GB2480861A

GB2480861A - Refrigeration plant with multiple refrigeration units

Info

Publication number: GB2480861A
Application number: GB1009355A
Authority: GB
Inventors: Michael John Filmer
Original assignee: M F REFRIGERATION Ltd
Current assignee: M F REFRIGERATION Ltd
Priority date: 2010-06-04
Filing date: 2010-06-04
Publication date: 2011-12-07
Anticipated expiration: 2030-06-04
Also published as: GB201009355D0; GB2480861B

Abstract

A refrigeration system particularly suitable for beverage cooling has a plurality of self-contained and interchangeable refrigeration units 101, 101'. Each unit includes a refrigerant plant 102, a cooling heat exchanger 103 with an input 105 for liquid to be cooled and an output 106 for the cooled liquid. Piping connects the output from each refrigeration unit, and cooled liquid is conveyed to a cooling device, such as a cellar-cooling fan 109 or a beverage chill tank 110. The arrangement can include a thermostatic control unit 113 for the refrigeration units, and each unit can be disconnected and removed from the system. The arrangement can also include control of operational modes, a first mode in which all units are operational, a second mode in which none of the units are operational, and a third mode in which only some of the units are operational. In the event of a breakdown or for routine maintenance, some units can be removed while leaving other refrigeration units in use, so that the system does not have to be closed down in the event of failure or maintenance of one unit.

Description

I

REFRIGERATION PLANT

This invention relates to refrigeration apparatus, and especially to plant for cellar storage and beverage cooling. Premises on which drinks are served generally have a cellar or other room for cool storage, which may also contain one or more chill tanks from which cooled beverages can be piped directly to a dispensing point. One or more such chiller tanks, as well as a cooling fan or the like for reducing ambient temperature, may be fed cooled refrigerant from the same refrigerating plant. Such plant is generally subject to thermostatic control.

A problem that can arise with such systems is that in the event of a breakdown the entire refrigeration unit has to be removed from the premises for repair, leaving the premises without refrigeration, possibly for a prolonged period.

In accordance with a first aspect of the present invention, there is provided a refrigeration system comprising: a plurality of refrigeration units, each unit comprising refrigerant plant, a cooling heat exchanger, an input for liquid directed through the cooling heat exchanger and an output for conveying cooled liquid from the heat exchanger to a point of use; cooling means, such as a fan or chill tank, fed with cooled fluid by a common conduit connected to respective cooled liquid outlets from said plurality of refrigeration units; and a control unit for controlling the refrigeration units whereby there are three modes of operation depending on the difference between an actual and a desired temperature: one in which all refrigeration units are operative, one in which only some of the refrigeration units are operative and one in which none of the refrigeration units are operative.

The inventor has appreciated that by employing a plurality of relatively small refrigeration units whereby not all need be operative at once, efficiency savings can be realised.

In accordance with a second aspect of the invention, there is provided a refrigeration system comprising: a plurality of self-contained and interchangeable refrigeration units, each unit comprising a refrigerant plant, a cooling heat exchanger, an input for liquid to be cooled by said cooling heat exchanger, an output for liquid thus cooled, piping connected to the outputs from each said refrigeration unit for conveying liquid to a cooling device and a thermostatic control unit for said plurality of refrigeration units.

The refrigeration units are individually connectable to a common coolant supply to one or more cooling devices such as a fan or chill tank, and each refrigeration unit can be individually disconnected and removed from the system, leaving the other refrigeration unit or units in operation. Thus, if one unit breaks down it can be removed for repair while leaving a functioning refrigeration system in place. The system as a whole can be provided with enough refrigeration units to provide more than the usually required refrigeration capacity, so that the refrigeration units do not all need to operate at full power at any one time. When one refrigeration unit is removed for repair, it can if required be replaced by a spare unit. This means that the potentially complex maintenance of refrigeration plant made up of these units may be accomplished off stream, if necessary at the plant supplier's premises rather than that of the customer.

An exemplary embodiment of the invention will now be described with reference to the accompanying drawing which shows, schematically, a refrigeration system suitable for use on premises serving chilled beverages.

The apparatus illustrated in the drawing comprises a housing 100 in which are located two or more refrigeration units 101, 101', operating in parallel. These units are self-contained and replaceable and are preferably identical.

Each refrigerator may be of the compression type, using a fluid refrigerant such as R-404a, a mixture of Tn, tetra, and pentaflouroethanes. From a compressor the fluid passes through a condenser on the "hot" side of the system where it gives up heat to a heat exchanger 104, and then through an expansion valve to an evaporator on the "cold" side of the system, passing through a heat exchanger 103.

A liquid heat carrying medium such as water circulates through a heat disposal circuit 115, with a pump 116, connected to detachable inputs 107, 107' to the respective hot side heat exchangers of each refrigeration unit and detachable outputs 108, 108' from the same heat exchangers, to convey heat away from the system either for outside disposal or for some other use such as space heating.

On the cold side of the system, a coolant such as a water/ethylene glycol mixture circulates through a cooling circuit between the refrigeration units and cooling systems such as a fan 109 and a chill tank 110. This circuit has detachable inputs 105, 105' to respective cold side heat exchangers, 103, 103', and detachable outputs 106, 106' from the same heat exchangers. A pump 114 circulates the coolant through a heat exchanger 111 of space cooler 109, through which air is drawn by an electrically-driven fan 112, for example to cool a cellar in which beverages are stored.

Another branch of the circuit passes through a cooling coil of a chill tank 110, for example an ice bank cooler through which a beverage such as beer can be circulated to chill it to the desired temperature at which it can be piped through a "python" or similar system to a dispensing point.

The water/glycol mixture is fed from a reservoir 116 and can be cooled by the heat exchangers 103, 103' to a temperature of for example -2°C, so that the chiller tank can develop an ice bank and maintain the water in it close to 0°C, while the cellar cooling fan can maintain a cellar temperature of 8 to 10°C.

A thermostatic control unit 113 is provided for controlling the temperature to which the refrigeration units 102, 102' cool the circulating water/glycol mixture.

The fluid refrigerant will typically be at a temperature of about -10°C when passing through the cold side heat exchanger 103, cooling the water/glycol mixture to the required low temperature.

The precise temperature to which the water/glycol mixture is cooled will depend on the particular purposes to which it is being put, and can be controlled in response to the measured cellar temperature and the temperature of the chill tank 110. Each of the cooling systems being supplied can be isolated from the cooling circuit by suitably placed valves when they are not required. For example the cooling fan unit 109 might not be required during winter.

The refrigeration system may have three modes of operation, depending on the measured difference between an actual and a desired temperature in one of the environments being cooled, for example the cellar temperature. For example there may be one mode in which all refrigeration units 102, 102' etc are operative (e.g. when the measured temperature difference is 2°C or more), one in which only some of the refrigeration units are operative, (e.g. when the temperature difference is greater than 1°C but less than 2°C) and a third mode in which none of the refrigeration units are operative, when the actual temperature measured is within 1°C of the desired temperature.

If one of the refrigeration units 102, 102' breaks down or requires routine maintenance, it can be removed by detaching the coolant input and output leads 105, 106, 107, 108 and closing these off. It can if necessary then be removed from the premises for repair and may be replaced by a similar unit or the system may continue to operate with the remaining unit or units.

For increased efficiency, the system could be adopted to carry out routine maintenance in winter when the system can operate with fewer than its full tally of refrigeration units.

Claims

CLAIMS: 1. A refrigeration system comprising: a plurality of self-contained and interchangeable refrigeration units, each unit comprising a refrigerant plant, a cooling heat exchanger, in input for liquid to be cooled by said cooling heat exchanger, an output for liquid thus cooled, piping connected to said outputs from each said refrigeration unit to convey the cooled liquid to a cooling device and a thermostatic control unit for said plurality of refrigeration units.
2. A refrigeration system according to claim I wherein said self-contained refrigeration units are identical to one another.
3. A refrigeration system according to claim I or claim 2 wherein coolant circulating from the cold site heat exchangers is arranged to circulate through a heat exchanger of a cellar-cooling fan.
4. A refrigeration system according to and preceding claim wherein liquid coolant from said cold side heat exchangers is arranged to circulate through a beverage cooler.
5. A refrigeration system according to any preceding claim further comprising a heat disposal circuit wherein a liquid heat carrying medium is arranged to convey heat away from a hot side of the or each refrigeration unit in use.
6. A refrigeration unit comprising: a plurality of refrigeration units, each unit comprising a refrigerant plant, a cooling heat exchanger, an input for liquid directed through the cooling heat exchanger and an output for conveying cool liquid from the heat exchanger to a point of use; cooling means fed with cooled fluid by a common conduit connected to respective cooled liquid outlets from said plurality of refrigeration units; and a controlled unit for controlling the refrigeration units whereby there are three modes of operation depending on the difference between an actual and a desired temperature; one in which all refrigeration units are operative, one in which only some of the refrigeration units are operative and one in which none of the refrigeration units are operative.