FR2484540A1 - HEATING SYSTEM COMPRISING A HEAT PUMP - Google Patents

Abstract

IN THIS INSTALLATION, THE CONNECTION PIPES BETWEEN THE HEAT EXCHANGER 28, WHICH RECOPS THE LOST HEAT FROM THE EXHAUST GASES OF THE ENGINE 12 OF THE COMPRESSOR 10 OF THE HEAT PUMP AND THE CENTRAL HEATING CIRCUIT 24, IS REMOVED. FROM CIRCUIT 24, THEN HEATED BY CONDENSER 20 OF THE HEAT PUMP, IS SENT INTO ENGINE COOLING CIRCUIT 12 AND EXCHANGER 28 IS MOUNTED IN A HOUSING WHICH IS ONE PIECE WITH THE ENGINE CYLINDER HEAD 12 AND THAT COMMUNICATES WITH THE COOLING WATER CIRCULATION DUCTS IN THE CYLINDER HEAD.

Description

The present invention relates to an installation

  heating with a heat pump, the

compressor is driven by an internal combustion engine

dull, the heat lost from the engine being transmitted via at least one heat exchanger to the heat transfer fluid circulating in the heating network of the installation, In known installations, of this type, the heat exchanger of

  heat is arranged as a separate and separate element

  dependent and it is connected by free lines to the heating network and to the motor housing on which it recovers waste heat. Since the installations of

  heaters are frequently turned on and off

Tomatically several times an hour, it is necessary to insert known expansion compensating joints (for example corrugated elastic tubes), in particular in

  the part of the pipe, located between the combustion engine

  internal tion and the exchanger, to allow expansion

  and multiple thermal contractions occur alternati-

in the pipeline network. Furthermore, it is necessary to provide a large number of connections in the lines which connect the internal combustion engine to the

heating circuit.

These installations therefore present serious

come. First, the acquisition of compensating joints

  dilators are expensive and their useful life is limited. In addition, great care must be taken to seal the many connections to prevent them from

fluids that might otherwise leak from the heating system

  fage or the engine does not dirty the premises, frequently the cellar of the houses. Finally, the maintenance and cleaning of the heat exchanger itself is very laborious and expensive because, for these operations, it is necessary to remove

  then connect many pipes.

  The object of the invention is to eliminate these drawbacks

  According to the known installations. According to the invention, this problem is solved by the fact that the part of the casing

of the internal combustion engine on which the heat per-

due is recovered is suitably shaped to serve at the same time as housing for the heat exchanger. This configuration according to the invention makes it possible to build a heating installation which requires only the minimum of free lines between the heating circuit and the internal combustion engine. The waste heat which is present on a part of the engine casing is transmitted almost completely to the heat exchanger housed in this same part of the casing, so that a high heat exchange efficiency is obtained. Furthermore, there is no need to provide any free connection or expansion compensating joint between the motor and the heat exchanger so that an economical construction and favorable operation are obtained.

to the environment.

In heating systems, the heat from

exhaust from the internal combustion engine is frequently

used as waste heat, recovered and transmitted via the heat exchanger to the heat transfer fluid in the heating circuit. In this case, and according to another advantageous characteristic of the invention, the

engine cylinder head, which has the exhaust gas pipe

ment, and the exchanger housing are made under the

  form of a single part of the body of the engine of ma-

  means that the engine exhaust passes directly-

  ment from the exhaust duct to the exchanger mounted in the

same part and only leave the breech after having

ran this exchanger.

This characteristic of the invention can be implemented in a simple manner when there is provided in the cylinder head of the internal combustion engine at least one duct which surrounds the heat exchanger and in which the heat transfer fluid is sent at its outlet. of the heating circuit and where it licks the exchanger traversed by the exhaust gases. This embodiment can be used regardless of the nature of the fluid used as the heat transfer fluid in the heating circuit and

also regardless of the type of combustion engine

  internal tion used for training. In this case, it is therefore possible to use a combustion engine as well

  internal air-cooled.

  The invention can be implemented in another form, which is particularly advantageous, in installations using water as heat transfer fluid and in the case of

engines. water-cooled internal combustion.

In such a case, there must be provided in the cylinder head of the engine at least one conduit which surrounds the heat exchanger and in which the water circulates and where it licks the heat exchanger.

heat, the heated water is sent to the heating circuit

  fage after licking the heat exchanger.

  Another judicious improvement of the invention, which is of a constructive nature, is that the heat exchanger constitutes a unit in one piece and is mounted in the housing provided inside the cylinder head of the combustion engine. internal so that it can be dismantled and replaced from the outside. In this improved embodiment, the disassembly and reassembly of the heat exchanger which may be necessary for the

cleaning and maintenance can be performed very easy-

is lying.

  Other characteristics of the invention appear

tront during the description which follows. To the-

  attached sins, given only a. example title:

Fig. 1 schematically represents a pump.

  heat with its compressor and combustion engine

dull that causes it;

Fig.2 is a partly sectional view along

  vertical cylinder and engine cylinder head; Fig.3 is a horizontal section of the cylinder head along line A-A of Fig.2; Fig, 4 is a vertical sectional view of the

cylinder head, along line B-B in Fig. 3.

  The heat pump shown diagrammatically in FIG. 1 includes a compressor 10 with two cylinders used to compress the refrigerant in its circuit, the input shaft 10a of the compressor 10 being driven by the output shaft, it is ie by the crankshaft 12a of a water-cooled internal combustion engine 12, of a type of construction known, for example, by a single-cylinder internal combustion engine with injection. In an evaporator 14

placed upstream of the compressor 10, the refrigerant li-

  quide, whose temperature is then about 2 C evaporates.

  rise and, in this transformation, absorb heat from the environment which surrounds it, for example, from ground water or

air, as indicated by arrow E. The vapor from the fluid

  of refrigerant is then sent to compressor 10 by

  a suction line 16. During the compression phase

  sion, the refrigerant vapor is compressed and heated to then be sent to a condenser 20 by u a line 18. The refrigerant vapor, which has been brought to about 60 C in the compressor, passes through the condenser 20 by circulating in a duct 20a, then gives up most of its heat and reliquifies4 The

  condensed and cooled refrigerant goes through an expansion

  26, relaxes and returns to its initial temperature

  about 2C. It then returns to evaporator 14 to

start a new circuit in the heat pump.

The spent and cooled heating water coming from a heating installation, for example from a central residential heating circuit 24, passes through the condenser in a separate pipe 22 and absorbs the transferred heat.

  by the refrigerant. After crossing the conden-

The heating water is sent to a 12b pre-

  seen on the internal combustion engine 12 through which it is introduced into the cooling circuit of this engine, indicated in phantom, to ensure the cooling of the engine. At the end of this cooling circuit, It

  the heated water passes through a top heat exchanger

28 and is further heated by the waste heat supplied by the engine exhaust. The strongly heated water is then sent to another connection 12c of the engine 12 by which it leaves the cooling circuit. The strongly heated water is sent through a pipe 30 to the heating circuit 24 which transfers most of the heat contained in the water to the

  heating needs of the home, in the indi-

qué by arrow H. The details of the engine 12 cooling circuit, which is simply shown schematically on the

Fig.l, and of the additional heat exchanger 28

  emerge from the description given below as well as from the

very figures. The arrangement of the cylinders and the cylinder head

  of the motor 12 is shown in section. The cylinder 32 re-

  receives a jacket 34 arranged vertically, in which a piston 36 is guided. The connecting rod 38 coupled to the piston

  attacks the crankshaft 12a of the engine 12 in a known manner.

To the cylinder 32 is fixed, by means of four screws 40, a cylinder head 42 in which an intake valve 44, an exhaust valve 46 and a fuel injector

  48 are mounted in a known manner. Each valve is activated

operated by a corresponding rocker arm 50 which is controlled

  by a distribution mechanism not represented by the inter-

  in the middle of a pusher, in a manner also known.

teurs 54 contains the two rocker arms 50 oour isolate them from the outside. Combustion air is supplied to the valve

intake 44 through a duct 42a while the exhaust gases

which exit through the exhaust valve 46 are evacuated.

capped by the exhaust duct 42b.

  The operating mode of an internal combustion engine with injection. four stroke of the kind described is known

  and therefore it is not necessary to explain it in detail.

Between the elements 32 and 34 is formed a narrow annular space 56 which communicates for the circulation of the fluid with the abovementioned water connection 12a, which is arranged in the lower region of the elements 32, 34. Two transverse holes 58 represent the communication between the annular space 56 and two holes 60 each of which is formed in a lateral flange 32f of the element 32. For

cool the cylinder 32,34 and the cu-

  weary 42, the water penetrates from bottom to top into the spaces 56, and it passes through two passage openings 42d of the cylinder head 42, in the cooling conduits 42k formed

inside the cylinder head 42.

The cylinder head 42 is suitably shaped to serve at the same time as a support for the heat exchanger 28. A

  duct 42t which extends perpendicular to the axis of the cy-

lindre and extends in the horizontal direction is limited by the tubular walls 42w of the cylinder head 42 and is joined to the cylinder head 42 by intermediate walls 42z to form with the cylinder head a one-piece assembly. A connecting duct

42v is formed between the walls 42w and 42z and extends parallel

  in line with duct 42t. The 42v conduit is in communication

  for circulation of the fluid with the cooling duct

  42k through a passage 42s which has the shape of a conduit and extends below the conduit

  42b, so that water can flow from the

  cooling baking formed inside the cylinder head 42 in the connecting duct 42v and, from there, through the orifice 42vv

in the annular duct 42t.

The tubular wall 42w of the cylinder head 42 forms at its two ends tubular bearing flanges 42f in which the heat exchanger 28 is housed. This exchanger is composed of a large number of small thin tubes 28a which are held together at their ends in two retaining plates 28b. In this way, the heat exchanger 28 can be introduced in the form of a single unit in the flanges of bearing 42f passing

  through a lateral opening 42o made in the cylinder head-

se 42 and which can be closed by a cover 62. The con-

  exhaust dub 42b of the cylinder head 42, on the contrary, opens into a chamber 42bb formed between the bearing flange 42f and the cover 62 so that the hot exhaust gases which exit through the exhaust valve 46 pass from the chamber 42bb in the lumen of the small thin tubes 28a of the exchanger and come out on the other side to be sent,

by an exhaust duct 64, to. an exit point ap-

  property. By traversing the heat exchanger 28, that is to say the small tubes 28a of this exchanger, the exhaust gases which exit from the cylinder with a temperature of approximately 400 ° C. yield to the water which surrounds the small tubes 28a a large part of their heat which is constituted by the waste heat released during the combustion process, so that, in the outlet pipe 64, the exhaust gases do not

have more than a temperature of around 150'C, The water forms

  tally heated by the exhaust gases leaves the duct 42t through an opening 42tt and is led by the connection pipe 12c, to the heating circuit -24 in which

  it gives up its heat to heat the home

tion in a known manner.

  The advantages which result from the configuration given to. the cylinder head 42 so that it serves at the same time as housing for the heat exchanger 28 have already been described

  in detail at the start. It will therefore suffice to add that, unlike

reference of the example of embodiment described, a common casing

for the cylinder head and the heat exchanger would still be used

  sand if the heat transfer fluid from the heating system

and the engine coolant to. inter combustion

  were not of the same nature (water). Furthermore, the additional heat exchanger 28 could similarly be integrated into a single unit with an element of the engine body other than the cylinder head, if it seemed indicated, in certain engines, to take the waste heat in another.

  place only in the breech and give it in this other

right in the additional heat exchanger. For example, we could consider making the housing

engine crankshaft at the same time in the form of a lo-

  heat exchanger element if the waste heat from the hot lubricating oil collected in this crankcase should be transmitted via the heat exchanger

  the heating water or another agent circulating in the ins

heating plant.

Claims (6)

1 - Heating installation comprising a heat pump, the compressor of which is driven by an internal combustion engine, and in which the waste heat from the internal combustion engine is transmitted to the heat transfer fluid circulating in the heating circuit by   through at least one heat exchanger, charac- characterized in that the part (42) of the body of the internal combustion engine (12) in which the waste heat is recovered is produced with a configuration such that it serves at the same time as housing for the exchanger heat (28).   2 Heating installation as sold cation 1, comprising an internal combustion engine whose waste heat is transmitted to the heat transfer fluid circulating in the heating circuit via of the heat exchanger, characterized in that the cylinder head-   se (42) of the engine (12> which includes the exhaust gas duct, and the housing (42f) - receiving the heat exchanger (28) are made in one piece of the engine body, so that the engine exhaust gases are directly led to the heat exchanger mounted in the same part of the engine body and do not leave   the cylinder head only after having traversed the heat exchanger.   3 - Heating installation according to the claim tion 2, characterized in that it is provided in the culas-   se (42) of the internal combustion engine (12) at least one conduit (42t) which surrounds the heat exchanger (28), in which the heat transfer fluid circulates leaving the heating network (24) and o this fluid licks the exchanger of heat traversed by the exhaust gases. 4 - Heating installation according to the claim   tion 2, in which water is used as heat transfer fluid in the heating circuit and which comprises an internal combustion engine with water cooling, characterized in that it is provided in the cylinder head (42) of the combustion engine internal (12) at least one conduit (42t) which surrounds the heat exchanger (28) and in which the water circulates and where this water licks the heat exchanger traversed in the exhaust gases, the heated water being sent to the heating circuit (24) after licking the heat exchanger. 5. Heating installation according to the claim tion 2, characterized in that the heat exchanger (28) is designed as a unit in one piece and is arranged in the housing (42f) of the cylinder head (42) of the internal combustion engine (12), so that it can be   dismantled and replaced from the outside.   6 - Heating installation according to the claim tion 6, comprising a heat exchanger composed of a large number of parallel tubes, open at their ends   tees and assembled at these ends in circular supports rings, characterized in that, for each support (.28b), it is provided in the housing (42f) formed in the cylinder head (42) of the internal combustion engine (12) a hole in the door   tee in which the support is supported by a tight seal. ê