Publication detail

Enhancing the efficiency of a steam jet ejector chiller for chilled ceiling

KRAJČÍK, M. ŠTRBA, D. MASARYK, M. ŠIKULA, O. MLYNÁR, P.

Original Title

Enhancing the efficiency of a steam jet ejector chiller for chilled ceiling

Type

journal article in Web of Science

Language

English

Original Abstract

Steam jet ejector chillers (SJECs) can be a suitable cooling technology in buildings where solar heat gains constitute a significant part of the cooling load. In this study, an SJEC was combined with a radiant chilled ceiling (CC) instead of traditionally used convective cooling terminals in an effort to increase the coefficient of performance (COP) by increasing the supply water temperature to the terminal (T-water,T-sup) and thus the evaporation temperature. Experiments were used to verify a mathematical model of SJEC. The model was combined with T-water,T- sup obtained from heat transfer calculations in three types of CC performed by a verified software. The COP of the ejector cooling system was 0.25 and 0.38 for R718 (water) and R1233zd, respectively, at a generation temperature of 130 degrees C and T-water,T- sup of 7 degrees C, assuming a fancoil. Increasing T-water,T- sup to 9 degrees C, which was considered to be the lowest T-water,T- sup theoretically possible for CC involving pipes underneath the surface, improved COP by up to 14% while providing a maximum cooling capacity of about 80 W per m(2) of room area. Further increasing T-water,T- sup to 15 degrees C improved the COP by 50% compared to the fancoil, while covering cooling loads of at least 40 W per m(2). The estimated reduction in generation temperatures due to increased COP was up to 12% (T-water,T- sup = 9 degrees C) and 37% (T-water,T- sup = 15 degrees C). This means a lower energy input needed for the cooling machine, which allows a smaller solar collector area.

Keywords

Radiant cooling; Chilled ceiling; Ejector chiller; Ejector cooling system; COP; Buildings

Authors

KRAJČÍK, M.; ŠTRBA, D.; MASARYK, M.; ŠIKULA, O.; MLYNÁR, P.

Released

5. 7. 2022

Publisher

PERGAMON-ELSEVIER SCIENCE LTD

Location

OXFORD

ISBN

1359-4311

Periodical

Applied Thermal Engineering

Year of study

211

State

United Kingdom of Great Britain and Northern Ireland

Pages from

1

Pages to

15

Pages count

15

URL

https://www-sciencedirect-com.ezproxy.lib.vutbr.cz/science/article/pii/S1359431122004665

BibTex

@article{BUT178307,
  author="Michal {Krajčík} and Dominik {Štrba} and Michal {Masaryk} and Ondřej {Šikula} and Peter {Mlynár}",
  title="Enhancing the efficiency of a steam jet ejector chiller for chilled ceiling",
  journal="Applied Thermal Engineering",
  year="2022",
  volume="211",
  number="0",
  pages="1--15",
  doi="10.1016/j.applthermaleng.2022.118512",
  issn="1359-4311",
  url="https://www-sciencedirect-com.ezproxy.lib.vutbr.cz/science/article/pii/S1359431122004665"
}