Application of Water Source Heat Pumps on Ships

Reporter Ren Yong & Chen Shi

Theoretically, water source heat pumps can be applied on ships. However, some new problems emerge due to changes of operation environment.

The application of marine heat pumps includes heating application and refrigerating application. Compared with boiler systems, heat pumps are more efficient and energysaving. In addition, refrigerating capacity is also necessary on ships and heat pumps can also achieve the function of refrigerating. This “one system, two functions” can contribute to reducing equipment investment and ship tonnage.

As the leader of MIIT high-tech vessel scientific research project, CCS puts the water source heat pump system which is firstly researched by CCS on the cruises used for foreign affairs for the first time. It is proved that the heat pump systems are more efficient.

For example, No. 2 cruise is equipped with 3 refrigerating and heating water source pump units. Dehumidifying fan coils are installed as indoor units.

In summer, unit 1 and 2 provide cool water for air conditioning system and clean hot water. Unit 3 runs as a standby. Traditional marine water chilling unit + fuel exhaust boiler hot water system can be completely replaced.

In winter, according to hot water requirement, unit 1 and 2 supply hot water at the same time, and each unit is the backup for the other; unit 3 is used for heating; unit 2 is the backup for unit 3. Traditional fuel exhaust boiler heating systems and domestic hot water systems can be replaced.

Taking No. 2 cruise as an example, according to measurement, water source heating pump systems save 39.31% more fuel oil than original plan of water chilling unit + boiler in summer; this new technology saves 45.94% more fuel oil than water chilling unit + boiler in winter.Assuming that the system runs for 135 days in summer and 80 days in winter, 247.9 tons of fuel oil can be saved,which amounts 357 tons of standard coal. Carbon emission will be cut by 956.8 tons. The effect of energy saving and emission reduction is obvious.

In respect of investment costs, water source pump technology will not cost much more money than the plan of water chilling unit + boiler system. Based on current fuel price, cost can be recovered in 2 years.

At present, some countries have conducted lots of researches in energy-saving and emission-reduction field.Marine heating and refrigerating systems are fundamental guarantee to create humane environment onboard ships.Therefore, the marine water source heating pump system application research conducted by CCS will have obvious benefit in energy-saving and is of great prospective.