EE01530U1 - A combined system of service water heating and a heating medium for domestic heating - Google Patents

Abstract

A combined system (21) of service water heating and heating medium for domestic heating comprises at least two independent heating medium sources, such as a boiler unit (1) and/or a solar panel system (12) or a heat pump and the like, by means of primary circuits (24, 25) connected in parallel to the combined system (21) by means of a plate heat exchanger (22), and in parallel connected circuits collecting heat from the heating medium, on one hand for the domestic heating system circuit (11) and on the other hand, the circuit (23) for heating of service water with the interface through its own heat exchanger (8), while the said parallel circuits (23, 11, 24, 25), including their backflow sections, are interconnected via plate heat exchangers (8, 22) to concentrate in the combined system block (21) and are mutually variously switchable, in particular depending on the different levels of achieved temperatures of at least two stratified layers of heating media in an external heat storage tank (20), connected in parallel by means of a differential connection of a three-way valve group (16, 17, 18, 19) with inputs/outputs to circuits (23, 11, 24, 25), preferably through the input/output (27) in the external tank (20) for the domestic heating circuit (11) and through the input/output (26) in the external tank (20) for heating of service water, primarily to the heating circuit (23) of the service water from the top layer of the heating medium by means of mixing three-way valves (17, 7) for differential switching either to a service water heating circuit (23) not exceeding 55° C, or to a domestic heating circuit (11) with a temperature even above 55° C.

Description

 Technical field

The invention relates to a combined system for heating domestic water and heating heat carrier, which includes at least two independent heating sources, for example a boiler unit (stationary boiler) and/or a solar panel system or a heat pump, etc., further including primary circuits connected to the combined system in parallel via heat exchangers, in particular plate-type heat exchangers, and at least two parallel-connected flow circuits that collect heat from the heating medium, on the one hand for the domestic heating system and on the other hand for indirectly heating domestic water via its heat exchanger interface.

Technical level

Heating systems or systems that use thermal energy from a combustion boiler to heat living spaces as well as, for example, to heat sanitary or service water, such as shower water, bath water, etc., are known in the art.

Such heating systems include a primary heat exchanger installed on the boiler, through which a heat exchange fluid, usually water, flows, which circulates through radiators in the heated rooms under the pressure of a corresponding circulation pump.

A three-way flow diverter valve is usually installed on the outlet pipe of the heating medium from the boiler, which allows the radiators to alternatively use the hot fluid from the secondary heat exchanger. This secondary heat exchanger allows the heating of domestic water for distribution to the sanitary equipment of the living spaces, removing heat directly from the heating medium and thus using the thermal energy of the boiler.

However, the three-way flow switching valve in known systems is not able to differentially distribute the flow of hot heat carrier between the radiator circuit and the secondary heat exchanger circuit. Said valve is controlled by binary logic and can have only two extreme positions, i.e. one for supplying the radiators in case the domestic users do not need hot water, and the other for supplying the secondary heat exchanger in case hot water is needed. The valve switching command is issued by the corresponding control means when a minimum flow sensor attached to the sanitary water pipe detects a certain need for heated domestic or sanitary water, for example 2.5 l/m.

This type of heating system allows the boiler's thermal energy to be used for two purposes, both for home heating and for domestic hot water, but on the other hand it often causes significant energy losses. When there is minimal demand for domestic water, the heating of the radiators in the living spaces is usually also stopped, so that all and excess heat is spent only on heating a small amount of water.

The main objective of the present invention is to overcome the known disadvantages of the known arrangement of heating flow control devices in combined heating systems for sanitary or primary domestic water in residential premises and indirect heating of fresh water, by creating a combined system that simplifies on-site installation while maximizing energy savings with the best possible technology and control.

Summary of the invention

According to the invention, the objectives and effects are achieved by a combined system for heating fresh water and domestic heating heat carrier, which includes at least two independent heat carrier sources, such as a boiler unit and/or a solar panel system or a heat pump, etc., by means of primary circuits connected to the combined system in parallel with a plate heat exchanger and a parallel connected

by means of circuits that collect heat from the heat carrier, both for heating the domestic heating system and for heating the domestic water by means of a conventional heat exchanger connected via an interface, while said parallel flow circuits, including their return sections, are interconnected via plate heat exchangers to form a combined system block and are mutually switchable with each other, in particular depending on the different temperature levels of the temperatures of at least two heating layers of the heat carrier in an external heat storage tank, which is connected via a different connection method of a three-way valve group to the inputs/outputs in parallel, preferably via the input/output of the external tank of the domestic heating circuit and via the input/output of the external tank for heating the domestic water, in particular from the upper layer of the heat carrier to the domestic water heating circuit, this via different switching of the three-way valves either to the domestic water heating circuit, the temperature of which does not exceed 55 °C, or to the domestic heating circuit, the temperature of which even exceeds 55 °C.

According to the invention, the external tank includes inputs/outputs connected to the low temperature layer of the heat carrier and connected to a three-way valve and a domestic water heating circuit or a domestic heating circuit via a three-way valve, minimizing the input heat energy and minimizing heat losses.

Preferably, when rapid heating of domestic hot water is required, the domestic hot water heating circuit is equipped with a flow switch to activate indirect flow of mixing valves located in the branch of the heating medium circuit flowing from the external tank through the outlet, with its own plate heat exchanger for selective connection to the upper layers of the heating medium in the external tank.

Description of reference numbers and drawing

Further advantages and features of the present invention will become apparent from the drawing, in which the sole illustration is a schematic block diagram of a combined heating system for domestic water and domestic heating heat carrier.

Examples of embodiments of the invention

The domestic hot water heating and home heating heat carrier system includes at least two independent heat carrier sources, such as a boiler unit 1 and/or a solar panel system 12 or a heat pump or the like, comprising primary circuits 24, 25 connected to a plate heat exchanger 22 indirectly in parallel with the combined system 21, and circuits connected in parallel with the heat carrier for collecting heat, on the one hand for the home heating system circuit 11 and on the other hand for the domestic hot water heating circuit 23 via the interface of its own heat exchanger 8.

Said parallel circuits 23, 11, 24, 25, including their return sections, are interconnected via plate heat exchangers 8, 22 for accumulation in the combined system block 21 and are mutually switchable in various ways, depending in particular on the different levels of temperatures reached in at least two layers of the stratified heat carrier in the external heat storage tank 20, being connected in parallel to a group of three-way valves 16, 17, 18, 19 via different connections to the inputs/outputs of the circuits 23, 11, 24, 25, preferably via input/output 27 to the domestic heating circuit 11 in the external tank 20 and via input/output 26 in the external tank 20 for heating domestic water, in particular from the upper layer of the heat carrier to the domestic water heating circuit 23 by different switching of the three-way valves 17, 7 either to the domestic water heating circuit 23 for connection without exceeding 55 °C, or for connection to the domestic heating circuit 11 even with a temperature exceeding 55 °C.

The external tank 20 includes inputs/outputs 28, 29, which are connected to the lower temperature layer of the heat carrier via a three-way valve 18, 19 and connected to the domestic hot water circuit 23 or the domestic heating circuit 11 via a three-way mixing valve 5, minimizing the input heat energy and minimizing heat losses.

The domestic water heating circuit 23 includes a flow switch 9 from the external tank 20 and the outlet 26 through the heat carrier mixing valves 5, 7 to its own plate heat exchanger 8 to activate priority flow when domestic water consumption is required.

The function of the combined system 21 varies to various degrees as described hereinafter, while it is assumed that a brief description of these functions will be clearly understood by those skilled in the art.

Domestic water heating (FriWa)

The electronically controlled mixing valve 5 equipped with an actuator with an extremely fast response time directs the preheated heat carrier in the domestic water heating circuit 23 with the pump 6 from the external tank 20 via the input/output 26, while maintaining the heat carrier temperature below 50 °C, towards the heat exchanger 8, in order to prevent scaling of the stainless steel plates in this heat exchanger 8 if calcium deposition occurs at temperatures below 55 °C.

The domestic water temperature is measured by a fast-reacting sensor 9 and is set to the required outlet temperature using an electronically controlled mixing controller, for example a three-way valve 7 downstream of the plate heat exchanger 8. This also eliminates fluctuations in the domestic water temperature in circuit 23. Domestic water heating starts when sensor 9 or another sensor equipped with a built-in flow sensor registers the need for domestic water consumption.

The main part of the domestic water circuit 23 after the plate heat exchanger 8 is optionally equipped with a circulation pump 10 with a feedback loop and a temperature X measuring sensor S3 not exceeding 55 °C, while in this part of the circuit 23 there is a hydraulic connection with a minimum amount of domestic water, which effectively prevents the growth of legionella in the domestic water, while the corresponding inlet pipes are already pre-installed in the system.

The domestic water circulation pump 10 can be set to operate on demand. In this case, a hydraulic coupling occurs, as shown in the diagram. The corresponding inlet pipes are pre-assembled.

Sensor S3 measures the temperature of the return water in this feedback loop and switches off the domestic water circulation pump 10 when the heated domestic water starts to circulate again in the main circuit 23, using the energy saving method described above.

Mixing the heat carrier in a home heating system

The same electronically controlled mixing circuit as was used for preparing domestic water has been used to generate the required calculated temperature of the heat carrier to be fed into the radiator/floor heating system based on the ambient temperature (or room temperature).

The direction of flow of the heat carrier is switched via a three-way valve 7, whereby a sensor S1 is used to control the temperature of the incoming heat carrier and its flow.

The heat carrier is taken out through the inlet/outlet 27 to maintain the temperature above the inlet/outlet 27 temperature of the external tank 20 in order to heat the domestic water arriving from the inlet/outlet 26.

A speed controller can be used to set the flow rate of the circulation pump 6 to prevent it from creating noise in the mixing circuit system or in the home heating circuit 11 and at the same time to save electrical energy.

Solar device

Heat transfer from the antifreeze coming from the collectors 12 to the heat carrier flowing into the external tank 20 is carried out via a plate heat exchanger 22, because it has a much larger heat exchange surface area than a conventional tubular heat exchanger installed in a tank, which is used with conventional solar panels.

The correct stratification of the heat in the tank 20 is achieved by the valve 16 in the direction of the inlet/outlet 26 or 27, since the temperature in the collector 12 varies greatly.

The volume flow of the circulation pumps 13 and 14 is controlled by the controller 15, ensuring optimal and uniform heat accumulation from the collector 12. The measurement and evaluation of the heat quantity is carried out by the regulator 15, which uses a volume flow sensor.

Heat generator

A regulator not shown in the diagram, such as a room thermostat, is used to control the required amount of heat produced by a heat source that is not located in the home, such as a boiler 1 that burns, for example, oil, gas, or a heat pump.

Other automatic heating furnaces suitable for continuous energy production may be connected directly to the external tank 20 with indirect stratification of inputs/outputs 26, 28 and controlled by a controller in flow contact.

Heat sources not controlled by the system can be connected to the external tank 20 via inputs/outputs 26, 29.

For gas baths, wall-mounted heaters and distributed heat pumps, it is recommended to use an additional heat exchanger for these unregulated heat sources,

however, it is usually necessary to use an additional valve 4 to prevent short-circuited or transverse flow through such a heat exchanger.

The heated heat carrier enters the controller-calculated layer of the external tank 20 via the switching valve 17 through the inputs/outputs 26 or 27. The temperature of the heated heat carrier from these sources is controlled by a sensor not shown in the figure and is removed, for example, by a flow-controlled circulation pump.

Layering in an outdoor container

- The three-way valve 16 switches at the temperature measured by the sensor S4, while the collector 12 produces energy to the external tank 20 via the inputs/outputs 26, 27 of the external tank 20,

- the three-way valve 17 switches during the production of domestic hot water using FriWa and/or in the direction of the input/output 26 from the boiler 1 during the “up” filling of the external tank 20,

- the three-way valve 17 switches to the input/output 27 position in the external tank 20 when the home heating distribution system (FBH, radiators, etc.) and/or the boiler 1 must remain at the required input temperature given by the sensor S1,

- the three-way valve 18 switches in the input/output direction 26 from the boiler 1 during the “up” filling of the external tank 20, preventing “unnecessary” filling of the external tank 20,

- the three-way valve 18 switches to the input/output 28 position in the external tank 20 if the home heating distribution system (FBH, radiators, etc.) and/or the boiler 1 must remain at the required input temperature given by the sensor Sl at the input/output 17 level in the external tank 20, preventing unnecessary “charging” of the external tank 20, - the three-way valve 18 switches to the input/output 29 position in the external tank 20 if the measured temperature of the return heat carrier of all mixing circuits in the system 21 must be lower than that at the boiler 1 and no heat is produced at the input/output 28 level of the external tank 20.

Claims (3)

1. A combined system (21) for domestic hot water heating and domestic heating heat carrier, comprising at least two independent heat carrier sources, such as a boiler unit (1) and/or a solar panel system (12) or a heat pump, etc., via primary circuits (24, 25) connected to the combined system (21) in parallel via a plate heat exchanger (22) and parallel-connected circuits that collect heat from the heat carrier, on the one hand for the domestic heating system circuit (11) and on the other hand via a dedicated heat exchanger (8) via an interface for domestic hot water heating for the circuit (23), characterised in that said parallel circuits (23, 11, 24, 25), including their return sections, are connected to each other via plate heat exchangers (8, 22) to form a combined system block (21) and are switchable with each other, in particular depending on the at least two stratified heating layers of the heat carrier from different temperature levels in the external heat storage tank (20), which is connected via a different connection method of the three-way valve group (16, 17, 18, 19) to the inputs/outputs (23, 11, 24, 25) of the circuits in parallel, preferably via the input/output (27) of the external tank (20) of the domestic heating circuit (11) and via the input/output (26) of the external tank (20) for domestic water heating, in particular from the upper layer of the heat carrier to the domestic water heating circuit (23), this via different switching of the three-way valves (17, 7) either to the domestic water heating circuit (23), the temperature of which does not exceed 55 °C, or to the domestic heating circuit (11), the temperature of which even exceeds 55 °C. 2. Combined system (21) according to claim 1, characterized in that the external tank (20) includes inputs/outputs (28, 29) connected to the low temperature layers of the heat carrier and connected via a three-way valve (18, 19) and a three-way mixing valve (5) to a circuit (23) for heating domestic water or to a circuit (11) for domestic heating, minimizing the input heat energy and minimizing heat losses. 3. Combined system (21) according to claim 1, characterized in that the circuit (23) for heating domestic water includes a flow switch (9) for activating the preferential flow of the heat carrier from the external tank (20) and the outlet (26) through the mixing valves (5, 7) to its own plate heat exchanger (8) in case of demand for domestic water.