SU1441075A1 - Method of controlling heat duty of underground structures - Google Patents

Abstract

The invention relates to mining n m. used for air conditioning in subterranean formations for various purposes. The purpose of the invention is to increase the efficiency of regulation of the thermal regime by using a substance that changes its state of aggregation to remove the heat of condensation. Cool the air with a coolant circulating between the evaporator of the chiller and the air cooler. The heat of condensation of the refrigerant is removed by cooling water, for which the latter is passed through a layer of elastic gas-tight capsules placed in the cavity. They are filled with a substance with a phase transformation t-equal to t-re cooling water after the condenser, and a phase transition heat determined from the ratio taking into account the specific heat capacity, the density of water and the substance filling the capsules, and also taking into account cooling water after the condenser and the initial cooling water cooling system filling the cavities. To restore the potential of the substance filling the capsules, they are cooled with water. The latter is previously passed through rocks with a temperature not exceeding the phase transformation of the substance. The use of the method allows to reduce the volume of cavities that serve to cool water, which leads to lower costs. 1 h, para. f-ly, 1 ill. (L

Description

01

The invention relates to mining and can be used for air conditioning in underground structures for various purposes.

1W.

The purpose of the invention is to increase the efficiency of regulation of the thermal regime.

The increase in the effectiveness of the regulation of the thermal regime of underground structures is achieved by the fact that the cooling water is passed through placed in the cavities in the cavity of elastic gas-impermeable capsules filled with a substance with a temperature of phase transformation equal to the temperature of the cooling water after the condenser.

The choice of the substance used to fill the capsules in each case depends on the type of refrigerant, its condensation temperature, the volume of the cavity and the required period of continuous operation of the refrigerating machine. In all cases, the storage capacity of a unit volume of a cavity filled with capsules with a substance must be higher than a unit volume of water. With the porosity of the layer of capsules, the heat capacities of water and substances C and Cg,} their density x pf: and the tag of the phase transition G f the temperature of the phase transition Td, tox And the initial cooling water temperature tg will be case

b

(1 -) (Sv - t

he

  P (1)

Solving inequality () relative to the value of G, we obtain

 l) (t 6P6

ox

t.)

The drawing shows one of the possible schemes for implementing the method of regulating the thermal regime of underground structures

The scheme includes an underground structure 1, an air cooler 2, a pump for circulating coolant 3, an evaporator of a refrigerating machine 4, a compressor 5, a condenser 6, a pump dp providing chiller cooling water 7 of a cavity 8, elastic gas-tight capsules with substance 9 e for cooling „

- | d fs

20 25 stars

45

supplying water 10, valves P and 12, channels 13, mountain 14, pumps for pumping water through channels in the mountain 15,

The method is carried out in the following manner.

The air moving through the underground structure 1 is cooled in the air cooler 2 as a result of heat exchange with the coolant, using a pump 3 circulating between the evaporator 4 and the air cooler 2, the heat taken from the air, in the evaporator 4 is transferred to the refrigerant, the vapors of which enter the compressor 5 , and from it into the condenser is white. The refrigerant vapor is vaporized when the valves 1 and 12 of the first cavity 8 are closed (the valves 11 and 12 of all the other cavities 8 are closed) is carried out with water circulating by means of a pump 7 0} of the conduit between the first cavity 8 filled elastichnymi- gastight capsule with substance 9, and the condenser 6 As a result, the pair of the refrigerant condensed in the resulting dross after ™ lation boiling liquid saturated wet steam enters the evaporator 4, where XJ7adonocitel off. The cooling water entering the condenser 6, has a temperature t In the process of heat exchange with refrigerant vapor, it heats up and with a temperature t enters the cavity 8 filled with capsules with substance 9, the phase transition temperature of which is also rat Tf ,, t. The result of heat transfer is ohla} to the water input. with substance contained in capsules 9 is its transition to a different aggregative state, accompanied by heat absorption and a decrease in water temperature to the initial temperature t. With this temperature, the cooling water again enters the condenser 6 "Functional time of unit poltexti volume V cooling water flow rate G. is

()

R

1 hm (t

uIto..rto i /: cBlC5 6l

:(,) J

55

„MVn 5;

(3)

When the time expires, the valves And in the first cavity 8 are closed,

31441075

and the valves 12 are uncoupled, and by means of the pump 15 a circulation of volos 1 is organized

dy with temperature t, between the first cavity 8 and the system of channels 13, made in the mountain massif 14 with temperature t. less than t

about

-Oh

15

20

25

By the process of moving along the channels 14, the water takes the temperature t and, falling into the cavity 8, cools the substance in the channels 9 to the temperature tj, bringing it to its original aggregative state. The recovery time of the working potential of the substance contained in the capsules 9 of the first cavity 8 corresponds approximately to the time f „

During the recovery period of the operating potential contained in the capsules 9 of the first cavity 8, the substance, the heat of condensation is removed by cooling water from the second cavity c. For this, the valves 11 are opened and the vent 15 is closed. Cavities III and IV are reserve and valves 11 and 15 are closed all this time.

Example. In the underground structure, a refrigerating machine with a cooling capacity of 28 kW is installed operating on a refrigerant Freon-12. The evaporating temperature of Freon is 12,278 K, the condensation temperature is 313 K. The ratio of the thermal power output in the condenser to the cooling capacity of the manshna is 1.13. The initial temperature of the cooling water is 298 K, and the temperature of the cooling water after the condenser is 308 K. The porosity of the layer of elastic gas-tight capsules filling the cavities is 0.45. The volume of the cavity is 50 m. The heat capacity and density of cooling water is C 4.19-10 J / kg, K, r 10 kg / m. It is necessary to make a choice of the substance for filling the capsules and establish the operating time of each cavity 2 p.

The heat load on the condenser of the refrigerating machine is determined.

Q 20-1.13 22.6 kW.

Calculate cooling flow rate

thirty

35

40

45

50

 (tox tfl)

22 6-10

47T9 To-To 308-298)

5.41

.

Using inequality (2), the necessary non-value of the heat of phase transition of a substance is determined. In this case, approximately take Cp 2.26. 10 / fe / kg K, pg 0.9-10 kg / m.

five

0

, 4.19-10 10

5.2.26., Or- || - |, -tg, -,). 4308-298) 19.3-10 J / kg,

Since b should be more than 19.3 kJ / kg, we choose ether with (3 377 kJ / kg) as a substance for filling the capsules.

Calculate by the formula (3) the operating time of each cavity is CH-77

(l-Ojj 45l 308-298-t- 2l26 ToV o745 308-298)

-G

1 +

2.2610 P. 0 j

Oj, 45-50

5.41 -10

g

47.8-10 C 133 h

Thus, the switching of the capacitor 6 from one cavity to another must be performed every 133 hours.

The application of the proposed method of regulating the thermal regime allows. It is necessary to carry out the operation of the air conditioning system in underground structures without transporting the heat of condensation of the refrigeration unit to the surface, and in addition, to reduce the volume of cavities contained in the mountain massif serving to store the cooling water, which: will lead to lower costs.

Claims (1)

1. Method of regulating the thermal regime of underground structures, chakits cooling the air with a coolant circulating between the evaporator of the refrigerating machine and the air cooler, and removing the heat of condensation of the REFRIGERATING agent cooling water circulating between the condenser of the refrigerating machine and placed in the mountain massif hydro-insulated cavities characterized in that, in order to increase the efficiency of regulating thermal pe-t. press by use for tap //