ARBaurial
Festival Hall Heat Pump, London, UK
Advertisement from "The Engineer" magazine. Then ...
The Sydney Morning Herald
9 August 1951
Heat In Thames Water To Warm Festival Hall
By A STAFF CORRESPONDENT IN LONDON
The grey Thames water swirling past the piers of Hungerford Bridge is soon to be used to heat the great Royal Festival Hall (capacity 3.500), standing nearby on the South Bank exhibition site.
The plant, which can be described as a giant refrigerator working in reverse, is known technically as a heat-pump. It was designed by the scientific staff of the Fuel and Power Ministry as part of its fuel-conservation programme, and tests indicate that it has a thermal efficiency in the region of 150 per cent. - which means that the heat generated exceeds by one half the amount of fuel used to produce it.
Although the possibilities of the heat-pump - in principle quite a simple device - have been known for nearly a century, this is the first attempt to prove on a large scale its commercial possibilities. The high cost of pioneering and of manufacturing the considerable number of working parts required in such a heating system, which has to be specially designed to the requirements of a building, has discouraged its development by commercial firms. However, the scientists and engineers associated with the Festival Hall project say that three months of experiment have proved its efficiency and have opened up practically unlimited commercial prospects for the system.
This achievement can perhaps best be evaluated in the light of Britain's critical fuel shortage, intensified in recent months by the added strain of rearmament. Against the 150 per cent, heat efficiency of the heat-pump, the efficiency of the millions of tons of coal burnt annually in the open grates is approximately 15 per cent.; and that of the huge amount of electricity consumed by electric fires is less than 30 per cent.
The heat-pump system contains the equivalent of the main parts of the mechanical refrigerator a condenser and evaporator containing a refrigerant, also a compressor. The difference is in the layout. In a refrigerator the evaporator is in the cabinet and cools it by absorbing heat and passing it by means of the refrigerant to the condenser outside, which dissipates it into the atmosphere. In the heat-pump system the process is reversed. The liquid refrigerant, which will boil at a low temperature and pressure, is circulated through this system by the compressor.
The river water, piped through the evaporator, is of sufficient temperature to make the liquid refrigerant boil and vapourise. The vapour then passes through the compressor, which builds it up to a maximum pressure of 285 pounds a square inch in the condenser. Under pressure it condenses at a temperature of 165 Fahrenheit and releases the heat it has gained from the river water. This heat is in turn absorbed by water circulating in another system of pipes leading from the condenser to the hall, where it is finally released. The refrigerant liquid returns to the evaporator through a valve which reduces the pressure, thus turning it back into vapour, and the cycle is set off again by the initial heat absorbed from the river water.
Two Rolls Royce Merlin en- gines, modified to run off the mains gas, supply power for the system. A waste-heat boiler transfers further heat, generated by the exhausts of both Merlins, to the water circulating in the hall.
But this is not the end of the story. By a simple adjustment of the heat-pump, the roles of the condenser and the evaporator can be reversed so as to cool the hall.
Festival Hall Heat Pump, London, UK
Advertisement from "The Engineer" magazine. Then ...
The Sydney Morning Herald
9 August 1951
Heat In Thames Water To Warm Festival Hall
By A STAFF CORRESPONDENT IN LONDON
The grey Thames water swirling past the piers of Hungerford Bridge is soon to be used to heat the great Royal Festival Hall (capacity 3.500), standing nearby on the South Bank exhibition site.
The plant, which can be described as a giant refrigerator working in reverse, is known technically as a heat-pump. It was designed by the scientific staff of the Fuel and Power Ministry as part of its fuel-conservation programme, and tests indicate that it has a thermal efficiency in the region of 150 per cent. - which means that the heat generated exceeds by one half the amount of fuel used to produce it.
Although the possibilities of the heat-pump - in principle quite a simple device - have been known for nearly a century, this is the first attempt to prove on a large scale its commercial possibilities. The high cost of pioneering and of manufacturing the considerable number of working parts required in such a heating system, which has to be specially designed to the requirements of a building, has discouraged its development by commercial firms. However, the scientists and engineers associated with the Festival Hall project say that three months of experiment have proved its efficiency and have opened up practically unlimited commercial prospects for the system.
This achievement can perhaps best be evaluated in the light of Britain's critical fuel shortage, intensified in recent months by the added strain of rearmament. Against the 150 per cent, heat efficiency of the heat-pump, the efficiency of the millions of tons of coal burnt annually in the open grates is approximately 15 per cent.; and that of the huge amount of electricity consumed by electric fires is less than 30 per cent.
The heat-pump system contains the equivalent of the main parts of the mechanical refrigerator a condenser and evaporator containing a refrigerant, also a compressor. The difference is in the layout. In a refrigerator the evaporator is in the cabinet and cools it by absorbing heat and passing it by means of the refrigerant to the condenser outside, which dissipates it into the atmosphere. In the heat-pump system the process is reversed. The liquid refrigerant, which will boil at a low temperature and pressure, is circulated through this system by the compressor.
The river water, piped through the evaporator, is of sufficient temperature to make the liquid refrigerant boil and vapourise. The vapour then passes through the compressor, which builds it up to a maximum pressure of 285 pounds a square inch in the condenser. Under pressure it condenses at a temperature of 165 Fahrenheit and releases the heat it has gained from the river water. This heat is in turn absorbed by water circulating in another system of pipes leading from the condenser to the hall, where it is finally released. The refrigerant liquid returns to the evaporator through a valve which reduces the pressure, thus turning it back into vapour, and the cycle is set off again by the initial heat absorbed from the river water.
Two Rolls Royce Merlin en- gines, modified to run off the mains gas, supply power for the system. A waste-heat boiler transfers further heat, generated by the exhausts of both Merlins, to the water circulating in the hall.
But this is not the end of the story. By a simple adjustment of the heat-pump, the roles of the condenser and the evaporator can be reversed so as to cool the hall.