GB2285499A - Glycol cooling systems - Google Patents

Abstract

A cooling system in which two or more glycol cooling coils (3A, B) are located in a water bath (2) to create an ice bank. Refrigeration systems (5A, B) cool glycol reservoirs (6A, B). The glycol coolant is then pumped around the respective circuit (7A, B) by a submersible centrifugal pump (8A, B). Two circuits are required to ensure reliability and an acceptable ice bank configuration. Alternatively, the glycol circuits could be used to provide air chilling in a cabinet used for storing articles such as bottles of beer or confectionery. <IMAGE>

Description

Glycol Remote Cooling Systems The present invention relates to remote cooling systems and more particularly, but not exclusively, to cooling systems used in cellars of public houses to cool beer or air chilling in cabinets.

Due to the space constraints and unacceptable heat generation in bar areas of a public house it is common place to locate the beer cooling system remote from these bar areas in or near to the cellar where the product is stored. Such cooling systems typically are of the ice bank type.

There is also a requirement to provide chilled display cabinets in bar areas or other point of sale positions. Again the environmental heat problems and noise of refrigeration systems is not generally ideal and may not be acceptable.

An ice bank cooler comprises a tank of water with evaporator coils of a refrigeration system arranged such that ice is deposited on them during operation to form an ice bank. Product coils are also located in the tank such that beer is cooled prior to dispense. The ice bank ensures the cooler has excess capacity during periods of high dispense load.

Normally, refrigerated remote systems use copper tube lines between the cooling system and evaporators which are filled with refrigerant gas. Thus, to install such systems specialist skills are required along with relatively large volumes of refrigerant gas.

Furthermore, there is a serious danger of environmental damage if the refrigerant gas leaks. Such leaks of refrigerant gas are difficult to detect.

It is an objective of the present invention to provide cooling systems that avoid the above problems and allows coolers to be located in the bar area.

In accordance with the present invention there is provided a cooling system comprising at least two coolant circuits located within a cooled volume arranged to cool the cooled volume, each coolant circuit including a refrigeration pack to cool the coolant and a coil within the cooled volume and control means such that coolant flow can be adjusted to optimise product chilling.

The cooled volume may be a water bath in which an ice bank is formed about the coolant circuit coils or, a chiller cabinet for display of beer bottles or confectionary.

Preferably, the coolant in each coolant circuit is circuited by a submersible centrifugal pump.

Preferably, the control means is either a simple service valve and/or a solenoid valve coupled to a thermostat to determine either water temperature or ice bank formation in the tank.

Preferably, the coolant is glycol or a glycol and water mixture.

Preferably, the refrigeration packs are located at a remote location from the cooled volume where they can run efficiently and not emitting heat into an undesirable area.

Preferably, the refrigeration packs are of different thermal capacity to allow a greater range of operational temperatures.

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 illustration of a first embodiment of the present invention included in a ice bank system; and Figure 2 is a schematic illustration of a second embodiment of the present invention in a cabinet.

Consider Figure 1, an ice bank tank 1 is filled with water 2 and has two glycol coils 3A and 3B.

Beverage product coils are inserted into the tank as cassettes located within the coils 3A, 3B. An ice bank is built in the tank 1 by passing very cold glycol or glycol/water coolant mixtures through the coils 3A, 3B.

Typically, a 65% water/35% glycol coolant mixture is used and a temperature of -15C. The glycol coolant mixture is chilled by respective glycol cooling packs 4A and 4B.

These glycol cooling packs 4A, 4B comprise a refrigeration system 5A, 5B to cool a glycol coolant reservoir 6A, 6B. The glycol coolant is pumped around respective glycol circuits 7A, 7B using submersible centrifugal pumps 8A, 8B. Thus, through heat exchange an ice bank is generated about each coil 3A, 3B. Each circuit 7A, 7B has a flow side and a return side.

The flow side of each glycol circuit has a solenoid valve 9A, 9B and a service valve 10A, lOB. The service valve 10A, lOB allows the respective glycol circuit 7A, 7B to be switched off. The solenoid valve 9A, 9B allows flow in its respective circuit to be controlled in order to maintain an optimum ice bank size. It will be appreciated that ice is not an ideal thermal conductor thus as the ice bank develops the thickness of ice increases and so the difficulty of heat exchange between the water 2 and coils 3A, 3B increases. Thus, flow of glycol coolant is slowed or stopped once the required ice bank is achieved using the solenoid valves 10A, 10B under the control of a controller (not shown) which determines ice bank size. Such determination may be through temperature, weight etc.Two glycol circuits are provided to ensure if one circuit should fail at least some form of ice bank will be generated. Thus, two or more glycol circuits with associated glycol refrigeration packs 4A, 4B provide reliability. Furthermore, such multi-coil systems allow sufficient and more even distribution of ice in the tank 1.

Figure 2 illustrates a second embodiment of the present invention in a cooler or chiller cabinet 11 situation. Two coolant circuits 17A, 17B operate in a similar manner to circuits 7A, 7B in Figure 1. However, these circuits 17A, 17B cool air within a cooled volume 12 through panels 13A, 13B.

The panels 13A, 13B are normally built into the walls of the cabinet 11 such that the volume 12 available for storage of bottles of beer etc is maximised.

There may be a fan arrangement (not shown) to circuit air within the cabinet 11 and ensure an equalization of air temperature throughout the cabinet 11.

As indicated above each ciruit 17A, 17B has a cooling pack 14A, 14B with a refrigeration system 15A, 15B, a reservoir of coolant 16A. 16B, a submersible pump 18A, 18B with flow and return pipes to the circuit 17A, 17B.

Flow of the coolant is regulated by solenoid valves 18A, 18B and service valves 20A, 20B. These valves are controlled by a controller (not shown).

As will be seen panel 13A, 13B are of differing sizes. Thus, the air temperature in the volume 12 can be more accurately controlled and a wider range of temperatures achieved. This control may also be achieved by altering the coolant flow through respective circuits 17A, 17B.

Furthermore, the rating or capacities of the refrigeration packs 15A, 15B can be different to cool the coolant such as glycol to differing degrees.

It will be understood that the present cooling system provides the following advantages: (1) No electrical wire connection between the cooling areas and the refrigeration packs. Thus, reducing potential electrical problems.

(2) Reduced refrigerant gas usage in the refrigeration packs.

(3) Reduced environmental noise.

(4) Reduced installation skill; and, (5) Better cooling and ice bank formation due to more steady heat transfer with a glycol coolant.

It will be appreciated that submersible centrifugal pumps are preferred as these pumps allow 'dead-end' operation. That is to say, the pump can still operate when coolant flow is stopped by the valves 9A, 9B. The glycol cooling packs 5A, 5B can be located in a cellar or near the cellar area whilst the tank 1 can be located either in that celler area or at another location such as under the counter of a bar.

Claims (9)

CLAIMS:

1. A cooling system comprising at least two coolant circuits located within a cooled volume arranged to cool the cooled volume, each coolant circuit including a refrigeration pack to cool the coolant and a coil within the cooled volume and control means such that coolant flow can be adjusted to optimise product chilling.

2. A cooling system as claimed in claim 1 wherein the cooled volume is a water bath in which an ice bank is formed about the coolant circuit coils.

3. A cooling system as claimed in claim 1 wherein the cooled volume is a chiller cabinet for display of beer bottles or confectionary.

4. A cooling system as claimed in claim 1, 2 or 3 wherein the coolant in each coolant circuit is pumped by a submersible centrifugal pump.

5. A cooling system as claimed in any proceeding claim wherein the control means is either a simple service valve and/or a solenoid valve coupled to a thermostat to determine either water temperature or ice bank formation in the tank.

6. A cooling system as claimed in any proceeding claim wherein the coolant is glycol or a glycol and water mixture.

7. A cooling system as claimed in any proceeding claim wherein the refrigeration packs are located at a remote location from the cooled volume.

8. A cooling system as claimed in any proceeding claim wherein the refrigeration packs are of different thermal capacity to allow a greater range of operational temperatures in the cooled volume.

9. A cooling system substantially as hereinbefore described with reference to either of the accompanying drawings.

9. A cooling system substantially as hereinbefore described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. A cooling system comprising at least two coolant circuits each partly located within a cooled volume and arranged to cool the cooled volume, at least one coolant circuit including a refrigeration pack remote from the cooled volume to cool the coolant, a coil or panel within the cooled volume forming part of the circuit and control means adjacent the cooled volume such that coolant flow to the coil or panel can be turned on or off in response to a signal indicative of the state or temperature of the cooled volume.

2. A cooling system as claimed in claim 1 wherein the cooled volume is a water bath in which an ice bank is formed about a coolant circuit coil.

3. A cooling system as claimed in claim 1 wherein the cooled volume is a chiller cabinet for display of beer bottles or confectionary.

4. A cooling system as claimed in claim 1, 2 or 3 wherein the coolant in each coolant circuit is pumped by a submersible centrifugal pump.

5. A cooling system as claimed in claim 2 or 4 in which the signal available to the control means is indicative of ice bank size.

6. A cooling system as claimed in claims 2, 4 or 5 wherein the control means is either a service valve and/or a solenoid valve coupled to a thermostat to determine either water temperature or ice bank formation in the tank.

7. A cooling system as claimed in any proceeding claim wherein the coolant is glycol or a glycol and water mixture.

8. A cooling system as claimed in any proceeding claim wherein the refrigeration packs are of different thermal capacity to allow a greater range of operational temperatures in the cooled volume.