Source:JASE-W Japanese Smart Energy Products & Technologies

https://www.jase-w.eccj.or.jp/technologies/index.html

Keywords

Y4system or software

Z4

electricity

F33

electricity

Tokyo Electric Power Company Holdings, Incorporated

High-efficiency Heat Supply System (Unused Energy Utilization and Heat Recovery Heat Pump)
Features
Temperature difference of river water, sea water, sewage
water (treated or untreated), etc. is one of the unusedenergy sources. Because these waters are comparatively
warm in winter and cold in summer, they can increase theoperating efficiency of heat pumps.
When both types of load of cold heat and hot heatcoexist, heat recovery heat pumps that cansimultaneously produce cold water and hot water may beutilized for realizing high efficiency.
In both unused energy utilization and heat recovery heatpump, it is more rational to use thermal storage tanks in
combination with them and construct the overall system
as a thermal storage heat pump system that can offset
the time difference between heat supply and demand.
Introduced here is a case of a heat supply system thatuses treated sewage water as a heat source (MakuhariNew City High-tech & Business District).

Heat energy
Heat exchanger(Condenser)

Electric energy

Treatedsewagewater

HeatingCompressor
Electric motor
Pressur iza tion

De compressi on

Heat energy

Decompression
valve

Heat exchanger(Evaporator)

ColdwaterHeatcollection

Configuration of a heat pump system for using
treated sewage water (when cooling in summer)

To cooling tower
40[°C] 3 5Heat recovery heat pump

3025201510

Hotwater tank5

Coldwater tank0
Heat exchanger-556Max. airtemperature

Features of a system for using treated sewage water- The water intake line is equipped with an auto filter
for removing floating debris, etc. The heat exchange
tube of the heat pump is equipped with a brush-type
cleaning device for preventing the heat exchange
efficiency from being lowered by the accretion in thetube.
Operating state of heat source devices- Treated sewage water heat pumps and heatrecovery heat pumps cover around 60% and 40% of
the annual air conditioning load respectively.

89Min. airtemperature

1011121Max. treated sewage
water temperature

234[ Month ]Min. treated sewage
water temperature

Changes in outdoor air temperature and treatedsewage water temperature (May 2006 to April 2007)

System image for using a heat recovery heat pump

Basic Concept or Summar y7

Coolingtower

Treated sewage waterDB

Turborefrigerator

HP
Customers

O-24

HP

Sewage water HP (cold water)
Sewage water HP(hot water)
Heat recovery HP(cold water)
Heat recovery HP(hot water)
Turbo (cold water)

Hot water tankCold water tank

HP --- Heat pump that uses treated sewage water as a heat source
DB --- Heat recovery heat pump
Tube washing brush

Treatedsewage water

Auto filter

Annual heat production ratio byeach type of heat source machinery

Heat exchange tube in heat pump

Brush-type tube washing device

Plant system diagram (in summer) andtreated sewage water intake system

Effects or Remar ksO-24

Unused energy and heat recovery pumps are effectively utilized for realizing the first-rate efficiency
among the heat supply districts within the service area of TEPCO.

Overall energy efficiency

Makuhari New City High-tech& Business District: Unused energy utilization district(River water, groundwater, treated sewage water)

DHC mainly by electricity
0.60~1.26
Co-generation waste heatutilization method
0.68~0.87
DHC mainly by gas
0.36~1.73(Remark)ï Sites where co-generation
systems are installed inplants are excluded.
ï Overall energy efficiency =Heat sales / Amount of feed
fuel used
Source:Prepared based on Heat
Supply Business Handbook
2007 (data is for 2006).

Heat sales (G.J)

Overall energy efficiency of DHC districts within the service area of TEPCO

Experimental calculation of theeffect on reducing the amount of
CO2 emissions indicates CO2
was reduced by approximately
10,000 tons.

CO2Reduced by(Remark)approx. 50%
The national average DHC coefficient(approx. 10,000 t-CO2)of the amount of CO2 emissions perunit heat sales was compared withthe performance at the Makuhari New
City High-tech & Business District
Heat pump for utilizing sewage water heatand the effect was calculated using
Result of experimental
the annual heat sales of the said
calculation of the effect on reducing CO2District.

As the operation of a cooling tower is eliminated, water consumption is saved by around annual 120,000tons.
In Japan, the Tax Scheme for Promoting Investment in the Reform of Energy Supply-Demand Structure(Energy Reform Tax Scheme) is applied.
Awards received:
ï The 32nd Society of Heating, Air Conditioning and Sanitary Engineering Award (May 17, 1994 from The
Society of Heating, Air Conditioning and Sanitary Engineering);ï Global Warming Prevention - Minister of the Environment Award for Promulgation and Introduction ofCountermeasures Technology (Dec. 7, 2003 from Yuriko Koike, Minister of the Environment)

Installation in Practice or Schedule
Domestic

The cases of heat supply utilizing the unused temperature-difference energy:(1) Sewage water (treated or untreated) and gray water (domestic wastewater): 6 districts; (2)River water: 4 districts; (3) Sea water: 4 districts; (4) Groundwater: 3 districts.
Heat recovery heat pump (for simultaneous use of hot and cold water): Around 300 units.

Contact:

Tokyo Electric Power Company Holdings, Incorporated
www.tepco.co.jp