HomeMy WebLinkAboutClark's Point Waste Heat Status Reports, Trip Reports 1990TRIP REPORT
TO: David Denig-Chakroff
Director, Rural Programs
FROM: John R. Bulkow
Rural Systems Engineer
SUBJECT: Trip Report
Manokotak, Clark’s Point, & Levelock
DATE: February 20, 1990
PURPOSE
The Alaska Energy Authority has agreements with the
Southwest Region School District and the Lake & Peninsula
School District to assist in the design and construction of waste heat systems in Manokotak & Clark’s Point and the
redesign of the waste heat system in Levelock. This trip was made to obtain the required design information at all three sites.
MANOKOTAK
I left Anchorage on the morning of February 5 and travelled through Dillingham to Manokotak via Markair & Markair
Express. On arrival in Manokotak I went directly to the school where I met with the principal, Kevin Hoyer. Mr. Hoyer indicated that the heating system of the school had
recently been rebuilt and was working well.
I then spent a few hours photographing and making as-built
sketches of the school boiler room and fan room. There is
ample room for waste heat recovery equipment in the boiler
room. The return header of the school heating system
already has valved and capped tees in place for future
connection of a waste heat system.
Next the power plant operator was contacted. He provided access to the powerhouse but did not have time to discuss connecting a waste heat recovery system. The powerhouse is
an approximately 16’x50’ uninsulated wood frame structure with metal siding and a concrete floor. The building contains three 300 KW generators. At the time of my visit
only one of the units was operating and one of the units was
partially dismantled (presumably for repairs). Each
generator set currently has a skid mounted radiator.
Connecting a waste heat recovery system would require
removing the skid mounted radiators and providing remote
radiators, a heat exchanger, & header piping connecting the
existing generator units to the new equipment. There is
sufficient space inside the powerhouse for a waste heat
recovery heat exchanger and space behind the powerhouse for
remote radiators.
After completing my inspection of the power plant I
investigated the area between the school and the powerhouse
for possible routes for the waste heat arctic piping. There are two logical routes for the piping to take. One route
could follow the existing roadway easements. A more direct
route would require obtaining a right-of-way across what
appears to be private property.
At 4:45 p.m. I took a Markair Express flight back to
Dillingham where I spent the night at the Bristol Inn.
The next morning I met with Don Ford, the maintenance
supervisor for the Southwest Region School District. Mr.
Ford took me to the school district maintenance building
where I reviewed the Fryer/Pressley design for the Manokotak school heating renovation. Together with one of the school
district welders we discussed Southwest Region School
District criteria for waste heat recovery systems. In
general they like our standard waste heat designs, however,
rather than tying the arctic pipe directly to the school
heating system as we sometimes do they would prefer to
isolate the school heating system from the arctic piping with a heat exchanger. At this meeting they also indicated
that they were down to about 400 ft of arctic pipe and completely out of arctic pipe fittings, foam packs, foam
pads, etc.
CLARK’S POINT
At 11:00 a.m. Don Ford & I took a Peninsula Air flight to Clark’s Point. We first checked in with Richard (Dick)
Montgomery, the school principal, and then went to the power
plant. Sam Clark, the power plant operator, met us there. Don Ford spoke with Sam Clark in the plant office while I
photographed and made as-built sketches of the generator
cooling system. The plant has three generator sets: a 50
KW, a 60 KW, & a 100 KW. Sam Clark indicated that power is
provided almost exclusively by the 60 KW unit. The
generator engines at this site have already been connected
to a common header and a remote radiator. Three unit
heaters for heating the powerhouse are connected directly to
the header and a shell & tube type heat exchanger was
incorporated into the system for future connection of a
waste heat recovery system. The system appears to function
adequately despite the fact that in some places the cooling
piping reduces in size for no apparent reason. Connecting a
waste heat recovery system for the school would require a plate & frame type heat exchanger and replacing the undersized piping in the cooling system.
After breaking for lunch we next inspected the school boiler room, fan room, and crawl space. The boiler room is congested and has little space available for a waste heat recovery heat exchanger. Capped tees terminating in the crawl space are already installed in the heating system
return header for connection of a waste heat recovery system. Unfortunately, one of these tees is incorrectly placed to be utilized. The most viable location for a waste heat recovery heat exchanger is in the fan room located directly above the boiler room.
At 4:00 p.m. Don Ford and I returned to Dillingham.
LEVELOCK
On the morning of February 7 I proceeded to Levelock via Peninsula Air. Chuck Beatie, maintenance supervisor for the Lake & Peninsula School District, met me at the airport and took me to the school.
As noted by Peter Hansen on a previous visit to this site, the school boiler room piping is quite complicated. There are certainly more pumps than necessary for this type of system and some of these pumps may be oversized. Chuck Beatie indicated that he would like the system redesign to simplify the piping as much as possible. Chuck Beatie also indicated that he liked the Grundfos series 200 type pump but would rather not use the dual head version of this model. It should be noted that there are two domestic water lines in the boiler room that are insulated with asbestos insulation. The School District is aware of the asbestos problem and has the area posted. Care should be taken, however, to avoid disturbing this piping while working on the heating system piping.
The power plant has three generator sets: two 130 KW units and a 50 KW unit. The 50 KW unit and one of the 130 KW units are connected to a common header. The piping of this common header runs through a shell and tube type heat exchanger, an AMOT valve, and then either back to the engines or through a remote radiator and back to the engines (depending on the operating position of the AMOT). Cooling piping for the third generator set is identical to the common header except there are no connections to the 50 KW unit. The two shell and tube heat exchangers capture the waste heat for the school. There are 2-way control valves in the secondary side piping coming from the heat exchangers. It appears that these 2-way valves shut when a temperature switch in the primary piping senses that the supply temperature from the engines has dropped below 145
degrees Fahrenheit. This protects the engines from being
overcooled but leaves the waste heat pump trying to pump
fluid through a blocked line when the valves close. No
controls for the remote radiators were evident, apparently
the remote radiator fan of whichever radiator is connected
to the running generator set is allowed to run continuously.
Work that should be done in the power plant includes
replacing the two shell & tube type heat exchangers with a single plate & frame heat exchanger, replacing the 2-way
control valves with a 3-way control valve, and providing two
speed controllers for the remote radiators.
At 5:45 p.m. I returned via Peninsula Air to Dillingham
where I took a Markair flight back to Anchorage.
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