KR20090010398U - . multi compressor system for cooling and heating system - Google Patents

Abstract

The cooling and heating system for a parallel multiple compressor of the present invention is a plurality of compressors connected in parallel to compress refrigerant gas at a high temperature and high pressure, and the cooling / heating is mutually switched by switching the direction of the high temperature and high pressure refrigerant liquid provided from the plurality of compressors. Four-way valves, an indoor exchanger which heat-exchanges with indoor air by liquefying the high-temperature / high-pressure refrigerant gas into a high-temperature / high-pressure refrigerant liquid, and a medium temperature refrigerant liquid such that the refrigerant liquid is reduced in pressure to evaporate at room temperature. A branch pipe is provided with an expansion valve for converting to low pressure, an evaporator for converting the medium and low pressure refrigerant liquid into a refrigerant gas, absorbing latent heat of external evaporation to exchange heat with outdoor air, and a unidirectional valve connected to the compressor of the condenser. And a connecting pipe connecting the diverging pipe to one joint and connecting the four-way valve and the indoor exchanger. A flow pipe is connected to the internal exchanger, the expansion valve, and the evaporator. The flow pipe between the expansion valve and the indoor exchanger is installed, and an electronic switching valve is installed to switch the opening / closing state during the cooling / heating switching. The unidirectional valve is installed in parallel to flow, and further comprises a circulation pipe for circulating the refrigerant to the compressor by connecting the refrigerant passed through the evaporator to the four-way valve.

Cooling / Heating, Compressors, Parallel, Multiple

Description

MULTI COMPRESSOR SYSTEM FOR COOLING AND HEATING SYSTEM}

The present invention relates to a cooling / heating system for a parallel multiple compressor, and more particularly, to install a simple pipeline and easily control the open state of the pipeline in a refrigeration cycle equipped with a plurality of compressors. The present invention relates to a cooling and heating system for a parallel multiple compressor that enables stable operation of a cooling and heating system.

With the recent development of the food industry, there are often examples of applying the indirect cooling method to the design application of the refrigeration system. In this case, the temperature of brine is operated by -7 ℃ system for agricultural products and -25 ℃ system for refrigerators storing frozen foods.

In the case of agricultural products, the respiratory heat at the time of initial wearing is large so that the refrigerator can be operated at full load until the respiratory heat is completely caught, but since the cooling load decreases by 40-50%, two or more freezers are considered in consideration of the partial load characteristics. It is preferable to operate the installation in parallel.

That is, the reason for using more than one compressor is to obtain the increased capacity from the cooling unit that cannot be obtained by operating a single compressor, and decreases when the cooling capacity is no longer available due to the failure of the compressor during the use of multiple compressors. By having one or more compressors that can remain in operation to provide a high level of cooling capability, it is possible to provide improved reliability of the overall apparatus.

However, the refrigerator of the parallel multiple compressor type as described above is a cold store (freezer refrigerator). In addition, as the use of low-temperature facilities such as low-temperature showcases increases and the facilities become more complicated, safety management and maintenance are difficult with the existing facilities.

Accordingly, a parallel multi-compressor system (MULTI COMPRESSOR SYSTEM), which has a low operating cost and a simple refrigeration piping system, is used. As such a conventional operation control method, various types of operation methods are known.

1 is a configuration diagram showing a refrigerant flow when the refrigeration system having a plurality of compressors according to the prior art is cooling, Figure 2 is a refrigerant flow when the refrigeration system having a plurality of compressors according to the prior art is heating The configuration diagram shown.

A refrigeration system having a plurality of compressors according to the prior art, as shown in Figures 1 and 2, a plurality of compressors (2, 4, 6, 8) for changing the low-temperature low-pressure gaseous refrigerant to high temperature and high pressure, Condensation means (condensation of outdoor heat exchanger (12), interior heat exchanger (14) of heating) and liquid refrigerant condensed by the condensation means of condensing gaseous refrigerant of high temperature and high pressure with liquid refrigerant while releasing heat to the surroundings Expansion mechanism 16 for expanding into a low-temperature, low-pressure two-phase refrigerant mixed with gas and liquid, and absorbs the surrounding heat to convert the two-phase refrigerant into a gaseous state

Evaporation means for evaporation (indoor heat exchanger 14 for cooling, outdoor heat exchanger 12 for heating), and liquid refrigerant that has not yet evaporated from the evaporation means flows into the compressors 2, 4, 6, and 8. Since it may cause a failure of the compressor (2, 4, 6, 8), in order to prevent this, the common accumulator (20) in which the liquid refrigerant is stored, and the compressor (2, 4, 6, 8) when cooling The high temperature and high pressure gas refrigerant from the gas is sent to the outdoor heat exchanger (12), and the refrigerant evaporated from the indoor heat exchanger (14) is sent to the accumulator (20), and the compressor (2, 4, 6) is heated. And a flow path switching valve 30 for sending the high temperature and high pressure gas refrigerant from 8) to the indoor heat exchanger 14 and sending the refrigerant evaporated from the outdoor heat exchanger 12 to the accumulator 20. It is configured by.

Each of the compressors 2, 4, 6, and 8 includes a compression unit having a compression chamber for compressing a refrigerant, and a motor unit for varying the compression chamber, and therein, oil for operation of the motor unit and the compression unit. This is put.

At one side of each of the compressors 2, 4, 6, and 8, the suction pipe 31 through which the gas refrigerant passing through the common accumulator 20 is sucked into each of the compressors 2, 4, 6, and 8, 32, 33, 34 are connected, and the other side of each of the compressors 2, 4, 6, and 8 are connected to discharge pipes 36, 37, 38, and 39 through which gas refrigerant compressed at high temperature and high pressure is discharged.

The discharge pipes 36, 37, 38, and 39 are connected to a lamination pipe 40 for guiding the coolant to the flow path switching valve 30, and check valves 36a are provided such that the high-temperature, high-pressure gas refrigerant is not flowed back. , 37a, 38a, 39a are mounted.

Referring to the operation of the conventional refrigeration system having a plurality of compressors configured as described above are as follows.

First, in the cooling operation, as shown in FIG. 1, the high temperature and high pressure refrigerant from the compressors 2, 4, 6, and 8 is sent to the outdoor heat exchanger 12 by the flow path switching valve 30. The refrigerant passing through the outdoor heat exchanger 12 is condensed into the liquid refrigerant in a gaseous state of high temperature and high pressure by heat exchange with ambient air, and then sent to the expansion mechanism 16. The refrigerant is expanded into a two-phase refrigerant of low temperature and low pressure while passing through the expansion mechanism 16, and then flows into the indoor heat exchanger 14, and evaporates to a gas state while passing through the indoor heat exchanger 14. By absorbing the surrounding heat, the surroundings of the indoor heat exchanger 14 are cooled.

The refrigerant passing through the indoor heat exchanger 14 is introduced into the common accumulator 20 by the flow path switching valve 30, and the refrigerant in the liquid phase remains in the common accumulator 20. The refrigerant in the gas phase is circulated through the suction pipes 31, 32, 33, 34 of each of the compressors 2, 4, 6, and 8 to each of the compressors 2, 4, 6, and 8.

Meanwhile, the oil contained in each of the compressors 2, 4, 6, and 8 is discharged together with the refrigerant discharged from the compressors 2, 4, 6, and 8 during the circulation of the refrigerant. After passing through the switching valve 30, the outdoor heat exchanger 12, the expansion mechanism 16, the indoor heat exchanger 14, the flow path switching valve 30 and the common accumulator 20, the compressor (2, 4, 6, and 8) are dispersed and recovered.

In the heating operation, as shown in FIG. 2, the high temperature and high pressure refrigerant from the compressors 2, 4, 6, and 8 is sent to the indoor heat exchanger 14. The indoor heat exchanger 14 heats the surroundings by dissipating heat of the refrigerant to the surroundings while the high temperature and high pressure gas refrigerant condenses into the liquid refrigerant, and expands to the low temperature and the low pressure while passing through the expansion mechanism 16 to the outdoor heat exchanger. The refrigerant flowing into the air 12 and passing through the outdoor heat exchanger 12 is evaporated in a gaseous state by heat exchange with ambient air.

The refrigerant passing through the outdoor heat exchanger (12) is introduced into the common accumulator (20) by the flow path switching valve (30), and the liquid refrigerant in the introduced refrigerant remains in the common accumulator (20). The refrigerant in the gas phase is circulated through the suction pipes 31, 32, 33, 34 of each of the compressors 2, 4, 6, and 8 to each of the compressors 2, 4, 6, and 8.

Meanwhile, the oil contained in each of the compressors 2, 4, 6, and 8 is discharged together with the refrigerant discharged from the compressors 2, 4, 6, and 8 during the circulation of the refrigerant. After passing through the switching valve 30, the indoor heat exchanger 14, the expansion mechanism 16, the indoor heat exchanger 12, the flow path switching valve 30 and the common accumulator 20, the compressor (2, 4, 6, and 8) are dispersed and recovered.

However, in a refrigeration system having a plurality of compressors according to the prior art, a suction pressure difference can be generated between the plurality of compressors 2, 4, 6, and 8, and the compressors 2, 4, 6, As shown in FIG. 3, the amount of oil recovered to each of 8) may cause a difference, and the life of some of the plurality of compressors 2, 4, 6, and 8 may be shortened.

In addition, in a cooling / heating system equipped with a plurality of compressors, a complicated bypass pipe is installed to enable cooling / heating switching, thereby lowering the installation efficiency of the cooling / heating system and reducing the installation cost.

Therefore, the main object of the present invention is to provide a simple pipeline installation in the refrigeration cycle equipped with a plurality of compressors and to easily control the open state of the pipeline to enable a stable operation of a cooling and heating system equipped with a plurality of compressors. There is.

In order to achieve the above object, the cooling and heating system for a parallel multiple compressor according to the present invention includes a plurality of parallel connected compressors for compressing a refrigerant gas at high temperature and high pressure, and a high temperature and high pressure refrigerant liquid direction provided from the plurality of compressors. Four-way valve to switch cooling / heating to each other, liquefied high-temperature / high pressure refrigerant gas to a high-temperature / high pressure refrigerant liquid, an indoor exchanger that exchanges heat with indoor air, and reduce the refrigerant liquid to evaporate at room temperature. An expansion valve for converting the refrigerant liquid into a medium temperature and a low pressure so as to occur, an evaporator that converts the medium and low pressure refrigerant liquid into a refrigerant gas, absorbs latent heat of evaporation, and exchanges heat with outdoor air, and is connected to the compressor of the condenser. Branch pipe with one-way valve is installed, and the branch pipe is connected by one joint to replace the four-way valve and indoor And a connection pipe for connecting a joint, and a flow pipe for connecting the indoor exchanger and the expansion valve and the evaporator to the joint, and an electronic switching valve for switching the opening and closing state at the time of cooling / heating switching between the expansion valve and the indoor exchanger. Installing a parallel unidirectional valve for allowing the refrigerant to flow only in one direction while installing the, and further comprises a circulation pipe for circulating the refrigerant to the compressor by connecting the refrigerant passed through the evaporator to the four-way valve.

According to the present invention, a high temperature valve is provided through a plurality of compressors by installing a high pressure valve in the connection pipe connecting the four-way valve and the branch pipe. It is configured to control the pressure of the high pressure refrigerant.

According to the present invention, a high pressure liquid separator is installed in the flow pipe between the indoor exchanger and the unidirectional valve, and a low pressure liquid separator is installed in the circulation pipe between the four-way valve and the compressor to separate the liquid refrigerant in the refrigerant gas. Configure to prevent liquidback.

As described above, the parallel multiple compressor refrigeration system of the present invention has the effect that it is possible to simply install the pipeline (branch, connecting pipe, flow pipe, circulation pipe) of the refrigeration cycle equipped with a plurality of compressors.

In addition, the refrigeration system for a parallel multiple compressor of the present invention is to enable the cooling and heating operation at a stable pressure of the cooling and heating system equipped with a plurality of compressors.

In addition, the refrigeration system for parallel multiple compressors of the present invention can easily control the open state of the pipeline has the effect of enabling a more stable switching of the cooling and heating system.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, in the drawings, the same components or parts are to be noted that the same reference numerals as possible. In describing the present invention, detailed descriptions of related known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

Figure 3 is a schematic diagram showing a cooling / heating system for a parallel multiple compressor of the present invention, Figure 4 is a schematic diagram showing a cooling / heating system for a plurality of parallel multiple compressors of the present invention.

As shown in Figure 3, the parallel multiple compressor refrigeration system of the present invention is a compressor 110, four-way valve 120, indoor exchanger 130, expansion valve 140, evaporator 150, branch pipe 160, connecting pipe 170, flow pipe 180 and circulation It consists of a tube 190.

That is, a plurality of compressors 110 connected in parallel to compress the refrigerant gas at high temperature and high pressure, and four-way valves 120 for switching cooling / heating mutually by switching the direction of the high temperature / high pressure refrigerant liquid provided from the plurality of compressors 110; The high temperature and high pressure refrigerant gas is liquefied and converted into a high temperature and high pressure refrigerant liquid, and an indoor exchanger 130 which exchanges heat with indoor air, and the refrigerant liquid is decompressed to a medium temperature and low pressure so as to evaporate at room temperature. An expansion valve 140 for converting, an evaporator 150 for converting the medium and low pressure refrigerant liquid into a refrigerant gas to absorb latent heat of evaporation and heat exchange with outdoor air, and a unidirectional valve 161 connected to the compressor 110 of the condenser are installed. And a branch pipe 160 connecting the branch pipe 160 to one joint to connect the four-way valve 120 and the indoor exchanger 130 to the joint. While installing a flow pipe 180 connecting the exchanger 130, the expansion valve 140 and the evaporator 150, while installing an electronic switching valve 181 to switch the opening and closing state at the time of cooling / heating switching between the expansion valve 140 and the indoor exchanger 130 The unidirectional valve 182 is installed in parallel to allow the refrigerant to flow only in one direction, and the circulation pipe 190 circulates the refrigerant to the compressor 110 by connecting the refrigerant passing through the evaporator 150 to the four-way valve 120.

In addition, the high-pressure valve 171 is installed in the connecting pipe 170 connecting the four-way valve 120 and the branch pipe 160 is provided through a plurality of compressors 110. To control the pressure of the high pressure refrigerant.

In addition, a high pressure liquid separator 183 is installed in the flow pipe 180 between the indoor exchanger 130 and the one-way valve 161, and a low pressure liquid separator 191 is installed in the circulation pipe 190 between the four-way valve 120 and the compressor 110 to separate the liquid refrigerant in the refrigerant gas. To prevent liquid back to the compressor 110.

As such, the operation of the refrigerant flow of the air conditioning system 110 for a parallel multiple compressor of the present invention is configured as follows.

First, when the plurality of compressors 110 operate to compress the refrigerant gas, the kinetic energy of the refrigerant gas molecules increases to obtain energy due to molecular collisions, thereby raising the temperature of the refrigerant gas.

In addition, the distance between molecules of the refrigerant is narrowed to increase the number of molecules per unit volume so that each refrigerant molecules are concentrated to each other to facilitate liquefaction at room temperature.

As described above, the refrigerant gas through the compressor 110 is a high temperature. It is converted into a high-pressure refrigerant liquid and flows to the four-way valve 120 through a branch pipe 160 provided with a unidirectional valve 161 connected to each compressor 110.

In particular, the high-temperature, high-pressure refrigerant liquid introduced into the branch pipe 160 through the plurality of compressors 110 flows into the connecting pipe 170 in which the plurality of branch pipes 160 are integrated into one, and the pressure is overloaded above the refrigerant pressure set through the high temperature valve 171. Is generated, the pressure of the refrigerant liquid is partially leaked to the outside to maintain the static pressure.

The four-way valve 120 converts the role of the indoor exchanger 130 according to the change in the direction of the valve so that the high temperature / high pressure refrigerant vapor flows to the indoor heat exchanger side, and heats the indoor air by heat-exchanging the condensation heat with the fluid to perform a heating function. Let's do it.

High temperature through the connection pipe 170 is connected to the four-way valve 120. The high-pressure refrigerant liquid is provided to the indoor exchanger 130, and the high-temperature refrigerant gas exits the compressor 110. The high-pressure refrigerant gas liquefies by taking heat away from the air while passing through the indoor exchanger 130. Convert to high pressure refrigerant liquid.

That is, in order to liquefy the refrigerant vapor compressed at the compressor 110 at a high temperature and high pressure by being compressed by the compressor 110, the indoor exchanger 130 has to take away the amount of heat equivalent to the latent heat of the refrigerant from the refrigerant vapor. The amount of heat that the refrigerant vapor condensed in the indoor exchanger 130 is taken away through the cooling water or air is equal to the difference between the enthalpy of the enthalpy of the inlet refrigerant vapor and the indoor exchange outlet refrigerant liquid.

Subsequently, medium temperature through the flow tube 180. The high-pressure refrigerant liquid flows into the expansion valve 140 through the unidirectional valve 182 and then through the indoor exchanger 130 to medium temperature. The pressure of the refrigerant liquid is lowered to easily evaporate the refrigerant liquid converted to high pressure at a relatively high temperature.

This means that even if the evaporation temperature is the same, if the condensation temperature is high, the amount of compression is increased, so the heat of condensation is also increased. If the evaporation temperature is low, the compression work amount is increased as the specific volume of the refrigerant vapor sucked into the compressor 110 increases. Therefore, the heat of condensation also increases.

Here, a high pressure liquid separator 183 is installed in the flow pipe 180 between the indoor exchanger 130 and the unidirectional valve 182 to separate the liquid refrigerant in the refrigerant gas.

Next, the pressure of the refrigerant liquid is lowered through the expansion valve 140. The reason is that low pressure of the refrigerant liquid tends to change into gas, and high pressure makes it difficult to change into gas so that the pressure of the refrigerant liquid is lowered so that evaporation occurs easily at room temperature.

Next, the evaporator is supplied with a medium liquid and low pressure refrigerant liquid through the flow pipe 180 to absorb the latent heat of evaporation from the air or liquid (water, brine, oil), etc., which is to be cooled, so that the refrigeration effect occurs. Low temperature. The low pressure refrigerant gas is converted into heat exchange.

The refrigerant gas heat-exchanged through the evaporator 150 is circulated back to the compressor 110 through the four-way valve 120 through the circulation pipe 190. In addition, a low pressure liquid separator 191 is installed in the circulation pipe 190 between the four-way valve 120 and the compressor 110 to separate the liquid refrigerant in the refrigerant gas, thereby preventing liquid back to the compressor 110, thereby preventing the compression efficiency of the compressor 110 from being reduced.

As shown in FIG. 2, the refrigeration system in which the parallel multiple compressors are installed can further install one or more parallel multiple compressors, thereby further improving the compression efficiency and improving the cooling / heating output.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a block diagram showing a refrigerant flow when the refrigeration system having a plurality of compressors according to the prior art cooling.

Figure 2 is a block diagram showing the refrigerant flow when the refrigeration system having a plurality of compressors according to the prior art heating.

Figure 3 is a system diagram showing a cooling / heating system for a parallel multiple compressor of the present invention.

4 is a schematic diagram of a cooling / heating system for a plurality of parallel multiple compressors of the present invention.

<Description of the symbols for the main parts of the drawings>

100: cooling / heating system 110: compressor

120: four-way valve 130: indoor exchanger

140: expansion valve 150: evaporator

160: branch pipe 161: unidirectional valve

170: connector 171: high pressure valve

180: flow pipe 181: electronic on-off valve

182: one-way valve 183: high pressure liquid separator

190: circulation valve 191: low pressure liquid separator

Claims (3)

In the air conditioner / heater, A compressor connected in parallel to a plurality of compressors for compressing the refrigerant gas at high temperature and high pressure; Four-way valve for switching the cooling / heating mutually by switching the direction of the high-temperature, high-pressure refrigerant liquid provided from the plurality of compressors, An indoor exchanger that heat-exchanges with indoor air by liquefying the high-temperature / high-pressure refrigerant gas and converting it into a high-temperature / high-pressure refrigerant liquid; An expansion valve for converting the refrigerant liquid into a medium temperature and a low pressure such that the refrigerant liquid is reduced in pressure to evaporate at room temperature; An evaporator which converts the medium-low pressure refrigerant liquid into a refrigerant gas and absorbs latent heat of evaporation to exchange heat with outdoor air; A branch pipe having a one-way valve connected to the compressor of the plurality of compressors is connected, and a connection pipe connecting the four branch pipes together to jointly connect the four-way valve and the indoor exchanger, and a flow connecting the indoor exchanger to the expansion valve and the evaporator. Install the pipe, but in the flow pipe between the expansion valve and the indoor exchanger is installed in parallel with the one-way valve to allow the refrigerant to flow in only one direction while installing an electronic switching valve that is switched on and off when switching the cooling / heating, evaporator Cooling and heating system for a parallel multiple compressor, characterized in that it further comprises a circulation pipe for circulating the refrigerant to the compressor by connecting the coarse refrigerant to the four-way valve. The method of claim 1, High temperature is provided through a plurality of compressors by installing a high pressure valve in the connecting pipe connecting the four-way valve and the branch pipe. Cooling and heating system for parallel multiple compressors, characterized in that configured to control the pressure of the high-pressure refrigerant. The method of claim 1, A high pressure liquid separator is installed in the flow pipe between the indoor exchanger and the unidirectional valve, and a low pressure liquid separator is installed in the circulation pipe between the four-way valve and the compressor to separate liquid refrigerant in the refrigerant gas, thereby preventing liquid back to the compressor. Cooling and heating system for a parallel multiple compressor, characterized in that configured to.

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