KR100248719B1 - Cooling cycle and heating cycle - Google Patents

Abstract

The present invention relates to a cooling and heating cycle, and in particular, to maintain the indoor hot air discharge temperature above a certain temperature during heating operation, and to perform the heating operation normally without raising the evaporation temperature according to the condensation temperature rise by adjusting the refrigerant flow rate. The purpose is to provide a cold cycle heating cycle structure that further improves the heating capacity of the product.

In order to realize this, the present invention provides a compressor for compressing a refrigerant and forcibly circulating the refrigerant in a refrigerant cycle including an indoor heat exchanger, an indoor heat exchanger for allowing indoor air and refrigerant to exchange heat, and an outdoor air and refrigerant. An outdoor unit which is an outdoor heat exchanger for exchanging heat, a refrigerant line at an inlet side of the inlet side of the indoor unit of the indoor unit, and an inlet / outlet side of the compressor are alternately installed to change the flow direction of the refrigerant during cooling or heating operation. An expansion valve for controlling the flow rate of the refrigerant and an adiabatic expansion between the outlet side of the indoor unit and the inlet side of the outdoor unit; Installed at the compressor inlet of the outdoor air outlet to pressurize the gas refrigerant and the liquid refrigerant above a certain level A liquid separator that is sent to the air, a bypass pipe connecting the receiver and the liquid separator, and a high temperature and high pressure liquid refrigerant that is installed in the bypass pipe to control the flow of the refrigerant and is made into a low temperature liquid refrigerant to be sent to the liquid separator. The heating cycle is composed of a control means and a heater installed on the compressor side to evaporate the liquid refrigerant entering the compressor.

Description

Cold, radiator cycle

The present invention relates to a cooling and heating device, and more particularly, to a cycle structure of a heater for maintaining a normal condensation temperature during a heating operation above a certain temperature and enabling a normal heating operation without an increase in the evaporation temperature according to a condensation temperature increase by controlling a refrigerant flow rate. It is about.

1 is a flowchart illustrating a conventional heater operation. Referring to the configuration, the compressor 3 compresses the refrigerant at a high temperature and high pressure, and the refrigerant compressed and discharged from the compressor 3 is sent to the indoor unit 1. Four sides (4) which are opened and closed so as to be opened, an expansion valve (6) which expands the refrigerant condensed in the indoor unit (1) and is sent through the receiver (5), and a low-temperature refrigerant passing through the expansion valve (6) is introduced. It consists of the outdoor unit 2 and the liquid separator 7 into which the gas evaporated from the outdoor unit 2 flows in through the four sides.

In the figure, reference numeral 8 denotes an indoor discharge fan, and 9 denotes an outdoor discharge fan.

The heater having such a structure is compressed by the compressor (3) during the heating operation and the refrigerant compressed at high temperature and high pressure is discharged and introduced into the indoor unit (1) through the four sides (4) to condense into a high-pressure supercooling liquid. The refrigerant condensed into the subcooled liquid flows into the expansion device 6 through the receiver 5 and expands into the refrigerant of low temperature and low pressure.

The refrigerant expanded at low temperature and low pressure absorbs heat from the outdoor unit and evaporates to a low temperature gas state. This low-temperature gas flows into the liquid separator 7 to separate the liquid refrigerant and the gas refrigerant generated on the pipe, and only the gas flows back into the compressor 3 to be compressed into a high-temperature discharge gas.

By repeating the above operation, the heating cycle is operated.

However, when the outdoor temperature falls to a low temperature, such a conventional heater has to have an evaporation temperature of the outdoor unit lower than the outdoor temperature for heat exchange with the outdoor, and when the outdoor evaporation temperature is lowered, the evaporation pressure is lowered and the condensation temperature and the pressure of the indoor unit are also lowered. You lose. Therefore, since the indoor discharge air temperature is lowered, a problem arises in that the indoor air cannot be heated by the discharge air.

When the compressor frequency is increased to increase the temperature of the indoor discharge air, the refrigerant circulation amount is increased, and the indoor condensation temperature and pressure are increased. However, when the expansion valve is operated according to the superheat degree of the outdoor unit heat exchanger, even if the frequency is increased to increase the refrigerant circulation, there is a problem that the refrigerant circulation amount is reduced by reducing the orbital expansion transition to maintain the superheat degree of the outdoor heat exchanger.

In addition, in order to maintain the indoor unit condensation temperature at a high temperature by increasing the frequency of the refrigerant circulating, the expansion valve needs to be opened as much as it can flow the increased refrigerant circulating amount. As a result, the elevated refrigerant circulation flows into the outdoor heat exchanger and increases the evaporation temperature and pressure.

Here, when the ambient temperature is low temperature (about -15 ℃ cold), the evaporation temperature of the outdoor heat exchanger must be lower than the ambient temperature to evaporate. The evaporation pressure must be lowered to lower the evaporation temperature above -15 ° C. To this end, it is necessary to reduce the refrigerant circulation by reducing the expansion valve trajectory. This is not possible without lowering the indoor condenser temperature.

That is, a problem occurs because the refrigerant circulation amount for maintaining the indoor condensation temperature at cold temperature and the refrigerant circulation amount required for the outdoor heat exchanger to evaporate at -15 ℃ is different.

In order to solve this problem, a liquid injection technique has been recently introduced as shown in FIG. 2. In the configuration, an electron valve 10, an expansion valve 2 (6 ') and a capillary tube 11 were added, and the compressor 3 was applied with a high pressure scroll compressor.

Generally speaking, rotary and reciprocating compressors cause fatal damage to the compressor when liquid refrigerant is introduced and liquid compression occurs. However, scroll compressors can be compressed even if liquid refrigerant is introduced. Thus, a compressor capable of injection is a scroll compressor.

Scroll compressor generally refers to a type in which an intermediate pressure part is formed by being composed of a low pressure part, a medium pressure, and a high pressure part, unlike a low pressure scroll compressor that compresses a refrigerant from the low pressure part to the low pressure part.

In the liquid injection technology, the indoor unit 1 is opened by introducing a liquid refrigerant into the intermediate pressure part of the compressor 3 by bypassing a part of the low temperature liquid refrigerant that has passed through the expansion valve 1 (6) to the outdoor unit 2 instead of sending it to the outdoor unit 2 (m2). Refrigerant circulation (m) is increased to increase the condensation temperature and pressure of the indoor heat exchanger, and to reduce the refrigerant circulation to m1 (= m-m2) in the outdoor heat exchanger to prevent the increase in evaporation temperature and pressure. The excess refrigerant circulation (m2) is decompressed in the expansion valve 2 (6 ') is introduced into the intermediate pressure portion of the high-pressure scroll compressor (3) and evaporated to prevent overheating of the compressor.

This is because when the outdoor temperature is lowered, the evaporation temperature is lowered and the frequency of the compressor 3 is increased to prevent the condensation temperature from being lowered at the same time. As the liquid refrigerant evaporates, it cools the compressor. It prevents the compressor from overheating and at the same time obtains the amount of heat required to evaporate the liquid refrigerant.

However, the liquid injection technology as described above uses a high-pressure scroll compressor, so that the heat generation of the compressor is very large and the discharge temperature of the compressor is excessively increased. Therefore, the operation conditions for preventing this are complicated and the heating capacity is lowered because it is operated in accordance with safety rather than performance. . In addition, the production is complicated and the algorithm for adjusting the amount of injection (m2) is complicated.

In addition, the heating cycle using the liquid injection and the high-pressure scroll compressor has many problems such as the price increase due to the small quantity order production because it is difficult to mass-produce due to the complicated structure and algorithm for securing the stability, the material cost increase and the difficulty of manufacturing accordingly. .

The present invention has been invented to solve the problems of the prior art as described above, a compressor for compressing a refrigerant and forcibly circulating the refrigerant in a refrigerant cycle including an indoor side heat exchanger, and an indoor side heat exchanger such that indoor air and refrigerant are heat exchanged. The indoor unit, which is a device, and the outdoor unit, which is an outdoor heat exchanger for exchanging outdoor air and refrigerant, and the refrigerant line on the outlet side of the inlet side outdoor unit of the indoor unit and the inlet / outlet side of the compressor are installed alternately. Four sides to change the flow direction of the refrigerant, an expansion valve for controlling the flow rate and adiabatic expansion of the refrigerant between the outlet side of the indoor unit and the inlet side of the outdoor unit, and the inlet side of the expansion outlet side of the indoor outlet side except for gas refrigerant A receiver that allows only liquid refrigerant to flow into the expansion valve and is installed at the compressor outlet of the outdoor outlet. Air-cooled liquid refrigerant and a predetermined level of liquid refrigerant to the compressor, a bypass pipe for connecting the receiver and the liquid separator, and the high-temperature and high-pressure liquid refrigerant flows installed in the bypass pipe to control the flow of refrigerant The heating cycle is composed of a refrigerant control means made of low temperature liquid refrigerant and sent to the liquid separator and a heater installed on the side of the compressor to evaporate the liquid refrigerant entering the compressor, thereby maintaining the condensation temperature over a certain temperature during the heating operation. It is an object of the present invention to provide a heating cycle for a cold climate that maintains heating capacity by operating a normal heating operation without increasing the evaporation temperature according to the increase of condensation temperature by adjusting the flow rate.

1 is a heating cycle of a conventional general heat pump.

2 is a heating cycle according to another embodiment of the conventional heat pump.

3 is a heat pump heating cycle of the present invention

4 is a heating cycle according to the first embodiment of the present invention

5 is a heating cycle according to a second embodiment of the present invention.

6 is a heating cycle according to a third embodiment of the present invention

7 is a heating cycle according to a fourth embodiment of the present invention.

8 shows a fifth embodiment of the present invention,

(A) is a heating cycle according to the embodiment.

(B) is a schematic diagram of a distributor applied to the embodiment.

9A is a schematic diagram of a receiver of the present invention.

(B) is the structure diagram of the liquid separator.

*** Explanation of symbols for the main parts of the drawing ***

101: indoor unit 102: outdoor unit

103: compressor 104: four sides

105: receiver 106: expansion valve

107: liquid separator 108,109: fan

110: electron valve 111: capillary tube

112: bypass piping 120,121: check valve

130: second expansion side 140: distributor

The present invention is described in detail below with reference to FIGS. 3 to 9.

Referring to the basic configuration of the present invention first, as shown in FIG. 3, a compressor 103 for compressing a refrigerant and forcibly circulating the refrigerant in a refrigerant cycle including an indoor side heat exchanger, and an indoor side heat exchanger such that indoor air and refrigerant are heat exchanged. The indoor unit 101, which is a device, the outdoor unit 102, which is an outdoor side heat exchanger for exchanging outdoor air and refrigerant, the inlet side of the indoor unit 101, the outlet side of the outdoor unit, and the inlet and outlet side of the compressor 103. Refrigerant lines are alternately installed to control the flow rate of the refrigerant between the four-sided 104 to change the flow direction of the refrigerant during cooling or heating operation, the outlet side of the indoor unit 101 and the inlet side of the outdoor unit 102 and An expansion valve 106 for adiabatic expansion, an inlet side of the outlet side expansion valve of the indoor unit, and a receiver 105 for allowing only liquid refrigerant except the gas refrigerant to flow into the expansion valve; A liquid separator 107 which is installed at an outlet compressor inlet and sends a gas refrigerant and a liquid refrigerant of a predetermined level or more to the compressor, a bypass pipe 112 connecting the receiver 105 and the liquid separator 107, and the bypass It is installed in the pass pipe 110 to control the flow of the coolant 110 and the bypass pipe 111 is installed in the bypass pipe 111 to operate the high-temperature and high pressure liquid refrigerant flowing from the receiver 105 at low temperature The refrigerant cycle is composed of a capillary tube 111 made of the liquid refrigerant to the liquid separator 107 and a heater 113 installed on the compressor side to evaporate the liquid refrigerant entering the compressor 103.

In the figure, reference numeral 108 denotes an indoor side discharge fan, and 109 denotes an outdoor side discharge fan.

The operation of the heater configured as described above is the hot gas discharged from the compressor 103 is condensed into a high temperature liquid in the indoor heat exchanger 101, the discharge fan 108 is warm air to the room by using the condensation heat generated at this time Send it to be heated. Then, the gas refrigerant generated by heat transfer or pressure loss with the surroundings is separated from the receiver 105, and only the liquid refrigerant is sent to the expansion valve 106 to reduce the pressure with the low temperature liquid refrigerant. The low temperature liquid refrigerant absorbs the surrounding heat in the outdoor unit 102 and changes to a low temperature gas refrigerant. The gas refrigerant flows into the compressor 103 via the liquid separator 107 and is compressed into a high temperature gas refrigerant. The heating operation is performed while repeating the above steps.

Here, even when operating at the refrigerant circulation m (= m1), the indoor condensation temperature (T7) is maintained above a certain temperature, the evaporation temperature (T1) of the outdoor heat exchanger 101 can be maintained lower than the outdoor air temperature (T3). have. However, when the outdoor temperature (T3) is lowered to a low temperature, the evaporation pressure and the condensation pressure are simultaneously lowered, and the frequency of the compressor 103 is increased to maintain the condensation pressure, thereby increasing the refrigerant circulation amount, and the expansion valve 106. By adjusting the trajectory is a lot of refrigerant flows.

Increasing the amount of refrigerant increases the evaporation temperature of the outdoor unit to approach the outdoor temperature. When the outdoor unit evaporation temperature and the outdoor temperature difference TDT are lowered to a predetermined temperature or lower, the electromagnetic transition is turned on to bypass a part of the flow rate m 2 to the liquid separator 107. Therefore, by reducing the trajectory of the expansion valve to reduce the amount of refrigerant circulation flowing into the outdoor unit (102). The outdoor unit 102 is reduced in the refrigerant circulation amount and the evaporation temperature according to the expansion valve trajectory adjustment to correspond to the decrease in the outdoor air temperature (T3).

The refrigerant m2 bypassed by the liquid separator 107 is mixed in a liquid and gaseous state, flows into the compressor 103, and absorbs heat of the compressor heater 103 ′ to evaporate. The compressor used in the present invention is capable of liquid compression as a low pressure scroll compressor.

The indoor unit (101) flows a m refrigerant to maintain a high temperature and high pressure, and in consideration of the outdoor temperature, the m1 (m-m2) refrigerant is flowed to the outdoor unit 102 to adjust the expansion valve 106 to allow evaporation at a lower temperature than the surroundings. , The m2 refrigerant flowing along the bypass pipe 112 absorbs the heat generated by the compressor and the heater from the compressor 103 to evaporate, thereby allowing normal heating operation while maintaining the indoor discharge temperature at a certain temperature at a low temperature. .

In the bypass structure 112, the high temperature and high pressure liquid refrigerant is converted into a low temperature and low pressure liquid refrigerant while passing through the capillary tube 111, and the liquid separator 107 serves to buffer the pressure difference between m1 and m2. This is because when the refrigerant passing through the capillary tube 111 and the expansion valve 106 may encounter a pressure difference, pulsation and vibration may occur.

The receiver 105 is configured to send the refrigerant entering m into the liquid state in m1 and m2, and the liquid separator 107 sends the refrigerant in the liquid + gas state to the compressor 103 when the liquid refrigerant is collected in a predetermined amount or more. It is.

The bypass structure 112 is a structure connected to the receiver 105, connected to the capillary 111 through the electron valve 110, and connected to the liquid separator 107.

4 illustrates a cycle according to the first embodiment of the present invention, in which a heater 107 ′ is installed in the liquid separator 107 to evaporate the liquid refrigerant flowing into the liquid separator 107 in the liquid separator.

That is, the heater 107 ′ is installed in the liquid separator 107 to improve the evaporation capacity by providing the heat amount necessary for evaporation, and to reduce the load due to the liquid compression in the compressor, a heat source for evaporating the refrigerant flow rate of m 2. Since the liquid separator heater 107 'is added to the compressor heating and the compressor heater, the evaporation performance is improved and the amount of the liquid refrigerant sucked into the compressor 103 is reduced, so that the amount of evaporation in the compressor 103 is reduced and the compressor operating load is reduced. Done.

5 illustrates a cycle according to the second embodiment of the present invention, and the receiver 105 in the bypass structure 112 connected to the receiver 105, the electron valve 110, the capillary 111, and the liquid separator 107. The refrigerant passing through) is first decompressed in the capillary tube 111, and the refrigerant flows into the liquid separator 107 through the electron valve 110.

Since the liquid refrigerant of the high temperature and high pressure in the receiver 105 flows into the electronic valve 110 after the pressure is reduced in the capillary tube 111, the load of the electronic valve is reduced during the electronic valve on / off control, thereby preventing the electronic valve from malfunctioning and providing rapid on / off. Off control is made.

That is, the electronic valve 110 receives the load due to the very small pressure difference between the low pressure and the low pressure as compared with the very large load due to the pressure difference between the high pressure and the low pressure.

FIG. 6 illustrates a cycle according to a third embodiment of the present invention. In the bypass pipe 112 structure connected to the receiver 105, the electron valve 110, the capillary tube 111, and the liquid separator 107, the electronic valve is turned on. The check valve 120 is installed on the bypass pipe 112 to prevent the refrigerant backflow from the liquid separator 107 caused by the temporary cycle imbalance to the bypass pipe 112.

In addition, in the structure in which the refrigerant decompressed in the expansion valve 106 and passed through the outdoor unit 102 is introduced into the liquid separator 107 through the four sides 104, the transient cycle imbalance causes the four sides of the liquid separator 107 to be separated. The check valve 121 for preventing the refrigerant flowing back to the 104 is a structure provided between the liquid separator 107 and the four sides 104.

7 shows a cycle according to a fourth embodiment of the present invention, an electronic valve for controlling the flow of refrigerant on / off on a bypass pipe 112 connecting the receiver 105 and the liquid separator 107; The second expansion valve 130 is configured to simultaneously perform the function of the capillary tube installed for controlling the refrigerant flow rate and reducing the pressure, and to linearly control the refrigerant flow rate bypassed.

In the present exemplary embodiment, the control expansion side 130 is linearly controlled to variably control the refrigerant flow rate m2 according to the refrigerant flow rate fluctuation and the compressor operating conditions. In addition, it is possible to maintain the optimum operating conditions in conjunction with the first expansion edge 106.

FIG. 8A illustrates a cycle according to the fifth embodiment of the present invention. In the pipe connecting the receiver 105 and the liquid separator 107, the receiver 105 passes through the receiver 105 to the expansion valve 106. The coolant distributor 140 is installed in the thin mid-point pipe to distribute the coolant through the bypass pipe 112.

By doing so, it is possible to use a general-purpose receiver, without having to manufacture a receiver separately.

8B shows a schematic structural diagram of the distributor 140 in the fifth embodiment.

9A and 9B show the structures of the receiver 105 and the liquid separator 107 applied to the cycle of the present invention, respectively. The receiver 105 of (A) flows from the indoor unit 101. Shows a structure for sending the refrigerant to the electron valve 110 and the expansion valve 106, (b) the liquid separator 107 is connected to the four sides 104, the bypass pipe 112 and the compressor 103. Therefore, according to the increase in the amount of refrigerant flowing from the four sides and the bypass pipe, the liquid refrigerant may be sent to the compressor or the gas refrigerant may be sent, and a in the figure shows the variation of the liquid refrigerant.

As described above, the heater cycle structure of the present invention can maintain the indoor hot air discharge temperature above a certain temperature. Due to this effect, the evaporation temperature must be increased in a cold district but the evaporation temperature is increased while maintaining the condensation temperature by controlling the refrigerant flow rate. Without heating operation can be performed normally, it can have the effect of further improving the heating capacity of the product.

Claims (8)

A compressor for compressing the refrigerant to forcibly circulate the refrigerant in a refrigerant cycle including an indoor heat exchanger; An indoor unit that is an indoor side heat exchanger for allowing indoor air and refrigerant to exchange heat, An outdoor unit that is an outdoor heat exchanger for exchanging outdoor air and refrigerant, A refrigerant line at the inlet side of the indoor unit and the outlet side of the compressor unit at the inlet and outlet side of the indoor unit are alternately installed to change the refrigerant flow direction during cooling or heating operation; An expansion valve for controlling the flow rate of the refrigerant and the adiabatic expansion between the outlet side of the indoor unit and the inlet side of the outdoor unit, A receiver installed at the inlet side of the inflation valve to allow the liquid refrigerant except the gas refrigerant to flow into the inflation valve; A liquid separator installed at the compressor inlet of the outdoor air outlet and sending gas refrigerant and a liquid refrigerant of a predetermined level or more to the compressor; Bypass pipe connecting the receiver and the liquid separator, Cooling and heating cycle, characterized in that made by the refrigerant control means installed in the bypass pipe to control the flow of the refrigerant flowed to the liquid separator of the high temperature and high pressure liquid refrigerant flowed to the liquid separator. The method of claim 1, The refrigerant control means and the electronic valve for controlling the flow of the refrigerant; Cooling and heating cycle characterized in that the high-temperature, high-pressure liquid refrigerant flowing from the receiver during operation of the electronic valve made of a low-temperature liquid refrigerant made of a capillary tube sent to the liquid separator. The method of claim 1, The refrigerant control means is a cooling, heating cycle characterized in that the role of the electron valve and the capillary tube and at the same time consisting of an expansion valve for linearly controlling the flow of the refrigerant. The method of claim 1, The liquid separator is characterized in that the heat source for evaporating the liquid refrigerant is characterized in that the cooling, heating cycle. The method of claim 1, Cooling and heating cycle, characterized in that between the capillary and the liquid separator and between the four sides and the liquid separator is provided with a check valve for preventing the refrigerant flow back. The method of claim 1, Distributor is installed between the receiver and the expansion valve, The distributor cycle, characterized in that the liquid separator and the bypass pipe is connected. The method of claim 1, The receiver is a coolant, air conditioner cycle characterized in that the refrigerant flows from the indoor unit is made of a structure to discharge the liquid refrigerant to the bypass pipe and the expansion valve. The method of claim 1, Heater cycle, characterized in that the heater is installed on the compressor side to evaporate the liquid refrigerant entering the compressor.

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