Comparative efficiency of applying heat pumps within the system of disposal of the condensation heat of heat machines for heating ice arenas

The analysis of the application of two energy-efficient technologies for air heating of ice arenas is considered, such as the use of heat pumps and a system for partial utilization of heat of condensation of heat engines. The actual energy costs during the operation of two systems are studied, such as the consumption of heat and electricity from heat and power supply organizations, as well as the costs of modernization. The weaknesses and positive aspects of the studied systems for air heating of ice arenas are revealed. Comparison of the calculated data obtained as a result of calculations with the actual data obtained in the research institution in which the study is carried out. An example of actual effective modernization of existing engineering systems is shown, as a result of which the energy efficiency of existing systems is increased. Additionally, we have performed the calculation of reducing thermal pollution with introduction of the investigated systems.


Introduction
Currently, due to the constant increase in energy prices in the territory of the Russian Federation, the direction of energy conservation is actively developing, tasks are being set to reduce heating costs by introducing energyefficient solutions [1][2][3][4][5][6][7][8][9][10][11]. One of the most popular ways to use environmental energy (soil, water, air) is to use a heat pump (VT). The concept of the operation of the VT is based on the collection of low potential energy and its use, both for heating, ventilation, and for heating water for household needs [12].
In addition, in some cases, it is economically profitable for enterprises to upgrade existing technological equipment to increase the energy efficiency of engineering systems, which in most cases is selected with a margin [13,14]. One of these methods of energy saving is the utilization of heat generated during various technological processes, and the use of this heat energy for the needs of the consumer [15][16][17][18]. Currently, heat recovery and the use of renewable energy sources in microclimate systems are widely used in the air system heating [19][20][21].

Methods
The object of the study is the heating of ice arenas in St. Petersburg State University of Higher Education SSHR in figure skating ( Fig. 1) with a heat pump and an integrated system for the partial utilization of the heat of condensation of heat engines. The purpose of the work is to identify problems associated with the overexpenditure of energy spent on maintaining the microclimate in sports facilities with artificial freezing of the ice surface, and ways to solve them. The relevance of the issue is due to economic and environmental aspects. A general analysis of existing technologies and examples of the implementation of these technologies at sports facilities are carried out. New schemes for organizing heating and ways to reduce costs are proposed. The positive effect and design conditions for achieving energy conservation goals are described. Further ways of developing heating and ventilation systems are proposed.
The objective of the work is to determine an economically and energetically advantageous solution by carrying out appropriate calculations and measurements of the use of a heat pump and a system for utilizing the heat of condensation of heat machines for heating ice arenas [22].
In the work, an actual study of the use of a heat pump and the introduction of a system for utilizing the heat of condensation of heat engines during air heating of ice arenas were carried out (Fig. 2).

Equipment:
The institution in which the study is performed: SPB GBU SSHR Figure Skating In the institution where the study was conducted, before the implementation of the system for utilizing the heat of condensation of heat engines, the heating of ice arenas was divided into two stages − heating and − inter-heating. During the heating period, ice arenas were heated due to the heat supplied from the heat supply organization, and in the interheating due to the heat pump.
Currently, only the system for utilizing the heat of condensation of heat engines is constantly involved in the heating of ice arenas.

Results and Discussion
When using a heat pump, the cost of operating costs for 5 months will be 684 064 rubles.
When using only the heat recovery system of condensation of heat engines for the same period, the cost of operating costs will be 162049 rubles. (Fig. 4). As a result, when comparing operating costs during operation of a heat pump and a system for utilizing the heat of condensation of heat engines, a cost-effective solution in this study case is a system for utilizing the heat of condensation of heat engines, the savings over 5 months will amount to 684064-162049≈522015 rubles or 104403 rubles/month.
The above results indicate the calculated values determined by the formulas, actual measurements confirmed the indicated amounts of expenses, a comparison of which is shown in table 1.

Conclusions
The introduction of a system for partial utilization of condensation heat of refrigeration machines for heating ice arenas due to fan heaters showed the following savings: 1. If you refuse the heat supplied by the State Unitary Enterprise TEK for heating the heat carrier for ice arena fan heaters in favor of using the condensation heat recovery system of refrigeration machines, taking into account the costs of the actual implementation, we will save about 2 million rubles in year: