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Värmemängdmätning för fjärrvärmenät, kombinerat med reglering av flöde och differenstemperatur

Engström, P. (1986) In MSc Theses
Department of Automatic Control
Abstract
In this report heat quantity measuring and temperature regulation of smaller heating networks have been studied. At lower flows, as well as at lower difference temperatures, the accuracy of the measurement is very low. Today's control of a heating plant endeavour to let the temperature of the water into the heating network follow the heat requirement. This control strategy leads to small heat losses in the network. It also leads to very low difference temperatures when the heat requirement is low (in the summer half). The low difference temperature implicates a debiting error between 3.20%, usually too low. <br><br> The purpose of this work has been to replace the debiting and control units with one, combined unit. Then not only the... (More)
In this report heat quantity measuring and temperature regulation of smaller heating networks have been studied. At lower flows, as well as at lower difference temperatures, the accuracy of the measurement is very low. Today's control of a heating plant endeavour to let the temperature of the water into the heating network follow the heat requirement. This control strategy leads to small heat losses in the network. It also leads to very low difference temperatures when the heat requirement is low (in the summer half). The low difference temperature implicates a debiting error between 3.20%, usually too low. <br><br> The purpose of this work has been to replace the debiting and control units with one, combined unit. Then not only the forward temperature but also the difference temperature and the flow can be controlled. A higher accuracy then can be guaranteed, even though the heat requirement is low. To investigate some strategies a dynamical model of a heating network has been used. Simulations have shown that it's possible to find a new operating point, which leads to a more accurate debiting. A suggestion to a simple, combined debiter-controller is presented. The suggestion has been implemented in a PC-system, ASEA Masterpiece 260. In purpose to verify the theories practically, the PC-system has been installed in a small heating plant. The new control strategy turned out to be very good. The debiting error could be reduced with almost 5%. For a more precise estimation of how much a heat producer can recover, further tests must be done. (Less)
Please use this url to cite or link to this publication:
author
Engström, P.
supervisor
organization
year
type
H3 - Professional qualifications (4 Years - )
subject
publication/series
MSc Theses
report number
TFRT-5345
ISSN
0280-5316
language
Swedish
id
8849580
date added to LUP
2016-03-27 17:15:22
date last changed
2016-03-27 17:15:22
@misc{8849580,
  abstract     = {In this report heat quantity measuring and temperature regulation of smaller heating networks have been studied. At lower flows, as well as at lower difference temperatures, the accuracy of the measurement is very low. Today's control of a heating plant endeavour to let the temperature of the water into the heating network follow the heat requirement. This control strategy leads to small heat losses in the network. It also leads to very low difference temperatures when the heat requirement is low (in the summer half). The low difference temperature implicates a debiting error between 3.20%, usually too low. <br><br> The purpose of this work has been to replace the debiting and control units with one, combined unit. Then not only the forward temperature but also the difference temperature and the flow can be controlled. A higher accuracy then can be guaranteed, even though the heat requirement is low. To investigate some strategies a dynamical model of a heating network has been used. Simulations have shown that it's possible to find a new operating point, which leads to a more accurate debiting. A suggestion to a simple, combined debiter-controller is presented. The suggestion has been implemented in a PC-system, ASEA Masterpiece 260. In purpose to verify the theories practically, the PC-system has been installed in a small heating plant. The new control strategy turned out to be very good. The debiting error could be reduced with almost 5%. For a more precise estimation of how much a heat producer can recover, further tests must be done.},
  author       = {Engström, P.},
  issn         = {0280-5316},
  language     = {swe},
  note         = {Student Paper},
  series       = {MSc Theses},
  title        = {Värmemängdmätning för fjärrvärmenät, kombinerat med reglering av flöde och differenstemperatur},
  year         = {1986},
}