Water heating system and method

Abstract

To provide a system and a method for heating warm water to be used both for heating (warming) at least one environment of a building, and for hygienic water to be used in the building.SOLUTION: A system for heating water comprises: a circuit (2) in which working fluid is circulated, and including heating means (20) for heating the working fluid; a first supply line (31) for supplying hygienic water; a second supply line (32) for supplying water 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); and second heat exchange means (4) for exchanging heat between the circuit (2) and the second supply line (32). The heating means (20) comprises a piston pump (21).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a system and method for heating hot water used both for heating (warming) at least one environment of a building and for sanitary water used in the building.

[0002] Therefore, this is a domestic water heating system.

Background Art

[0003] Building heating systems are known. In this case, the hot water sent to the convection heater and the hot water used as sanitary water can be obtained by a boiler that burns fuel. As an alternative solution, a heat pump can be used, and in this heat pump, classical elements of a reverse refrigeration cycle, namely, a compressor, a condenser, an evaporator, and a throttling member that act on at least partially gaseous fluid, are used. The coefficient of performance (COP) of this type of heat pump is usually less than 7. The COP is an efficiency index of the heat pump and is given by the ratio of the delivered energy (for example, the heat transferred to the environment to be heated) to the consumed electrical energy.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In this context, the technical problem underlying the present invention is to propose a system and a heating method that enable high performance and at the same time optimize energy consumption. Another object is to facilitate maintenance. A further object is to provide a noise-free solution.

Means for Solving the Problems

[0005] The defined technical problem and specific objects are substantially achieved by the system and heating method described below.

[0006] According to a first aspect, the present invention relates to a system for heating water, the system is A circuit in which a working fluid circulates, which includes means for heating the working fluid but does not include an evaporator, The first line supplying sanitary water, A second line for supplying water to heat at least one environment in the building, A first heat exchange means for exchanging heat between the circuit and the first supply line, The system comprises a second heat exchange means for exchanging heat between the circuit and the second supply line.

[0007] This system is characterized by its heating mechanism consisting of a piston pump.

[0008] In other words, the circuit through which the working fluid circulates does not include an evaporator, and the heating means consists solely of a piston pump that heats the working fluid circulating within the circuit. As a result, heating of the working fluid does not require air or liquid from the external environment. This means that the heating of the system is independent of or does not depend on the external temperature.

[0009] According to another feature, the circuit comprises an electric motor for driving the piston pump, and the electric motor comprises an asynchronous magnetoelectric motor or is an asynchronous magnetoelectric motor.

[0010] In a preferred embodiment, the working fluid is selected from the group consisting of R1233ZD(E), R1234ZE, and R295.

[0011] More advantageously, the working fluid is R1233ZD(E), which has a Global Warming Potential (GWP) of 5, meaning it has a low greenhouse effect.

[0012] According to a particular embodiment, the first heat exchange means is A closed path through which heat transfer fluid circulates, A first heat exchanger that thermally connects the working fluid circulating within the circuit with the heat transfer fluid circulating within the path, The system comprises a heat exchange tank that is thermally connected to the first supply line.

[0013] More advantageously, the first water supply line for hygienic use includes a coil that passes through the inside of the tank.

[0014] In this embodiment, the system advantageously includes an additional heat exchanger for exchanging heat between the circuit and the first supply line.

[0015] The system preferably includes a throttle valve inserted between the first heat exchanger and the additional heat exchanger.

[0016] The present invention also relates to a method for heating water, including the system disclosed above.

[0017] This method, The working fluid is circulated within the circuit. The working fluid circulating within the circuit is heated, Heat is transferred from the working fluid to the sanitary water, and the sanitary water moves along the first supply line. The process includes transferring heat from the working fluid to water for heating at least one environment in a building, the water for heating moving along a second supply line.

[0018] More advantageously, the working fluid has a pressure of 6-8 bar and preferably remains in the liquid phase at all times within the circuit.

[0019] Further features and advantages of the present invention will become more apparent from the preferred but non-exclusive, and therefore non-limiting, description of the systems and heating methods, as schematically shown in Figure 1. [Brief explanation of the drawing]

[0020] [Figure 1]In the attached drawings, reference numeral 1 indicates a system for heating water.

Embodiment for Carrying Out the Invention

[0021] System 1 comprises a circuit 2 through which a working fluid circulates.

[0022] The working fluid can be a hydrofluoroolefin-based (HFO) fluid such as R1366Mzz or R1233ZD, or can be based on ammonia or precipitated calcium carbonate or still others. This is preferably R1233ZD(E).

[0023] Suitably, the working fluid in circuit 2 always remains in the liquid phase, preferably between 6 and 8 bar.

[0024] Circuit 2 includes means 20 for heating the working fluid.

[0025] Circuit 2 includes a first line 31 for supplying water for sanitary purposes. The first supply line 31 typically receives tap water (typically at 3 bar and 15 °C) as an input. Such an input is indicated by reference numeral 310.

[0026] System 1 comprises a second line 32 for supplying heating water for at least one environment of a building. This is water intended to pass through an element (e.g., convection heater 7) adapted to dissipate heat within the environment of the building. The second supply line 32 is itself closed and thus defines a circulation line. The first and second lines 31, 32 are separated and distinct.

[0027] Note that the numerical adjectives "first" and "second" are used in advance only for distinguishing the supply lines and do not indicate order or priority (the same applies hereinafter).

[0028] System 1 includes a first heat exchange means 5 for exchanging heat between circuit 2 and the first supply line 31.

[0029] The first heat exchange means 5 comprises a closed path 50 in which a heat transfer fluid circulates (therefore, the closed path 50 is a circuit). The heat transfer fluid in such a path 50 remains in liquid form at all times.

[0030] The first heat exchange means 5 includes a first heat exchanger 52 that thermally connects a working fluid circulating in the circuit 2 with a heat transfer fluid circulating in the path 50. In a particular operating mode, the working fluid flows into the first exchanger 52 at a temperature between 110°C and 130°C and flows out at a temperature between 30°C and 50°C. In such an operating mode, the heat transfer fluid circulating in the path 50 flows out of the first exchanger 52 at a temperature above 80°C (for example, between 80°C and 90°C).

[0031] The first heat exchange means 5 comprises a heat exchange tank 53 that is thermally connected to the first supply line 31. For example, such a tank 53 has a capacity of 10 to 30 liters, typically 15 liters. The tank 53 also comprises an expansion vessel 530. Preferably, the system 1 includes a pump 501 (typically a centrifugal pump) for circulating the heat transfer fluid in the path 50. The pump 501 is located downstream of the first exchanger 52 and upstream of the tank 53.

[0032] Specifically, a first line 31 supplying sanitary water has a coil 311 that passes through a tank 53. A heat transfer fluid is present in the tank 53 and wraps around the outside of the coil 311. Preferably, in the above operating mode, the sanitary water flowing out of the tank 53 is at a temperature between 55°C and 65°C. Appropriately, the tank 53 has a temperature probe 531 which measures the temperature of the heat transfer fluid.

[0033] Advantageously, the system includes an additional heat exchanger 54 through which the working fluid and sanitary water pass. Preferably, the additional heat exchanger 54 performs the function of a preheater for the sanitary water (before the sanitary water enters the tank 53, or rather before it enters the coil 311 present in the tank 53). The exchanger 54 is located upstream of the tank 53 in the direction of sanitary water flow. The first exchanger 52 and the additional exchanger 54 are spaced apart from each other.

[0034] Preferably, circuit 2 includes a throttle valve 23 inserted between heat exchanger 52 and the additional heat exchanger 54. The throttle valve 23 is located on the input side to the additional heat exchanger 54. Preferably, the throttle valve 23 can receive a control input as a function of the pressure downstream of the additional heat exchanger 54.

[0035] As illustrated in Figure 1, the first heat exchanger 52, the second heat exchanger 55, and the additional exchanger 54 are arranged in series along the circuit 2. The first exchanger 52 is downstream of the second exchanger 55 and upstream of the additional exchanger 54.

[0036] System 1 includes a second heat exchange means 4 between circuit 2 and a second supply line 32. The second heat exchange means 4 includes, for example, a second heat exchanger 55, typically a plate heat exchanger. These define the area where circuit 2 and the second supply line 32 are in thermal contact. Thus, the second exchanger 55 affects both circuit 2 and the second supply line 32. For example, a working fluid can flow into the second heat exchange means 4 at a temperature of 150-130°C and out of the second heat exchange means 4 at a temperature of 130-110°C. Preferably, heated water from at least one environment of the building flows out of the exchanger at a temperature of 80-90°C.

[0037] Preferably, the working fluid and heating water of at least one environment in the building are in counterflow within the second heat exchange means 4.

[0038] A temperature probe 321 is positioned along the second line 32.

[0039] System 1 includes a water circulation pump 322 along a second line 32. The water circulation pump 322 is typically a centrifugal pump. This allows water to be circulated along the second line between the second heat exchange means and the convection heater 7.

[0040] The heating means 20 is a piston pump 21. Typically, it is a high-pressure piston pump 21. System 1 can be considered a heat pump in the sense that it has a COP greater than 7, preferably greater than 10. COP (Coefficient of Performance) is an efficiency index of a heat pump, given by the ratio of energy delivered to electrical energy consumed. Nevertheless, in contrast to a standard heating pump, the system of the present invention does not include an evaporator.

[0041] Consequently, the pump 21 heats the working fluid. This occurs due to the compressive action on the incompressible working fluid. This compression biases the working fluid along the duct of the pump 21, increasing its kinetic energy and heating it through friction.

[0042] Ideally, circuit 2 includes only the piston pump 21 for heating the working fluid circulating therein.

[0043] The piston pump 21, considered in itself, is a known type of positive displacement pump. The piston pump may be an axial piston pump, or it may be another type of piston pump. For example, the piston pump has a piston housed in a corresponding pump chamber. The pump chamber is conveniently integrated with a rotatable body. The rotation of this body, and therefore the rotation of the pump chamber, rotates the piston, thereby determining the alternating back-and-forth motion of the piston within the corresponding pump chamber. In fact, one end of the piston is pressed by an elastic means against a plate inclined with respect to the rotation axis of the pump chamber.

[0044] System 1 includes an electric motor 22 for driving a piston pump 21. The electric motor 22 preferably includes or is a magnetic asynchronous electric motor 22. This makes System 1 noise-free. Preferably, the motor 22 includes an inverter. The operation of the motor 22 is also tuned as a function of feedback provided by a temperature probe 321 positioned along a second line 32.

[0045] An additional exchanger 54 is interposed between the first exchanger 52 and the piston pump 21.

[0046] System 1 comprises a filter 61, an inspection port 62, and a liquid receptacle 63. Preferably, these are located downstream of the first exchanger 52 and upstream of an additional heat exchanger 54.

[0047] System 1 appropriately includes a soundproof casing for housing the piston pump 21.

[0048] Furthermore, System 1 includes a control unit that controls the overall operation and adjustment of the temperature and pressure necessary to maintain the working fluid circulating within Circuit 2 in the liquid phase.

[0049] The present invention also aims to provide a method for heating water.

[0050] This method is advantageously carried out by a system 1 having one or more of the above characteristics.

[0051] This method, A step of circulating a working fluid within circuit 2, wherein, appropriately, this working fluid remains a liquid circulating within circuit 2 at all times (and therefore may also be called a working fluid), The process includes heating the working fluid circulating within circuit 2.

[0052] The heating of the working fluid as it passes through circuit 2 occurs when it passes through a piston pump 21 located along circuit 2. This causes the piston pump 21 to heat the working fluid. Preferably, at least in the pump 21 (but preferably everywhere), the working fluid is a liquid. The piston pump 21 acts on the working fluid so that the pressure of the working fluid is 6-8 bar, for example, when R1233ZD(E) is used. In some embodiments, the piston pump 21 acts on the working 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, working fluid temperatures higher than 110°C or 120°C can be obtained. In addition to causing heating of the working fluid, the pump 21 also causes its movement.

[0053] The method includes a step of transferring heat from the working fluid present in circuit 2 to the sanitary water. Typically, a flow rate of 12 to 16 liters / minute is assumed. The sanitary water moves along the first supply line 31. This heat transfer from the working fluid present in circuit 2 to the sanitary water is performed indirectly. In practice, heat transfer is assumed between the working fluid circulating in circuit 2 and the heat transfer fluid circulating in the closed path 50, and heat transfer from the heat transfer fluid circulating in the closed path 50 to the sanitary water transported along the first line 31.

[0054] In transport along the first line 31, heat transfer from the heat transfer fluid circulating in the closed path 50 to the sanitary water takes place in a heat exchanger, which is preferably Tank 53 containing heat transfer fluid, It comprises a section of the first line 31 that passes through the tank 53.

[0055] Typically, such a section defines a coil 311. Preferably, the coil 311 is embedded in a heat transfer fluid present in the tank 53. The heat transfer fluid is a liquid. This can be, for example, the same type as the working fluid.

[0056] The first line 31 is a winding path that runs between the water supply zone and one or more taps that allow users to make water available (typically in the form of running water).

[0057] This method also includes the step of transferring heat from the working fluid present in the circuit 2 to water in order to heat (heat) at least one environment in the building. This is done, for example, by a second heat exchange means 4. Typically, the second heat exchange means 4 includes a plate heat exchanger.

[0058] The heating water travels along the second supply line 32. In particular, the side line 32 circulates itself. Thus, the heating water receives heat, reaches the convection heater 7 to heat at least one environment in the building, and returns to be heated again.

[0059] This invention achieves significant advantages.

[0060] Firstly, it is possible to obtain remarkable heating performance that is fully compatible with the heating performance required for heating at least a portion of the building and heating sanitary water. Furthermore, maintenance becomes easier.

[0061] Furthermore, a compact and noise-free solution can be obtained.

[0062] The present invention can accept many modifications and variations, as can be imagined, all of which fall within the scope of the concept of the invention characterized thereby. Furthermore, all detailed components can be replaced with technically equivalent components. In practice, all materials used, as well as dimensions, may be whatever is necessary.

Claims

1. A system for heating water. A circuit (2) through which a working fluid circulates, including a heating means (20) for heating the working fluid, but not including an evaporator, A first supply line (31) for supplying sanitary water, A second supply line (32) for supplying water to heat at least one environment of the building, A first heat exchange means (5) performs heat exchange between the circuit (2) and the first supply line (31), The system comprises a second heat exchange means (4) that performs heat exchange between the circuit (2) and the second supply line (32), The heating means (20) consists of a piston pump (21), The system further includes a control unit for adjusting the temperature and pressure necessary to maintain the working fluid circulating within the circuit (2) in a liquid phase. A system characterized by the following features.

2. The system according to claim 1, comprising an electric motor (22) for driving the piston pump (21), wherein the electric motor (22) includes an asynchronous magnetoelectric motor (22) or is an asynchronous magnetoelectric motor (22).

3. The system according to claim 1, characterized in that the working fluid is R1233ZD(E).

4. The first heat exchange means (5) A closed path (50) through which the heat transfer fluid circulates, A first heat exchanger (52) that thermally connects the working fluid circulating in the circuit (2) and the heat transfer fluid circulating in the path (50), A heat exchange tank (53) is thermally connected to the first supply line (31), The system according to claim 1, characterized by including

5. The system according to claim 4, characterized in that the first supply line (31) of the sanitary water includes a coil (311) that passes through the inside of the heat exchange tank (53).

6. The system according to claim 5, further comprising an additional heat exchanger (54) for heat exchange between the circuit (2) and the first supply line (31).

7. The system according to claim 6, characterized in that it includes a throttle valve (23) inserted between the first heat exchanger (52) and the additional heat exchanger (54).

8. A method for heating water, comprising the system described in claim 1, The working fluid is circulated within circuit (2), The working fluid circulating through the circuit (2) is heated, Heat is transferred from the working fluid to the sanitary water, and the sanitary water moves along the first supply line (31). Heat is transferred from the working fluid to water for heating at least one environment in the building, and the water for heating moves along a second supply line (32). A method that includes the act of doing so.

9. The method according to claim 8, characterized in that the working fluid is R1233ZD(E).

10. The method according to claim 9, characterized in that the working fluid has a pressure of 6 to 8 bar.

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