GB2457926A

GB2457926A - Apparatus and method for supplying heat extracted from a cooling operation

Info

Publication number: GB2457926A
Application number: GB0803714A
Authority: GB
Inventors: Paul Menzies
Original assignee: GEO BAR Ltd
Current assignee: GEO BAR Ltd
Priority date: 2008-02-28
Filing date: 2008-02-28
Publication date: 2009-09-02
Anticipated expiration: 2028-02-28
Also published as: GB2457926B; GB0803714D0

Abstract

A heat exchange system comprises a heat exchanger and thermal storage device 3 arranged to extract the heat generated by a cooling operation 1, such as a refrigeration system. The heat exchanger and thermal storage device are connected to at least one heat utilising device 5, where the heat extracted from the cooling operation is supplied to the heat utilising device. A heat dump 2 may be provided to release heat to the atmosphere. If insufficient heat is generated by the cooling operation, a heat pump (4, fig.3) may be used to provide the additional heat energy required. The heat utilising device may involve underfloor heating, central heating or hot water supply. Preferably, the heat utilising device is a heated seat, where the seat has means for enabling heated fluid to be circulated below the seating surface. The system is preferably used to provide heating for bar and restaurant outdoor areas such as smoking areas, and alfresco dining areas for drinking and eating and outside. Alternatively, the heat extracted from the cooling operation may be supplied to a heat engine (6, fig.4) to drive a mechanical appliance (7, fig.4), such as a generator (8, fig.5), which may power an electrical appliance (9, fig.5).

Description

IMPROVEMENTS IN HEAT EXCHANGE SYSTEMS

The invention relates to improvements in heat exchange systems, and in particular a heat exchange system which utilises waste energy from existing cooling units to provide heat/energy for use in other applications.

As a result of the smoking ban throughout Europe, there has been a recent growth in the number of outdoor smoking areas for bars and restaurants. There has also been an increase in demand for alfresco areas due to bars and restaurants trying to increase trade areas and accommodate the demand for drinking and eating outdoors.

The concern with the above has been how to provide heating for the outdoor areas. At present patio heaters and electric infrared (IR) heating units have been the preferred options, with the disadvantage of high running costs and an increase in the carbon footprint.

It has been noted, however, that all bars and restaurants use refrigeration, and often other types of cooling, units for their business, which generates heat. At present the heat generated by these units is dumped into the atmosphere via external heat dumps, heat transfer devices or other means.

In most prior art cooling systems a cooling unit is commonly cooled by pumping a liquid coolant (normally water or a mixture of water and glycol) around a closed loop between the cooling unit and an external heat dump or heat transfer device, as shown in Figure 1. The hot liquid from the cooling unit is cooled by the external heat dump / heat transfer device thereby removing heat energy, and then returned at a lower temperature to the cooling unit.

At present, there are no systems that actively recycle the heat output from cooling units using heat exchanger & thermal storage device to provide a useful source of energy, whether heat energy, mechanical or electrical.

The object of the present invention is to capture the waste energy from existing cooling systems and to use this energy for various applications, such as underfloor heating, hot water supply, interior and exterior space heating, bench/seat heating or other applications.

The invention therefore provides a heat exchange system comprising a heat exchanger and thermal storage device arranged to extract heat generated by a cooling operation, said heat exchanger and thermal storage device being connected to at least one heat utilising device by means for supplying heat or heat energy to the heat utilising device, wherein said heat exchanger and thermal storage device uses heat extracted from the cooling operation to supply heat or heat energy to the at least one heat utilising device.

A heat pump can be connected to the heat exchanger and thermal storage device in the event that not enough heat is generated by the cooling systems to meet the heat energy demand.

It is also possible to replace the refrigeration systems in place with a heat pump, as the heat pump is itself a cooling system.

A by-product of this solution is that the heat exchanger and thermal storage device may increase the efficiency of the refrigeration process and provide, for example, colder beer.

The invention, although primarily designed with bars and restaurants in mind, can be applied to any industry that uses refrigeration, such as supermarkets and manufacturing.

Within some industries that use refrigeration, it is possible to use the captured heat energy and convert it to a mechanical output by using a heat engine and thereafter, electrical output by use of a generator.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:-Figure 1 is a schematic representation of a prior art cooling system; Figures 2 to 3 are schematic representation of a heat exchange system according to the present invention; and Figures 4 to 7 are schematic representations of alternative embodiments of the present invention.

Referring to Figures 2 and 3, a heat exchange system according to the present invention comprises a heat exchanger and thermal storage device(3), connected to the hot outlet of one or more refrigeration or other cooling units (1) which act as a heat source, via a hot liquid or other fluid supply (A) of a first closed loop system (A,B) The heat exchanger and thermal storage device (3), optionally with a heat pump (4) as shown in Figure 3 is used to absorb the heat energy of the cooling unit (1), usually from a coolant in the form of air or a liquid, and to then cycle the coolant back to the cooling unit (1) at a lower temperature via the cold fluid return (B). The absorbed energy can then be used to provide an amplified temperature output.

The heat generated by the cooling unit (1) is absorbed by the heat exchanger and thermal storage device (3) and may be fed directly to one or more heating appliance(s) (5) Alternatively, if not enough heat is generated by the cooling systems, a heat pump (4) can be used to provide the additional heat energy required and supplied on demand to the heating appliance(s) (5) as shown in Figure 3. As a further alternative, the heat generated by the cooling unit (1) which is absorbed by the heat exchanger and thermal storage device (3) may be fed directly to a heat engine (6) as shown in Figure 4. The heat engine (6) converts the thermal energy from the heat input to provide a mechanical energy output to one or more mechanical appliances (7) Alternatively, the heat engine (6) is arranged to provide a mechanical energy output to a generator (8), which converts the mechanical energy to provide an electrical energy output to one or more electrical appliances (9), as shown in Figure 5.

In a modification of the system shown in Figure 4, heat energy from the heat exchanger and thermal storage device (3) may be further increased by use of a heat pump(4) and supplied on demand to the heat engine (6), which provides a mechanical energy output for mechanical appliances (7), as shown in Figure 6, or a mechanical energy output to a generator (8) , which provides an electrical energy output for electrical appliances (9), as shown in Figure 7.

The heat exchanger and thermal storage device(3)is usually heated by the refrigeration systems (1), but not exclusively by it. The heat exchanger and thermal storage device (3) acts as a thermal store and the buffer tank.

The thermal storage device provides the facility to connect a hot water supply to various heating applications (5), e.g. underfloor heating, central heating, hot water supply, space heating, seat/bench heating or a heat engine.

A heat dump (2), which releases heat to the atmosphere, is optionally connected to the closed loop system (A & B) to facilitate servicing or repair or prevent the heat exchanger and thermal storage device(3) from over heating. The heat dump (2) may be an external dump or a heat transfer device. Valves are fitted to the closed loop system (A,B) to provide this functionality. This allows an option for the system to be shut off from the existing refrigeration closed loop system, if so desired.

The heat exchanger and thermal storage device (3) is connected in another closed loop system (C,D) to the various heating appliances (5) and/or a heat engine (6) . The closed loop system (C,D) comprises a hot liquid or other fluid supply (C) from the heat exchanger and thermal storage dev�ce(3) to various heating devices (5) and/or heat engine (6); and a cold liquid or other fluid return (D) from various heating applications (5) and/or thermal storage device (4) and/or heat engine (6) back to the heat exchanger and thermal storage device (3) Mains water may be connected to the heat exchanger and thermal storage device (3) via a cold liquid supply CE) to provide a hot water output (F), as shown in Figures 2 to 7.

The heat pump (4) may be connected to the heat exchanger and thermal storage device (3) of Figures 3, 6 and 7 by means of a further closed loop system (G,H) . The closed loop system (G,H) comprises a hot liquid or other fluid output (G) from the heat pump(4) to heat heat exchanger and thermal storage device(3) and a cold liquid or other fluid return (H) back to the heat pump (4) from the heat exchanger and thermal storage device(3) The heat engine (6) , may be connected to the generator (8) and/or mechanical appliances (7) of Figures 5 to 7 by means of a mechanical output (I) . The mechanical appliances (7) may be any devices which are operable using a mechanical energy input. The generator (8) is used where mechanical energy is received to be converted to electrical energy via electrical output (J) from generator (8).

The generator (8) may be connected to various electrical appliances (9) (Figures 5 and 7) which comprise any devices that can be operated using various forms of electrical energy input, which includes devices which feed the national grid.

Further arrangements are shown in Figures 8 & 9 having different combinations of cold and hot water supply/return (E,F) to/from the further arrangements (3) ; a combined supply/return (G,H) from the heat exchanger and thermal storage device (3) and heat pump (4) to heating appliance(s) and a heat engine (6) which are also linked to each other; and a combined output (I) from the heat engine to both mechanical appliances (7) and a generator (8) In a further embodiment of the invention, the heating appliance (5) may be a seat, for example a bench, which incorporates pipes or channels that allow hot water to be passed through just below the surface providing a source of heat energy to the seats surface/s. This enables heat to be provided direct to a person sitting on the bench, thus requiring less energy and a more immediate effect.

A system of valves may be used to enable the heat exchange system to be closed off from the cooling unit. This can be done remotely or manually.