The invention relates to a central air-conditioning system for mine excavations, in particular for cooling mine excavations in mines.

Polish patent no. PL203181 describes a system for climate control in mine excavations comprising a surface climate station connected with mine face coolers via a triple chamber pressure lock, which according to the invention is characteristic in that the said climate station equipped with at least one cooling tower is connected in a closed system by means of a feeder pipeline and a return pipeline with a triple chamber pressure lock, which in turn is connected by means of an over-level cooling pipeline with mine face coolers situated above the pressure lock and by means of a sublevel cooling pipeline with mine face coolers situated below the pressure lock, wherein the outlets of the mine face coolers are connected with the pressure lock by means of return pipelines via suction pumps.

In one embodiment of the invention according to patent no. PL203181 the system for climate control in mine excavations comprising a surface climate station connected with mine face coolers via a triple chamber pressure lock is characteristic in that the climate station equipped with at least one cooling tower is connected in a closed system by means of a feeder pipeline and a return pipeline with a triple chamber pressure lock, which in turn is connected via a force pump by means of an over-level cooling pipeline with mine face coolers situated above the pressure lock and by means of a sublevel cooling pipeline with mine face coolers situated below the pressure lock, wherein the outlets of the mine face coolers are connected by means of return pipelines with the open tank and with the pressure lock by means of the suction pump. The application description of patent application no. P- 390340 describes a central air-conditioning system for mine excavations comprising a surface climate station connected in a closed system with mine face coolers via a pressure exchanger, characteristic in that the said pressure exchanger is connected with the mine face coolers by means of the main cooling pipeline, wherein the outlets of the mine face coolers are connected with a cooling units assembly by means of return pipelines via an open tank and a pump system, whereas the cold water outlets of the cooling units assembly are connected by means of a pipeline with the cooling pipeline and the warm water outlets of the cooling units assembly are connected by means of an extra cooling pipeline with the return pipeline as well as with the pressure exchanger via an open tank and a pump system.

The aim of the invention is to use glycol or ice water in a high pressure cycle of an air-conditioning system by specific configuration of the elements of the system using plate-and-shell or counterflow plate pressure exchangers.

The central air-conditioning system for mine excavations comprising a surface climate station connected in a closed system with mine face coolers via a pressure exchanger according to the invention is characteristic in that it comprises a primary high pressure cycle equipped with at least two pressure exchangers connected in parallel with each other and a separate secondary low pressure cycle connected in a pump system with air coolers situated in exploitation sites.

Favorably, the system is equipped with three pressure exchangers connected in a secondary low pressure cycle with the cooling units assembly and air-coolers. Favorably, the pressure exchanger is a plate-and-shell pressure exchanger. Favorably, the pressure exchanger is a counterflow plate pressure exchanger. Favorably, the cooling medium in the primary high pressure cycle is glycol. Favorably, the cooling medium in the primary high pressure cycle is ice water. Favorably, in the secondary low pressure cycle in the return pipeline section between the pump system and the air coolers there is an inbuilt automatic filter and a rough filter.

Favorably, there are built-in cut-off valves in the main pipeline between the pressure exchangers and the air coolers.

Favorably, there is a built-in flow meter, a pressure meter and a temperature meter in the main pipeline between the pressure exchangers and the air coolers.

Favorably, in the primary high pressure cycle in the pipeline connecting the particular pressure exchangers there are built-in high pressure ball valves.

The main advantage of the invention is separating the primary high pressure cycle from the secondary low pressure cycle, which is possible as a result of using new types of pressure exchangers: plate-and-shell and counterflow plate exchangers, which makes it possible to use glycol or ice water as a cooling medium in the primary high pressure cycle.

Additionally, using low-power pressure exchangers connected in parallel makes it possible to connect any number of them into the system and by means of the valve system to adjust the cooling power according to the current air- conditioning requirements. Moreover, the said exchangers require less space in the mine excavations as a result of being smaller compared to other known exchangers. One non-exclusive embodiment of the invention is shown in the figure in which:

fig 1 - presents a schematic diagram of the air-conditioning system for mine excavations for cooling power of up to 5 MW;

fig 2 - presents a schematic diagram of the air-conditioning system for mine excavations for cooling power of over 5 MW in connection with an air- conditioning assembly installation;

fig.3 - presents a diagram of a pressure exchanger with a primary high pressure cycle and a secondary low pressure cycle;

Embodiment I

A central air-conditioning system for mine excavations comprises a surface climate station 16, connected in a closed system via a pressure exchanger 3 of the plate-and-shell type with mine face coolers 4 The system comprises a primary high pressure cycle 1 equipped with two pressure exchangers 3 connected in parallel with each other and a separate secondary low pressure cycle 2 connected in a pump system 5 with air coolers 4 situated in exploitation sites. In the primary high pressure cycle 1 the cooling medium is glycol, binary ice or ice water. In the secondary low pressure cycle 2 the cooling medium is water. In the secondary low pressure cycle 2 in the section of the return pipeline 7a, between the pump system 5, and the air coolers 4 there is an inbuilt automatic filter 8 and a rough filter 9. In the main pipeline 7 between the pressure exchangers 3 and the air coolers 4 there are inbuilt cut-off valves 10. Additionally, in the main pipeline 7 between the pressure exchangers 3 and the air coolers 4 there is a built-in flow meter H, pressure meter VI and temperature meter 13. In the primary high pressure cycle 1 in the pipeline 14 connecting the pressure exchangers 3 there are built-in high pressure ball valves 15 enabling the use of one or two exchangers depending on the power demand. Embodiment II

A central air-conditioning system for mine excavations comprises a surface climate station 6 connected in a closed system via a pump system 17 with a pressure exchanger 3 of the counterflow plate type with mine face coolers 4. The system comprises a primary high pressure cycle 1 equipped with three pressure exchangers 3 connected in parallel with each other and a separate secondary low pressure cycle 2 connected in a pump system with a cooling units 6 assembly and air coolers 4 situated in exploitation sites. In the primary high pressure cycle 1 the cooling medium is ice water, glycol or binary ice. In the secondary low pressure cycle 2 the cooling medium is water. In the secondary low pressure cycle 2 in the section of the return pipeline 7a, between the pump system 5, and the cooling units 6 assembly and the air coolers 4 there are built-in automatic filters 8 and rough filters 9. In the main pipeline 7 between the pressure exchangers 3 and the air coolers 4 there are built-in cut-off valves 10, making it possible to control the cooling power depending on the current demand. In the main pipeline 7 between the pressure exchangers 3 and the cooling units 6 assembly there is a built-in flow meter H, pressure meter VI and temperature meter 1_3_. Additionally, in the return pipeline 7a, between the air coolers 4, and the cooling units 6 assembly there is a built-in flow meter H, pressure meter VI and a temperature meter 13. In the primary high pressure cycle 1 in the pipeline 14 connecting the pressure exchangers 3 there are built-in high pressure ball valves 15 making it possible to use one or two exchangers depending on the power demand.