CN206207814U - Two-way thermostatic expansion valve and system including the same - Google Patents

Abstract

The utility model relates to a two-way thermal expansion valve, it includes valve body, case and unidirectional flow subassembly. The valve body has a valve seat, a first port and a second port. The valve core is accommodated in the valve body and is provided with an abutting part forming a throttling opening with the valve seat, and the valve core can move between a first position and a second position relative to the valve body, and in the first position, the abutting part abuts against the valve seat to close the throttling opening; in the second position, the abutment is away from the valve seat to open the orifice. The unidirectional flow assembly provides a flow path that communicates the first port and the second port and is configured to allow fluid flow from the first port to the second port and to prevent fluid flow from the second port to the first port. The utility model also provides a system including this two-way thermal expansion valve.

Description

Two-way thermostatic expansion valve and system including the same

technical field

The utility model relates to a two-way thermal expansion valve.

Background technique

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

The thermal expansion valve is a key component in the refrigeration system to control the superheat of the system, and is generally installed between the condenser and the evaporator. The thermal expansion valve realizes the pressure drop from the condensing pressure to the evaporating pressure, and regulates the flow of the refrigerant, thus directly determining the operating performance of the entire system.

The temperature sensing package is generally installed between the liquid storage cylinder (gas-liquid separator) and the evaporator. The thermal expansion valve senses the outlet temperature of the evaporator through a temperature sensing package to adjust the opening of the throttle, that is, to adjust the mass flow rate of the refrigerant flowing into the evaporator, and then adjust the outlet temperature of the evaporator to ensure the superheat of the refrigerant Stabilize and ensure that the gaseous refrigerant flows into the compressor, and realize the safe operation of the compressor under reasonable evaporation efficiency.

A known bidirectional thermal expansion valve includes a valve body and a valve core. The valve body is provided with a first port and a second port. A bi-directional thermal expansion valve allows refrigerant to flow in a first direction from a first port to a second port (which may be referred to as "forward flow") and in a second direction from the second port to the first port (which may be called "reverse flow"). The spool is accommodated in the valve body and is movable relative to the valve body between a closed position abutting against a valve seat on the valve body to close the expansion valve and an open position away from the valve seat to open the expansion valve.

A throttle port is formed between the valve core and the valve body. The outlet temperature of the evaporator sensed by the temperature sensing bulb can adjust the opening degree of the throttling port, thereby adjusting the mass flow rate of the refrigerant flowing through the throttling port.

Generally, the condition of forward flow of refrigerant is different from the condition of reverse flow of refrigerant. For example, the pressure difference between the first port and the second port is small under forward flow conditions, and the pressure difference between the first port and the second port is large under reverse flow conditions. In this example, when the opening of the orifice is constant, for example, when the orifice is at the rated opening or the maximum opening, the flow rate of the refrigerant flowing through the orifice under the condition of forward flow is relatively low. The flow rate of the refrigerant flowing through the orifice under the reverse flow condition is relatively large and thus its mass flow rate is relatively large. In short, the greater the difference between forward and reverse flow conditions, the greater the difference in refrigerant flow through the orifice. If the flow rate of the refrigerant flowing through the throttling port is too small, it will reduce the refrigeration capacity of the compressor, and even fail to meet the refrigeration requirements. Conversely, if the flow rate of refrigerant flowing through the orifice is too large, the refrigerant may not be fully evaporated in the evaporator, resulting in liquid refrigerant entering the compressor and causing liquid shock, reducing the efficiency of the compressor, or even damaging the compressor. mechanism.

Therefore, it is desired in the art to provide a two-way thermal expansion valve, which can meet the refrigerant flow requirements under both forward flow conditions and reverse flow conditions.

Utility model content

The purpose of the utility model is to provide a two-way thermal expansion valve optimized for two-way operation (forward flow operation and reverse flow operation).

Another object of the present invention is to provide a bidirectional thermal expansion valve with simplified structure and/or low cost.

According to one aspect of the present utility model, a two-way thermal expansion valve is provided, which includes: a valve body, a valve core and a one-way flow assembly. The valve body has a valve seat, a first port and a second port. The valve core is accommodated in the valve body and has an abutting portion forming a throttle port with the valve seat. The valve core can move between a first position and a second position relative to the valve body. In the first position, the abutting portion abuts against the valve seat to close the throttle; in the second position, the abutment part is away from the valve seat to open the throttle. The one-way flow assembly provides a flow path communicating the first port and the second port and is configured to allow fluid flow from the first port to the second port and prevent fluid flow from the second port to the first port.

For the two-way thermal expansion valve of the present invention, since the one-way flow assembly is provided, the flow rate of the working fluid (for example, refrigerant) under forward flow conditions or reverse flow conditions can be changed through the one-way flow components. Mass Flow. In this way, the structure and size of the one-way flow component can be designed according to the difference between the forward flow condition and the reverse flow condition, so that the bidirectional thermal expansion valve equipped with the one-way flow component can well meet the requirements of the forward flow condition. conditions and reverse flow conditions. In addition, the one-way flow assembly can be designed according to the specific structure of the two-way thermal expansion valve, so only minor changes are required to the existing thermal expansion valve, thereby greatly reducing manufacturing costs and assembly costs.

Optionally, said one-way flow assembly includes a flow channel forming said flow path and is disposed in said flow channel to allow fluid to flow through said flow channel in a direction from said first port to said second port. Channel check valve.

Optionally, the flow passage includes a passage formed in the spool. For example, the flow passage includes a passage provided in the abutment portion of the spool. The passages in the abutment are generally shorter in length. In this way, the processing difficulty can be reduced, and the stroke of the working fluid can be shortened to reduce the loss.

Optionally, the one-way valve is positioned adjacent to the passage in the spool.

Optionally, the one-way valve is a separate component and fixed to the end of the spool. In this way, the design of the one-way valve becomes flexible, and it is convenient to assemble and disassemble.

Optionally, the one-way valve includes a main body and a valve member defining a communication passage, the communication passage communicates with the passage in the valve core and defines a valve seat of the one-way valve, the valve member can resist Closed or opened by the valve seat or separated from the valve seat.

Optionally, the one-way valve further comprises an end cap retaining the valve member within the body.

Optionally, a biasing member is provided between the valve member and the end cap, the biasing member biasing the valve member towards a position closing the one-way valve. Optionally, the valve member is a spherical member, a conical member, an arc-shaped member or an annular member.

Optionally, the one-way valve is integrally formed in the flow path, and a part of the passage in the valve core constitutes a valve seat of the one-way valve against which a valve member can abut. Or be spaced from the valve seat to close or open the communication channel. Through this structure, the structure of the two-way thermal expansion valve of the present invention can be simplified and compacted.

Optionally, the one-way valve further includes an end cap for holding the valve member in the valve seat, and the valve member is a spherical member, a conical member, an arc-shaped member or a ring-shaped member.

Optionally, the one-way valve includes a reed for opening and closing the flow channel.

Optionally, the flow channel is formed in the material constituting the valve body. Optionally, the flow channel is formed outside the valve body, and the one-way valve is arranged outside or inside the valve body.

In another aspect of the present invention, a system comprising the above bi-directional thermal expansion valve is provided.

Description of drawings

The features and advantages of one or several embodiments of the present invention will become more easily understood from the following description with reference to the accompanying drawings, wherein:

Fig. 1 is a schematic diagram of refrigeration working conditions of a system using a bidirectional thermal expansion valve.

Fig. 2 is a schematic diagram of the heating working condition of the system using a bidirectional thermal expansion valve.

FIG. 3 is a schematic diagram of an example of the system shown in FIG. 1 operating in cooling mode.

FIG. 4 is a schematic diagram of an example of the system shown in FIG. 2 operating in a heating condition.

Fig. 5 is a longitudinal sectional view of the bidirectional thermal expansion valve according to the first embodiment of the present invention.

Fig. 6 is a cross-sectional view of the valve core of the two-way thermal expansion valve shown in Fig. 5 .

FIG. 7 is a cross-sectional view of the one-way flow assembly of the two-way thermal expansion valve shown in FIG. 5 .

8 is a cross-sectional view of the main body of the one-way flow assembly shown in FIG. 7 .

9 is a cross-sectional view of an end cap of the one-way flow assembly shown in FIG. 7 .

Fig. 10 is a longitudinal sectional view of a bidirectional thermal expansion valve according to a second embodiment of the present invention.

Fig. 11 is a cross-sectional view of the valve core and the one-way flow assembly shown in Fig. 10 .

Fig. 12 is a schematic diagram showing the fluid flow of the two-way thermal expansion valve under the cooling condition according to the present invention.

Fig. 13 is a schematic diagram showing the fluid flow of the two-way thermal expansion valve under the heating condition according to the present invention.

detailed description

The following descriptions of the preferred embodiments are only exemplary, rather than limiting the utility model and its application or use.

The directions of "up", "down", "top" and "bottom" mentioned in the following description are only relative to the orientation of the thermal expansion valve shown in the drawings, and can vary with the orientation of the thermal expansion valve. change in actual direction.

A system using a bidirectional thermal expansion valve and its working principle will be described below with reference to FIGS. 1 and 2 .

The system 10 shown in FIGS. 1 and 2 includes a compressor 11 , a four-way reversing valve 12 , a first heat exchanger (outdoor unit) 13 , a bidirectional thermal expansion valve 14 and a second heat exchanger (indoor unit) 15 . A filter 18 may be provided between the first heat exchanger 13 and the bidirectional thermal expansion valve 14 . A liquid storage tank (gas-liquid separator) 16 may be provided between the four-way reversing valve 12 and the compressor 11 upstream of the compressor 11 .

When the first heat exchanger 13 (in heating mode, as shown in Figure 2) or the second heat exchanger 15 (in cooling mode, as shown in Figure 1) and the liquid storage tank 16 or compressor 11 (without liquid storage) as an evaporator In the case of tanks), a temperature sensing package 17 can be arranged between them. The temperature sensing package 17 is used to sense the temperature of the fluid (refrigerant) coming out of the evaporator (the first heat exchanger 13 or the second heat exchanger 15), so as to determine the degree of superheat of the fluid, so as to transfer heat to the heat through the pipe 172. The expansion valve provides the corresponding pressure. in addition. The balance pipe 174 guides the refrigerant in the system 10 to the balance port of the two-way thermal expansion valve 14 . According to the difference between the pressure provided by the pipe 172 and the pressure of the refrigerant introduced through the balance pipe 174, the position of the spool of the two-way thermal expansion valve relative to the valve body is controlled, that is, the position of the abutting part of the control spool and the valve body The opening of the orifice between the valve seats. The degree of superheat of the refrigerant coming out of the evaporator is maintained within a predetermined range by controlling the opening degree of the orifice of the two-way thermal expansion valve.

FIG. 1 is a schematic diagram of the cooling operation of a system 10 employing a bi-directional thermal expansion valve. In the cooling condition, as shown in FIG. 1 , the compressor 11 discharges high-temperature and high-pressure gaseous refrigerant (working fluid), and the refrigerant enters the first heat exchanger 13 after passing through the four-way reversing valve 12 . The first heat exchanger 13 is used as a condenser under refrigeration conditions, and transfers the heat of the refrigerant to the surrounding environment to obtain liquid low-temperature and high-pressure refrigerant. Subsequently, the refrigerant flows into the two-way thermal expansion valve 14 through the filter 18, and expands into a low-temperature and low-pressure mist refrigerant after passing through its throttle port. The mist refrigerant discharged from the two-way thermal expansion valve 14 flows into the second heat exchanger 15 . The second heat exchanger 15 is used as an evaporator under cooling conditions, and the refrigerant absorbs heat in the evaporator and becomes gaseous so as to enter the compressor 11 for recirculation. During this process, the thermal expansion valve 14 adjusts thermal expansion based on the temperature (ie, degree of superheat) of the refrigerant discharged from the second heat exchanger 15 serving as an evaporator sensed by the temperature sensing bulb 17 . The opening of valve 14.

FIG. 2 is a schematic diagram of the heating operation of the system 10 using a bidirectional thermal expansion valve. By switching the four-way reversing valve 12 , the system 10 can be transformed from the cooling mode shown in FIG. 1 to the heating mode shown in FIG. 2 . In the heating condition, as shown in FIG. 2 , the compressor 11 discharges high-temperature and high-pressure gaseous refrigerant (working fluid), and the refrigerant enters the second heat exchanger 15 after passing through the four-way reversing valve 12 . The second heat exchanger 15 is used as a condenser under the heating condition, and transfers the heat of the refrigerant to the surrounding environment, thereby heating the surrounding environment. Subsequently, the refrigerant flows into the two-way thermal expansion valve 14, and expands into a low-temperature and low-pressure mist refrigerant after passing through its throttle port. The mist refrigerant discharged from the two-way thermal expansion valve 14 flows into the first heat exchanger 13 through the filter 18 . The first heat exchanger 13 is used as an evaporator under the heating condition, and the refrigerant absorbs heat in the evaporator and becomes gaseous so as to enter the compressor 11 for recirculation. In this process, the thermal expansion valve 14 adjusts the thermal expansion based on the temperature (ie, the degree of superheat) of the refrigerant discharged from the first heat exchanger 13 serving as an evaporator sensed by the temperature sensing bulb 17 . The opening of valve 14.

It can be known from the description with reference to FIG. 1 and FIG. 2 that the system 10 can realize both cooling and heating by means of the four-way reversing valve 12 and the two-way thermal expansion valve 14 . The refrigerant flows through the throttle port of the two-way thermal expansion valve 14 in opposite directions under cooling and heating conditions. The rated opening or the maximum opening of the orifice of the two-way thermal expansion valve 14 is the same under cooling and heating conditions.

Usually, the cooling and heating conditions of the system are quite different. When the opening degree of the orifice of the two-way thermal expansion valve is constant (for example, in the case of the rated opening or the maximum opening), the mass flow rate of the refrigerant flowing through the orifice of the two-way thermal expansion valve is in the refrigeration The working condition is obviously different from the heating working condition. When designing the system, usually the capacity of the thermal expansion valve is designed or selected to be optimal relative to the capacity of the condenser and evaporator under refrigeration conditions. However, in the heating condition, the above-mentioned design may cause poor matching between the capacity of the thermal expansion valve and the capacity of the condenser and evaporator, resulting in a decrease in efficiency or an increase in energy consumption of the entire system.

The difference between the two working conditions of the system will be described below by way of example with reference to FIG. 3 and FIG. 4 .

FIG. 3 is a schematic diagram of an example of the system shown in FIG. 1 operating in cooling mode. The bidirectional thermal expansion valve 14 has a first port 141 in fluid communication with the first heat exchanger 13 and a second port 142 in fluid communication with the second heat exchanger 15 . In the cooling condition shown in FIG. 3 , the refrigerant flows from the first port 141 to the second port 142 through the throttling port. The first heat exchanger 13 functions as a condenser on the outdoor side, and the second heat exchanger 15 functions as an evaporator on the indoor side. Suppose: the first heat exchanger 13 has a condensing temperature T1 of 50°C and a condensing pressure P1 of 267 psig; the second heat exchanger 15 has an evaporating temperature T2 of 10°C and an evaporating pressure P2 of 84 psig, then the difference between the condensing pressure and the evaporating pressure The value ΔP1 = P1 - P2 = 183 psig.

FIG. 4 is a schematic diagram of an example of the system shown in FIG. 2 operating in a heating condition. In the heating condition shown in FIG. 4 , the refrigerant flows from the second port 142 to the first port 141 through the throttling port. The first heat exchanger 13 functions as an evaporator on the outdoor side, and the second heat exchanger 15 functions as a condenser on the indoor side. Suppose: the second heat exchanger 15 has a condensing temperature T3 of 60°C and a condensing pressure P3 of 337 psig; the first heat exchanger 13 has an evaporating temperature T4 of -10°C and an evaporating pressure P4 of 37 psig, then the condensing pressure and the evaporating pressure The difference ΔP2 = P3 - P4 = 300 psig.

The pressure difference ΔP2 under the heating condition is significantly greater than the pressure difference ΔP1 under the cooling condition. When the opening degree of the orifice of the two-way thermal expansion valve 14 is constant, since the pressure difference ΔP2 is significantly greater than the pressure difference ΔP1, the mass flow rate of the refrigerant under the heating condition is significantly greater than that under the cooling condition. The mass flow rate of the agent. The greater the difference between the two working conditions, the greater the difference in the mass flow rate of the refrigerant.

The inventors have discovered the above-mentioned problems and proposed the present utility model based on the above-mentioned problems. The bidirectional thermal expansion valve according to the present invention will be described below with reference to accompanying drawings 5 to 13 .

Fig. 5 is a longitudinal sectional view of the bi-directional thermal expansion valve 100 according to the first embodiment of the present invention. As shown in FIG. 5 , the two-way thermal expansion valve 100 includes a valve body (valve casing) 110 and a valve core 130 accommodated in the valve body 110 . The valve body 110 has a valve seat 113 , and the valve core 130 has an abutting portion 133 abutting against or away from the valve seat 113 . The valve core 130 can move relative to the valve body 110 between a first position where the abutting portion 133 abuts against the valve seat 113 and a second position where the abutting portion 133 is away from the valve seat 113 . The orifice 120 is formed between the abutment portion 133 and the valve seat 113 . The abutment portion 133 closes the throttle port 120 when abutting against the valve seat 113 so as to prevent the refrigerant from flowing through the throttle port 120 . The abutting portion 133 opens the throttle port 120 when moving away from the valve seat 113 to allow refrigerant to flow through the throttle port 120 .

The valve body 110 is further provided with a first port 111 and a second port 112 respectively located on two sides of the throttle port 120 . In connection with the system shown in FIG. 1 , the first port 111 may be in fluid communication with the first heat exchanger 13 and the second port 112 may be in fluid communication with the second heat exchanger 15 . In the cooling condition, the refrigerant flows from the first port 111 to the second port 112 through the orifice 120 (which may be referred to as “forward flow”). In the heating condition, the refrigerant flows from the second port 112 to the first port 111 through the orifice 120 (which may be referred to as “reverse flow”).

The bi-directional thermal expansion valve 100 according to the present invention also includes a one-way flow component 150 . The one-way flow assembly 150 is configured to allow refrigerant to flow from one of the first port 111 and the second port 112 to the other but prevent refrigerant from flowing from the other of the first port 111 and the second port 112 . flow to the one. In short, the one-way flow assembly 150 allows refrigerant to flow in only one direction between the first port 111 and the second port 112 .

As an example shown in FIG. 5 , the one-way flow assembly 150 is configured to allow refrigerant to flow from the first port 111 to the second port 112 but prevent refrigerant from flowing from the second port 112 to the first port 111 . In this way, under cooling conditions, while the refrigerant flowing into the first port 111 flows to the second port 112 through the throttle port 120 , the refrigerant can also flow from the first port through the additional flow path provided by the one-way flow component 150 . 111 flows to the second port 112, as shown in FIG. 12, thereby providing a larger flow cross-section. In the heating condition, the refrigerant flowing into the second port 112 only flows to the first port 111 through the throttle port 120, but cannot flow to the first port 111 through the one-way flow assembly 150 (at this time, the one-way flow The additional flow path provided by assembly 150 is closed), as shown in Figure 13, thereby providing a smaller flow cross-section.

Compared with the existing two-way thermal expansion valve without a one-way flow component, the two-way thermal expansion valve 100 shown in FIG. The cooling capacity (refrigerating capacity) and cooling efficiency of the system including the two-way thermal expansion valve can be increased greatly. In this way, when the capacity of the thermal expansion valve is designed or selected to be optimal relative to the capacity of the condenser and evaporator under refrigeration conditions (at this time, the pressure difference experienced by the thermal expansion valve Smaller, but the flow section provided is larger, so as to provide a predetermined cooling capacity overall), in the heating condition, the capacity of the thermal expansion valve can also form a better match with the capacity of the condenser and evaporator (at this time , the pressure difference experienced by the thermal expansion valve is larger, but the flow section provided is smaller, so that it can also provide the desired cooling capacity in general). In addition, by designing the cross-sectional area of the additional flow path provided by the one-way flow assembly 150, it is possible to optimize both the heating condition and the cooling condition of the system at the same time to obtain optimal performance under both conditions. system efficiency. In particular, in addition, by designing the cross-sectional area of the additional flow path provided by the one-way flow assembly 150, the system can be easily adapted to eg southern or northern climates and obtain good system efficiency.

Additional flow paths provided by the one-way flow assembly may be formed within and/or outside the valve body (casing). For example, a one-way flow assembly may include a conduit fluidly connecting a first port to a second port, and the separate conduit may be located entirely outside the valve body (i.e., the entire flow path is outside the valve body), or may be entirely inside the valve body (i.e., the entire The flow path is inside the valve body), or a part may be outside the valve body and the other part is inside the valve body (that is, the entire flow path includes a part outside the valve body and a part inside the valve body).

The one-way flow assembly includes a flow channel forming a flow path and a one-way valve disposed in the flow path to allow fluid to flow through the flow channel in a direction from the first port to the second port. The flow passage may include a passage formed in one or more components of the thermal expansion valve (eg, the valve body or spool). The one-way valve may be a separate piece and connected in the flow path, or the one-way valve may be integrally formed in the flow path.

An example of the two-way thermal expansion valve according to the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the two-way thermal expansion valve of the present invention is not limited to the illustrated example, and the illustrated example is only for illustrative purposes.

5 to 9 show a bi-directional thermal expansion valve 100 and its components according to the first embodiment of the present invention. As shown in FIG. 5 , the one-way flow assembly 150 includes a passage 134 disposed in the abutting portion 133 of the spool 130 and a one-way valve 152 adjacent to the passage 134 . The one-way valve 152 includes a main body 151 and a valve member 152 a provided in the main body 151 . The main body 151 defines a valve seat 152b. The valve member 152a is movable between a closed position against the valve seat 152b to close the passageway 134 and an open position away from the valve seat 152b to open the passageway 134 .

A one-way valve 152 is installed at an end (lower end as shown in FIG. 6 ) 135 of the spool 130 adjacent to the second port 112 . The one-way valve 152 includes a recess 155 (shown in FIGS. 7 and 8 ) that receives the end 135 of the spool 130 . The end 135 of the spool 130 may be an interference fit in the recess 155 of the one-way flow assembly 150 , thereby securing the one-way flow assembly 150 to the spool 130 . As shown in Figure 6. After the one-way valve 152 is assembled to the spool 130, the one-way valve 152 directly abuts against the abutting portion 133 of the spool 130, and the communication channel 154 of the one-way valve 152 is aligned with the passage 134 of the abutting portion 133 and connected. As such, the first port 111 is in fluid communication with the second port 112 via the passage 134 and the communication channel 154 .

In the illustrated example, the one-way valve 152 is configured to allow refrigerant to flow from the first port 111 to the second port 112 but prevent refrigerant from flowing from the second port 112 to the first port 111 . The check valve 152 is located on the downstream side of the communication passage 154 in the forward flow direction (flow direction from the first port 111 to the second port 112 ).

Although the one-way valve 152 is installed at the lower end portion 135 of the spool 130 in the illustrated example, the one-way valve 152 may be installed at any suitable location as long as the one-way valve 152 can perform the above-mentioned functions. For example, the one-way valve 152 can be installed on the outside of the valve body 110, or can be installed in the valve body 110, or can be installed at other positions on the valve core except the lower end, depending on the one-way flow assembly 150 The provided flow path settings.

In the illustrated example, the valve member 152 a has a circular cross-section and is housed in the body 151 of the one-way flow assembly 150 . Correspondingly, the main body 151 of the one-way flow assembly 150 is provided with an accommodating portion 157 for accommodating the valve member 152a. In the illustrated example, the accommodating portion 157 has a tapered cross-section. The valve seat 152b may be formed on the accommodating portion 157 , may be formed on a transition portion of the accommodating portion 157 and the communication passage 154 , or may be formed on an end of the communication passage 154 .

In the cooling condition, the one-way valve 152 is in an open state, and the refrigerant from the first port 111 flows through the passage 134 and the communication passage 154 and flows to the second port 112 through the one-way valve 152 . In the heating condition, the high pressure of the refrigerant from the second port 12 acts on the valve member 152a of the one-way valve 152, so that the valve member 152a moves toward the communication passage 154 to abut against the valve seat 152b to close the communication passage 154, And prevent the refrigerant from flowing from the second port 112 to the first port 111 through the passage 134 .

The communication channel 154 may be in the form of a circular hole, an arc-shaped groove or an annular groove. Accordingly, the valve member 152a may be a spherical member (as shown), a conical member, an arcuate member, or an annular member. In addition, the quantity, shape and structure or relative positions of the communication passage 154 and the one-way valve 152 can be changed according to actual needs. In other examples, the one-way valve may be a reed located at the end of the flow channel, or any other member capable of performing the functions described above.

The one-way flow assembly 150 may also include an end cap 156 . An end cap 156 is located on the underside of the one-way valve 152 . The valve member 152 a is movable between the end cap 156 and the communication passage 154 . End cap 156 may be configured to prevent valve member 152a from falling and allow refrigerant to flow from one-way flow assembly 150 when one-way valve 152 is open. End cap 156 may include a recess 159 that receives boss 153 of body 151 . Boss 153 may be an interference fit in recess 159 .

In other examples, the end cap may have a recess for directly receiving the lower end 135 of the spool 130 . The lower end 135 of the spool 130 may be an interference fit in the recess, thereby clamping the body of the one-way flow assembly between the end cap and the abutment. In such an example, the boss 153 of the body 151 of the one-way flow assembly 150 may be omitted. The position, structure or size of the end cap can be changed according to actual needs.

Optionally, the main body 151 and the end cap 156 of the one-way flow assembly 150 may be provided with through holes 158a and 158b for introducing the refrigerant at the side of the second port 112 to the upper part of the valve core to achieve pressure balance. The structures of the various components of the one-way flow assembly 150 may vary according to the structural changes of the valve body and the valve core.

In other examples, the one-way flow assembly may include a biasing member that biases the valve member of the one-way valve toward the flow passage. The biasing member may be disposed between the valve member and the end cap. The biasing member may be a compression spring.

Fig. 10 is a longitudinal sectional view of a bidirectional thermal expansion valve 200 according to a second embodiment of the present invention. Fig. 11 is a cross-sectional view of the valve core and the one-way flow assembly shown in Fig. 10 . The difference between the two-way thermal expansion valve of the second embodiment and the two-way thermal expansion valve of the first embodiment is only that: in the second embodiment, the main body of the one-way valve and the valve core are formed as one piece.

As shown in FIGS. 10 and 11 , the abutting portion 233 of the two-way thermal expansion valve 200 also serves as the main body of the one-way flow assembly 250 . A passage 234 is provided in the abutting portion 233 . On the lower side of the passage 234, a valve member 252a of the check valve 252 is provided. In this example, the passage 234 is equivalent to the passage 134 and the communication channel 154 in the example shown in FIG. 5 . A portion of the passage 234 in the spool may constitute the valve seat 252b of the one-way valve. The valve member 252a can abut against the valve seat 252b or be spaced apart from the valve seat 252b to close or open the passage (or communication passage). An end cap 256 is provided on the lower side of the one-way valve 252 for interference fit with the lower end of the valve core (or fixed in any other suitable manner, such as threaded connection, riveting, bonding, welding, snap-fitting, etc.).

Although various embodiments of the present utility model have been described in detail here, it should be understood that the present utility model is not limited to the specific embodiments described and shown in detail here, and can be made by Other modifications and variations will occur to those skilled in the art. All such modifications and variations fall within the scope of the present invention. Moreover, all components described here may be replaced by other technically equivalent components.

Claims (16)

1. A two-way thermal expansion valve, characterized in that it comprises: a valve body (110) having a valve seat (113), a first port (111) and a second port (112); a spool (130, 230), the spool (130, 230) is accommodated in the valve body (110) and has an abutment portion ( 133, 233), the valve core (130, 230) can move relative to the valve body (110) between a first position and a second position, in the first position, the abutting portion (133 , 233) against the valve seat (113) to close the throttle port (120); in the second position, the abutment portion (133, 233) is away from the valve seat (113) to open said orifice (120); and a one-way flow assembly (150, 250) that provides a flow path communicating the first port (111) and the second port (112) and is configured to allow fluid from The first port (111) flows to the second port (112) and fluid is prevented from flowing from the second port (112) to the first port (111). 2. The two-way thermal expansion valve according to claim 1, characterized in that, the one-way flow assembly (150, 250) includes a flow channel forming the flow path and is arranged in the flow channel to allow the fluid to flow along A one-way valve (152, 252) of the flow channel for flow in the direction from the first port (111) to the second port (112). 3. The bi-directional thermal expansion valve according to claim 2, characterized in that the flow channel comprises a passage formed in the valve core (130, 230). 4. The two-way thermal expansion valve according to claim 2, characterized in that the flow channel comprises a passage (134, 234) provided in the abutment portion (133) of the valve core. 5. The bi-directional thermal expansion valve of claim 4, wherein the one-way valve (152, 252) is positioned adjacent to the passage (134, 234) in the spool. 6. The bi-directional thermal expansion valve according to claim 5, characterized in that the one-way valve (152) is a separate component and fixed to the end of the valve core. 7. The bidirectional thermal expansion valve according to claim 5, characterized in that, the one-way valve (152) comprises a main body (151) and a valve member (152a) defining a communication channel (154), the communication channel (154) communicates with the passage (134) in the spool and defines a valve seat (152b) of the one-way valve against which the valve member (152a) can abut or with the The valve seat (152b) is spaced to close or open the communication passage (154). 8. The bi-directional thermal expansion valve according to claim 7, characterized in that the one-way valve (152) further comprises an end cap (156) holding the valve member (152a) in the main body (151 ). 9. The two-way thermal expansion valve according to claim 8, characterized in that, a biasing member is provided between the valve member (152a) and the end cap (156), and the biasing member divides the A valve member (152a) is biased toward a position closing the one-way valve. 10. The two-way thermal expansion valve according to claim 8, characterized in that, the valve member (152a) is a spherical member, a conical member, an arc-shaped member or an annular member. 11. The two-way thermal expansion valve according to claim 5, characterized in that, the one-way valve (252) is integrally formed in the flow path, and the passage (234) in the valve core A part constitutes a valve seat (252b) of the one-way valve, and a valve member (252a) can abut against the valve seat (252b) or be spaced from the valve seat (252b) to close or open the communication passage (154 ). 12. The two-way thermal expansion valve according to claim 11, characterized in that, the one-way valve (252) further comprises an end cap ( 256), the valve member (252a) is a spherical member, a conical member, an arc-shaped member or an annular member. 13. The bidirectional thermal expansion valve according to any one of claims 2 to 6, wherein the one-way valve comprises a reed for opening and closing the flow channel. 14. The two-way thermal expansion valve according to claim 2, characterized in that, the flow channel is formed in the material constituting the valve body (110). 15. The two-way thermal expansion valve according to claim 2, characterized in that, the flow channel is formed outside the valve body (110), and the one-way valve is arranged outside or inside the valve body. 16. A system comprising a bi-directional thermal expansion valve according to any one of claims 1 to 15.