Development and Sale of Heat Pump for Use in Cleaning Processes -Realization of High Efficiency in a Heat Pump for Heating Cleaning Liquids for Machine Components-
February 25, 2010
Chubu Electric Power Co.,Inc.
Chubu Electric (President: Toshio Mita; Head office: 1 Higashi-shincho, Higashi-ku, Nagoya City, Aichi Prefecture) and ZENERAL HEATPUMP INDUSTRY CO., Ltd. (President: Yoshitomi Shiba; Head office: 121 Mishinden Odakacho, Midori-ku, Nagoya City, Aichi Prefecture) have jointly developed a heat pump for use in machine part cleaning processes. Excellent results were obtained in field trials of the heat pump by Toyota Motor Corporation and AISIN AW CO., LTD., and it has therefore been decided to put the unit on the market.
The new heat pump will be marketed from March 2010 by Toyota Tsusho Corporation (President: Junzo Shimizu; Head office: 9-8 Meieki 4-chome, Nakamura-ku, Nagoya City, Aichi Prefecture).
Generally, the cleaning liquids used in the cleaning process that follows the cutting of machine parts in factories are heated to around 60°C using steam from a boiler. However, when the boiler room and the room in which the cleaning is carried out are widely separated in the grounds of the factory, heat loss from the steam pipes increases and thermal efficiency declines. For this reason, it would be desirable to position a high-efficiency heating device close to the cleaning process in order to conserve energy. However, until now, no heat pump for use in manufacturing processes that is able to provide high-efficiency heating to 60°C has been available.
Heat pump technology employing the optimal refrigerant for the heating of cleaning liquids has been employed in the developed product, enabling the realization at high efficiency of optimal circulation heating*1 (cleaning liquid temperature at inlet: 60°C; temperature at outlet: 65°C) for the heating of cleaning liquids. In addition, a filter has been employed for the heat exchanger to respond to the oil mist*2 produced in factory cutting processes, which is a cause of reduced efficiency in heat pumps. This enables the heat pump to be positioned close to the cleaning process (within the same room).
The line-up of the developed product features both a unit that functions exclusively as a heater and a unit that can be used for both cooling and heating*3. In addition to supplying hot water, this latter unit is simultaneously able to supply cold water at 15°C for use in cooling the liquid used in the cutting process, further increasing energy savings. Each type of unit is available in models with heating abilities of approximately 11 kW, 22 kW, and 43 kW, enabling customers to select the appropriate unit for the scale of their factory.
Main features of the newly developed product
1 Uses circulation heating to heat cleaning liquids
The system is able to realize high-efficiency circulation heating (cleaning liquid temperature at inlet: 60°C; cleaning liquid temperature at outlet: 65°C) in order to maintain the temperature of the cleaning liquid at 60°C.
2 Offers significant energy savings
The heating-only units achieve a COP of 3.0*4, and the heating and cooling units achieve a total COP of 5.2*5. Energy consumption, CO2 emissions, and running costs are reduced by 60-70%*6 against conventional systems using boilers and chillers.
3 Protection against oil mists in factories and increased convenience
A filter has been employed on the heat exchanger to protect the unit from oil mists in factories. In addition, convenience has been increased through the use of touch panel operation.
(*1) Circulation heating of cleaning liquids
The cleaning liquid that has been returned to the unit at a reduced temperature is reheated to enable it to be reused.
(*2) Oil mist
Oil and grease that floats in the air in the form of mists. In many cases cleaning processes are located next to cutting processes. The supply of cutting oil to lubricate the high-speed tools used in the cutting process results in oil mists. The adhesion of these oil mists to the air heat exchangers used in heat pumps results in a decline in efficiency.
(*3) The unit can be switched between three modes: Simultaneous cooling and heating, cooling only, or heating only. A unit is also available that operates only as a simultaneous cooler and heater.
(*4) Heating COP
Heating COP is defined as heating ability in kW divided by power consumption in kW. The higher this figure, the greater the energy saving. The COP of 3.0 for the heating-only units is the figure measured under conditions of an external dry bulb temperature of 25°C, an external wet bulb temperature of 21°C, and cleaning liquid temperatures of 60°C at the inlet of the developed product and 65°C at the outlet.
(*5) Total COP
Total COP is defined as the sum of heating ability in kW and cooling ability in kW, divided by power consumption in kW. Like heating COP, the higher this figure, the greater the energy saving. The total COP of 5.2 for the developed product was measured under conditions of cleaning liquid temperatures of 60°C on the unit inlet side and 65°C on the outlet side, and cold water temperatures of 20°C on the inlet side and 15°C on the outlet side.
(*6) Estimated figures are based on the results of field trials conducted at Toyota Motor Corporation and AISIN AW CO., LTD.
<Inquiries concerning these products>
ZENERAL HEATPUMP INDUSTRY CO., Ltd. (Development Division)
(Contact: Yoshiro Shiba TEL:+81-52-624-6368)
<Contact for sales inquiries>
Toyota Tsusho Corporation (Facilities Environment Group, Machinery & Electronics Division)
(Contact: Yu Kinoshita TEL:+81-52-584-5920)