DE102022119100A1 - Device for providing thermal energy to a heat sink - Google Patents

Abstract

A device 2 for providing thermal energy to a heat sink has an internal combustion engine 4 and an electric machine 6. The internal combustion engine 4 and the electric machine 6 are operatively connected to one another in a first operating mode in the manner of a combined heat and power plant, with the internal combustion engine 4 acting as a motor and the electric machine 6 acting as a generator. The invention provides a device 2 which can be operated as a hybrid unit between a combined heat and power plant and a heat pump either as a combined heat and power plant or as a heat pump.

Description

The invention relates to a device of the type mentioned in the preamble of claim 1 for providing thermal energy to a heat sink.

Such devices are well known and have an internal combustion engine and an electric machine, which are operatively connected to one another in the manner of a combined heat and power plant, in that the internal combustion engine acts as a motor and the electric machine acts as a generator. Corresponding combined heat and power plants generate electricity via the electric machine, while heat from the exhaust gas of the internal combustion engine is used to heat water in a heating system.

The invention is based on the object of specifying a device of the type mentioned in the preamble of claim 1 for providing thermal energy to a heat sink, which is improved compared to the known devices.

This object is achieved by the invention specified in claim 1.

Advantageous and useful developments of the invention are specified in the subclaims.

The invention provides that the device can be switched from the first operating mode to a second operating mode, in which the electric machine acts as a motor and drive for the internal combustion engine and the internal combustion engine acts as a compressor, such that a refrigerant is heated by compression in a working space of the internal combustion engine becomes. According to the invention, the working space of the internal combustion engine is in flow connection with at least one first heat exchanger for releasing thermal energy of the refrigerant to a heat sink. In the direction of flow of the refrigerant, an expansion valve and at least one second heat exchanger for heating the refrigerant are arranged downstream of the first heat exchanger, an outlet of the second heat exchanger being in flow connection with the working space of the internal combustion engine for introducing the refrigerant heated in the second heat exchanger into the working space of the internal combustion engine.

The invention is based on the knowledge that the units of a combined heat and power plant, namely an electric machine and an internal combustion engine, can be used as components of a heat pump when their functional principle is reversed. While in a combined heat and power plant the electric machine is used as a generator to generate electricity, in a heat pump the electric machine is used to drive a compressor. Based on this, the invention is based on the further finding that the internal combustion engine used in a combined heat and power plant can also be used as a compressor, reversing its functional principle, which is used in a heat pump to compress and heat a refrigerant.

The invention is based on the idea of operating the internal combustion engine as a compressor in a second operating mode and successively arranging a first heat exchanger, an expansion valve and a second heat exchanger in the flow direction of the refrigerant. The internal combustion engine is therefore used to compress the refrigerant, whereby the refrigerant is highly compressed and heats up. The compressed refrigerant is passed through the first heat exchanger and releases part of the heat as useful heat, for example to a heating system.

The cooled refrigerant is passed through the expansion valve (relief valve), which reduces the pressure and temperature of the refrigerant. The cooled refrigerant is then able to absorb ambient heat via the second heat exchanger, as is known from the functional principle of a heat pump.

The coolant heated by the ambient heat is then fed back to the internal combustion engine.

The invention thus provides a device that can be used as a combined heat and power plant in its first operating mode, while it can be used as a heat pump in its second operating mode.

In the first operating mode (combined heat and power plant mode), the internal combustion engine is operated as a motor, the waste heat of which can be used to provide thermal energy to a heat sink, for example a heating system, while the electric machine operated as a generator generates electricity.

In contrast, in the second operating mode (heat pump mode), the electric machine is used as a motor to drive the internal combustion engine used as a compressor.

The invention thus provides a hybrid solution between a combined heat and power plant and a heat pump, which can be operated according to the respective circumstances and requirements.

The invention is explained in more detail below with reference to the attached, block diagram-like drawing using an exemplary embodiment. It is obvious to the person skilled in the art that the individual features of an exemplary embodiment develop the exemplary embodiment individually, i.e. independently of the other features, so that it is apparent to the person skilled in the art that all of the features described, shown in the drawing and claimed in the patent claims Features taken on their own and in any technically sensible combination with one another form the subject of the invention, regardless of their summary in the patent claims and their references as well as regardless of their specific description or representation in the drawing. The subject matter and disclosure content of the present application also includes subcombinations of the patent claims in which at least one feature of a patent claim is omitted or replaced by another feature.

• 1 blockschaltbildartig ein Ausführungsbeispiel einer erfindungsgemäßen Einrichtung in einem ersten Betriebsmodus und
• 2 in gleicher Darstellung wie 1 das Ausführungsbeispiel gemäß 1 in einem zweiten Betriebsmodus.

It shows:

• 1 An exemplary embodiment of a device according to the invention in a first operating mode and
• 2 in the same representation as 1 the exemplary embodiment according to 1 in a second operating mode.

In 1 illustrates in block diagram form the functionality of an exemplary embodiment of a device 2 according to the invention for providing thermal energy to a heat sink in a first operating mode (combined heat and power plant mode). The device 2 has an internal combustion engine (combustion engine) 4, which in the exemplary embodiment shown is designed as a reciprocating piston engine. The internal combustion engine 4 is in operative connection with an electric machine 6. When the device 2 is in operation, the internal combustion engine 4 is operated as a motor and fed with fuel. The internal combustion engine 4, as a motor, drives the electric machine 6, which is operated as a generator and generates electricity. Heat released by the internal combustion engine 4 during operation is supplied to an exhaust gas heat exchanger 8 and released from this to a heat sink, for example a heating system.

2 illustrates the functionality of the device 2 according to the invention in a second operating mode in the form of a block diagram.

According to the invention, the device 2 can be switched from the first operating mode to the second operating mode (heat pump mode), in which the electric machine 6 is used as a motor and drive for the internal combustion engine 4 and the internal combustion engine acts as a compressor, such that in a working space of the internal combustion engine 4 a refrigerant, which in the illustrated embodiment is formed by air, is heated by compression,

The working space of the internal combustion engine 4 is in fluid communication with at least one first heat exchanger 10 for delivering thermal energy of the refrigerant to a heat sink, for example a heating system.

In the direction of flow of the refrigerant, which is in 2 is symbolized by an arrow 12, an expansion valve 14 and a second heat exchanger 16 are arranged downstream of the first heat exchanger 10 for heating the refrigerant by means of the ambient heat, with an outlet of the second heat exchanger 16 being in fluid communication with the working space of the internal combustion engine to initiate the in the second Heat exchanger 16 heated refrigerant into the working space of the internal combustion engine 4.

In the heat pump mode, the internal combustion engine 4, driven by the electric machine 6, is used to compress the refrigerant. During compression, the refrigerant is strongly compressed and heats up during this process. The compressed refrigerant is passed through the first heat exchanger 10 and releases part of the heat as useful heat, for example to a heating system. The cooled refrigerant is passed through the expansion valve 14, reducing the pressure and temperature. The cooled refrigerant is able to absorb ambient heat in the second heat exchanger 16. The coolant heated by the ambient heat is then introduced into the working space of the internal combustion engine 4.

$${\text{T}}_4<\text{Umgebungsw}\ddot{\text{a}}\text{rme}$$

$${\text{T}}_1<{\text{T}}_2$$

$${\text{T}}_3<{\text{T}}_2$$

The following applies to the pressure and temperature conditions of the refrigerant in the facility: $${\text{<figure-callout id="2" label="P" filenames="DE102022119100A1\_0005.png" state="{{state}}">P</figure-callout>}}_2>{\text{P}}_1$$

$${\text{<figure-callout id="4" label="T" filenames="DE102022119100A1\_0005.png" state="{{state}}">T</figure-callout>}}_4<\text{Ambient w}\ddot{\text{a}}\text{rme}$$

$${\text{T}}_1<{\text{<figure-callout id="2" label="T" filenames="DE102022119100A1\_0005.png" state="{{state}}">T</figure-callout>}}_2$$

$${\text{T}}_3<{\text{<figure-callout id="2" label="T" filenames="DE102022119100A1\_0005.png" state="{{state}}">T</figure-callout>}}_2$$

The invention thus provides a device that can be operated both as a combined heat and power plant and as a heat pump, so that a hybrid solution between a combined heat and power plant and a heat pump is provided through clever use of the units of a combined heat and power plant

Claims (3)

Device (2) for providing thermal energy to a heat sink, with an internal combustion engine (4) and with an electric machine (6), the internal combustion engine (4) and the electric machine (6) being operatively connected to one another in a first operating mode in the manner of a combined heat and power plant , wherein the internal combustion engine (4) acts as a motor and the electric machine (6) acts as a generator, characterized in that the device (2) can be switched from the first operating mode to a second operating mode in which the electric machine (6) acts as a motor and drive for the internal combustion engine (4) and the internal combustion engine (4) acts as a compressor, such that a refrigerant is heated by compression in a working space of the internal combustion engine (4), such that the working space of the internal combustion engine (4) is in flow connection with at least one first heat exchanger ( 10) is intended to deliver thermal energy of the refrigerant to a heat sink and that an expansion valve (14) and at least one second heat exchanger (16) are arranged downstream of the first heat exchanger (10) in the direction of flow of the refrigerant for heating the refrigerant, with an outlet of the second heat exchanger (16) is in flow communication with the working space of the internal combustion engine (4) for introducing the coolant heated in the second heat exchanger (16) into the working space of the internal combustion engine (4). Setup after Claim 1 , characterized in that the internal combustion engine (4) is a reciprocating piston engine. Setup after Claim 1 or 2 , characterized in that the refrigerant is air.

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