Home | Business News | Browse by Publication | H | HVAC & R Research

Thermal response of the concrete slab of an indoor ice rink (RP-1289).

Article Excerpt
INTRODUCTION

In Canada, thousands of indoor ice skating rinks are used for sports (e.g., hockey, free skating, speed skating, or figure skating) and on occasion as auditoriums. They are often used 18 hours per day, seven days a week, eleven months each year. Because the ice sheet cooling load has a large ice surface area of 1000 to 2300 [m.sup.2] (10,760 to 24,750 [ft.sup.2]) (ASHRAE 1998), it requires a great deal of energy to remain frozen. The simulation of energy performance of ice rinks can help designers and energy auditors to reduce the annual energy use without negatively affecting the ice quality. The component-based simulation of the energy performance of refrigeration systems requires mathematical models for several components including chillers, heat exchangers, the ice sheet cooling load, and the concrete slab.

A review of literature on the subject reveals limited information regarding the mathematical models of heat transfer in the concrete slab of an indoor ice rink. Brown and Pearson (1986) developed a mathematical model to determine the effects of the brine pipe diameter, pipe pitch, ice sheet thickness, concrete thickness and pipe position in the concrete slab on the surface ice temperature variation, and the required refrigerant temperature for various surface temperatures. Jung and Krarti (2007) evaluated, by using an experimental setup, the ice refrigeration load for four different under-floor thermal insulations, which are installed to prevent heat gains from the ground. Patil et al. (2006) analyzed the thermal storage under the concrete slab of an ice rink by using the COMSOL Multiphysics (2005) environment.

This paper presents two mathematical models for the thermal response of concrete slab. The models predict the brine temperature leaving the concrete slab and returning to the evaporator of the refrigeration system in terms of variables that can be measured in the refrigeration system: the brine temperature leaving the evaporator and entering in the concrete slab and the ice temperature (Teyssedou 2007). These models can be used either for the simulation of the refrigeration system, for instance, connected with other models in the TRNSYS environment (SEL 2006), or for the control of the refrigeration system.

MEASUREMENTS

The two mathematical models developed in this study were calibrated and verified with measurements collected at the Camillien-Houde indoor ice rink in downtown Montreal (by CTEC-CANMET-Varennes). Financial support was provided by NSERC-Strategic Project 306792 (Galanis et al. 2004) and ASHRAE RP-1289 (Sunye et al. 2006, Ouzanne et al. 2006). The arena was constructed in the early 1980s with an ice surface of 61 x 26 m (203 x 87 ft). The refrigeration system includes two chillers that operate with refrigerant R-22 and are connected in series on the brine side. Each chiller has three semihermetic reciprocating compressors that are connected in parallel on the direct expansion evaporators. Each compressor has a capacity of 53 kW of refrigeration (15 tons) and is connected to an air-cooled condenser located on the roof of the building. The system operates from 3:00 to 24:00.

The Camillien-Houde arena was equipped with sensors and data loggers to collect information on the operating conditions of its refrigeration system. The long-term measurements were collected using permanently installed sensors at one-minute intervals over several days of different months. Data were then transferred to a computer through an Internet connection for storage and analysis. The short-term measurements were recorded using portable instruments. These measurements were performed with five compressors in operation, outside the regular hours of use of the ice. The refrigerant volumetric volume flow of liquid was measured as 0.287 l/s (4.55 gpm), equivalent to a mass flow rate of 0.3348 kg/s (0.738 lb/s), while the brine volumetric volume flow rate was measured as 27.75 l/s (439.9 gpm), equivalent to a mass flow rate of 34.324 kg/s (75.67 lb/s).

Figure 1 presents the power input to the refrigeration system, the ice temperature, and the brine temperature at the...

View this article FREE - Now for a Limited Time, try Goliath Business News
Free for 3 Days!