U.S. patent application number 14/206037 was filed with the patent office on 2014-09-18 for combined heat and power (chp) system.
This patent application is currently assigned to Dejatech GES B.V.. The applicant listed for this patent is Dejatech GES B.V.. Invention is credited to Jan Hubertus DECKERS, Paulus Mathijs Maria THIJSSEN.
Application Number | 20140260218 14/206037 |
Document ID | / |
Family ID | 48577816 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140260218 |
Kind Code |
A1 |
DECKERS; Jan Hubertus ; et
al. |
September 18, 2014 |
COMBINED HEAT AND POWER (CHP) SYSTEM
Abstract
Combined Heat and Power (CHP) system, comprising an engine or
turbine, a generator and a heat exchanger, wherein the heat
exchanger has at least one flue duct in fluid communication with an
exhaust of the engine or turbine and at least one fluid duct, the
heat exchanger arranged for exchange of heat between flue gasses
flowing through the at least one flue duct and a fluid flowing
through said at least one fluid duct, wherein the at least one flue
duct is formed by at least extrusion.
Inventors: |
DECKERS; Jan Hubertus;
(Belfeld, NL) ; THIJSSEN; Paulus Mathijs Maria;
(Belfeld, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dejatech GES B.V. |
Belfeld |
|
NL |
|
|
Assignee: |
Dejatech GES B.V.
Belfeld
NL
|
Family ID: |
48577816 |
Appl. No.: |
14/206037 |
Filed: |
March 12, 2014 |
Current U.S.
Class: |
60/320 |
Current CPC
Class: |
F01K 5/02 20130101; F28F
21/084 20130101; F01K 23/10 20130101; Y02E 20/16 20130101; F01N
5/02 20130101; F28D 9/0081 20130101; F28F 2255/16 20130101; F28F
2275/025 20130101; F28F 3/048 20130101; F28D 21/001 20130101; Y02E
20/14 20130101; F05D 2220/64 20130101; F02C 6/18 20130101 |
Class at
Publication: |
60/320 |
International
Class: |
F01N 5/02 20060101
F01N005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 12, 2013 |
NL |
2010441 |
Claims
1. Combined Heat and Power (CHP) system, comprising an engine or
turbine, a generator and a heat exchanger, wherein the heat
exchanger has at least one flue duct in fluid communication with an
exhaust of the engine or turbine and at least one fluid duct, the
heat exchanger arranged for exchange of heat between flue gasses
flowing through the at least one flue duct and a fluid flowing
through said at least one fluid duct, wherein the at least one flue
duct is formed by at least extrusion.
2. CHP system according to claim 1, wherein the heat exchanger is
made using extrusion technology and wherein at least the flue duct
or ducts and the water duct or ducts are made in light metal,
especially aluminium or an aluminium blend.
3. CHP system according to claim 1, wherein the flue duct is
defined by flue duct defining walls which have a surface roughness
of less than about 25 Ra, preferably less than 12.5 Ra, more
preferably less than 6 Ra, even more preferably less than 2 Ra.
4. CHP system according to claim 3, wherein the roughness is less
than 1 Ra, preferably about 0.8 Ra or less.
5. CHP system according to claim 1, wherein the at least one flue
duct has flue duct defining walls which are, seen in a flow
direction of the duct, free of obstructions such as heat exchanging
surface increasing elements.
6. CHP system according to claim 1, wherein the at least one flue
duct comprises a series of parallel duct sections, fluidly
connected to each other for forming a zig-zag flue path, wherein
each of the sections, seen in a flow direction of gas through the
relevant section, is free of obstructions such as heat exchanging
surface increasing elements.
7. CHP system according to claim 1, wherein the at least one flue
duct is straight or has parallel sections which are straight,
wherein a flow direction of gas through said at least one flue duct
or said parallel sections thereof is parallel to a extrusion
direction of said duct or duct section.
8. CHP system according to claim 1, wherein the heat exchanger is
provided with at least one closable opening into said at least one
flue duct, for cleaning of the flue duct.
9. CHP system according to claim 1, wherein the heat exchanger
comprises a body made by extrusion, including said at least one
flue duct and said at least one fluid duct, and wherein opposite
ends of the body are closed by end elements, which are preferably
glued to the body.
10. CHP system according to claim 1, wherein the heat exchanger
comprises at least two parts made at least partly by extrusion from
light metal or light metal alloy, said at least two parts mutually
engaging for forming part of a heat exchanging space formed by or
comprising said at least one flue duct and/or a water conducting
channel formed by or comprising said at least one fluid duct,
wherein each of said at least two parts comprises part of said heat
exchanging space and/or said water conducting channel, wherein said
at least two parts are connected by an elastic bonding agent, in
particular an elastic glue, forming a bond and a seal.
11. CHP system according to claim 1, wherein the CHP further
comprises a cooling circuit for the engine or turbine, which
circuit includes a second heat exchanger, which has a fluid duct
connected in or to a fluid circuit including the at least one fluid
duct of the first heat exchanger, such that during use heat can be
transferred from the cooling fluid of the engine to the fluid
flowing through the circuit including the said fluid duct of the
first heat exchanger.
12. CHP system according to claim 1, wherein the at least one flue
duct or parallel sections of the flue duct(s) has/have straight
duct forming walls and substantially rectangular cross sections
perpendicular to a direction of flow through said duct or
section.
13. CHP system according to claim 1, wherein the flue duct or
parallel sections of the flue duct extend in a direction of
extrusion of the heat exchanger, and are free from flow
obstructions and heat exchanging surface increasing elements
extending into the duct or section as such obstruction.
14. CHP system according to claim 1, wherein the heat exchanger is
positioned such that the flow of flue gas through the heat
exchanger is substantially horizontally.
15. CHP system according to claim 1, wherein the system further
comprises at least one of: at least one and preferably at least two
containers for holding water heated by the said heat exchanger or
heat exchangers; at least one heating circuit for special heating;
at least one additional heating boiler for heating fluid,
especially water; and a controller for at least the engine or
turbine, the generator and a pump in a fluid circuit connected to
the at least one fluid duct.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.119
to Application NL 2010441, filed Mar. 12, 2013, which is hereby
incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a combined heat and power (CHP)
system. Such systems are known in the art and combine an engine or
turbine with a generator for generator electricity and with a heat
exchanger for generating heated fluid, especially water for for
example industrial or household use. Such water can for example be
used for space heating, for tap water or for generating industrial
heat for use in for example industrial processes.
BACKGROUND OF THE INVENTION
[0003] CHP systems are known comprising a heat exchanger made by
casting or moulding from for example light metal, such as aluminium
or aluminium alloy, such as for example disclosed in EP1752647,
which has a standard heat exchanger of a central heating system
integrated with a Stirling motor. The heat exchanger is cast from
aluminium and has a gas flow duct filled with heat exchanging
surface increasing elements. The heat exchanger is arranged such
that the main flow direction of the gasses through the gas flow
duct is mainly vertical. Exhaust gas from the Stirling motor is fed
up through a hollow core of the heat exchanger and then out into
the gas duct, to be taken along down through the gas duct and out
through an exhaust.
[0004] In alternative CHP systems a standard, monoblock aluminium
cast heat exchanger is used, such as for example an Alutop.RTM.
heat exchanger, offered by Bekaert BvbA, Belgium, which is lied in
a horizontal position. An exhaust pipe of a motor or turbine of the
CHP is connected to the inlet space of the heat exchanger, such
that flue gasses from the motor or turbine flow substantially
horizontally through the flue gas duct of the heat exchanger,
exchanging heat with water flowing through the water duct of the
heat exchanger.
[0005] In these CHP systems problems occur with the heat exchangers
due to contamination carried in the exhaust gas from the turbine or
engine. These contaminations can be solid particles, such as soot,
but can also be fluid, such as oil. Such contamination does get
stuck inside the heat exchanger, especially in the flue duct or
ducts, resulting in for example reduced efficiency of the heat
exchanger, increased exhaust of small particles by the exhaust and
contamination of for example filters and catalysts. These known
heat exchangers cannot be cleaned properly, which means that the
heat exchangers have to be replaced relatively regularly, which is
costly and time consuming. Moreover, this reduces the environmental
advantages that are strived for by a CHP.
[0006] U.S. Pat. No. 5,473,884 discloses a CHP system in which gas
from a small gas turbine is fed passed a gas burner into a gas
channel and through two series of parallel pipes extending through
a tank of water for exchanging heat. These pipes will be made of
stainless steel and extend substantially horizontally. Due to the
straight pipes made of stainless steel, contamination by small
particles and for example oil may be less of a problem then in cast
aluminium heat exchangers, but such heat exchanger does not allow
for cleaning in an easy manner either, without having to dismantle
most of the heat exchanger. Moreover, such CHP and especially the
construction of the heat exchanger is very costly due to inter alia
the metal used, and the necessity of welding all pipes and other
parts together, water and gas tight.
SUMMARY OF THE INVENTION
[0007] The present disclosure aims at an alternative CHP system.
The present disclosure also aims at a CHP system which avoids or
mitigates at least one or some of the problems of the known CHP
systems as discussed in the introduction to this specification here
above. The present disclosure furthermore or alternatively aims at
a CHP system which is highly reliable and efficient, easy to
maintain and/or less prone to contamination than the systems
according to the prior art.
[0008] At least one of the aims and other advantages can be
obtained with an CHP system according to this disclosure.
[0009] In a first aspect an CHP system of the present invention can
be characterized in that it comprising an engine or turbine, a
generator and a heat exchanger, wherein the heat exchanger has at
least one flue duct in fluid communication with an exhaust of the
engine or turbine and at least one fluid duct. The heat exchanger
is arranged for exchange of heat between flue gasses flowing
through the at least one flue duct and a fluid flowing through said
at least one fluid duct. According to this aspect of the disclosure
the at least one flue duct is formed by at least extrusion.
[0010] In preferred embodiments the heat exchanger of the CHP has a
heat exchanger body comprising said at least one flue duct or at
least the major part thereof, and preferably also the said at least
one fluid duct, or again at least the major part thereof, wherein
the body is made substantially by extrusion and/or by assembling
parts made by extrusion, wherein the said at least one flue duct
has a main direction of flow parallel to the extrusion direction of
the body or the extruded parts thereof.
[0011] In a further aspect the heat exchanger can be made using
light metal or light metal alloy, such as aluminium or aluminium
alloy. Light metal is considered to be non-ferro metal having a
density of less than about 4500 kg/m.sup.3. Preferred metal is
aluminium or aluminium alloy in a extrusionable grade.
[0012] In another aspect the heat exchanger of the CHP can comprise
a body and end elements, wherein the body comprises a series of
flue duct sections, extending parallel to each other and connected
at, in and/or near the end elements, for example by removing part
of a wall between such sections and/or by duct parts formed in or
by the end elements. Preferably similarly the or each water duct is
in part formed in the body, by a series of parallel duct sections,
connected in, at or near the end elements. The body can be made
from one extruded element or by a series of interconnected extruded
elements.
[0013] In another aspect a heat exchanger of the CHP can be made
such that the at least one the flue duct is defined by flue duct
defining walls which have a surface roughness of less than about 25
Ra, preferably less than 12.5 Ra, more preferably less than 6 Ra,
even more preferably less than 2 Ra. The roughness can be 1 Ra or
lower, for example 0.8 Ra or lower. By using extrusion for forming
said duct defining walls such surface roughness is obtainable
without the necessity of additional machining
[0014] In another aspect a heat exchanger of a CHP can be provided
with at least one closable opening into said at least one flue
duct, for cleaning of the flue duct.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present invention shall be further elucidated in the
following description, with reference to the drawings, in
which:
[0016] FIG. 1 shows in perspective view a CHP system, without
attached heating circuits;
[0017] FIG. 2 shows schematically a flow diagram of a CHP system
with connected thereto an additional heating boiler and heating
circuits;
[0018] FIG. 3 shows a heat exchanger, schematically, in perspective
view;
[0019] FIG. 4 shows in perspective view a part of a heat exchanger,
shown generally from a first side;
[0020] FIG. 5 shows in perspective view a part of a heat exchanger,
shown generally from an opposite side;
[0021] FIG. 6 shows a partly assembled heat exchanger from a first
end;
[0022] FIG. 7 shows a first part of a heat exchanger in a side
view;
[0023] FIG. 8 shows a second part of a heat exchanger in a side
view;
[0024] FIG. 9 shows in perspective view a partly assembled heat
exchanger from a second side;
[0025] FIG. 10 shows a heat exchanger of FIG. 9, with a mounted end
plate;
[0026] FIG. 11 shows a heat exchanger of FIGS. 9 and 10, from an
opposite end;
[0027] FIG. 12 shows schematically a gas flow path of a heat
exchanger according to the present disclosure;
[0028] FIG. 13 shows schematically a water flow path of a heat
exchanger according to the present disclosure;
[0029] FIG. 14 shows in perspective view schematically an enlarged
part of a heat exchanger part;
[0030] FIGS. 15A and B are frontal and side views, respectively, of
a part of a heat exchanger part, in further detail; and
[0031] FIGS. 16A and B are side views of connecting parts of a heat
exchanger part, in further detail.
DETAILED DESCRIPTION
[0032] In this description different embodiments of a CHP system
and parts thereof are disclosed and described. Moreover, in this
description different embodiments of heat exchangers and parts
thereof for such CHP systems, as well as heating circuits equipped
therewith are disclosed and described by way of example only. In
these embodiments the same or similar parts have the same or
similar reference signs. Combinations of parts of the embodiments
shown are also considered to have been disclosed herein. In this
description a heat exchanger as to be understood as an exchanger
for exchanging heat between heated flue gasses from an engine or
turbine and possibly additionally a burner and water flowing
through one or more water channels within said heat exchanger. Such
CHP systems are especially, but not exclusively suitable in
domestic and commercial heating systems such as for sanitary (tap)
water and central heating systems, such as for space heating and/or
tap water heating systems.
[0033] In the following description extrusion, possibly combined
with machining of extruded parts, shall be described as a means for
manufacturing parts of a heat exchanger for such CHP system.
Nevertheless, some or all of these parts can also be made by
casting, such as but not limited to injection moulding, sand or
otherwise lost core moulding or casting or the like, combined with
machining, such as but not limited to grinding, turning, milling,
drilling and the like known machining methods, in order to provide
a desired surface roughness and configuration of at least flue duct
or flue ducts in the heat exchanger.
[0034] It has been found that a major problem of heat exchangers of
CHP systems made by casting, even if made from aluminium or an
aluminium alloy is contamination. Surprisingly it has been found
that surface roughness of walls of the gas ducts of the heat
exchanger has a high impact on the contamination. Moreover, it has
been found that not, at least not only solid particles such as soot
is a major cause for contamination, but also oil originating from
the engine or turbine, transferred to the heat exchanger by the
exhaust gas. Contamination reduces the effectiveness of heat
transfer and moreover leads to contamination of the exhaust gasses,
for example by small particles. Moreover it reduces significantly
the economical and technical lifespan of the heat exchanger. In
stainless steel heat exchangers contamination has proven to be less
of a problem, although they are mostly difficult to clean, but such
heat exchangers are significantly more expensive. It has been found
that extrusion of the gas ducts of a heat exchanger for a CHP
system from light metal, such as aluminium or aluminium alloy,
provides for the advantage that very little oil or other liquids
will stick to the duct surfaces, whereas they can be made
relatively cheaply.
[0035] It has been found surprisingly advantageous when the surface
roughness of the said extruded ducts or at least walls hereof is
kept low, especially well below about 25 Ra, such as less than 12.5
Ra, more preferably less than 6 Ra, even more preferably less than
2 Ra. Preferably the surface roughness is less than 2 Ra, for
example about 1 or 0.8 Ra or less. This is relatively easily
achievable with extrusion of light metal, especially aluminium or
aluminium alloy, without the necessity of further machining for
reducing the surface roughness. Moreover it has been found that the
extrusion process has the advantage that the surface hardness of
the duct walls can be higher than when casting a similar heat
exchanger. This appears to be also beneficial to reduction of
contamination, even after a prolonged period of time of use.
[0036] The gas duct or gas ducts of the heat exchanger preferably
are free of obstructions such as heat exchanging surface increasing
elements, at least in the direction of flow of gas through said
duct or ducts or at least parallel sections thereof. Surprisingly
this will be beneficial to the heat exchanging characteristics of
the heat exchanger, even though the heat transferring surface area
compared to the overall volume of the heat exchanger is reduced and
thus it would be expected that the heat transfer would be
negatively influenced. Nevertheless a very highly efficient CHP has
been obtained by using a heat exchanger according to the present
disclosure, which moreover has a long economical and technical life
span.
[0037] A heat exchanger can for example be according to
WO2010/098666, wherein instead of a burner in a burner space the
burner space is redefined as an inlet space to which an exhaust gas
pipe coming from the engine or turbine is connected to said space
as an inlet for said exhaust gas.
[0038] FIG. 1 shows schematically a CHP unit 100 of a CHP system
101, in perspective view with a partly taken away cover 102. This
figure shows the unit 100 comprising an engine 104, for example a
gas, diesel, petrol, bio fuel or gasoline driven engine, a Stirling
type engine or any other suitable engine, such as a combustion
engine. Alternatively the CHP unit can comprise a turbine, for
example a gas turbine or other suitable type of turbine. The engine
104 or, alternatively, the turbine is coupled to a generator 105,
such that the generator 105 can be driven by the engine or turbine
for generating electricity.
[0039] The CHP unit 100 furthermore comprises a heat exchanger 1,
connected to a exhaust outlet 106 of the engine or turbine 104,
such that exhaust gasses from the engine or turbine 100 are fed
into a flue duct 6 of the heat exchanger 1, from which they can be
expelled through a gas outlet 107. A catalyst 108 can be included
in the exhaust outlet 106 for cleaning at least part of the flue
gasses, as is known from for example road car exhaust systems. A
muffler 109 can be provided in the gas outlet, for example for
providing back pressure and/or reducing noise.
[0040] As can especially be seen in FIG. 2 a water inlet and water
outlet 9A, 9B can be provided of a water duct 7 for feeding water
(or another fluidum to be heated) and exchanging heat with,
especially receiving heat from exhaust gasses flowing through the
flue duct or ducts 6.
[0041] FIG. 2 shows schematically a CHP system 101, comprising a
CHP unit 100, connected to at least a heating circuit 199. The
system 101 again comprises an engine or turbine 104, a generator
105 coupled thereto and a heat exchanger 1, coupled to the exhaust
side of the engine or turbine 104 by the exhaust outlet 106. In the
embodiment shown a turbine is shown, which can be a gas turbine
104. At least one flue duct 6 extends through the heat exchanger 1
from a gas inlet 33 to a gas outlet 34. A gas exhaust 107 with a
muffler 109 is connected to the gas outlet 34. The or each flue
duct 6 forms part of a gas side of the heat exchanger 1.
[0042] A heating circuitry 43 is connected to the or each water
duct 7 of the heat exchanger 1, forming part of a water side of
said heat exchanger 1. The water duct or ducts 7 have an outlet 9B
which is connected to a heating element, such as a spiral 110
provided in a first water container 111, such as a vat for central
heating water, by a first pipe 112. The element 110 is connected to
a second pipe 113 which is connected through a first pump 114 to a
first inlet 116 of a first flow side of a second heat exchanger
115, for example a plate heat exchanger or any other suitable type.
A first outlet 117 of the same first flow side of the second heat
exchanger 115 is connected, through a third pipe 118, to the inlet
side 9A of the water duct or ducts 6 of the first heat exchanger 1.
An overpressure release valve 118A can be provided in said
circuitry 43, especially in said pipe 118. Thus water can be pumped
through said circuitry 43, passing through the first and second
heat exchangers 1, 115 and the heating element 110. In the first
heat exchanger 1 during use heat can be transferred from hot
exhaust gasses of the engine or turbine 104 and water flowing
through the water duct or ducts 6.
[0043] A second flow side of the second heat exchanger 115 is
further connected to a cooling circuit 119 for the engine or
turbine 104, such that warm cooling fluid of the engine or turbine
104 can be fed through the second flow side of the second heat
exchanger 115 for transferring heat from the cooling fluid to water
flowing through the first flow side of said second heat exchanger
115. A short circuit line 120 can be provided in the cooling
circuit 119, such that cooling fluid can be fed directly back into
the cooling system of the engine or turbine 104, bypassing the
second heat exchanger 115, for example when the temperature of the
cooling fluid is below a pre set minimum value and/or the
temperature of the water in the first flow side of the second heat
exchanger is above a pre set value, or the temperature difference
between the two is below a pre set value. This can for example be
controlled by a thermostatic valve 121 provided in the circuit 119
or by other means. Thus, if desirable, water can be preheated by
the cooling fluid inside the second heat exchanger 115, before
being introduced into the water duct or ducts 6 of the first heat
exchanger 1.
[0044] Within the first container 111 heat can be exchanged from
the element 110 and water flowing there trough to water present
inside the container 111 surrounding the element 110. The first
container 111 comprises a first outlet 122 which is connected to an
inlet 127 of a central heating system 123, in FIG. 2 shown
schematically by a radiator 45. Obviously such heating system 123
can be designed differently, for example with more radiators,
convector elements, heat sinks or other heating means. Moreover
more than one such heating circuits can be coupled to the container
111. A return line 124 of the heating system 123 is coupled to a
first return inlet 125 of the first container 111. A short circuit
line 126 can be provided for feeding part of the return water
coming from the heating system 123 back into the inlet 127, without
passing back into the container 111. A mixing three-way valve 126A
can to that end be provided, for example temperature controlled or
controlled by a controller.
[0045] The first container 11 is further provided in this
embodiment with a second outlet 128, which feeds into a second
heating element 129, for example a second spiral inside a second
container 131, containing sanitary water 132. The second element
129 is connected to an outlet 133 feeding water back into the first
container, for reheating. A second pump 134 can be provided for
feeding water from the first container 111 through the second
heating element 129. A sanitary water inlet 144 and sanitary water
outlet 145 are provided for the second container 131, which can be
connected to a sanitary water system (not shown) Alternatively
these can be connected to an alternative heating system, for
example for industrial heating.
[0046] The first and second containers can be used in combination
or one or both can be omitted. A heating system 123 can for example
be fed directly from the first heat exchanger 1. Sanitary water
such as tap water can be heated differently, for example through a
direct heat exchanger heated by flue gasses or water fed from the
first heat exchanger.
[0047] In the embodiment shown as a further additional, optional
feature a heating boiler 135 is provided, for example a central
heating boiler as known in the art, which can for example be a gas
operated central heating boiler. The boiler can for example be
connected to the first pipe 112 through a three way valve 136 and
to the first heating element 110, such that water coming from the
first heat exchanger 111 is further heated by the heating boiler
135 before being fed into the heating element 110. This three way
valve 136 can for example be a thermo operated valve, changing over
when the water temperature in the first pipe 112 is below a pre set
value, for example below about 80.degree. C.
[0048] In use the engine or turbine is driven, driving the
generator for providing electrical energy or electricity.
Alternatively the engine or turbine could be used for driving
another piece of machinery. Hot exhaust gasses, for example of
between 500 and 600.degree. C., for example about 560.degree. C.
are fed into the gas side of the first heat exchanger, into and
through the or each flue duct 6. The exhaust gas is cooled down in
side the first heat exchanger 1 to for example a temperature of
below 100.degree. C., for example about 70.degree. C.
[0049] The heat from the exhaust gas is transferred to water pumped
through the water side of the first heat exchanger 1, especially
through the or each fluid duct 7. The water temperature will
thereby be increased, for example to a temperature between 60 and
90.degree. C. Preferably the temperature is raised to a temperature
above 80.degree. C. This heated water is then fed through the
heating circuitry 43, especially through the element 110 and the
second heat exchanger 115. In the second pipe 113 the water
temperature may have been reduced, for example to about 60.degree.
C. or less. In the second heat exchanger the water temperature can
then again be raised by heat absorption from the cooling fluid of
the motor, if fed through the second heat exchanger 115.
[0050] Thus an energy friendly and effective system is obtained for
generating both electricity and heat, wherein the heat can
effectively be used for heating purposed, industrially and/or
domestic.
[0051] Between for example the two heat exchangers 1, 115 a
pressure relief valve 118A can be provided. A third pump 141 can be
provided in the cooling circuit. A fourth pump 142 can be provided
in the heating system 123, for example at the outlet side
thereof.
[0052] A controller 143 can be provided for controlling the
operation of the unit 100 in general, and of various components of
the CPH system. For example the controller 143 can be designed for
controlling the engine or turbine 104, the generator 105, the
first, second, third and/or fourth pump, the optional boiler 135,
the valve 126A and/or the three way valve 136.
[0053] A heat exchanger according 1 of a CHP system according to
this disclosure can be as described hereafter.
[0054] In FIG. 1 schematically a heat exchanger 1 is shown, in
perspective view, generally from a second side. This heat exchanger
1 comprises a first part 2, a second part 3, a first end part 4 and
a second end part 5. In a heat exchanger 1 according to this
description at least one of the first and second parts 2, 3 and/or
the first and second end parts 4, 5 can be made at least partly by
extrusion. At least one of these parts 2, 3, 4, 5 is preferably
made of light metal, such as aluminium, aluminium alloy, magnesium,
magnesium alloy, or other metal. Preferably all parts 2, 3, 4, 5
are made at least partly by extrusion and at least partly of metal,
preferably light metal. As indicated, light metal can be understood
as at least including non-ferro metal having a density of 4500
kg/m.sup.3 or less.
[0055] In the embodiments shown at least two of the first 2 and
second part 3 and the first 4 and second end part 5 can be mutually
bonded together for forming at least one of a gas flow space 6 and
a water flow space 7. The gas flow space 6 and water flow space 7
can for example be formed by or comprise one or more channels or
ducts, especially at least one gas duct 6 and at least one fluid
duct 7, especially a water duct 7. The or each gas duct and/or the
or each fluid duct can comprise a series of sections 30 A-(N),
24A-(N), wherein (N) can be any number, especially parallel
sections, connected to each other for example in and/or by end
pieces 5, for forming a meandering and/or zig-zag patterned duct.
In the embodiment of FIG. 3 the second end part 5 comprises a first
and second channel part 8A, 8B, both having a length direction Lg.
The length directions Lg are in this embodiment parallel, such that
the end part 5 can be extruded in the length direction Lg. In each
of the channel parts 8A, 8B an opening 9A, 9B is provided, for
example by drilling. Screw treads can be provided in the openings
9A, 9B in order to connect piping 118, 112 to these openings, as
will be discussed later on. Other end parts and other types of
connections of the piping are also possible.
[0056] In this description bonding has to be understood as forming
an adhesive connection between two or more parts using an elastic
bonding agent. Especially suitable is a glue or adhesive which
after curing is still flexible and elastically deformable.
Preferably the bonding agent is heat resistant to temperatures
above 120.degree. C., preferably above 150.degree. C., more
preferably above 170.degree. C. A glue can be used having a
temperature resistance up to 180.degree. C. or above. A glue can be
used having a use temperature range between about -4 and
+120.degree. C., preferably between about -20 and +150.degree. C.,
more preferably between about -40 and +170.degree. C., even more
preferably between at least -55 and 180.degree. C. or higher (e.g.
PSI S406). A temperature range should be understood as a range of
temperatures in which the glue maintains at least most of its
elastic and bonding properties, such that in a heat exchanger at
least the bonding maintains pressure resistant and fluid and gas
tight. Pressure resistant is in this context to be understood as at
least resistant to pressures in an adjoining space of above 2 bar,
preferably above 4 bar, more preferably at least to 10 bar. The
desired pressure resistance can be as high as 20 bar or above. One
bar is 100.000 Pascal or 0.1 MPa. Reference can be made to adhesion
to peel, according to ASTM C794.
[0057] Elastic bonding agent, such as glue or adhesive should be
understood as an agent which, after curing, has during use, a high
yield strength and high yield limit. This means it can be stretched
to a relatively high degree before breaking The elasticity is
preferably such that the yield limit is more than about 300%,
preferably more than about 400%, more preferably more than about
550% and in particular preferably about 650% or more. Preferably
this high yield limit is maintained over the temperature range
during use of the heat exchanger. The yield limit can e.g. be
measured according to ASTM D412.
[0058] The bonding agent can be a silicone or elastomeric based
adhesive, preferably curing at about room temperature to a rubber
like component which is water and gas tight. A bonding layer formed
by said bonding agent is preferably pressure resistant to at least
about 4 Bar, more preferably to about 10 Bar and even more
preferably to about 20 Bar or above, wherein the bonding agent is
preferably applied to unprimed metal of the parts. An example of
such bonding agent is Dow Corning 7091, which has a normal
temperature range of use between -55 and +180.degree. C., and a
yield limit of about 680%.
[0059] All kinds of combinations can be contemplated of yield
limit, pressure resistance and temperature range.
[0060] Dow Corning.RTM. 7091 Adhesive/Sealant is a
high-performance, neutral-cure silicone that cures at room
temperature to a tough, flexible rubber, suitable for the use
described herein. Dow Corning 7091 remains flexible and stable from
-55.degree. to 180.degree. C. (-67.degree. to 356.degree. F.), and
is a one-component, non-sag sealant. It can have a tear strength of
86 ppi and a tensile strength of about 363 psi. This adhesive is
only provided by way of example and should not be considered
limiting the scope in any way.
[0061] By using such a flexible bonding agent parts of the heat
exchanger can be connected to each other, forming fluid, especially
water, and gas tight seals without having to add gaskets, seals or
the like, which will remain fluid and gas tight over a large
temperature range. Moreover, such seals are relatively inexpensive
and are pressure resistant to relatively high pressures.
Furthermore, due to the high flexibility, problems with different
expansion rates and directions of the different parts bonded
together are avoided.
[0062] FIG. 4 shown in perspective view a first part 2. This part 2
can be made substantially be extrusion. The part 2 shows a first
wall 10 and two second walls 11A, B. The first wall 10 is a
substantially hollow wall, defined by a first wall part 10A and a
second wall part 10B, for example extending substantially parallel
to each other, whereas a number of cross walls 12 extend between
the first and second wall parts 10A, 10B. The second walls 11A, B
extend at an angle .alpha. to the first wall 10. The angle .alpha.
differs from 180 degrees. The angle .alpha. is for example between
45 and 135 degrees and is preferably about 90 degrees. The walls
11A, B extend in a first direction from the first wall 10. One or
more of the second walls 11A can be lower than at least one other
wall 11B of the second walls 11. On the first side of the first
wall 10 an intermediate wall 13 extends, in the same direction as
the second walls 11. Between each of the second walls 11A, B and
the intermediate wall 13 a series of further walls 14 is provided,
extending in the same first direction from the first wall 10. As
shown in FIG. 4 the second walls 11, the intermediate wall 13, the
cross walls 12 and the further walls 14 all have a length direction
X and thus extend substantially parallel to each other. The free
ends 15 of the second walls 11 and the intermediate wall 13 can
have a groove 16 extending in the said length direction X, open to
a side facing away from the first wall 10.
[0063] As is shown in FIG. 4 to the right side of the intermediate
wall 13 the further walls 14 can have a reclining end 17, such that
the further walls 14 have a greater length XA near the first wall
10 than the length XB at the opposite free side 15 thereof. The
opposite end 18 of the further walls 14 can be straight, such that
the second ends 18 of the further walls 14 form a substantially
flat plane V extending substantially perpendicular to the first
wall 10, for example at a distance B from the opposite edge 20.
These further walls 14 can end at a distance A from the edge 19 of
the first wall 10. The intermediate wall 13 extends from the edge
19 to a distance B from the opposite edge 20 of the first wall 10.
The reclining ends 17 can in an alternative also be e.g. convex or
concave. The space created thereby can be narrowing in the
direction of the edge 20. Obviously the reclining ends can also be
substantially or partly convex of concave or have another regular
or irregular shape, providing said effect of a narrowing inlet
space 30, if such is desired. Otherwise they may also be
substantially straight.
[0064] As is shown in FIG. 4 to the left side of the intermediate
wall 13 the further walls 14 can have a straight end 21, such that
the further walls 14 have about the same length XC near the first
wall 10 as at the opposite free side 15 thereof. The opposite end
22 of the further walls can be straight, such that the second ends
22 of the further walls 14 abut the same substantially flat plane V
extending substantially perpendicular to the first wall 10. Some of
the further walls 14, positioned next to the intermediate wall 13
can end at a distance C from the edge 19 of the first wall 10. The
further walls 14 can extend the full length X of the first wall
10.
[0065] At two opposite outer sides of the second walls 11A, B a
profile 23 is provided, having a substantially circular inner cross
section. At the base of the intermediate wall 13 a further opening
23A can be provided, extending all the way through the relevant
part 2, 3.
[0066] This first part 2 can be made by extruding a continuous
length of profile having a cross section as for example shown in
FIG. 7. A desired length X.sub.1 can be sawn off from the
continuous length. Then part of the first ends 17 of the further
walls 14 can be removed, for example milled or sawn off, as can the
second end of the intermediate wall 13. Because of the open side of
the parts this is easily accessible for such machining In the
embodiment shown five cross walls 12 are shown, dividing the space
24 within the double first wall 10 into four parallel channel parts
24A, 24B, 24C, 24D. Different numbers of channels or channel parts,
which may also be referred to as sections can be used. The two
middle channel parts 24B, C are connected to each other by removing
part of the first end 25 of the cross wall 12 in between, whereas
the left hand two channel parts 24A, 24B in FIG. 4 are connected to
each other by removing part of the second end 26 of the
intermediate cross wall 12, adjacent the plane V. In a similar
manner part of the second end 26 of the cross wall 12 between the
right hand two channel parts 24C, 24D can be removed to connect
these two channel parts 24C, 24D. The channel parts 24 can thus
form parts or sections of a water conducting channel or duct 6.
[0067] FIG. 5 shows the first part 2 as shown in FIG. 4, from the
opposite second side. Here clearly the second ends of the further
walls 14 and the second walls 11 and intermediate wall 13 can be
clearly seen, forming a plane Ve, parallel to the plane V. Planes V
and Ve are imaginary planes.
[0068] Between the further walls 14 and between the walls 11, 13
and adjacent further walls 14 spaces 30 A-(N) are provided, such
that a substantially regular pattern can be formed. The second part
3 can be formed in a similar way.
[0069] In embodiments at the free ends of the walls 10 and 11, at
opposite ends seen in the length direction X.sub.C, bonding
surfaces B.sub.1 and B.sub.2 respectively can be formed. These
bonding surfaces are preferably flat and even. As is schematically
shown in e.g. FIGS. 5-9 and further and in larger detail shown in
FIGS. 14 and 15, these bonding surfaces can be provided with spacer
elements 52. These spacer elements 52 can be integral part of the
parts 2 and/or 3 and/or of end parts 4 and/or 5. The spacer
elements can be small elevations above the bonding surfaces B,
which can be provided by machining of said surfaces B, for example
milling. In another embodiment these spacer elements 52 can be
provided in or on the surface separately and e.g. be glued or
screwed in place. The spacer element extent to a relatively short
distance d.sub.1 above said bonding surface B, for defining a
thickness t.sub.1 of the bonding layer 53, as is shown in FIG. 15B.
In FIG. 14 a perspective view of a part of a first or second part
2, 3 or of an end part 4, 5 is shown, in enlarged view, showing a
substantially cylindrical spacer element 52. Obviously these spacer
elements 52 can have any desired shape or form, and a height
d.sub.1 depending on the desired, optimal thickness t.sub.1.
[0070] In FIG. 16A shows in side view a ridge 27 on a wall 11, 13
of a second part, by way of example only, whereas to the side of
said ridge 27 shoulders 54 are formed, as part of the wall 11, 13
having a larger width than the ridge 27. On each shoulder, or on
only one if desired, at least one spacer element 52 is provided,
again having a relatively low height d.sub.1 above the surface of
the shoulder 54. This can for example be a ridge extending over a
length of said wall 11, 13, or one or more shorter elements, such
as for example pins, ribs or the like. In FIG. 16B such spacer
elements 52 are shown on the end surface of the wall 11, to the
sides of the groove 16. Again the height d.sub.1 is relatively
small. Similar elements can be provided on top of the ridge 27, to
the sides thereof and/or at the bottom 56 of the groove 16. In FIG.
16B the bonding layer 55 is sketched in by phantom lines, as an
indication. Preferably the space between the ridge 27 and the inner
wall of the groove 16 has a width t.sub.1 similar to the height
d.sub.1 of the spacer elements 52. The
[0071] The spacer elements 52 have the advantage that they define
the minimum space between two opposite bonding surfaces B of for
example the first and second parts 2, 3 and/or the end parts 4, 5,
thus defining the thickness t of the layer of bonding agent, and
more specifically defining an even thickness thereof over the
entire relevant surface B, or between the ridge 27 and the groove
16 cooperating therewith. This means that the optimal amount of
glue can be used, reducing costs, whereas the best bonding and
sealing can be obtained easily with the relevant bonding agent.
This is obtained by at least one bonding surface B abutting the
spacer elements 52 on the at least one other bonding surface it is
to be bonded with, preventing it from being pressed closer to said
bonding surface. The height of the spacer elements 52 above the
relevant bonding surface B can be in the order of tenth's of
millimetres or less, e.g. between 0.01 and 1.5 mm, preferably less
than 1 mm. Obviously the height and thus the thickness of the layer
can be chosen dependent on the characteristics of the bonding agent
used, for optimisation. By minimizing the thickness of the layer of
bonding agent 55, the transfer of heat between the parts bonded
together will be maintained. Moreover, due to the fact that one of
the parts will be in direct contact with the or each other part it
is bonded to by the abutting contact between the bonding surface of
one of said parts with spacer elements on another bonding surface
it is bonded too, there will be direct metal to metal transfer of
heat, which will further optimize the heat transfer.
[0072] It will be clear that in a heat exchanger according to the
present disclosure also other means for connecting the parts can be
used, such as welding, clamping, bolting, with or without a seal
such as a packing or closure ring or similar means known in the
art.
[0073] In FIG. 8 a partly assembled heat exchanger 1 is shown, in
side view, in which at least a first 2 and second part 3 are shown,
assembled. In FIGS. 7 and 8 respectively the first part 2 and the
second part 3 are shown, equally in side view. As can be seen the
second part 3 has a cross section similar to that of the first
part, but the second walls 11C, 11D and the intermediate wall 13B
have heights such that when positioned on the second walls 11A, 11B
and 13 respectively, the first wall 10 of the first part 2 extends
parallel to the first part 10 of the second part 3, thus forming a
substantially rectangular cross section. The second walls 11C, 11B
and the intermediate wall 13 of the second part 3 have ridges 27
that can fit in the grooves 16. The further walls 14 of the first
part 2 can extend between the further walls 14 of the second part
and/or between a fin and either a second wall 11C, D or the
intermediate wall 13 of the second part. The further walls 14 can
have a substantially triangular or trapezoid cross section with a
base 28 near the respective first wall 10 broader than the free
side thereof.
[0074] As can be seen the channel parts 24 of the first walls 10
can have a ribbed or otherwise corrugated or channelled surface, at
least at the side of the further walls 14, in order to increase the
heat exchanging surface of the channel parts 24. Heat of the
intermediate walls can be transferred to water in the channel parts
24 through the first wall 10. The heat exchanging surface
increasing profile of the channel parts 24 will increase the
effectiveness of this heat exchanging when water is transferred
through the channel parts 24.
[0075] For all channels or ducts or parts of sections thereof, but
especially for the gas channel or duct or sections thereof such
heat exchanging surface increasing ridges preferably extend in the
direction of flow of gas or fluid through said channel part or
section, thus not forming an obstruction for linear flow. In other
embodiments the walls can be free of even such elements. At least
there are no such elements extending from the wall into the
relevant part or section of a channel, forming an obstruction to
linear flow of the gas or fluid through said section or part of a
duct or channel.
[0076] The first part 2 can be bonded to the second part 3, by
bonding the second walls 11A, B of the first part 2 to the second
walls 11C, D of the second parts 3. The intermediate wall 13 of the
first part 2 can also be bonded to the intermediate wall 13 of the
second part 3. Preferably at least the ridges 27 can be bonded in
the grooves 16. Bonding can be achieved by glue, for example
acrylic glue, two or more component glue, PLEXUS MA 420, PERMABOND
ES 550 or DOW CORNING 7091. As can be seen in FIG. 6 preferably the
grooves can have an open side having a width slightly less than the
adjacent part of the groove 16, whereas the ridge 27 can have a
width substantially similar to the width of the open side. This
means that glue in the groove 16 will be locked in the groove by
forcing the ridge 27 into the groove 16, whereas the ridge 27 will
be centred within the groove 16, when the opening is provided
symmetrically. The space between the ridge 27 and the walls of the
groove 16 is preferably similar in width to the height of the
spacer elements 52, such that a layer of bonding agent can be
formed between said ridge 27 and groove 16 similar in thickness as
that between the bonding surfaces as discussed before.
[0077] When an embodiment of a ridge 27 and/or groove 16 is used as
disclosed in FIG. 14A and B, spacer elements 52 can again be used
for defining the thickness of a layer of bonding agent.
[0078] As can be seen in various figures, the spacer elements 52
can be distributed over all or some of the bonding surfaces B
and/or end parts 4, 5. Preferably they can at least be provided on
first walls 10 near partition walls 12 and near walls 11 and 13, as
well as on the walls 11 and 13. Moreover they can be provided for
example at feet 50. Preferably they are distributed such that
pressure applied to the parts and, especially, the end parts 4, 5
does not significantly bend or otherwise deform any surface in
between the spacer elements 52. The spacer elements 52 are
preferably provided at a short distance from a or, more preferably,
at a distance from each of the sides of the relevant bonding
surface they are provided on. This has the advantage that the
bonding agent can surround the spacer element 52 at least partly
within the layer of bonding material, or at least form a continuous
seal between the bonding surfaces B alongside the spacer elements,
and preferably can surround the spacer elements 52 entirely, for
forming both a good adhesion between the bonded parts and a good
sealing. Again, the direct contact between the metal parts through
the spacer elements will improve the heat transfer between parts.
The relatively small thickness of the bonding layer 55 will
furthermore prevent thermal isolation further. Moreover this
prevents too flexible seals.
[0079] FIG. 9 shows a partly assembled heat exchanger 1, open at
the first side, showing the second walls 11A, C and 11B, D bonded
to each other, as well as the intermediate walls 13. Between the
first walls 10 and the second walls 11 of the first and second
parts 2, 3 a heat exchanging space 30 is defined, at least partly.
At two opposite sides of the space 30 in the respective first wall
10 a channel 24 is provided for e.g. water. A second end part 5 is
partly visible at the second side of the heat exchanger 1. At the
first side the further walls 14 are visible. At one side of the
intermediate walls 13 the reclining ends 17 of the further walls 14
are shown. Between the edge 19 and the ends 17 of the further walls
14 a inlet space 31 is provided. In the inlet space 31 exhaust gas
from the engine or turbine 104 can be fed. The reclining ends 17
are provided to prevent undesired tension in the intermediate walls
17. At the opposite side of the intermediate walls 13 a space 32
can be provided, in order to reduce flow resistance and improve the
heat exchange between heated gas flowing through the space 30
between the further walls 14 and/or the intermediate walls and the
walls 11, 13.
[0080] In FIG. 10 a heat exchanger 1 is shown, similarly to FIG. 9,
but with a first end part 4 at the first side of the heat exchanger
1. The first end part 4 can be bonded, such as glued to the first
and second parts 2, 3. Similarly the second end part 5 can be
bonded, such as glued to the second side of the heat exchanger 1.
Again spacer elements 52 can be used for defining the optimal or at
least desired thickness of the layer of bonding agent. In the first
end part 5 a first opening 33 is provided, opening into the inlet
space 31. A second opening 34 is provided, opening into the space
32. In and/or over the first opening 33 the inlet pipe 106 can be
connected, as is shown in FIG. 12. In and/or over the second
opening a gas exhaust 35 can be connected, as is shown in FIG.
12.
[0081] As can be seen in FIGS. 10 and 11 in an embodiment the
channels 8A, B can extend beyond the periphery of the first and
second parts 2, 3. In the embodiment of FIGS. 10 and 11 the
channels parts 8A, B extend in opposite directions beyond the
periphery. They can however also extend in the same direction. In
each of the extending portions 35A, 35B an opening 9 is provided,
for example by drilling or milling, preferably provided with
internal screw threads or another means for attaching a pipe of a
heating circuit. An inlet of a heating circuit can be connected to
one of the openings 9, an outlet of the heating circuit to the
other opening 9. The openings 9 are preferably provided in a wall
38 of the channels facing in the direction of the first and second
part 2, 3 of the heat exchanger 1. This can provide a compact heat
exchanger and easy access. The open ends 36 of the channels parts
8A, B can be closed off by stops 37, as is shown in FIG. 3. The
stops can also be bonded such as glued. In the wall 38 of each of
the channel parts 8A, B at least one further opening 51 can be
provided, opening into a channel part 24 inside a first wall 10,
for fluidly connecting the channel part 24 with the channel part 8
and thus with the relevant opening 9. In the embodiments shown in
FIGS. 3 and 10 one channel part 8A is connected to a first channel
part 24A of each of the first walls 10, whereas the other channel
part 8B is connected to the last channel part 24D of the first
wall. In the embodiments shown this is the fourth channel part 24D
but obviously other numbers of channel parts can be provided,
whereas the channel parts 8A, B or further such channel parts 8 can
be connected to other channel parts 24 or even to each of the
channel parts 24, depending on the desired flow paths of the water
through the walls 10.
[0082] The first and/or second end parts 4, 5 can basically be made
by extrusion, the extrusion direction in the length direction
L.sub.8 of the channel parts 8A, B. For an embodiment of for
example FIGS. 10 and 11 parts of the wall 38 can be removed, for
example by milling or sawing, to provide for the extending portions
35A, B. Openings 9 can be provided then by for example drilling or
milling. The end parts can be bonded, such as glued, to the first
and second parts 2, 3. The end parts 4, 5 can be provided with
further openings 39. When assembling the heat exchanger bolts or
rod with ends provided with screw threads can be inserted through
these openings 39 and the channels 23 or openings 23A extending
there behind, after which nuts can be screwed onto the bolts or
screw thread of the rods, in order to further clamp the end parts
4, 5 to the first and second parts 2, 3. This can provide for
further mechanical strength.
[0083] In FIG. 12 schematically a gas flow path is shown, through
the inner space 30 of a heat exchanger 1, between the inlet space
31 and the exhaust 35. As can be seen exhaust gas from the engine
or turbine can flow, as indicated by arrows G from the inlet space
31, into the spaces 30A-(N) between the further walls 14 and/or
intermediate walls 13 and adjacent walls 11, 13. At the second side
opposite the inlet space 31 the gas can flow between the end part 5
and the end 19 of the intermediate wall 13, in to the spaces
between the further walls 14 in the space between the second end
part 5 and the exhaust 35. From there the gasses can flow into the
exhaust 35 to be expelled. A condensate drain 40 can be provided in
or next to the exhaust 35.
[0084] In a CHP of the present disclosure the main direction of
flow of gas and/or water in the heat exchanger can be in a
substantially horizontal plane. This allows for a compact design of
the unit 100 without increasing problems with contamination. The
positioning may be chosen such that there is a slight angle towards
the exhaust 35, for draining condensate from the gas duct 6.
[0085] As can be seen in FIG. 12 in this embodiment the length of
the further walls 14 in the space between the second end part 5 and
the exhaust can vary, such that the intermediate walls closest to
the intermediate wall 13 are longer then intermediate walls closer
to the second wall 11B and the space 32 has a substantially
trapezoid shape. This can have the advantage that all gasses
flowing through the space 30 have about the same contact with
intermediate walls, independent of their flow path.
[0086] In FIG. 13 schematically a water flow path is shown through
the first walls 10 and the channel parts 8A, B. In this embodiment
water is provided to the heat exchanger 1 through an inlet 41 into
the channel part 8A. The inlet 41 is shown as comprising a pipe 42
extending from a heating circuit 123, schematically shown in FIG.
13 without for example the containers 111, 131 and the additional
boiler 135, and shown as having a pump 142 and a radiator 45, and
connected to the relevant opening 9 by the pipe 118. In other
embodiments this can for example be a household water or sanitary
water supply, a boiler, or other means using heated water or other
heated fluids or gasses. The water flowing from the inlet 9A, 41
flows into the channel part 8A and is divided over both channels 24
in the respective first and second part 2, 3. In FIG. 13 only one
of these channels 24 is shown. The water then flows through the
channel parts 24A-D, along the cross walls 12, to the other 8B of
the two channel parts 8 as is shown by arrows W, through which the
water from both channels 24 can flow into an outlet 9B, 45, here
shown as a pipe 46 connected to the heating circuit 43 through pipe
112.Thus heat can be exchanged between the exhaust gasses flowing
through the space 30, especially the gas duct or ducts 7 and the
intermediate walls and walls, especially walls 13 and 10, which
heat can then be transferred to water or other medium flowing
through the channels 24, to be used in the heating circuit 199,
123. The flow through the channels 24 and the space 30 if
preferably such that water and gas have counter flow directions as
much as possible. This can for example be obtained by positioning
the inlet 41 in the second end part 5 at the exhaust 35 side of the
intermediate wall 13, the outlet 45 being provided on the opposite
side of the intermediate wall 13, in the second end part 5.
[0087] As will be understood the bonding agent such as glue used
for bonding different parts of the heat exchanger 1 to each other
preferably provides a sealing between these parts too, which
provides for a water and gas tight connection without the necessity
of further sealing means such as seals. In other embodiments
sealing of at least some of the parts relative to each other can be
obtained through other means, such as seals, gaskets or the like
sealing means. By using an elastic bonding agent for connecting and
sealing parts of the heat exchanger, the surprising advantage is
obtained of lower cost, and better sealing than when a hard or
hardening agent is used. Moreover, due to the bonding, especially
in combination with spacer elements, the connection can be made
strong and gas and fluid tight, as well as pressure resistant.
[0088] A heat exchanger 1 according to the present invention is
relatively easy to produce, is economical in comparison to heat
exchangers having the same capacity made by for example moulding or
welding, and can easily be adapted for for example different
capacities, set up such as amendment of the position of the inlet
and/or outlet 41, 45, the inlet 31 and the layout of the channels
24 and further walls 14. Moreover, a range of heat exchangers 1 can
be provided, differing basically only in the length X.sub.1 of the
first and second part 2, 3. These different heat exchangers will
have different capacities, depending on and mainly in relation to
the length X.sub.1. This means that with the same extrusion tools
different heat exchangers can be made, reducing production
costs.
[0089] The first and/or second part 2, 3 can be provided with
flanges 50 for supporting the heat exchanger.
[0090] In embodiments the heat exchanger can comprise a body,
preferably a mono-block body closed by end parts, the body having
been extruded and comprising the or each flue duct and the or each
fluid duct.
[0091] The walls defining the or each gas duct or channel or part
or section thereof, made by extrusion, preferably has a very low
surface roughness, which mat be as low as about 1 Ra or less, for
example about 0.8 Ra or less. Such surface roughness is preferably
obtained substantially without machining after extrusion. As
indicated each flue duct and/or fluid duct can comprise a series of
parallel sections, meaning that these sections has substantially
parallel main directions of flow. These may be alternatingly in
opposite directions or at least one series of such sections can
have a same direction of flow, opposite to the direction of flow of
at least one series of such sections. The at least one flue duct is
preferably straight or has parallel sections which are straight,
wherein a flow direction of gas through said at least one flue duct
or said parallel sections thereof is parallel to a extrusion
direction of said duct or duct section.
[0092] In at least one outer wall of the or each flue duct 7 at
least one closable opening can be provided for inspecting and/or
cleaning the duct or relevant parts thereof. Since the duct is free
of obstructing elements such cleaning is easily possible.
[0093] A heat exchanger 1 according to this description can be used
as a "stand alone" heat exchanger, for supplying heated medium such
as water. In another embodiment the heat exchanger can be used as a
"add on" heat exchanger, for example coupled to other heating or
power generating means, such as heating devices using "green"
energy, electrics, natural gas or the like. Also a number of these
heat exchangers can be connected, such that depending on heat
demand one or more of these heat exchangers can be fired up to
provide heat.
[0094] The invention is by no means limited to the embodiments as
shown and/or described in this description. Many variations thereof
are possible within the scope of the claims, including at least all
combinations of parts and elements of the embodiments and parts
thereof shown, in any combination or permutation. For example one
or both of the walls 10 can be made having separate channel parts
above or next to each other for connecting to separate water or
other medium circuits. Moreover the first and/or second parts can
have other cross sections and can for example have reclining second
walls, for providing a larger space 30. The parts can be attached
to each other using different means, such as screws, fasteners,
clamps, welds or the like. Also other bonding agents can be used,
for example two or more component agents. Moreover, the even
thickness of the bonding layers and heat conducting properties
through the connection thus formed can be achieved in another way,
for example by gluing tools and moulds used for exact positioning
of the parts during bonding, and/or by providing heat conducting
elements connected to both parts, such as but not limited to pins,
strips or similar, preferably metal elements inserted in between
the bonded parts or to them, crossing said bonding connection. In
other embodiments a first part 2 can be used having second walls 11
and intermediate walls 13 extending from both sides of the first
wall 10, as well as further walls 14, whereas two second parts 3
can be provided at the two opposite sides of the first part 2,
providing a space 30 to each side of the first wall 10 of the first
part 2. These spaces 30 and the water channels 24 of the different
parts 2, 3 can be used for the same or different heating circuits.
Shapes and dimensions, as well as positions of the different parts
can be changed within the scope of the claims as pending. Moreover,
more or less channel parts 8, 30, 24 can be provided than shown,
whereas more than one intermediate wall can be provided, for
example two or more, in each of the first and second parts 2, 3,
whereas the channel parts, burner and exhaust can be provided in
different positions. These and other alterations and modifications
are supposed to be disclosed within the scope of the claims.
* * * * *