GB2459927A

GB2459927A - Heating appliance including a modular heat pump partially housed within a flame effect fire

Info

Publication number: GB2459927A
Application number: GB0808686A
Authority: GB
Inventors: Barry Charlton; Peter Mintoft
Original assignee: Charlton and Jenrick Ltd
Current assignee: Charlton and Jenrick Ltd
Priority date: 2008-05-14
Filing date: 2008-05-14
Publication date: 2009-11-18
Also published as: GB0808686D0

Abstract

Heating arrangement 100 includes an insert assembly having a visible panel 200 and modular heat pump, partially housed (hidden from view) in a flow path 201 extending behind panel 200, the heat pump including a flow heat exchanger 3 in flow path 201, an external heat exchanger 4, and a compressor 1 and expansion valve 2 locatable either in (fan 8 assisted) flow path 201 or externally away from flow path 201, dependent upon accommodation, to maintain a desired cross sectional area for flow path 201 and desired heat transfer between flow exchanger 3 and external exchanger 4. Panel 200 may include a screen 15 to receive a projection from a projector 13 to simulate flames, and include a fuel effect surface 14 (e.g. coals, wood), illuminated by fuel effect apparatus 11. Arrangement 100 may include a switch valve 5 to alternate flow exchanger 3 from a condenser (heater) to an evaporator (cooler). Flow path 201 may be filled with a fluid (e.g. oil, water) to act as a storage heater/cooler.

Description

A Heating Arrangement The present invention relates to heating arrangements and more particularly to heating arrangements to emulate a solid fuel fire in a domestic S environment.

Solid fuel fires have been used for generations to provide heating within domestic environments. There is a degree of nostalgia as well as familiarity associated with such solid fuel fires. However, reduced desirability of using such solid fuel as well as inefficiencies have led to increasing 1 0 provision of gas and electric fires which emulate solid fuel fires. These gas or electric fires include imitation coals and with regard to gas fires the gas will typically be presented through the coals when burnt whilst with electric fires a means for simulating solid fuel burning effects will be created through lighting or projected imagery. In the above circumstances it will he understood that a heating arrangement is arranged to provide a useful source of heat possibly in combination with a primary heating system such as a central heating system for a boiler as well as to provide sole heating in a dwelling but always to present a pleasant ambience and atmosphere.

Generally electric heating arrangements to provide a fireplace have utilised electrically resistive heating or radiant heating to varying degrees.

Generally traditional electric fires have a coefficient of performance where the electric energy is used in a resistive element to provide heat of in the order of 100% of the electric energy input. However, heat pumps have a coefficient of performance in the range 240% to 510% of the energy performance of a typical electrical resistance fire arrangement. The degree of efficiency being dependent upon the type of system used as well as control regimes.

Heat pumps comprise a device that transfers heat from one location to another using effectively intermediate electrical power and a refrigerant fluid to perform the work. A simple description of a heat pump is a fridge without an insulating cabinet. In such circumstances through the refrigerant work fluid being compressed and expanded heat can be transferred in order to provide cooling or heating either side of a heat exchanger. Figure 1 provides a schematic illustration of a typical heat pump. In such circumstances the heat pump 1 comprises an evaporator 2 in the form of a heat exchanger, a condenser 3 in the form of a heat exchanger and a compressor 4 with an expansion valve 5. In terms of operation it will be understood in order to provide a cooling function such as air conditioning the condenser 3 is generally presented outside of the area to be chilled. For cooling the evaporator 2 is located within a house or area to be cooled. Alternatively, the evaporator may be positioned to transfer heat to or from water in a wet heating system. The refrigerant within the circuit created by the exchangers 2, 3, compressor 4 and expansion valve 5 generally arrives at the compressor 4 as a low pressure gas and.the compressor in such circumstances does compression work upon the refrigerant. The refrigerant then leaves the compressor typically in a hot compressed gas form and flows to the condenser 3. For cooling, the hot refrigerant gas is then put through the condenser 3 in the form of a heat exchanger such that a stream of air in the direction of arrowhead A causes the gas to condense to a high pressure liquid. The high pressure liquid then passes through the expansion valve 5 typically in the form of a tiny hole into the evaporator 2. Such expansion causes a rapid pressure drop such that the refrigerant will expand into a gas once more. During such expansion the fluid absorbs heat from its surroundings through the exchanger 2 reversing, the heating process undertaken by the compressor 4. Generally in order to take full advantage of such cooling processes a cooling fan forces air in the direction of arrowheads B through the evaporator 2. The refrigerant then leaves the evaporator 2 as a cool low pressure gas for re-compression by the compressor 4 again to begin the refrigeration cycle.

It will be understood that a heat pump 1 can operate as a cooler or a heater by reversing the refrigerant flow through the pump 1. In such circumstances the functions of the heat exchanger 3 and the heat exchanger 2 can be switched.

Utilising the above process heat pumps can be used in a number of situations including extracting heat from or rejection of heat to ground or air.

Furthermore, heat pumps can be utilised with respect to water heat distribution systems in a similar fashion to a boiler or air heat distribution systems within a building utilising appropriate fans. As with other heating arrangements it will be understood that a thermostat is generaHy utilised to sense the temperature and turn the heat pump on and off. In the above circumstances relatively high levels of efficiency can be achieved through provision of electrical energy to the compressor 4 in order to achieve the heat pumping effect in either direction between the heat exchangers defined in the evaporator and the condenser. Broader application of heat pumps in such circumstances will be advantageous with regard to domestic and other heating arrangements. However, heat pumps by their very nature are utilitarian and generally relatively bulky rendering t difficult to achieve IS acceptability in domestic. environments where aesthetic appearance is important and accommodation space limited particularly with regard to retro fitting of a heating appliance in a previous fireplace utilised for a solid fuel or gas fire.

In accordance with aspects of the present invention there is provided a heating arrangement comprising an insert assembly for an accommodation space, the insert assembly having a visible panel and a modular heat pump including a heat pump part hidden in a flow path extending behind the visible panel, the heat pump part comprising at least a flow heat exchanger and predetermined remaining parts of the modular heat pump including an external heat exchanger, a compressor and an expansion valve combined dependent upon accommodation within the flow path or externally away from the flow path to maintain a desired open cross sectional area for the flow path and a desired heat transfer between the flow heat exchanger and the external heat exchanger.

Typically, the flow path incorporates a fan or other means for stimulating flow.

Generally, the flow path extends from below the visible panel to above the visible panel.

Possibly, the flow path has an entry and/or exit defined by a grille.

Typically, the visible panel comprises a screen to receive a visual projection in use. Possibly, the visual projection is of an active flame.

Possibly, the visible panel incorporates elements to provide a solid fuel external appearance.

Possibly, the flow path includes a liquid vessel to allow heat exchange to the liquid by the flow heat exchanger.

Generally, the flow heat exchanger is elongete to extend along a proportion of the flow path. Possibly, the flow heat exchanger is compressible and/or adjustable in terms of width for accommodation within the flow path.

Generally, the flow heat exchanger and the external heat exchanger can be configured alternately as a condenser or evaporator within the modular heat pump. Typically, the modularheat pump comprises components of units sized to allow assembly of a number of such components dependent upon the available, dimensions of the flow path.

Typically, the arrangement incorporates an integrated cabinet to present the visual panel and the flow path. Generally the integral panel is arranged toextend into a recess in use. Possibly, the flow path is defined between a rear portion of the visible panel and an opposite part of a recess within which the heating arrangement is located. Possibly, the recess is specifically formed to receive the arrangement in a wall.

Generally, the compressor of the modular heat pump is driven by an electric motor.

An embodiment of aspects of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 2 provides a schematic illustration of a heating arrangement in accordance with aspects of the present invention; and, Figure 3 is a schematic cross section of the arrangement as depicted in figure 2.

As indicated above traditional gas fires are efficient at up to 9Q% when conventional flue or with a balance flue Or even up to approaching 100% with flueless appliances. Balance flue fires are probably most convenient and offer significant advantages by requiring no ventilation within a room in comparison * . . with. conventionally flued fires or flueless fires which require ventilation for safe operation. Permanently open ventilation causes unnecessary heat loss from such openings and in such, circumstances are preferably avoided. R will also be understood that gas. fires clearly utilise fossi' fuels and generally cannot achieve the zero carbon advantage of heat pumps and have difficulty in meeting the efficiencies of heat pump technology.

Although advantageous heat pumps are generaly utilitarian in nature.

As indicated.abo'e generally heat pumps incorporate respective heat.

exchangers and i,n such circumstances the appearance of the heat pump is generally not attractive and certainly has difficulty providing the necessary emulation of a traditional fireplace whether that be a gas, electric or solid fuel fire.

* Aspects of the present invention relate to providing a heating appliance which combines a heat pump with components to emulate a traditional fireplace. The heating arrangement comprises a visual panel which is the externally visual part of the appliance whilst a heat pump is provided in a modular form such that an area behind the visual panel can be utilised dependent upon the space available to accommodate pants of the heat pump.

Thus, aspects of the present invention combine the efficiency and inherent low carbon technology of heat pumps with visual panels which create the effect of a solid fire in terms of flame effect and imitation coals. In such circumstances by combining a modular heat pump and a visual panel a complete arrangement is provided which meets the needs of a homemaker in terms of creating a traditional fireplace whilst improving efficiency in terms of low carbon and efficiency of performance.

Aspects of the present invention as illustrated in figure 2 create as seen in the schematic perspective view a heating arrangement 100 which comprises a grille 12, coals 101 and a hood 102 within the arrangement 100 * such that within a surround 103 a heating arrangement is provided which emulates a prior fireplace. The whole arrangement 100 is generally provided * effectively as an integral assembly which can be located within a recess aperture fireplace in a domestic home environment.

As depicted in figure 3 the arrangement 100 generally comprises a visual panel 200. The visual panel 200 generally comprises a projection screen 15 which receives a projection from a projector 13. This projection is generally a film effect presented upon the screen 15 in order to emulate flames rising from coals in a coal effect surface 14. It will also be understood that the coals 14 will typically be illuminated by a fuel effect apparatus 11 such that the visual panel 200 gives the appearance of a traditional fire.

In accordance with aspects of the present invention a heat path 201 is created behind the visual panel 200. The flow path 201 is associated with the grille 12 and the hood 102 such that hot air moves in the direction of the arrowheads depicted. Typically the fluid flow in the flow path 201 is stimulated by a fan 8. The fan 8 may be variable in terms of flow rate for air movement through the path 201. In accordance with aspects of the present invention as indicated a modular heat pump arrangement is provided. At least a part of that heat pump arrangement in the form of a heat exchanger 3 is accommodated within the flow path 201. As indicated the heat pump is modular such that beyond the minimum heat exchanger 3 which can be defined as a flow heat exchanger other parts of the heat pump can be located within the flow path 201 as required. Thus, although not depicted a compressor 1 and expansion valve 5 can also be accommodated within the flow path 201. Generally, as indicated the heating arrangement 100 in accordance with aspects of the present invention is located within an existing recess forming a fireplace in a domestic dwelling. In such circumstances the panel 200 opposite a recess surface can define the flow path 201, However generally a casing 10 will be provided such that the arrangement 100 can be 1 0 conveniently located as an integral cassette or assembly into the recess when required. In such circumstances the part or parts of the heat pump in the flow path 201 will simply incorporate couplings to allow association with the main part of he modular heat pump. Thus, the expansion valve 2 can be located as indicated just to the rear of the recess or casing 10 or within the flow path IS 201 as required.

Other parts of the heat pump as indicated will comprise the compressor 1, an external heat exchanger 4 and a change over valve 5 there may also be a further fan 17 to stimulate air flow through the external heat exchanger 4. In such circumstances as described above the modular heat 1)L1P can be arranged to operate either to provide heat into the flow path 201 or remove heat from that flow path in order to create a heating or cooling effect. In such circumstances the change over valve 5 changes the direction of flow through the heat exchanger in order to stimulate the desirable heating or cooling effects alternately in the exchangers 3, 4.

In accordance with aspects of the present invention piping 6 is provided from the part of the modular heat pump within the heating arrangement 100 to other parts. It will be appreciated that limiting the distance of such piping may be advantageous in terms of operational efficiency. in such circumstances it is by providing a modular heat pump in which only parts of the heat pump which are acceptable for maintaining an appropriate flow within the flow path 201 enables design choices with regard to the extent of such piping 6 and therefore the necessary power and operability for the compressor 1 to achieve efficiency with regard to compression of the working fluid and expansion as required.

A further feature of aspects of the present invention is that as the heat pump is of a modular construction it will be appreciated that modular components of the heat pump can be defined such that respectively different size or relative efficiency or otherwise specified components of the modular heat pump can be chosen for a particular installation of a heat arrangement in accordance with aspects of the present invention. Thus, the compressor 1, the expansion valve 2 and the relative sizes of the flow heat exchanger 3 and the external heat exchanger 4 can be adjusted to meet particular installation requirements. It will be understood, that prior arrangements as indicated are generally of a utilitarian construction and therefore such flexibility in terms of performance and requirements cannot be easily matched. By providing a combination in a heating arrangement 100 in accordanca with aspects of the present invention the heat pump in terms of modular components as well as performance can be matched with the particular requirements for an installation. The heat pump is essentially hidden behind the visual panel 200.

In such circumstances the part of the modular heat pump presented within the flow path 200 can be. designed and. specified with no consideration with regard to aesthetic appearance. In. suh circumstances ribbing and fins and otherwise can be provided to enhance performance with regard to heat transfer using the pumping effect as described above.

It will be noted that the flow heat exchanger 3 will generally take an elongate form to allow heat exchange substantially along the length of the heat exchanger 3. It will be understood that generally heat exchangers in the form of matrices as illustrated with, regard to the fan 17 and external heat exchanger 3 are typically arranged such that the major air flow is in the direction of arrowhead. B, that is to say substantially perpendicular to the principal longitudinal aspect of the heat exchanger 4. *Such an approach is generally most convenient with regard to heat exchange with an air flow in the direction of arrowhead B over a broad front. Such an approach may facilitate relatively high heat exchange with a relatively large volume over the broad front of warmed or cooled air. However, with regard to the flow path 200 it will be noted that generally the flow heat exchanger 3 is presented with a substantially longitudinal aspect such that the air flow in the direction of arrowhead C is over a relatively narrow front but for a greater length of the flow path 202. Such an approach and configuration will typically allow heating to a higher temperature of a potentially smaller volume of air for warming or cooling effects, at least proportionately or relatively to the air flow and cooling or heating effect in terms of volume across the external heat exchanger 4.

Potentially a smaller volume of flow 0 output through the hood 102 will be heated or cooled as required. By provision of a modular configuration for the heat pump components. it will be understood that the configuration and in particular the elongevity of the flow heat exchanger 3 can be chosen for particular requirements within a heating arrangement 100 in accordance with aspects of the present invention.

As indicated above heating arrangements 100 in accordance with aspects. of the present invention are particularly specified for limited accommodation in terms of volumes or envelopes, it wUl be understood that the visible panel 200 is generally, specified in order to achieve a desired emulation of a solid fuel or other pleasant and homely configuration. Thus it is necessary to accommodate the projector 13 as wel! as an appropriate angularity with regard to the screen 15 and coals 14/101. In such circumstances in order to be realistic the visual panel 200 generally requires a certain depth. It may be possible simply to have a fixed and static pictorial representation of a solid fuel fireplace with appropriate back lighting but this will generally not be as acceptable to users. In such circumstances the depth of the visual panel 200 will limit the flow path 201 in most installations. By providing a modular approach to the heat pump design it will be understood that for the same visible panel 200 within the arrangement 100 different flow heat exchangers 3 can be utilised. In such circumstances if there is limited space a smaller flow heat exchanger 3 may be used such that there is a compromise in terms of potential heating capability whilst in other installations where the flow path 201 is greater as the visual panel 200 only comprises a reduced depth of the recess then a larger heat exchanger 3 may be utilised.

The objective is to achieve an efficient operational performance. As indicated the piping 6 external to the recess or casing 10 may be considered a source of inefficiency. This piping 6 will not be efficient in terms of heat exchange but generally will contain working fluid. This working fluid must be compressed and expanded for the heating and cooling effects by the compressor 1 and therefore presents a limitation to efficiency. It will be understood that ideally the compressor 1, expansion valve 2 and the respective heat exchangers 3,4 as evaporators and condensers in a conventional heat pump scenario should be as close together as possible. In such circumstances Within reason, there is immediacy between the functional components 1, 2, 3, 4 with the minimal amount of working fluid utilised. Any working fluid in pai's such s the pipe 6 as indicated is neither providing expansion nor condensation in the most efficient manner and therefore is a limitation. By a modular heat pump construction in accordance with aspects of the present invention as many of the components as possible can be located within the casing 10 or recess with only a minimal amount of piping 6 to an external location which may be in a chimney or directly through an external wall to the external heat exchanger 4.

It will be understood that the compressor 1 is generally driven by an electric motor using electric power supply 16. In such circumstances it will again be appreciated that there are advantages with regard to mounting the compressor 1 within the casing 10 where possible but accommodation space in some circumstances may be available within the casing 10 or recess or not.

Electrical power supply 16 may be ganged with the electrical power supply for the fan 8 if the compressor 1 is located within the casing 10 or recess so avoiding adding a further electrical power supply for the compressor 1 at its external location if possible.

Aspects of the present invention allow configuration of the casing 10 or a recess cowling such that as much of the heat pump apparatus as possible can be accommodated within the casing 1 where possible but where not the couplings from the minimum flow heat exchanger 3 within the flow path 201 allow external location of the expansion valve 2, compressor 1 and switch valve 5 along with the external heat exchanger 4.

In terms of installation it will be appreciated as indicated that flow through the heat exchanger 3 wilIbe chosen in order to provide the necessary level of heat exchange whether that be cooling or heating. Additionally, the heat exchanger. 3 may sit at least partially within a fluid tank. In such * circumstances the heat exchanger may heat that fluid in order to provide a back "boiler" facility with regard to the heating arrangement 100. The flow heat exchanger 3 in such circumstances will allow hesting of the water to provide a heated water supply. Alternatively, the water may be cooled or frozen by the flow heat exchanger 3 as a thermal store for later utilisation with regard to providing a chilling air conditioning effect. In such circumstances at times of low demand the water would be chilled to a frozen state such that at times when there is a high cooling demand the frozen volume of ice in.

addition to the flow heat exchanger effect can be utilised to achieve higher levels of cooling effect in the outflow D than is the base capacity of the heat exchanger 3. Alternatively, the flow heat exchanger coUld sit in a volume of oil or thermal bricks to again provide a hot thermal ballast.

In accordance with aspects of the present invention it will be understood that an air or ground source heat pump is defined with an indoor section in the form of the flow or indoor heat exchanger 3 generally installed in a recess or casing or housing typically associated with a gas or electric fire in a domestic environment. Dependent upon the particular product requirements and space available the compressor 1 and evaporator alternately heat exchanger 3 or heat exchanger 4 may be contained in the same integral unit with simple pipe 6 cOmmunications to an outside or air heat exchanger.

For example with regard to the half mounted arrangement 100 the parts of the modular heat pump and the flame effect generator provided by the visual panel will typically have a width of in the order of 400 mm and a height of in the order of 550 mm. The depth available into the half recess can vary from as little as 70 mm to as great as 300 mm. For similar application at least the flow heat exchanger 3 will be located within the recess whilst the compressor and one of the heat exchangers 4 is mounted externally typically away from the flow path. The pipe 6 will generally be flexible or semi rigid to allow ease of installation. Where the accommodation depth for the arrangement 100 is deeper then the modular heat pump can be more fully located within the cavity with less external pipe work to other parts of the modular heat exchanger.

By aspects of the present invention a stand alone heat pump is provided of a modular construction with the proportion in terms of parts of the modular construction of the heat pump located within the arrangement variable dependent upon accommodation space available.

It will be understood it is important that the visual panel 200 is of a limited depth in order.to ensure particularly with the shaUowest half recesses that there is adequate width for a flow path 201. In such circumstances it is necessary to use emulation technology in terms of projector 13, screen 15 and coals 14/101 that can achieve effeétiveness with regard to visual effects without requiring a significant depth for the illusion. Essentially the visible panel 200 hides the aesthetically unpleasing aspects of the heat pump and allows heat pump design to be completely free of any aesthetic considerations and therefore can achieve the highest level of operational efficiency.

Modifications and adaptations to aspects of the present invention will be appreciated by persons skilled in the technology. Thus, it will be understood that generally the visual panel in accordance with aspects of the present invention will provide little heating effect itself. Nevertheless, an interface surface between the visual panel and the fluid flow path 201 may be insulated to prevent heat exchange with the visual panel which could be to the detriment whether that be heating or cooling of the flow C along the flow path 201. Ideally for efficiency purposes all of the heating or cooling effect on the flow C should be presented through the outflow 0 with minimal heating of the S visual panel or for that matter other parts of the heating apparatus 100 in accordance with aspects of the present invention. Although provision of a heat pump as indicated above provides high efficiency with regard to operation it will also be understood for a boost effect an electrical resistance heater may be incorporated into the arrangement 100. As described above a fluid can be utilised within the flow path 201 in order to provide thermal mass.

This thermal mass may as indicated freeze water to form an ice block which can then be utilised to provide at least in a short term additional cooling effects beyond those of the heat exchanger 3 alone. Similarly, a fluid such as an oil may be heated by the heat exchanger 3 in order to provide heated I S thermal mass which again may add to the short term heating capability of the arrangement 100 to meet requirements. Additionally, ceramic blocks may be heated by the heat exchanger 3 in a similar fashionto eiectrical night storage heaters to provide additional thermal mass.

Claims

Claims 1. A heating arrangement comprising an insert assembly for an accommodation space, the insert assembly having a visible panel and a modular heat pump including a heat pump part hidden in a flow path extending behind the visible panel, the heat pump part comprising at least a flow heat exchanger and predetermined remaining parts of the modular heat pump including an external heat exchanger, a compressor and an expansion valve combined dependent upon accommodation within the flow path or externally away from the flow path to maintain a desired open cross sectional area for the flow path and a desired heat transfer between the flow heat exchanger and the external heat exchanger.
2. An arrangement as claimed in claim 1 wherein the flow path incorporates a fan or other means for stimulating flow.
3. An arrangement as claimed in claim I or claim 2 wherein the flow path extends from below the visible panel to above the visible panel.
4. An arrangement as claimed in any of claims 1, 2 or 3 wherein the flow path has an entry and/or exit defined by a grille.
5. An arrangement as claimed in any preceding claim wherein the visible panel comprises a screen to receive a visual projection in use.
6. An arrangement as claimed in claim 5 wherein the visual projection is of an active flame
7. An arrangement as claimed in any preceding claim wherein the visible panel incorporates elements to provide a solid fuel external appearance or pebble or fire logs.
8. An arrangement as claimed in any preceding claim wherein the flow path includes a liquid vessel to allow heat exchange to the liquid by the flow heat exchanger.
9. An arrangement as claimed in any preceding claim wherein the flow heat exchanger is elongate to extend along a proportion of the flow path.
10. An arrangement as claimed in any preceding claim wherein the flow heat exchanger is compressible and/or adjustable in terms of width for accommodation within the flow path.
11. An arrangement as claimed in any preceding claim wherein the flow heat exchanger and the external heat exchanger can be configured alternately as a condenser or evaporator within the modular heat pump.
12. An arrangement as claimed in any preceding claim wherein the modular heat pump comprises components of units sized to allow assembly of a number of such components dependent upon the available dimensions of the flow path.
13. An arrangement as claimed in any preceding claim wherein the arrangement incorporates an integrated cabinet to present the visual panel and the flow path.
14. An arrangement as claimed in claim 13 wherein the integral panel is arranged to extend into a recess in use.
15. An arrangement as claimed in any preceding claim wherein the flow path is defined between a rear portion of the visible panel and an opposite part of a recess within which the heating arrangement is located.16.. An arrangement as claimed in any preceding claim wherein the recess is specifically formed in a wall to receive the arrangement.17. An arrangement as claimed in any preceding claim wherein the compressor of the modular heat pump is driven by an electrical motor.18. A heating arrangement substantially as hereinbefore described with reference to the accompanying drawings.