Multifunctional reservoir for a secondary circuit climate control system and secondary circuit climate control system including the multifunctional reservoir

Abstract

The present disclosure provides a "multifunctional reservoir for a secondary loop climate control system and a secondary loop climate control system including the multifunctional reservoir". The multifunctional reservoir for a secondary loop climate control system includes a coolant container, a compartment held in the coolant container, and a phase change material in the compartment. A secondary loop air conditioning system and a secondary loop heat pump system including one or more multifunctional reservoirs of the type described are also disclosed.

Description

Technical Field

[0001] The present document relates generally to the field of climate control and more particularly to a multifunctional reservoir for a secondary loop climate control system and a secondary loop climate control system comprising the multifunctional reservoir and suitable, for example, in a motor vehicle. The secondary loop climate control system comprises a secondary loop air conditioning system and a secondary loop heat pump system. Background Art

[0002] This document relates to a new and improved multifunctional reservoir for a secondary loop climate control system, such as a secondary loop air conditioning system or a secondary loop heat pump system. The multifunctional reservoir comprises a compartment containing a phase change material (PCM). Thus, the multifunctional reservoir provides a coolant storage function, a surge chamber function for preventing pressure spikes, an air ventilation function, and now a heat storage function without adding a separate component with a dedicated heat storage function to the climate control system. Summary of the invention

[0003] In accordance with the objects and benefits described herein, a new and improved multi-function reservoir for a secondary loop climate control system is provided. The multi-function reservoir includes a coolant container, one or more compartments held in the coolant container, and a PCM contained in each compartment.

[0004] The multifunctional reservoir also includes an inlet port and an outlet port on the coolant container. In addition, the multifunctional reservoir may also include a modulation function feature at one of the inlet port and the outlet port to allow adjustment of the coolant flow rate. The modulation function feature may be a pulse width modulation solenoid valve.

[0005] The PCM disposed in the cabin may be essentially any phase change material suitable for the intended heat storage purpose of the secondary loop climate control system. Depending on the temperature range over which the phase change occurs, PCMs may be divided into three main groups: a) low temperature materials with a phase change temperature below 15 degrees Celsius, such as in air conditioning applications, b) medium temperature materials with a phase change temperature between 15 and 90 degrees Celsius, such as in solar or heat pump applications, and c) high temperature materials with a phase change temperature above 90 degrees Celsius, such as in aerospace applications. The low temperature PCM may be a salt hydrate such as LiClO 3 ·3H 2 O; or paraffins, such as n-tetradecane (14 carbon paraffin) and n-pentadecane (15 carbon paraffin). The medium temperature PCM can also be a salt hydrate, such as CaCl 2 6H 2 O; or paraffins, such as n-docosane (22 carbon paraffin) and n-octacosane (28 carbon paraffin). The high temperature PCM can be an inorganic compound, such as AlCl 3or NaNO 3 .

[0006] The cabin comprises an outer wall preferably made of a thermally conductive and stable material. For example, the material can be selected from a group of metallic materials, such as aluminum, copper, stainless steel and carbon steel.

[0007] According to another aspect, a secondary loop air conditioning system is provided. The secondary loop air conditioning system includes a refrigerant circuit adapted to circulate refrigerant between a compressor, a condenser, an expansion device, and a cryocooler, and a coolant circuit adapted to circulate coolant between the cryocooler, a pump, a first cooler, and a reservoir having an integrated phase change material feature.

[0008] The reservoir may include a coolant container, and the PCM feature may include at least one compartment held in the coolant container and a PCM contained in each compartment.

[0009] The secondary loop air conditioning system may also include an inlet port and an outlet port in the coolant container, and a regulating function feature at one of the inlet port and the outlet port to regulate the coolant flow rate. The modulation function feature may be implemented by a pulse width modulation solenoid valve. The PCM may be essentially any phase change material suitable for cryogenic applications, such as 14 carbon paraffin. The cabin may include an outer wall, which is preferably made of a thermally conductive and stable material, such as a metallic material such as aluminum, copper, stainless steel and carbon steel.

[0010] The secondary loop air conditioning system may also include a second cooler in the coolant loop. The two coolers may provide air conditioning functions for two different areas of the motor vehicle.

[0011] According to another aspect, a secondary circuit heat pump system is provided. The secondary circuit heat pump system includes a first four-way valve, a second four-way valve, a cooling circuit connected to the first four-way valve and the second four-way valve, and a heating circuit connected to the first four-way valve and the second four-way valve. The cooling circuit includes a cold source, a first reservoir, a first heat exchanger and a first pump. The heating circuit includes a heat source, a second reservoir, a second heat exchanger and a second pump. The first reservoir in the cooling circuit includes a first phase change material feature. The second reservoir in the heating circuit includes a second phase change material feature.

[0012] The first reservoir may include a first coolant container. The first phase change material feature may include a first compartment held in the first coolant container and a first phase change material contained in the first compartment. The second reservoir may include a second coolant container. The second phase change material feature may include a second compartment held in the second coolant container and a second phase change material contained in the second compartment. The first phase change material may be a low temperature PCM, such as 14 carbon paraffin. The second phase change material may be a medium temperature PCM, such as 28 carbon paraffin.

[0013] In the following description, several preferred embodiments of a multifunctional reservoir, a secondary circuit air conditioning system including the multifunctional reservoir, and a secondary circuit heat pump system also including the multifunctional reservoir are shown and described. It should be appreciated that the multifunctional reservoir, the secondary circuit air conditioning system, and the secondary circuit heat pump system are capable of other different embodiments, and that their several details are capable of modification in all various obvious respects without departing from the multifunctional reservoir, the secondary circuit air conditioning system, and the secondary circuit heat pump system as illustrated and described in the following claims. Therefore, the drawings and description should be regarded as illustrative in nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings included herein and forming a part of the specification illustrate several aspects of the multi-function reservoir, secondary loop air conditioning system and secondary loop heat pump system and, together with the description, serve to explain certain principles of the multi-function reservoir, secondary loop air conditioning system and secondary loop heat pump system.

[0015] Figure 1 is a schematic diagram of a multi-function reservoir suitable for use in a secondary loop climate control system, such as a secondary loop air conditioning system or a secondary loop heat pump system.

[0016] Figure 2 is a schematic diagram of a compartment insert for a multi-purpose reservoir.

[0017] Figure 3 is included Figure 1 Schematic perspective view of a secondary circuit air conditioning system with a multifunctional reservoir of the type shown.

[0018] Figure 4 It contains two Figure 1 Schematic block diagram of a secondary circuit heat pump system with a multifunctional reservoir of the type shown, the two Figure 1 Multifunctional reservoirs of the type shown are a first multifunctional reservoir which is arranged in the cold coolant circuit and a second multifunctional reservoir which is arranged in the hot coolant circuit.

[0019] Figure 5aShows operation in cooling mode Figure 4 Secondary circuit heat pump system.

[0020] Figure 5b Shown operating in heating mode Figure 4 Secondary circuit heat pump system.

[0021] Figure 5c Shows operation in dehumidification and reheating mode Figure 4 Secondary circuit heat pump system.

[0022] Reference will now be made in detail to preferred embodiments of the present invention of a multi-function reservoir, a secondary loop air conditioning system and a secondary loop heat pump system, examples of which are illustrated in the accompanying drawings. DETAILED DESCRIPTION

[0023] Reference now Figure 1 , Figure 1 A new and improved multi-function reservoir 10 is schematically shown. The multi-function reservoir 10 is particularly suitable for use in secondary circuit climate control systems, such as Figure 3 The secondary circuit air conditioning system 12 is shown, and Figure 4 and Figure 5a to Figure 5c A secondary circuit heat pump system 14 is shown.

[0024] like Figure 1 As shown, the multi-function reservoir 10 includes a coolant container 16 formed of any suitable material suitable for holding the coolant C of the climate control system while resisting corrosion and providing reliable operation over an extended service life in a motor vehicle environment. The multi-function reservoir 10 also includes a compartment 18 retained within a coolant chamber 20 of the coolant container 16. A phase change material 22 is disposed within the compartment 18.

[0025] More specifically, the phase change material 22 can be any PCM suitable for the climate control system environment, including, for example, paraffin or salt hydrate. The material can be selected depending on the operating conditions of the climate control system and the phase change temperature of the PCM. For example, 14 carbon paraffin has a phase change temperature of about 6 degrees Celsius and is suitable for use in a multifunctional reservoir 10 utilized in a cold coolant loop of a secondary loop climate control system. In contrast, 28 carbon paraffin has a phase change temperature of about 61 degrees Celsius, which makes it suitable for use in a multifunctional reservoir 10 used in a hot coolant loop of a secondary loop climate control system. The cabin 18 includes an outer wall 24, which is preferably made of a material that is heat-conductive, stable, and resistant to corrosion from the coolant C held in the coolant container 16 and the phase change material 22 held in the cabin. For example, the outer wall 24 can be made of a metal material, such as aluminum, copper, stainless steel, and carbon steel.

[0026] Figure 1 The illustrated multi-function reservoir 10 includes a single compartment 18 that holds a phase change material 22. It should be noted here that more than one compartment 18 may be provided in the coolant chamber 20 of the coolant container 16. Figure 2 A multi-compartment insert 30 is shown that includes three compartments 32, each of which holds a phase change material 22. The three compartments 32 are all secured to a support or base 33 to maintain spacing between the compartments 32 to accommodate the flow of coolant C between and around the compartments for the most efficient heat exchange. As will be appreciated, the multi-compartment insert 30 may be substituted for Figure 1 The illustrated compartment 18. It should also be noted here that the heat exchange material provided in each compartment of the compartment 32 may be the same, or may be different, having different phase change temperatures. The PCM selected for each compartment of the compartment 32 is the product of the design parameters and performance requirements required for the secondary loop climate control system to adapt to a given application.

[0027] like Figure 1 As further shown in FIG. 1 , the multi-function reservoir 10 includes an inlet port 34 and an outlet port 36 for circulating coolant C in and out of the coolant container 16. In the illustrated embodiment, the inlet port 34 is disposed near the centerline of the coolant container 16, while the outlet port 36 is disposed near the bottom 17 of the container.

[0028] The modulation function feature 38 may be provided at one of the inlet port 34 and the outlet port 36 to adjust the coolant flow rate. In the illustrated embodiment, the modulation function feature 38 is provided in the outlet port 36. The modulation function feature 38 may take the form of a flow control valve of any suitable structure, including, for example, a pulse width modulated solenoid valve, thereby allowing the adjustment of the coolant flow rate from the multi-function reservoir 10 to be achieved via frequency control or position control. More specifically, a correlation may be established between the frequency (or opening) of the valve and the coolant flow rate and the desired flow rate determined by the required heat exchanger capacity, heat exchanger geometry, air inlet conditions, and coolant inlet conditions.

[0029] Reference now Figure 3 , Figure 3 A secondary loop air conditioning system 12 is shown. The secondary loop air conditioning system 12 includes a refrigerant circuit 40 adapted to circulate a refrigerant such as R134a, R1234yf, R152a or R744 (CO 2 ). Action arrows A show the circulation of refrigerant by the compressor 42 through the refrigerant circuit 40 .

[0030] The secondary loop air conditioning system 12 also includes a coolant circuit 50 adapted to be connected between the cryocooler 48, the pump 52, the primary cooler 54, and the secondary loop air conditioning system 12. Figure 1 A reservoir 56 of the type shown having an integrated phase change material feature 57 circulates a coolant, such as a mixture of ethylene glycol and water or a mixture of propylene glycol and water, between the reservoirs 56 , such as the chamber 18 containing the phase change material 22 . Action arrows B show the circulation of refrigerant by the pump 52 through the coolant circuit 50 .

[0031] More specifically, the refrigerant is compressed into a high-temperature, high-pressure vapor in the compressor 42 and enters the condenser 44, where the refrigerant is cooled into a low-temperature, high-pressure refrigerant, preferably a pure liquid, by heat exchange with the ambient air circulating over the condenser. The resulting low-temperature, high-pressure refrigerant leaving the condenser 44 passes through an expansion device 46, which expands the refrigerant into a low-temperature, low-pressure gas-liquid mixture. The refrigerant mixture then evaporates in the cryocooler 48 due to heat absorption from the coolant circulating in the coolant loop 50, and leaves as a low-temperature, low-pressure vapor. The low-temperature, low-pressure refrigerant vapor then returns to the compressor 42 to start the refrigerant cycle again.

[0032] In the coolant loop 50, coolant from the reservoir 56 is pumped by the pump 52 to the cryocooler 48 to exchange heat with the refrigerant. Heat is transferred from the coolant to the refrigerant in the cryocooler 48. The cooled coolant discharged from the cryocooler 48 is delivered to the cooler 54. Air circulating through the heating, ventilation and air conditioning (HVAC) housing 58 of the air conditioning system is in heat exchange relationship with the coolant in the cooler 54. Therefore, the cooled air circulates into the passenger compartment of the motor vehicle. After exchanging heat with the air, the coolant is discharged from the cooler 54 and returned to the reservoir 56 including the integrated phase change material feature 57. It should be understood here that the reservoir 56 provides four separate functions: (1) coolant storage, (2) a surge chamber function to prevent pressure spikes in the coolant circuit, (3) a vent function to vent air bubbles in the coolant circuit to the external environment, and (4) heat storage via heat exchange with the phase change material 22 of the integrated phase change material feature 57.

[0033] Where the reservoir 56 includes the modulation feature 38 , the coolant flow rate from the reservoir 56 to the pump 52 may be controlled in a desired manner.

[0034] Reference now Figure 4 , Figure 4 One possible embodiment of a secondary loop heat pump system 14 is shown. The secondary loop heat pump system 14 includes a first four-way valve 60, a second four-way valve 62, a cooling circuit 64, and a heating circuit 66.

[0035] More specifically, the cooling circuit 64 is arranged to communicate with the first four-way valve 60 and the second four-way valve 62. In addition, the cooling circuit 64 includes a cold source 68, such as a cryocooler of a refrigerant circuit; a first reservoir 70, which can be connected to Figure 1 The multifunctional reservoir 10 shown is the same as the one shown; a first heat exchanger 72 for providing heat exchange between the coolant in the cooling circuit 64 and the air circulated through the passenger compartment of the motor vehicle; and a first pump 74. A heating circuit 66 is also provided in communication with the first four-way valve 60 and the second four-way valve 62. The heating circuit 66 includes a heat source 76 for heating the coolant; a second reservoir 78, which can be connected to Figure 1 The multifunctional reservoir 10 shown is identical; a second heat exchanger 80 for exchanging heat between the coolant and air circulated through the passenger compartment of the motor vehicle; and a second pump 82 for circulating the coolant through the heating circuit 66. An integrated phase change material feature 83 provided in the first reservoir 70 of the cooling circuit 64 contains a low temperature PCM suitable for the cooling circuit. Such a phase change material may be, for example, 14 carbon paraffin. In contrast, the second reservoir 78 in the heating circuit 66 includes an integrated phase change material feature 85 having a medium temperature PCM suitable for the heating circuit, such as 28 carbon paraffin.

[0036] Figure 5a The operation of the secondary loop heat pump system 14 in the cooling mode is shown. As shown, the first pump 74 pumps the coolant from the first reservoir 70 to the cold source 68 to remove heat from the coolant, and then the coolant is pumped from the cold source through the first four-way valve 60 to the first heat exchanger 72. There, heat is removed from the air circulating into the passenger compartment to provide the required cooling for the motor vehicle occupants. The warmed coolant is then pumped back to the first reservoir 70 through the second four-way valve 62, thus completing one cycle through the cooling circuit 64. The coolant continues to move through the cooling circuit 64 in this manner (note the action arrow C) until the cooling mode is terminated.

[0037] Reference now Figure 5b , Figure 5bThe operation of the secondary loop heat pump system 14 in the heating mode is shown. More specifically, the coolant from the second reservoir 78 is pumped by the second pump 82 to the heat source 76 for heat exchange. The heated coolant then travels from the heat source 76 through the second four-way valve 62 to the second heat exchanger 80, where the coolant exchanges heat with the air circulating through the passenger compartment of the motor vehicle. As a result, the air is heated to warm the passengers in the passenger compartment. The coolant discharged from the second heat exchanger 80 is pumped by the pump 82 through the first four-way valve 60 and then returned to the second reservoir 78, thereby completing a complete cycle of the heating circuit 66. This movement of the coolant continues in this manner (note the action arrow D) until the heating mode is terminated.

[0038] Reference now Figure 5c , Figure 5c The operation of the secondary loop heat pump system 14 in the dehumidification and reheating modes is shown. Figure 5a The coolant moves through the cooling circuit 64 in the same manner as described above with respect to the cooling mode (note the action arrow C), and the coolant moves in the same manner as described above with respect to the cooling mode in FIG. Figure 5b The air is moved through the heating circuit 66 in the same manner as described above for the heating mode (note the action arrow D). Therefore, the air directed into the passenger compartment of the motor vehicle first comes into heat exchange contact with the first heat exchanger 72. At this point, the air is cooled and dehumidified. Next, the air passes through the second heat exchanger 80 in a heat exchange relationship. Therefore, the air is heated to provide dry and warm comfort for the passengers in the passenger compartment. Such air can be used in particular for defogging or deicing windshields.

[0039] The multifunctional reservoir 10, secondary loop air conditioning system 12, and secondary loop heat pump system 14 described herein provide many benefits and advantages. The multifunctional reservoir 10 integrates the phase change material features 57, 83, 85 into the secondary loop system, and more specifically into the reservoirs 56, 70, 78 of the secondary loop system, without introducing new separate components into the system. Thus, the multifunctional reservoir 10, 56, 70, 78 not only provides traditional coolant storage and surge chamber functions, but also allows and provides heat storage to provide better comfort and climate control system operation under essentially any foreseeable operating conditions. Where the multifunctional reservoir 10 includes the modulation function feature 38, it is possible to fully control the coolant flow while utilizing a fixed speed coolant pump 52, 74, 82 and also eliminating the need for shutoff valves in the loop.

[0040] Figure 4The secondary loop heat pump system 14 shown in FIG. 1 includes a first reservoir 70 having an integrated phase change material feature 83 and a second reservoir 78 having an integrated phase change material feature 85 , thereby providing more effective and efficient operation of both the cooling loop 64 and the heating loop 66 .

[0041] The foregoing description has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. In view of the above teachings, obvious modifications and variations are possible. For example, the cabin 18 may be provided in any desired shape and may be provided in any desired number. The four-way valves 60, 62 may be replaced by a plurality of one-way valves, two-way valves, or three-way valves. All such modifications and variations are within the scope of the appended claims when interpreted in accordance with the scope to which they are reasonably, legally, and equitably entitled.

[0042] According to the present invention, a multifunctional reservoir for a secondary loop climate control system is provided, the multifunctional reservoir being configured to have: a coolant container; a compartment; the compartment being held in the coolant container; and a phase change material, the phase change material being in the compartment.

[0043] According to one embodiment, the above invention also features an inlet port and an outlet port on the coolant container.

[0044] According to one embodiment, the above invention also features a modulation function feature at one of the inlet port and the outlet port to adjust the coolant flow rate.

[0045] According to one embodiment, the modulating functional feature is a pulse width modulated solenoid valve.

[0046] According to one embodiment, the phase change material has a phase change temperature below 15 degrees Celsius for the cooling circuit and a phase change temperature between 15 and 90 degrees Celsius for the heating circuit.

[0047] According to one embodiment, the phase change material is selected from a first group of materials consisting of paraffin wax or salt hydrate.

[0048] According to one embodiment, the cabin comprises an outer wall made of a second group of metallic materials, said second group of metallic materials consisting of aluminum, copper, stainless steel and carbon steel.

[0049] According to the present invention, a secondary circuit air conditioning system is configured to have: a refrigerant circuit adapted to circulate refrigerant between a compressor, a condenser, an expansion device and a cryocooler; and a coolant circuit adapted to circulate coolant between a cryocooler, a pump, a primary cooler and a reservoir having an integrated phase change material feature.

[0050] According to one embodiment, the reservoir includes a coolant container, and the integrated phase change material feature includes a compartment held in the coolant container and a phase change material in the compartment.

[0051] According to one embodiment, the above invention also features an inlet port and an outlet port in the coolant container, and a regulating function feature at one of the inlet port and the outlet port to regulate the coolant flow rate.

[0052] According to one embodiment, the above invention is further characterized in that the modulation function feature is a pulse width modulation solenoid valve.

[0053] According to one embodiment, the phase change material has a phase change temperature below 15 degrees Celsius.

[0054] According to one embodiment, the phase change material is selected from a first group of materials consisting of paraffin wax or salt hydrate.

[0055] According to one embodiment, the cabin comprises an outer wall made of a material selected from a second group of metallic materials consisting of aluminum, copper, stainless steel and carbon steel.

[0056] According to one embodiment, the above invention is also characterized in that a second cooler in the coolant circuit is used to provide air conditioning functions to two different areas of the motor vehicle.

[0057] According to the present invention, a secondary circuit heat pump system is provided, which has: a first four-way valve; a second four-way valve; a cooling circuit, which is connected to the first four-way valve and the second four-way valve, and the cooling circuit includes a cold source, a first reservoir, a first heat exchanger and a first pump; and a heating circuit, which is connected to the first four-way valve and the second four-way valve, and the heating circuit includes a heat source, a second reservoir, a second heat exchanger and a second pump, wherein the first reservoir includes a first phase change material characteristic part, and the second reservoir includes a second phase change material characteristic part.

[0058] According to one embodiment, (a) the first reservoir includes a first coolant container, and the first phase change material feature includes a first compartment retained in the first coolant container and a first phase change material in the first compartment, and (b) the second reservoir includes a second coolant container, and the second phase change material feature includes a second compartment retained in the second coolant container and a second phase change material in the second compartment.

[0059] According to one embodiment, the first phase change material has a phase change temperature below 15 degrees Celsius in the cooling circuit.

[0060] According to one embodiment, the second phase change material has a phase change temperature between 15 and 90 degrees Celsius.

[0061] According to one embodiment, the first phase change material is 14 carbon paraffin wax and the second phase change material is 28 carbon paraffin wax.

Claims

1. A multifunctional reservoir for a secondary loop climate control system, comprising: Coolant container; a chamber, said chamber being retained in said coolant container; and a phase change material, the phase change material being in the compartment; It also includes an inlet port and an outlet port on the coolant container and a modulation function feature at one of the inlet port and the outlet port to adjust the coolant flow rate; The modulation function feature is a pulse width modulated solenoid valve to control the frequency or opening of the valve and the coolant flow rate according to the desired flow rate determined by the required heat exchanger capacity, heat exchanger geometry, air inlet conditions and coolant inlet conditions.

2. The multifunctional reservoir of claim 1, wherein the phase change material has a phase change temperature below 15 degrees Celsius for the cooling circuit and a phase change temperature between 15 and 90 degrees Celsius for the heating circuit.

3. The multifunctional reservoir according to claim 1 or 2, wherein the phase change material is selected from the first group of materials consisting of paraffin or salt hydrate.

4. The multifunctional container of claim 3, wherein the compartment comprises an outer wall made of a second group of metallic materials, the second group of metallic materials consisting of aluminum, copper, stainless steel, and carbon steel.

5. A secondary loop air conditioning system comprising: a refrigerant circuit adapted to circulate refrigerant between the compressor, the condenser, the expansion device, and the cryocooler; and a coolant circuit adapted to circulate coolant between the cryocooler, the pump, the first cooler, and the reservoir having an integrated phase change material feature; wherein the reservoir comprises a coolant container and the integrated phase change material feature comprises a capsule retained in the coolant container and a phase change material in the capsule; It also includes an inlet port and an outlet port in the coolant container, and a modulation function feature at one of the inlet port and the outlet port for adjusting the coolant flow rate, wherein the modulation function feature is a pulse width modulated solenoid valve to control the frequency or opening of the valve and the coolant flow rate according to the desired flow rate determined by the required heat exchanger capacity, heat exchanger geometry, air inlet conditions and coolant inlet conditions.

6. The secondary loop air conditioning system of claim 5, wherein the phase change material is selected from a first group of materials consisting of paraffin wax or salt hydrate.

7. The secondary loop air conditioning system of claim 6, wherein the compartment includes an outer wall made of a material selected from a second group of metallic materials, the second group of metallic materials consisting of aluminum, copper, stainless steel, and carbon steel.

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