewater temperature in the storage tank (1), moreover, the lowest temperature threshold (TL16) is the lowest temperature in winter, below which the system must not reduce the temperature of the wastewater in the wastewater storage tank (1); d) setting the heating mode; or e) setting the cooling mode. 6. Control method according to claim 5, characterized in that the setting of the heating mode includes determining the instantaneous heat demand value (QHEAT) in the control unit (20) according to the following equation (40): QHEAT = QFREE + ((T14 - T16) * c * M) [J], where QFREE is the instantaneous cooling demand value (QFREE) [J], M - volume of wastewater inflow [kg/s], counted by the inflowing wastewater meter (17), c - heat capacity [J/kg*K], ТИ6 - temperature value [K] recorded by the circuit thermometer of the free-cooling heat exchanger (16) T14 - temperature value [K] recorded by the inflowing wastewater thermometer (14), moreover, in the heating mode, if the temperature value (T16) approaches the lowest temperature threshold (TL16), then the control unit determines the QHEAT value according to equation (40) and if the determined QHEAT value is not equal to QFREE, then the control unit (20) sends a signal to the influent control valve (10) to open it, and the influent control valve (10) is closed after the recalculation of QHEAT is equal to QFREE, and in addition temperature threshold (TII16) is 18°C (291K) and temperature threshold (TL16) is 7°C (280K). 7. The control method according to claim 5, characterized in that the setting of the cooling mode includes determining the instantaneous cooling demand value (QFREE) in the control unit (20) according to the following equation (50): QFREE = QHEAT + ((T16 - T14) * c * M) [J], where QHEAT is the value of the instantaneous heat demand (QHEAT) [J], ivi is the value of the nuicivuucnu pipiuuca volume [Kg/aj, av αζ.3ΐ\.αιι,α ivpiuaiuau iiulvauuviiu counter (17), c - heat capacity [J/kg*K], T16 - temperature value [K] recorded by the circuit thermometer of the free-cooling heat exchanger (16) T14 - the temperature value [K] recorded by the thermometer of the inflowing wastewater (14), moreover, in the cooling mode, if the temperature value (T16) approaches the highest temperature threshold (TH16) and the instantaneous cooling demand value (QFREE) is greater than the instantaneous heat demand value ( QHEAT), then the control unit (20) determines the value of QFREE according to equation (50) to open the inflow control valve (10) and close it after the condition of equation (50) is met, and in addition, the highest temperature threshold (TH16) is 18°C (29IK) and the lowest temperature threshold (TL16) is 7°C (280K).