DE102024130869A1 - System and method for heating water - Google Patents

Abstract

A system for heating water, comprising:- a circuit (2) in which an operating fluid circulates, the circuit (2) comprising a means (20) for heating the operating fluid;- a first line (31) for supplying water for sanitary use;- a second line (32) for supplying water intended for heating at least one environment of a building;- first heat exchange means (5) for exchanging heat between the circuit (2) and the first supply line (31);- second heat exchange means (4) for exchanging heat between the circuit (2) and the second supply line (32).The heating means (20) is or comprises a piston pump (21).

Description

The present invention relates to a system and a method for heating hot water to be used both for heating at least one environment of a building and for the sanitary water to be used in a building.

It is therefore a water heating system for civil use.

Building heating systems are well known. In this case, the hot water to be supplied to the convector radiators and the hot water to be used as domestic water can be obtained using a boiler that burns a fuel. An alternative solution can be a heat pump, which uses the classic elements of a reverse refrigeration cycle: a compressor acting on a fluid that is at least partially gaseous, a condenser, an evaporator, and a throttling element. The coefficient of performance (COP) of a heat pump of this type is typically less than 7. The COP is an efficiency index of a heat pump, determined by the ratio between the energy delivered (e.g., heat transferred to the environment to be heated) and the electrical energy consumed.

In this context, the technical problem underlying the present invention is to propose a system and a heating method that enable high performance while optimizing energy consumption. Another problem is to enable easy maintenance. Another problem is to provide a noiseless solution.

The defined technical task and the stated objectives are essentially achieved by a system and a heating process which are described below.

• - einen Kreislauf, in dem ein Betriebsfluid zirkuliert; wobei der Kreislauf ein Mittel zum Erwärmen des Betriebsfluids umfasst und keinen Verdampfer aufweist,
• - eine erste Leitung zum Zuführen von Wasser zur sanitären Verwendung,
• - eine zweite Leitung zum Zuführen von Wasser, das zum Heizen mindestens einer Umgebung eines Gebäudes vorgesehen ist,
• - erste Wärmeaustauschmittel zum Austauschen von Wärme zwischen dem Kreislauf und der ersten Zufuhrleitung,
• - zweite Wärmeaustauschmittel zum Austauschen von Wärme zwischen dem Kreislauf und der zweiten Zufuhrleitung.

According to a first aspect, the invention relates to a system for heating water, comprising:

• - a circuit in which an operating fluid circulates; the circuit comprising a means for heating the operating fluid and not having an evaporator,
• - a first pipe for supplying water for sanitary use,
• - a second pipe for supplying water intended for heating at least one environment of a building,
• - first heat exchange means for exchanging heat between the circuit and the first supply line,
• - second heat exchange means for exchanging heat between the circuit and the second supply line.

The system is characterized by the fact that the heating medium consists of a piston pump.

In other words, the circuit in which a working fluid circulates does not have an evaporator, and the heating means consist solely of the piston pump for heating the working fluid circulating in the circuit. As a result, no air or liquid from an external environment is required to heat the working fluid. This means that the heating of the system does not depend on the temperature of the external environment or the outside temperature.

According to a further feature, the circuit comprises an electric motor for driving the piston pump, wherein the electric motor is an asynchronous magnetic electric motor or comprises such an electric motor.

In a preferred embodiment, the operating fluid is selected from the group consisting of R1233ZD(E), R1234ZE and R295.

Advantageously, the operating fluid is R1233ZD(E), which has a global warming potential (GWP) of 5, i.e. a low greenhouse effect.

• - einen Pfad, der in sich geschlossenen ist, in dem ein Wärmeübertragungsfluid zirkuliert,
• - einen ersten Wärmetauscher, der das in dem Kreislauf zirkulierende Betriebsfluid und das in dem Pfad zirkulierende Wärmeübertragungsfluid in thermische Verbindung bringt,
• - einen Wärmeaustauschbehälter in thermischer Verbindung mit der ersten Zufuhrleitung.

According to a specific embodiment, the first heat exchange means comprises:

• - a self-contained path in which a heat transfer fluid circulates,
• - a first heat exchanger which brings the operating fluid circulating in the circuit and the heat transfer fluid circulating in the path into thermal communication,
• - a heat exchange tank in thermal communication with the first supply line.

Advantageously, the first supply line for water for sanitary use comprises a coiled pipe running inside the tank.

In this embodiment, the system advantageously comprises an additional heat exchanger for exchanging heat between the circuit and the first supply line.

Preferably, the system comprises a throttle valve arranged between the first heat exchanger and the additional heat exchanger.

The invention also relates to a method for heating water incorporating the previously disclosed system.

• - Zirkulieren des Betriebsfluids in dem Kreislauf,
• - Erwärmen des in dem Kreislauf zirkulierenden Betriebsfluids,
• - Durchführen einer Übertragung von Wärme von dem Betriebsfluid auf Wasser zur sanitären Verwendung; wobei sich das Wasser zur sanitären Verwendung entlang der ersten Zufuhrleitung bewegt;
• - Durchführen einer Übertragung von Wärme von dem Betriebsfluid auf Wasser zum Heizen mindestens einer Umgebung eines Gebäudes; wobei sich das Wasser zum Heizen entlang der zweiten Zufuhrleitung bewegt.

The procedure includes the following steps:

• - Circulating the operating fluid in the circuit,
• - Heating the operating fluid circulating in the circuit,
• - performing a transfer of heat from the operating fluid to sanitary water; wherein the sanitary water moves along the first supply line;
• - performing a transfer of heat from the operating fluid to water for heating at least one environment of a building; wherein the water for heating moves along the second supply line.

Advantageously, the operating fluid has a pressure between 6 and 8 bar and preferably always remains in the liquid phase in the circuit.

Further features and advantages of the present invention will become apparent from the exemplary and therefore non-limiting description of a preferred but not exclusive embodiment of a device as shown in 1 schematically illustrated system and a heating process more clearly.

In the accompanying figures of the drawings, reference numeral 1 denotes a system for heating water.

The system 1 comprises a circuit 2 in which an operating fluid circulates.

The operating fluid can be an HFO-based fluid (HFO = hydrofluoroolefin) such as R1366Mzz or R1233 ZD, or based on ammonia or inhibited calcium carbonate, or others. It is preferably R1233ZD(E).

Suitably, the operating fluid in circuit 2 always remains in the liquid phase and is advantageously between 6 and 8 bar.

The circuit 2 comprises a means 20 for heating the operating fluid.

Circuit 2 comprises a first line 31 for supplying water for sanitary purposes. The first supply line 31 typically receives tap water at the inlet (typically at 3 bar and 15°C). Such an inlet is located at reference numeral 310.

The system 1 comprises a second line 32 for supplying heating water to at least one environment of a building. This water is intended to flow through elements designed to distribute heat in an environment of the building (for example, convector radiators 7). The second supply line 32 is self-contained and therefore defines a recirculation line. The first and second lines 31, 32 are separate and distinct.

The numbers “first” and “second” serve to distinguish between the supply lines; they do not indicate any order or priority (the same applies to the rest of the text).

The system 1 comprises first heat exchange means 5 for exchanging heat between the circuit 2 and the first supply line 31.

The first heat exchange medium 5 comprises a closed path 50 in which a heat transfer fluid circulates (the closed path 50 is therefore a circuit). Such a heat transfer fluid always remains in the liquid state in the path 50.

The first heat exchange means 5 comprises a first heat exchanger 52, which thermally connects the operating fluid circulating in the circuit 2 and the heat transfer fluid circulating in the path 50. In a certain operating mode, the operating fluid enters the first heat exchanger 52 at a temperature between 110°C and 130°C and exits at a temperature between 30°C and 50°C. The heat transfer fluid circulating in the path 50 in such an operating mode exits the first heat exchanger 52 at a temperature above 80°C (for example, between 80°C and 90°C).

The first heat exchange means 5 comprises a heat exchange tank 53, which is in thermal communication with the first supply line 31. For example, such a tank 53 has a capacity of between 10 and 30 liters, usually 15 liters. The tank 53 also comprises an expansion tank 530. Suitably, the system 1 comprises a pump 501 (usually a centrifugal pump) for circulating the heat transfer fluid in the path 50. The pump 501 is located downstream of the first heat exchanger 52 and upstream of the tank 53.

In particular, the first line 31 for supplying water for sanitary use comprises a coil 311 extending inside the tank 53. The heat transfer fluid is present in the tank 53 and flows around the coil 311 from the outside. In the operating mode described above, the sanitary water exiting the tank 53 suitably has a temperature between 55°C and 65°C. Suitably, a temperature sensor 531 is located on the tank 53 to measure the temperature of the heat transfer fluid.

Advantageously, the system comprises an additional heat exchanger 54 through which the service fluid and the water for sanitary purposes flow. Suitably, the additional heat exchanger 54 performs the function of a preheater for the sanitary water (before it enters the tank 53 or the pipe coil 311 present in the tank 53). The exchanger 54 is located upstream of the tank 53 in the flow direction of the sanitary water. The first exchanger 52 and the additional exchanger 54 are arranged at a distance from each other.

Suitably, the circuit 2 comprises a throttle valve 23 arranged between the heat exchanger 52 and the additional heat exchanger 54. The throttle valve 23 is located at the inlet to the additional heat exchanger 54. Suitably, the throttle valve 23 can receive a control input as a function of the pressure downstream of the additional heat exchanger 54.

As in 1 As shown by way of example, the first heat exchanger 52, the second heat exchanger 55 and the additional heat exchanger 54 are arranged in series along the circuit 2. The first exchanger 52 is arranged downstream of the second exchanger 55 and upstream of the additional exchanger 54.

The system 1 comprises second heat exchange means 4 between the circuit 2 and the second supply line 32. The second heat exchange means 4 is, for example, a second heat exchanger 55, typically a plate exchanger, or comprises such an exchanger. They define an area in which the circuit 2 and the second supply line 32 are in thermal contact. The second exchanger 55 therefore influences both the circuit 2 and the second supply line 32. For example, the operating fluid could enter the second heat exchange means 4 at a temperature between 150 and 130°C and exit it at a temperature between 130°C and 110°C. Suitably, the heating water of at least one environment of the building exits the exchanger at a temperature between 80 and 90°C.

Suitably, the operating fluid and the heating water of at least one environment of a building are in counterflow in the second heat exchange medium 4.

A temperature sensor 321 is placed along the second line 32.

The system 1 includes a water circulation pump 322 along the second line 32. The water circulation pump 322 is typically a centrifugal pump. It enables water to be circulated along the second line between the second heat exchange medium and the convector heaters 7.

The heating means 20 is a piston pump 21. Typically, this is a high-pressure piston pump 21. The system 1 can be considered a heat pump in the sense that it has a COP of over 7, preferably over 10. The COP (Coefficient of Performance) is an efficiency indicator of a heat pump and is determined by the ratio between the energy delivered and the electrical energy consumed. However, unlike a conventional heating pump, the system of the invention does not include an evaporator.

The pump 21 thus heats the operating fluid. This occurs due to the compression effect on the incompressible operating fluid. Such compression forces the operating fluid along the channels of the pump 21, causing an increase in its kinetic energy and its heating through friction.

Suitably, the circuit 2 comprises only the piston pump 21 for heating the operating fluid circulating therein.

Considered in isolation, the piston pump 21 is a positive displacement pump of a known type. The piston pump could be an axial piston pump, but also a piston pump of a different type. For example, it includes pistons housed in corresponding pumping chambers. The pumping chambers are conveniently integrated into a body that can be rotated. The rotation of this body and therefore of the pumping chambers causes the pistons to rotate and therefore establishes an alternating reciprocating movement of the pistons in the corresponding pumping chambers. In fact, one end of the pistons is pressed by elastic means against a plate which is inclined with respect to the axis of rotation of the pumping chambers.

The system 1 includes an electric motor 22 for driving the piston pump 21. The electric motor 22 is preferably a magnetic asynchronous electric motor 22 or comprises one. This contributes to the quietness of the system 1. Suitably, the motor 22 includes an inverter. The operation of the motor 22 is also controlled depending on the feedback provided by the temperature sensors 321 placed along the second line 32.

The additional heat exchanger 54 is arranged between the first exchanger 52 and the piston pump 21.

The system 1 may comprise a filter 61, an inspection port 62, and a liquid collector 63. Suitably, they are arranged downstream of the first exchanger 52 and upstream of the additional heat exchanger 54.

The system 1 suitably comprises a soundproof housing in which the piston pump 21 is housed.

The system 1 also comprises a control unit for controlling the overall operation and for regulating the required temperatures and pressures required to keep the operating fluid circulating in the circuit 2 in a liquid phase.

Another object of the present invention is a method for heating water.

The method is advantageously implemented by a system 1 having one or more of the features described above.

• - Zirkulieren eines Betriebsfluids in einem Kreislauf 2; geeigneterweise bleibt ein derartiges Betriebsfluid stets eine Flüssigkeit, die in dem Kreislauf 2 zirkuliert (es könnte daher auch als Betriebsflüssigkeit bezeichnet werden);
• - Erwärmen des in dem Kreislauf 2 zirkulierenden Betriebsfluids.

The procedure includes the following steps:

• - circulating an operating fluid in a circuit 2; suitably, such operating fluid always remains a liquid circulating in the circuit 2 (it could therefore also be referred to as an operating fluid);
• - Heating the operating fluid circulating in circuit 2.

The step of heating the operating fluid flowing through the circuit 2 occurs as the operating fluid passes through a piston pump 21 placed along the circuit 2. Therefore, the piston pump 21 heats the operating fluid. Suitably, the operating fluid is liquid at least at the pump 21 (but preferably everywhere). The piston pump 21 acts on the operating fluid so that the pressure of the operating fluid is, for example, between 6 and 8 bar when R1233ZD(E) is used. In some embodiments, the piston pump 21 acts on the operating fluid, causing a pressure increase of at least 10 bar and/or a temperature increase of at least 90°C. Downstream of the piston pump 21, operating fluid temperatures even higher than 110°C or 120°C can be achieved. The pump 21 not only heats the operating fluid but is also solely responsible for its movement.

The method comprises the step of performing a heat transfer from the operating fluid present in circuit 2 to sanitary water. Typically, a flow rate of between 12 and 16 liters/minute is provided. The sanitary water moves along a first supply line 31. Such heat transfer from the operating fluid present in circuit 2 to the sanitary water occurs indirectly.

In fact, it provides for a transfer of heat between the working fluid circulating in the circuit 2 and the heat transfer fluid circulating in a closed path 50, as well as the transfer of heat from the heat transfer fluid circulating in the closed path 50 to water for sanitary use flowing along the first conduit 31.

• - einen Behälter 53, in dem das Wärmeübertragungsfluid vorhanden ist;
• - einen Abschnitt der ersten Leitung 31, der in dem Behälter 53 verläuft.

The transfer of heat from the circulating heat transfer fluid in the closed path 50 to the water for sanitary use flowing along the first conduit 31 takes place in a heat exchanger, which preferably comprises:

• - a container 53 in which the heat transfer fluid is present;
• - a section of the first line 31 which runs in the container 53.

Typically, such a section defines a coil 311. Suitably, the coil 311 is embedded in the heat transfer fluid present in the vessel 53. The heat transfer fluid is liquid. For example, it may be of the same type as the operating fluid.

The first line 31 is a path that runs between a tap water inlet zone and one or more taps that provide the user with water (usually in the form of running water).

The method further comprises the step of transferring heat from the operating fluid present in the circuit 2 to water for heating at least one environment of a building. This is done, for example, by second heat exchange means 4. Typically, the second heat exchange means 4 comprises a plate heat exchanger.

The heating water moves along a second supply line 32. In particular, the secondary line 32 runs in a circular pattern. Therefore, the heating water absorbs the heat, reaches the convector radiator(s) 7 to heat at least one environment of the building, and then flows back to be reheated.

The present invention achieves important advantages.

First, it allows for significant heating power, perfectly compatible with that associated with heating at least part of a building and heating domestic water. Furthermore, it allows for easier maintenance.

Furthermore, it is possible to obtain a compact and silent solution. xxx The invention, as conceived, is susceptible to numerous modifications and variations, all of which fall within the scope of the inventive concept characterized thereby. Furthermore, all details can be replaced by other technically equivalent elements. In practice, all materials used, as well as the dimensions, can be any, as required.

Claims (10)

A system for heating water, comprising: - a circuit (2) in which an operating fluid circulates; the circuit (2) comprising a means (20) for heating the operating fluid and not having an evaporator, - a first line (31) for supplying water for sanitary use, - a second line (32) for supplying water intended for heating at least one environment of a building, - first heat exchange means (5) for exchanging heat between the circuit (2) and the first supply line (31); - second heat exchange means (4) for exchanging heat between the circuit (2) and the second supply line (32); characterized in that the heating means (20) consists of a piston pump (21). System according to Claim 1 , characterized in that it comprises an electric motor (22) for driving the piston pump (21); wherein the electric motor (22) is or comprises an asynchronous magnetic electric motor (22). System according to one of the preceding claims, characterized in that the operating fluid is R1233ZD(E). System according to one of the preceding claims, characterized in that the first heat exchange means (5) comprises: - a path (50) which is closed in itself, in which a heat transfer fluid circulates, - a first heat exchanger (52) which brings the operating fluid circulating in the circuit (2) and the heat transfer fluid circulating in the path (50) into thermal communication, - a heat exchange tank (53) in thermal communication with the first supply line (31). System according to Claim 4 , characterized in that the first supply line (31) of the water for sanitary use comprises a coil pipe (311) which runs inside the container (53). System according to Claim 5 , characterized in that it comprises an additional heat exchanger (54) for exchanging heat between the circuit (2) and the first supply line (31). System according to Claim 6 , characterized in that it comprises a throttle valve (23) arranged between the first heat exchanger (52) and the additional heat exchanger (54). System according to one of the preceding claims, characterized in that it comprises a control unit for regulating the temperatures and pressures required to maintain the operating fluid circulating in the circuit 2 in a liquid phase. Method for heating water using the system according to one of the Claims 1 until 8 , comprising the following steps: - Circulating an operating fluid in a circuit (2), - Heating the operating fluid (2) circulating in the circuit, - Carrying out a transfer of heat from the operating fluid to water for sanitary use; wherein the water for sanitary use moving along a first supply line (31), - performing a transfer of heat from the operating fluid to water for heating at least one environment of a building; wherein the water for heating moves along a second supply line (32). Procedure according to Claim 9 , characterized in that the operating fluid has a pressure between 6 and 8 bar.

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