JP4749127B2 - Muffler - Google Patents

Description

  The present invention relates to a muffler for attenuating pulsation of refrigerant discharged from a compressor. More specifically, the present invention relates to a narrow diameter portion at both ends, a spherical portion expanded from each narrow diameter portion into a substantially spherical shape, and both spherical portions. The present invention relates to a muffler provided with a muffler body composed of a large-diameter portion therebetween, and connection piping connected to both narrow-diameter portions of the muffler body.

This type of muffler is disclosed in Patent Document 1 and the like. According to Patent Document 1, there is a small-diameter portion having a predetermined length from the end portion, a spherical portion that is expanded in a substantially spherical shape from the tube expansion start position is provided, and a large-diameter portion is formed from the spherical surface end position. A connection pipe connected to the outlet side of the heat exchanger or a heat exchanger is inserted up to a stopper formed in the small diameter portion, and the connection pipe and the small diameter portion are welded.
Japanese Patent Laid-Open No. 2002-90001

  However, these connecting pipes and muffler bodies are often made of steel plates and have to be painted. Further, the muffler having a structure in which the spherical portion and the large diameter portion which are separate bodies are welded has to be further welded.

  Then, an object of this invention is to provide the muffler which can reduce welding as much as possible and can also make a painting unnecessary.

  For this reason, the first invention provides a muffler body comprising a narrow diameter portion at both ends, a spherical portion expanded from each narrow diameter portion into a substantially spherical shape, and a large diameter portion between both spherical portions, In a muffler that includes connection pipes connected to both narrow diameter portions and attenuates pulsation of refrigerant discharged from the compressor, the muffler body and the connection pipe are made of copper, and the large diameter of the muffler body The whole part and at least a part of both spherical parts are covered with a stainless steel cover.

  According to a second aspect of the present invention, there is provided a muffler main body comprising a narrow diameter portion at both ends, a spherical portion expanded from each of the small diameter portions into a substantially spherical shape, and a large diameter portion between both spherical portions, and both fine portions of the muffler main body. In a muffler comprising a connection pipe connected to the diameter part and attenuating pulsation of refrigerant discharged from the compressor, the muffler body and the connection pipe are made of copper, and the entire large diameter part of the muffler body And at least a part of both spherical portions is covered with a stainless steel cover so as to be in close contact with the outside.

  3rd invention is the invention which concerns on 1st or 2nd muffler, The heat exchanger for heating which heat-exchanges the outlet side of the compressor of a heat pump type hot water heater, and the refrigerant | coolant and water which were compressed with the said compressor It is characterized by being disposed between the two.

  According to a fourth invention, in the invention according to the first or second muffler, a part of a transcritical refrigerant cycle apparatus using a refrigerant whose high pressure side is a supercritical pressure is configured.

  In the present invention, since the muffler main body and the connecting pipe are made of copper and the cover is made of stainless steel, no painting is required, and the cost can be reduced. In addition, since both ends of the cover are brought into close contact with the spherical surface portion, the muffler body and the cover are integrated, and the muffler body is covered with the cover, so that the pressure resistance is enhanced.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram of a circuit of a heat pump type hot water heater to which the present invention is applied. This heat pump type hot water heater, which will be described later, is formed by connecting a hot water storage tank, a circulation pump and a heat exchanger for heating in a ring shape with hot water piping. Hot water storage circuit 1K, hot water supply circuit 2K for supplying hot water in the hot water storage tank to the utilization section, a compressor capable of adjusting the capacity of a two-stage compression type, the heat exchanger for heating, the cooler, and the first electric expansion valve And a refrigerant circuit R formed by connecting the evaporators in an annular shape with a refrigerant pipe, and a refrigerant circuit between the heat exchanger for heating and the cooler, and an electromagnetic on-off valve and a second electric expansion valve in the middle And an intermediate injection circuit M that includes the cooler and returns a part of the refrigerant discharged from the heating heat exchanger to the middle between the low pressure side and the high pressure side of the compressor.

  The refrigerant circuit R constitutes a transcritical refrigerant cycle device that uses a refrigerant whose high pressure side becomes a supercritical pressure, and will be described in detail below. The compressor 1 with adjustable two-stage compression capability, the heating heat exchanger 3, the cooler 4, the 1st electric expansion valve 6, and the evaporator 7 are connected cyclically | annularly by refrigerant | coolant piping RH. Reference numeral 1 denotes an internal intermediate pressure type two-stage compression rotary compressor (hereinafter referred to as a “compressor”) capable of adjusting the capacity to suck and compress carbon dioxide as a refrigerant to be a high temperature and high pressure, and the first and second rotary compression elements 1A. 1B. A muffler 2 is connected to the refrigerant outlet side of the compressor 1 and attenuates / reduces pressure pulsations of refrigerant discharged from the compressor 1 to reduce noise, and 3 includes a refrigerant flow path 3A and a water flow path 3B. The refrigerant-to-water heat exchanger for heating to exchange heat between the refrigerant and the water 4 is a cooler having a primary flow path 4A and a secondary flow path 4B, and 5 is a heat for the high-pressure side refrigerant and the low-pressure side refrigerant. An internal heat exchanger having a primary flow path 5A and a secondary flow path 5B to be exchanged, 6 is connected to the outlet side of the primary flow path 5A of the internal heat exchanger 5 and is used as a decompression means for decompressing the refrigerant. 1 is an electric expansion valve, 7 is an evaporator that evaporates the refrigerant decompressed by the first electric expansion valve 6 and exchanges heat with the outside air, and 8 is an outlet side of the secondary flow path 5B of the internal heat exchanger 5 and the compressor 1. It is an accumulator which is a gas-liquid separator connected between the suction side. The refrigerant that has not been evaporated by the evaporator 7 is caused to flow through the secondary flow path 5B of the internal heat exchanger 5 to exchange heat with the refrigerant flowing through the primary flow path 5A, thereby further gasifying the refrigerant.

  The intermediate injection circuit M includes an electromagnetic on-off valve 10, a second electric expansion valve 11, and a secondary flow path 4 </ b> B of the cooler 4, and the heating refrigerant-to-water heat exchanger 3 and the internal heat exchanger 5. When the electromagnetic on-off valve 10 is opened, the refrigerant is returned to the middle between the high pressure side and the low pressure side of the compressor 1. When carbon dioxide is used as a refrigerant, the refrigerant is used in a gasified state, that is, in a supercritical region. In this supercritical region, carbon dioxide becomes high pressure and vapor density is high, so there is a problem that the internal high pressure compressor places a load on the sealed container, but the internal intermediate pressure type two-stage compression rotary compressor with internal intermediate pressure is used. That is, the compressor 1 is used.

  Reference numeral 12 denotes a defrosting solenoid valve that opens when a detection sensor (not shown) detects that the amount of frost generated and adhered to the evaporator 7 exceeds a certain level. The secondary flow path 4B of the cooler 4 and the compressor 1 is disposed at an intermediate position of the branch path 13 that branches from the middle between the high-pressure side and the low-pressure side and returns to the evaporator 7.

  The hot water storage circuit 1K is configured by connecting a hot water storage tank 20 for storing hot water, a circulation pump 28, a heat exchanger 3 for heating, and a flow rate adjusting valve 29 as a flow rate adjusting means in an annular shape with hot water piping.

  The hot water supply circuit 2K is a circuit for supplying hot water in the hot water storage tank 20 to the utilization section, a water pressure reducing valve 21 with a check valve for supplying tap water to the hot water storage tank 20, and a hot water for taking out hot water from the hot water storage tank 20. A pipe 22, a bypass pipe 24 extending from the outlet side of the water pressure reducing valve 21 to the mixing valve 23 connected to the hot water pipe 22, a hot water filled pipe 25 branched from the hot water pipe 22 to the bathtub 30, and the hot water filled pipe 25 A solenoid valve 26 and a pressure relief valve 27 connected to the hot water discharge pipe 22 upstream of the mixing valve 23 are provided.

  Next, description will be made based on the control block diagram of FIG. The microcomputer 40 is a central processing unit (CPU) 41 that controls the entire operation related to hot water supply including the operation of the heat pump unit as an outdoor unit equipped with the refrigerant circuit R in the heat pump hot water supply device. A RAM (Random Access Memory) 42 as a storage device for storing data and a ROM (Read Only Memory) 43 for storing a program relating to hot water supply operation including a program relating to refrigeration cycle operation are included. Based on the data stored in the RAM 42, the CPU 41 controls the operation related to hot water including the refrigeration cycle operation of the heat pump type hot water heater according to the program stored in the ROM 43.

  And the capacity | capacitance of the said hot water storage tank 20 is 370 liters, for example, and the hot water temperature detection sensors TS1, TS2, TS3, TS4, TS5, TS6 and TS7 are provided with a vertical interval from the lower part to the upper part of the hot water tank 20, Since the temperature of the water heater before boiling is up to 55 ° C., when the detected hot water temperature of each sensor is 55 ° C. or higher, hot water is stored from the upper end of the hot water tank 20 to that position, and there is remaining hot water. Judge. At this time, the detection sensor TS1 is disposed at a position where the remaining hot water amount is 350 liters, TS2 is also 300 liters, TS3 is 250 liters, TS4 is 200 liters, TS5 is 150 liters, TS6 is 100 liters, and TS7 is 50 liters. .

  When the temperature of the hot water storage starts to be less than the minimum hot water storage amount (for example, 150 liters) and the detection temperature of the detection sensor TS5 falls below 55 ° C., which is a temperature for determining the hot water storage state, the microcomputer 40 detects that the hot water storage amount is the detection sensor TS5. The heat pump water heater is heated up and started to operate, and is controlled so as to always maintain the minimum amount of stored hot water.

  Next, the muffler 2 will be described with reference to FIGS. The muffler 2 is a copper muffler main body comprising a small diameter portion 2A at both ends, a spherical portion 2B expanded from each of the small diameter portions 2A into a substantially spherical shape, and a cylindrical large diameter portion 2C between both spherical portions 2B. 2H and copper connection pipes 2S1 and 2S2 connected to both narrow diameter portions 2A and 2A of the muffler main body 2H.

  And after inserting each connection piping 2S1, 2S2 in each small diameter part 2A until the stopper P which determines the insertion allowance formed in the outer peripheral surface of each connection piping 2S1, 2S2 contact | abuts to each small diameter part 2A end surface , Fix by welding. Next, the entire large diameter portion 2C and at least a part of both spherical surface portions 2B of the muffler main body 2H are covered with a stainless steel cover 50 so as to be in close contact from the outside. The cover 50 covers up to a part of both spherical surface portions 2B, but may cover all of the spherical surface portions 2B and the small diameter portion 2A.

  In this covering, first, one end of a cylindrical cover 50 whose inner diameter is slightly larger than the outer diameter of the large diameter portion 2C (substantially the same diameter) is narrowed by pressing, that is, one spherical surface of the muffler body 2H. The spherical portion 50A is formed in a state of being narrowed and narrowed so that the outer diameter and the inner diameter of the portion 2B become substantially the same diameter, and the muffler body 2H is inserted into the cover 50 until it cannot move. Next, after this insertion, the other end portion of the cover 50 is similarly pressed, and the spherical portion 50A is formed in a state in which the outer diameter and the inner diameter of the other spherical portion 2B are narrowed and narrowed to be substantially the same diameter. Then, the muffler body 2H and the cover 50 are integrated and covered.

  The muffler 2 configured as described above is connected between the outlet side of the compressor 1 and the heat exchanger 3 for heating, that is, the connecting pipe 2S2 is connected to the heating heat exchanger 3 via the pipe, and the connecting pipe 2S1 is connected to the heat exchanger 3 for heating. It connects to the compressor 1 via piping. Therefore, as described above, the muffler main body 2H and the connection pipes 2S1 and 2S2 are made of copper and the cover 50 is made of stainless steel, so that painting is unnecessary, and the cost can be reduced. Further, both ends of the cover 50 are brought into close contact with each other so that the outer diameter and the inner diameter of the spherical portion 2B are substantially the same diameter, and the muffler body 2H and the cover 50 are integrated to form a muffler body 2H. Since the cover 50 is covered with the cover 50, the pressure resistance is enhanced, and the occurrence of cracks in the muffler body 2H can be prevented. For this reason, the original function of the muffler 2 that attenuates and reduces the pressure pulsation of the refrigerant discharged from the compressor 1 to reduce noise can be exhibited.

  Here, in addition to hot water supply, this heat pump type water heater can also perform heating such as floor heating operation and bathroom heating. However, for convenience of explanation, this heating operation is omitted. First, the hot water storage operation will be described below assuming that the outside air temperature detected by the outside air temperature detection sensor 45 is at a predetermined temperature, for example, a temperature that does not fall below minus 5 ° C (minus 5 ° C or higher).

  First, when hot water is stored in the hot water storage tank 20, the circulation pump 28 is operated, and the hot water storage tank 20 → the circulation pump 28 → the water flow path 3B of the refrigerant-to-water heat exchanger 3 → the flow rate adjusting valve 29 → the hot water storage tank 20 in this order. Hot water flows and is stored in the hot water tank 20.

  In the refrigerant circuit R, the compressor 1 is operated, and the outside air temperature by the outside air temperature detection sensor 45 is a temperature that does not fall below minus 5 ° C., so the electromagnetic on-off valve 10 is closed. Therefore, compressor 1 → muffler 2 → refrigerant flow path 3A of refrigerant-to-water heat exchanger 3 → primary flow path 4A of cooler 4 → primary flow path 5A of internal heat exchanger 5 → first electric expansion valve 6 → evaporation The refrigerant flows in the order of the secondary passage 5B of the internal heat exchanger 5 → the accumulator 8 → the compressor 1. At this time, the pressure pulsation of the refrigerant discharged from the compressor 1 is attenuated / reduced by the muffler 2 and noise is reduced.

  At this time, during such a normal cycle operation, when the compressor 1 is operated at an operation frequency of about 100 Hz and the first electric expansion valve 6 is changed from the fully closed state to the fully opened state from 0 step to 500 steps. The CPU 41 controls the first electric expansion valve 6 so that it is throttled in the state of 100 steps, and the second electric expansion valve 11 is set from 0 to 500 steps from the fully closed state to the fully opened state. Control is performed so that the state is reduced in the state of 50 steps.

  The hot water stored in the hot water tank 20 is adjusted to an appropriate temperature by the tap water and the mixing valve 23 via the bypass pipe 24, hot water to the kitchen and shower and hot water to the bathtub 30 via the hot water pipe 22. Used for tension. And if hot water supply is performed, water supply will be performed to the hot water storage tank 20 through the water pressure reducing valve 21 disposed in the middle of the water supply pipe.

  Then, during the hot water storage operation as described above, if the outside air temperature sensor 45 detects that the outside air temperature has fallen below minus 5 ° C., the heating capacity will decrease, so the CPU 41 detects that in order to increase the heating capacity. In response to the information, the compressor 1 is controlled to operate with the operating frequency lowered from about 100 Hz to 55 Hz, and the opening degree of the first electric expansion valve 6 is in a state of 100 steps to 450 steps (the opening degree is sufficiently opened). So that the opening degree of the second electric expansion valve 11 does not flow from 50 steps to 20 steps (note that it starts to flow in about 30 steps). Then, the electromagnetic on-off valve 10 that has been closed is then opened.

  Then, after the electromagnetic opening / closing valve 10 is opened, the opening degree of the second electric expansion valve 11 is changed from 20 steps (almost no flow) to 50 steps after a predetermined time (for example, several seconds later). Since the CPU 41 controls the second electric expansion valve 11, when it begins to exceed about 30 steps, the refrigerant begins to flow into the intermediate injection circuit M and is returned to the middle between the high pressure side and the low pressure side of the compressor. That is, compressor 1 → muffler 2 → refrigerant flow path 3A of refrigerant to water heat exchanger 3 → primary flow path 4A of cooler 4 → primary flow path 5A of internal heat exchanger 5 → first electric expansion valve 6 → evaporation In addition to the refrigerant flowing in the order of the secondary vessel 5B of the internal heat exchanger 5 → the accumulator 8 → the compressor 1, the refrigerant passing through the refrigerant channel 3A of the refrigerant-to-water heat exchanger 3 is supplied with the electromagnetic on-off valve 10 The second electric expansion valve 11, the secondary flow path 4B of the cooler 4, and the intermediate between the high pressure side and the low pressure side of the compressor 1 are also returned.

  As a result, the second electric expansion valve 11 is substantially closed and no refrigerant flows, so that a large pressure and temperature change due to the refrigerant hardly occurs when the electromagnetic on-off valve 10 is opened. Reliability and durability can be improved.

  Thereafter, the CPU 41 controls the first electric expansion valve 6 to be throttled from 450 steps to 80 steps so that the compressor 1 operates at an operation frequency of about 55 Hz to 100 Hz, and the second electric expansion. For example, the valve 11 is controlled so as to be throttled in the state of 80 steps, and is controlled so that the refrigerant flows through the intermediate injection circuit M (hereinafter referred to as “split cycle operation”).

  In addition, during the hot water storage operation as described above, the CPU 41 detects that the outside air temperature has become minus 5 ° C. or more by the outside air temperature detection sensor 45 in the state where the split cycle operation is performed as described above, the CPU 41 performs the split cycle. Control is performed so that the operation is changed to the normal cycle operation. That is, the CPU 41 receives the detection information that the outside air temperature has become minus 5 ° C. or more, and controls the compressor 1 to operate with the operating frequency lowered from about 100 Hz to 55 Hz. The opening degree is changed from 80 steps to 450 steps (open state, ie, the refrigerant is not squeezed), and the opening degree of the second electric expansion valve 11 is hardly changed from 80 steps to 20 steps (30 The flow is controlled in such a manner that the flow starts in steps), and then the electromagnetic on-off valve 10 is controlled to be closed. Accordingly, the electromagnetic on-off valve 10 is closed in this way, so that no refrigerant flows into the intermediate injection circuit M.

  As a result, the second electric expansion valve 11 is effectively closed and no refrigerant is allowed to flow, so that a large pressure and temperature change due to the refrigerant hardly occurs when the electromagnetic on-off valve 10 is closed. Reliability and durability can be improved.

  Thereafter, the CPU 41 controls the first electric expansion valve 6 to be throttled from 450 steps to 100 steps so that the compressor 1 operates at an operation frequency of about 55 Hz to 100 Hz, and the second electric expansion. Although the valve 11 is controlled to be in a state of 20 steps to 50 steps (standby state), since the solenoid on-off valve 10 is closed, no refrigerant flows into the intermediate injection circuit M, and the compressor 1 → the muffler 2 → The refrigerant flow path 3A of the refrigerant-to-water heat exchanger 3 → the primary flow path 4A of the cooler 4 → the primary flow path 5A of the internal heat exchanger 5 → the first electric expansion valve 6 → the evaporator 7 → the internal heat exchanger 5 A normal cycle operation in which the refrigerant flows in the order of secondary flow path 5B → accumulator 8 → compressor 1 is performed.

  In this embodiment, when the outside air temperature detected by the outside air temperature detection sensor 45 is below a predetermined temperature, for example, minus 5 ° C., the split cycle operation is performed. When the outside air temperature is minus 5 ° C. or more, the normal cycle operation is performed. However, the present invention is not limited to this. For example, when the temperature is minus 5 ° C. or lower, the split cycle operation may be performed. When the temperature exceeds minus 5 ° C., the normal cycle operation may be performed.

  Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the various alternatives and modifications described above are within the scope of the present invention. Or a modification is included.

It is circuit explanatory drawing of a heat pump type water heater. It is a control block diagram. It is a front view of a muffler. It is AA sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Muffler 2A Small diameter part 2B Spherical part 2C Large diameter part 2H Muffler main body 2S1, 2S2 Connection piping 3 Refrigerant to water heat exchanger (heat exchanger for heating)
50 cover

Claims (4)

  A muffler body composed of a narrow diameter part at both ends, a spherical part expanded from each small diameter part into a substantially spherical shape, and a large diameter part between both spherical parts, and connected to both narrow diameter parts of the muffler body In a muffler comprising a connection pipe and attenuating pulsation of refrigerant discharged from the compressor, the muffler body and the connection pipe are made of copper, and the entire large diameter portion of the muffler body and at least both spherical portions A muffler characterized in that a part of it is covered with a stainless steel cover.   A muffler body composed of a narrow diameter part at both ends, a spherical part expanded from each small diameter part into a substantially spherical shape, and a large diameter part between both spherical parts, and connected to both narrow diameter parts of the muffler body In a muffler comprising a connection pipe and attenuating pulsation of refrigerant discharged from the compressor, the muffler body and the connection pipe are made of copper, and the entire large diameter portion of the muffler body and at least both spherical portions A muffler characterized in that a part of it is covered with a stainless steel cover so as to be in close contact with the outside.   The heat pump hot water heater is disposed between a compressor outlet side and a heating heat exchanger for exchanging heat between the refrigerant compressed by the compressor and water. 2. The muffler according to 2.   3. The muffler according to claim 1, wherein the muffler forms a part of a transcritical refrigerant cycle apparatus using a refrigerant whose high pressure side has a supercritical pressure. 4.

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